Hey forest freaks,
As the temps climb up near the 90s here - holy cow! - I've been feeling the heat in my afternoon runs. Thought it would be useful to re-post my article from last autumn reporting out on heat conditioning! There are a lot of myths out there about women being unable to acclimate appropriately to heat - and that is simply not true.
Lotsa links to scholarly articles in here so go down that rabbit hole.
On April 20th, 2017 I took my first shirtless run of the season. On May 2nd, 2017 I told my IG followers that I was going to undertake purposeful heat training for the summer. On September 18th I next wore a shirt on a training run.
This was a hot summer. I clocked over thirty runs at temperatures exceeding 95F - ten in a row over 100F. Adding to the heat was the impenetrable smoke which forced me to wear a ventilator on runs through all of August and part of September. The ventilator, much as it did an excellent job of filtering the smoke, also acted as a hypoxia-inducing mechanism by limiting the in-flow of oxygen as I went.
I'll back up and also confess: I have historically loathed the heat often telling friends and clients I'd rather be hypothermic than even a little warm. However, after choosing the Methow Valley as home, I had to befriend the heat if I intended to keep running - and I intend to keep running.
So back in May I suspended my loathing of the heat long enough to devise a loose program of heat acclimation intended to increase my tolerance. As I researched how to acclimate to heat, I found a litany of other benefits of heat training: increased tolerance of cold, increased VO2Max in hot and cold conditions, and training adaptations similar to those I have experienced at altitude. The mechanism for all these useful changes? Increased plasma volume (a la pregnant blood doping!).
For the month of May, I purposefully waited until the hottest part of the day (which was around mid-eighties) to do my runs two days a week. On those days, I took it easy but made myself keep running in what felt like sweltering heat for at least ninety minutes. On those runs I was sure not only to refuel but to rehydrate and to pay attention to my micronutrient intake as well. As May's temps ratcheted up in June, I felt more comfortable running in the heat already. During the month of June I tacked on to the end of every hot run an ice bath in whatever creek or river was nearby. I also began to do a hot epsom bath after one run-ice bath combo per week.
Beginning in the end of June and early July, my body started performing really well in the heat. I still took my hardest and longest runs at higher elevations and at cooler times of the day but by that point in the summer I was running four or five days a week in temperatures exceeding 90F. After every run beginning in mid-July I did a full-body ice bath in the Chewuch River or Deer Lake.
At the end of July the Diamond Creek Fire flared up a few miles from home dumping an obscene amount of smoke into my little river valley so I began to wear a ventilator (read more on running in wildfire country). Not one to complain about challenging conditions I chose to view my ventilator as yet another cardiac challenge to my strengthening system. Through all of August I ran at least four of my runs per week in the ventilator in temperatures over 95F - and damn did some of those runs feel tough.
As the heat persisted through the first weeks of September I began to feel markedly more at ease in the triple-digits. I found myself looking forward to runs on hot days and even found myself not feeling overheated on my last hot hot run on September 14th.
Now, as the cold rolls in and the ground I now run on is covered with snow, I feel more well-adapted to running in freezing, damp temperatures, too. My body feels like it is using much less energy than in past seasons keeping me warm despite being vastly leaner this autumn versus years past. And dammit if I'm not pining for those sultry runs in the smoke with Moose.
So after four months of shirt-free, sweat-heavy, hot AF runs I'm pleased to announce: I loved it! Truly. After a lifetime of not performing well in the heat I now miss my hot 4pm runs on sun-exposed dusty trail. I'm also performing better in the cold this autumn AND feel my overall cardiac capacity increased. Now let's see how that heat training translates to high altitude movement - I'll keep you posted.