In some cycling events, cyclists take acetaminophen, an approved pain reliever to increase pain tolerance and presumably increase cycling performance. Several cycling organizations have deemed this as acceptable practice since this has been done even before during the days when aspirin was made available and the drug did not have chemical effects which would give the athlete an unfair advantage.
In January 2010, a study was published in the Journal of Applied Physiology which aimed to establish whether acetaminophen improves performance of self-paced exercise through the reduction of perceived pain, 13 trained male cyclists performed a self-paced 10-mile (16.1 km) cycle time trial (TT) following the ingestion of either acetaminophen (ACT) or a placebo (PLA), administered in randomized double-blind design.
TT were completed in a significantly faster time (t(12) = 2.55, P < 0.05) under the ACT condition (26 min 15 s +/- 1 min 36 s vs. 26 min 45 s +/- 2 min 2 s). Power output (PO) was higher during the middle section of the TT in the ACT condition, resulting in a higher mean PO (P < 0.05) (265 +/- 12 vs. 255 +/- 15 W). Blood lactate concentration (B[La]) and heart rate (HR) were higher in the ACT condition (B[La] = 6.1 +/- 2.9 mmol/l; HR = 87 +/- 7%max) than in the PLA condition (B[La] = 5.1 +/- 2.6 mmol/l; HR = 84 +/- 9%max) (P < 0.05).
No significant difference in rating of perceived exertion (ACT = 15.5 +/- 0.2; PLA = 15.7 +/- 0.2) or perceived pain (ACT = 5.6 +/- 0.2; PLA = 5.5 +/- 0.2) (P > 0.05) was observed. Using acetaminophen, participants cycled at a higher mean PO, with an increased HR and B[La], but without changes in perceived pain or exertion. Consequently, completion time was significantly faster.
These findings support the notion that exercise is regulated by pain perception, and increased pain tolerance can improve exercise capacity. In our experience, before an event, athletes usually take acetaminophen and other approved pain relievers. This is not only seen in the sport of cycling but in other sports as well.