Mg2+-Creatine Chelate and a Low-Dose Creatine Supplementation Regimen Improve Exercise Performance

Abstract

We tested the hypotheses that, compared with a placebo group or creatine (Cr) group, a Mg(2+)-Cr chelate group would demonstrate improvements in the 1 repetition maximum (1RM) on the bench press and be able to perform more work at 70% of the 1RM for the bench press. Thirty-one weight-trained men were randomly assigned in a double-blind manner to a placebo group (multidextran), a Cr group (2.5 g of Cr daily), or a Mg(2+)-Cr group (2.5 g of Cr daily). Baseline data were collected for the bench press 1RM and maximal work completed during a fatigue set at 70% of the 1RM. Following 10 days of Cr supplementation, follow-up tests were completed for the dependent variables. Groups were similar when the change in 1RM was evaluated either absolutely or relatively. Both the Cr and the Mg(2+)-Cr groups had significantly larger increases in work, both absolutely and relatively, when compared with the placebo group. Partial support for the hypothesis suggests that low doses of Cr are effective at increasing fiber Cr content, and consequently, performance. Further, the Cr and Mg(2+)-Cr groups were similar in both performance tests, suggesting that the proposed mechanism of entry is no better than the conventional method when 2.5 g of Cr is administered and performance is measured as work. This study raises the possibility that a low dose of Cr may be an effective means of enhancing performance after short-term ingestion.