Swimming is great for fitness and weight loss, but it can be difficult to know how long you should swim to lose weight, see body shape improvements, and feel fitness benefits.
As a general rule, the duration of your swim will depend on your fitness and weight loss goals. For example, if you weigh 75kg, and swim breaststroke for 40 minutes, covering a distance of 1000 meters, you will burn 541 calories on average.
Here is a detailed breakdown of how long you should swim for, with times, distances and calories burned, taking into account your swim stroke style and average body weight.
How Many Hours Should I Swim To Lose Weight?
| Swim Stroke | Body Weight | Time Swimming | Distance | Calories Burned |
| Breaststroke | 75kg | 40 Minutes | 1000 Meters | 541 |
| Front Crawl (Freestyle) | 75kg | 40 Minutes | 1000 Meters | 525 |
| Butterfly | 75kg | 40 Minutes | 1000 Meters | 725 |
| Backstroke | 75kg | 40 Minutes | 1000 Meters | 499 |
How many calories you burn when you swim depends on the following factors:
- Your Body Weight – The heavier you are, the more calories you will burn.
- Swim Stroke Type – Some swim stokes will burn more calories than others, with the butterfly being the best workout for burning the most calories.
- Intensity Of Swim – The level of effort and intensity exerted in your swim will contribute to the amount of calories you burn. For example, an intense high energy breaststroke will burn more calories than a calm leisurely swim.
| Body Weight | Swim Stroke | Time Swimming | Distance | Calories Burned |
| 45kg | Breaststroke | 40 Minutes | 1000 Meters | 324 |
| 50kg | Breaststroke | 40 Minutes | 1000 Meters | 361 |
| 60kg | Breaststroke | 40 Minutes | 1000 Meters | 433 |
| 65kg | Breaststroke | 40 Minutes | 1000 Meters | 469 |
| 70kg | Breaststroke | 40 Minutes | 1000 Meters | 505 |
| 75kg | Breaststroke | 40 Minutes | 1000 Meters | 541 |
| 80kg | Breaststroke | 40 Minutes | 1000 Meters | 577 |
| 85kg | Breaststroke | 40 Minutes | 1000 Meters | 613 |
| 90kg | Breaststroke | 40 Minutes | 1000 Meters | 649 |
| 95kg | Breaststroke | 40 Minutes | 1000 Meters | 685 |
| 100kg | Breaststroke | 40 Minutes | 1000 Meters | 721 |
| 110kg | Breaststroke | 40 Minutes | 1000 Meters | 793 |
| 120kg | Breaststroke | 40 Minutes | 1000 Meters | 865 |
| 130kg | Breaststroke | 40 Minutes | 1000 Meters | 937 |
| 140kg | Breaststroke | 40 Minutes | 1000 Meters | 1009 |
I calculated the above swim times and calorie burn data using the following formula, so if you want a number for your exact bodyweight, swim stroke and swim duration, use this formula to calculate your own personal stats:
Total Calories Burned = Duration (in minutes) x (MET x 3.5 x weight in kg) / 200
Where MET is the metabolic equivalent that scientists have already calculated as follows:
| Swim Stroke | MET [Metabolic Equivalent] |
| Breaststroke | 10.3 |
| Front Crawl | 9.8 |
| Backstroke | 9.5 |
| Butterfly | 13.8 |
Which Stroke Burns Most Calories?
As a general rule, the butterfly is the swim stroke that burns the most calories, as it requires the most physical effort to perform.
However, the butterfly is a very advanced stroke and is not known by many beginner or intermediate swimmers.
After the butterfly, the next best swim stroke for burning calories is the breaststroke.
Breaststroke is considerably easier to learn and burns a lot of calories as the legs, torso and arms are doing a significant amount of work in the water.
If you would like more detail about the differences between beginner, intermediate, and advanced swimmer times, take a look at my article, which covers the topic in a little more depth:
Is Swimming Good For Fitness And Weight Loss?
