The causal relationship between leisure sedentary behaviors (LSBs) and chronic kidney disease, diabetes and related complications is still equivocal. In this study, we performed two-sample Mendelian randomization for declaring the potential causal association between LSBs and these diseases and summarized the causal estimates.

In this study, we used GWAS summary statistics from the public database for exposures (LSB: television watching, computer use, and driving) and outcomes (chronic kidney diseases, diabetes mellitus, and related complications). To ensure reliable results for this study, we applied several methods including IVW, MR-Egger, and weighted median for the regression process; MR-Egger intercept test, Cochran's Q test, 'leave-one-out' analysis and MR-PRESSO test were used to detect horizontal pleiotropy and heterogeneity for sensitivity analysis.

Television watching was harmful of CKD (OR = 1.26, 95%CI 1.09-1.44; p = 0.0011), T2D (OR = 1.82, 95%CI 1.48-2.24; p = 1.67e - 08) and DM (OR = 2.26, 95%CI 1.75-2.93; p = 6.44e - 10). No horizontal pleiotropy was detected in MR-Egger intercept test (p value > 0.05) and there were no influential SNPs based on 'leave-one-out' analysis.

Mendelian randomization estimates in our study genetically predicted the causal effect between television watching and CKD, T2D, and DM. However, we cannot get the definitive causal effect of television watching and other related complications, further studies need to be done to explore the mechanism of action of sedentary behavior on the complications of diabetes and chronic kidney disease.

Vagal parasympathetic dysfunction is strongly associated with impaired exercise tolerance, indicating that coordinated autonomic control is essential for optimizing exercise performance. This study tested the hypothesis that autonomic neuromodulation by non-invasive transcutaneous vagus nerve stimulation (tVNS) can improve exercise capacity in humans.

This single-centre, randomized, double-blind, sham-controlled, crossover trial in 28 healthy volunteers evaluated the effect of bilateral transcutaneous stimulation of vagal auricular innervation, applied for 30 min daily for 7 days, on measures of cardiorespiratory fitness (peak oxygen consumption (VO2peak)) during progressive exercise to exhaustion. Secondary endpoints included peak work rate, cardiorespiratory measures, and the whole blood inflammatory response to lipopolysaccharide ex vivo.

tVNS applied for 30 min daily over 7 consecutive days increased VO2peak by 1.04 mL/kg/min (95% CI: .34-1.73; P = .005), compared with no change after sham stimulation (-0.54 mL/kg/min; 95% CI: -1.52 to .45). No carry-over effect was observed following the 2-week washout period. tVNS increased work rate (by 6 W; 95% CI: 2-10; P = .006), heart rate (by 4 bpm; 95% CI: 1-7; P = .011), and respiratory rate (by 4 breaths/min; 95% CI: 2-6; P < .001) at peak exercise. Analysis of the whole blood transcriptomic response to lipopolysaccharide in serial samples obtained from five participants showed that tVNS reduced the inflammatory response.

Non-invasive vagal stimulation improves measures of cardiorespiratory fitness and attenuates inflammation, offering an inexpensive, safe, and scalable approach to improve exercise capacity.

High-intensity interval training (HIIT) in hypoxia has demonstrated superior increases in aerobic capacity (VO2 max) adaptations, but this has not been explored in distance runners. This study examined the methodological and VO2 max adaptations of HIIT under different altitude conditions in distance runners. We searched the PubMed, ProQuest, Europe PMC, ScienceDirect, and Cochrane databases until August 2024. Among the 1183 reviewed studies, six studies were included. The PEDro score determined the methodological quality, and a meta-analysis was performed using Jamovi software. The results revealed that VO2 max improved more in hypoxic (4.4%-13%) HIIT than in normoxic (1%-8.3%) HIIT. The meta-analysis results revealed that the effect of HIIT under hypoxia on the VO2 max overall standardized mean difference (SMD) was 0.68, with a 95% confidence interval [0.3, 1.06], p < 0.001. Conversely, the pooled SMD was not related to the type of hypoxia (p = 0.4), training status (p = 0.36), intervention week (p = 0.82), and sex (p = 0.32). In conclusion, HIIT under hypoxia achieves a greater VO2 max improvement than normoxia. Endurance athletes and coaches could plan to benefit from such training. However, studies on females using different HIIT protocols and participants at different natural altitudes are limited. This review is registered under the PROSPERO CRD42024578473.

We investigated the effects of high-intensity intermittent cross-training (HIICT) on maximal oxygen uptake (V ˙ O2max). The HIICT consisted of alternating intermittent 20-s treadmill running (1st, 3rd, 5th, and 7th bouts) and 20-s bicycle exercise (2nd, 4th, and 6th bouts) with a 10-s rest period. Each intensity for running and bicycling of the HIICT corresponded to an oxygen demand of ∼160% and ∼170% of theV ˙ O2max, respectively. Fifteen healthy young males (aged [24 ​± ​1] yrs) were randomly assigned to training (TG, n ​= ​8) and non-training control (CG, n ​= ​7) groups. The TG completed this HIICT daily 4 days/week for 6 weeks. Significant group ​× ​time interactions were observed for both the running and bicyclingV ˙ O2max (p ​< ​0.001 each). After the training, theV ˙ O2max for both running ([57.4 ​± ​4.8] mL·kg-1·min-1) and bicycling ([50.6 ​± ​3.7] mL·kg-1·min-1) in the TG were significantly higher than those for running ([50.1 ​± ​3.1] mL·kg-1·min-1) and bicycling ([43.7 ​± ​3.6] mL·kg-1·min-1) in the CG, respectively (p ​< ​0.01 each). Post-hoc tests revealed a significant increase inV ˙ O2max for running and bicycling in the TG after the HIICT (p ​< ​0.001 each) but no significant difference in the CG. These results demonstrated that the newly developed HIICT increases theV ˙ O2max for both running and bicycling.

Recent pre-clinical evidence suggests that the tryptophan metabolite 3-hydroxyanthranilic acid (3-HAA) and the related enzyme activity along the kynurenine metabolic pathway (KP) are associated with lifespan extension. We aimed to translate these findings into humans and expose exercise training as a potential non-pharmacological intervention to modulate this metabolic hub.

To explore whether recent pre-clinical findings might also be of relevance for humans, we analyzed the evolutionary conservation of KYNU and HAAO, the two core KP enzymes associated with 3-HAA. In a cross-sectional analysis of young-to-middle-aged adults (N = 84), we examined potential associations of serum 3-HAA and its precursor anthranilic acid with age. We then investigated whether 26 weeks of endurance exercise (increasing intensity (INC) during the intervention period (n = 17) vs. conventional moderate continuous training (CON) matched for energy expenditure (n = 17)) impacted 3-HAA levels, related metabolic ratios, and other KP metabolites.

We demonstrate that the core KP enzymes associated with 3-HAA are evolutionarily conserved in humans. Serum 3-HAA and its precursor anthranilic acid were consistently associated with age in young-to-middle-aged adults. Both exercise modes tested induced an increase in 3-HAA levels of 134% (p < 0.001) and 85% (p < 0.001) compared with baseline, respectively, without a significant time*group interaction effect.

We translate the association between systemic 3-HAA levels and age from animal models into humans and highlight longer-term exercise training as an efficient strategy to boost systemic 3-HAA levels in middle-aged adults. Our findings open promising research avenues concerning the mediating role of 3-HAA in training adaptations, health, and longevity.

While it is well-established that a period of interval training performed at near maximal effort, such as speed endurance training (SET), enhances intense exercise performance in well-trained individuals, less is known about its effect on cardiac morphology and function as well as blood volume. To investigate this, we subjected 12 Under-20 Danish national team ice hockey players (age 18 ± 1 years, mean ± SD) to 4 weeks of SET, consisting of 6-10 × 20 s skating bouts at maximal effort interspersed by 2 min of recovery conducted three times weekly. This was followed by 4 weeks of regular training (follow-up). We assessed resting cardiac function and dimensions using transthoracic echocardiography and quantified total blood volume with the carbon monoxide rebreathing technique at three time points: before SET, after SET and after the follow-up period. After SET, stroke volume had increased by 10 (2-18) mL (mean (95% CI)), left atrial end-diastolic volume by 10 (3-17) mL, and circumferential strain improved by 0.9%-points (1.7-0.1) (all P < 0.05). At follow-up, circumferential strain and left atrial end-diastolic volume were reverted to baseline levels, while stroke volume remained elevated. Blood volume and morphological parameters for the left ventricle, including mass and end-diastolic volume, did not change during the study. In conclusion, our findings demonstrate that a brief period of SET elicits beneficial central cardiac adaptations in elite ice hockey players independent of changes in blood volume.

