Grant: Discovery Grants Program - Individual

Over the past decade, in addition to high ambient temperatures, a high body temperature has become recognized as a major direct cause of decreased voluntary exercise capacity and tolerance. However, the mechanism by which body temperature influences exercise capacity remains a major source of debate. A number of studies have suggested that the achievement of a critically high body temperature directly causes fatigue during voluntary, whole-body exercise. Alternately, other studies have proposed that, in advance of the point of catastrophic collapse, the human organism alters its workload on an anticipatory basis by integrating temperature and other inputs, such that the exercise can be completed as efficiently as possible while minimizing the risk of heat exhaustion and collapse. These two models have often been pitted against each other as contradictory. However, another perspective may be that the two models are actually complementary and not necessary exclusive of each other, but arose as a by-product of different research approaches. Therefore, the objectives of this research program are to determine whether the two models can indeed co-exist and the relative contribution of central and regional peripheral thermal afferents to neuromuscular function. The themes and primary objectives of the proposed research program include:1. understanding how peripheral and regional temperature interact with central core temperature to influence muscle activation and force production and control, and determining the relative influence of core and skin temperature on neuromuscular function and exercise capacity.2. understanding the mechanisms underlying the apparently differing effects of core and peripheral temperature across different types of maximal exercise, ranging from brief, all-out contractions of a single muscle through to voluntary, whole-body exercise.