Caffeine and sports activity: a review

Area of Science:

• Exercise Physiology
• Biochemistry
• Sports Science

Background:

• Caffeine is a widely consumed methylxanthine with potential ergogenic effects.
• Its mechanisms of action involve calcium mobilization, phosphodiesterase inhibition, and adenosine receptor antagonism.
• Adenosine receptor antagonism is considered the primary in vivo mechanism at typical consumption levels.

Purpose of the Study:

• To elucidate the cellular mechanisms underlying caffeine's ergogenic effects.
• To examine caffeine's impact on muscle contractility, exercise performance, and endurance.
• To highlight factors influencing caffeine's efficacy, such as tolerance.

Main Methods:

• Review of cellular and physiological mechanisms of caffeine.
• Analysis of caffeine's effects on calcium handling, cyclic AMP levels, and adenosine receptors.
• Evaluation of caffeine's impact on muscle contractility and endurance during various exercise intensities.

Main Results:

• Caffeine enhances muscle contractility and endurance during prolonged submaximal exercise.
• Its ergogenic effects are linked to adenosine receptor antagonism, increased catecholamine production, and enhanced lipolysis, leading to glycogen sparing.
• Caffeine shows no ergogenic effect on intense, short-duration exercise.

Conclusions:

• Caffeine's primary ergogenic benefit stems from adenosine receptor antagonism, improving endurance and time to exhaustion.
• Increased lipolysis and glycogen sparing contribute to enhanced performance during prolonged activity.
• Athletes must consider developing tolerance to methylxanthines to maximize caffeine's ergogenic potential.