This study investigates associations between changes in 800 m time trial performance in running or ski ergometer double poling, and changes in physiologic variables after a seven-week observational period. Forty six athletes ranging from recreational to elite level, participated in either a run (RUN) or a ski ergometer (SKI) observational study.

The participants performed pre- and post-tests in; 800-m time trial (800TT), 100-m time trial (MSS or MSP), peak oxygen uptake (VO2peak), oxygen cost of running (CR) or double poling (CDP), time to exhaustion (TTE) at 130% maximal aerobic speed (MAS) or maximal aerobic power (MAP), and maximal accumulated oxygen deficit (MAOD) in SKI. They also performed one repetition maximum (1RM), half-squat (RUN) or 1RM lat pull-down (SKI).

Moderate correlations were found between changes in both MAP and maximal strength and changes in 800TT for SKI (r = - 0.51 and r = - 0.51, respectively, p < 0.05). For RUN, MAS and the 0.8 MAS + 0.2 MSS equation correlated (r = - 0.71 and r = - 0.73, respectively, p < 0.01) with 800TT. VO2peak was the most important contributor to MAS improvements (RUN) while CDP was the most important contributor to MAP improvements (SKI). No correlations were found between changes in TTE at 130% MAS or MAP and, or MAOD, and changes in 800TT, for neither RUN nor SKI. The results from the present study suggest focusing on training to improve maximal oxygen uptake (VO2max), work economy and maximal sprint speed to improve performance in middle-distance running and ski sprinting.

The effects that exercise at altitude has on the neurological system are diverse and still not well studied, and range from metabolic adaptations to modification of cerebral blood flow and neurotransmitters. In this review we summarise changes with exercise intensity, the implications of ascent, cognitive impairment, psychosis-like symptoms, the role of exercise in the development and prevention of AMS, and use of free radical scavengers to enhance sports performance and acclimatization.

We discuss the impact of oxidative stress in hypobaric hypoxia and reactive oxygen species (ROS) production and its consequences, with special focus on exercise at altitude. Finally we consider how moderate intensity exercise could help prevent AMS, and the necessity of research on high intensity exercise with elevated rate of ascent, the development of specific tools of cognitive assessment, and the role of free-radical scavengers in the prevention of AMS and neurological symptoms.

The aim of this study was to determine the effect of a step load periodisation protocol for the rehabilitation of the anterior cruciate ligament (ACL) based on the variables of both the tempo of movement and time under tension (TUT) in normobaric hypoxia using a case study. Introduction: We verified the influence of variables such as time under tension (TUT) and the tempo of movement in hypoxia on the concentration of insulin-like growth factor 1 (IGF-1), growth hormone (GH), and erythropoietin (EPO). The effectiveness of the protocol also concerned variables such as peak torque of the knee flexors and extensors and maximum oxygen uptake (VO2max), as well as body composition analysis. Methods: The study used a 28-year-old judoka athlete from the national team, competing in the weight category up to 73 kg. Results: The use of short partial rest breaks between series (80s) in combination with six exercises in four series and a hypoxic environment (FiO2 = 15%) significantly increased metabolic stress, resulting in the highest increase in GH and IGF in the main phase of accumulation of the 3:1 step load. During 16 running sessions, the rehabilitated athlete achieved a significant increase in individual variables in the running test. Conclusions: The combination of a hypoxic environment combined with a periodized rehabilitation protocol can induce a number of positive hormonal, circulatory and respiratory reactions as well as positively influence muscle asymmetry, which can ultimately shorten the time it takes for an athlete to return to sport (RTS).

Endurance exercise intensities can be categorized into moderate, heavy, and severe domains based on physiological responses during incremental exercise testing. Since the evaluation of metabolic thresholds is not always possible, this study assessed the accuracy of fixed intensity anchors to estimate lactate thresholds.

165 (64 females, 101 males) recreational runners performed a maximal incremental treadmill test. The first (LT1) and second (LT2) lactate thresholds were determined as percentages of maximum heart rate (HR), oxygen consumption (VO2), and running speed, alongside the rating of perceived exertion (RPE). Sex-specific mean values were used to determine the threshold intensities and to analyze the error magnitude for each method.

Females had a higher relative HR, VO2, and speed at LT1 compared to males (p < 0.001). In the pooled data, the mean absolute error for estimating LT1 varied from 0.6 to 0.8 km/h for speed and 4.9-7.4 bpm for HR, while LT2 errors ranged from 0.4 to 0.8 km/h and 2.8-5.2 bpm, respectively. The speed-derived estimations yielded the smallest error magnitudes, while the RPE-derived estimations were the least accurate. Estimating the maximum speed increased the respective errors to 1.0 km/h and 8.4 bpm for LT1, and to 1.1 km/h and 6.7 bpm for LT2.

LT1 occurred at higher relative intensity in females, suggesting a need for sex-specific intensity anchors. The speed-derived estimates were the most accurate, but the estimation of maximum values impaired the prediction accuracy. Thus, the optimal method also depends on the availability of the maximum values.

While regular exercise training is known to decrease oxidative stress (OS) and enhance antioxidant functions in adults, limited data exist on OS responses in the pediatric population. This study aimed to investigate the effects of high-intensity functional training (HIFT) on oxidative stress and physical performance in adolescent soccer players. In this randomized controlled trial, 20 well-trained adolescent soccer players were divided into HIFT (n = 10) and moderate-intensity soccer technical training (MITT, n = 10) groups. Both groups trained for 8 weeks (3 days/week). Oxidative stress biomarkers (MDA, 8-OHDG, H2O2, GPx, CAT) and physical performance (VO2peak, vertical jump height [VJH], maximal explosive power [MEP]) were assessed pre- and post-intervention. Repeated measure mixed ANOVA (2 × 2) with a significance level of P < 0.05 was used to determine differences between and within subjects. The main effect of interaction was significant for VO2peak, VJH and MEP (P < 0.05). The main effect of interaction was not significant for CAT, 8-OHDG, GPx, H2O2 and MDA (P > 0.05). Following intervention, VO2peak and VJH performance in the HIFT were significantly higher than MITT (P < 0.05). MDA and H2O2 in the HIFT decreased significantly (P < 0.05), but no significant changes were observed in the MITT (P > 0.05). CAT activity decreased significantly (P < 0.05), while GPx activity increased significantly (P < 0.05) in both groups. 8-OHDG did not show significant changes in both groups (P > 0.05). Eight weeks of HIFT did not cause greater OS compared to MITT, while could improve physical performance parameters. These findings suggest that HIFT is a viable and time-efficient training strategy for enhancing athletic performance in youth sports. Trial registration: The present study was a randomized controlled trial (registration number: IRCT20190530043762N1, 25/09/2019, Iran).

Sports nutrition guidelines recommend carbohydrate (CHO) intake be individualized to the athlete and modulated according to changes in training load. However, there are limited methods to assess CHO utilization during training sessions.

We aimed to (1) quantify bivariate relationships between both CHO and overall energy expenditure (EE) during exercise and commonly used, non-invasive measures of training load across sessions of varying duration and intensity and (2) build and evaluate prediction models to estimate CHO utilization and EE with the same training load measures and easily quantified individual factors.

This study was undertaken in two parts: a primary study, where participants performed four different laboratory-based cycle training sessions, and a validation study where different participants performed a single laboratory-based training session using one of three exercise modalities (cycling, running, or kayaking). The primary study included 15 cyclists (five female; maximal oxygen consumption [ V ˙ O2max], 51.9 ± 7.2 mL/kg/min), the validation study included 21 cyclists (seven female; V ˙ O2max 53.5 ± 11.0 mL/kg/min), 20 runners (six female; V ˙ O2max 57.5 ± 7.2 mL/kg/min), and 18 kayakers (five female; V ˙ O2max 45.6 ± 4.8 mL/kg/min). Training sessions were quantified using six training load metrics: two using heart rate, three using power, and one using perceived exertion. Carbohydrate use and EE were determined separately for aerobic (gas exchange) and anaerobic (net lactate accumulation, body mass, and O2 lactate equivalent method) energy systems and summed. Repeated-measures correlations were used to examine relationships between training load and both CHO utilization and EE. General estimating equations were used to model CHO utilization and EE, using training load alongside measures of fitness and sex. Models were built in the primary study and tested in the validation study. Model performance is reported as the coefficient of determination (R2) and mean absolute error, with measures of calibration used for model evaluation and for sport-specific model re-calibration.