From my personal experience, I have found swimming excellent for general fitness. However, for weight loss, I have found that eating a well-balanced diet with reduced carbs and sugars alongside my swimming to be the most effective for weight loss.
It is well documented that swimming is fantastic for fitness. As a low impact, high cardio sport, it is an amazing workout for our heart and lung health.
The fitness benefits of swimming include:
- Excellent cardio workout, so good for health and lungs.
- High calorie burning exercise to maintain weight
- Helps tone muscles
- All over body workout
- Low impact so good for joints.
But how good is swimming for weight loss?
Many experts highlight that swimming is a wonderful calorie-burning exercise, and from the tables of figures mentioned previously in this article, we can see that.
However, I want to share my personal experience of using swimming for weight loss, because I swam for months and months and only lost 5lbs.
Here are the mistakes that I made, which reduced the weight calorie-burning impact of my swimming.
- Because I swam a lot in the morning and did not have a substantial breakfast, I was often hungry so I over ate after my workout. Therefore, I gained weight.
- I often drank high sugar energy sports drinks, thinking that they were fueling my energy, but they were just filling me with sugar and empty calories. Therefore, I gained weight.
- I would often indulge in a high carbohydrate meal, such as pasta or baked potatoes, thinking that this was healthy, however the excess carbs were just filing me with calories. As a result, I gained weight.
- I would often swim for a long time but at a slow to leisurely pace. To burn calories and get a good workout, you need to increase the intensity and get your heart pumping.
Tips For Swimming To Lose Weight
Based on a combination of my experience of swimming to lose weight and that of seasoned experts and gurus such as Dr Michael Mosley, here are my honest top tips for swimming to lose weight.
1 – Increase Swim Intensity
By increasing your swim intensity, i.e. the amount of effort you exert when you swim, you will burn more calories.
Not only that, recent research made popular by Dr Michael Mosley, has shown that if you want to lose fat, intensity is the key.
Many studies have shown that conventional, low-intensity exercise, like a leisurely swim, rarely leads to weight loss. To lose weight, you have to increase the swim intensity.
Don’t panic, the good news is that you do not have to swim like a crazy person for 40 minutes! You can do short bursts of high intense speed at full pelt.
According to Dr Michael Mosley, you can swim (or any exercise) for as little as 10 minutes a day, three times a week, which includes rests, with excellent weight loss and fitness benefits if you incorporate high-intensity speed intervals in your exercise.
Here is an example of a high-intensity fat-burning exercise for the pool that takes less than 10 minutes to complete.
- Start with a gentle warm up by swimming slowly up and down the pool for 2 minutes.
- Gently up the intensity to a moderate pace.
- When you are ready, swim 25 meters (typically one pool length) as fast as you can.
- Rest and swim a couple of more gentle lengths.
- When ready, do another one pool length sprint.
- Rest
- Complete 4 sprints in total if you can, with rests in between.
- Finish with another 2 minutes of gentle swimming to warm down.
To learn more about HIT (High-Intensity Training) and the amazing health benefits, I recommend Dr Michael Mosley’s book, Fast Exercise: The simple secret of high-intensity training: get fitter, stronger and better toned in just a few minutes a day
2 – Mix Up Your Swim Strokes
To avoid injury because of repetition, reduce boredom, and give a full-body workout, it is beneficial to mix up your swim strokes and use a combination of front crawl, backstroke, breaststroke and butterfly.
Not only does this work for all muscle groups, but it will also keep your workouts interesting and reduce the risk of injury because of the overuse of one set of muscles.
3 – Create A Swim Workout Plan
It can really help to have a swim workout plan so you get the most out of every swim.
For example, the high-intensity swim workout mentioned previously is really great way to ensure you leave the pool with your heart rate pumping and calories burning.
I like to have alternative plans to accommodate how busy the pool is, as some days I have the pool to myself and other days I have to work around other swimmers.
