title: Influence of acetaminophen on performance during time trial cycling.
abstract: 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.
authors.affiliation: Dept. of Sport and Exercise Sciences, Univ. of Bedfordshire, Polhill Campus, Polhill Ave., Bedford MK419EA, United Kingdom. Lex.Mauger@beds.ac.uk
authors.forename: Alexis R
authors.initials: AR
authors.lastname: Mauger
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Jones
authors.forename: Craig A
authors.initials: CA
authors.lastname: Williams
mesh_terms: D000082:Acetaminophen / Q000008:administration & dosage*; D000328:Adult; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage; D001642:Bicycling; D004311:Double-Blind Method; D005080:Exercise Test / Q000009:adverse effects*; D006801:Humans; D008297:Male; D010146:Pain / Q000209:etiology* / Q000517:prevention & control*; D010147:Pain Measurement / Q000187:drug effects; D005082:Physical Exertion / Q000187:drug effects*; D015990:Placebo Effect; D011597:Psychomotor Performance / Q000187:drug effects*
chemical_list: D018712:Analgesics, Non-Narcotic; D000082:Acetaminophen