Very-large to near-perfect within-subject correlations (r = 0.76-0.96) were evident between all training load metrics and both CHO utilization and EE. In the primary study, all models explained a large amount of variance (R2 = 0.77-0.96) and displayed good accuracy (mean absolute error; CHO = 16-21 g [10-14%], EE = 53-82 kcal [7-11%]). In the validation study, the mean absolute error ranged from 16-50 g [15-45%] for CHO models to 53-182 kcal [9-31%] for EE models. The calibrated mean absolute error ranged from 9-20 g [8-18%] for CHO models to 36-72 kcal [6-12%] for EE models.

At the individual level, there are strong linear relationships between all measures of training load and both CHO utilization and EE during cycling. When combined with other measures of fitness, EE and CHO utilization during cycling can be estimated accurately. These models can be applied in running and kayaking when used with a calibration adjustment.

This study investigated the effect of sprint-interval training combined with post-exercise blood flow restriction (i.e., SIT + BFR) on pulmonary gas exchange and microvascular deoxygenation responses during ramp incremental (RI) cycling.

Nineteen healthy, untrained males (mean ± SD age: 24 ± 5 years; height: 178 ± 6 cm; body mass: 77.0 ± 10.7 kg) were assigned to receive 4 weeks of SIT or SIT + BFR. Before and after the intervention period, each participant completed a RI cycling test for determination of peak oxygen uptake (V ˙ O 2peak ) and the gas exchange threshold (GET) with deoxygenated heme (Δdeoxy[heme]) and tissue oxygenation index (TOI) measured by near-infrared spectroscopy (NIRS) in vastus lateralis (VL) muscle.

RelativeV ˙ O 2peak increased by 7% following both interventions (P ≤ 0.03). SIT + BFR increased peak Δdeoxy[heme] when normalized relative to leg arterial occlusion (PRE: 57.3 ± 13.0 vs. POST: 62.0 ± 13.2%; P = 0.009) whereas there was no significant difference following SIT (PRE: 64.9 ± 14.3 vs. POST: 71.4 ± 11.7%; P = 0.17). Likewise, TOI nadir decreased at exhaustion following SIT + BFR (PRE: 56.9 ± 9.1 vs. POST: 51.4 ± 9.2%; P = 0.002) but not after SIT (PRE: 58.5 ± 7.1 vs. POST: 56.3 ± 8.2%; P = 0.29). The absolute cycling power at the GET increased following SIT + BFR (PRE: 108 ± 13 vs. POST: 125 ± 17 W, P = 0.001) but was not significantly different following SIT (PRE: 112 ± 7 VS. POST: 116 ± 11 W, P = 0.54).

The addition of post-exercise BFR to SIT alters the mechanism underlying the enhancement inV ˙ O 2peak by increasing the peak rate of muscle fractional O2 extraction in previously untrained males.

Regular exercise is a practical non-pharmacological approach to maintaining physical and mental health through rehabilitation and prevention of chronic diseases due to its cardiovascular, cardiorespiratory, neurological, and neuromuscular benefits. Despite awareness of the benefits of exercise, a "lack of time" has proven to be the most common impediment to regular activity. Thus, a time-efficient and potentially enjoyable training modality with growing popularity is high-intensity interval training (HIIT). HIIT incorporates intermittent bouts of work and recovery intervals performed at an intensity close to maximal oxygen consumption (VO2max). HIIT is considered to have equivalent or superior benefits compared to moderate-intensity continuous training (MICT). This narrative review focuses on the mechanisms of Citrulline Malate (CM) supplementation and various modes of HIIT on exercise performance. CM serves as a nitric-oxide enhancer leading to improved aerobic and anaerobic exercise performance by increasing muscle adenosine triphosphate (ATP) production, vasodilation, and blood flow to the active musculature and boosting work capacity. This article reviews the mechanisms related to CM supplementation and different modes of HIIT on exercise performance. Even though a single, acute 8 g dose of CM has been recommended, its mechanism of action remains to be seen due to the synergistic impact of both components (citrulline and malate). Moreover, the limited evidence for the standard level of supplement use and source of purchase results in athletes' self-prescription of supplements. Therefore, to reduce the risk of accidental doping or toxicity, further studies should continue to investigate the optimal dose, timing, mechanism of action, as well as reliable sources of purchase for CM consumption.

This review assesses the role of wearable technologies in pain management, emphasizing their capability to transcend subjective pain evaluations with objective functional outcome tracking. We explore the types and veracity of health metrics wearable devices track, illustrating how this technological evolution can significantly enhance patient care in the context of chronic pain prevention and management.

The advancements in modular wearable technology offer new avenues to track a variety of health outcomes, including aerobic capacity, physical activity, stress, and sleep quality. This provides objective measurements that can aid in the management of chronic conditions and can offer a more comprehensive assessment of a patient's pain and function. Although the initial approach to pain management that emphasized pain as the fifth vital sign had unintended devastating consequences, leveraging wearable technology for objective outcomes tracking presents an opportunity to optimize pain management strategies. Wearable technologies capture functional metrics that provide insight into many aspects of the biopsychosocial model of pain. Utilizing function as the key performance indicator has the potential to improve treatment outcomes and, ultimately, patient care.

Higher work rates may be sustainable when maintaining target rating of perceived exertion (RPE) compared to maintaining target heart rate (THR) during high-intensity interval training (HIIT) exercise in hot conditions, but may also result in greater thermal strain and cardiovascular drift, as well as greater decrements in maximal oxygen uptake (V ˙ O2max).

To test the hypotheses that maintaining target RPE compared to THR during HIIT in the heat results in 1) smaller work rate adjustments, 2) greater thermal and cardiovascular strain, and 3) larger decreases inV ˙ O2max.

Eight adults (4 women) completed a graded exercise test on a cycle ergometer in 22°C and then 4 cycling trials in 35°C, consisting of an 8-min warm-up at 70% maximal heart rate (HRmax) or 12 RPE followed by 1 (15HR and 15RPE) or 5 (43HR and 43RPE) rounds of HIIT (1 round = 4 min work at 90% HRmax or 17 RPE and 3 min recovery at 70% HRmax or 12 RPE) totaling 15 min or 43 min of exercise, respectively. Each trial ended with a GXT to measureV ˙ O2max.

In the 43-min trials work rate decreased from the first to the fifth work interval in both conditions, but by a non-significant, yet moderately larger (ES = 0.53) amount during 43HR (46 ± 29 W) compared to 43RPE (30 ± 28 W). From the first to fifth work interval HR increased over time by 12 b⋅min-1 in 43RPE (p < 0.001), but did not increase during 43HR (p = 0.36). Rectal temperature increases were not different between conditions (43HR = 0.7°C, p < 0.001; 43RPE = 0.8°C, p < 0.001).V ˙ O2max decreased 15.6% (ES = 0.41) between 15RPE and 43RPE (p = 0.005), but it was not different over time during the HR-based trials [6.5%, ES = 0.16 (α adjusted for multiple comparisons = 0.0125) p = 0.03].

Maintaining target RPE and THR require considerable declines in work rate during HIIT in the heat, with ∼53% larger declines needed to maintain THR. The mitigation of cardiovascular drift in the THR trial may have contributed to the preservation ofV ˙ O2max.

