"I Can Swim, But I Get Tired": Fixing Your Swimming Endurance
By Coach Tan Meng Chew (MC), SG Sink Or Swim
Introduction: The Most Common Sentence I Hear at the Pool
"Coach, I can swim. I just get tired."
I have heard this from nervous beginners, from adults who learned as children, from parents who swim with their kids at the condo pool, and from fit runners who cannot understand why two lengths leaves them gasping. Every time, the person is telling the truth. They really can swim. They can move through water without sinking. But somewhere around the second or third length, their arms feel heavy, their breathing turns ragged, their legs sink, and they grab the wall.
The good news is that this is one of the most fixable problems in swimming. Poor endurance in the water is rarely about fitness alone. In most cases it is about efficiency: how much energy you waste for every metre you travel. Fix the waste, and the tiredness mostly fixes itself. Add smart training on top, and you can swim much further than you thought possible.
I write this guide for the SG Sink Or Swim series, which aims to give Singaporeans practical, honest advice about swimming and water safety. Endurance is not just a fitness goal. It is a safety skill. A person who tires quickly in the water is more vulnerable if something goes wrong, whether that is a stronger-than-expected current at the beach, a fall from a boat, or simply a child's accidental splash far from the wall. Being able to keep going matters.
Why Do You Get Tired? Understanding the Real Causes
Before fixing the problem, it helps to understand it. When someone tells me they get tired, I usually find one or more of these causes at work.
1. Poor breathing
This is the number one culprit. Many swimmers hold their breath underwater and then try to inhale and exhale in the split second their face is out of the water. That leaves them short of breath within a few strokes, and it triggers a feeling of panic that has nothing to do with muscle fitness.
Efficient swimmers exhale steadily underwater, through the nose and mouth, so that when their face turns for air, they only need to inhale. If you finish a length breathless, even though your arms feel fine, breathing is almost certainly your problem.
2. A sinking body position
Water is roughly 800 times denser than air. A body that sits at an angle, with the hips and legs dropping, pushes a much larger surface against the water and creates drag. Swimmers with sinking legs have to work harder with every stroke just to overcome the resistance they are creating.
A flat, streamlined body slips through the water. A body that hangs like a diagonal plank forces the swimmer to fight the water all the way.
3. Kicking too hard
Many tired swimmers kick vigorously, with bent knees and a lot of splash. The legs are the biggest muscles in the body and use the most oxygen. A big, frantic kick burns energy quickly and often produces little forward movement.
For distance swimming, the kick should be small, steady and mostly there to keep the body balanced and the hips high.
4. Inefficient arm stroke
Short, choppy strokes, a hand that slips through the water without catching it, crossing the arms over the centre line, or pulling with a straight arm can all waste effort. If your stroke count per length is high, you are probably taking many strokes to cover little distance.
5. Tension
Tense swimmers swim stiffly. Gripping the water, tightening the neck and shoulders and clenching the hands all burn energy. Relaxation is a skill, and in swimming it is a genuine performance advantage.
6. Swimming too fast, too early
Many people start a swim at a pace they cannot hold. They sprint the first length, build up lactic acid and breathlessness, and then spend the rest of the session recovering. Pacing is a skill that most recreational swimmers never learn.
7. Lack of specific fitness
Swimming uses muscles and energy systems differently from running or cycling. A very fit runner can still tire quickly in the water because the specific muscles, such as the lats, shoulders and core, are not conditioned for it, and because breathing is restricted in a way that the runner is not used to.
8. Everyday factors
Poor sleep, skipping meals, dehydration (yes, you can be dehydrated while swimming), heat and stress all reduce stamina. Singapore's warm climate can make this worse, especially in outdoor pools.
First, a Safety Note
Before we go further, an important point. Tiredness in the water can be a warning sign, not just a fitness issue. Stop and rest if you feel any of the following:
Chest pain or tightness
Dizziness or lightheadedness
Unusual breathlessness that does not settle quickly
Numbness or tingling
Nausea
Cramping that does not ease
If you have a heart or lung condition, or any medical concern, speak to your doctor before building up your training. Never push through alarming symptoms.
Also, never practise endurance or breath-holding drills alone, and never practise extreme breath-holding at all. Hypoxic training and underwater breath-hold contests can lead to shallow-water blackout, which can affect even strong swimmers. Swim with a lifeguard on duty or with a buddy, and treat endurance building as a gradual process.
Fix 1: Breathing — The Foundation of Endurance
If I could only fix one thing, it would be this.
