Entering my house coated with a glowing sheen of sweat is my favorite piece of evidence of a satisfying run. No matter the season, sweat is inevitable. But sometimes, I am compelled to clamp down my running shoes in the middle of the day, the noon sun a laserbeam directly pointed at me. I have learned the hard way that Orange County running requires a baseball cap at peak hours, and I often have considered getting eye-concious and sporting sunglasses while I jog, despite the fact my sweat gives them a free ride down my nose, so I am constantly trying to adjust them.
Sweat aside, there are more serious risks posed to summertime runners. Skin damage, and health damage can occur in the heat or prolonged time spent working out in the sun. In “Turning Up the Heat,” Amby Burfoot reports:
During the hot run, my heart rate soared to 175, about 96 percent of my max. My temperature spiked to 103.5, close to the edge of heatstroke, which can potentially occur when your core temperature reaches 104.0. My lactic acid climbed above 4.0, the point most physiologists define as the lactate threshold where the leg muscles no longer function efficiently. And my plasma volume contracted by more than 10 percent, which, coupled with a 2.6 percent total dehydration, forced my heart to work harder to push blood to my legs. All this at a pace I considered comfortable. If I had run much longer or harder at 90 degrees, it’s possible that I could have staggered into heat illness, the precursor to the heatstroke hurt zone.
Ninety degree weather is dangerous for a runner, and can cause serious illness. The severity and extreme change in body temperature alarms me, given my penchant for always assuming I’ll be fine, no matter what the temperature is.*
You don’t have to be Sherlock Holmes in order to be a summertime runner, though. Wear sunscreen. Drink more water. Run early in the morning or later in the evening. And if it’s over 95 degrees, trying walking instead. Does all this put a damper on my workout plan? Sure. But I try to remember that it’s better to give it a day or two than not be able to run at all because I’m busy being cooped up in the hospital, or dead.