Volek et al. (1999) found after 12 weeks of resistance training in men, Cr supplementation increased muscle fiber diameter in both Type 1 and Type 2 muscle fibers by 35% (Fig. 3). Resistance-trained subjects not supplemented with Cr had fiber-type increases of 6 to 15%. Subjects both trained and supplemented had fat-free mass increases of 1.5 kg after 1 week and 4.3 kg after 12 weeks compared with the trained-only group that had a fat-free mass increase of 2.1 kg after 12 weeks.