Learn to exhale underwater
Practise this at the wall. Hold the edge, put your face in the water and blow out slowly and steadily through your nose and mouth. Then lift your face, take a quick breath and repeat. The goal is a smooth, continuous stream of bubbles, not a held breath followed by a burst.
A useful image is to imagine you are blowing out a long candle flame underwater. The exhale should last the entire time your face is in the water.
Breathe rhythmically
In freestyle, most people breathe every two or three strokes. Every three strokes, known as bilateral breathing, balances the stroke on both sides and helps with relaxation, though it may feel too demanding at first. Every two strokes is fine if you are comfortable. What matters is that you breathe regularly. Holding your breath for several strokes in a row, and then gasping, is a classic cause of fatigue.
Keep your head low
When you turn to breathe, rotate your head with your body, keeping one goggle in the water. Lifting the head forward pushes the hips down and wastes energy. Think "roll, breathe, roll back."
Practise with a snorkel
A front-mounted swimming snorkel lets you focus on body position and stroke without worrying about breathing. It is a useful tool, though a coach can advise whether it suits you.
Drill: Breath-count practice
Swim a length breathing every two strokes, then every three, then every four, then back down. Notice how you feel. The aim is not to hold your breath for longer, but to practise staying relaxed and rhythmic.
Fix 2: Body Position and Streamlining
Press the chest, lift the hips
Many swimmers sink their legs because they look forward. Instead, point your eyes at the pool bottom, with the water level around the top of your head. Imagine that you are pressing your chest gently down into the water, which raises your hips and legs.
Engage the core
A stable core keeps the body aligned. You do not need dramatic abdominal strength, just a gentle tightening that stops the hips from swaying and sagging.
Drill: Kick on your side
Lie on your side with one arm stretched out in front and the other resting by your hip, with your head resting on your outstretched arm and your face looking sideways. Kick gently and breathe naturally. This teaches balance and body rotation, which are central to efficient freestyle.
Drill: Superman glide
Push off the wall in a streamlined position and glide as far as you can, with your arms stretched out in front, head down and body flat. Notice how far you travel with no effort. This shows what a streamlined body can do. The further you glide, the less energy you will need for every stroke.
Fix 3: Make Your Kick Work for You
Small, quick, from the hips
For distance, the kick should come from the hips and not the knees, with relaxed ankles and a narrow, steady beat. Think of "flutter" and not "thrash". A good flutter kick has feet that barely break the surface.
Relax the ankles
Stiff, flexed ankles act like brakes. Flexible ankles, with toes loosely pointed, create propulsion. If you struggle with ankle flexibility, kicking with fins during drills can help develop it over time.
Do not kick harder when tired
When fatigue sets in, many swimmers kick harder to compensate. This usually backfires. Keep the kick light and let a controlled stroke do the work.
Drill: Kick with a board
Use a kickboard for a few lengths and aim for a gentle, consistent kick that moves you forward without splashing. Count how long it takes you to cover a length, and notice improvement over weeks.
Fix 4: Refine Your Stroke
Reach long, not short
A longer stroke covers more distance with each pull. Extend your arm forward, rotating the shoulder and hip together, and enter the water ahead of your head.
Catch the water
After your hand enters, bend the elbow slightly and press the forearm and palm backward. This "early vertical forearm" position, as coaches call it, engages the bigger muscles in the back and shoulder. A straight-arm pull relies on small muscles and tires quickly.
Rotate your body
Swimming flat on the stomach limits reach and strains the shoulders. Rolling the body from side to side, driven by the hips, lengthens each stroke and makes breathing easier.
Count your strokes
Count how many strokes it takes to cross a length. Over a few sessions, try to reduce that number by a stroke or two without slowing down. This is one of the best indicators of improving efficiency. A lower stroke count at the same pace means you are getting more from each pull.
Drill: Catch-up freestyle
Swim freestyle, but wait for one hand to touch the other in front before starting the next stroke. This promotes a long reach and a patient stroke.
Drill: Fingertip drag
As your arm recovers over the water, drag your fingertips lightly along the surface. This encourages a high elbow and a relaxed recovery.
Fix 5: Learn to Relax
Tension shows up everywhere
Check yourself mid-length. Are your shoulders hunched? Is your jaw clenched? Are you gripping the water with stiff fingers? Practise releasing tension on purpose. Soft hands, a relaxed neck and loose shoulders make a visible difference.
