Presidential Closing Remarks 12:05 PM – 12:15 PM: Immediately Following President's Lectures ROOM: Ballroom 2/3 and Ballroom 1: G-41 Free Communication/Slide – Supplements: SATURDAY, JUNE 3, 2006 9:00 AM – 11:00 AM ROOM: 612
Creatine supplementation is associated with decreased incidence of muscle injuries, and athletes report enhanced recovery while ingesting creatine during resistance training. Previous clinical trials have shown that creatine supplementation reduces muscle damage and inflammation following running, but not following high-force eccentric exercise. Potentially, the strain placed on muscle fibers from high-force eccentric exercise is too overwhelming for creatine to exert any protective effect. However, creatine supplementation may exert protective effects on skeletal muscle stressed by a resistance training test more typical of what athletes experience in their daily training.
PURPOSE: To examine the effects of oral creatine supplementation (0.3 g/kg of body mass/d × 5 d followed by 0.03 g/kg of body mass/d × 5 d) on markers of exercise stress (i.e. muscle serum protein activity, maximal strength, range of motion, muscle soreness) to determine if creatine supplementation offers protective effects on skeletal muscle following resistance exercise.
METHODS: Twenty-three weight-trained males (19–27 yrs) ingested either creatine (Cr) or a placebo (P) for 10 d. Following 5 d of supplementation, subjects performed a squat exercise protocol (5 sets of 15–20 repetitions at 50% of 1-RM). Assessments of creatine kinase (CK) and lactate dehydrogenase (LDH) activity, maximal strength, range of motion (ROM), and muscle soreness (SOR) with movement and palpation were conducted pre-exercise, post-exercise, and during a 5 d follow up period.
RESULTS: There were no differences in age (Cr: 22.1 yr, P: 22.2 yr), body mass (Cr: 88.4 kg, P: 83.4 kg), maximal strength (Cr: 137.8 kg, P: 126.1 kg), or years of training experience (Cr: 6.4 yr, P: 5.8 yr) between groups prior to supplementation. Creatine and placebo-supplemented subjects experienced significant decreases in maximal strength (Cr: 13.4 kg, P: 17.5 kg; p<0.001) and ROM (Cr: 2.4°, P: 3.0°; p<0.001) immediately post-exercise, with no difference between groups. Following the exercise test, there were significant increases in SOR with movement (peak soreness: Cr: 43 mm, P: 46 mm) (p<0.05 at 24, 48, and 72 hrs post-exercise), SOR with palpation (peak soreness: Cr: 37 mm, P: 34 mm) (p<0.05 at 24, 48, and 72 hrs post-exercise), and CK activity (peak CK: Cr: 1214 IU/L, P: 1132 IU/L) (p<0.05 at 24 and 48 hrs post-exercise), with no differences between groups at any time.
CONCLUSION: Creatine supplementation does not reduce skeletal muscle damage or enhance recovery following resistance exercise.
Supported by Bloomsburg University, the National Strength and Conditioning Association, and the Gatorade Sports Science Institute