In the RockMyRun ‘Ask The Fitness Psych’ blog series, we have fitness, sports and health behavior science coach Dr. Michael Mantell answer questions from RunRockers! Have your own question? Email Dr. Mantell at


Hello! I live in Costa Rica. We do not have Summer, Winter or Fall we just have rainy season or summer season. Right now is rainy season here and it is sunny and moist during the morning and rainy (a lot) during the afternoon. I usually go out for training at 5:00 pm or 6:00 pm and temperature is perfect at that time (not hot neither too cold). I’ll have a race soon and it’ll start at 8:00 am. I bet it will be sunny and terrible humid. What can I do to prepare my self to those conditions? – RunRocker S.

Running in Costa Rica with its challenging mountains, forests and beaches, can be a terrific experience. Then again, heat, humidity and rain, can be a bothersome factor for some. Some runners handle these weather conditions better than others, of course. And the fact is, we can’t always run in 50 degree, light wind, overcast weather.

Keep this in mind. When you run in any conditions, your body temperature increases as a natural accommodation, which cause your sweat glands to produce, well, sweat. In most conditions, the sweat on your skin vaporizes and disappears. In humid weather, your sweat glands will produce sweat but the sweat won’t evaporate. This may lead to dehydration, impaired blood flow, escalating heart rate by about 12-15 beats per minute or more as the temp goes from the 70’s to the 90’s, and cognitive difficulties including dizziness and disorientation. Be aware of these indicators of humidity exhaustion, and of course take a rest, hydrate and recuperate. I suggest you don’t only drink water, but include water-rich fruits and veggies as well.

What you wear can also help. Be sure the clothing you wear is made of micro-fiber, high-tech, sweat-wicking material. Light colors will reflect heat better than dark colors. Don’t forget your neck and head, so a visor is important.

In preparing for for a humid run, don’t focus so much on your regular pacing at first, and instead learn to identify the early signs of humidity exhaustion. Given enough time for preparation, watching your hydration, you’ll have time to focus on the pacing and emerge victorious.

Good luck in your race!



Michael R. Mantell, Ph.D. has served as an Assistant Clinical Professor in the Department of Psychiatry at the University of California, San Diego and as the Senior Fitness Consultant for Behavioral Sciences for the American Council on Exercise. He is a behavioral sciences coach and consultant, an Advisor to many fitness and health organizations, a member of the Scientific Advisory Board of the International Council on Active Aging, the Chief Consultant for Behavior Sciences for the Premier Fitness Camp at Omni La Costa, a presenter for Rancho La Puerta, a best-selling author and an international fitness-health speaker. In 2013, named Dr. Mantell as one of “The 100 Most Influential People in Health and Fitness.”