Combining aerobic and strength training may attenuate neuromuscular adaptations, particularly when both target the same muscle group. This study assessed whether separating the training modalities by muscle groups mitigates this interference. Ninety-six participants (56 males and 40 females) completed a 12-week intervention, divided into three groups: (1) LHLS (lower-body high-intensity interval (HIIT) and strength training), (2) LHUS (lower-body HIIT and upper-body strength training), and (3) LSUS (lower- and upper-body strength training). Maximal (1RM) and explosive strength were assessed using load-velocity profiling, with mean propulsive velocity (MPV) at 30%, 50%, 70%, and 90% of 1RM as a measure of explosive strength. Muscle cross-sectional area (CSA) of the M. vastus lateralis and M. pectoralis major was measured using panoramic ultrasound. Lower-body adaptations were compared between LHLS and LSUS, and upper-body adaptations were compared between LHUS and LSUS. MPV at 70% and 90% of 1RM for the squat (LHLS and LSUS) and bench press (LHUS and LSUS) showed improvements (p < 0.050), with no significant between-group differences. Squat 1RM improved in both LHLS and LSUS, and bench press 1RM increased in both LHUS and LSUS (all p < 0.001). M. vastus lateralis CSA increased in LHLS (p = 0.029) but not in LSUS, whereas M. pectoralis major CSA increased in both LHUS and LSUS (p < 0.001), with no between-group differences. No sex-based differences were observed. Concurrent aerobic and strength training does not impair explosive strength, maximal strength, or muscle hypertrophy, regardless of whether the same or separate muscle groups are targeted.

Epidemiological evidence suggests low-frequency physical activity provides health benefits, but the physiological impacts of weekly training frequency are understudied. We investigated whether "Weekend Warrior" (WW) training was inferior to traditional, high-frequency (HF) training for improving maximal oxygen uptake (V̇O2max). The secondary aim was to assess integrative physiological adaptations to each protocol. Twenty-eight sedentary-to-recreationally-active adults aged 18-45 years (14 males and 14 females) were randomized to perform 8-weeks of HF or WW training on a cycle ergometer (either four or two sessions weekly, respectively), consisting of continuous and interval exercise, with intensity and volume matched between groups. WW training was not inferior to HF training for improving V̇O2max (mean ± standard deviation; WW: 43.5 ± 6.5 vs. 47.8 ± 6.4 mL/kg/min; HF: 42.3 ± 6.2 vs. 47.3 ± 6.7; main effect of training, p < 0.001). Severe domain cycling time-to-task-failure also increased in both groups (WW: 3.7 ± 1.6 vs. 8.6 ± 3.2 min; HF: 3.5 ± 0.9 vs. 7.7 ± 2.8; main effect of training: p < 0.001). Frequency did not affect improvements in hemoglobin mass (WW: 771 ± 203 vs. 790 ± 189 g; HF: 754 ± 185 vs. 765 ± 202; main effect of training: p = 0.043) or skeletal muscle oxidative capacity (WW: 0.034 ± 0.008 vs. 0.045 ± 0.015 s-1; HF: 0.036 ± 0.011 vs. 0.041 ± 0.010; main effect of training: p = 0.002), nor did it influence improvements in cardiorespiratory, substrate oxidation, voluntary muscle contractile, and perceptual responses to submaximal exercise (interaction effect: p > 0.05 for all outcomes). Eight weeks of training improved V̇O2max and a wide range of physiological outcomes with no difference between training frequencies, suggesting that the distribution of weekly exercise volume has a limited effect during short-term training. Trial Registration: This trial was registered at ClinicalTrials.gov identifier: NCT05908578.

Law enforcement agencies require minimum fitness standards to safeguard their officers and training staff. Firearms instructors (FI) are expected to maintain the same standards as their operational counterparts. This study aimed to quantify the daily physiological demands placed on FI.

19 FI (45 ± 5 years) completed occupational tasks whilst wearing heart rate (HR) monitors for a minimum 10 days. Maximal oxygen consumption (VO2max) testing was conducted on FI during a treadmill test (TT) and a multistage shuttle test (ST). Linear regression models were used to model the relationship between VO2 and HR throughout the TT. This model was applied to HR data from occupational tasks to infer oxygen consumption. Repeated Measures ANOVAs were used to compare time spent in VO2max equivalent zones throughout.

The VO2max achieved during ST (45.1 ± 5.6 ml/kg/min) was significantly higher than TT (39 ± 3 ml/kg/min) (p = 0.014). Time to exhaustion (TTE) was sooner on ST (06:26 min) compared to TT (13:16 min) (p < .001). FI spent ~85% of occupational time with an oxygen demand ≤20 ml/kg/min (p < .005). The most intense occupational tasks saw FI achieve VO2max ≥30 ml/kg/min, but <40 ml/kg/min.

Using ST to assess cardiorespiratory fitness resulted in a quicker TTE and a higher VO2max. Predominantly, FI occupational tasks are low intensity with sporadic exposures requiring a VO2max of >40 ml/kg/min. To safeguard FI from occupational-related cardiorespiratory or long-term health issues, it is intuitive to suggest fitness standards should exceed a VO2max of 40 ml/kg/min.

Physical exercise is a cornerstone for preventing diet-induced obesity, while it is unclear whether physical exercise could offset high-fat, high-calories diet (HFCD)-induced cardiac dysfunction. Here, mice were fed with HFCD and simultaneously subjected to physical exercise. As expected, physical exercise prevented HFCD-induced whole-body fat deposition. However, physical exercise exacerbated HFCD-induced cardiac damage. Further metabolomic analysis results showed that physical exercise induced circulating lipid redistribution, leading to excessive cardiac lipid uptake and lipotoxicity. Our study provides valuable insights into the cardiac effects of exercise in mice fed with HFCD, suggesting that counteracting the negative effect of HFCD by simultaneous physical exercise might be detrimental. Moreover, inappropriate physical exercise may damage certain organs even though it leads to weight loss and overall metabolic benefits. Of note, the current findings are based on animal experiments, the generalizability of these findings beyond this specific diet and mouse strain remains to be further explored.

To explore the relationships between performance variables and physiological variables in a short-time (2-3 min) cycling time trial (TT) on a cycle ergometer.

Fifteen young elite cyclists (age: 17.3 ± 0.7 years, maximal oxygen uptake (VO2max): 76.6 ± 5.2 mL⋅kg-1⋅min-1) participated in this study. Maximal aerobic power (MAP), maximal anaerobic power (MANP), time to exhaustion at 130% of maximal aerobic power (TTE), maximal accumulated oxygen deficit (MAOD) in the TT, anaerobic power reserve (APR) and lactate threshold (LT) was tested. MAP was calculated as VO2max/oxygen cost of cycling (CC), MANP was determined as mean power output (W) during a 10 s maximal cycling sprint test, and MAOD was calculated as (VO2 demand - VO2 measured) ∙ time. APR was calculated as the relative difference between MAP and MANP.

There was a strong correlation between MAP and TT time (r = -0.91, p < 0.01) with a standard error of estimate (SEE) of 4.4%, and a moderate association between MANP and TT time (r = -0.47, p = 0.04). Neither MAOD, TTE, LT nor APR correlated with TT.

MAP was highly correlated with TT with a SEE of 4.4%. Since neither TTE nor MAOD correlated with TT, this indicates that these two variables do not play a significant role in differentiating short-time endurance cycling performance. We suggest training for improving MAP and, or MANP to improve short-time endurance cycling performance.

Meta-analysts have found that high-intensity interval training (HIIT) improves physical performance, but limited evidence exists regarding its effects on highly trained athletes, measures beyond maximum oxygen uptake (V ˙ O2max), and the moderating effects of different types of HIIT. In this study, we present meta-analyses of the effects of HIIT focusing on these deficits.

The effects of 6 types of HIIT and other moderators were derived from 34 studies involving highly trained endurance and elite athletes in percent units via log-transformation from separate meta-regression mixed models for sprint, time-trial, aerobic/anaerobic threshold, peak speed/power, repeated-sprint ability,V ˙ O2max, and exercise economy. The level of evidence for effect magnitudes was evaluated based on the effect uncertainty and the smallest important change of 1%.

Compared with control training, HIIT showed good to excellent evidence for the substantial enhancement of most measures for some athlete subgroups in practically important study settings defined by effect moderators (maximum of 12.6%, for endurance female athletes after 6 weeks of aerobic traditional long intervals). The assessment of the moderators indicated good evidence of greater effects as follows: with more aerobic types of HIIT forV ˙ O2max (+2.6%); with HIIT added to conventional training for most measures (+1.1-2.3%); during the competition phase forV ˙ O2max (+4.3%); and with tests of longer duration for sprint (+5.5%) and time trial (+4.9%). The effects of sex and type of athlete were unclear moderators. The heterogeneity of HIIT effects within a given type of setting varied from small to moderate (standard deviations of 1.1%-2.3%) and reduced the evidence of benefit in some settings.

