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Adaptation to Hot Environmental Conditions: An Exploration of the Performance Basis, Procedures and Future Directions to Optimise Opportunities for Elite Athletes

Abstract

Extreme environmental conditions present athletes with diverse challenges; however, not all sporting events are limited by thermoregulatory parameters. The purpose of this leading article is to identify specific instances where hot environmental conditions either compromise or augment performance and, where heat acclimation appears justified, evaluate the effectiveness of pre-event acclimation processes. To identify events likely to be receptive to pre-competition heat adaptation protocols, we clustered and quantified the magnitude of difference in performance of elite athletes competing in International Association of Athletics Federations (IAAF) World Championships (1999–2011) in hot environments (>25 °C) with those in cooler temperate conditions (<25 °C). Athletes in endurance events performed worse in hot conditions (~3 % reduction in performance, Cohen’s d > 0.8; large impairment), while in contrast, performance in short-duration sprint events was augmented in the heat compared with temperate conditions (~1 % improvement, Cohen’s d > 0.8; large performance gain). As endurance events were identified as compromised by the heat, we evaluated common short-term heat acclimation (≤7 days, STHA) and medium-term heat acclimation (8–14 days, MTHA) protocols. This process identified beneficial effects of heat acclimation on performance using both STHA (2.4 ± 3.5 %) and MTHA protocols (10.2 ± 14.0 %). These effects were differentially greater for MTHA, which also demonstrated larger reductions in both endpoint exercise heart rate (STHA: −3.5 ± 1.8 % vs MTHA: −7.0 ± 1.9 %) and endpoint core temperature (STHA: −0.7 ± 0.7 % vs −0.8 ± 0.3 %). It appears that worthwhile acclimation is achievable for endurance athletes via both short-and medium-length protocols but more is gained using MTHA. Conversely, it is also conceivable that heat acclimation may be counterproductive for sprinters. As high-performance athletes are often time-poor, shorter duration protocols may be of practical preference for endurance athletes where satisfactory outcomes can be achieved.

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References

  1. Ely MR, Cheuvront SN, Roberts WO, et al. Impact of weather on marathon-running performance. Med Sci Sports Exerc. 2007;39(3):487–93.

    Article  PubMed  Google Scholar 

  2. Racinais S, Mohr M, Buchheit M, et al. Individual responses to short-term heat acclimatisation as predictors of football performance in a hot, dry environment. Br J Sports Med. 2012;46(11):810–5.

    Article  PubMed  Google Scholar 

  3. Sawka MN, Wenger CB, Pandolf KB. Thermoregulatory responses to acute exercise-heat stress and heat acclimation. Compr Physiol 2011;Suppl. 14: Handbook of physiology, environmental physiology 157–85.

  4. Garrett AT, Rehrer NJ, Patterson MJ. Induction and decay of short-term heat acclimation in moderately and highly trained athletes. Sports Med. 2011;41(9):757–71.

    Article  PubMed  Google Scholar 

  5. Chalmers S, Esterman A, Eston R, et al. Short-term heat acclimation training improves physical performance: a systematic review, and exploration of physiological adaptations and application for team sports. Sports Med. 2014;44(7):971–88.

    Article  PubMed  Google Scholar 

  6. Taylor NA. Principles and practices of heat adaptation. J Hum Environ Syst. 2000;4(1):10.

    Google Scholar 

  7. Gonzalez-Alonso J, Calbet JA, Nielsen B. Metabolic and thermodynamic responses to dehydration-induced reductions in muscle blood flow in exercising humans. J Physiol. 1999;520(Pt 2):577–89.

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  8. Harding S. The tropical agenda. J Tropical Psychol. 2011;1(01):2–5.

    Article  Google Scholar 

  9. Sawka MN, Leon LR, Montain SJ, et al. Integrated physiological mechanisms of exercise performance, adaptation, and maladaptation to heat stress. Compr Physiol. 2011;1:46.

    Google Scholar 

  10. Corbett J, Neal RA, Lunt HC, et al. Adaptation to heat and exercise performance under cooler conditions: a new hot topic. Sports Med. 2014 (In press).

  11. Harrison MH. Effects on thermal stress and exercise on blood volume in humans. Physiol Rev. 1985;65(1):149–209.

    CAS  PubMed  Google Scholar 

  12. Senay LC. Changes in plasma volume and protein content during exposures of working men to various temperatures before and after acclimatization to heat: separation of the roles of cutaneous and skeletal muscle circulation. J Physiol. 1972;224(1):61–81.

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  13. O’Sullivan SE. The effects of exercise training on markers of endothelial function in young healthy men. Int J Sports Med. 2003;24(6):404–9.

    Article  PubMed  Google Scholar 

  14. Sawka MN, Hubbard RW, Francesconi RP, et al. Effects of acute plasma volume expansion on altering exercise-heat performance. Eur J Appl Physiol Occup Physiol. 1983;51(3):303–12.

