Does Creatine Supplementation Reduce Lengthening Contraction Induced Muscle Damage?

Creatine supplementation (Cr+) is known to increase recovery between exercise bouts and may increase force production capabilities of skeletal muscle. Heat shock proteins (Hsps), are up-regulated in skeletal muscle following damage, particularly following lengthening contractions (LC). Two experiments were conducted to examine the effect of Cr supplementation (Cr+; 14 days @ 300mg/kg) on skeletal muscle damage following 15 and 25 LCs. In each the left tibilais anterior (TA) of (n=6) Cr+ and Cr- Sprague-Dawley rats underwent LCs (either 15 or 25). No significant differences in TA Hsp content were observed between Cr- and Cr+ animals following 25 LCs, with both showing elevated Hsp72 and 25 content. Fifteen LCs also significantly increased Hsp72 content in both groups, but Hsp25 was significantly elevated only in Cr- animals. In summary, Cr supplementation did not significantly reduce LC induced muscle damage. However, it remains possible that Cr supplementation may reduce stress following 15 LCs.M.Sc