Marathon Blog

Training tips for summer weather


Many of you are probably training for the Healthy Driven Naperville Half Marathon or 5K (or another fall race) and by October, the weather will likely be much more favorable for running a successful race. Unfortunately, your training plan calls for long runs in the summer, during the heat, humidity (and possibly rain and thunderstorms) of August and September. Here are some tips to successfully make it through those late-summer long runs:

Watch the weather. First and foremost, watch the weather forecast. If you learn in advance that your long run will fall on a day with less favorable conditions, adjust your plan accordingly. Keep in mind that your running performance drops below optimal levels when temperatures are above 55 degrees and will fall off 10% or more when temperatures exceed 80. Also keep in mind that no place outdoors is safe for running during a thunderstorm.

Have a plan B. If it looks like your long run is planned for a hot, humid day or a day with forecasted thunderstorms, consider these options:

Switch the day. Consider moving your long run 1-2 days earlier (or later) if your schedule allows. Your long run is your most important run each week, so moving or adjusting a couple of your shorter runs won’t hurt your training. The goal for the week is to have a successful long run.

Start early/switch the time. Starting at 5 a.m. can make a big difference in the amount of heat and humidity you face during your long run. Getting most of your long run in before the sun rises can improve your chances for success. Similarly, switching the time of your run to avoid thunderstorms will keep you safe. The weather app on your phone can be configured to detect lightning in your area; seek shelter immediately if lightning strikes in your area during a run.

Find the shade. A shady course can make as much as a 10-degree difference in ambient temperature and will help you to avoid the heat. Remember, shade is not an option to avoid thunderstorms.

Go indoors. Consider doing your long run on a treadmill or indoor track. It might be more tedious, but the conditions will be much more favorable. This will allow you to achieve your goal training pace more successfully than running outside in 90+ degree heat or during bad storms. To avoid boredom, listen to music or a podcast, or run with a training partner.

Acclimate to the heat. You can adjust to the heat of summer, but it will take 5-10 sessions of running in the heat at a much slower pace (and possibly for a shorter distance) than you normally run. Make sure you are well hydrated before and during these runs:

  • Two hours before the run, drink between 17 and 20 ounces of water. About 10 minutes before you run, drink another 10 to 12 ounces.
  • During the run, drink approximately 7-10 oz every 10-20 minutes. Adjust this as necessary based on your own ‘sweat rate’. If your run will last longer than 60 minutes, consider replacing half of the water with an equal amount of electrolyte drink (Gatorade, Powerade, etc.). You can mix the water and Gatorade for convenience and digestibility.

If all else fails, you have no other option and you must run in the heat and humidity (and you are not acclimated to the heat), hydrate (as discussed above) and slow your pace. One of the main purposes of the long run is to teach your body to handle exertion and energy expenditure over a long period of time. In the heat, exertion levels and energy expenditure will be much higher for a given running pace.

Hydrate properly before your run and go as slowly as necessary to complete your long run, taking frequent hydration breaks (including both water and electrolytes) and walking breaks. If you have extra water (don’t use electrolyte drink), pour some on your head and neck to keep cool. Don’t worry about your pace or time; the training effect is occurring and in your next long run, weather permitting, you will do and feel much better. If you do run outside in the heat, watch for signs of heat illness (nausea, fatigue/weakness, dizziness, cramping, confusion). If any of these occur, stop immediately and cool your body (go indoors, hydrate, put cool water on your head, neck and body). If symptoms persist, seek medical attention. 

A quick note on long-run terrain: make sure your long runs are on similar terrain (surface, elevation, etc.) as your target race. This will enhance your preparation for your race. More tips on practicing for race day will be covered in an upcoming article.

Stay patient and confident through these late-summer long runs and when the weather cools, you will reap the benefits of difficult training in summer weather.

Laurie Lasseter Marathoner
ACE Certified Personal Trainer
RRCA Certified Running Coach
Edward-Elmhurst Health & Fitness