It’s easy to get overwhelmed when you start the journey into heat training, as there’s a lot of conflicting information in how to train for the heat. Heat is a physical stressor that you have to adapt to and accommodate in your training plan. Here’s how to train for the heat if you’re an athlete. Many athletes need to perform in hot conditions.
It’s important to find out how many units/stress inputs you can handle before trying to take on too much. This means that if you can only handle 10 units of heat per day, then don’t try to add 2 or 3 units to a 9 unit workout. This is just a recipe for disaster. On the other hand, if you have an easy 2 unit workout day and want to add 3 more units, then go for it.
Determining the best protocol for your personal needs and taking into consideration the time you have are two key factors we’re diving into with Dr. Steven Cheung.
Who Is Dr. Steven Cheung?
Dr. Steven Cheung is a wealth of knowledge on the topic of environmental physiology, and an avid cyclist himself. He’s worked with people like Amber Neben, helping her train for the heat of the Olympics. He’s a professor in the department of kinesiology at Brock University. He is also an author of the textbook Advanced Environmental Physiology.
If you’re not familiar with the topic of environmental physiology, it expands far more than just heat training. It encompasses all the different environmental elements that could affect your performance, like, for example, how your health is affected by hot conditions, cold conditions, different altitudes, or even when you’re underwater. Dr. Cheung worked with the Canadian national team in preparation for the 2020 Olympics in Japan, where it was hot and humid.
Before we cover proper protocols for heat training, it’s important to understand how our body reacts and responds to stress from heat.
How Our Bodies Get Rid of Heat
The human body has four main ways of getting rid of heat. The first three include Radiative, Conductive, and Convective heat loss, which are what we call “dry heat exchange.” These rely on the difference in temperature between your body and the environment. The fourth way is Evaporation (also known as sweating). This last one relies more on the water vapor pressure gradient, or the amount of humidity in the air, rather than the temperature gradient.
There’s a big difference between dry heat and hot or humid conditions, with the latter being much more challenging. Not only is your dry heat exchange impaired because of the high temperatures, but the air is also so saturated that you are sweating more. Since the air can’t hold any more vapor, then the sweat is not evaporating anymore. Both of the dry and wet pathways are being impaired in this scenario.
Preventing and Addressing Heat Stroke
How can an athlete realize when heat stroke or heat exhaustion is imminent, specifically when on a bike? Also, what should you do if you find yourself in this situation?
Heat illness encompasses a wide range of symptoms and pathologies, but at the most basic level, your body is telling you that it’s too hot. There’s no single threshold or core temperature that is dangerous for everyone, but there is a physical maximum: 42-43 degrees Celsius. When you reach this point, your cells just start breaking down.
But beyond that limit, in terms of the mind and body, how much can someone handle? A lot of it comes down to individual background and your climatization state.
Typically, you’ll find that the fitter you are, the more acclimated you are, and the higher core temperature you can handle. On the mental side is the perception of effort, being able to deal with that discomfort. So, when is it that perception falters and we start slowing down?
Everybody has a limit, and there is no way of pushing yourself beyond your individualized physical limit. For most of us, there is a big gap between the “warning zone” (where you start feeling really uncomfortable) and the “danger zone” (where you’re at true physical danger).
Think about it like the gas gauge in your car. If you’re driving along and the gas gets low then the warning light comes on. That’s your first sign. Some of us continue to drive, push things to the limit, and nothing happens. Others take that first sign to immediately get gas.
This is where the mind comes in. All the feedback you get from your body, as well as your experience (especially if you’ve had a really negative experience with heat stress or heat stroke before), will impact your decision-making. A lot of the interventions below are just adjusting psychologically.
Our first intervention, or technique, is using motivational self-talk during the period where you’re trying to climatize.
Whenever things are really hard and capabilities are being pushed to the limit, looking for something positive to hang on to can help you get through it. If it’s been a positive experience, you have the additional confidence that pushes you to perform in a certain way.
