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Gryson C.,French National Institute for Agricultural Research | Ratel S.,University Blaise Pascal | Rance M.,University Blaise Pascal | Penando S.,Estaing University Hospital Center | And 5 more authors.
Journal of the American Medical Directors Association | Year: 2014

BACKGROUND: The benefit of protein supplementation on the adaptive response of muscle to exercise training in older people is controversial.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.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-α soluble receptors, and endothelial markers were assessed.RESULTS: Body fat mass was reduced after the 4-month training program in groups receiving 10 g/day of protein supplementation (P < .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 < .01) and in appendicular muscle mass (+4.5%, P < .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 < .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 < .05). Time to task failure was improved in the trained participants receiving a 10 g/day supplementation with PRO (P < .01).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. Copyright © 2014 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved. Source


Gryson C.,French National Institute for Agricultural Research | Gryson C.,Clermont University | Ratel S.,University Blaise Pascal | Rance M.,University Blaise Pascal | And 9 more authors.
Journal of the American Medical Directors Association | Year: 2014

Background: The benefit of protein supplementation on the adaptive response of muscle to exercise training in older people is controversial. 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. Design: A sample of 48 healthy sedentary men aged 60.8±0.4years were randomly assigned to a 16-week multicomponent exercise training program with a milk-based supplement containing, besides proteins [total milk proteins 4 or 10g/day or soluble milk proteins rich in leucine (PRO) 10g/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-α soluble receptors, and endothelial markers were assessed. Results: Body fat mass was reduced after the 4-month training program in groups receiving 10g/day of protein supplementation (. P<.01). The training program sustained with the daily 10g/day PRO was associated with a significant increase in dominant fat free mass (+5.4%, P<.01) and in appendicular muscle mass (+4.5%, P<.01). Blood cholesterol was decreased in the trained group receiving 10g/day PRO. The index of insulin resistance (homeostasis model assessment-insulin resistance) and blood creatine phosphokinase were reduced in the groups receiving 10g/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<.01) in the maximal oxygen uptake. Increased maximum voluntary contraction force was seen in the trained groups receiving 10g/day of proteins (about 3%, P<.05). Time to task failure was improved in the trained participants receiving a 10g/day supplementation with PRO (. P<.01). 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. © 2014 AMDA - The Society for Post-Acute and Long-Term Care Medicine. Source


Ratel S.,University Blaise Pascal | Gryson C.,French National Institute for Agricultural Research | Rance M.,University Blaise Pascal | Penando S.,Estaing University Hospital Center | And 7 more authors.
Applied Physiology, Nutrition and Metabolism | Year: 2012

The aim of the present study was to investigate the effects of a 8-week detraining period after a 16-week multicomponent training program including strength and aerobic exercises on the main determinants of aerobic fitness, muscle strength and some metabolic markers in 24 older subjects (60.2 ± 3.0 years). The oxygen uptake at the second ventilatory threshold (VO 2V T2) and at the end of exercise (VO 2max), maximum voluntary contraction force (MVC) of knee extensors and some metabolic indexes, i.e., insulin sensitivity, blood lipid profile, inflammatory cytokines, and endothelial function, were evaluated at baseline and after the training and detraining periods. The training program induced significant improvements in VO 2V T2 (16%, p < 0.05), VO 2max (14%, p < 0.05), MVC (6.5%, p < 0.05), insulin sensitivity (16%, p < 0.05), and endothelial function (p < 0.05) but induced no significant change in lipid profile and inflammatory cytokines. Interestingly, VO 2V T2 and VO 2max (mL·min -1·kg -1) scores remained significantly above pretraining values after the 8-week detraining period. However, the detraining period reversed MVC values, the insulin sensitivity and endothelial function to baseline levels. To conclude, the 8-week detraining partially reversed the major components of aerobic fitness but totally abolished the gains in muscle strength and some metabolic indexes after a 16-week multicomponent training program in older men. Taken as a whole, the results of this study emphasize the importance of exercise prescriptions for older subjects and the need not to interrupt exercise-training over a prolonged period. Source


Rulliere C.,Montpellier University | Perenes L.,Lactalis Research and Development | Senocq D.,Lactalis Research and Development | Dodi A.,French Atomic Energy Commission | Marchesseau S.,Montpellier University
Food Chemistry | Year: 2012

Polyphosphate blends are used in food such as meat and dairy products to improve their texture and stability by sequestering metal ions. This study aims to analyse the impact of high temperature treatments on the composition of polyphosphates with regards to phosphate chain length in aqueous solutions with or without calcium. Temperature treatments of 120°C for 10 min led to the hydrolytic degradation of long-chain phosphates into orthophosphate and trimetaphosphate whereas heating the salts to 100°C in aqueous solutions had little effect on their composition. The presence of calcium increased the hydrolysis rate of long-chain phosphates and led to more trimetaphosphate and pyrophosphate as end products. The evolution of emulsifying salts' composition under heat treatment may lead to a modification of their chelating properties since short-chain phosphates are less efficient to chelate calcium than long-chain phosphates. © 2012 Elsevier Ltd. All rights reserved. Source

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