Objective: To investigate the effect of physical training (PTr) on upper leg muscle area, muscle strength and muscle endurance expressed as upper leg muscle function (ULMF) in relation to exercise performance in CHF.
Design: Randomised to a training (TG) or control group (CG).
Setting: Outpatient cardiac rehabilitation centre of community hospital.
Patients: 77 CHF patients (59 men and 18 women), NYHA class II/III, age 59.8+/-9.3 years, LVEF 27+/-8%. Sixteen patients dropped out during the intervention period, 61 patients (M/F:46/15) completed the study.
Intervention: PTr (combined strength and endurance exercises) four times per week, twice supervised and twice at home, during 26 weeks.
Main outcome measures: LVEF, body composition, daily physical activity, exercise performance, upper leg muscle area and isokinetic leg muscle variables.
Results: Workload and peak oxygen consumption decreased in the CG (-4.1% and -4%) but increased in the TG (+5% and +4%) following PTr (p<0.05, ANOVA repeated measures). Hamstrings area decreased in the CG and did not change in the TG (p<0.05, ANOVA repeated measures). ULMF improved in the TG, but remained unchanged in the CG (+13.0% and 0.0, respectively, p<0.05; ANOVA repeated measures). At baseline and after intervention nearly 60% of the variance in maximal workload was explained by ULMF and quadriceps muscle area (multiple regression analysis).
Conclusions: In CHF patients, home-based training in conjunction with a supervised strength and endurance training program is safe, feasible and effective and does not require complex training equipment. Physical training prevented loss of hamstrings muscle mass and improved exercise performance by enhancing muscle strength and endurance.