TY - JOUR

T1 - Acute acetaminophen ingestion does not alter core temperature or sweating during exercise in hot-humid conditions

AU - Coombs, G B

AU - Cramer, M N

AU - Ravanelli, N M

AU - Morris, N B

AU - Jay, O

N1 - © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

PY - 2015/6

Y1 - 2015/6

N2 - Acute acetaminophen (ACT) ingestion has been reported to reduce thermal strain during cycling in the heat. In this study, nine active participants ingested 20 mg of ACT per kg of total body mass (ACT) or a placebo (PLA), 60 min prior to cycling at a fixed rate of metabolic heat production (ACT: 8.3 ± 0.3 W/kg; PLA: 8.5 ± 0.5 W/kg), which was equivalent to 55 ± 6% VO2max , for 60 min at 34.5 ± 0.1 °C, 52 ± 1% relative humidity. Resting rectal temperature (Tre ; ACT: 36.70 ± 0.17 °C; PLA: 36.80 ± 0.16 °C, P = 0.24), esophageal temperature (Tes ; ACT: 36.54 ± 0.22 °C; PLA: 36.61 ± 0.17 °C, P = 0.50) and mean skin temperature (Tsk ; ACT: 34.00 ± 0.14 °C; PLA: 33.96 ± 0.20 °C, P = 0.70) were all similar among conditions. At end-exercise, no differences in ΔTre (ACT: 1.12 ± 0.15 °C; PLA: 1.11 ± 0.21 °C, P = 0.92), ΔTes (ACT: 0.90 ± 0.28 °C; PLA: 0.88 ± 0.23 °C, P = 0.84), ΔTsk (ACT: 0.80 ± 0.39 °C; PLA: 0.70 ± 0.46 °C, P = 0.63), mean local sweat rate (ACT: 1.02 ± 0.15 mg/cm(2) /min; PLA: 1.02 ± 0.13 mg/cm(2) /min, P = 0.98) and whole-body sweat loss (ACT: 663 ± 83 g; PLA: 663 ± 77 g, P = 0.995) were evident. Furthermore, ratings of perceived exertion and thermal sensation and thermal comfort were not different between ACT and PLA conditions. In conclusion, ACT ingested 60 min prior to moderate intensity exercise in hot-humid conditions does not alter physiologic thermoregulatory control nor perceived strain.

AB - Acute acetaminophen (ACT) ingestion has been reported to reduce thermal strain during cycling in the heat. In this study, nine active participants ingested 20 mg of ACT per kg of total body mass (ACT) or a placebo (PLA), 60 min prior to cycling at a fixed rate of metabolic heat production (ACT: 8.3 ± 0.3 W/kg; PLA: 8.5 ± 0.5 W/kg), which was equivalent to 55 ± 6% VO2max , for 60 min at 34.5 ± 0.1 °C, 52 ± 1% relative humidity. Resting rectal temperature (Tre ; ACT: 36.70 ± 0.17 °C; PLA: 36.80 ± 0.16 °C, P = 0.24), esophageal temperature (Tes ; ACT: 36.54 ± 0.22 °C; PLA: 36.61 ± 0.17 °C, P = 0.50) and mean skin temperature (Tsk ; ACT: 34.00 ± 0.14 °C; PLA: 33.96 ± 0.20 °C, P = 0.70) were all similar among conditions. At end-exercise, no differences in ΔTre (ACT: 1.12 ± 0.15 °C; PLA: 1.11 ± 0.21 °C, P = 0.92), ΔTes (ACT: 0.90 ± 0.28 °C; PLA: 0.88 ± 0.23 °C, P = 0.84), ΔTsk (ACT: 0.80 ± 0.39 °C; PLA: 0.70 ± 0.46 °C, P = 0.63), mean local sweat rate (ACT: 1.02 ± 0.15 mg/cm(2) /min; PLA: 1.02 ± 0.13 mg/cm(2) /min, P = 0.98) and whole-body sweat loss (ACT: 663 ± 83 g; PLA: 663 ± 77 g, P = 0.995) were evident. Furthermore, ratings of perceived exertion and thermal sensation and thermal comfort were not different between ACT and PLA conditions. In conclusion, ACT ingested 60 min prior to moderate intensity exercise in hot-humid conditions does not alter physiologic thermoregulatory control nor perceived strain.

KW - Acetaminophen/pharmacology

KW - Adult

KW - Antipyretics/pharmacology

KW - Bicycling/physiology

KW - Body Temperature/drug effects

KW - Body Temperature Regulation/drug effects

KW - Double-Blind Method

KW - Drug Administration Schedule

KW - Exercise/physiology

KW - Female

KW - Heat Stress Disorders/etiology

KW - Hot Temperature/adverse effects

KW - Humans

KW - Humidity/adverse effects

KW - Male

KW - Physical Exertion/drug effects

KW - Sweating/drug effects

KW - Treatment Outcome

U2 - 10.1111/sms.12336

DO - 10.1111/sms.12336

M3 - Article

C2 - 25943660

VL - 25 Suppl 1

SP - 96

EP - 103

JO - Scandinavian Journal of Medicine and Science in Sports

JF - Scandinavian Journal of Medicine and Science in Sports

SN - 0905-7188

ER -