Furthermore its a full body workout, utilizing all of your major muscle groups.
Plus the water works like resistance weight training. Thus swimming combines the benefits of cardio with a light weightlifting program.
You can also alternate different kinds of swimming activities whenever you want to try something different. eg. Snorkeling!
Lastly swimming is FUN. So it makes it easier to stay motivated.
Below is a calories burned chart for a variety of swimming activities.
Activity,
Exercise or Sport (1 hour)
|
130
lb
|
155
lb
|
180
lb
|
205
lb
|
Swimming laps, freestyle, fast |
590
|
704
|
817
|
931
|
Swimming laps, freestyle, slow |
413
|
493
|
572
|
651
|
Swimming backstroke |
413
|
493
|
572
|
651
|
Swimming breaststroke |
590
|
704
|
817
|
931
|
Swimming butterfly |
649
|
774
|
899
|
1024
|
Swimming leisurely, not laps |
354
|
422
|
490
|
558
|
Swimming sidestroke |
472
|
563
|
654
|
745
|
Swimming synchronized |
472
|
563
|
654
|
745
|
Swimming, treading water, fast, vigorous |
590
|
704
|
817
|
931
|
Swimming, treading water, moderate |
236
|
281
|
327
|
372
|
Water aerobics, water calisthenics |
236
|
281
|
327
|
372
|
Water polo |
590
|
704
|
817
|
931
|
Water volleyball |
177
|
211
|
245
|
279
|
Water jogging |
472
|
563
|
654
|
745
|
Diving, springboard or platform |
177
|
211
|
245
|
279
|