On a quiet to moderate busy day in the pool, I will complete the HIT (High-Intensity Training) workout mentioned previously.
On busy days in the pool, I like to pick a corner of the deep end tread water intensely for a long time to build strength or water jog / walk to build muscle tone.
4 – Don’t Drink Calories. Stick To Water
When I first started swimming regularly, I would drink sports drinks to give me energy and to keep me hydrated.
It is really important to drink lots and keep hydrated when you swim. However, I found it was best to stick to water for weight loss.
The sports drinks I was consuming were full of sugar, glucose, and empty calories, which just replaced the calories I had just burned in the pool.
Water does not have any calories, so to keep hydrated while swimming for weight loss, skip the sports drinks and stick to water.
5 – Join A Swim Aerobic Class
Aqua aerobic classes can be lots of fun, have great social benefits and be an excellent way to burn calories in the water.
When an aqua aerobics class is fun, it is a lot easier to find the motivation to exercise.
If you are not water confident or are not sure how to work out by yourself in the pool, joining an aqua aerobics class can be a fantastic way to get into the pool.
6 – Be Swim Calorie Smart
When I first started swimming, I would often treat myself to a lovely morning latte to congratulate myself on my early morning swim.
Although this was a wonderful routine and kept me super happy, this was a bad habit for weight loss.
Being aware of how many calories are in our favourite snacks and how many hours of swimming you would need to work off those snacks can be a real eye-opener!
Here is a list of my favourite snacks and how long I would have to swim front crawl to work off the calories gained from these snacks.
| Snack | Calories | How Long Swimming To Burn These Calories |
| Tall Latte | 180 | 20 Minutes |
| Banana | 90 | 10 Minutes |
| Smoothie | 150 | 15 Minutes |
| Large Chocolate Muffin | 480 | 1 Hour |
| Chocolate Bar | 230 | 25 Minutes |
When I saw it would take me 1 hour of swimming front crawl to burn off a large chocolate muffin, I realised what snacks I should definitely avoid.
The one large chocolate muffin would undo all my morning’s workout in the pool, but a banana can boost recovery and with only 90 calories, it is a far better choice for a post-swim snack when I am trying to shed those extra pounds.
7 – Incorporate Dry Land Exercises
Getting to the pool every day can be a challenge. However, it is possible to incorporate dry land exercises into your workout routine.
Using resistance bands at home to tone muscle and keep your swimming muscles in shape is a great way to maintain swimming fitness without actually getting in the water.
Power chords or resistance bands with hand paddles can help give a great muscle workout, strengthen muscles and burn calories.
8 – Avoid The Post Swim Carbs
This is a trap I fell into and it negatively affected my swimming weight loss goals.
After swimming, like many people, I get super hungry. I used to indulge in a big plate of pasta post-swim workout, thinking this was a healthy lunch.
However, for weight loss, I have learned to avoid carbohydrate-heavy meals such as pasta and potatoes.
To get the most out of your workout and burn fat, avoid loading up on carbs.
I learned this from the book, The Fast 800: How to combine rapid weight loss and intermittent fasting for long-term health, by Dr Michael Mosley.
You don’t have to go as extreme as the ketogenic diet, and Dr Mosley’s book outlines a healthy low-calorie, low-carbohydrate diet to encourage the body to burn up glucose quickly and start burning fat.
Used with swimming exercise, this healthy, low-carbohydrate Mediterranean-style diet by Dr Michael Mosley really works and works fast.
The secret is to reduce carbs, so don’t let the post-swim munchies take hold! Opt for high-protein meals instead.
Final Thoughts
The duration of your swim session depends on your personal swim goals, weight goals and fitness goals.
How many calories you burn as you swim will be determined by the type of stroke you are doing, how intensely you are swimming, and for how long.
High-intensity swimming, or swimming as fast as you can with maximum effort, will burn the most amount of calories.
Research has found that you can swim for as little as 10 minutes per session, three times a week, to see fitness benefits as a result of high-intensity swim training.