SHAREABLE RESOURCE: Exercise Safely This Summer : ACSM's Health & Fitness Journal

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Departments: Fitness Focus


Exercise Safely This Summer

DeSimone, Grace T. B.A.

ACSM's Health & Fitness Journal 21(4):p 3, July/August 2017. | DOI: 10.1249/FIT.0000000000000306
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Summer is a wonderful time to take advantage of the great outdoors and exercise outside more often. Keep in mind though, outdoor workouts are not for everyone. The U.S. Centers for Disease Control and Prevention reminds us that you can become ill from the heat if your body can’t compensate for it and properly cool you off. This could result in a heat-related illness that can be quite serious. Anyone is at risk — even a highly trained athlete. Thus, it is important to learn and recognize the signs and symptoms for yourself or a companion. Failure to respond to a person in distress can result in severe dehydration and, in extreme conditions, death.


  • Heat cramps: painful involuntary muscle contractions caused by altered nervous control of the muscles that is exacerbated by fatigue, dehydration, and electrolyte imbalance.
  • Heat exhaustion: inability to continue to exercise because of heat-induced symptoms such as nausea, headache, hyperventilation, etc. Generally occurs at a body core temperature of 97° to 104°F. Can quickly progress to heat stroke.
  • Heat stroke: a body core temperature that reaches 40°C (104°F) or more. This condition is life threatening unless promptly recognized and treated. Confusion; hot, red skin; disorientation; profuse sweating; hyperventilation; loss of balance; rapid pulse; and possible loss of consciousness are all signs to look for in a person experiencing heat stroke.

Another factor that compounds an individual’s heat tolerance is high environmental humidity, where sweat won’t evaporate as quickly, if at all. This keeps your body from releasing heat as fast as it may need to and results in overheating.

Personal factors also are major influences in heat tolerance. Age, obesity, fever, dehydration, heart disease, mental illness, poor circulation, sunburn, prescription drugs, and alcohol use can play a role in whether a person can cool off enough in very hot weather.

Make sure you play it safe with these warm weather exercise tips:

Stay Away from Midday: Unless you are training for an event that takes place in the midday heat, avoid exercising from 10 a.m. to 3 p.m. Generally, the early morning or sundown is the best time to work out. If you can, choose shaded trails or pathways that keep you out of the sun.

Light and Loose: Wear loose lightweight and light-colored clothing. Light-colored clothing reflects the sun to keep you cooler, whereas dark colors absorb the heat and make you feel warmer. Stick to fabrics that wick moisture away from your body. Many apparel companies offer fabrics with SPF 50+ that is an added bonus.

Good Nutritional Intake is Critical: Proper food intake, especially real food, promotes fluid intake and retention. Normal fluid intake with meals supports prehydration before activities and helps prevent/delay dehydration.

Remember to Drink: Exercise in hot/humid weather will require more fluid intake than usual. Because people of different sizes, sex, and physical condition sweat at different rates, checking your weight pre-post training will help to zero in on your personal fluid requirements. At a minimum, make sure you start each training session and competition hydrated and drink during the activity as well.

Pace Yourself: Start out slowly and gradually pick up your intensity while monitoring your response. Remember that your body is working to acclimate to the hotter environment in addition to the workout, so don’t expect your body to perform as well as it does in a cooler, less humid condition.

Apply and Reapply: Wear sunscreen and reapply as directed.

Weather or Not: Check the weather forecast before you start your workout. If there’s a heat or other advisory, such as high ozone and air pollution, consider taking your workout indoors. In addition to the heat challenges, environmental pollutants can trigger asthma, allergic responses, and even lung damage over time.

Body Knows best, so listen to it: The great benefit to having a routine is that your body knows what to expect. You will be able to recognize when your body isn’t performing as it normally does and be able to adjust accordingly. If you feel dizzy, disoriented, or light-headed, discontinue exercise, let somebody know, move to a shady location, and hydrate until you feel better.

As the national group fitness director for Optum, Grace T. DeSimone, B.A., and her group fitness teams manage group exercise classes in worksite wellness programs across the country. She serves on the Executive Council of ACSM’s Committee on Certification and Registry Boards. She also is the editor for ACSM’s Resource Manual for Group Exercise Instructors (2011) and is the 2016 IDEA Health & Fitness Association Program Director of the Year. She holds a bachelor of arts degree in dance from Hunter College, City University of New York, in New York, NY and is certified by ACSM as a group exercise instructor and personal trainer.

© 2017 American College of Sports Medicine.