A 4-week exercise and protein program improves muscle mass and physical functioning in older adults - A pilot study.

Background: Prehabilitation might attenuate common surgery-induced losses in muscle mass and physical performance. Beneficial effects of physical exercise with protein supplementation have been reported in older adults, but typically after an intervention of at least 12 weeks. The time-window for pre-surgery training is often limited to around 30 days, and it is not known if it is possible to achieve comparable results in such a short time window.

Objectives: The aim of this study was to pilot-test the effectiveness of a controlled four-week combined exercise and protein supplementation program on skeletal muscle-related outcomes in a Dutch older adult population.

Design: This study was a one-armed pilot trial.

Participants: Seventeen older men and women, aged 55-75y, not scheduled for surgery.

Intervention: A 4-week intervention program consisting of a twice-weekly supervised resistance and high-intensity aerobic exercise training of 75 min, combined with daily protein supplementation (2 doses of 15.5 g/day at breakfast and lunch).

Measurement: After two and four weeks, isometric quadriceps maximal voluntary contraction (MVC) was assessed via Biodex and quadriceps cross-sectional area (CSA) via magnetic resonance imaging. Other outcome measures were handgrip strength, chair rise time and maximal aerobic capacity (VO-max), as assessed from a submaximal exercise test.

Results: Compliance to the supervised training sessions (99.3%) and the protein supplementation (97%) was very high. The 4-week exercise and protein program led to an increase in quadriceps CSA of 2.3 ± 0.7 cm (P = 0.008) in the dominant leg and 3.2 ± 0.7 cm (P < 0.001) in the non-dominant leg. Isometric quadriceps MVC increased in the dominant leg (Δ14 ± 4 Nm, P = 0.001) and in the non-dominant leg (Δ17 ± 5 Nm, P = 0.003). Chair rise test time improved with -3.8 ± 0.5 s (P < 0.0001), and VO-max improved with 3.3 ± 1.1 ml/min/kg (P = 0.014). We observed no changes in body weight and handgrip strength.

Conclusion: A 4-week exercise and protein intervention led to improvements in muscle-related outcomes in older adults with low levels of physical activity.