Swimming for weight loss: swimming and water aerobics for a heavier body

Is swimming good for weight loss? An honest answer

Yes, swimming is good for weight loss, but mostly because it lets you keep moving week after week, not because each session burns a huge amount. Food still does most of the work, and the pool is a strong partner to it.

In water your body floats. That takes load off your knees, hips, feet and back, which is the big gift of the pool for anyone who finds walking on land painful.

The flip side is that floating also makes some movements cheaper in energy. At a gentle pace, a heavier swimmer may use less energy per minute than the same person walking briskly uphill. What you gain is time: many people can stay active in the pool for 30 minutes or more while a land walk would stop after ten.

What the numbers really mean

Researchers measure effort in METs, a way of comparing an activity with sitting still. The latest Adult Compendium of Physical Activities gives each water activity its own value, from slow water walking to fast front crawl.

Turned into kilocalories, the table below shows typical 30-minute sessions for three body weights. The numbers include the energy you would use resting anyway, and they are rough estimates, not a target to chase.

The values come from people of average build, so treat them as a rough guide. Extra body fat floats, so a larger swimmer may use a bit less than the table suggests at the same pace.

For your own weight and minutes, try our calories burned calculator. Use it out of interest, not to earn food: a pastry after the pool can easily cancel a whole session.

Why water exercise suits a larger body

Water exercise suits a larger body because the water carries part of your weight, cools you while you work and lets you control the effort with every movement. You can work your heart and lungs without the pounding that comes with each step on a pavement.

• Buoyancy. The deeper you stand, the more of your weight the water holds up. At chest depth your knees and feet carry only a fraction of their usual load.
• Resistance in every direction. Water pushes back against your arms and legs, so you build some strength while you move. Faster movements meet more resistance; slower ones meet less.
• Staying cool. Many heavier people overheat quickly on land. In a pool the water draws heat away, which often makes longer sessions more pleasant.
• Less fear of falling. Losing your balance in water is slow and soft. That gives confidence to people who feel unsteady on their feet.

If sore knees are your main concern, our guide to exercise with bad knees compares the pool with the bike and other options.

What happens to your heart in water

When you stand in water up to your chest or neck, the water pressure pushes blood from your legs towards your chest. Your heart then fills with more blood at each beat.

For a healthy heart this is no problem, and it may be part of why pool exercise often feels easier than its effort suggests. In people who had a large heart attack in the past, small studies found that standing in neck-deep water could raise the pressure in the blood vessels of the lungs for a while.

Supervised water training is still used in stable heart failure, and reviews show gains in fitness similar to land training. The key word is supervised: if your heart is weak, the right depth and effort need to be set by your cardiologist or a cardiac rehab team.

Talk to your doctor first if…

Talk to your doctor first before you start any pool plan. Ask in particular if one of these applies to you:

• you have heart failure, angina, a past heart attack, a heart rhythm problem or very high blood pressure;
• you have asthma or COPD that flares up with exercise or in cool air;
• you use insulin or tablets that can cause low blood sugar, because a hypo in water is more dangerous than on land;
• you have numb feet, foot wounds or ulcers, or skin problems in skin folds;
• you have epilepsy or have fainted in the past;
• you have recently had surgery, an open wound or a skin infection.

For most of these, the answer is not “no pool” but “start this way”. Write your questions down beforehand with our doctor visit checklist.

Leave the water and get help at once if you feel chest pain or pressure, severe breathlessness, dizziness, or a heart that races or beats irregularly. Tell the lifeguard straight away.

Water aerobics for weight loss: what the trials show

Water aerobics does help with weight loss, according to the latest pooled research, although the effect on its own is modest. Classes lowered body weight and waist size in people with overweight or obesity, even without any diet change.

A systematic review in BMJ Open combined 10 randomised trials with 286 participants. The classes included classic water aerobics, aqua zumba, water yoga and aqua jogging, mostly three times a week for about an hour, over 6 to 12 weeks.

Compared with people who did not take part, the class groups lost about 2.7 kg of body weight and about 2.75 cm from their waist. The authors rated the certainty of these two results as moderate, which is fairly good for exercise research.

Who seemed to gain most

The effects were larger in women and in people aged around 45 and over. That is good news for anyone who thought exercise had passed them by.

Other measures, such as percentage body fat and muscle mass, did not change clearly. The trials were short and small, so a longer programme may well show more.

