High-intensity interval training for health benefits and care of cardiac diseases - The key to an efficient exercise protocol

Table 1 Variables improved by high-intensity interval training

Variables	Target
Skeletal muscle biopsy
PGC-1α
Mitochondrial function in lateral vastus	O2 consumption
Fatty acid transporter in the vastus lateralis and FAS (a key lipogenic enzyme)
IR β subunit in skeletal muscle (peripheral insulin sensitivity)	Metabolic
Re-uptake of Ca2+ into the salcoplasmic reticulum
Physiological test
Exercise test
Improvement of ventilatory efficiency (increased value of PETCO2)	Respiratory function
Oxygen consumption at the first ventilator threshold	Cardiac function
Oxygen pulse	Cardiac function
Parasympathetic activity (HR recovery)	Autonomic function
Duration of exercise time	Autonomic function
Distance walked during the 6-min walk	Work capacity
Ultrasonography
Cardiac function
Reversed LV re-modelling (LV end diastolic and systolic volumes)	Cardiac function
Ea
Diastolic function (e′, E, E/ e′, E/A ratio, higher proportion of e′ > 8 cm/s, E improvement during exercise),
Systolic function after 12 wk at rest and during exercise)
E reduction
Deceleration time increase
Left atrial volume
Reduced-plasma BNP
Vascular
Endothelial dysfunction (FMD)	Vascular function
Coronary plaque necrotic core reduction in defined coronary segments	Vascular function
Laboratory test
Myeloperoxidase	Anti-oxidant
High sensitivity CRP	Inflammation
Interleukin-6
insulin sensitivity (HOMA index)	Metabolic
HbA1C
Clinico-social data
Increased Short Form-36 physical/mental component scores and decreased Minnesota Living with Heart Failure questionnaire score	Quality of life
Frequency of metabolic syndrome	Risk factor

HOMA: Homoestasis model assessment; IR: Insulin receptor; PGC: Peroxisome-proliferator activated receptor γcoactivator; FMD: Flow mediated dilation; FAS: Fatty acid synthase; PETCO₂: End-tidal carbon dioxide; HR: Heart rate; LV: Left ventricular; BNP: Brain natriuretic peptide.