These guidelines, on the recommendation of the MHSAA SMAC, were approved by the MHSAA Executive Board.
The 14-Day Heat Acclimatization Period
The heat-acclimatization period is defined as the initial 14 consecutive days of preseason practice for all student athletes. The goal of the acclimatization period is to increase exercise heat tolerance and enhance the ability to exercise safely and effectively in warm and hot conditions. This period should begin on the first day of practice or conditioning, prior to the start of the regular season. Any practices or conditioning conducted before this time should not be considered a part of the heat-acclimatization period.
Regardless of the conditioning program and conditioning status leading up to the first formal practice, all student athletes (including those who arrive at preseason practice after the first day of practice) should follow the 14-day heat-acclimatization plan.
Consensus Statement Recommendations
The consensus statement lists seven key recommendations for a 14-day heat-acclimatization period prior to full-scale athletic participation by secondary school students, as follows:
1. During the first five days of the heat-acclimatization process, athletes may not participate in more than one practice per day.
2. If a practice is interrupted by inclement weather or heat restrictions, the practice should recommence once conditions are deemed safe, but total practice time should not exceed three hours per day.
3. A one-hour maximum walk-through is permitted during the first five days of the heat-acclimatization period; however, a three-hour recovery period should be inserted between the practice and walk-through (or vice versa).
4. During the first two days of the heat-acclimatization period, in sports requiring helmets or shoulder pads, a helmet should be the only protective equipment permitted (goalies, as in the case of field hockey and related sports, should not wear full protective gear or perform activities that would require protective equipment). During days three, four and five, only helmets and shoulder pads should be worn. Beginning on day six, all protective equipment may be worn and full contact may begin.
5. Beginning no earlier than the sixth day and continuing through the 14th day, double-practice days must be followed by a single-practice day. On single-practice days, one walk-through is permitted, but it must be separated from the practice by at least three hours of continuous rest. When a double-practice day is followed by a rest day, another double-practice day is permitted after the rest day.
6. On a double-practice day, neither practice’s duration should exceed three hours total, and student-athletes should not participate in more than five total hours of practice. Warm-up, stretching, cool-down, walkthrough, conditioning and weight-room activities are included as part of the practice time. The two practices should be separated by at least three continuous hours in a cool environment.
7. Because the risk of exertional heat illnesses during the pre-season heat-acclimatization period is high, the consensus statement strongly recommends that an athletic trainer be on site before, during, and after all practices.
In addition to NATA, the task force that developed the consensus statement comprises seven other groups, including American College of Sports Medicine, Gatorade Sports Science Institute, National Strength and Conditioning Association, United States Army Research Institute of Environmental Medicine, American Orthopaedic Society for Sports Medicine, American Medical Society for Sports Medicine and American Academy of Pediatrics. For more information, please visit www.nata.org.