King Grub
2018-10-03, 08:56
PURPOSE:
Acute acetaminophen (ACT) ingestion has been shown to enhance cycling time-trial performance. The purpose of this study was to assess whether ACT ingestion enhances muscle activation and critical power (CP) during maximal cycling exercise.
METHODS:
Sixteen active male participants completed two 3-min all-out tests against a fixed resistance on an electronically-braked cycle ergometer 60 minutes following ingestion of 1 g ACT or placebo (maltodextrin, PL). CP was estimated as the mean power output over the final 30 s of the test and W' (the curvature constant of the power-duration relationship) was estimated as the work done above CP. The femoral nerve was stimulated every 30 s to measure membrane excitability (M-wave) and surface electromyography (EMGRMS) was recorded continuously to infer muscle activation.
RESULTS:
Compared to PL, ACT ingestion increased CP (ACT: 297 ± 32 vs PL: 288 ± 31 W, P<0.001) and total work done (ACT: 66.4 ± 6.5 vs PL: 65.4 ± 6.4 kJ, P=0.03) without impacting W' (ACT: 13.1 ± 2.9 vs PL: 13.6 ± 2.4 kJ, P=0.19) or the M-wave amplitude (P=0.66) during the 3-min all-out cycling test. Normalized EMG<sub>RMS</sub> amplitude declined throughout the 3-min protocol in both PL and ACT conditions; however, the decline in EMG<sub>RMS</sub> was attenuated in the ACT condition, with the EMG<sub>RMS</sub> amplitude being greater compared to PL over the last 60 s of the test (P=0.04).
CONCLUSION:
These findings indicate that acute ACT ingestion might increase performance and CP during maximal cycling exercise by enhancing muscle activation.
Appl Physiol Nutr Metab. 2018 Sep 29. Acetaminophen ingestion improves muscle activation and performance during a 3-min all-out cycling test.
Acute acetaminophen (ACT) ingestion has been shown to enhance cycling time-trial performance. The purpose of this study was to assess whether ACT ingestion enhances muscle activation and critical power (CP) during maximal cycling exercise.
METHODS:
Sixteen active male participants completed two 3-min all-out tests against a fixed resistance on an electronically-braked cycle ergometer 60 minutes following ingestion of 1 g ACT or placebo (maltodextrin, PL). CP was estimated as the mean power output over the final 30 s of the test and W' (the curvature constant of the power-duration relationship) was estimated as the work done above CP. The femoral nerve was stimulated every 30 s to measure membrane excitability (M-wave) and surface electromyography (EMGRMS) was recorded continuously to infer muscle activation.
RESULTS:
Compared to PL, ACT ingestion increased CP (ACT: 297 ± 32 vs PL: 288 ± 31 W, P<0.001) and total work done (ACT: 66.4 ± 6.5 vs PL: 65.4 ± 6.4 kJ, P=0.03) without impacting W' (ACT: 13.1 ± 2.9 vs PL: 13.6 ± 2.4 kJ, P=0.19) or the M-wave amplitude (P=0.66) during the 3-min all-out cycling test. Normalized EMG<sub>RMS</sub> amplitude declined throughout the 3-min protocol in both PL and ACT conditions; however, the decline in EMG<sub>RMS</sub> was attenuated in the ACT condition, with the EMG<sub>RMS</sub> amplitude being greater compared to PL over the last 60 s of the test (P=0.04).
CONCLUSION:
These findings indicate that acute ACT ingestion might increase performance and CP during maximal cycling exercise by enhancing muscle activation.
Appl Physiol Nutr Metab. 2018 Sep 29. Acetaminophen ingestion improves muscle activation and performance during a 3-min all-out cycling test.