Four-Month Course of Soluble Milk Proteins Interacts With Exercise to Improve Muscle Strength and Delay Fatigue in Elderly Participants

作者：Gryson Celine; Ratel Sebastien; Rance Melanie; Penando Stephane; Bonhomme Cecile; Le Ruyet Pascale; Duclos Martine; Boirie Yves; Walrand Stephane^*

来源：Journal of the American Medical Directors Association, 2014, 15(12): 958.e1-958.e9.

DOI：10.1016/j.jamda.2014.09.011

• Soluble milk proteins rich in leucine
• exercise
• older people
• muscle strength
• muscle fatigue

Background: The benefit of protein supplementation on the adaptive response of muscle to exercise training in older people is controversial. %26lt;br%26gt;Objective: To investigate the independent and combined effects of a multicomponent exercise program with and without a milk-based nutritional supplement on muscle strength and mass, lower-extremity fatigue, and metabolic markers. %26lt;br%26gt;Design: A sample of 48 healthy sedentary men aged 60.8 +/- 0.4 years were randomly assigned to a 16-week multicomponent exercise training program with a milk-based supplement containing, besides proteins [total milk proteins 4 or 10 g/day or soluble milk proteins rich in leucine (PRO) 10 g/day], carbohydrates and fat. Body composition, muscle mass and strength, and time to task failure, an index of muscle fatigue, were measured. Blood lipid, fibrinogen, creatine phosphokinase, glucose, insulin, C-reactive protein, interleukin-6, tumor necrosis factor-alpha soluble receptors, and endothelial markers were assessed. %26lt;br%26gt;Results: Body fat mass was reduced after the 4-month training program in groups receiving 10 g/day of protein supplementation (P %26lt; .01). The training program sustained with the daily 10 g/day PRO was associated with a significant increase in dominant fat free mass (+5.4%, P %26lt; .01) and in appendicular muscle mass (+4.5%, P %26lt; .01). Blood cholesterol was decreased in the trained group receiving 10 g/day PRO. The index of insulin resistance (homeostasis model assessment-insulin resistance) and blood creatine phosphokinase were reduced in the groups receiving 10 g/day PRO, irrespective of exercise. The inflammatory and endothelial markers were not different between the groups. Training caused a significant improvement (+10.6% to 19.4%, P %26lt; .01) in the maximal oxygen uptake. Increased maximum voluntary contraction force was seen in the trained groups receiving 10 g/day of proteins (about 3%, P %26lt; .05). Time to task failure was improved in the trained participants receiving a 10 g/day supplementation with PRO (P %26lt; .01). %26lt;br%26gt;Conclusions: Soluble milk proteins rich in leucine improved time to muscle failure and increase in skeletal muscle mass and strength after prolonged multicomponent exercise training in healthy older men.

• 出版日期2014-12