FEATURE: HEAT STRESS HEAT ACCLIMATISATION FOR THE2018 FIFA WORLD CUP disrupting the fi nal preparations of Heat training a team, a re-acclimation approach may be utilised. This would involve an initial 7 to 10-day heat acclimation camp Heat acclimatization Heat acclimation performed 4-6 weeks prior to traveling, Natural environment Artificial environment followed by a 3 to 5-day re-induction (outdoor/field training) (indoor/laboratory training) phase a week before departure for competition. This approach stems from a recent review highlighting that the rate Self-paced Constant work Passive Controlled Controlled of decay in adaptations (i.e. heart rate exercise rate exercise heating hyperthermia intensity and core temperature) was /home/webapps/asp_au/data/asp/publications/au-sports-medecine-australia/publications/sport-health-volume-36-june-2018/sport-health-volume-36-issue-12.5% for Post-exercisetemperature Passive and/or activeheating each day without heat exposure, and maintenance that heat re-acclimation induced adaptation much faster than the initial Activity: Football, or runningExamples Activity: Cycle ergometer, orExamples Activity: Water immersion, orExamples Activity: Resting and/orExamples Activity: Cycle ergometerExample acclimation when undertaken within a Work rate: Variable, or self-selected marchingWork rate: 60% VO2max(185 sauna bathingTemperature: Water 40-42ºC, exercising to maintain coretemperature at 38.5ºC Work rate: 65% VO2maxheartrate (145 bpm) month (Daanen et al., 2017). Conditions: Variable outdoor, W), or 6 km/h or sauna 70-90ºC Work rate: Variable Conditions: 40ºC, 40% RH or indoor 40ºC, 40% RH Conditions: Indoor 40ºC, 40% Duration: 45-60 min, or Conditions: 40ºC, 40% RH Duration: 60-90 min Duration: 60-90 min RH, or variable outdoor intermittent for 30 min Duration: 60-90 min Ultimately, the ability to perform at an Duration: 60-90 min optimal level during soccer tournaments held in hot ambient conditions, such as Figure 2. Schematic overview of methods to induce heat acclimatisation and heat acclimation the 2018 FIFA World Cup, is a function with examples of diff erent activities to employ. Diff erent combinations of temperature and relative of acclimatisation status and the ability humidity are possible, as well as the use of portable heaters and wearing additional clothing. to recover between matches. Whilst RH: relative humidity; VO2max:maximal oxygen uptake. Adapted with permission from there is some evidence that heat (Daanen et al., 2017). acclimatisation may enhance exercise capacity in cool environment, there no evidence to suggest that it impairs cool weather performance. Therefore, acclimatisation is suggested to provide environmental conditions the team given its impact on exercise capacity more specifi c adaptations due to the is predicted to play in during the in the heat and its role in reducing the specifi city of the environment in which tournament. This might involve arriving risk of exertional heat illness, heat the athletes train and compete (e.g. early to the tournament destination in acclimatisation is a strategy all national temperature, humidity, solar radiation). order to have a su ffi cient amount of time teams should contemplate utilising. to adapt and recover from travel. Given The physiological adaptations related to that teams may play in diff erent cities REFERENCES repeated heat exposure develop quite throughout the World Cup, it would be rapidly with 75-80% of the process advisable to spend a week or two in the Daanen HAM, Racinais S & Periard JD. occurring in the fi rst 4 to 7 days, but city most likely to off er the strongest (2017). Heat acclimation decay and requiring 10 to 14 days to be completely stimulus for adaptation. Alternative re-induction: a systematic review or near-completely acquired (Figure 1). approaches would be to passively heat and meta-analysis. Sports Med. The rate at which these adaptations acclimate by spending time in a sauna develop is dependent on the protocol or hot bath after practising in cool Horowitz M. (2014). Heat acclimation, employed, with a variety of strategies conditions, or to heat acclimate in epigenetics, and cytoprotection memory. on off er (Figure 2). For soccer teams, an environmental chamber at a controlled Compr Physiol 4, 199-230. the most appropriate strategy would intensity (i.e. heart rate), or by conducting be to utilise the self-paced approach a more specifi c repeated-sprint Mohr M, Krustrup P & Bangsbo J. (2003). and conduct training in the outdoor protocol. In order to avoid excessively Match performance of high-standard 24 VOLUME 36 • JUNE ISSUE 2018