The Effect of Oral Arginine During Energy Restriction in Male Weight Trainers

Abstract

ABSTRACT The hypothesis that oral arginine supplements increase growth hormone (GH) and influence body composition and muscle function was tested. Male weight trainers were divided into three groups of 6 each—control (Con), arginine supplemented (Arg), and placebo supplemented (Pla) and given a similar resistance exercise prescription. Con consumed food ad libitum throughout the experiment. Arg and Pla consumed a hypocaloric diet for 10 days following 1 week of a weight maintenance diet and were given supplements for each of those 10 days. Measurements made on Arg and Pla included hydrostatic weighing, nitrogen balance, resting IGF-1, and response of serum GH and arginine to supplement ingestion. Both groups reduced weight and body fat but maintained fat-free mass during the hypocaloric phase. They demonstrated a significant decrease in peak torque for the biceps and quadriceps. Neither supplement acutely affected serum GH or arginine over the 90 min after ingestion, nor resting IGF-1. There was no significant difference between groups in nitrogen balance. Thus the supplement had no influence on weight loss, fat or lean tissue loss, muscle function, or overall GH status.