Cycling Versus Swimming for Cardio

Swimming and cycling are both excellent forms of aerobic exercise, particularly for people who don't like to run. Cycling has the edge in convenience; it's easier for most people to hop on a bike than it is to find a pool or a natural water body where they can do a swim workout. You can ride a bike on the roads, in the gym or even in your living room if you have a stationary bike or a trainer that allows you to cycle indoors.

Cycling is a convenient way to exercise. (Image: Gilitukha/iStock/Getty Images)

The Calorie Comparison

While cycling primarily works the quadriceps, swimming is more of an all-body exercise, working muscles in your back, shoulders, chest, core and legs. Swimming burns a lot of calories, too -- a 154-pound person swimming a slow freestyle (front crawl) stroke will burn 510 calories an hour -- nearly as much as the 590 calories the same person would burn cycling faster than 10 mph. Bump the pace up to a faster freestyle, and you'll burn more than 700 calories an hour.

Matters of the Heart

In both activities your heart rate when exercising hard may be slightly less than it would be for running at the same intensity. In swimming, the heart rate is lower because the water has a cooling, buoyant and compressing effect that makes it easier for your heart to deliver oxygen to your working muscles. Cycling is also a weightless sport, which may explain why researchers have found that a trained triathlete's maximum heart in cycling is six to 10 beats per minute slower than when they are running.

Monitoring the Effort

In addition to its convenience, athletes find it's easier to monitor their heart rate on the bike than in the pool. Cyclists can check their heart rates easily with a chest transmitter and a monitor strapped to their handlebars. Swimmers, meanwhile, can only check their heart rates when they pause from swimming.

Workout Structures

Effective swimming and cycling workouts often use similar training approaches to achieve their cardio benefits. Typical swimming workouts include warm-ups, drills, a main set that can include hard intervals or sustained hard efforts at a high heart rate, and a cool-down. Cycling workouts often include planned surges or hard intervals, hill repeats and other methods designed to train the body to be able to work out aerobically at higher and higher heart rates.

Take Your Pick

The best exercise is one you like doing, because you're more likely to continue doing it and enjoying the health benefits. Both cycling and swimming allow you to elevate your heart rate and sustain that effort, which is what an effective cardio workout is meant to do. While cycling is a skill most people can quickly acquire, swimming may take longer to master. Nevertheless, many swimming activities, including sidestroke, backstroke, water jogging and treading water - all burn calories at a high rate, so it's not hard to find a water activity that matches your abilities.