How Many Calories Does Swimming Burn?

Calories per minute = MET x 0.0175 x body weight (kg) Stroke and intensity MET values: Freestyle (front crawl), slow: MET 5.8 Freestyle, moderate: MET 8.3 Freestyle, vigorous/competitive: MET 10.0 Backstroke, moderate: MET 8.0 Breaststroke, moderate: MET 10.3 Breaststroke, vigorous: MET 13.8 Butterfly, moderate: MET 13.8 Treading water, moderate: MET 3.5 Water polo: MET 10.0 Recreational swimming (mixed): MET 6.0 Example: 70kg swimmer, breaststroke moderate, 40 minutes: Cal/min = 10.3 x 0.0175 x 70 = 12.62 kcal/min 40-minute session: 12.62 x 40 = 504.7 kcal

Breaststroke drag coefficient is higher than freestyle. The kick and pull cycle generates more resistance at each stroke, requiring more muscular force for the same speed. At the same speed (1:45/100m): Freestyle: approximately 8-9 MET Breaststroke: approximately 10-11 MET (25-30% more energy) Butterfly burns even more but is unsustainable for most: Elite butterfly swimmers can maintain 400m before fatigue Recreational swimmers typically manage 25-50m per set For maximum calorie burn per hour: Breaststroke and butterfly are most efficient per metre covered. For endurance and total session time: Freestyle allows longer sessions at moderate effort.

Cold water increases calorie burn through thermogenesis: Body must maintain core temperature at 37°C against cold water. At 28°C pool: minimal thermogenic effect At 18-20°C (open water): extra 100-150 kcal/hour for thermogenesis At 15°C or below: substantial thermogenic effect (but risky without acclimatisation) However, cold water also suppresses hunger regulation: Post-swim appetite is typically higher in cold water. The extra calories burned may be more than offset by extra eating. Standard pool temperature (25-28°C): thermogenic effect is minimal. Focus on stroke and duration, not water temperature, for calorie goals.