Quinine Ingestion During the Latter Stages of a 3,000-m Time Trial Fails to Improve Cycling Performance

Mouth Rinsing and Ingesting Unpleasant Salty or Bitter Solutions After Heavy-Intensity Cycling Does Not Influence Sprint Performance or Knee-Extensor Force in Trained Cyclists

PURPOSE

The present study investigated the effect of unpleasant salty or bitter tastes on cycling sprint performance and knee-extensor force characteristics in different fatigue states.

METHODS

Following a familiarization session, 11 trained male cyclists completed 3 experimental trials (salty, bitter, and water) in a randomized crossover order. In each trial, participants cycled at 85% of the respiratory compensation point for 45 minutes and then, after a 5-minute rest, completed a 1-minute sprint. Muscle-force characteristics were assessed using 2 knee-extensor maximal voluntary contractions immediately before, between, and after the cycling efforts. Participants mouth-rinsed and ingested 25 mL of test solution (salty, bitter, and water) immediately before each maximal voluntary contractions and the 1-minute sprint.

RESULTS

There were no significant differences in mean and peak power output during the 1-minute sprint between conditions (mean power: 528 [71] W, 524 [70] W, and 521 [80] W in the water, salt, and bitter conditions, respectively). Muscle-force production was impaired in all conditions after the heavy-intensity cycling, evidenced by a decline in maximum force production (P = .01, effect size = 0.32) and 100- to 200-millisecond impulse (P = .04, effect size = 0.27). However, there were no significant differences between conditions in maximal force or impulse measures at rest or after exercise.

CONCLUSION

These data question whether unpleasant tastes can influence muscle-force production and do not support that they may be used as an ergogenic aid for a cycling sprint performed under fatigued conditions.

Nutritional approaches to counter performance constraints in high-level sports competition

New Findings

What is the topic of this review?

The nutritional strategies that athletes use during competition events to optimize performance and the reasons they use them.

What advances does it highlight?

A range of nutritional strategies can be used by competitive athletes, alone or in combination, to address various event‐specific factors that constrain event performance. Evidence for such practices is constantly evolving but must be combined with understanding of the complexities of real‐life sport for optimal implementation.

Abstract

High‐performance athletes share a common goal despite the unique nature of their sport: to pace or manage their performance to achieve the highest sustainable outputs over the duration of the event. Periodic or sustained decline in the optimal performance of event tasks, involves an interplay between central and peripheral phenomena that can often be reduced or delayed in onset by nutritional strategies. Contemporary nutrition practices undertaken before, during or between events include strategies to ensure the availability of limited muscle fuel stores. This includes creatine supplementation to increase muscle phosphocreatine content and consideration of the type, amount and timing of dietary carbohydrate intake to optimize muscle and liver glycogen stores or to provide additional exogenous substrate. Although there is interest in ketogenic low‐carbohydrate high‐fat diets and exogenous ketone supplements to provide alternative fuels to spare muscle carbohydrate use, present evidence suggests a limited utility of these strategies. Mouth sensing of a range of food tastants (e.g., carbohydrate, quinine, menthol, caffeine, fluid, acetic acid) may provide a central nervous system derived boost to sports performance. Finally, despite decades of research on hypohydration and exercise capacity, there is still contention around their effect on sports performance and the best guidance around hydration for sporting events. A unifying model proposes that some scenarios require personalized fluid plans while others might be managed by an ad hoc approach (ad libitum or thirst‐driven drinking) to fluid intake.