Although athletes in some settings can be confident of the beneficial effects of HIIT on some measures related to competition performance, further research is needed. There is uncertainty regarding the mean effects on exercise economy and the modifying effects of sex, duration of intervention, phase of training, and type of HIIT for most measures.

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=236384.

The purpose of this study was to evaluate the effects of a microcycle of high-intensity interval training (HIT) sessions with multiple short work intervals followed by an active recovery period, compared to a similar duration of regular training, on determinants and indicators of endurance performance in well-trained cyclists. The participants in the BLOCK group performed a 6-day HIT microcycle including five HIT sessions (5 × 8.75-min 30/15 s short intervals) followed by a 6-day active recovery period with reduced training load, while the regular training group (REG) performed 12 days of their regular training, including four HIT sessions. Physiological testing was performed before and after the training periods. From pre- to post- intervention, BLOCK demonstrated significantly larger improvements than REG in mean power output (PO) during the last min of the maximal oxygen uptake (VO2max) test (POVO2max) (3.7 vs. 0.7%, p = 0.009, and effect size (ES) = 1.00) and mean PO during the 10-s sprint (2.8 vs. 1.9%, p = 0.028, and ES = 0.63). No significant differences between BLOCK and REG were observed for VO2max, PO at 4 mmol·L-1 [blood lactate] (PO4mmol), 15-min maximal mean power output (PO15-min), and gross efficiency (p = 0.156-0.919). However, there was a tendency for larger improvements in the performance index (calculated from the main performance indicators POVO2max, PO4mmol, and PO15-min) in BLOCK compared to REG (2.9% vs. 1.2%, p = 0.079, and ES = 0.71). A 6-day high-intensity short-interval microcycle followed by a 6-day active recovery period induces improvements in endurance performance indicators compared to regular training, demonstrating its potential as an efficient strategy for endurance training in well-trained cyclists.

Although exercise is medicine for outpatients with schizophrenia, it is unclear if one-year adherence-supported exercise leads to a "tipping point", at which the exercise becomes a routine manifested as life-long training in the patient group.

Forty-eight outpatients (28 men/20 women: 35 ± 11 (mean ± SD) years) with schizophrenia (ICD-10: F20-29) were randomised to: 1) collaborative care group (TG), performing aerobic interval (AIT; 4 × 4-min treadmill walking/running at ∼90 % peak heart rate) and leg press maximal strength training (MST; 4 × 4 repetitions at ∼90 % maximal strength [1RM]) 2d·wk.-1 for 1-year, supported by transportation and training supervision; or 2) control group (CG). Peak oxygen uptake (V̇O2peak) and walking work efficiency were measured directly along with scaled 1RM/power, anthropometry, blood pressure, and blood samples at inclusion, 1-year, and 5-years post-intervention.

The TG increased V̇O2peak (11 %, p < .01), scaled 1RM (40 %, p < .001), and power (26 %, p < .001) compared to CG after 1-year. At follow-up, no intergroup differences in these factors were observed (all p > .05). Both groups improved walking work efficiency (TG: 11 %; CG: 18 %; both p < .05) after 1-year (no intergroup difference, p > .05), but not at follow-up (both p > .05). At follow-up, HDL (high-density lipoprotein)-cholesterol (-15 %, p < .01) and glucose (26 %, p < .01) decreased/increased(respectively) more in the TG than CG. No other intergroup differences were observed in anthropometry or blood samples.

1-year adherence-supported high-intensity training improves V̇O2peak, 1RM, and power in outpatients with schizophrenia. However, the improvements in these factors key to longevity are not maintained after 5 years. These findings highlight the importance of long-lasting cost-efficient adherence support, ultimately affecting the population's prognosis.

We analyzed the interindividual heterogeneity in health responses to a supervised high-intensity interval training (HIIT) program in individuals with metabolic syndrome (MetS). Two hundred and sixty-four adults with overweight/obesity (56.3 ± 7.3 yr, body mass index: 32.3 ± 4.7 kg/m2) and MetS were randomized to a standard health care nonexercise group (CONT group, N = 58) or standard health care plus HIIT (EXER group, N = 206). HIIT intervention was performed on a cycloergometer thrice a week (43 min/session). MetS components (i.e., MetS z score), cardiorespiratory fitness (V̇o2peak), maximal cycling power (WPEAK), and body weight/composition was assessed in both groups before (0 wk) and after the intervention (16 wk). Individual responses in the EXER group were considered attributable to HIIT when the improvements were larger than twice the typical error (>2TE). TE was calculated using pre- and postintervention data from the time-matched CONT group. The percentage of participants who improved MetS z score beyond 2TE was 51% driven by reductions in blood pressure (45%) and waist circumference (48%). Blood lipids and glucose response were only 21% and 16%, respectively (participants improving beyond 2TE). Sixty percent of individuals who improved MetS z score also improved V̇o2peak (r = -0.013; P = 0.86), whereas 85% of individuals improving MetS z score also improved WPEAK (r = 0.151; P = 0.03). In summary, health providers can expect that a 16-wk HIIT program would indisputably improve MetS in approximately 50% of individuals completing the program. Finally, WPEAK better predicts which individuals would improve MetS than V̇o2peak when the direct assessment of the five MetS factors is not feasible.NEW & NOTEWORTHY Our study offers healthcare providers the expected percentage of individuals who would improve their metabolic syndrome condition after completing a standardized HIIT program (16 wk, 43 min/session, 3 days/wk). Only half of the subjects achieved indisputable improvement in their MetS z score when we accounted for biological variability and instrument errors. Detection of individuals with a positive response in MetS z score could be inferred from gains in maximal cycling power (i.e., exercise functionality).

Patients with rheumatoid arthritis (RA) have substantially elevated risk for cardiovascular diseases, and low cardiorespiratory fitness (VO2max) is a major mediator. The aim of this assessor-blinded, two-armed multicentre randomised controlled trial was to evaluate the effects of high-intensity interval training (HIIT) and strength exercise on cardiovascular health, physical fitness and overall health in patients with RA.

In total, 87 patients (86% female; aged 20-60 years) were randomly assigned to an intervention group (IG) or a control group (CG). The IG performed HIIT and strength exercise for 12 weeks. The CG was instructed to be physically active on a moderately intensive level, ≥150 min/week. Primary outcome was change in VO2max. Secondary outcomes were changes in anthropometry measures, muscle strength, overall health (Visual Analogue Scale (VAS)-Global), Patient Global Impression of Change (PGIC), pain and disease activity (Disease Activity Score in 28 joints (DAS28)).

There was a significant mean group difference of change on VO2max (3.71 mL/kg/min; 95% CI 2.16, 5.25) in favour of the IG. Significant mean group differences of change were also seen for O2-pulse (1.38; 95% CI 0.85 to 1.91), waist circumference (-2.6; 95% CI -5.09 to -0.18), 1-minute sit-to-stand (5.0; 95% CI 3.35 to 6.72), handgrip strength (28.5; 95% CI 3.80 to 52.8), overall health (-14.7; 95% CI -23.8 to -5.50) and PGIC (p<0.0001) in favour of the IG. No significant mean group differences of change were found for pain (-4.0; 95% CI -13.07 to 5.06), DAS28 (-0.25; 95% CI -0.60 to 0.10) and erythrocyte sedimentation rate (-0.64; 95% CI -3.23 to 1.90).

Supervised HIIT and strength exercise improved cardiovascular health, physical fitness and overall health without a deterioration in pain and disease activity and should be considered in patients with well-controlled RA.

NCT05768165.

Rapid regeneration after intense exercise is essential for competitive athletes. Based on this assumption, supplementation strategies, focusing on food supplements, are increasing to improve the recovery processes. One such supplement is cannabidiol (CBD) which is gaining more attention in competitive sports. However, the evidence is still lacking and there are no data available about the effect of a short-term chronic application.

A three-arm double-blind cross-over study was conducted to determine the effects of two different CBD products on performance, muscle damage and inflammatory processes in well-trained athletes. In total 17 subjects took successfully part in this study. Each subject underwent the six-day, high-intensity training protocol three times. After each training session, each subject took either a placebo or a CBD product (60 mg of oil or solubilisate). Between the intervention phases, at least four weeks of washout period was conducted. Before and after the training protocols the performance capacity in countermovement jump (CMJ), back squat (BS), bench press (BP) and 1-mile run were measured and biomarkers for muscle damage (creatine kinase, myoglobin), inflammatory processes (interleukin 6 and 10) and immune cell activity (ratios of neutrophil granulocytes, lymphocytes and, platelets) were analyzed. For statistical analyses, the current version of R and a linear mixed model was used.

