Forskning

September 4, 2015

Muscle pain as a regulator of cycling intensity: effect of caffeine ingestion

A R Gonglach et al, 2015, Muscle pain as a regulator of cycling intensity: effect of caffeine ingestion, Medicine and Science in Sports and Exercise, published online ahead of print.

ABSTRACT:
Caffeine ingestion improves endurance time-trial performance. However, the ergogenic mechanism of action remains unresolved. One potential explanation for caffeine’s performance enhancing effect is an improvement in work for a given amount of muscle pain.

PURPOSE: To test this hypothesis, participants performed two studies in which they regulated exercise intensity based upon feelings of muscle pain.

METHODS: Thirteen young men were asked to regulate exercise intensity based on feelings of “moderate” muscle pain (a “3” on a 0-10 pain scale). After 3 familiarization trials, either caffeine (∼5mg·kg body weight) or placebo were administered prior to a moderate pain trial. Nine caffeine “responders” were re-tested and ask to regulate their exercise intensity at a “strong” pain level (a “5” on a 0-10 pain scale). A caffeine (∼5mg·kg body weight) or placebo was again ingested prior to exercise.

RESULTS: Participants performed more work (p=0.008) and covered more distance (p=0.008) at a higher average power output (p=0.009) and V˙O2 (p=0.019), for an identical amount of “moderate” muscle pain in the caffeine condition. When exercising at a rating of a “5” caffeine did not increase total work, distance covered or V˙O2 for an identical amount of “strong” pain in the 9 caffeine “responders”.

CONCLUSION: Our findings indicate caffeine increases work performed during exercise eliciting a moderate amount of a pain. However, a threshold level of muscle pain may exist above which antagonism of adenosine receptors alone does not induce a hypoalgesic effect.