Contribution of american football uniforms to the development of exercise-induced hyperthermia: A critically appraised topic

Clinical Scenario: Many American football players have died from exertional heatstroke, one of the leading causes of sudden death in athletes. These athletes are predisposed to exertional heatstroke, in part, because of their protective equipment. Few authors have systematically appraised the research to determine how much faster rectal temperature (Trec) increases when full American football uniforms generally consisting of a helmet, shoulder pads, jersey, pants with padding, socks, shoes, and underwear/compressions (PADS) are worn compared with no uniform so that clinicians can better plan and modify exercise sessions to prevent dangerous Trec (i.e., ≥40.5 °C). Clinical Question: How much faster does Trec increase when men wear a full American football uniform compared with workout clothing during exercise in the heat? Summary of Key Findings: The authors searched the literature for randomized controlled studies with PEDro scores >6 that compared Trec of males wearing PADS to a control uniform during exercise under controlled laboratory conditions. In all four studies, Trec increased faster when PADS were worn during exercise (PADS = 0.052 ± 0.007 °C/min and control = 0.039 ± 0.009 °C/min). The average effect size across studies was 1.4 ± 0.5. Clinical Bottom Line: PADS increase Trec significantly faster than lesser uniform ensembles. Clinicians should factor in equipment and alterations in exercise duration and rest break frequency to help prevent dangerous Trec in American football players. Strength of Recommendation: Given the large effect size and controlled experimental study designs, there is strong evidence that wearing PADS during exercise results in faster increases in body core temperature.