calorie burning - *** vs freestyle

Typically breaststroke is pretty inefficient compared to freestyle, so for a given distance, the swimmer will need to expend more energy in that stoke compared with freestyle. But it depends on how far you swim each stroke.

Competitive breaststroke uses THE most energy, more than free, back and even fly.

Disagree unless the freestylist/backstroker heartrate is significantly less than the breastrokers. Same heartrate/same time = same calories spent regardless.

LindsayNB: Yes, I'm not arguing which stroke is more or less "not" efficient. 'Tween you and I, we know which are easier to utilize. I think you've re-stated my same argument in different terms. Yes? No?

Definitely the a 52 second breaststroke over 100 m will burn more calories than the 52 second free or back. The reason for this is the repeated deceleration that takes place when the arms and hands recover underwater. The stroke also presents a less streamline body against the water, increasing drag. To overcome it and swim at the same speed as a freestyler, the breaststroker will have to use more energy. For a detailed scientific discussion (at least the most complete I've seen) you could check out the text by Ernest Maglischo, titled "Swimming Fastest".

Certainly depends on the specific condition of the individual's muscle groups (adapted to one stroke or the other)

Heartrate is likely pretty well correlated with level of effort and work done, but it doesn't offer any predictive power in this context, it's more of a measurement than a cause. It is well established that breaststroke is the least efficient of the competitive strokes and therefore takes more energy to swim the same distance at the same speed or alternately and more frequently results in lower speed for the same energy expended. In addition to being less streamlined and accellerating and decellerating more and the underwater recovery, you expend a lot of energy pushing water in directions perpendicular to the direction of travel.

COMPETATIVE Breaststroke uses the most energy because you REALLY use the big muscles of your legs and that burns more energy than the comparitively smaller muscles of your upper body(and you use them too in breaststroke as well as your core,it's a better total body workout.) I say competative breaststroke in contrast to headup reststroke which you see many people do at some pools,generally when they step into your lane obliviously when you are in the middle of a set.

I'd bet it's a heartrate and time function relation. Doesn't matter what stroke or muscle group(s) being worked.

This makes sense, if heart rate is any indicator. I have proven this to myself by wearing a heart monitor while swimming. My heart rate gets higher doing breaststroke sprints than it does while sprinting any other stroke.