Swimming for Weight Loss: Calories by Stroke and a Plan for Beginners

Swimming is one of the few workouts many heavier people, or people with sore knees, can keep up for 30 to 45 minutes. It also has a reputation as a weak fat burner, partly because swimmers often come out of the pool starving. Both things are true. This guide gives the calorie numbers by stroke, what the trials found, why the hunger matters, and an 8-week plan in pool lengths for adults who can swim a little.

Is swimming good for weight loss?

Yes, modestly, and in the few trials that compare them it may work about as well as land exercise. A 2018 systematic review and meta-analysis in Sports Medicine reviewed 29 controlled studies of pool swimming in non-elite swimmers. Compared with no exercise, swimming had significant favourable effects on body mass (a mean difference of 2.90 kg), body fat percentage (1.92 percentage points lower) and lean mass (1.96 kg more). The authors concluded swimming may offer robust benefits for fitness and body composition, with effects that may be comparable to other exercise modes.

The best head-to-head trial is the Sedentary Women Exercise Adherence Trial 2, published in Metabolism in 2010. It randomised 116 inactive women aged 50 to 70 to swimming or walking, three moderate sessions a week for 12 months. After 6 months the swimmers had smaller waists (80.8 vs 83.1 cm) and, at 12 months, relative to walking, swimming reduced body weight by 1.1 kg. That is a real edge, but a small one. Neither study was a diet trial, and the weight changes were small, which is why the fat loss goal page starts with the calorie deficit.

How many calories does swimming burn?

Energy cost is measured in METs. The 2024 Adult Compendium of Physical Activities defines 1 MET as about 1.0 kcal per kg of body weight per hour, so an estimate is METs × weight in kg × hours. The table uses the Compendium's water activities values; the original yards per minute are converted to metres, and the calorie columns are our arithmetic.

To picture those paces in a 25-metre pool: 27–41 metres a minute is a length every 37 to 55 seconds, 46 metres a minute is a length in about 33 seconds, and 69 metres a minute is about 22 seconds (our conversions). Most adult beginners start in the slow row. The Compendium paper itself says its values are a starting point and do not reflect precise individual energy use. These are also gross figures that include the roughly 1 MET you would burn sitting still, so don't eat back every calorie a watch shows.

Is swimming or the gym better for weight loss?

Per minute, steady lap swimming burns about as much as easy running and more than a typical weights session, but the gym builds muscle in a way swimming does not aim to. The comparison below uses Compendium values from the running and conditioning exercise pages.

So the choice is not swimming or the gym. Swimming gives you a large, joint-friendly calorie burn; lifting helps you keep muscle while you eat less. The WHO 2020 physical activity guidelines ask adults for 150–300 minutes of moderate aerobic activity a week and muscle-strengthening on 2 or more days, and swimming covers only the first half of that. Our guide to steady cardio, intervals and strength for fat loss explains how to mix the three.

Why am I so hungry after swimming?

You are not imagining it: swimming tends to raise how much people eat afterwards. In a 2020 crossover study in Appetite, 32 young adults did 60 minutes of hard swimming, hard cycling or rest. Swimming increased the amount they ate at a buffet 30 minutes later compared with resting, from 3,259 to 3,857 kJ on average; intake after cycling rose by less and was not significantly different from rest.

A 2023 systematic review and meta-analysis of 8 studies found a single session of water-based exercise increased ad libitum energy intake by 330 kJ (about 79 kcal, our conversion) compared with not exercising, with no significant difference between water and land exercise. Exercising in cold water at 18–20 °C raised intake by 719 kJ (about 172 kcal) more than water at 27–33 °C. The authors advise anyone focused on weight to be mindful of the tendency to eat more in the hours after a water session, particularly in cold water.

Is swimming good for belly fat?

Swimming can help you lose belly fat as part of overall fat loss, but no stroke targets the stomach. In the 2010 Metabolism trial, swimmers had smaller waists than walkers after 6 months. The 2018 Sports Medicine review, however, found a pooled analysis of two studies in adults with high blood pressure showed waist circumference 4.03 cm higher with swimming than control. The fair reading: waist size follows total fat loss, which follows your calorie balance. Our belly fat training guide covers why spot reduction doesn't work and what does.

Is swimming good if you have sore joints or a lot of weight to lose?

Water carries much of your body weight, which is why many people who struggle to walk far can swim for half an hour. The CDC's Swimming and Your Health page says people are able to exercise longer in water without increased joint or muscle pain, and that this has been especially helpful for people with arthritis. For someone with a high body weight, that means more minutes of real effort in the week, which is what drives the calorie numbers above.

If knees are the issue, our guide to knee pain and exercises to avoid explains what to clear with a clinician first. In the pool, if a kick hurts, switch strokes: freestyle or backstroke with a small, gentle flutter kick, or a pull buoy between the thighs, lets you keep swimming while you get it checked. If you are starting from a high weight, online personal training for overweight beginners shows how to build the land side gently.