    Article  CAS  PubMed  Google Scholar 

  15. Cadarette BS, Sawka MN, Toner MM, et al. Aerobic fitness and the hypohydration response to exercise-heat stress. Aviat Space Environ Med. 1984;55(6):507–12.

    CAS  PubMed  Google Scholar 

  16. Shapiro Y, Hubbard RW, Kimbrough CM, et al. Physiological and hematologic responses to summer and winter dry-heat acclimation. J Appl Physiol Respir Environ Exerc Physiol. 1981;50(4):792–8.

    CAS  PubMed  Google Scholar 

  17. Taylor NA, Cotter JD. Heat adaptation: guidelines for the optimisation of human performance. Int SportMed J. 2006;7(1).

  18. Cândido C, de Dear R, Ohba M. Effects of artificially induced heat acclimatization on subjects’ thermal and air movement preferences. Build Environ. 2012;49:251–8.

    Article  Google Scholar 

  19. Saunders AG, Dugas R, Tucker M, et al. The effects of different air velocities on heat storage and body temperature in humans cycling in a hot, humid environment. Acta Physiol Scand. 2005;183:241–55.

    Article  CAS  PubMed  Google Scholar 

  20. Galloway SD, Maughan RJ. Effects of ambient temperature on the capacity to perform prolonged cycle exercise in man. Med Sci Sports Exerc. 1997;29(9):1240–9.

    Article  CAS  PubMed  Google Scholar 

  21. Garrett AT, Creasy R, Rehrer NJ, et al. Effectiveness of short-term heat acclimation for highly trained athletes. Eur J Appl Physiol. 2011;112(5):1827–37.

    Article  PubMed  Google Scholar 

  22. Armstrong LE, Hubbard RW, DeLuca JP, et al. Heat acclimatization during summer running in the northeastern United States. Med Sci Sports Exerc. 1987;19(2):131–6.

    Article  CAS  PubMed  Google Scholar 

  23. Magalhaes FC, Amorin FT, Passos RL, et al. Heat and exercise acclimation increases intracellular levels of Hsp72 and inhibits exercise-induced increase in intracellular and plasma Hsp72 in Humans. Cell Stress Chaperon. 2010;15:10.

    Article  Google Scholar 

  24. Weller AS, Linnane AG, Jonkman AG, et al. Quantification of the decay and re-induction of heat acclimation in dry heat following 12 and 26 days without exposure to heat stress. Eur J Appl Physiol. 2007;102:57–66.

    Article  PubMed  Google Scholar 

  25. Edwards AM, Polman RCJ. Pacing in sport and exercise: a psychophysiological perspective. New York: Nova Science Publishers; 2012.

    Google Scholar 

  26. Montain SJ, Maughan RJ, Sawka MN. Heat acclimatization strategies for the 1996 Summer Olympics. Int J Athl Train Ther. 1996;1(3):5.

    Google Scholar 

  27. Mohr M, Krustrup P, Nybo L, et al. Muscle temperature and sprint performance during soccer matches-beneficial effect of re-warm-up at half-time. Scand J Med Sci Sports. 2004;14(3):156–62.

    Article  CAS  PubMed  Google Scholar 

  28. Iwase S, Cui J, Wallin BG, et al. Effects of increased ambient temperature on skin sympathetic nerve activity and core temperature in humans. Neurosci Lett. 2002;327(1):37–40.

    Article  CAS  PubMed  Google Scholar 

  29. Aoyagi Y, McLellan T, Shephard R. Effects of training and acclimation on heat tolerance in exercising men wearing protective clothing. Eur J Appl Physiol. 1994;68(3):234–45.

    Article  CAS  Google Scholar 

  30. Aoyagi Y, McLellan TM, Shephard R. Effects of 6 versus 12 days of heat acclimation on heat tolerance in lightly exercising men wearing protective clothing. Eur J Appl Physiol. 1995;71(2–3):187–96.

    Article  CAS  Google Scholar 

  31. Brade C, Dawson B, Wallman K. Effect of precooling on repeat sprint performance in the heat. J Sports Sci. 2013;31(7):779–86.

    Article  PubMed  Google Scholar 

  32. Buchheit M, Voss SC, Nybo L, et al. Phsyiological and performance adaptations to an in-season soccer camp in the heat: Associations with heart rate and heart rate variability. Scand J Med Sci Sports. 2011;21:477–85.

    Article  Google Scholar 

  33. Buono MJ, Heaney JH, Canine KM. Acclimation to humid heat lowers resting core temperature. Am J Physiol Reg I. 1998;274(43):R1295–9.

    CAS  Google Scholar 

  34. Chen T, Tsai P, Lin J, et al. Effect of short term heat acclimation on endurance time and skin blood flow in trained athletes. Open Access J Sports Med. 2012;4:161–70.

