MONITORING CHANGES IN
CORE TEMPERATURE AND HEAT LOAD
IN WHEELCHAIR BASKETBALL ATHLETES DURING MAJOR COMPETITIONS Heather Logan-Sprenger, PhD, Lead of Physiology, Research & Innovation, Canadian Sport Institute Ontario
heelchair basketball (WCB) is one of the most popular and acclaimed sports within the Paralympic Games and is played by athletes who have a physical disability such as an amputation, spinal cord injury (SCI), cerebral palsy, and/or others (multiple sclerosis, muscular dystrophy, polio, and spinal bifida) which prevents them from playing able-bodied (AB) basketball1. WCB is an intermittent, high-intensity and physically demanding sport, with 28% of the active game being high intensity and anaerobic, 24% aerobic, and 48% recovery2.
Temperature regulation during exercise appears to be a challenge among athletes, even during moderate ambient temperatures (~21°C)3-5. During exercise, the subsequent elevation in metabolic rate results in increased muscular power (~20%) and heat production (~80%)6,7. Thus, temperature regulation processes must act to dissipate the heat produced to maintain core body temperature (Tc) over a narrow range8. A rise in Tc occurs when the increased heat production exceeds the maximal capacity of heat dissipation9. If Tc increases to ≥40°C, hyperthermia develops9 and results in a reduction in exercise performance and/or the development of heat related illnesses (heat exhaustion, heat cramps, and heat stroke)10,11. In comparison to AB athletes, many para-athletes exhibit a reduced or impaired ability to regulate Tc, often due to a reduced afferent input to the thermoregulatory centre12,13. Athletes with an amputation or SCI
HP SIRCuit Summer 2016
experience an impaired sweating capacity and vasomotor control below the level of injury14. Heat stress may also lead to adverse outcomes, such as exacerbating side effects associated with the disability, as in athletes with multiple sclerosis, cerebral palsy, muscular dystrophy, and polio12,15,16. Indoor WCB has been categorized as possessing an intermediate risk for heat-related illness12. Thus, any attempt to delay the rise in Tc during exercise may support both optimal performance and the health and well-being of the para-athlete. Moreover, much of what we know regarding thermoregulation has been studied using AB athletes, while some may argue the need for research is greater for para-athletes. Therefore, in preparation for future competitions held in hot climates, in particular the upcoming 2016 Olympic and Paralympic Games in Rio de Janeiro, the objectives of this study were as follows:
1) To identify players on the women’s National WCB team who may be at a greater risk of heat-related illness and fatigue in the later quarters of a game due to high heat accumulation. 2) To implement appropriate cooling strategies to mitigate the effects of a high sustained core temperature on performance. 3) To assess the effectiveness of the cooling intervention on Tc responses during a follow-up game.