Slow down to speed up
Most tired swimmers try too hard. Ironically, slowing down, extending your stroke and breathing calmly often produces an equal or better pace for much less effort.
Use the wall to reset
If you feel panicky, stop at the wall, take a few slow breaths and begin again. There is no shame in this. In fact, interval training deliberately builds rest into a session.
Fix 6: Pacing — Swim Smarter, Not Harder
Start slower than you think you should
Choose a pace at which you could hold a conversation, if only in short phrases. If you are gasping by the end of the first length, you started too fast.
Use the rate-of-effort scale
Rate effort on a scale of one to ten. For endurance building, aim for about four to six. At this effort, you are working but not struggling.
Use intervals
Instead of trying to swim non-stop, break the distance into manageable chunks with short rests. For example, 8 × 25 metres with 20 seconds' rest is a far better starting point than a failed attempt at 200 non-stop.
Negative splitting
This means swimming the second half of a distance slightly faster than the first. It teaches patience and control.
Building Endurance: A Progressive Plan
Below is a simple, flexible plan for a swimmer who can swim a few lengths of freestyle but tires quickly. Adjust distances to your level, and use a coach's guidance if possible. These are suggestions, not a medical prescription.
Weeks 1–2: Foundations
Aim for two to three sessions per week of about 20 to 30 minutes.
Warm-up: 4 × 25 m easy, any stroke
Breathing drill: 4 × 25 m focusing on bubble exhale and regular breathing
Kick: 4 × 25 m with a kickboard, small and steady
Main set: 6 × 25 m freestyle, 20–30 seconds' rest between lengths
Cool-down: 2 × 25 m easy
The goal here is quality and relaxation, not distance.
Weeks 3–4: Extending the swim
Warm-up: 4 × 25 m easy
Technique: 4 × 25 m catch-up freestyle
Main set: 4 × 50 m freestyle, 20–30 seconds' rest
Cool-down: 2 × 25 m easy
Try to keep the same stroke count on each 50.
Weeks 5–6: Building continuous swimming
Warm-up: 100 m easy
Technique: 4 × 25 m side kick or superman glides
Main set: 3 × 100 m freestyle, 30 seconds' rest
Cool-down: 100 m easy
Focus on rhythm and pacing, not speed.
Weeks 7–8: Longer sets
Warm-up: 150 m easy
Main set: 2 × 200 m freestyle at a steady pace, 45 seconds' rest
Technique: 4 × 25 m drills
Cool-down: 100 m easy
Beyond eight weeks
From here, gradually lengthen the continuous swims, for example 300 m, 400 m and eventually 500 m or more, while keeping technique sound. Add one session per week that emphasises a steady, longer swim and another that includes some faster intervals. Always build gradually, with roughly ten per cent increases rather than sudden jumps.
Training Tools That Help
You do not need much equipment, but a few items can speed up progress.
Pull buoy. Held between the thighs, it lifts the legs and allows you to focus on the arm stroke. Use it sparingly, since it can mask a poor body position.
Kickboard. Useful for building a steady kick, though it can strain the shoulders if overused.
Fins. Short training fins help with ankle flexibility and kicking strength, and encourage a better body position.
Swim snorkel. Takes breathing out of the equation so you can work on body position and stroke.
Tempo trainer or a pace clock. Helps with rhythm and pacing.
Goggles that fit. Leaking, fogging goggles are an underrated source of frustration. A good fit makes a surprising difference.
Dry-Land Support
Swimming is the best training for swimming, but a little out-of-water work can help.
Core exercises: planks and dead bugs for body position
Shoulder stability: band exercises for the rotator cuff
Mobility: stretches for shoulders, chest and ankles
Light cardio: cycling or jogging for general aerobic fitness
If you have joint problems or injuries, get guidance first.
Fuelling and Recovery
Eat sensibly
A light meal or snack one to two hours before swimming usually works well. Avoid a heavy meal immediately beforehand. Afterwards, eat something with carbohydrates and protein to support recovery.
Drink water
You sweat in the pool, particularly in Singapore's warm weather, even if you do not notice it. Keep a bottle at the poolside.
Sleep
Recovery happens when you rest. Ongoing tiredness may reflect a lack of sleep, not poor fitness.
Listen to your body
Aching muscles are normal. Sharp joint pain, especially in the shoulders, is not. If something hurts persistently, rest and seek professional advice.
Endurance for Different Swimmers
Adults returning to swimming
Many adults learned as children and have not swum since. Be patient. Technique often comes back faster than fitness, and it is better to begin with short, easy sets. Consider a few lessons to correct old habits.
