Sauna and Heat Training

Triathlon is a warm weather sport, and right now in Canada it is not that warm. Certainly not warm enough to undergo any sort of heat adaptation, or to maintain any adaptation that may have been gained over the summer. One thing I learned last year is that after enduring an entire Canadian winter with no thought given to heat adaptation, I did not perform well in the heat- at least not over long distances.  The reason I make the distinction between performing well over long / shorter distances is because I performed decently well in Galveston 70.3 on April 26th, and then just three weeks later I had a total melt down on the run at Ironman Texas on May 16th, which took place about 1 hour north of Galveston.

I found this to be a bit surprising because I’ve always enjoyed the heat- both racing and exercising in it. The reason for the melt down at Ironman Texas was likely not solely due to heat adaptation- for instance, I was consuming about 750mL per hour of fluid, and sweating at well over 2L per hour- but I do believe heat acclimation certainly played a role. From that race onwards I began tinkering with ways to adapt to and lessen the stress of racing in the heat. Here is where my thoughts on the topic currently stand:

  1. Consistency is key. Doing one or two sporadic heat acclimation sessions will not lead to any significant adaptation. Training for the heat is similar to training in general; if you provide a regular stressor, the body will eventually find ways to adapt to and lessen that stress.
  1. Sustainability is key. In a way, this is related to the first point. When training for Kona last year I went gung-ho into my heat training and cranked the heater and humidifier as high as they would go, shut the door and all the windows, and put a towel in all of the cracks where heat could be lost. I did a few sessions that lasted five straight hours in these conditions. I would then get into a sauna at 130-140F. It was so taxing on my body that I had mild heat stroke. I was sitting in the sauna, head feeling like it was going to explode off of my body, and yet my skin was bone dry. I also began developing a rash on my chest, arms and legs. That kind of training is not sustainable and not necessary. A much better approach would have been to incorporate a bit of heat towards the end of an easy ride / run or workout, and then get into the sauna.
  1. Significant adaptation can be made using a sauna. There have been a few studies recently to show this, which can be found HERE and HERE, and then of course I have my own anecdotal experiences. After just a few sessions in the sauna my ability to endure exercise in the heat had improved noticeably. I found a cheap used sauna on a local buy and sell website, and it is one of the best purchases I have ever made.
  1. The sauna is best used once your core temperature is already elevated. Quite frankly, I think the sauna is a waste of time if your core temperature is not already elevated significantly. It is best to get into the sauna immediately following one of your heat sessions on the bike or run. From what I can tell, in order to experience the gains from a sauna, your core needs to get to temperatures that the body does not experience often. This can literally take hours if you have not already elevated the core beforehand. Another method is to exercise in the sauna, but I do not think this is necessary. The training you will do in the sauna will be nothing but junk mileage, but it will be massively taxing from a perceived exertion standpoint. Instead, I recommend cranking the heat up in your training room for the final half hour of your Endurance ride, perhaps even turning the fan off, and then get into the sauna for 20-30 minutes. If done properly, the sauna will be very challenging, without doing any exercise in it.
  1. Don’t sacrifice quality for heat training. This is a mistake I made last year that I will not make again. I started doing ALL of my workouts in the heat. If you’ve ever exercised in the heat, you will know that all of your run paces and bike wattages will decrease markedly at constant perceived exertion, or constant heart rate. If you spend several months training in the heat, and never really pushing your upper limits (Vo2Max and Lactate Threshold) then those values will begin to drop. Sure, you may be better in the heat, but you have also detrained; and it is possible that these may occur in relatively proportional amounts. Instead, I suggest using your Easy / Endurance rides and runs to work on heat training, or your final couple of intervals in a workout and your “cool down”.
  1. The principle of specificity still applies. One of the mistakes I made in my heat training for Kona last year is that I was running with two big fans blowing on me. When I got to Kona I was dismayed to find that there was literally NO wind on the run course. If you are training for Kona, then I highly advise incorporating some run sessions in high heat, without a fan on. But I do not advise this on the bike. It is plenty windy on the bike course, so there is no need to improve your ability to ride a bike in high heat with no wind. There has been much written about many of the major races out there and I suggest learning the idiosyncrasies of the race you are training for, and create a heat training protocol that is in line with the demands you will face.
  1. Start slow, and keep a bit of heat training in your weekly routine, year round. If you are like me, and performing well in a very hot and humid environment is your goal, then you need to become a master of the heat. You don’t necessarily need to do a strict heat training routine year round, but I definitely recommend putting your heat training into a “maintenance mode” even if no hot races are on the immediate horizon. A big piece of performing well in the heat is psychological, and having one or two short little heat sessions per week can do a lot to keep your “heat suffering muscles” from atrophying. As well, in the name of sustainability, it is best to start your heat training slow and relaxed. For the first few sessions I would do nothing more than shut the door and turn the heater and humidifier on for your cool down. Once you start to build a little adaptation then you can slowly incorporate a bit more stress.
  1. Do not underestimate the psychological component of exercising in the heat. After Muskoka 70.3 in 2013 Andreas Raelert told me that he thinks “Kona is 90% mental.” At that time I really had no idea what he meant by that. Now that I have been there and competed, I am starting to get a sense of the meaning of that statement. You have a great deal of control over your internal workings. Meditation masters have known this for millennia. By consciously controlling your breathing you can reduce your heart rate and keep your mind from anxiously wandering. This same principal applies while exercising in the heat, it is just exponentially harder to apply. For instance, yesterday I spent 20 minutes in the sauna at 135F. Immediately before getting in I had run the final 10k of my 28k long run at about 30C and 70% humidity, with nothing but a light treadmill fan blowing. After 5 minutes of sitting in the sauna my heart rate was 107BPM. Through conscious control and focus on the breath, I was able to reduce my heart rate to 97BPM by the end of the 20 minute session. The lessons learned in the sauna can then be applied during active exercise.

In summary, heat training is very similar to training in general. You want to do the least amount of work to see the biggest gains possible. It is a balance between pushing big power on the bike and running fast, while still providing a stressor that will force the body to build machinery that will allow you to perform well even when hot. The best advice I can give you is to log everything you do, as well as how you perform. Then over time you can use this data to develop a protocol that works best for you.

Those of you living in warm climates year round can disregard this post. Thanks for reading!

2 thoughts on “Sauna and Heat Training

  1. Lionel,
    Its always interesting to read of your journey and evolution as a triathlete. In terms of the heat acclimatization I think you could fine tune your approach further still in order to do the least amount of work to see the biggest gains possible.
    Back when dinosaurs roamed the earth !! my approach involved sweat taste tests and using a thermometer where the sun don’t shine in order to monitor my adaption when preparing to race in extreme heat conditions. Primitive but effective none the less. I am sure with the help of your connections at Infinit and Guelph University they could help you develop a modern version of this approach based on the latest research. Raising your core temperature by specific amounts while training and assessing your bodies ability to adapt, and hold onto, its electrolytes stock was, back in the day, key to heat acclimatization. Whether that’s still the case now or not, I don’t know, but the likes of Darcy will no doubt be able to help you fine tune what you are doing.
    Best wishes

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