Isolated knee extension resistance training and functional outcomes in patients with heart failure: A narrative review

Table 1 Isolated knee extensor resistance training protocol for heart failure patients

Ref.	Subject	Intensity	Session duration	Frequency, duration of exercise
Jankowska et al[26], 2008	10 stable CHF patients (NYHA III) with LVEF 30% ± 5%	35% of maximum strength in the first week, increasing gradually to 60% in the 12th week	± 30 minutes/session: 10 minutes warm-up, 10-15 minutes KERT, 5-10 minutes cool-down	3 times per week; program duration 12 weeks (training phase) + 12 weeks detraining
Louis et al[48], 2024	70 CHF patients (NYHA I-III) who participated in cardiac rehabilitation	30% 1RM at the start of training, progressively increased by 5%-10% every 4 sessions as tolerated	30-45 minutes/session: 10-15 minutes warm-up, 15-20 minutes core training (lower-limb resistance with KERT emphasis), 10-15 minutes cool-down	2 times per week; program duration 12 weeks
Jónsdóttir et al[28], 2006	43 CHF patients (NYHA II-III)	0%-25% 1RM in the initial phase, increasing to 35%-40% 1RM at the end of the study (in some patients)	± 45 minutes/session: 10 minutes warm-up, ± 35 minutes KERT core training, 5 minutes cool-down	2 times per week; program duration 5 months
Esposito et al[10], 2011	6 stable male CHF patients (NYHA II-III, VO2 peak Weber class C/B, LVEF 25% ± 3%) and 6 healthy male controls	Intensity varies, progressively increased based on evaluation every 2 weeks during KERT	± 50 minutes/session per leg: Knee extension exercises, including light warm-up and stretching	3 times per week; program duration 8 weeks
Hearon et al[11], 2022	12 HFpEF patients (> 65 years, EF > 50%) + 9 healthy controls	Individual, progressive intensity; initial steady-state, then 8 minutes × 2 minutes and 4 minutes × 4 minutes intervals, kick rate 30-50 kicks/minute	± 30 minutes/session per leg (total ± 60 minutes/session)	3 times per week; program duration 8 weeks
Magnusson et al[31], 1996	Eleven patients with chronic CHF (9 men, 2 women), NYHA II-IV, LVEF 5%-39%, some with idiopathic DCM, some post-MI, stable for ≥ 3 months. Randomized to single-leg strength training or single-leg endurance training	Strength training: Single-leg KERT, 80% of maximum. Endurance training: 65%-75% of peak single-leg workload, using a modified ergometer	Strength training: 4 sets of 6-10 repetitions, 2 minutes rest, 3 seconds of up-and-down movement. Endurance training: 15 minutes of dynamic knee extensor exercises	3 times per week, duration 8 weeks
Gordon et al[34], 1996	20 patients with stable CHF (NYHA II-III), LVEF 27% ± 3%, aged 43-73 years	65% of pretraining PWL at baseline, increasing to 75%	± 15 minutes per session: Two-legged dynamic knee extensor	3 times per week; program duration 8 weeks
Gordon et al[33], 1997	21 patients with stable CHF (NYHA II-III), LVEF 28% ± 3%, aged 43-73 years	One-legged KERT: 35% of absolute peak two-legged workload; two-legged KERT: 65%-75%	± 15 minutes per session: Dynamic knee extensor	3 times per week; program duration 8 weeks
Laoutaris et al[27], 2013	Stable CHF patients (NYHA II-III) with LVEF ≤ 40%, CHF due to ischemic or dilated cardiomyopathy, hemodynamically stable for ≥ 3 months	AT: 70%-80% maximal HR. RT: Dynamic KERT 50% 1RM, and upper limb resistance exercises using dumbbells of 1-2 kg, progressively every 2 weeks. BMI: 60% SPImax	AT: 20 minutes during the first week, increased by a minimum of 1 minutes in each training session. Combined ARI: AT: 30 minutes; RT: 3 sets of 10-12 repetitions KERT, 2 sets of 10-12 repetitions elbow flexion, shoulder flexion, and abduction; BMI: 20 minutes. Warm up and cooldown: 5 minutes each	3 times per week; program duration 12 weeks
Tyni-Lenné et al[12], 1996	16 stable CHF patients (NYHA II-III) with LVEF < 40%	During the first 4 weeks, 65%, and during the last 4 weeks, 75% of the absolute baseline PWL, bilateral dynamic KERT on a knee extensor ergometer	60 repeats per minute for 15 minutes. Warm-up: 6 minutes of walking and stretching, and a cooldown of 3 minutes of walking and stretching	3 times per week; program duration 8 weeks
Tyni-Lenné et al[36], 1998	24 stable CHF patients (NYHA II-III), 12 males & 12 females, LVEF < 40%	65% baseline PWL (weeks 1-4), 75% (weeks 5-8)	± 15 minutes/knee-extensor session + 6 minutes warm-up and 3 minutes cool-down	3 times per week; program duration 8 weeks

CHF: Chronic heart failure; NYHA: New York Heart Association; LVEF: Left ventricular ejection fraction; HFpEF, Heart failure with preserved ejection fraction; EF: Ejection fraction; DCM: Dilated cardiomyopathy; MI: Myocardial infarction; RM: Repetition maximum; KERT: Knee extension resistance training; PWL: Peak work load; AT: Aerobic training; HR: Heart rate; RT: Resistance training; BMI: Body mass index; SPImax: Sustained maximal inspiratory pressure; VO₂ peak: Peak oxygen uptake; ARI: Aerobic, resistance, and inspiratory muscle training.