Triathlon Racing in Hot & Humid Conditions
Racing in Hot & Humid Conditions
Article by Daniel Bain
Most professional athletes have the opportunity to arrive at their race destination a fortnight before a major race and acclimatize to the new conditions. However, most age group athletes don’t have this luxury and have to do the best they can to acclimatize in a short period of time.
This article below is a guide for any athlete who is racing in a hot and humid destination and only has a short time to acclimatize.
What happens to your body when you race in heat and humidity
Firstly, if you’re racing in hot and humid conditions, don’t expect to be able to perform to the same standard as in a cool climate. Most world records are set in mild conditions for a reason – the body copes better when it’s not overheating. Below are some key physiological functions that will change in hot conditions - mostly as a result of your body trying to keep itself cool;
- Your heart rate will be higher than usual
- Your core temperature and skin temperature will rise
- The rate that your body uses glycogen (sugar / carbs) as a fuel source will be higher
- Your blood lactate levels will be higher
- Your sweat rate is higher than usual
- The salt content in your sweat is higher
All of the above functions on their own will not necessarily hinder performance as long as your body can prevent itself from overheating. However, when an environment is hot and humid, a cascade of events occurs that can cause your body to overheat and performance will suffer. That cascade of events is simplified as follows
- Your core body temperature and skin temperature rise so you begin to sweat
- Normally your sweat would evaporate which cools your body down. However in humid conditions, the sweat cannot evaporate easily as the air is already dense with evaporated water.
- The sweat accumulates on the surface of the skin
- The sweat on the surface of your skin is heated up by your increased core body temperature and skin temperature.
- Your body tries to cope by sweating more but cannot evaporate effectively and your core body temperature rises further.
- The cycle continues…
Following this series of events, your body initiates protective mechanisms in the form of thermoregulating hormones and neural pathways to prevent you from overheating and causing cellular damage. The net effect for you as an athlete is that you cannot cope and you are forced to slow down.
What can you do to acclimatize to race conditions
Understanding what is happening to your body during hot and humid conditions allows you to formulate a plan to cope with the conditions. Below are some tips to help you adjust
Leading up to race day
- Arrive at your race destination as early as possible. Research suggests that you need about 5-8 days to fully adjust to the new environmental conditions and the longer, the better.
- Ensure you stay hydrated during your flight to prevent dehydration from the low humidty conditons on the plane. Ideally select a drink that contains electrolytes such as a sports drink to avoid dehydration and loss of salts prior to arrival.
- Expose yourself to the heat and humidity early – don’t hide in air conditioned hotel rooms
- Drink plenty of water and frequently to make up for the increased sweat rate
- Consider taking salt supplements (Magnesium, Calcium & Sodium) in the weeks leading up to your race to prepare for the increased salt loss in your sweat on arrival. Maximising your intra-cellular salt content should also help prevent heat / sweat related cramps during the race. Also note that the longer the race is, the more focus you should place on salt supplementation. Ironman Kona has a greater chance of salt related cramps than a sprint triathlon race.
- You don’t train in the middle of the day to acclimatize, train when it is cooler but make sure that you still experience the conditions during the day. Acclimatization occurs gradually and there is no need to dehydrate yourself to try to make it happen faster.
Immediately before the race
- Stay in a cool place before the race until its ready to prepare for the race. Minimal exposure before the race is always better.
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Ensure you sip a drink that is very cold to assist in reducing core body temperature before race start.
During the Race
- Race in appropriate materials that assist your skin to evaporate the sweat
- Put a cold or semi frozen bottle of water on your bike and use the drink to help cool your core body temperature during the race. There are studies currently being conducted in Australia testing the effectiveness of “slushies” prior to racing to work as a heat sink. Overheating is a key factor in sporting performance and any help to reduce your core body temperature may assist performance.
- Cool your gels in the fridge so they are not warm on race day.
- Have a cold / half frozen bottle of water in transition to poor on your head to cool you down in T1 & T2
- Throw plenty of water over yourself from the drink stations during the race. The water from your sweat is at 37 degrees Celsius or higher. The water from the stations should be lower and you can displace your hot sweat with cooler water.
- Wear a visor, not a cap. Give the heat from your body the best chance to escape from the top of your head.
- Ensure you drink a sports drink which contains appropriate salts to replace those lost in your sweat. For endurance races over 2 hours or if you are prone to cramping, consider taking salt supplements such as saltstick or hammer endurolytes during the race.
There are a lot of things you can do in preparation for racing in hot and humid conditions. The best approach you can take it is to formulate a racing strategy that incorporates all of the above factors with a pacing strategy that minimise your chance of overheating and maximises your chance of a great performance.
