run, janelle, run!

Tips for running in humid weather

I had had a rough night.

Battling snakes in your dreams for 6 hours doesn’t lend itself to being “well rested”. Throw on top of that a day consumed by staring at a computer screen, and the last thing I wanted to do was go for a run.

However, I knew it would make me feel better. But before I embark on that, let me say a couple of things about what it’s like to go running around here with summer looming right around the corner.

Weather woes in NC

If you’ve never experienced the weather in Raleigh, NC at this time of year, imagine living in the middle of a tropical jungle. The air is moist and oppressive; horseflies and other creepy crawly bugs are abundant; the sun beats angrily down on you; and every time it rains, you can almost always expect some sort of severe weather warning to go along with it.

In the mornings, I’ve found that the humidity tends to be slightly worse (depending on whether or not it has rained recently); so, my decision to round out my day with an evening run only made sense. As it turned out- those snakes didn’t have nothin’ on me. I clocked in my 10.75 mile run at just under  1 hour and 12 minutes…not too shabby given the fact that I had been battling sleeplessness, eating a little too close to my run, and an 80% humidity level. Now, imagine what I really could’ve done if I was firing on all engines!

[photo by Dave Goodman on flickr]

Humidity is no laughing matter

All of the kidding aside, running at any pace when it is super humid outside is no joke. Below are some quick facts and info to help you make the most of your runs when the weather is humid.

5 Fast facts about humidity for athletes:

  • Your heart rate (HR) is likely to increase up to 10 beats per minute in humidity levels ranging from 50-90%.
  • In temperatures ranging from 60°F to 75°F, your HR is likely to increase by up to 2-4 beats per minute.
  • In temperatures ranging from 75°F to 90°F, your HR is likely to increase up to 10 beats per minute [source].
  • If you have a pre-existing medical condition (diabetes, asthma, heart disease, etc.), you are at a much greater risk for heat stroke.
  • When it is extremely humid outside, your body works doubly hard to cool itself. If you’re not careful, your body can overheat, causing hyperthermia.
To find the Heat Index temperature, look at the Heat Index chart below. As an example, if the air temperature is 96°F and the relative humidity is 65%, the heat index–how hot it feels–is 121°F. The Weather Service will initiate alert procedures when the Heat Index is expected to exceed 105°-110°F (depending on local climate) for at least 2 consecutive days [source].

10 Tidbits for tackling your next humidity-filled run:

  1. Start slow. It takes time for your body to become acclimated to the warmer, more humid weather. Start off by running in humid weather slowly; then build your way up to a pace that is comfortable for you.
  2. Invest in moisture-wicking athletic attire.  A sales professional can help you with this at any number of sports stores…or you can Google it. Go for light-weight, loose-fitting clothing that aims to evaporate moisture while you exercise. Avoid wearing dark colors (which will trap heat) or clothing made of cotton as it will trap moisture.
  3. Exercise early in the morning or later in the evening. Only a crazy person would attempt to do a hardcore run during the middle of the day when the sun is beating down. If you can’t squeeze a run in in the morning or late at night, head indoors and hit the treadmill. You’ll be better off. If you absolutely must exercise outdoors, hit the trails and stick to the shaded areas.
  4. Stay hydrated. Fluids replacement is never more important or vital than when you are battling humidity. Drinking water is always a must; and you should aim to consume around20 ounces of water a couple of hours before you head out. Follow this up with an additional 10 ounces of fluid for every 15 minutes of exercise- perhaps more if you’re amping up the intensity. Also keep keep an energy drink handy for after you’ve finished running in order to help replace any electrolytes that were lost. Can’t handle energy drinks post-run? I usually bring a piece of fruit with me or a small energy bar, which I wash down with water.
  5. Pay attention to weather forecasts. Pay close attention to the heat index, which is the measure of how hot it really feels once you factor in the relative humidity with the actual temperature outside. Use the chart above to determine whether you want to risk running in current conditions.
  6. Weigh yourself to determine hydration needs. I cannot stress enough how important it is to stay hydrated-especially during the summer months. Before you run, strip down to your birthday suit and weigh in. Go for your run. After you finish running, apply the following formula in order to determine your fluid needs: [post-run weight – pre-run weight + fluid consumed = total fluid loss] THEN– [Divide the ‘total fluid loss’ by the number of miles you ran to get your total fluid consumption needed/mile] [source].
  7. Run short. You don’t have to marathon it up out there in order to pack in a decent workout. Keep your runs shorter and increase the intensity slightly depending on how you feel. Trying to do a long run that day? Split it up to keep things safe and efficient.
  8. Sip cool water after running. Cool down…literally….by sipping on cold water after you’ve finished running. It will help your body cool down. There are also some who suggest drinking cold water prior to running as it will take your body longer to heat up.
  9. Take breaks. There is no shame in slowing things down to a brisk walk or even stopping to catch your breath. This is much better than the alternative.
  10. Invest in the right sunscreen. While waterproof sunscreen may seem like the obvious choice for someone who’s about to embark on a long, sweaty run, there is some speculation that (particularly in humid weather) some brands of sunscreen may actually inhibit the sweating process, causing residue to build up on your skin and prevent the body from being able to properly cool itself down. Therefore, make sure you really read those labels; or failing that, voice your concerns with your doctor.


Weather forecast for tonight: dark. -George Carlin



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