Exercising in the heat

I have always enjoyed exercising in the heat. In this I seem to be different from most people.

I originally took note of this fondness back in the early 1980s when I was living in Ft. Lauderdale. A ritzy local tennis club—way too expensive for me—offered summer memberships for just $100. I just got access to the outdoor courts and not to the indoor amenities, but all I wanted was a place where I could reserve a court and know that it would be available when I met someone there. The only downside was that you were playing tennis outdoors, in the summer, in Ft. Lauderdale. And it turned out I was okay with that.

I’m pretty careful not to be stupid about it. (And successfully so, it seems—I’ve never gotten heat exhaustion or heat stroke.) If I start feeling tired, thirsty, or overheated, I slow down, move to the shade, and drink some cold water.

Over the years I’ve had a variety of theories about why I didn’t mind exercising in the heat when other people hate it so much. I like to imagine that I’m just better at tolerating the heat than the average person: Everyone slows down in the heat, but maybe I slow down slightly less; at some high temperature, maybe I’d become competitive! More likely, since I’m not competitive I’m not making unfavorable comparisons between my speed in the heat versus my speed in cool weather, so the fact that I slow down doesn’t make me unhappy.

Recent research has given me a new, much more likely reason why I like exercising in the heat. On Rhonda Patrick’s Found My Fitness podcast, I heard an interview with Dr. Charles Raison, in which he described the results of a study suggesting that Whole-Body Hyperthermia was an effective treatment for depression. The experiment used infrared lights to heat people up to a core body temperature of 38.5℃ (101.3℉), but Raison is convinced that there is nothing special about the device used, and that a sauna, hot spring, sweat lodge, hot yoga—or just exercising in the heat—would have the same antidepressant effect.

Dr. Raison is studying further to try to elucidate the mechanism by which hyperthermia boosts mood in depressed people. (It seems to reduce inflammation, perhaps by boosting IL-6 which activates IL-10.  Heat Shock Proteins might also be involved, since they do all sorts of things.)

I have always been inclined to blame a lack of daylight for the seasonal depression that I’m prone to suffer from during the winter—both too short of a photo-period (which I address with a HappyLight™) and too little vitamin D (which I address with vitamin D supplements), but it now occurs to me that a lack of opportunity to exercise in the heat (and thereby raise my core body temperature high enough to trigger whatever it is that reduces depression) may be an independent factor.

It seems very likely that, just like my desire to spend time outdoors in daylight is probably self-medicating to boost my vitamin D and regulate my circadian rhythm, my desire to exercise in the heat is probably self-medicating to boost my mood.

I hesitate to rejoin a fitness center just to get access to a sauna, but I’ll have to investigate options for access to winter whole-body hyperthermia.

Past mid-winter

Some time in October every year I quit being able to get enough sun to make my own vitamin D. Eventually it gets too chilly to go out with enough skin exposed, and even if it stays warm late into the fall, eventually the implacable reality of the earth’s axial tilt means there simply aren’t enough minutes of the day when the appropriate frequencies of UV light shine down where I live.

As a practical matter, this period runs about six months. By early March there’s probably enough UV available, but it’s usually early April before the stars align such that we can take full advantage. We need days when it gets warm fairly early, because the UV is only available for a few hours right around solar noon. (Warmth at 3:00 PM is great, but doesn’t help with the UV until later in the year when the sun is even higher.) We need to get at least two or three of those days each week. (Just two days would probably be enough, if one never had schedule conflicts that kept one out of the sun around solar noon.)

My experience has been this all works out to mean that I need to rely on supplements for my vitamin D needs for right around 180 days per year. With that in mind, I’ve taken to buying two 90-pill bottles of vitamin D each fall.

When I notice—as I say, usually sometime in October—that it has been several days since I managed to get enough sun, I start taking the pills.

Just a few days ago, I finished my first bottle and opened my second.

That means I’ve made it halfway through! Another 85 or 87 days and I’ll be done with the pills and able to make my own vitamin D!

The last few years I was taking 1000 IU pills. This year I upped it to 2000 IU each day. (Not quite as big a change it sounds—I used to eat a lot of children’s breakfast cereals, often supplemented with vitamin D, but since I went low-carb I’m eating a lot less of those.)

It’s still a somewhat higher dose, which I think may be helping. So far this year I’ve only had a couple of days when I found myself glum for no good reason, a bit better than average, I think.

Steven always warns me against imagining that spring starts before April. But soon—less than 90 days now—I’ll once again be able to make my own vitamin D.

Adjusting my morning routine, maybe

The natural movement people I follow continue to broaden my perspective on what constitutes natural movement. Fairly recently, in her podcast, Katy Bowman pointed out that dilating and contracting the pupil of your eye is a natural movement.

Most people spend most of their time at just a few lighting levels—dark (however dark they keep the room they sleep in, which often isn’t very dark), medium (ordinary indoor light levels), and bright (ordinary outdoor light levels). Katy suggests that there may be some benefit in experiencing the whole range of light levels, from in-the-woods-at-night dark to full-sun-at-midday light—and most especially everywhere in between.

It’s an idea that appeals to me, and I’m inclined to copy her and go outdoors while it’s still dark, and take a walk during the time from just before dawn until just after sunrise.

Taking such an early morning walk would be a change to my daily routine, and whenever I think about adjusting my daily routine I like to compare it to that of Charles Darwin. He was so productive for such a long time, I figure his is a touchstone for a successful daily routine. So I went and checked and was very pleased to see that Darwin’s daily routine included a pre-breakfast walk of about 45 minutes.

I’d previously copied some elements from Darwin’s routine, but I hadn’t taken that one. I’ve been spending that time at the computer checking email, Facebook, and my RSS feeds, and chatting on-line with my brother. Those are all things that are probably worth doing, but maybe they don’t need to be the very first things I do in the morning.

I’ve been thinking about doing this for a while, but spring has been cold and damp and not really conducive to early morning walks.

This morning I took a test walk, strolling around Winfield Village and in the Lake Park Prairie Restoration in the half hour before sunrise. It was very pleasant.

sunrise from prairie

Rejoice: The sun returns!

The solstice snuck up on me this year. The calendar shows it as being today, which it is if you live east of the United States. But it was actually a few minutes before midnight on the east coast and more than an hour before midnight here.

Happily, Geoff Landis (one of my Clarion instructors) posted a “happy solstice” message on Facebook (with a link to an astronomy site with the details) a few hours before the event, so I was able to appreciate it prospectively.

The longest night of the year has come and gone. I’m glad that’s over.

Why, in just six weeks, it’ll be Groundhog’s Day! And once that happens, it’ll be time start looking for our early spring!