CONCLUSIONS:Our data suggest that acute Cre supplementation improved the anaerobic performance of athletes and limited short-term oxidative insults, since Cre-induced iron overload was efficiently opposed by an increase in FRAP capacity. This increase can be attributed to an overproduction of uric acid (an end-product of purine metabolism and a powerful iron chelating agent) from energy-depleted muscles; and inherent antioxidant activity of Cre.Research shows that supplemental creatine (SC) can be used to enhance exercise performance. Most studies require a five day loading phase. However, little is known about the acute intake of SC and how it affects high intensity exercise greater than 30 seconds.
PURPOSE:The purpose of this study was to determine how an acute intake of SC impacted the ability to perform sprints lasting 30 seconds or more.METHODS: 20 subjects, 13 males & 7 female (age=22.5±2.9 yrs; ht=178.2±8.7 cm; wt = 79.3±12.2 kg) took part in two tests separated by at least 5 days. Each test consisted of 5 suicide sprints on a basketball court, separated by 2 min. One hour prior to testing, subjects drank either water (W) or a mixture of W and SC. After each sprint HR, RPE, and run time were recorded. Following last sprint subjects were asked if they felt performance was affected by the creatine. Creatine and magnesium have properties to counter inflammation; magnesium (Mg) is also a desensitizer of nociceptive pain. Research demonstrates conflicting effects of creatine on delayed onset muscle soreness (DOMS), an inflammatory process, with no reported effects of Mg on DOMS.PURPOSE: This study induced DOMS by eccentric activity, then supplemented subjects with placebo (P), magnesium-creatine (MgCr), or alkaline creatine (AlkCr), for four weeks to determine the efficacy of the supplementation on affecting DOMS. METHODS:Subjects were 36 young (18-24 years old), healthy, recreationally active individuals, randomly assigned to groups. Double blind supplementation was dextran (P), 5 g creatine, 400 mg (MgCr), and 5 g creatine plus soda ash (AlkCr) per day. Subjects kept 3-day diet records and physical activity logs pre and post treatment. They exercised on an electronic apparatus with foot pedals yielding force that was resisted eccentrically. Peak eccentric force was obtained at 35 cycles per minute. Subjects maintained 65% of the peak eccentric force, for five minutes of continuous work. They reported muscle soreness scores corresponding to a visual analog scale with scores from 1, normal to 10, very, very sore at 12, 24, 48, 60, and 72 hours post exercise. Repeated measures ANOVA was applied.
RESULTS:The creatine groups did have significant main effects of time in DOMS on a visual analog scale after 5 minutes of eccentric exercise (P<0.05). There were no significant effects between groups (P>0.05). Within group time effects were observed at 12, 24, and 36 hour intervals for AlkCr and at 12 hour intervals up to the 60 hours for MgCr, with DOMS scores lower following intervention. Pre intervention12-and 72-hour...
