The idea that some mild degree of pre-cooling (a slight reduction in body core temperature of 0.5-1.0 °C prior to exercise) might reduce thermal stress during exercise in the heat has been around for over 20 years. Many studies have demonstrated that pre-cooling results in less thermal strain during exercise, i.e. a lower body core temperature during exercise of similar intensity. While pre-cooling has been shown to modify (improve) the thermoregulatory responses to exercise not all studies have demonstrated a clear improvement in performance. Lately, using an ice vest has been shown to provide adequate pre-cooling to lower body core temperature prior to exercise and appears almost as effective as more sophisticated pre-cooling procedures (i.e. water immersion, whole body cooling garments) in lowering body temperature. Use of such ice-vests has allowed researchers to get out of the laboratory and evaluate pre-cooling in the field. Recent fieldwork has verified that pre-cooling with an ice-vest can reduce body temperature and reduce thermoregulatory strain during most, but not all real or simulated athletic competitions. Overall, endurance athletic events seem to respond best to ice-vest pre-cooling. Fieldwork has verified the ability to reduce the rise in core temperature under actual 4-5 km race conditions. In addition, pre-cooling with an ice vest prior to an interval workout (8 x 1000 m) is able to keep body core temperature lower during the first 5-6 repeats. In addition, peak power output during a high intensity cycling exercise (Wingate test) is higher in athletes who undergo ice vest pre-cooling. In contrast, no real advantage has been ascribed to pre-cooling individuals performing high intensity-intermittent exercise (simulated soccer match). Laboratory tests have provided good evidence that pre-cooling with an ice vest can reduce thermal strain and improved performance. However, improved athletic performance from ice vest pre-cooling in competitive events has not been verified. Overall, ice vest pre-cooling does not impair performance but does reduce thermal strain in competitive athletes. Regardless of its impact on performance ice-vest pre-cooling should be beneficial to the health and safety of endurance athletes.
Gary W. Mack, PhD, FACSM
Department of Exercise Sciences, Brigham Young University
Hello Gary, With regard to your comment "In contrast, no real advantage has been ascribed to pre-cooling individuals performing high intensity-intermittent exercise (simulated soccer match)" can I just alert you to our work that specifically looked at intermittent sprint exercise in the heat which showed a definite benefit in improving performance and delaying the rise in core temp? 32. Webborn, N., et al., The effect of two cooling strategies on thermoregulatory responses of tetraplegic athletes during repeated intermittent exercise in the heat. J Appl Physiol, 2005: p. 00784.2004.41. Castle, P, MacDonald, A, Philp, A, Webborn, A, Watt, P and Maxwell, N (2006) Precooling leg muscle improves intermittent sprint exercise performance in hot, humid conditions. Journal of Applied Physiology, 100 (4). pp. 1377-1384. ISSN 1522-1601 43. Nick Webborn, Michael J Price, Paul Castle, and Victoria Goosey-Tolfrey Cooling strategies improve intermittent sprint performance in the heat of athletes with tetraplegia British Journal of Sports Medicine, Jun 2008
Hope this is of interest.
Posted by: Nick Webborn | August 28, 2008 at 08:56 AM
Hello Gary, With regard to your comment "In contrast, no real advantage has been ascribed to pre-cooling individuals performing high intensity-intermittent exercise (simulated soccer match)" can I just alert you to our work that specifically looked at intermittent sprint exercise in the heat which showed a definite benefit in improving performance and delaying the rise in core temp? 32. Webborn, N., et al., The effect of two cooling strategies on thermoregulatory responses of tetraplegic athletes during repeated intermittent exercise in the heat. J Appl Physiol, 2005: p. 00784.2004.41. Castle, P, MacDonald, A, Philp, A, Webborn, A, Watt, P and Maxwell, N (2006) Precooling leg muscle improves intermittent sprint exercise performance in hot, humid conditions. Journal of Applied Physiology, 100 (4). pp. 1377-1384. ISSN 1522-1601 43. Nick Webborn, Michael J Price, Paul Castle, and Victoria Goosey-Tolfrey Cooling strategies improve intermittent sprint performance in the heat of athletes with tetraplegia British Journal of Sports Medicine, Jun 2008
Hope this is of interest.
Posted by: Nick Webborn | August 28, 2008 at 08:57 AM