Benefits, Risks, and Strategies to Stay Safe
Exercising outdoors is one of the top 20 fitness trends for 2014, according to the American College of Sports Medicine.
Extreme outdoor competitions such as the Tough Mudder, outdoor boot camp classes, walking and running groups, and even outdoor yoga and meditation classes are increasing in popularity and accessibility.
Clients at any fitness level—from the couch potato to the competitive athlete—can enjoy the outdoors while working out.
Really, the outdoor exercise trend spans all seasons. But nice summer weather motivates even more people to participate in outdoor activities.
However, exercising in the summer heat will require clients to pay special attention to hydration and consider other risks. In this article, I’ll summarize the benefits of moving workouts outdoors and then discuss modifications for exercising in the heat.
Physical and Psychological Benefits
In my May 2012 column “Hit the Trail,” I discussed the physical benefits of moving from the treadmill to the trail. These included increased intensity, workout duration, and motivation.
Whether walking, running, cycling, or doing an outdoor fitness class, the natural beauty of the outdoors provides a much better setting than a crowded gym, DVD workout, or TV program while on exercise equipment. In fact, nature itself
can be a motivator for many clients who seek the calm and serenity of natural surroundings or a breath of fresh air after spending all day cooped up in an office.
Natural terrain boosts workout intensity with hills, rocks, sand, and water. The unpredictability of natural obstacles, such as a rocky trail with puddles, requires more focus and more effort during a workout. For those exercising outdoors in urban
environments, hills and distance serve as motivators as well.
Being able to see the top of a hill or the corner of your street inspires more speed and endurance than a treadmill display screen. All of this adds up to more calories burned outside.
In articles and interviews too numerous to cite, personal trainers and exercise physiologists have noted that outdoor exercise burns anywhere from 5% to 20% more calories than similar indoor workouts.1 (Number of calories burned depends on the
type and duration of activity as well as weather conditions and terrain.) In addition, sun exposure increases the production of vitamin D, which has been shown to be lacking in many Americans.
Many medical conditions have been attributed to low levels of vitamin D, including thyroid disease, heart disease, asthma, and bone problems such as bone pain and low bone-mineral density.
In addition to physical fitness benefits, studies have shown that exercising outdoors provides mental health benefits. A 2011 systematic review of comparative data from more than 800 adults walking or running indoors vs. outdoors found that exercising outdoors in a natural setting was associated with decreased stress, confusion, anger, and depression;
increased energy; and greater feelings of revitalization and positive engagement.1 In another study of more than 1,800 adults participating in an annual general health survey, researchers suggested that there may be a “synergy between the psychological benefits of physical activity and the restorative effects of contact with a natural environment.”2 Survey results showed a 50% lower risk of poor mental health with
regular outdoor exercise in woodlands and parks.
The same sun that provides healthful vitamin D also contributes to many of the risks of outdoor exercise. Long workouts in the sun can lead to sunburn. When combined with humidity, the heat of the summer sun can cause heat cramps, heat stress, heat syncope, heat exhaustion, and heatstroke. Humid days also increase the risk of breathing problems during exercise.
A retrospective analysis of trends in exertional heat-related incidents in US emergency departments found a significant increase (greater than 130%) in exercise- and heat-related medical incidents from 1997 to 2006. Sports and exercising represented the majority of injuries (75.5%), followed by yard work (11%). Adolescents and children sustained a larger proportion of sports and recreational exertional heat-related incidents, while adults sustained more exertional heat-related incidents from yard work.
Many of these heat-related health problems can be prevented with gradual acclimatization to exercising in hotter temperatures and attention to proper hydration as well as awareness that yard chores are, in fact, exercise.4 Clients also should keep in mind that exercise-related heat problems don’t occur only with extreme temperatures.
Another summer risk is wildlife. Often overlooked, insects and animals can make outdoor exercise unpleasant and even dangerous. Clients who run or hike in wooded areas should wear insect repellent and check for ticks after every workout.
And they should be aware of the symptoms of Lyme disease and other tick-borne illnesses.
Depending on the region, animals may be an added risk for those exercising in natural areas, and clients should be on the lookout for stray dogs, snakes, skunks, coyotes, and bears, all of which have been known to surprise unprepared exercisers.
Pearls of Wisdom
Many outdoor exercisers don’t pay attention to heat-related warning signs. Adults and children practicing or competing in sports or races in the summer heat are especially vulnerable because they may decide to “push” through the heat by giving into peer pressure during training or for the sake of winning.
The following tips may alleviate heat-related problems during summer exercise:
• Build tolerance to exercise during the heat through gradual acclimatization over two weeks, which involves starting with shorter workouts and gradually increasing duration as the body adjusts to hotter temperatures.
• Limit exercise to no more than one hour if it must be scheduled during the hottest part of the day.
• For prolonged exercise in the heat, carry water bottles and rehydrate regularly. Specially designed water bottles are available for runners, walkers, and cyclists to easily carry (eg, Camelbak brand).
• Exercise during the coolest part of hot summer days, early morning and late evening.
• Exercise in shaded areas.
• Wear sunscreen, insect repellent, and clothing that’s lightweight, light in color, and wicks away moisture.
• Consider water exercise as an alternative to land exercise.
Outdoor pools, lakes, and oceans provide fitness opportunities in the hot summer weather. Swimming laps and water aerobics burn calories and strengthen muscles with little risk of heatrelated injuries. Doing land exercise around accessible bodies of water, such as running on the beach or hiking trails around a lake, allows for a quick dip in the water to cool off.
• For children’s sports practices, ensure coaches are aware of heat-related risks and signs of heat-related medical problems in children. Children and teens shouldn’t be forced to continue training if they complain of being overheated.
Lastly, clients who just don’t enjoy exercising in the heat should exercise in an air-conditioned home or gym when temperatures climb above 80˚F.
All Fitness __ OUTDOOR EXERCIS
— Jennifer Van Pelt, MA, is a certified group fitness instructor and health care research analyst/consultant in the Reading, Pennsylvania, area.