How long should I swim to lose weight?

Aim for 30 to 45 minutes, 3 to 5 times a week, which lands inside the WHO range of 150–300 minutes of moderate activity. As an example of the arithmetic: an 80 kg beginner swimming slow freestyle for 40 minutes, three times a week, burns roughly 930 kcal gross (5.8 METs × 80 kg × 2 hours), or about 770 kcal above resting. That helps, but it is a fraction of a week's food, so the deficit still comes mostly from the kitchen.

For a realistic pace, the CDC says people who lose weight at a gradual, steady pace of about 1 to 2 pounds a week (roughly 0.5 to 1 kg) are more likely to keep it off. Find your maintenance calories with the TDEE calculator and eat a little under them.

What does an 8-week swimming plan for beginners look like?

This plan assumes a 25-metre pool, three sessions a week and that you can already swim one length without stopping, in any stroke. Easy means you could say a full sentence at the wall; steady means a few words. Start each session with 2 easy lengths and finish with 2 easy lengths or some floating and stretching. Rest at the wall between sets; the rest is part of the plan, not a failure.

1. 1

   Week 1: 10 single lengths

   10 × 1 length easy, resting 30–60 seconds after each. Use a kickboard for any length that leaves you gasping. About 250 m a session.

2. 2

   Week 2: 12 single lengths

   12 × 1 length, resting 30–45 seconds. Focus on breathing out under water so you only need to lift or turn your head to breathe in. About 300 m.

3. 3

   Week 3: lengths in pairs

   8 × 2 lengths (50 m) easy, resting 45–60 seconds. About 400 m.

4. 4

   Week 4: more pairs, plus kick

   10 × 2 lengths, resting 45 seconds, then 4 × 1 length kicking with a board. About 600 m.

5. 5

   Week 5: first 100s

   6 × 4 lengths (100 m) easy to steady, resting 60 seconds. About 600 m, now in bigger blocks.

6. 6

   Week 6: build the 100s

   8 × 4 lengths, resting 45–60 seconds. About 800 m. If this leaves you wrecked, repeat week 5.

7. 7

   Week 7: longer blocks

   4 × 6 lengths (150 m), resting 60 seconds, then 4 × 2 lengths steady. About 800 m.

8. 8

   Week 8: the 20-minute swim

   Two sessions: 3 × 8 lengths (200 m) with 60–90 seconds' rest, then 4 × 2 lengths steady. Third session: swim easy for 20 minutes, resting only when you must, and count your lengths to beat later.

In a 50-metre pool, halve the length counts. If you miss a week, step back one week rather than jumping ahead. After week 8, add a fourth session or lengthen the 20-minute swim towards 30–40 minutes before you start swimming faster.

Can you learn to swim as an adult?

If you can't yet swim a length, start with lessons rather than the plan above. Ask the pools near you whether they run adult batches, whether the batch is for adults only, whether a lifeguard is on deck during lessons and how deep the shallow end is. Good beginner lessons spend the first sessions on breathing out under water, floating, gliding and kicking with a board before full strokes.

Learning takes as long as it takes, and feeling nervous in deep water is common. While you learn, walking or jogging in chest-deep water still counts: the Compendium rates moderate water walking at 4.8 METs, about 144 kcal in 30 minutes at 60 kg. A walking for weight loss routine or cycling for weight loss on the other days keeps your weekly minutes up.

How do you protect your ears and skin in the pool?

Pools are safe for most people if you follow a few basics. The CDC's healthy swimming advice says to stay out of the water if you have diarrhoea, to shower before getting in (a one-minute shower removes most of the dirt, sweat and oils on your body), not to swallow pool water even if it looks clean, and to dry your ears thoroughly after swimming to help prevent swimmer's ear. Cover cuts with waterproof bandages or stay out.

• Ears: dry them with a towel after every swim. Earache, swelling or discharge needs a doctor, not more swimming.
• Skin: shower after the swim and moisturise if your skin feels dry; a rash that keeps coming back is worth showing a doctor.
• Eyes: well-fitting goggles make the plan above far more pleasant.

Should you combine swimming with strength training?

Swimming handles the cardio; two short strength sessions a week handle the muscle. A squat or goblet squat, a hip hinge such as a Romanian deadlift, a row, a push-up or press, and a plank cover the basics, and our gym workout plan for beginners or dumbbell workout at home gives full routines. Put them on non-swim days or lift before an easy swim.

MakeMyFitness is live 1:1 online coaching on video across India, at ₹799 a session at your gym or ₹899 at home, and it suits swimmers who want a coach for the strength and food side of the week; the coaching happens on land, not in the pool. Our coaches are fitness coaches, not doctors, physiotherapists or swimming instructors. Rehab & Recovery is coaching after a clinician has cleared you, and the medical disclaimer sets out what we don't do. To see how the video setup works before you book, read what happens in a first session.