Using the Placebo Effect to Isolate Control Mechanisms of Athletic Performance: A Research Protocol

Abstract

Placebo effects are common in all areas of medicine and beyond and thus, are also present when ergogenic aids are used to enhance performance in athletes. While they usually are regarded as secondary and a nuisance in relation to performance-improving nutritional supplements, we here propose to utilize them to investigate central control mechanisms of athletic performance. Following a brief review of the current literature on placebo effects in sports, we outline a research protocol designed to understand the neurobiological basis of endurance performance, limiting factors and the integration of central and peripheral fatigue mechanisms. A placebo response to ergogenic aids will be elicited to isolate and study both central and peripheral components of performance regulation. This protocol employs endurance performance measurements, electroencephalography, functional near-infrared spectroscopy and ratings of perceived exertion in order to quantify the performance altering placebo response elicited by a nutritional ergogenic aid. A model is proposed integrating the placebo response with current theories of performance determining and limiting factors such as the central governor model and the central fatigue hypothesis. The first experiment is concerned with the influence of the mode of administration of an ergogenic aid on endurance performance. In the second experiment, the cortical processes underlying increased motor performance will be investigated using electroencephalography. The third experiment will employ functional near-infrared spectroscopy to look at the integration of cortico-muscular feed forward and feedback signaling pathways mediating fatigue. This protocol provides an integrative approach for neuroscience and sports science research, investigating cortical processes involved in the placebo induced exploitation of residual central and peripheral resources causing better athletic performance. It also will affect prevention and treatment of diseases which may be caused by a lack of physical activity or which may cause a decrease in the ability to be physically active.