Swimming is a cardiovascular activity that has the potential to help you shed fat – especially if you do it regularly. However, it doesn't work well for everyone, and may be less effective than other types of aerobic exercise, such as brisk walking or running. Several factors come into play when it comes to the fat-burning potential of swimming.
Swimming can help you burn fat, but it does not work as well as other activities for many people. That's because you need much more skill to do it than other aerobic workouts such as walking or cycling. Most people cannot swim long enough or fast enough to eliminate a significant number of calories, according to "The Fat-FreeTruth" by Liz Neporent and Suzanne Schlosberg. If you tire after 20 minutes, for example, you'll only burn about 100 calories during your workout.
If you don't have good swimming technique that helps you glide along the pool, there is a silver lining. When you have a less-efficient swim stroke, you actually use more energy to move through the water, which increases your calorie burn during the time you are able to slog along, say Paul Goldberg and Matt Fitzgerald, authors of "The Lean Look." For example, if you don't attain proper body rotation with each swim stroke, you create more drag, which makes you work harder. Kicking too hard also creates drag.
Once you get your technique down, you may need to work harder or longer at it to burn the same number of calories you would walking at a brisk pace or running, according to "The Ultimate Fat Loss Guide" by Shondelle Solomon-Miles. That's because the water's buoyancy is apt to decrease your exercise intensity. However, if you love to swim, stick to it. You are more likely to work out consistently when you're doing something you enjoy, and consistency is key to fat-burning success, Solomon-Miles notes.
If you have good swimming technique, the type of swimming you do will affect your fat-burning potential. If you are a distance swimmer, as opposed to a sprint swimmer, you will burn more fat during your workouts. That's because distance swimmers have a higher percentage of slow-twitch muscle fibers, which are better suited to fat metabolism than fast-twitch fibers because they have more fat stored within them, says "Swimming Fastest" author Ernest W. Maglischo. About half of the fat that is metabolized for energy as you exercise comes from your slow-twitch fibers. The other half comes from adipose tissue. Slow-twitch muscle fibers also transport fat from adipose tissue quicker than fast-twitch fibers and have more mitochondria where the fat can be metabolized. During a slow-and-steady two-hour training session, fat metabolism is likely to supply between 30 and 50 percent of the energy you use. Fast-twitch fibers used during sprinting, in contrast, are more reliant on glucose and the form of glucose that is stored in your body, called glycogen. Also, glycogen supply declines significantly after your first hour of swimming forcing your body to turn to fat metabolism for energy.