If you’ve ever leaped into a pool for a cardio exercise, you understand just how much more challenging swimming can feel in comparison to running and cycling. Swimming may have appeared effortless when you were a child doing laps at camp; now, it’s astonishing how out of breath you can become after only a few minutes.

“Swimming is one of the finest workouts available,” says Rochelle Baxter, an Aaptiv master trainer, AFAA certified personal trainer, and triathlete. “It aids in fat burning, weight reduction, strength building, and overall health improvement.” Not to mention, swimming is low impact, making it an excellent choice for active recovery and injury prevention.

The rationale behind swimming being advantageous for you is that every time you pull, kick, or execute a stroke, you’re pulling against the resistance of the water, which is — obviously — significantly denser than air.

“This develops muscles and incinerates substantial calories,” says Baxter. “While you’re burning these calories, you’re also developing lean muscle, which means you will continue to burn calories throughout the day.” Calorie burn isn’t the sole factor, and swimming offers numerous other benefits, but if you’re curious about calculating your calorie burn, a few factors can assist you in estimating it after a workout.

How Many Calories Do You Burn Swimming?

To determine the number of calories you burn while swimming, first, you need to comprehend how scientists approximate the energy expended during physical activity. The measurement utilized is known as a MET (or metabolic equivalent), and it gauges the level of exertion relative to rest. When you’re lounging on the couch (also known as at rest), your body burns 1 MET, which is equal to 1 calorie per kilogram of bodyweight per hour.

If you understand how many METs an activity “costs” and know your body weight, you can calculate the calories burned during that activity. The good news is: no mathematical calculations are necessary. You can utilize an online calculator, which takes into account your weight and the duration of the exercise, to easily determine your calorie burn.

So, to calculate the calories burned while swimming, you’ll need to consider the type of stroke(s) you performed. While swimming, your body burns 3.5 METs (223 calories per hour) when treading water with moderate effort; 8.3 METs (528 calories per hour) for a medium-speed, vigorous crawl; and 13.8 METs (878 calories per hour) for butterfly stroke. (These estimates are for a 140-pound adult.)

For comparison’ sake, jogging would result in 7 METs (446 calories per hour) and bicycling would require 7.5 METs (477 calories per hour), although the METs and calorie burn for these activities vary depending on intensity.

What Factors Contribute to Your Calorie Expenditure While Swimming

How to Increase Caloric Expenditure During Swimming

However, do not become fixated on those figures. The number of calories burned in swimming is influenced by multiple factors, as Bianca Beldini, D.P.T., a physical therapist, USA Triathlon-certified coach, and certified Schwinn Cycling instructor, explains.

Your physique: “An individual who has a higher weight will utilize more calories compared to someone with a lower weight due to the greater energy required to move a larger body,” Beldini claims. (This factor is considered in the METs formula.) “Additionally, a larger body creates more surface area in the water, resulting in increased drag resistance. More resistance necessitates more energy to overcome, thus raising the heart rate and subsequently leading to heightened caloric expenditure.”

Your swimming speed: The speed at which you traverse through the water also impacts the number of calories burned while swimming. “Slower swimming results in lower energy output and, consequently, fewer burned calories,” notes Beldini. Therefore, the faster one swims, the more energy is consumed. Employing swimming aids such as pull buoys, paddles, parachutes, or bands to intensify resistance or drag will similarly amplify energy output, thereby increasing calorie burn.

Your swimming technique: Naturally, the stroke employed during swimming influences the number of calories burned. “Undoubtedly, the butterfly stroke is the most demanding and technically challenging,” Baxter states, explaining why it accounts for the highest calorie burn. When executing this stroke, one performs a dolphin kick while simultaneously driving the arms fully overhead, necessitating substantial engagement of the entire body’s muscles, particularly in the core and upper back. The crawl stroke follows closely in terms of calories burned while swimming. “With each stroke, there is also a corresponding kick!” notes Baxter. “This creates the ideal combination for significant caloric expenditure.” Breaststroke and backstroke yield comparable caloric outcomes. “Although these strokes are slower, proper technique can still result in calorie burning,” she adds.

For estimated calorie burn per stroke type, please refer to the list below. (Calculations are based on the weight of a 140-pound adult. Explore other MET estimates for swim strokes and speeds here and use this swimming calorie calculator to determine your personal calorie burn.)

• Treading water (moderate effort): 3.5 METs = 223 calories/hour
• Backstroke: 4.8 METs = 305 calories/hour
• Breaststroke: 5.3 METs = 337 calories/hour
• Freestyle or crawl (light or moderate effort): 5.8 METs = 369 calories/hour
• Freestyle or crawl (medium to vigorous effort): 8.3 METs = 528 calories/hour
• Freestyle or crawl (fast or vigorous effort): 9.8 METs =623 calories/hour
• Butterfly: 13.8 METs = 878 calories/hour

Techniques to Maximize Caloric Expenditure During Swimming

No matter your size, velocity, or stroke, the optimal method to incinerate more calories while swimming is engaging in intervals of strenuous endeavors interspersed with recovery time.

“A specimen interval set would resemble this: A 50m freestyle dash followed by a 10-second reprieve where your heart rate descends, recur five times in total,” says Baxter. Those high-intensity endeavors, with repose, strain your system far more than a constant state workout — and science demonstrates that HIIT burns 25 to 30 percent more calories, plus taps into the afterburn effect, which pertains to caloric burn following the completion of your workout. (P.S. You can incorporate calorie-burning intervals into your running workouts too.)

Are you prepared to give it a try? Subsequent occasion you’re desiring to incorporate a gentle cardio workout, submerge yourself in these swimming workouts for every level of fitness.

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