Studies on Creatine, Strength, Adverse Events
NATICK, Mass.--Researchers from the U.S. Army Research Institute of Environmental Medicine reported that creatine may have an effect on strength and endurance. In a study appearing in November's The Journal of Strength and Conditioning Research (16, 4:500-8, 2002) (http://nsca.allenpress.com), researchers led by John Warber determined the effects of creatine supplementation on performance during military training tasks. Two groups of 13 male soldiers each performed three consecutive military obstacle courses separated by five days; soldiers also completed a rifle marksmanship task on three occasions and completed a bench press consisting of five sets to failure. Supplementation of either placebo or creatine, delivered via sports bars, was given, with the creatine group given up to 24 g/d of creatine.
Creatine usage resulted in a significant increase (14 percent) in bench press repetitions, but no difference was seen between groups in terms of course run times. Neither marksmanship nor mood was affected by creatine. Those on creatine had an average increase of 1.4 kg in body mass and a .5-percent decrease in body fat percentage.
It also appears that creatine has no long-term adverse effects on the kidney or liver. In a study appearing in the December International Journal of Sport Nutrition and Exercise Metabolism (12, 4:453-60, 2002) (www.humankinetics.com), researchers from Truman State University, Kirksville, Mo., investigated the effects of 5 g/d to 20 g/d over .25 to 5.6 years in 23 college football players. When noting serum creatinine, researchers reported that levels were not significantly different between groups.