Background
Exercise tolerance is a pivotal factor in determining athletic competitive success, as well as mobility and quality of life in elderly individuals and those afflicted by chronic ailments. Since tolerance to endurance exercise is closely related to the perception of effort, any measure that influences this perception may also impact endurance performance.
Methods
The aim of this brief review was to evaluate how dietary interventions can improve endurance performance by reducing perceived effort. We contextualize our review within theoretical frameworks that consider effort perception to be a key regulator of endurance performance. Next, we integrate evidence on the ergogenic effects of various dietary interventions with existing knowledge on the perception of effort.
Results
Dietary interventions may enhance endurance performance by improving motor command transmission, slowing fatigue development and related compensatory increase in motor command, and/or modifying the activity of brain networks involved in effort perception and fatigue. Beta-alanine, caffeine or carbohydrate mouth rinsing are examples of evidence-based ergogenic aids. The impact on endurance performance is achieved through their potential to overcome cardiorespiratory and metabolic limitations or through modulation of the central nervous system. Other dietary supplements, such as branched-chain amino acids, citrulline, taurine, and probiotics, may indirectly impact performance by influencing tolerance to physical exertion.
Conclusion
While current evidence supports a key role for dietary interventions on endurance performance by influencing individuals' perceived effort, more research is needed to determine the optimal doses and precise formulations for different sports, in order to employ a personalized strategy.