Protein supplement twice daily ups strength, lean mass in older men
Protein-based, multi-ingredient nutritional supplements, consumed twice daily, increase lean mass and muscle strength in older males, a new trial has found.
The study included 49 healthy elderly males (mean age 73±1 years; mean body mass index, 28.5±1.5 kg/m2) randomized to receive either the nutritional supplement (n=25) or a control drink (n=24). Participants received supplements or controls alone for the first 6 weeks (phase 1) and underwent an added exercise training for the next 6 weeks (phase 2).
In phase 1, the supplement group showed a 3-percent increase in the sum of all one repetition maximums (1RM) from 206±7kg at baseline to 212±8 kg after 6 weeks (p<0.001). Isotonic muscle strength increased a further 20 percent after phase 2 (p<0.001).
After phase 1, the supplement group showed significant increases in whole-body (0.7 kg; p<0.001), appendicular (0.4 kg; p<0.01), leg (0.3 kg; p<0.01) and trunk (0.4 kg; p=0.002) lean mass. No further increases were observed after phase 2.
No significant changes in strength in the control group was observed during phase 1. Sum of all 1RMs increased by 21 percent (p<0.001) after phase 2. The observed changes in lean body mass in either phase were nonsignificant.
The nutritional supplement used contained whey protein, calcium, omega-3 polyunsaturated fatty acids, creatinine and vitamin D. Control drinks had maltodextrin. Supplements or controls were taken twice daily for 20 weeks.
The exercise regimen consisted of resistance exercise training twice weekly and high-intensity interval training once weekly. Dual-energy x-ray absorptiometry was used to measure body composition.