As temperatures climb, the anticipation for summer youth sports begins to bubble up. Whether it’s soccer, baseball, track, or field hockey, the summer season offers young athletes an opportunity to shine and grow in their sports of choice. However, the rise in mercury brings with it a serious consideration for coaches, parents, and players: heat acclimation. Proper preparation and understanding of heat acclimation are vital to ensure not only the performance but also the safety of young athletes as they hit the fields this summer.
Understanding Heat Acclimation
Heat acclimation refers to the process by which the body gradually adapts to work efficiently under warmer conditions. This adaptation includes physiological changes like increased plasma volume, earlier onset of sweating, and a more efficient cardiovascular system that occur gradually over the course of 10-14 days of heat exposure (Figure 1). These adaptations are crucial as they help reduce the risk of heat-related illnesses, which can range from mild heat cramps to severe conditions such as heat stroke.
Figure 1: A variety of physiological adaptations that help individuals better perform in the heat (heat acclimation) occur over the course of around 14 days. Image from (Periard, et al, 2016), DOI: https://doi.org/10.1016/j.autneu.2016.02.002, used under Creative Commons CC-BY-NC-ND license.
How Much Time Is Needed to Acclimate to the Heat?
As shown in Figure 1, full heat acclimation of known physiological adaptations can take upwards of 14 days.
But this is variable. It depends on the intensity, duration, and frequency of acclimation processes. It also depends on the aerobic fitness of the individual and how recently they were heat acclimated prior to the current acclimation process.
The important thing to remember is that the heat acclimation process is gradual. As temperatures climb, ease into the process and gradually increase time and intensity of activity in the heat as your body adapts over this time period.
Some adaptations will begin immediately. Several cardiovascular changes fall into this camp, including changes to blood plasma volume and heart rate. These changes can gradually lead to less strain on the cardiovascular system during work in the heat.
Over time, other changes, such as changes to sweat rate and sweat sodium concentration gradually adapt to allow for more efficient cooling, hydration, and plasma volume regulation.
When is the Time to Worry About Heat Acclimation?
As soon as the weather starts getting hot, heat acclimation should come to mind.
For some youth athletes, they might not be all that active until the season starts. If it’s already hot outside by the time the first practice begins, they may not have put forth any efforts to acclimate to the heat.
For example, a 6-year analysis of high school football players in North Central Florida showed the majority of all exertional heat illnesses occurred during the first 19 practices. In fact, 94.4% of all heat injuries (51 out of 54) occurred during these first practices of the season. And this trend holds for youth athletes through college athletes, alike.
Why It’s Crucial for Youth Sports
Youth athletes are particularly susceptible to heat-related illnesses for several reasons. Their bodies are not as efficient at regulating temperature compared to adults. Additionally, they may not always recognize the symptoms of dehydration or heat exhaustion, making it essential for coaches and parents to monitor their condition closely.
Strategies for Heat Acclimation
Gradual Exposure: Start practices with low to moderate intensity and gradually increase the duration and intensity over 10-14 days. This gradual buildup helps the body adapt to the heat stress safely.
Hydration Plans: Implement structured hydration plans that encourage drinking fluids before, during, and after practices or games. Consider the use of electrolyte-enhanced drinks if the activity lasts longer than an hour to replace salts lost in sweat. And when practical, consider hydration testing.
Appropriate Clothing: Encourage athletes to wear lightweight, light-colored, and breathable clothing. Such gear helps with the evaporation of sweat and keeps the body cooler.
Scheduled Breaks: Incorporate frequent rest breaks into practice sessions and games. Use these breaks to find shade, rehydrate, and allow coaches to check in on the athlete's well-being.
Education: Educate both athletes and parents about the signs and symptoms of heat-related illnesses, including muscle cramps, fatigue, dizziness, headache, nausea, and changes in sweat rate or color of urine, which can indicate dehydration.
Planning Ahead
Before the season starts, it’s beneficial for teams to hold meetings to discuss strategies for dealing with heat. These sessions can include setting up hydration stations, planning the logistics of regular breaks during games and practices, and perhaps even arranging for medical professionals to give talks on heat safety.
Preparing for the summer season in youth sports is not just about strategy and skill development; it's equally about health and safety. Taking heat acclimation seriously is a critical component of this preparation. By incorporating gradual acclimation practices, staying vigilant about hydration, and educating everyone involved about the dangers of heat, teams can ensure that the only heat they battle is on the scoreboard.