losing 1.94% BM in skaters. 9 The high sweat rates and apparent physiological demands of ice hockey goaltenders suggest that mild DEH may impair performance, but this has not been examined. This study examined the effects of mild DEH (∼2% BM loss) on on-ice thermoregulation, HR, fatigue, and performance
Devin G. McCarthy, Kate A. Wickham, Tyler F. Vermeulen, Danielle L. Nyman, Shane Ferth, Jamie M. Pereira, Dennis J. Larson, Jamie F. Burr and Lawrence L. Spriet
Steve H. Faulkner and Philippa Jobling
thermoregulatory effects during simulated TT cycling. The primary aim of the present study was to investigate the relationship between hip angle, thermoregulation, economy, and performance. A secondary aim was to develop a unit of measurement that is sensitive to changes in rider position with respect to their
Martin J. Barwood, Joe Kupusarevic and Stuart Goodall
provide a greater benefit to thermal perception thereby driving behavioral thermoregulation. Our data suggest that only TS was significantly improved although TC did alter subjectively in the hypothesized direction. The performance change through perceptual mechanisms did not manifest itself through
Ben T. Stephenson, Sven P. Hoekstra, Keith Tolfrey and Victoria L. Goosey-Tolfrey
finite literature concerning thermoregulation in Paralympic sport has centered on athletes with a spinal cord injury (SCI) due to their high propensity for thermal strain caused by impaired autonomic function and therefore sudomotor and vasomotor control. 2 Research has characterized the
M.J. Anderson, J.D. Cotter, A.P. Garnham, D.J. Casley and M.A. Febbraio
This study examined the effect of glycerol ingestion on fluid homeostasis, thermoregulation, and metabolism during rest and exercise. Six endurance-trained men ingested either 1 g glycerol in 20 ml H2O · kg−1 body weight (bw) (GLY) or 20 ml H2O · kg−1 bw (CON) in a randomized double-blind fashion, 120 min prior to undertaking 90 min of steady state cycle exercise (SS) at 98% of lactate threshold in dry heat (35 °C, 30% RH), with ingestion of CHO-electrolyte beverage (6% CHO) at 15-min intervals. A 15-min cycle, where performance was quantified in kJ, followed (PC). Pre-exercise urine volume was lower in GLY than CON (1119 ± 97 vs. 1503 ± 146 ml · 120 min−1; p < .05). Heart rate was lower (p < .05) throughout SS in GLY, while forearm blood flow was higher (17.1 ± 1.5 vs. 13.7 ± 3.0 ml · 100 g tissue · min−1; < .05) and rectal temperature lower (38.7 ± 0.1 vs. 39.1 ± 0.1 °C; p < .05) in GLY late in SS. Despite these changes, skin and muscle temperatures and circulating catecholamines were not different between trials. Accordingly, no differences were observed in muscle glycogenolysis, lactate accumulation, adenine nucleotide, and phosphocreatine degradation or inosine 5′-monophosphate accumulation when comparing GLY with CON. Of note, the work performed during PC was 5% greater in GLY (252 ± 10 vs. 240 ± 9 kJ;p < .05). These results demonstrate that glycerol, when ingested with a bolus of water 2 hours prior to exercise, results in fluid retention, which is capable of reducing cardiovascular strain and enhancing thermoregulation. Furthermore, this practice increases exercise performance in the heat by mechanisms other than alterations in muscle metabolism.
Catriona A. Burdon, Helen T. O’Connor, Janelle A. Gifford and Susan M. Shirreffs
Increased core temperature (Tc), impaired cardiovascular function, and dehydration contribute to fatigue during prolonged exercise in the heat. Although many studies have examined mechanisms addressing these factors, few have investigated the effect of cold beverage temperature on thermoregulation and exercise performance in the heat.
Citations from MEDLINE (Ovid), Sport Discus (EBSCOhost), AUSPORT and AusportMed (Informit), Web of Science, and SCOPUS were identified from the earliest record until September 2008 using the search terms drink temperature, beverage temperature, fluid temperature, water temperature, and cold fluid combined with body temperature and thermoregulation. To be included, studies needed to assess core or rectal temperature during exercise in moderate or hot environmental conditions. After quality rating was completed by two reviewers, the difference in mean Tc and exercise performance was calculated.
Ten studies meeting search inclusion criteria were available for analysis. Three were excluded because sufficient detail or statistical data were not reported. A meta-analysis was not performed because the studies were deemed too different to group. Three of the remaining 7 studies found modulated Tc with cold beverage consumption, and from the 4 that conducted exercise performance tests, performance improved by 10% with cold fluids.
Cold fluid may attenuate Tc rise and improve exercise performance in the heat; however, study findings are mixed. Research using well-trained athletes and fluid-ingestion protocols replicating competition scenarios is required. Potential sensory effects of cold fluid in maintaining motivation also need to be assessed as a mechanism underpinning improved performance.
Fergus K. O’Connor, Steven E. Stern, Thomas M. Doering, Geoffrey M. Minett, Peter R. Reaburn, Jonathan D. Bartlett and Vernon G. Coffey
reduce physical performance in hot conditions. The vast majority of previous research on thermoregulation during exercise in hot environments has focused on the endurance athlete, and there is a paucity of available data examining the effect of exercise in the heat on the team-sport athlete. 6 Some
Coen C.W.G. Bongers, Dominique S.M. ten Haaf, Nicholas Ravanelli, Thijs M.H. Eijsvogels and Maria T.E. Hopman
regulation during exercise in water and air . Acta Physiol Scand . 1976 ; 98 ( 4 ): 500 – 508 . PubMed ID: 998300 doi:10.1111/j.1748-1716.1976.tb10342.x 10.1111/j.1748-1716.1976.tb10342.x 998300 18. Havenith G . Individualized model of human thermoregulation for the simulation of heat stress response
Michael J. Zurawlew, Jessica A. Mee and Neil P. Walsh
additional exercise. As sleeping patterns can influence thermoregulation, 1 participants were instructed to sleep between 2200 and 0700 hours to ensure a similar circadian pattern prior to each experimental trial. This was confirmed by monitoring sleep, using an ActiGraph worn on the nondominant arm with
Christopher J. Stevens, Megan L.R. Ross, Amelia J. Carr, Brent Vallance, Russ Best, Charles Urwin, Julien D. Périard and Louise Burke
in cardiovascular function and thermoregulation. 1 , 11 It should also be highlighted that the post 10,000-m performance test was conducted in cooler conditions (22.8°C [0.3°C]) than the pretest (28.7°C [1.2°C]), which likely contributed to the large performance improvements recorded for both groups