When is it too hot to run outside?

Q:  I'm looking for best practices / tips for training in the heat/humidity. And at what point is it too hot to run outside?

A:  Running in the summer can be a double-edged sword.  On one hand, there's no snow or ice to deal with (and less layers to dress in!).  On the other, it can be downright discouraging and frustrating, especially if you are training for a Fall race.

Here are some tips to survive the dog days of summer:

Run by effort, not pace.

Running in the heat causes your body temperature to increase and your performance begins to decline.  More blood is diverted to the skin (evaporation of sweat for cooling), meaning there is less blood available to carry oxygen to your muscles.  Less oxygen to your working muscles translates to slower paces.

If your workout on a hot and humid day calls for X miles at X pace, it's best to adjust your expectations and run by perceived effort instead.  You will still reap the benefits without compromising any other workouts you may have planned that week.

Know the dew point.

The dew point is the best way to gauge how tough a run will feel.  The closer the dew point is to the air temperature, the more oppressive it will feel (check out this handy guide for how to adjust your runs at various dew points).  Try to head out early in the morning or later in the evening when you're less likely to battle both the sun and the humidity.

Hydrate, hydrate, hydrate.

Dehydration also adversely affects performance.  Ensure that you are drinking enough water throughout the day and during your run.  Carry a water bottle or run in a location with water fountains.  Don't forget electrolytes too!  Maybe add a pinch of salt to your water, more salt to your diet, or an electrolyte tablet to your water.  A sports drink like Gatorade will also suffice.

Know when to call it quits.

Everyone responds differently to running in the heat, which makes it difficult to pinpoint when you are better off rescheduling a run to a (slightly) cooler day.  Take note of how you are feeling during the run.  If you start to feel light-headed or nauseous, it's time to call it quits.  Recognize the signs of heat-related illness and be smart about your training.

Lastly, don't be discouraged.  You are making progress and paving the way for a great Fall racing season.  Cooler temperatures are around the corner and so is the time to showcase all of your hard summer training!

Kristy Campbell is a RRCA-certified coach located in Conshohocken and founder of Run The Long Road Coaching She believes that success in running comes down to hard work, consistency, and determination.  In her spare time, she runs around after her daughter, Fiona.

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