Maintaining a healthy body weight is one of the primary reasons many individuals start an exercise program, and it usually involves managing two key variables: energy intake and energy expenditure. Physical activity can include both exercise and non-exercise activity thermogenesis (NEAT), which is the amount of energy used to perform the normal activities of daily living such as walking to perform errands or taking the stairs. The human body is extremely efficient in that any excess energy not used to fuel physical activity or bodily functions like digestion or cognition will most likely be stored as fat. Therefore, for many clients who want to achieve and sustain a healthy bodyweight, one important purpose of exercise is to burn fat as a primary source of fuel in an effort to reduce the amount stored in the body.
Muscle cells metabolize adenosine triphosphate (ATP) from either carbohydrates or fats to produce the energy for physical activity. Glycolysis converts glycogen (stored form of carbohydrates) into ATP either with or without oxygen. Lipolysis is the process of metabolizing ATP from fat molecules (lipids) in the presence of oxygen.
If exercise for the purpose of fat burning is important to a client, lower-intensity workouts that rely on lipolysis should be included in the exercise program. The Talk Test can be used to identify whether a client is metabolizing fat or carbohydrates as the primary source of fuel. During lower-intensity exercise (and while at rest) muscle cells rely on lipolysis for ATP; however, as the intensity of activity increases, muscle cells need a more rapid source of energy and begin using glycolysis to produce the necessary ATP. Carbon dioxide (CO2) is a byproduct of glycolysis and explains why the breathing rate speeds up as the intensity of exercise increases; the lungs are working faster to bring oxygen in as well as pushing CO2 out of the body, thus making it more difficult to talk.
When a client can talk in complete sentences while exercising, they are most likely relying on lipolysis for ATP production; however, if a client can only speak in short fragments or individual words, glycolysis is the probable source of ATP. Exercise programs in which the intensity challenges a client to breathe faster than normal but still allows them to talk in complete sentences could help to optimize fat burning. Teaching clients how to monitor their ability to speak could help them to identify when they are most likely exercising at a level of intensity where fat is the primary source of energy. (Follow this link to learn more about the Talk Test and how to apply it to your workout programs).
There are tangible benefits to exercising outdoors; as the weather warms up and it becomes more enjoyable to be outside, you can add variety to your clients’ exercise programs by incorporating more outdoor workouts. Listed below are seven options for designing outdoor workouts that could help clients focus on burning fat to achieve a healthy body weight.
- A strength-training circuit featuring body-weight exercises can help to build strength while burning fat, and a park or playground offers options for a challenging but fun exercise circuit. Identify a location that includes various items such as benches, low walls or playground equipment, which can be used for body-weight exercises such as jumps, step-ups, triceps dips, push-ups and modified pull-ups. Identify a number of stations that can be used for body-weight exercises, have clients perform a number of repetitions and then move to the next station for another exercise. Alternate between upper- and lower-body movements; for example, have the client perform step-ups on a low-wall followed by triceps dips on a bench, or body-weight squats followed by push-ups followed by jumps up to a park bench.
- Another option at a park or playground is to encourage clients to put down their phones and play with their children. Playing games such as tag or variations of different sports can be an effective method for exercising. Help clients identify different games they can play with their kids, which makes exercise an activity for the entire family. The additional benefit is that everyone will be having so much fun, they won’t realize they are actually exercising.
- Encourage your clients to try doing walk-run intervals. Coach them how to monitor their breathing rate and to run to a point where they start getting out of breath and then walk until their breathing is completely under control. Have them track the lengths of time it takes to get breathless and to recover their breathing. Over time, they will be able to run faster before getting out of breath and they will recover more quickly, both of which are indicators that their fitness is improving.
- Roller skating has made a resurgence and provides a great option for being active. Skating has minimal surface friction when compared to the ground contact of walking or running, so the intensity could be considered low-to-moderate, which is optimal for burning a greater percentage of calories from fat. Plus, it uses a number of lower-body muscles, which helps to increase overall energy expenditure. Encourage clients to take proper precautions by wearing recommended safety gear and staying on approved pathways.
- Bicycling, like roller skating, can be an effective, low-impact method of fat burning, especially when moving on relatively flat terrain at a consistent, comfortable rate of speed. To optimize the fat-burning response, remind clients to keep moving at a pace where breathing is faster than normal, but they can maintain the ability to speak in complete sentences. Again, encourage clients to use bike paths that are away from automobile traffic and wear proper protective gear such as helmets and high-visibility clothing for optimal safety.
- Hiking local, off-road trails are a great option for an activity that can elevate the heart rate without becoming out of breath. Hiking trails are also a great way to explore recreational areas while experiencing nature and learning more about the local area. Help clients identify local hiking trails that are within their fitness level and ability and encourage them to make weekend hikes an activity for the entire family.
- While muscles metabolize primarily fat to fuel activity at lower intensities, high-intensity interval training (HIIT) can allow more calories to be burned in a minimal amount of time. Research has found that a Tabata interval of body-weight exercises can produce similar results to running on a treadmill. Have a client do a four-minute Tabata interval that alternates between body-weight squats and push-ups (or spider-man planks) for eight, 20-second intervals. While HIIT relies primarily on anaerobic glycolysis (burning carbohydrates without oxygen) for energy, it could help burn more calories in less time.
Low-to-moderate intensity exercise that relies on lipolysis is also a great option for active recovery the day after a really hard workout. A recovery day does not mean skipping a chance to exercise; for example, a hike the day after a really hard strength workout is a great way to help muscles recover while providing an opportunity to burn fat. It is important to note, however, that even though exercise performed at a lower intensity (below the talk test threshold) does burn a greater percentage of calories from fat, it does not lead to a greater number of total calories burned from fat when compared to higher-intensity exercise. Therefore, incorporating the seven steps above can lead to positive results because they include both moderate- and higher-intensity exercises. The idea that there is a specific “fat-burning zone” is true in the sense that lower-intensity exercise will burn a greater percentage of calories from fat, but for weight loss it is the total amount of calories that is most important.
As the seasons change and the weather begins to warm-up, clients who have been sweating indoors all winter will be looking for opportunities to be outside as much as possible. Providing clients with these options for outdoor workouts can help to build your value as a health and exercise professional, while also helping to ensure they remain active every day which is one of the most important components of long-term success from exercise.