Effects of resistance training and chromium picolinate on body compositionand skeletal muscle in older men

The effects of chromium picolinate (CrPic) supplementation and resistance t raining (RT) on skeletal muscle size, strength, and power and whole body co mposition were examined in 18 men (age range 56-69 yr). The men were random ly assigned (double-blind) to groups (n = 9) that consumed either 17.8 mu m ol Cr/day (924 mu g Cr/day) as CrPic or a low-Cr placebo for 12 wk while pa rticipating twice weekly in a high-intensity RT program. CrPic increased ur inary Cr excretion similar to 50-fold (P < 0.001). RT-induced increases in muscle strength (P < 0.001) were not enhanced by CrPic. Arm-pull muscle pow er increased with RT at 20% (P = 0.016) but not at 40, 60, or 80% of the on e repetition maximum, independent of CrPic. Knee-extension muscle power inc reased with RT at 20, 40, and 60% (P < 0.001) but not at 80% of one repetit ion maximum, and the placebo group gained more muscle power than did the Cr Pic group (RT by supplemental interaction, P < 0.05). Fat-free mass (P < 0. 001), whole body muscle mass (P < 0.001), and vastus lateralis type II fibe r area (P < 0.05) increased with RT in these body-weight-stable men, indepe ndent of CrPic. In conclusion, high-dose CrPic supplementation did not enha nce muscle size, strength, or power development or lean body mass accretion in older men during a RT program, which had significant, independent effec ts on these measurements.