Effects of exercise and whey protein on muscle mass, fat mass, myoelectrical muscle fatigue and health-related quality of life in older adults: a secondary analysis of the Liverpool Hope University-Sarcopenia Ageing Trial (LHU-SAT).

PURPOSE

To investigate the effects of exercise in combination with, or without, a leucine-enriched whey protein supplement on muscle mass, fat mass, myoelectrical muscle fatigue and health-related quality of life (QOL) in older adults.

METHODS

100 community-dwelling older adults [52% women, age: 69 ± 6 years (mean ± SD)] were randomised to four [Control (C); Exercise (E); Exercise + Protein (EP); Protein (P)] independent groups. E and EP groups completed 16 weeks of exercise [resistance (2 times/week) and functional (1 time/week]. EP and P groups were also administered a leucine-enriched whey protein supplement (3 times/day) based on body weight (1.5 g/kg/day). Muscle and fat mass (bioelectrical impedance analysis), myoelectrical muscle fatigue (surface electromyography) and QOL (WHOQOL-BREF) were measured pre- and post-intervention.

RESULTS

At post-intervention, the rectus femoris (E: - 4.8%/min, p = 0.007, ES = 0.86; EP: - 3.3%/min, p = 0.045, ES = 0.58) and bicep femoris (E: - 3.9%/min, p < 0.001, ES = 1.46; EP: - 4.3%/min, p < 0.001, ES = 1.58) muscles became more resistant to fatigue in the E and EP groups, respectively (p < 0.05 versus C). QOL improved in the E group only. Muscle and fat mass did not change (p > 0.05).

CONCLUSION

Physical exercise is a potent method to improve myoelectrical muscle fatigue and QOL in older adults. However, leucine-enriched whey protein did not augment this response in those already consuming sufficient quantities of protein at trial enrolment.