Both swimming and running are excellent forms of cardio that can help burn fat and calories. But is one better than the other when it comes to fat loss? There are a few key factors to consider.
Generally speaking, running burns more calories per minute compared to swimming. According to Harvard Health, a 155 pound person burns around 367 calories running at a 5 mph pace for 30 minutes. The same person would burn around 298 calories swimming freestyle at a moderate pace for 30 minutes.
However, the water provides extra resistance when swimming, so you are working harder to move your body. This leads to continued calorie burn after you get out of the pool. One study showed that swimming burned an average of 30% more calories in the 24 hours after exercise compared to cycling.
Building muscle is key to boosting your metabolism and burning more fat, both during exercise and at rest. Running uses more muscles throughout your lower body to propel yourself forward. Swimming uses your upper body, core, and legs to a lesser extent.
Most experts agree that running builds more muscle mass overall. A study comparing muscle thickness after 8 weeks of swim vs run training found that running led to significantly more increases in rectus femoris thickness.
Weight Bearing vs Low Impact
Running is a weight bearing and high impact exercise. Your feet, legs, and joints are directly impacting the ground with each stride. This helps strengthen bones and connective tissue.
In contrast, swimming is low impact and non-weight bearing. This makes it a gentler option for those with existing joint pain or injuries. But it may not provide the same bone strengthening benefits as running.
Both running and swimming will improve your cardiovascular fitness. One study compared VO2max gains after 8 weeks of swim training versus run training in young males.
They found very similar improvements in VO2max, a key measure of cardiovascular endurance, between the two groups. This suggests swimming and running can produce comparable cardiovascular benefits.
Fat Burning Zone
The fat burning zone refers to the % of calories burned from fat during exercise. This zone occurs at around 55-70% of your max heart rate.
Running at a moderate pace tends to keep your heart rate in the fat burning zone. Swimming also keeps you in this zone, unless you are doing very high intensity swimming sprints.
So in terms of time spent in the fat burning zone, swimming and running are likely comparable.
Running likely burns more total calories and builds more muscle mass compared to swimming. This may give it a slight edge for fat loss over time.
However, swimming provides an excellent low-impact cardio option that also improves cardiovascular endurance. It allows you to work out longer and more frequently compared to higher impact activities like running.
For optimal fat loss, the best option is to incorporate both running and swimming as part of a comprehensive fitness program. Taking a multi-modal approach combines the unique benefits of each exercise.
Additional Factors to Consider
There are a few other factors that influence whether swimming or running is better for fat loss:
The harder you swim, the more calories and fat you will burn. Interval training, sprints, and using paddles or floats can all help increase swimming’s calorie burn to match running.
Total calorie expenditure also depends on the duration of exercise. The longer you swim or run, the more fat you will burn overall.
Your cardiovascular fitness, muscle mass, and efficiency at each exercise impacts calorie and fat burn. Those adapted to running may burn more calories with it vs swimming, and vice versa.
No matter how much you exercise, you can’t out-train a poor diet. Without being in an overall calorie deficit, fat loss is unlikely.
To lose fat, aim for a moderate calorie deficit, eat plenty of protein, and include both swimming and running as part of a healthy lifestyle.
Further Research Comparing Swimming vs Running
Here is a summary of some key scientific studies that provide additional insights on how swimming and running compare for fat loss and body composition changes:
Study 1: 8 Weeks of Swimming vs Running Training in Young Males
- 24 healthy and untrained young males were randomized into swim training, run training, or a control group
- Swim and run groups completed 3 sessions per week for 8 weeks
- No significant differences found between groups for changes in body mass, body fat %, waist circumference, or hip circumference
- Conclusion: Swimming and running led to similar body composition improvements
Study 2: 12 Weeks of Swimming vs Running in Obese Adults
- 40 obese adults split into swim training, run training, or control groups
- Trained 3 days per week for 12 weeks
- Run group lost significantly more body mass and waist circumference compared to swim and control
- No significant difference between run and swim for body fat % decrease
- Conclusion: Running led to slightly better reductions in body mass and waist circumference
Study 3: 1 Year Exercise Intervention with Swimming vs Running
- Overweight adults prescribed swimming, running, or no exercise for 1 year
- Swim and run groups completed ~3 sessions per week
- Swimming and running led to significant reductions in body weight and body fat
- No significant differences between swim and run groups
- Conclusion: Similar body composition improvements between swimming and running
Sample Swimming vs Running Weekly Schedule
To get the benefits of both swimming and running, a balanced training schedule could look something like:
30 minute swim
30 minute run
30 minute run
30 minute swim
60 minute run
This totals around 2.5 hours of cardio per week split between swimming and running workouts. Adjust the duration, frequency, and intensity of workouts based on your fitness level and goals.
Nutrition for Fat Loss
To complement your swimming and running regimen for optimal fat burning, be sure to focus on healthy nutrition:
- Maintain a moderate calorie deficit of 500-1000 calories daily from your maintenance needs
- Consume 0.5-1g of protein per pound of bodyweight to help retain muscle mass
- Limit processed foods, sugar, refined carbs, and unhealthy fats
- Eat plenty of fruits, vegetables, lean protein, whole grains, and healthy fats
- Stay well hydrated before, during, and after exercise
With the combination of effective cardio exercise and proper nutrition habits, you can maximize your fat burning potential.
For most people, the best approach is to incorporate both swimming and running as part of a comprehensive fitness program for fat loss. This allows you to reap the unique benefits of each form of cardio exercise.
Running likely burns more total calories and builds more muscle mass. But swimming is gentler on joints while providing comparable cardiovascular benefits.
No single form of exercise will be optimal for every individual. Try varying swim and run workouts to find the most effective routine that keeps you active and supports your fat loss goals.