Β-Alanine Lab Report
Purpose: To examine the effects of increased muscle carnosine concentrations, achieved via chronic β-alanine (BA) supplementation, on muscle contractile properties before and after muscle specific fatigue. Methods: Twenty-three men completed a familiarisation session followed by two experimental sessions, pre- and post-28 days supplementation with 6.4 g/day of β-alanine (n=12) or placebo (n=11). During each session, force was twice recorded during a series of knee extensor contractions: resting and potentiated twitches and octet (8 pulses, 300 Hz) contractions elicited via femoral nerve stimulation, percutaneous contraction (1-100 Hz, 1 s) evoked via superficial muscle stimulation and maximum voluntary contractions, both before and after knee
extensor fatiguing exercise (IKET). Results: BA supplementation did not affect the force frequency relationship before or after the muscle specific fatiguing exercise. Similarly, force responses at 25 and 50 ms as well as peak force of resting and potentiated twitch and octet contractions before and after muscle specific fatigue were all unaffected by BA supplementation (all P > 0.05). Time-to-peak tension of resting and potentiated twitches was unaffected by supplementation however half-relaxation time was reduced by 8% (P = 0.045) and 22% (P = 0.027) before and after muscle specific fatigue, respectively. Maximum voluntary force was unaffected by BA supplementation. Conclusions:
extensor fatiguing exercise (IKET). Results: BA supplementation did not affect the force frequency relationship before or after the muscle specific fatiguing exercise. Similarly, force responses at 25 and 50 ms as well as peak force of resting and potentiated twitch and octet contractions before and after muscle specific fatigue were all unaffected by BA supplementation (all P > 0.05). Time-to-peak tension of resting and potentiated twitches was unaffected by supplementation however half-relaxation time was reduced by 8% (P = 0.045) and 22% (P = 0.027) before and after muscle specific fatigue, respectively. Maximum voluntary force was unaffected by BA supplementation. Conclusions: