Ingestion of Caffeine and Carbohydrate Increases Average Power Output during a 10 mile Time Trial in Both Male and Female Cyclists

Ryan D Mitchell,Amada Podczerwinski

doi:10.12691/ajssm-5-3-3

Abstract

Previous researchers observed that elite male cyclists’ performance improves with combined ingestion of caffeine and carbohydrate. We carried out this study to determine if similar outcomes would be observed in a group of cyclists varying widely in age and racing experience as well as gender. We administered carbohydrate with or without the addition of 6 mg/kg body weight caffeine in a counterbalanced blind manner to ten trained male and female cyclists in the fed state one hour prior to 20 minutes of steady-state (SS) cycling at 60% VO2max power followed by a simulated 10-mile time trial (TT). Ventilation (VE), rate of oxygen consumption (VO2), respiratory exchange ratio (RER), and rate of perceived exertion (RPE) were measured during the SS, whereas completion time, average power output, heart rate (HR) and RPE were measured during the TT. The addition of caffeine resulted in a significant reduction in completion time (1.9%) and increased the average power output (5.0%), as well as significantly higher heart rates during the TT (2.9%). We observed no significant differences in VE, VO2, RER, RPE, and HR during the SS between treatments. Our data shows that the ingestion of 6 mg/kg of caffeine in combination with a 7.5% carbohydrate solution in male and female cyclists in the fed state improves short duration time trial performance as measured by completion time and average power output. These findings can be of great value to cyclists across a wide range of age and experience.

Highlights

IntroductionMultiple researchers have examined the effects of carbohydrate and caffeine on long-duration (greater than one hour) cycling, with time to exhaustion as the primary measure
Multiple researchers have examined the effects of carbohydrate and caffeine on long-duration cycling, with time to exhaustion as the primary measure
Researchers of only two studies, focused on the effects of carbohydrate and caffeine on short-duration, high intensity cycling and measured performance. [1,2] Kovacs et al examined the effects of the addition of caffeine to a carbohydrate solution on one hour time trial performance of male cyclists in the fed state

Summary

Introduction

Multiple researchers have examined the effects of carbohydrate and caffeine on long-duration (greater than one hour) cycling, with time to exhaustion as the primary measure. Researchers of only two studies, focused on the effects of carbohydrate and caffeine on short-duration (one hour or less), high intensity cycling and measured performance. [1,2] Kovacs et al examined the effects of the addition of caffeine to a carbohydrate solution on one hour time trial performance of male cyclists in the fed state. The most important role of carbohydrate ingestion during exercise (especially in short duration, high intensity exercise) may be to maintain blood glucose in support of the central nervous system (CNS). To determine a potential mechanism, Carter et al studied the effects of a carbohydrate mouth rinse compared to a water rinse on one hour time trial performance of cyclists in the fasting state. To determine a potential mechanism, Carter et al studied the effects of a carbohydrate mouth rinse compared to a water rinse on one hour time trial performance of cyclists in the fasting state. [8] The researchers found that cyclists power output increased with the carbohydrate mouth rinse, suggesting that carbohydrates increase the central drive or motivation via carbohydrate receptors in the mouth

Results

Discussion

Conclusion