Summer Running; Humidity versus Heat

Good morning.

This past week was full of emotion and sadness across the country. This forum is not the place for a discussion on race, violence, or even political views. Coffee & Chat and even NFLF has been and always will be about all people with no regard to race, color, or sexual orientation. I strongly believe what we do well, is we care about our clients without any regard to our unique differences. It is as simple as: love one another. While we cannot change the world, we feel strongly about helping the world. I personally pray for all those whose emotions are running high right now and I hope as a country, we can step back and spread love over hate. Whether I agree with everything or not, is not as important as showing grace and respect.

June is now in full gear and with that comes morning humidity and higher daily temperatures. Which one do you least like dealing with?

Knowing my Thursday was going to be busy, I decided to get out and run 40 minutes at 6:30 am. Being the experienced runner, I did my homework Wednesday night and checked the weather forecast for that specific time. No real shock, while the temperature was going to be a reasonable 65 degrees, the humidity was going to be at 85 percent. Because of my schedule I could not wait for the pending sun to burn off the moisture, so despite my dislike for humidity, I had to stay with my plan.

Humidity versus High Temperature

Laymen Science

As we stress our system it heats up and creates sweat which is essentially is water and nutrients. When the fluids (sweat) move to the bodies surface, it is then cleared out by the water dissipating (convection). Hence the importance of good hydration before, during and after exercise.

External Factors

Humidity is basically moisture (water) that lingers in the air. It tends to be higher after bouts of rain, whenever the cloud cover is low blocking the sun and in the early morning because of the hours of no sun (think morning dew).

Our physiological system, moves fluids throughout the body allowing it to function, with eventually those fluids moving to the bodies surface and dissipate through convection. If externally there is a high amount of moisture (humidity) lingering in the air, the convection process is diminished. Instead of sweat dissipating, our bodies retain it. So, while it may be only 60 degrees out, if the humidity level is high, our bodies will accumulate more sweat. The bodies entire cooling system is now working much less efficient.

On a day when the sun is out, moisture in the air typically is burned off, so while the temperature goes up, the humidity level goes down. Lower moisture in the air allows for the convection process to work more efficiently and our cooling system flows better. The problem now becomes heat and how much it tasks the body to replenish the nutrients and hydration we lose through the sweating process. High external heat requires our system to work extremely hard to maintain our performance and more important, function safely. Ridding ourselves of fluids through convection is helpful, but excessive heat will quickly deplete water and nutrients (sodium and potassium).

Which condition is best to run or workout in?

Later afternoon or early evening temperatures tend to go down and humidity tends to be lower, so I will often schedule my run around that time. If that is not possible and I have to choose between early morning (humidity) or the afternoon (heat), I prefer heat over humidity. I am a sweater, so humidity really impacts me. Many people sweat much less than me, so morning humidity may be more bearable than high temperatures. There is no better than the other, only an understanding of the challenges of each condition. Either way, hydration is critical before, during and after.

Final thoughts…

Thursday, I planned on going out for 40 minutes of running. Ultimately, I ran for 35 minutes because of the affects of the humidity on my body. We coach our runners to run for time versus a distance for various reasons. The primary reason is for healthy running. Instead of trying to force myself to run a certain distance on a challenging day, I slowed down and accepted what my body dictated and that was 35 minutes. It was an extremely grueling 35 minutes, but I was happy to have done it.

Summer running and working out is challenging, and we need to be smart. Hydration, sunscreen, and understanding our environment will all help to keep us active and safe. Every day will not be our best, but if we are willing to adjust, we can enjoy a great summer of continued running or working out.


We are beginning a beginner half marathon training group on June 20th. We will offer 2 sessions a week in person or you can train online. This training will be for all levels and will most definitely take in account the challenges of summer running!

Have a great week and spread the love!

God Bless!