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The systematic review presented here assessed the effects of energy restriction (ER) and exercise (EX) on fat-free mass (FFM) in overweight and obese middle-aged and older adults. PubMed was searched using the key words 'weight loss or energy restriction' AND 'skeletal muscle or body composition,' with limitations set for 'human' and 'middle-aged and aged.' Results from 52 studies are reported as the percentages of EX (mainly aerobic training), ER, or ER+EX groups that had a specified change in body weight and FFM, since insufficient data were available for a meta-analysis. The EX groups had modest body weight and FFM changes. Eighty-one percent and 39% of the ER and ER+EX groups, respectively, lost [greater than or equal to] 15% of body weight as FFM. These findings suggest that exercise is an effective tool to help men and postmenopausal women aged [greater than or equal to] 50 years, with a BMI greater than 25 kg/[m.sup.2]preserve FFM after moderate ER-induced weight loss, which is important for combating sarcopenic obesity. Key words: aging, body composition, exercise, muscle loss, weight loss doi: 10.1111/j.1753-4887.2010.00298.x

Little is known about the effects of different quantities of whey protein on exercise training-induced changes in body composition and indices of metabolic syndrome in middle-aged overweight and obese adults. Therefore, we examined the effects of consuming 0.8-MJ supplements with 0 (n = 126), 10 (n = 112), 20 (n = 44), or 30 (n = 45) g whey protein twice daily in conjunction with resistance (2 d/wk) and aerobic (1 d/wk) exercise training in a double-blind, randomized, placebo-controlled, community-based 9-mo study in men (n= 117) and women (n = 210); (age: 48 ± 7.9 y; BMI: 30.0 ± 2.8 kg/m2). Whey protein supplementation did not influence any of the following outcomes, some of which were affected by training. Among all participants, strength increased by 15 ± 12% (P < 0.001) and maximal oxygen uptake capacity (V02max) increased by 9 ± 15% (P< 0.001). Body weight was unchanged (0.1 ± 3.7 kg, P = 0.80), lean body mass increased by 1.9 ± 2.8% (0.95 ± 1.3 kg, P < 0.001 ), and fat mass decreased by 2.6 ± 9.4% (-0.86 ±3.1 kg, P = 0.001 ). Oral-glucose-tolerance testing showed that plasma glucose AUC was unchanged (-18.0 ± 170 mmol/L ·3 h, P = 0.16), insulin AUC decreased by 2.6 ± 32% (-7.5 ± 29 nmol/L · 3 h, P = 0.01 ), and HOMA-IR (0.2 ± 2.0, P = 0.81 ) and the insulin sensitivity index (0.3 ± 3.0, P = 0.63) were unchanged. Plasma concentrations of TG; total, LDL, and HDL cholesterol; C-reactive protein; plasminogen activator inhibitor-1; blood pressure: and waist circumference were unchanged. Whey protein supplementation did not affect exercise training-induced responses in body composition and indices of metabolic syndrome in middle-aged overweight and obese adults who maintained body weight [ABSTRACT FROM AUTHOR]

Evidence suggests that consumption of over-the-counter cyclooxygenase (COX) inhibitors may interfere with the positive effects that resistance exercise training has on reversing sarcopenia in older adults. This study examined the influence of acetaminophen or ibuprofen consumption on muscle mass and strength during 12 wk of knee extensor progressive resistance exercise training in older adults. Thirty-six individuals were randomly assigned to one of three groups and consumed the COX-inhibiting drugs in double-blind placebo-controlled fashion: placebo (67 ± 2 yr; n = 12), acetaminophen (64 ± 1 yr; n = 11; 4 g/day), and ibuprofen (64 ± 1 yr; n = 13; 1.2 g/day). Compliance with the resistance training program (100%) and drug consumption (via digital video observation, 94%), and resistance training intensity were similar (P > 0.05) for all three groups. Drug consumption unexpectedly increased muscle volume (acetaminophen: 109 ± 14 cm(3), 12.5%; ibuprofen: 84 ± 10 cm(3), 10.9%) and muscle strength (acetaminophen: 19 ± 2 kg; ibuprofen: 19 ± 2 kg) to a greater extent (P < 0.05) than placebo (muscle volume: 69 ± 12 cm(3), 8.6%; muscle strength: 15 ± 2 kg), when controlling for initial muscle size and strength. Follow-up analysis of muscle biopsies taken from the vastus lateralis before and after training showed muscle protein content, muscle water content, and myosin heavy chain distribution were not influenced (P > 0.05) by drug consumption. Similarly, muscle content of the two known enzymes potentially targeted by the drugs, COX-1 and -2, was not influenced (P > 0.05) by drug consumption, although resistance training did result in a drug-independent increase in COX-1 (32 ± 8%; P < 0.05). Drug consumption did not influence the size of the nonresistance-trained hamstring muscles (P > 0.05). Over-the-counter doses of acetaminophen or ibuprofen, when consumed in combination with resistance training, do not inhibit and appear to enhance muscle hypertrophy and strength gains in older adults. The present findings coupled with previous short-term exercise studies provide convincing evidence that the COX pathway(s) are involved in the regulation of muscle protein turnover and muscle mass in humans.