What this means for you

In these trials nobody changed their food. Add a gentle eating plan and the results usually grow, because most weight loss comes from eating a little less, every day.

A waist that shrinks by a few centimetres is worth celebrating, even if the scale moves slowly. Deep belly fat is linked with heart and blood sugar problems; our page on belly fat explains what helps reduce it.

The same steady mix of moving more and eating a little less also helps the liver. If your doctor has mentioned fat in your liver, see our page on fatty liver and weight loss.

Swimming vs walking for weight loss: which should you choose?

For most people the best answer is both: walking for everyday movement and the pool for longer, joint-friendly sessions. The studies that compare them point in different directions, so do not choose on the research alone.

An old American trial is often quoted. Young women with mild to moderate obesity exercised daily for about six months, building up to an hour, without changing their diet; the walkers lost about 10 % of their weight and the cyclists 12 %, while the swimmers lost none.

That study was small and is now decades old, so it should not put you off on its own. A later Australian trial in 116 inactive women aged 50 to 70 found the opposite.

In that trial, women swam or walked three times a week at moderate effort. After a year, the swimmers weighed about 1.1 kg less than the walkers, and after six months their waists were slightly smaller too.

Water walking vs land walking

In a trial in older adults, water walking and land walking gave similar gains in fitness after 24 weeks, when people worked at the same relative effort. Both groups built up to 150 minutes a week.

So the pool is not a second-class choice. It is a real option, especially on days when your joints protest.

How to combine the two

Walking is free, close to home and possible every day. A pool session needs travel, a ticket and a changing room, so most people go two or three times a week.

A good mix is short daily walks plus two or three pool sessions. Our page on walking for weight loss has the land side of the plan, and cardio for weight loss ranks all types of cardio for a heavier body. On days you cannot get to a pool, low impact cardio at home is a good stand-in.

If you cannot swim (well): aqua jogging, shallow-water exercise and lessons for adults

If you cannot swim, or not well, you can still get almost all the benefits of the pool by staying where you can stand or by using a float belt in deep water. Many people in aqua classes never swim a single length.

Shallow-water exercise

Stay in water between your waist and your chest. Walk forwards, backwards and sideways, lift your knees, swing your arms and push the water with open hands for more resistance.

A simple circuit is two minutes of walking, then one minute of a single move, such as knee lifts or arm sweeps, and repeat. Rest at the side whenever you need to.

Aqua jogging

Aqua jogging, also called deep-water running, means running movements in water too deep to stand in, while a float belt keeps your head above the surface. Your feet never hit the floor, so there is no impact at all.

A review of deep-water running studies found fitness gains similar to those from training on land. A study in women with large breasts found less breast discomfort than on a treadmill, which many women will find welcome.

Start in the lane next to the edge, ask the lifeguard to check your belt, and keep the first sessions short. Aqua jogging is harder than it looks.

Swimming lessons for adults

It is never too late to learn. Many pools run adult lessons in small groups, often in the evening and sometimes in a separate lesson pool.

A good teacher starts with breathing out under water and floating, not with lengths. Floating comes easier to many larger bodies, because body fat floats well.

Water safety for non-swimmers

• Choose a pool with a lifeguard, and avoid lakes and the sea until you swim confidently.
• Stay at a depth where you can stand unless you wear a float belt and a teacher or lifeguard knows.
• Do not go in alone, and tell staff that you are a beginner.
• Watch for slopes in the pool floor, where the shallow end suddenly becomes deep.

How long and how often to swim to lose weight

Aim to build up to about 150 minutes of moderate activity a week across all your movement, with two or three pool sessions of 20 to 45 minutes as part of that. More minutes help with weight loss, but only once your body is used to them.

The World Health Organization advises adults to do 150 to 300 minutes of moderate activity a week, or half that time at a vigorous effort. Pool minutes count fully, just like walking.

The aqua trials above used about three hours a week. That is a good long-term goal, not a starting point.

How hard should it feel? The talk test

You should be able to talk in short sentences while you move. If you can sing, go a little faster; if you can only say a word or two, slow down.

The talk test is a simple, reliable guide to moderate effort, and it works without any device. If you like numbers, our heart rate zones calculator gives a range, but in water the talk test is often the easier guide.

Easy pace is enough

You do not need to swim fast or count lengths. Slow, steady work that you can keep up for 20 minutes beats a hard sprint you dread.

