Same distance, same person, different stroke — calorie burn varies 2×. Here's how to estimate yours.
Google this topic and you will get a hundred answers, half of them wrong. Here is the version that holds up. Same distance, same person, different stroke — calorie burn varies 2×. Here's how to estimate yours.
Freestyle ~450 kcal, breaststroke ~500, butterfly ~700, backstroke ~400.
Technique efficiency. Beginners burn more (less efficient); pros burn fewer at same pace.
Optical heart-rate is unreliable under water; chest straps work better.
Does swimming burn more than running? Per hour roughly similar, per km usually less because you cover less distance per hour.
Why am I hungry after swimming? Cold water + buoyancy means perceived effort is low — actual burn is high, so hunger spikes.
The math is the easy part. Acting on what it tells you is where the real win lives.