It could identify different effects of the training protocol depending on performance level (advanced or highly advanced athletes) (p < .05). Regardless of the performance level, muscle damage and a reduction in performance could be induced by the training protocol. Only CBD oil was associated with a reduction in myoglobin concentration (p < .05) in advanced athletes. Concerning immune activity, a significant decrease in platelets lymphocyte ratios was observed in advanced athletes after placebo treatment (p < .05). CBD oil application showed a slight inhibitory effect (p < .10). Moreover, the reduction in performance differs between the performance levels. A significant decrease in CMJ was observed in advanced athletes and a decreasing trend in BS was observed in highly advanced athletes after placebo treatment (p < 0.10). Both CBD products do not affect performance parameters. For inflammatory parameters, no effects were observed.

It was found that the performance level of the subjects was a decisive factor and that they responded differently to the training protocol and the CBD application. However, no clear effects of either CBD product were found and further research is needed to identify the long-term effects of CBD application.

Exercise is a non-pharmacological intervention for type 2 diabetes mellitus (T2DM), including moderate-intensity continuous training (MICT) and high-intensity interval training (HIIT). Despite diverse exercise protocol variations, the impact of these variations in HIIT on T2DM anthropometrics, glycemic control, and cardiorespiratory fitness (CRF) remains unclear.

The aim was to examine the influence of HIIT protocol characteristics on anthropometrics, glycemic control, and CRF in T2DM patients and compare it to control (without exercise) and MICT.

This review is registered in PROSPERO (CRD42021281398) and follows Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The search, employing "high-intensity interval training" and "diabetes mellitus" in PubMed and Web of Science databases, with a "randomized controlled trial" filter, spanned articles up to January 2023.

Of 190 records, 29 trials were included, categorized by HIIT interval duration, training volume, and intervention period. Long-duration, high-volume, and long-term HIIT yields superior outcomes compared to control conditions for body mass, waist circumference, fasting plasma glucose, Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), glycosylated hemoglobin (%HbA1c), and CRF. The findings favored HIIT over MICT for body mass in long-duration, high-volume, and short-term intervals (mean difference [MD] - 3.45, - 3.13, and - 5.42, respectively, all p < 0.05) and for CRF in long and medium work intervals and high volume (MD 1.91, 2.55, and 2.43, respectively, all p < 0.05), as well as in medium and long-term intervention (MD 2.66 and 2.21, respectively, all p < 0.05). Regardless of specific HIIT characteristics, no differences were found in the HIIT versus MICT comparison for glycemic control.

Specific HIIT protocol characteristics influence changes in anthropometrics, glycemic control, and CRF compared to control groups. However, compared to MICT, only longer duration, higher volume, and short-term HIIT improved body mass, waist circumference, and CRF in individuals with T2DM.

Motor-cognitive training and exergaming often only reach low-to-medium intensities that limits their training efficiency. This study evaluated the physiological profile of different exercises on a novel motor-cognitive training technology designed to cover a broad range of exercise intensities. Twenty-six healthy trained adults (17 males, 23.7 ± 3.8 years) performed five motor-cognitive training tasks on the SKILLCOURT technology. Oxygen consumption (VO2), heart rate (HR), blood [lactate], perceived physical exertion (RPE) responses, and metabolic equivalent (MET) were assessed and compared to an incremental treadmill ramp test determining the maximal oxygen consumption (VO2max) and maximal heart rate (HRmax). Computer-based cognitive training served as control condition. Motor-cognitive exercises reached a higher %VO2max and %HRmax levels when compared to computer-based training (p < 0.001). Average intensity varied significantly between motor-cognitive tasks, with %VO2max ranging from 22% to 81% (p < 0.001), %HRmax from 49% to 89% (p < 0.001), METs from 3.57 to 13.37 (p < 0.001), blood [lactate] from 0.93 to 7.81 mmol·L-1 (p < 0.001), and RPE from 8.5 to 16.4 (p < 0.001). Motor-cognitive training covers a wide range of exercise intensities. This supports individual training subscription and allows high-intensity training to facilitate cardio-vascular adaptations and neural plasticity.

High-intensity training (HIT) has commonly been the most effective training method for improvement in maximal oxygen uptake (VO2max) and work economy, alongside a substantial volume of low-intensity training (LIT). The polarized training model combines both low- and high-intensity training into a specific training intensity distribution and has gained attention as a comprehensive approach. The objective of this review was to systematically search the literature in order to identify the effects of polarized training intensity distribution on VO2max, peak oxygen uptake (VO2peak), and work economy among endurance athletes. A literature search was performed using PubMed and SPORTDiscus. A total of 1836 articles were identified, and, after the selection process, 14 relevant studies were included in this review. The findings indicate that a polarized training approach seems to be effective for enhancing VO2max, VO2peak, and work economy over a short-term period for endurance athletes. Specifically, a training intensity distribution involving a moderate to high volume of HIT (15-20%) combined with a substantial volume of LIT (75-80%) appears to be the most beneficial for these improvements. It was concluded that polarized training is a beneficial approach for enhancing VO2max, VO2peak, and work economy in endurance athletes. However, the limited number of studies restricts the generalizability of these findings.

It is accepted that the metabolic response of bone tissue depends on the intensity of the mechanical loads, but also on the type and frequency of stress applied to it. Physical exercise such as running involves stresses which, under certain conditions, have been shown to have the best osteogenic effects. However, at high intensity, it can be deleterious for bone tissue. Consequently, there is no clear consensus as to which running modality would have the best osteogenic effects.

Our objective was to compare the effects of three running modalities on morphological and micro-architectural parameters on forelimb bones.

Forty male Wistar rats were randomly divided into four groups: high intensity interval training (HIIT), continuous running, combined running ((alternating HIIT and continuous modalities) and sedentary (control). The morphometry, trabecular microarchitecture and cortical porosity of the ulna, radius and humerus were analyzed using micro-tomography.

All three running modalities resulted in bone adaptation, with an increase in the diaphyseal diameter of all three bones. The combined running protocol had positive effects on the trabecular thickness in the distal ulna. The HIIT protocol resulted in an increase in both medio-lateral diameter and cortical bone area over total area (Ct.Ar/Tt.Ar) at the ulnar shaft compared with sedentary condition. Moreover, the HIIT protocol decreased the mean surface area of the medulla (Ma.Ar) according to sedentary condition at the ulnar shaft.

This study has shown that HIIT resulted in a decrease in trabecular bone fraction in favor of cortical bone area at the ulna.

Although the efficacy of interval training for improving body composition has been summarized in an increasing number of systematic reviews in recent years, discrepancies in review findings and conclusions have been observed.

This study aims to synthesize the available evidence on the efficacy of interval training compared with moderate-intensity continuous training (MICT) and nonexercise control (CON) in reducing body adiposity in apparently healthy adults.

An umbrella review with meta-analysis was performed. A systematic search was conducted in seven databases (MEDLINE, EMBASE, Cochrane Database, CINAHL, Scopus, SPORTDiscus, and Web of Science) up to October 2023. Systematic reviews with meta-analyses of randomized controlled trials (RCTs) comparing interval training and MICT/CON were included. Literature selection, data extraction, and methodological quality assessment (AMSTAR-2) were conducted independently by two reviewers. Meta-analyses were performed using a random-effects model. Subgroup analyses were conducted based on the type of interval training [high-intensity interval training (HIIT) and sprint interval training (SIT)], intervention duration, body mass index, exercise modality, and volume of HIIT protocols.

Sixteen systematic reviews, including 79 RCTs and 2474 unique participants, met the inclusion criteria. Most systematic reviews had a critically low (n = 6) or low (n = 6) AMSTAR-2 score. Interval training demonstrated significantly greater reductions in total body fat percent (BF%) compared with MICT [weighted mean difference (WMD) of - 0.77%; 95% confidence interval (CI) - 1.12 to - 0.32%] and CON (WMD of - 1.50%; 95% CI - 2.40 to - 0.58%). Significant reductions in fat mass, visceral adipose tissue, subcutaneous abdominal fat, and android abdominal fat were also observed following interval training compared to CON. Subgroup analyses indicated that both HIIT and SIT resulted in superior BF% loss than MICT. These benefits appeared to be more prominent in individuals with overweight/obesity and longer duration interventions (≥ 12 weeks), as well as in protocols using cycling as a modality and low-volume HIIT (i.e., < 15 min of high-intensity exercise per session).

