Warmer weather also means that our bodies will start to respond differently from what we are accustomed.
How does heat affect a workout?
Runners World did an in depth study on how heat affects runners.
A quick recap of the article: The author ran two identical workouts on consecutive days – one hour at 8:30 per mile pace. The first run was in 53 degree conditions, the second at 90 degrees. The results were staggering.
Body Measurements at 53°F
Heart rate 158
Rectal temperature 101.98
Sweat loss 27.05 ounces
Percent dehydrated 1.3
Body Measurements at 90°F
Heart rate 175
Rectal temperature 103.45
Sweat loss 54.10 ounces
Percent dehydrated 2.6
Notice the dramatic increase in heart rate and the fact that the sweat loss and percentage dehydrated DOUBLED.
Also, his temperature of 103.46 is dangerously close to heat stroke (which occurs at 104).
What does this mean?
- Our bodies have to work much harder in the heat to cool our bodies.
- For sweating and cooling to occur, the body must increase blood flow to the surface of the skin. So, when we sweat at high rates, we’re actually losing blood volume, not to mention electrolytes.
- According to running.competitor.com, “Increased skin blood flow is problematic for an endurance athlete because less blood is available to working muscles and vital organs such as the heart, making exercise more difficult.”
But, wait! There are benefits of the added stress that heat puts on our bodies.
Men’s Fitness reported that “Researchers discovered that the cyclists who worked through the heat improved their performance by 7 percent (a very noticeable and significant amount), while the control group did not show any improvement. What surprised researchers most was that the experimental group not only showed that they had achieved a level of heat acclimation, but the training also helped them to function better in cooler environments.”
Bottom Line regarding working out in the heat.
“People just need to be wise enough to listen to their bodies,” says Cedric Bryant, Ph.D., a fitness expert for the American Council on Exercise. “It isn’t a ‘no pain, no gain’ situation.”
Dr. Bryant recommends consuming 16 to 24 ounces of water a couple hours before exercising in hot temperatures. Past that, he says to take in another six to eight ounces of fluids every 15 to 20 minutes of exercise.