Parents who swim with their children
Short bursts of play do not build much endurance, but they do build comfort. If you want to improve for your own sake, try a short session of focused lengths while a partner or another adult supervises the children. Never leave a child unsupervised while you swim laps.
Runners and cyclists
Fitness in other sports helps with general recovery and heart-lung capacity, but swimming is technique-heavy. Do not be discouraged if your first sessions humble you. This is extremely common.
Open water and triathlon
Open water adds waves, currents, sighting and lack of walls. Build endurance in the pool first, then practise open water with a group and in a supervised setting.
Older swimmers
Swimming is wonderful for lifelong fitness because it is gentle on the joints. Go slowly, warm up well and check with your doctor if you have health conditions.
Common Mistakes When Building Endurance
Doing too much too soon. Overtraining leads to fatigue and injury.
Ignoring technique. Swimming more with bad technique just practises bad technique.
Never resting. Recovery is when you get stronger.
Comparing yourself to others. Everyone progresses differently.
Skipping the warm-up. Cold muscles tire faster.
Holding the breath. This is worth repeating.
Training alone in poor conditions. Always choose a supervised pool when possible.
Expecting overnight results. Endurance builds over weeks and months.
Tracking Your Progress
Keep a simple log. Note the date, distance, how you felt and any observations. Useful measures include:
The longest distance you can swim continuously with good form
Your stroke count per length
Time for a standard distance, such as 100 m
How quickly your breathing settles after a hard set
Your perceived effort at a given pace
Progress is not always linear. Some weeks will feel harder than others, and that is normal.
The SG Sink Or Swim Perspective
At SG Sink Or Swim, we treat endurance as part of water safety, not only as a fitness goal. The aim is not to turn every swimmer into a competitor. It is to help each person gain enough strength, efficiency and calm to handle themselves in the water.
That is why I stress technique and breathing before distance. A swimmer who is efficient and relaxed can keep going far longer than one who is simply strong but wasteful. And a swimmer who knows how to float, rest and breathe calmly has a real safety advantage, because floating on the back to catch your breath is one of the best survival skills there is.
If you are struggling with tiredness in the water and want a coach to look at your stroke, you are welcome to contact SG Sink Or Swim. A trained eye can spot in a few minutes what might take you months to figure out alone.
Frequently Asked Questions
How long does it take to build swimming endurance?
It varies. Many people notice meaningful improvements within four to eight weeks of consistent practice, especially if they correct breathing and technique. Larger goals, such as swimming 1,000 metres or more continuously, can take several months.
Why do I get tired after only one or two lengths?
Most often it is breathing, body position or pacing. Fitness matters, but these three are usually the main culprits.
Is it better to swim more often or for longer?
For most people, more frequent shorter sessions beat occasional long ones, particularly when technique is still developing. Two to four sessions a week is a sensible goal for many swimmers.
Should I use a pull buoy all the time?
No. It is a useful tool but can hide problems with leg position. Use it as part of a varied session.
Does swimming faster build endurance?
Some faster intervals help, but most endurance work should be done at a comfortable, controlled effort.
Why do my legs sink when I get tired?
Fatigue often reduces core stability and kick, and tired swimmers tend to lift their heads, which drops the hips. Focus on body position and keep your head low.
Can I build endurance if I only swim at my condo pool?
Yes, as long as the pool allows continuous lengths and is not too crowded. A short pool means more turns, which can interrupt rhythm, but it is still useful. Use interval sets if lengths are very short.
I feel dizzy or unwell when I swim hard. What should I do?
Stop, rest and get out of the water if needed. If it keeps happening, see a doctor before continuing.
Conclusion: Efficiency First, Then Endurance
"I can swim, but I get tired" is not a life sentence. It is a puzzle with a solution, and the solution is usually a combination of:
Breathing properly, with a steady exhale underwater
Swimming flat, with a streamlined body position
Kicking gently from the hips
Refining your stroke for length and efficiency
Staying relaxed
Pacing yourself with intervals and sensible effort
Building gradually, with a consistent plan
Looking after your body with food, water, sleep and rest
Do these things patiently, and you will find that the same pool that left you gasping a month ago becomes a place where you can swim comfortably, lap after lap.
Most of all, remember that you are not just training for a number on a lap counter. You are building a skill that can keep you safe, healthy and confident in the water for life. That is what SG Sink Or Swim is all about.
— Coach Tan Meng Chew (MC), SG Sink Or Swim
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