This novel umbrella review with large-scale meta-analysis provides an updated synthesis of evidence with implications for physical activity guideline recommendations. The findings support interval training as a viable exercise strategy for reducing adiposity in the general population.

It has been suggested that time at a high fraction (%) of maximal oxygen uptake (VO2max) plays a decisive role for adaptations to interval training. Yet, no study has, to date, measured the % of VO2max during all interval sessions throughout a prolonged training intervention and subsequently related it to the magnitude of training adaptations. Thus, the present study aimed to investigate the relationship between % of VO2max achieved during an interval training intervention and changes in endurance performance and its physiological determinants in well-trained cyclists. Twenty-two cyclists (VO2max 67.1 (6.4) mL·min-1 ·kg-1; males, n = 19; females, n = 3) underwent a 9-week interval training intervention, consisting 21 sessions of 5 × 8-min intervals conducted at their 40-min highest sustainable mean power output (PO). Oxygen uptake was measured during all interval sessions, and the relationship between % of VO2max during work intervals and training adaptations were investigated using linear regression. A performance index was calculated from several performance measures. With higher % of VO2max during work intervals, greater improvements were observed for maximal PO during the VO2max test (R2 adjusted = 0.44, p = 0.009), PO at 4 mmol·L-1 [blood lactate] (R2 adjusted = 0.25, p = 0.035), the performance index (R2 adjusted = 0.36, p = 0.013), and VO2max (R2 adjusted = 0.54, p = 0.029). Other measures, such as % of maximal heart rate, were related to fewer outcome variables and exhibited poorer session-to-session repeatability compared to % of VO2max. In conclusion, improvements in endurance measures were positively related to the % of VO2max achieved during interval training. Percentage of VO2max was the measure that best reflected the magnitude of training adaptations.

The present study aimed to investigate the effect of two protocols of high-intensity interval exercise (HIIE) on performance fatigability and its neural and muscular determinants. On different days, 14 healthy males performed two HIIE protocols with different work and recovery durations (matched for total duration, work and recovery intensities, and density): 1) 4 × 4 min at 90% HRpeak,180-s recovery at 70% HRpeak; and 2) 16 × 1 min at 90% HRpeak, 45-s recovery at 70% HRpeak. Pre- to post-HIIE reduction in maximal voluntary isometric contraction (MVIC) was used as marker of performance fatigability, while voluntary activation (VA) and potentiated quadriceps twitch force (Qtw) as markers of the neural (i.e. central fatigue) and muscular (i.e. peripheral fatigue) determinants, respectively. In addition, pre- to post-HIIE reduction in twitch force stimulated at 100 Hz (Qtw100) and 10:100 Hz ratio (Qtw10:Qtw100) were used as markers of high- and low-frequency performance fatigability, respectively. The MVIC, VA, Tw, Qtw100, and Qtw10:Qtw100 ratio decreased similarly from pre- to post-HIIE in both HIIE protocols (p < .05). The rating of perceived effort, blood pH, and plasma lactate responses were similar between HIIE protocols (p > .05), but the heart rate was higher in the longer HIIE protocol (p < .05). In conclusion, performance fatigability and its neural and muscular determinants seemed to be independent of the work and recovery durations of the HIIE, at least when HIIE protocols were matched for total work duration, work and recovery intensities, and density. Further, HIIE with long work and recovery might be preferable when the intention is to stress the chronotropic response.

Exercise induced Cognitive Function is an area needed in competitive fast ball sports that has stimulated interests of researchers due to its promising applicability in the field. It was noticed that although previous studies have suggested a role of exercise in facilitating cognitive performance, little is known regarding how to maximize these benefits. The study is undertaken to understand the effects of two types of aerobic training i.e., High Intensity Interval Exercise (HIIE) and Moderate Intensity Continuous Exercise (MCE) on executive function. For the assessment of cognition, after a four-week protocol, the Vienna Test System, a computerized assessment tool developed by Schuhfried GmbH (Moedling, Austria) is used for a defined universe of selected 20 athletes from various fast ball sports such as cricket, football, handball and volleyball. Statistical Analysis of Repeated Measured ANOVA along with post hoc test was done using SPSS version 21. Level of significance was kept at 5% with 95% study power. Collectively three variables, namely Sum of correct reactions, Sum of incorrect reactions and Sum of incorrect non-reactions; revealed improvement in attention, inhibitory function as well as executive function (p < 0.05). For fast ball athletes, the present study is suggestive of including MCE or HIIE programme in their training for 3 sessions/week; in order to optimize the improvement in cognitive level. The study can potentially guide every sports medicine team member, in order to develop an effective exercise protocol to improve the physiological as well as psychological capabilities of the athletes.

The purpose of this study is to investigate changes in gut microbiota related to metabolic diseases after moderate and high-intensity exercise. A total of 24 participants were divided into three groups: Non-Exercise Group (NEG, n = 8, 28.6 ± 5.3 years, 176.0 ± 7.8 cm, 81.3 ± 14.6 kg), Moderate Intensity Exercise Group (MIEG, n = 8, 26.5 ± 3.3 years, 176.9 ± 5.0 cm, 75.4 ± 9.5 kg), and Vigorous Intensity Exercise Group (VIEG, n = 8, 30.6 ± 5.9 years, 174.2 ± 3.5 cm, 77.8 ± 12.2 kg).

The participants were selected by assessing physical activity, gut health status, presence of diseases, recent disease diagnoses, and dietary disorders. Those who reported any presence disease or recent disease diagnosis were excluded from the current study. Stool samples were collected after a 10-h fast for gut microbiome analysis. MIEG participants trained at 40-59 % heart rate reserve (HRR) for at least 150 min per week, while VIEG participants trained at ≥ 60 % HRR for at least 90 min per week. After 4 weeks, all participants provided stool samples for gut microbiome analysis.Data analysis was conducted using the Wilcoxon test, with statistical significance set at ≤ 0.05.

The results indicated an increase in Prevotella in MIEG, while Veillonella, Dorea_formicigenerans, and Dorea_longicatena exhibited a decrease (p < 0.05). In VIEG, there was an increase in Bacteroides, Butyricimonas, Odoribacter, and Alistipes (p < 0.05).

These modified microbial groups were associated with factors related to metabolic diseases, including inflammatory bowel disease, obesity, colorectal cancer, diabetes, hypertension, metabolic liver diseases, and ischemic heart diseases. Additional research is essential to delve into the relationship between exercise and these alterations in the microbiome.

As a novel and time-efficient exercise form, high-intensity interval training (HIIT) has shown great potential in improving health-related physical fitness among diverse populations. However, empirical evidence on its efficacy among the elderly has not been well summarized. This systematic review and meta-analysis aimed to determine the effect of HIIT interventions on the parameters related to physical fitness and health of older adults, including resting heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), cardiorespiratory fitness (CRF), body mass index (BMI), body fat percent (BF%), waist circumference (WC), muscular endurance (ME), muscular strength (MS), muscular power (MP), balance and flexibility, compared to non-exercise and other-exercise (e.g., moderate-intensity continuous training, resistance training) conditions.

Literature published from January 2000 to May 2023 was collected through extensive searches across eight databases and relevant review papers. Randomized controlled trials (RCTs) featuring a minimum 2-week exercise intervention for older adults (≥ 60 years) were included. The pooled effect size of Hedges'g was estimated using random-effects models in R. Meta-regression was performed for both categorical (health status, duration of training programme, and frequency) and continuous moderators (mean age, male rate, and attrition rate).