Once 30 minutes feels comfortable, you can add short faster bits: one minute brisker, two minutes easy, a few times. That is plenty of variety for most people.

A 12-week pool plan for beginners

This plan takes you from two 15-minute sessions to three 30-minute sessions a week. Talk to your doctor first, and start only when you have the go-ahead.

Each session begins with 3 to 5 minutes of slow water walking to warm up and ends the same way to cool down. These minutes are included in the times below. Our page on warm-up and stretching has gentle moves for afterwards.

How to use the plan

The time grows by roughly 10 % a week at most, and only one thing changes at once: either the minutes or the number of sessions. Weeks 4 and 8 step back on purpose, so your body can catch up.

If an aqua class lasts 45 minutes, you can still join from week 3. Work gently, rest at the side when you need to, and let the plan’s minutes be your active time.

Repeat any week that felt too hard. Mild muscle tiredness the next day is normal; pain in a joint, chest symptoms or exhaustion that lasts are reasons to step back and check with your doctor.

After week 12

By week 12 you are in the water for about 90 minutes a week. With daily walks on land, you reach the 150-minute guideline.

From here you can add a fourth session, lengthen one session, or keep this routine for months. Add one or two short strength sessions a week too; our guide to strength training explains why muscle helps while you lose weight.

For land-based moves on non-pool days, the free workout videos start at Level Start, mostly seated and without jumping.

Does swimming make you hungry?

Sometimes, yes, and cool water may be part of the reason. Plan your next meal so you are not tempted by the vending machine on the way out.

In a small study, 11 young men cycled in water for 45 minutes, once in cool water and once in warm water. They used the same energy both times, but after the cool session they ate about 40 % more from a buffet than after the warm session or after resting.

That was one small study, so it is not proof for everyone. Wider research shows that a single exercise session usually does not raise appetite much on average, but people differ a lot.

Simple ways to stay on track

• Eat a normal meal one to three hours before you swim, so you do not arrive hungry. Our page on the pre-workout meal has ideas.
• Have your next meal ready, with protein and vegetables or fruit, for when you get home.
• Bring water and a piece of fruit in your bag instead of buying a snack at the pool café.
• Warm up after the pool with a hot shower and dry clothes; feeling cold can make you crave food.
• Check for a few weeks what you eat on pool days. If the scale stays still, our guide to calorie counting helps you find the extras.

Feeling at ease in the pool: changing rooms, swimwear, quiet sessions and comments

Feeling nervous about being seen in swimwear is very common, and it is the main reason many larger people never try the pool. A few practical steps make the first visits much easier.

Before you go

• Visit or call first. Ask about quiet hours, adult-only or women-only sessions, and whether there are steps or a hoist into the water.
• Ask about changing cubicles and family or accessible changing rooms, which are often more private.
• Bring a friend for the first few times, or join a beginner class where everyone is new.

Swimwear that works

Choose swimwear for comfort and confidence, not for how other people might look. Many shops sell longer swim shorts, swim leggings, tankinis and swim dresses in a wide range of sizes.

A towelling robe or a large towel covers the walk from the changing room to the pool. Pool shoes give grip on wet tiles.

Getting in and out safely

Use the steps or a ramp rather than the ladder if climbing is hard. Hold the rail with both hands and take your time.

Ask the staff if you need help; many pools have a lift or hoist and are used to helping. That is what it is there for.

If someone makes a comment

Most people at the pool are busy with their own lengths. If someone does say something hurtful, you have every right to be there, and you can tell the staff.

Comments about weight are never your fault. Our page on weight stigma explains how it affects people and what you can do about it.

Free help to lose weight with swimming and walking

Obesity Foundation helps people lose weight and feel better with good food, suitable exercise and walking. Swimming fits right in, and all of our help is free.

• A free eating plan with filling everyday meals, so your pool days and your food work together. Request your free eating plan.
• Free workout videos in three levels, Start, Build and Strong, for the days you are not in the pool. Get the free workout videos.
• A free video meeting (in English) to talk through how to fit swimming and walking into your week. Book a free video meeting.
• A free Club account to log your pool sessions, walks and progress over time. Join the Obesity Foundation Club.

Aim for steady progress: our page on safe weight loss explains a realistic pace. Your first pool session can be 15 minutes of walking in the shallow end, once your doctor agrees.