Its almost summer, and that means we’re about to get to the hottest point of the year, as well as the bulk of the triathlon and cycling seasons. We’ve all experienced the monotonous trudging through the triple digit temperature days come July and August, and had that one race where it was so hot you just wanted to jump into a pit of ice. Its been widely known for a while that training and racing in very high temperatures can be dangerous, so its important to know what is going on in your body in order to avoid heat stroke or dehydration. But there are also very helpful benefits that come from heat training if done properly that can give you a pretty big advantage over the competition.
Adverse effects of Heat Training
-Your blood flow increases. Blood circulation is how your body keeps itself cool. During hot temperatures, your body needs to circulate more blood in order to cool the body and accommodate for the exercising muscles. This causes the heart rate to increase, leading to higher heart rates at any given intensity of exercise, making an 8 minute mile feel like a 6 minute mile.
-Your sweat rate increases. This is the body’s other way of cooling itself. Sweat evaporation cools the body, but also drains the blood of a lot of its plasma, the fluid in blood. The less plasma content your body has, the thicker your blood is and the harder your body has to work to pump blood.
-The heart is under more stress. This goes back to the increased circulation. The more blood your body needs, the more the heart has to pump, leading to a higher heart rate.
-Muscles blood flow decreases. This is due to the body needing to use more blood for cooling the body. That blood is the no longer available to be used by muscles.
-Dehydration occurs faster. With excessive sweat comes fluid loss. If the fluids are not properly replenished, dehydration can occur quickly.
Benefits of heat training.
-Your body becomes better at keeping cool. The human body is incredible at adapting to differing situations. The same applies to excessive heat. With proper time to acclimatize, your body will learn what it needs to do in order to not over heat. This can include sweating more earlier in exercise, strengthening the heart in order to pump more blood, or retaining sodium from sweat loss.
-Your cardiovascular function improves. Since the heart is having to work harder during exercise, eventually this translates into improved function from a lower heart rate, increased blood plasma, and increased stroke volume.
-In the long term, exercise performance improves. This is mostly due to the previous two benefits. With the increased cardiovascular abilities and more efficient cooling, performance increases similarly to altitude training.
But how long does it take for these benefits to actually start helping? Usually it takes about 2 weeks, although each athlete is obviously a little bit different. Most research has shown that 10 days of training at low intensity in high temperatures can induce these responses. In order to acclimatize, spend these days working at very low (somewhere in the 60-70% range) intensities while taking a day off every 2 days in order to let your body recovery from the added stress. In most cases, volume will have to decrease at least a little bit depending on the athlete’s fitness. This can also be done indoors or in otherwise cooler climates by wearing excessive clothing or during the thermostat up. Just make sure you continue to hydrate properly as your body will be losing a lot more fluid to sweat.