    Google Scholar 

  35. Cotter JD, Patterson MJ, Taylor NA. Sweat distribution before and after repeated heat exposure. Eur J Appl Physiol Occup Physiol. 1997;76(2):181–6.

    Article  CAS  PubMed  Google Scholar 

  36. Garrett AT, Goosens NG, Rehrer NJ, et al. Induction and decay of short-term heat acclimation. Eur J Appl Physiol. 2009;107(6):659–70.

    Article  PubMed  Google Scholar 

  37. Marshall HC, Campbell SA, Roberts CW, et al. Human physiological and heat shock protein 72 adaptations during the initial phase of humid-heat acclimation. J Therm Biol. 2007;32:8.

    Article  Google Scholar 

  38. Petersen CJ, Portus MR, Pyne DB, et al. Partial heat acclimation in cricketers using a 4-day high intensity cycling protocol. Int J Sports Physiol Perform. 2010;5:535–45.

    PubMed  Google Scholar 

  39. Sunderland C, Morris JG, Nevill ME. A heat acclimation protocol for team sports. Br J Sports Med. 2008;42(5):327–33.

    Article  CAS  PubMed  Google Scholar 

  40. Burk A, Timpmann S, Kreegipuu K, et al. Effects of heat acclimation on endurance capacity and prolactin response to exercise in the heat. Eur J Appl Physiol. 2012;112(12):4091–101.

    Article  CAS  PubMed  Google Scholar 

  41. Castle P, Mackenzie R, Maxwell N, et al. Heat acclimation improves intermittent sprinting in the heat but additional pre-cooling offers no further ergogenic effect. J Sports Sci. 2011;29(11):1125–34.

    Article  PubMed  Google Scholar 

  42. Cheung SS, McLellan TM. Heat acclimation, aerobic fitness, and hydration effects on tolerance during uncompensable heat stress. J Appl Physiol. 1998;84(5):1731–9.

    CAS  PubMed  Google Scholar 

  43. Daanen HAM, Jonkman AG, Layden JD, et al. Optimising the acquisition and retention of heat acclimation. Int J Sports Med. 2011;32(11):822–8.

    Article  CAS  PubMed  Google Scholar 

  44. Houmard JA, Costill DL, Davis JA, et al. The influence of exercise intensity on heat acclimation in trained subjects. Med Sci Sports Exerc. 1990;22(5):615–20.

    Article  CAS  PubMed  Google Scholar 

  45. Lorenzo S, Halliwill JR, Sawka MN, et al. Heat acclimation improves exercise performance. J Appl Physiol. 2010;109(4):1140–7.

    Article  PubMed Central  PubMed  Google Scholar 

  46. Lorenzo S, Minson CT. Heat acclimation improves cutaneous vascular function and sweating in trained cyclists. J Appl Physiol. 2010;109(6):1736–43.

    Article  PubMed Central  PubMed  Google Scholar 

  47. Nielsen B, Hales JR, Strange S, et al. Human circulatory and thermoregulatory adaptations with heat acclimation and exercise in a hot, dry environment. J Physiol. 1993;460:467–85.

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  48. Nielsen B, Strange S, Christensen NJ, et al. Acute and adaptive responses in humans to exercise in a warm, humid environment. Pflugers Arch. 1997;434(1):49–56.

    Article  CAS  PubMed  Google Scholar 

  49. Racinais S, Buchheit M, Bilsborough J, et al. Physiological and performance responses to a training camp in the heat in professional Australian Football players. Int J Sports Physiol Perform. 2014;9:598–603.

    Article  PubMed  Google Scholar 

  50. Sawka MN, Young AJ, Cadarette BS. Influence of heat stress and acclimation on maximal aerobic power. Eur J Appl Physiol. 1985;53(4):294–8.

    Article  CAS  Google Scholar 

  51. Voltaire B, Galy O, Coste O, et al. Effect of fourteen days of acclimatization on athletic performance in tropical climate. Can J Appl Physiol. 2002;27(6):551–62.

    Article  PubMed  Google Scholar 

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No funding was provided for the preparation of the paper. No author has any conflicts of interest. All authors contributed fully to the preparation of this manuscript.

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Correspondence to Andrew M. Edwards.

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Guy, J.H., Deakin, G.B., Edwards, A.M. et al. Adaptation to Hot Environmental Conditions: An Exploration of the Performance Basis, Procedures and Future Directions to Optimise Opportunities for Elite Athletes. Sports Med 45, 303–311 (2015). https://doi.org/10.1007/s40279-014-0277-4

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  • DOI: https://doi.org/10.1007/s40279-014-0277-4

Keywords

  • Elite Athlete
  • Heat Exposure
  • Heat Acclimation
  • Pace Strategy
  • Plasma Volume Expansion