Heat Training

Over in the Twitterverse, I happened upon an article in Trail Runner Magazine (apparently a similar one appeared in Outside; both reference an NIH study) discussing the blood benefits of heat training.

As a lifelong resident of south Texas and its glorious heat & humidity, I can certainly say that I’ve loved riding & running in the heat. However, as I’ve aged—and, sadly, gained weight, (I’ll turn 47 next month & weigh in at 182 lbs/82kg), such enjoyment of heat has waned. At least somewhat.

My initial thoughts was that declining performance in heat had to do with age & weight, but the NIH study indicates that cyclists studied were all in the same range as I am. Other thought? My wife’s MS symptoms demand that we keep the house a frigid 68° F (20° C) year round, which, I can see, impacts my own performance in & out of doors.

While this isn’t exactly SUF-related, anyone have similar (or drastically different) reactions to temperature fluctuations?

I will turn 50 in a few months with 83kg. Living in South America (South of Brazil) is not hot as Texas, but as you mentioned in recent years I struggle more in hot days, need more time to adapt to the increase of temperature when summer comes, on the other hand our winter is not so severe (never had snow days) temperature AVG in winter 10° C and feel easier to cycle.

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Thank you for your question about heat training.

While there are a lot of positive physiological adaptions to heat training (as discussed in the articles you linked), exposure to air conditioned environments does have an impact on those adaptations. This abstract discusses a study that looked at the thermal comfort responses of 2 groups of people: one group that was acclimatized to a naturally ventilated environment and one acclimatized to an air conditioned environment. The results showed that the group acclimatized to the naturally ventilated environment (no air conditioning) felt less discomfort in the heat than those who spent more time living and working in the air conditioning. While the physiological mechanisms aren’t discussed in this abstract, it is suggested that consistent or long term exposure to air conditioning does weaken your physiological adaptability to the heat. So the advice I’ve heard time and time again when going to an event in a hot environment not to use the air conditioning, except when sleeping at night (in order to get higher quality sleep), does hold up to research. So in a nutshell, I would agree that the temperature of your home is affecting your response to the heat. And while I cannot back this up with research, I would also propose that the aging process also affects your response to the warm temperatures, in a similar way that older people begin moving south in the winter because they can’t tolerate the cold as well as when they were younger. I believe the same is true for heat, and the simple fact that as we age, we don’t tolerate extremes as well, on either side of the temperature gauge.


Dame Suzy,
First, thank you for the reply. It—and the provided abstract’s conclusion (“it appears that long-term exposure to stable AC environments may weaken people’s thermal adaptability”)—confirms what I had been fearing: My overall health & fitness have both declined as a consequence of my house’s temperature. Layering is not practical, and raising the thermostat is not possible as the latter would more severely affect my wife and her health.


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I was thinking of moving my trainer indoor into the A/C. I live in FL and have my pain cave in my garage with multiple fans to help cool me, overall the humidity is well over 60% and the temp ranges from high 80s to mid 90s during my trainer rides. sometimes it can be brutal. I do not want to loose any heat tolerance by switching rides indoors. thanks for posting the above response.

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This all comes down to what you are training for, if you are training to race in the heat then you need to train in the heat, if you are training to race somewhere chilly your training should reflect that. Ultimately if your body is having to work harder to keep cool or warm up in the pain cave it will have less capacity to push out the Watts for cycling so finding a balance is important here. Personally I try and mimic race conditions for the majority of indoor rides and then make the temperature a bit cooler for any tests e.g. full frontal :slight_smile:


In South Texas, one really has no choice but to train in the heat. :wink:

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