American Journal of Clinical Nutrition, Vol 30, 1983-1993, Copyright © 1977 by The American Society for Clinical Nutrition, Inc

ORIGINAL RESEARCH COMMUNICATIONS

Effect of isometric exercises on body potassium and dietary protein requirements of young men

B Torun, NS Scrimshaw and VR Young

A diet supplying 0.5 or 1 g egg and milk protein/kg per day and adequate energy for maintenance of body weight was given to seven healthy men aged 18 to 21. After 2 weeks for adaptation to the diet they participated in 75 min of daily isometric exercises for 4 to 6 weeks. Two men on each protein intake continued to exercise for 4 to 5 additional weeks after undergoing changes in their daily protein intake from 0.5 to 1 g/kg or vice versa. A progressive decrease in total body potassium became significant by the fourth week of exercises in all men who began on the 0.5 g protein diet. Two men on that diet who remained as nonexercising controls lost no body K. These findings indicated that 0.5 g of egg and milk protein/kg per day was insufficient for men performing isometric exercises without prior training, whereas 1 g/kg per day appeared to be adequate. Two other nonexercising men on the 0.5 g diet who lost weight showed a marked negative nitrogen balance and loss of total body potassium which improved after their dietary energy intake increased. The changes in nitrogen balance and body weight observed in this investigation support the concept that protein requirements vary with energy intakes. Conversely, they suggest that energy requirements are influenced by the level of protein intake.

This article has been cited by other articles:

				W. M Rand, P. L Pellett, and V. R Young Meta-analysis of nitrogen balance studies for estimating protein requirements in healthy adults Am. J. Clinical Nutrition, January 1, 2003; 77(1): 109 - 127. [Abstract] [Full Text] [PDF]