Caffeine During Exercise Boosts Performance Even in the Heat

Caffeine is commonly known to enhance exercise performance, but its benefits may be reduced in hot environments. Previous findings revealed that consuming caffeine before exercising in the heat can increase physiological strain, including excessive breathing caused by a rise in core body temperature and reduced cerebral blood flow (1^✔ ✔Trusted Source
In-Exercise Caffeine Improves Exercise Performance in the Heat Without Exacerbating Hyperventilation and Brain Hypoperfusion

Go to source). These reactions stem from a rapid spike in blood caffeine levels prior to exercise, which appears to hinder its performance-boosting effects.

Caffeine Intake Timing and Performance

In this study, researchers investigated the effects of intake of moderate doses of caffeine during exercise on performance during prolonged exercise in the heat in healthy young men and women.

The results showed that blood caffeine levels gradually increased during exercise, and the duration of high-intensity exercise performed at the end of exercise was prolonged. In addition, the rating of perceived exertion was lower immediately before high-intensity exercise. By contrast, caffeine intake did not worsen hyperthermia-induced hyperventilation and cerebral hypoperfusion during exercise.

Performance Benefits Without Added Physiological Burden

These findings indicate that consuming caffeine during exercise may be an effective strategy for improving exercise performance during prolonged exercise in the heat. Moreover, this approach does not worsen physiological strain at corresponding time points compared with a no-caffeine condition.

However, caffeine intake resulted in greater cardiorespiratory and temperature strain at the end of exercise because of the improved exercise performance.

Reference:

1. In-Exercise Caffeine Improves Exercise Performance in the Heat Without Exacerbating Hyperventilation and Brain Hypoperfusion - (https://journals.lww.com/acsm-msse/abstract/9900/in_exercise_caffeine_improves_exercise_performance.847.aspx)

Source-Eurekalert