Oral amino-acid provision does not affect muscle strength or size gains in older men

Purpose: The intent of this investigation was to examine the effects of a daily oral provision consisting of amino acids (L-lysine. L-leucine. L-valine. L-phenylalanine, L-threonine, L-histidine, L isoleucine, and L-methionine) in combination with carbohydrates (dextrose. sucrose. and fructose) on whole muscle strength and size characteristics during a 12-wk progressive knee extensor resistance training (PRT) pro-ram in older men (>65 yr). Methods: Seventeen older men were randomly assigned to either the experimental (EX) or control (CN) groups, The EX (N = 8) and CN (N 9) groups had the following characteristics-EX: 70.8 +/- 1.5 yr, 91,0 +/- 4.9 kg, and 177.0 +/- 3.9 cm: CN: 72.1 +/- 1.9 yr, 75.4 +/- 4.7 kg. and 176.1 +/- 3.0. Pre and post PRT maximal unilateral isometric torque (N.m), isokinetic torque (1.05, 1.57, 2,09, 3,14, 4.19. and 5.24 rad.s(-1)). work capacity (30 consecutive reps at 3.14 rad.s(-1)) torque, one repetition maximum (1RM) bilateral isotonic strength, and whole muscle cross-sectional area (CSA) of the mid-thigh Acre performed by computed tomography on each subject. Results: All variables showed and improvement with training (P < 0.05): however, there were no differences between the groups, Both groups increased in isometric strength by 21%, and isokinetic torque by 24% to 11% with the varying velocities ( 1.05-5.24 rad.s(-1)). Whole muscle 1RM strength and thigh CSA increased 50% and 6.5%, respectively. Additionally, voluntary torque/CSA increased 12% in both the EX and CN groups (P < 0.05). Conclusions: In conclusion. these data suggest that whole muscle strength and size are not enhanced with a postexercise daily provision of an oral amino-acid complex during 12 wk of PRT in older men.