Forty-four eligible RCTs with 1863 participants (52.1% female; 60.5-81.2 years) were included in the quantitative analysis. Compared to non-exercise condition, HIIT significantly improved resting HR (g = -0.36, 95%CI = [-0.67, -0.05], P = 0.032), SBP (g = -0.29, 95%CI = [-0.54, -0.03], P = 0.008), CRF (g = 0.77, 95%CI = [0.51, 1.04], P < 0.001), BF% (g = -0.26, 95%CI = [-0.41, -0.11], P = 0.006), MS (g = 0.47, 95%CI = [0.23, 0.71], P = 0.004), ME (g = 0.65, 95%CI = [0.10, 1.19], P = 0.036), and balance (e.g., timed-up-and-go) (g = -0.79, 95%CI = [-1.19, -0.40], P = 0.035). Compared to other-exercise condition, HIIT significantly improved resting HR (g = -0.11, 95%CI = [-0.21, -0.01], P = 0.029), SBP (g = -0.14, 95%CI = [-0.28, -0.01], P = 0.038), and CRF (g = 0.23, 95%CI = [0.07, 0.38], P = 0.008). No significant difference was found between HIIT and non-exercise condition for DBP, BMI and WC, as well as between HIIT and other-exercise condition for DBP, BMI, BF%, WC, ME, and balance (all P > 0.05). Meta-regression indicated that mean age moderated the HIIT effect on resting HR (b = -0.02, P = 0.014; HIIT vs. other-exercise condition) and SBP (b = 0.03, P = 0.048; HIIT vs. non-exercise), and attrition rate moderated the effect on CRF (b = 0.03, P = 0.007; HIIT vs. non-exercise).

This study supports the efficacy of HIIT in improving resting HR, SBP, CRF, BF%, MS, ME and balance among older adults. More empirical evidence is needed to determine the efficacy of HIIT for MP and flexibility in this population.

PROSPERO CRD42022316246.

Sutton, PJ, Mumford, PW, and Sunderland, KL. Workloads in collegiate women's lacrosse athletes during a Division II national championship season. J Strength Cond Res 38(9): 1651-1657, 2024-A comprehensive examination of the external and internal workloads in collegiate women's lacrosse athletes has yet to be reported. Thus, the primary purpose of this study was to determine the absolute and relative external and internal training and game workloads of National Collegiate Athletic Association (NCAA) Division II women's lacrosse athletes throughout an entire season. Data from 19 Division II women's lacrosse athletes were analyzed, encompassing each training session and game across an entire competitive season (February-May). External workloads were assessed using a wearable global positioning system, whereas internal workloads were determined through heart rate (HR) variables and session rating of perceived exertion. Game days were associated with significantly ( p < 0.05) greater absolute external and internal workloads. However, when comparing workloads relative to session duration, relative workloads between training and games were no longer significant ( p > 0.05) for total distance, high-speed running (≥15 km·h -1 ), HR-derived training impulse, or caloric expenditure. Nonetheless, relative sprint distance (>19 km·h -1 ) was significantly lower during games, whereas high-intensity accelerations (>2 m·s -2 ) and decelerations (<-2 m·s -2 ) were significantly greater during training compared with games ( p < 0.05). Practical applications of these findings suggest that coaches can better prepare athletes for game day conditions by adjusting training plans to replicate the duration and intensity of games. Overall, this comprehensive examination of internal and external workloads provides valuable data for coaches and practitioners to support performance comparisons, rehabilitation protocols, and workload analyses in collegiate women's lacrosse athletes.

Exercise is associated with changes in food consumption and cognitive function. The aim of this study was to examine the immediate effects of acute exercise on appetite, food choices, and cognitive processes, and the mediating role of cognitive functioning, namely inhibitory control, working memory, cognitive flexibility and decision making. We compared the effects of high-intensity interval exercise (HIIE) to a resting condition on appetite and food choices, using visual analogue rating scales and a computerised portion selection task. Mediation analysis was performed with exercise/rest condition as a predictor variable and cognitive measures were entered as mediating variables and food choice measures as outcomes. Young women with low activity levels, aged between 18 and 35 years with a body mass index (BMI) between 18 and 25 kg/m², were recruited. Participants (n = 30) demonstrated improved performance on a Stroop task following HIIE compared to the rest session, indicating enhanced attentional inhibition. Accuracy on an N-back task was significantly higher after HIIE, indicating an improvement in working memory and response times on the N-back task were shorter after HIIE, suggesting increased processing speed. Delay discounting for food (but not money) was reduced after HIEE but there were no significant effects on go/no-go task performance. On the trail-making task (a measure of cognitive flexibility), the time difference between trail B and A was significantly lower after HIIE, compared to rest. HIIE reduced rated enjoyment and ideal portion size selection for high energy dense foods. The relationship between exercise and food choices was mediated by inhibition as assessed by the Stoop task. These results suggest that HIIE leads to cognitive benefits and a reduced preference for high-calorie foods and that an enhancement of attentional inhibition may underlie this relationship.

Aims of the present investigation encompassed: (i) the quantification of training and match loads experienced by starters and non-starters within a professional soccer team; (ii) the identification of variations in these loads across different training modalities, namely, Preparation Training (PT), Match and Match Compensation Training (M&MCT), and their cumulative sum (Total Load; TL); and (iii) the formulation of guidelines aimed at harmonizing the weekly workloads between the groups.

Internal and external load of training sessions (n = 97), competitive matches (n = 21) and running based sessions (n = 4) were recorded for 21 weeks to investigate possible heterogeneity between starters and non-starters across PT, M&MCT and TL.

During PT, time spent in heart rate zone 5 (HRZ5) was increased for non-starters (+46.1%). During M&MCT, lower loads for non-starters were found in the rate of perceived exertion (sRPE) (-45.6%), HRZ4 (-54%) and HRZ5 (-77.8%), total distance (TD) (-37%), number of sprints (-58.1%), distance in speed zone 1 (-51.1%), zone 3 (-61.5%) and zone 4 (-59.8%) (SZ1, SZ3&4) and all acceleration and deceleration zones (Acc1-4; Dec1-4) (Acc1: -53.1%; Acc2: -56.3%; Acc3: -59.2%; Acc4: 57.8%) (Dec1: -45.9%; Dec2: -55.2%; Dec3: -63.2%; Dec4: -67.7%). Regarding TL, the non-starters' loads remain lower compared to starters for sRPE (-19.2%), HRZ4 (-21.6%) and HRZ5 (-41.4%), number of sprints (-26.7%), SZ3 (-34.2%), Acc3 (-24.4%), Acc4 (-26.1%), Dec2 (-18.7%), Dec3 (-24%) and Dec4 (-31.2%).

By implementing a running-based regimen on matchday and MCT the day after (MD+1), TD, distances in SZ1, SZ2, SZ4, SZ5, and counts of accelerations in Acc1&2, as well as Dec1, were effectively replicated for non-starters. All other variables remained unaligned for the non-starters. Given the prevalent emphasis on Small-Sided Games (SSGs) during MCT at MD+1, the incorporation of an additional running-based session for non-starters on MD is advised to address gaps in TD, sprint counts, and high-intensity load variables, such as HRZ4&5 and SZ 3 to 5.

Patients with schizophrenia suffer from physical health conditions, culminating in reduced physical functioning with enormous costs for patients and society. Although aerobic endurance and skeletal muscle strength, typically reduced in this population, relate to cognition and function, no study has explored their respective contributions to performance of functional skills and everyday tasks.

In a cross-sectional study, 48 outpatients (28/20 men/women; 35 ± 11(SD) years) with schizophrenia spectrum disorders (ICD-10; F20-25) were administered the UCSD Performance-based Skills Assessment-Brief (UPSA-B; functional skills), Specific Level of Functioning (SLOF; functional performance) and the Positive and Negative Syndrome (PANSS) scale. Peak oxygen uptake (V̇O2peak) was assessed along with leg press maximal muscle strength (1RM) and mechanical power.

UPSA-B performance was associated with V̇O2peak (r = 0.28,p < 0.05), accounting for 8 % (p < 0.05) of shared variance, but was unrelated to 1RM and mechanical power. The SLOF physical functioning domain was associated with V̇O2peak (r = 0.30,p < 0.05) and 1RM (r = 0.24,p < 0.05), while SLOF personal care (r = 0.27,p < 0.05) and activities (r = 0.30,p < 0.05) were related only to V̇O2peak. Hierarchical regression analyses revealed that while V̇O2peak and age combined to account for 20 % (p < 0.05) of the variance in physical functioning, the contribution of 1RM was eliminated after adjusting for age. V̇O2peak and negative symptoms combined predicted 24 % and 35 % of the variance in personal care and activities, respectively. UPSA-B scores did not add to the prediction of SLOF scores.

Although V̇O2peak and 1RM both relate to functional outcomes, the combination of V̇O2peak, age, and negative symptoms exert the greatest detrimental influence on functional performance beyond skills deficits.