For most of my adult life I carefully limited my sun exposure. More recently—after discovering that the more sun exposure I got the better I felt—I’ve been trying to get as much as I could without getting burned. Just lately I’ve been groping towards something more nuanced.
Back in maybe the 1980s I briefly tried to follow the advice of dermatologists to never go out without sunblock. That didn’t work well—inevitably there would come the day when I was unexpected out in the sun longer than expected, and (not having built up a protective tan) I’d end up burned.
After that, for a decade or two, I came up with some simple rules: Unlimited sun before 8:00 AM and after 5:00 PM, but I’d aim to get 20 minutes of mid-day sun. If I was going to get more than that, I’d wear sunblock, but I tried to get that much sun every sunny day. That worked pretty well—I’d get enough of a tan to provide some protection on those days that I was unexpectedly out in the sun.
That schedule, of course, fell out pretty much automatically from working at a regular job. I stuck with it even after I wasn’t working at a regular job because it worked pretty well.
For various reasons, such as needing to take very long walks to train for our big Kal-Haven trail walk, I started spending more time out in the sun, and began to observe that the more time I spent in the sun the better I felt, leading me to get what was probably more sun than is really wise.
Since recently running into the idea that certain frequencies of red and near-infrared light are good for your skin and deeper tissues, I’ve been prompted to think about all this in a more systematic way, and have been trying to come up with a plan that maximizes the benefits while reducing the harm caused by sun exposure.
I’m still in the research stage, but here are the early changes that I’m making:
First, I’m reducing the amount of mid-day sun I’m getting. I’ve been going for around 40 minutes (as much as I can get without risk of burning), but I’m bringing that back to around 20 minutes. Still enough time to make plenty of vitamin D.
Second, I’m replacing that 20 minutes of mid-day sun with 20 (or more) minutes of sunlight during the period that the UV index is between 1 and 3. (This time of year, where I live, that’s maybe 7:30 AM until 9:00 AM.) My hope is that part of the reason more sun makes me feel better is the red light (rather than the UV), and that morning and evening sun can provide those frequencies.
Third, I’m trying to get some very early (dawn) sun exposure. This is specifically for the effect early morning light has on the circadian rhythm.
Only in the middle of writing this did I realize the extent to which I’ve come back to what I did for most of my working years—except that instead of having to squeeze my morning sun exposure into the time I spent crossing the parking lot, now I can extend it to 20 minutes or longer, and combine it with a proper walk in nature for some sweet, sweet vitamin N.
I went for a long-for-me, 7.22-mile run this morning, and listened to a podcast about light therapy.
(I go back and forth on listening to podcasts during runs. When I listen I feel like I miss out on being fully embodied in my physical activity. When I don’t listen I fall behind on stuff I really want to listen to. Today I listened.)
The podcast had Paleo Magazine‘s Ashleigh Van Houten interviewing Scott Nelson, the founder of Joovv, talking about the health benefits of exposing your skin to red and near-infrared light. I’d heard about this, but had assumed it was some woo-woo new-agey thing. Turns out it’s probably not. There’s been a huge amount of research on the benefits of exposing your skin to red light in the 660-nanometer and near-infrared light in 850-nanometer range.
(There was apparently a lot of research funded by NASA back in the 1990s when they had to use lasers to get light of just the right frequency. Nowadays LEDs make it easy to get the intensity and frequency of light that you want.)
So, I’m out on my run, listening to Ashleigh and Scott talk about all the health benefits to your skin (of the red light) and to deeper connective tissues (of the near-infrared) and thinking that it all sounds really cool, but knowing that I’m probably never going to want to spend even hundreds, let alone thousands, of dollars to buy a device that will shine bright red light on my skin.
At around the mid-point, maybe 4 miles into my run, I paused for a drink of water out of the fountain in Morrissey Park, thinking it was pretty hot for just 8:40 AM . Which made me think of this giant glowing orb in the sky, which was shining down on me with pretty intense light at a wide range of frequencies, most definitely including red and near-infrared.
Turns out, sure enough—the energy in the red and near-infrared frequencies of sunlight is right in the range of therapeutic doses shown to have health benefits.
Of course, full sunlight is full of other frequencies of light, including blue (prone to mess up your circadian rhythm if you’re exposed too close to bedtime, but just what you want to get your circadian rhythm set correctly if you get your exposure in the early morning like I was doing), and ultraviolet (dangerous in excess, but the UV index was zero when I started my run at 7:40 AM and probably didn’t reach 5 before I was safely back indoors). So you need to treat sunlight with respect. But I already knew that.
I have mentioned before that I feel better when I spend a lot of time outdoors, and have speculated that sun exposure is part of the reason. (Along with time in nature, moving more, appropriate quantities of community and solitude, etc.) The information about red and near-infrared light exposure seems to lean a bit in the sunlight direction—but with the welcome news that it’s not just the vitamin D that helps make me feel better, which means maybe I can feel great without having to expose myself so much to the deadly actinic rays of the sun.
Of the many good things about spring, about now is when the lightening sky starts providing useful cues for waking up. If it’s still dark, I don’t need to check the time and can just go back to sleep. And if it’s getting light outside, it’s time to get up.
I shared a link to this article by Rowan Jacobsen, with the comment “This article falls so squarely in the sweet spot of reinforcing my own preconceptions, I almost hesitate to tweet it.” But I did, with a few brief quotes.
Freed of the limitations of twitter, here’s a more extended excerpt:
Lindqvist tracked the sunbathing habits of nearly 30,000 women in Sweden over 20 years. Originally, he was studying blood clots, which he found occurred less frequently in women who spent more time in the sun—and less frequently during the summer. Lindqvist looked at diabetes next. Sure enough, the sun worshippers had much lower rates. Melanoma? True, the sun worshippers had a higher incidence of it—but they were eight times less likely to die from it.
So Lindqvist decided to look at overall mortality rates, and the results were shocking. Over the 20 years of the study, sun avoiders were twice as likely to die as sun worshippers.
There are not many daily lifestyle choices that double your risk of dying. In a 2016 study published in the Journal of Internal Medicine, Lindqvist’s team put it in perspective: “Avoidance of sun exposure is a risk factor of a similar magnitude as smoking, in terms of life expectancy.”
Jacobsen later mentions the app dminder, which I’ve been using for several years now. It helps you optimize your sun exposure (getting maximum vitamin D production without getting sunburned, based on time of year, time of day, location, and skin pigmentation). I just checked the app, which tells me that it’s just 8 days until the vitamin D window reopens here in Savoy, Illinois!
I concluded my little tweet storm with this: Pretty much every nice day of the spring, summer, and fall, I announce to my wife around midday that “I’m going out to expose my integument to the deadly actinic rays of the sun.” And then I do. I feel so much better since I started doing this.
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.