Tuesday, June 7, 2016

Blood, Sweat, and Training in the Heat

Summer is officially here.  Maybe not by the calendar, but definitely by the thermometer.  In just a few days the temps here went from pleasant 60s and 70s to 80s and 90s.  Ughhh!  After my less-than-stellar performance in the Red Rock Relay – which I attribute entirely to the heat – I’m really worried about running in the valleys this summer.

For the past four summers, my running challenge has been altitude.  So I studied altitude training and implemented what I learned.  Logic would say that there are techniques for learning to run in heat as well.  I began my research on runnersworld.com, where I learned why heat impacts runners and what to do about it. 

According to the article Good Reasons to Love Training Through Summer, “Yes, [the heat] slows your pace--by 1.5 to 3 percent for every 10-degree jump above 55°F, in fact…But by training through scorching temperatures, runners reap a performance boost come autumn.  In hot weather, one way your body tries to cool itself is by sending blood to the skin's surface, where the blood's heat dissipates into the air, says Janet Hamilton, a Georgia-based running coach and exercise physiologist. This cooling action diverts blood (and its run-fueling oxygen) away from working muscles. To satisfy the opposing demands of cooling and exercising, your body makes more blood. Once the mercury drops, your muscles enjoy this surplus. "You feel like you can fly, like Peter Pan," Hamilton says. "If you're on the cusp of a PR, heat training can be the factor that closes the gap."

The article, Ten Ways for Making Hot Weather Tolerable explains the physiology further.  “When you run, you get warm because your exercising muscles increase body temperature. When body temperature rises, a greater percentage of blood flow is directed to your skin surface in order to carry away this internal heat, and you break a sweat. However, it is not sweating that cools you, but rather the evaporation of the sweat from your skin. As sweat evaporates, we are cooled.

Since sweat is composed of plasma from your blood, sweating can decrease blood volume. This is why adequate hydration becomes extremely important in hot weather. ..As blood flow is redirected to the skin's surface, it means less blood is available to your working muscles. With less blood available, the heart is forced to work harder to sustain hard running, and the result is a higher heart rate. Simply put, warm, humid weather means your usual run pace has just become much harder. ..”

And while the above-referenced article did present 10 tips for running in hot weather, I like the presentation from the article Running in the Heat better:

“1. Make adjustments: Don’t do long or higher-intensity workouts during the heat of the day… As a general rule, start your workout slower than you usually do. If you’re feeling good halfway through, it’s okay to speed up a little bit.
2. Wear as little as possible: Wear apparel that’s light in color, lightweight, and has vents or mesh. Microfiber polyesters and cotton blends are good fabric choices. Also, be sure to wear a hat, shades, and sunscreen with an SPF of 30 or higher. 

3. Watch your alcohol and meds: Alcohol, antihistamines, and antidepressants can all have a dehydrating effect. Using them just before a run can make you have to pee, compounding your risk of dehydration.
4. Drink early and often: Top off your fluid stores with 16 ounces of sports drink an hour before you head out. Then toss down five to eight ounces of sports drink about every 20 minutes while working out. Sports drinks beat water because they contain electrolytes, which increase your water-absorption rate, replace the electrolytes you lose in sweat, and taste good, making it easy to drink more.
5. Be patient: Give yourself eight to 14 days to acclimatize to hot weather, gradually increasing the length and intensity of your training. In that time, your body will learn to decrease your heart rate, decrease your core body temperature, and increase your sweat rate.
6. Seek grass and shade: It’s always hotter in cities than in surrounding areas because asphalt and concrete retain heat. 

7. Check the breeze: If possible, start your run going with the wind and then run back with a headwind. Running into the wind has a cooling effect, and you’ll need that in the second half of a run.
8. Head out early or late: Even in the worst heat wave, it cools off significantly by dawn. Get your run done then, and you’ll feel good about it all day. Can’t fit it in? Wait until evening, when the sun’s rays aren’t as strong—just don’t do it so late that it keeps you from getting to sleep.
9. Slow down: Every 5°F rise in temperature above 60°F can slow your pace by as much as 20 to 30 seconds per mile. So don’t fight it—just slow down.

10. Run in water: Substitute one weekly outdoor walk or run with a pool-running session of the same duration. If you’re new to pool running, use a flotation device and simply move your legs as if you were running on land, with a slightly exaggerated forward lean and vigorous arm pump.”

So now I know.  And as much as I would like to avoid the heat, I can at least embrace it as a great way to train.  I wonder if heat training will help at altitude.  I guess I’ll find out – the Yellowstone Half is just days away!

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