What running in the heat can feel like.

My running club met recently at the house of one of our members, instead of our usual location by one of the canal paths. A few times over the summer we do this, in order to go on a run, and then return for breakfast and a swim.

The official start time was 5:00 a.m., but a few of us started at 4:00. Yes, that means dragging ourselves out of bed in the early 3’s—insanity. And this time of year, adding insult to that injury, it was already 92 degrees, and sticky, when we started! Dry heat? When I came back to the house after my run, several of us were standing outside, hoping to dry off a bit before going inside—it wasn’t happening. We were just staying hot and sticky. Welcome to summer training.

On my recent trip to Alaska to run a marathon (oh, and to see one of my daughters), I was frequently asked if Arizonans just avoid running in the summer months. I told them “no,” because there are so many great fall marathons in the Southwest we are preparing to run (St. George, Mt. Lemmon, California International, St. Charleston, Big Cottonwood, etc.). So, we continue to run, even in June, July, and August.

Then they ask now hot it is when I train. My answer—usually between 72 and 75 degrees. In Arizona? Yes: During the hottest months, I head inside for most of my weekday runs, where my gym provides AC, water, bathrooms, and even television. Still, I do usually go outside with the club on Saturday for the longest run of the week. I have many running friends who cannot stand treadmills, and do choose to forego summer training and those fall marathons. Others brave the heat on all their runs, but usually in the morning (when it is still in the mere 90s).

Even though I do often head to the gym, for a more comfortable running experience, I have a relatively high tolerance for the heat. I even thought about taking on the Death Valley Marathon, which is known for its shoe-melting temperatures (really). But, last summer I took a 6 mile run around Tempe Town Lake, in the middle of the afternoon, with my friend Win Koerper. The air temperature was 116 (F). Because we were on asphalt, the temperature for us could have been even 10 degrees (F) higher. I honestly felt the soles of my running shoes turning tacky during the run. We survived it, but I scratched Death Valley off my list!

There are definitely drawbacks to exercising in the heat. First, it does slow you down. The sports scientists have tested this enough to know it isn’t just psychological. Essentially, for a runner, there is about a 3% drop in pace for every 10 degrees Fahrenheit. If I run a marathon in 3 hours and 30 minutes at 50 degrees, I would come in at about 3 hours and 50 minutes, if the marathon temperature were 80 degrees instead—20 minutes slower.  It is simply going to take more effort to maintain the same speed, translating into slower times. But, if you train in the heat, and then run a cool temperature marathon, you are going to gain speed at equal effort, improving the pace, sometimes considerably.  I have felt this benefit a number of times. I assume other workout routines would have an equivalent challenge/benefit outcome.

Of course, hydration is more important than ever during summer workouts. Or is it? The myths, misconceptions, and anecdotal conclusions around how much to drink during exercise, and the consequences of getting it wrong, are ubiquitous and confusing (and probably merit their own post). I have seen a good number of studies that shed doubt on many of our conceptions about hydration (overstating the emergency). Professor Timothy Noakes, of Cape Town University likely the most active challenger of hydration myths. For example, he has shown that it is a myth that your “before and after” workout weight is nearly a direct reflection of how much water you lost. A lot of that weight is actually carbohydrate loss! Yep. Science. However, you can still lose a several pounds just in water on a long summer run. My total weight swing on a long summer run is about 5 pounds—and I am not very big. So, I still try to drink a lot of water.

But why go through the trouble of training through the summer? It is true that I also enjoy the winter and spring events that do not require me to train in the summer. But, because I still plan to eat, stress, work, have a heart beat, and age, through the summer, I need a reason to exercise. In other words, the rest of my life, and my physiology, does not care that it is summer in Arizona. So, running in the 90s, in the early morning, in the dark, or on a treadmill, is just part of the plan. Those fall marathons are coming.


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