Focus on small steps. Think about the little victories you can achieve. Everyone’s coping strategies are different. Some may need to yell and hype themselves up. Others might look for those small victories.
To improve your motivational self-talk, check out my Mindset Academy.
Acclimation of climatization is more about physiology. Habituation on the other hand is more about psychology. Both of these fall under the umbrella term of adaptation.
From the physiological side, there’s a lot of different protocols out there. Some say you only need 5 to 7 days, and then to use the sauna after a workout. Some say you need to dehydrate yourself.
Dr. Cheung’s Tips: How to Adapt for Heat
Getting the core temperature as high as 38.5 Celsius is the main stimulus needed to adapt the body and keep it going for a decent period of time (a minimum of an hour to 90 minutes a day).
The body doesn’t register or care how you get hot, so it’s not necessary to worry about “the ideal heating method.” The main thing is to get your body warmer than normal and to keep it warm.
There have been very effective acclimation protocols that only require 4 to 5 days, but longer times are oftentimes better. This is the minimum needed to see adaptations, things like a lower heart rate and lower core temperature. However, you’re not really going to start seeing sweat rate improvements until close to the second week.
If you really want to maximize your adaptation, you’ll need 10 to 14 consecutive days of the chosen stimulus. The simplest way when you have limited resources is to train while wearing more clothes.
Another way is with passive exposure. This could be sitting in a sauna, sitting in a steam room, or using a hot tub. This process takes much longer and the body doesn’t like it as much, which means it will consistently try to get back to normal temperatures. Sitting in a sauna for 30 minutes, without doing any exercise, isn’t nearly as effective. The most effective way to use passive heat exposure is by exercising first and then immediately using a sauna or other passive exposure source.
Remember that heat is an additional stressor on your body that goes above and beyond your training. This means that if you’re already doing a super hard workout and you add heat to it, then you are just compromising your actual training.
Instead, layer on the heat. Use adaptation techniques on those longer, easier rides where you’re just putting in the time and the stress is lower.
The good news is that any type of heat adaptation, whether it is a sauna or steam room, will get you heat-adapted.
The only study on these differences was by an Israeli researcher in 1997, where she looked at three types of heat adaptations. First, a hot and dry heat. Second, a warm and humid adaptation. Finally, normal room temperature with a high solar load. After two weeks of training, she mixed up the groups so that they would experience one of the other climates. When it was all said and done, the participants adapted equally well to any condition.
This leads us to highlight the importance of getting and keeping your body hot to get the results you are looking for.
In the humid heat, you’re going to sweat a lot more, and that’s the main stimulus that you want.
Heat Training Upkeep
How long do the benefits of heat training last before they start to diminish?
Heat training is not like altitude training. If you go train at a higher altitude, your body responds by making more red blood cells. Coming back to sea level with the extra red blood cells gives you an edge. With heat training, studies lean towards finding no difference in increased performance once you return and stay in the cooler environment.
To keep up your heat-training performance gains for a month or more, you need one heat stimulus every four to five days. The reality is that keeping these gains is more of a logistical challenge involving when to schedule it, how best to schedule it, how to schedule it during your taper, and how it’s going to affect your recovery, to name a few.
Considerations for Female Cyclists
Does heat adaptation for women work differently? During the menstrual cycle and hormonal changes, your body can deal with heat in different ways. Should there be any difference in the protocol for women?
Truthfully, there’s relatively little research done on this subject and females, especially concerning heat adaptation studies. Looking at the thousands of participants in these studies, 8% were female. That’s a huge gap.
In general, hormones during the menstrual cycle affect the fluid retention pathways, gastrin and vasopressin levels, and more. Females do not seem to respond differently, but again, data on the subject is very limited.
If you’re an athlete interested in designing a training program to adapt to hot, dry, or humid environments, keep in mind Dr. Cheung’s advice and research.