I think I would be right in saying that occasionally we all experience the detrimental effects of heat when riding the bike or running in the afternoon. Thirst almost becomes an agony and we find ourselves covered in sweat and dripping water all over the place. We feel fatigued early on, even if it is supposed to feel easy, and the acute strain often makes us stop. It’s not a nice feeling and we doubt about our ability to exercise at optimum during summer time when days are warm and triathlons are often raced in the middle of the day.
But why does our body suffer when we exercise in the heat? During exercise in the heat our body uses more glycogen (stored energy used when exercising at higher intensities together with carbohydrate and fat) increasing carbohydrate (CHO) oxidation and lactate accumulation. We also lose a great amount of water, thus becoming dehydrated in early stages of our exercise, which impairs our exercising capacity notably. We also lose electrolytes through sweat such as Sodium (Na+) and to a lesser extent potassium (K+), Calcium (Ca2+) and also Magnesium (Mg2+) which we need to replenish as soon as possible. Without those our body would not be able to function properly as the internal body balance is seriously affected.
When you are out there working at moderate to high-intensity exercise in the heat you can easily get sweat rates of 1 to 2.5 litres per hour! It is advised that you need to drink 1.5 times the fluid lost during exercise, therefore it is crucial to be well hydrated before the training session and to drink regularly during it, even before we start feel thirsty. The stimulus to drink does not occur until after losses of 2% body mass occur. The exercising capacity is reduced after an individual is dehydrated by 1-2% body mass. This means once we start being thirsty it is too late already!
The good news is we can fight the heat! We can use the heat to make our opponents weak and take advantage over them in strenuous climate conditions where humidity and temperature are over 50% and 25-30°C respectively. We can’t change the climate, so let’s change our bodies!
Are you preparing for a race overseas or in the summer but the weather outside is still cold and rainy? A heat chamber is your solution. You don’t need to have a sophisticated heat chamber at home, all you need to have is a bathroom spacious enough to stick a heater and your bike in! The heater will take care of the temperature. Set your bike on the rollers or trainer and you are ready to go! 7 to 10 sessions in this environment of about 1 to 1.5 hours each will get you sorted for the heat and you will be ready to kick your opponents (and the heat) into touch!
Start with an easy session first and then build up the intensity as you go along. The last couple of sessions should be done at a higher intensity, but you will feel a lot better than the easy sessions you did when you first started out. Your heart rate will rise up during the first sessions by up to 15 beats per minute. This will gradually come down to the heart rate values you would have outdoors for the same working intensity. Towards your final session you will see and feel the benefit from sweating more, as this helps to cool your body down avoiding the core temperature to rise dangerously, therefore preventing you from reaching exhaustion faster than normal. Your sweat will mainly be water at this stage as your body will learn how to keep in the electrolytes that are so important for you to sustain.
So here are the six golden tips for your preparation to exercise/race in the heat:
- Drink enough before exercise and continue to drink during your work out. Try to have a water bottle in hand at all times.
- Have a sports drink ready at the end of the session as this will help to refill fluid and electrolyte losses.
- 3 to 4 weeks prior to the race start wearing a layer or two extra when going for a run or a bike ride so you get used to feeling hot and sweaty.
- Try to accumulate 7 to 10 sessions in the heat by keeping the bathroom (or similar small room) warm and getting some steam from the hot water. Don’t worry about the humidity factor if this is not going to be an issue for your race if it’s in the UK. Remember, you need be warm but you need to be able to exercise fairly comfortably!
- Drink plenty after the session to recover. You will feel you need to drink less and less during the training sessions over the time. That’s a good sign!
- A salty snack will always help to get some lost salt back into your body. You could also try to add a little of extra salt to your usual meal before and after the training session.
Some of our best athletes will be following some of these tips to get ready for Beijing! If it is good for them, it is good enough for the rest of us!
Naroa Etxebarria is the English Institute of Sport physiologist working with British Triathlon at Loughborough University. Having worked with British Triathlon during 2005-2006, Naroa spent a year at the Australian Institute of Sport working with a wide range of sports which included spending three months working with the Australian Triathlon team over in Europe. Currently employed by the EIS since November 2007, Naroa works exclusively with triathlon and the World Class podium and development athletes at the Loughborough High Performance Centre.