A year of training can quickly be erased if an athlete is not properly prepared for the expected weather conditions on race day. Often, the final weeks of a triathlon season include many big events—such as Ironman Hawaii, XTERRA Maui, Great Floridian, Ironman Western Australia—held in hot, humid.
Since few of us have the luxury of putting our jobs and lives on hold and traveling to our key late-season event several weeks early to acclimate, here are 10 guidelines that will help you to conquer the heat and realize your full potential on race day.
1. Boost Your Fitness
The best performances in the heat tend to come from the athletes with the best fitness. The effects of the heat are exponentially multiplied when an athlete's physiology is already struggling with the workload. Even under the best conditions, heat production in the muscles increases with the intensity of activity.
Arriving at the starting line in a state of peak fitness will not only set you up for maximum performance, but it will also enable you to manage heat stress better through greater efficiency (hence less heat produced at any given pace) and high blood plasma volume (hence a greater ability to transport heat away from the muscles). These factors lead to a lower core temperature, thus minimizing heat stress and discomfort.
One of the best ways to acclimatize is to travel to your race location well in advance of your event. But this involves added expense and time away. Fortunately, you can acclimatize to almost any environment from your home.
Start at least three weeks before your event by doing regular 60- to 90-minute indoor sessions of biking or running at a low to moderate effort. Turn up the heat, limit the airflow and, if possible, add a humidifier. This will elevate your core temperature, resulting in an increased sweat and heart rate.
Do this for five consecutive days, then, over the course of the next two weeks, be sure to repeat the session for at least 30 minutes, twice per week. It is possible to achieve the same effect outdoors but you will have to wear additional layered clothing with a warm hat.
The results of heat acclimation seem to be cumulative, so if you have the opportunity to train in the heat earlier in the year at home, at another hot venue or at your race site, it should help you in the long term.
3. Determine Your Sweat Rate
Calculating your sweat rate is the most effective method of determining how much fluid you are losing and need to replenish. You may find that your sweat rate is different depending upon the discipline, effort level and environmental conditions. You should try to simulate the environmental conditions of your key race and your race effort.
In order to determine your sweat rate, weigh yourself without clothes before and immediately after exercise and account for any fluid consumed. An accurate scale will be required, and you will need to avoid going to the toilet until the measuring is completed. The simple formula to calculate sweat rate is as follows:
- Your weight prior to the exercise = A lbs.
- Keep track of the amounts of fluids you consumed during exercise = B oz. consumed.
- Weigh yourself upon completion of the exercise = C lbs.
- Determine weight lost during exercise = A - C lbs. x 16 = D oz. lost:
- Account for fluids consumed to determine your total sweat loss: D oz. of fluids lost + B oz. fluids consumed = E oz. of total sweat loss.
- Divide E (ounces of total sweat loss) by minutes of exercise for sweat rate per minute of exercise = F oz./minute of sweat loss
Body fluids such as blood are made up of mostly water and electrolytes. Muscle is comprised of 75 percent water; therefore, it should come as no surprise that a loss of two to three percent of bodyweight due to sweating can significantly reduce athletic performance.
It has been well demonstrated that triathletes, when training or racing, only replace about 50 percent of fluid losses; thus, despite our best efforts, slight dehydration is unavoidable in some circumstances.