Swimming endurance: how to stop getting tired
By Coach Tan Meng Chew (MC), SG Sink Or Swim
One of the most common things I hear at the pool is a breathless, slightly embarrassed sentence from a learner hanging onto the wall: "I'm so tired. I only did one length."
If that sounds familiar, take comfort. It is one of the most common experiences in swimming, and it happens to people of every age and fitness level. I've coached runners who can cover ten kilometres but gasp after twenty-five metres in the water. I've coached young children with endless energy on land who tire after a few kicks. I've coached adults who are physically strong but exhausted within minutes of swimming.
The reason is simple: swimming is not like other forms of exercise. Water is about 800 times denser than air, you're horizontal, your breathing is restricted, and your body has to work in an unfamiliar way. Fitness helps, but technique helps more.
In this article I'll explain why swimmers get tired so quickly, the real causes (most of which are not about fitness), and a practical set of fixes, from technique and breathing to pacing, training habits and mindset. I'll also share how I approach endurance with learners at SG Sink Or Swim.
First, Why Does Swimming Feel So Tiring?
Let me start with the good news: if you tire quickly in the water, it usually doesn't mean you're unfit or not "built for swimming". More often, it means your body is spending energy in the wrong places.
Here are the main reasons swimming feels so tiring, especially for beginners.
Water resistance is huge. Moving through water requires far more effort than moving through air. Every bit of drag, from a dropped hip to a wide kick, slows you down and burns energy.
You're fighting the water instead of working with it. Beginners tend to thrash, push and pull hard. Skilled swimmers glide, relax and let the water support them.
Breathing is restricted. On land, you breathe whenever you want. In swimming, you must breathe at specific moments. If you hold your breath or breathe poorly, carbon dioxide builds up and you feel breathless quickly.
Tension wastes energy. Tight shoulders, clenched hands, a stiff neck and a tense jaw all use energy without helping you move.
Poor body position creates drag. If your legs sink or your head lifts too high, your body becomes like a wall pushing through the water.
Your muscles are working in unfamiliar ways. Even fit people use different muscle groups and movement patterns in swimming, so they tire faster at first.
Fear and stress raise your heart rate. If you feel anxious, your heart races, your breathing becomes shallow and you tire more quickly.
Almost all of these can be improved. And here's the key insight I share with every learner: endurance in swimming is mostly about efficiency, not just fitness.
The Efficiency Mindset: Swim Smarter, Not Harder
Think about two people crossing a river. One thrashes and splashes, using all their strength to fight the current. The other moves smoothly, using small, controlled strokes. The second person arrives less tired, even if they're less powerful.
Swimming is the same. The most efficient swimmers aren't always the strongest. They're the ones who:
Reduce drag by staying flat and streamlined
Use their energy only where it counts
Stay relaxed
Breathe rhythmically
Glide between strokes
If you take only one idea from this article, let it be this: every unnecessary movement and every bit of tension is energy you can't spare. The first step to better endurance is learning where you're wasting energy.
The Seven Big Causes of Fatigue (and How to Fix Each One)
Let's go through the main culprits one by one.
1. Poor Breathing
Breathing is the number one reason beginners get tired. Many learners hold their breath while their face is in the water, then gasp when they turn to breathe. This creates a cycle of breath-holding and panic that exhausts you quickly.
What goes wrong:
Holding the breath under water
Breathing in and out only when the face is out of the water
Lifting the head too high to breathe
Shallow, rapid breathing
Not breathing out fully, so carbon dioxide builds up
How to fix it:
Exhale continuously under water. As soon as your face goes in, start blowing out through your nose and mouth, slowly and steadily. When you turn to breathe, you only need to inhale quickly.
Turn, don't lift. In freestyle, rotate your head to the side with your body, keeping one goggle in the water. Lifting your head forward makes your hips sink.
Breathe rhythmically. Find a pattern that works, such as every two or three strokes, and stick with it. Random breathing disturbs your rhythm.
Practise bubbles. Standing in shallow water, practise blowing out slowly and steadily for 5 to 10 seconds. It sounds simple, but it's the foundation of endurance.
Stay calm. Relaxed breathing is far more efficient than panicked breathing.
Many learners find that when their breathing improves, their endurance doubles almost overnight.
2. Sinking Legs and a Poor Body Position
If your hips and legs drop low in the water, your body acts like a brake. You then have to kick harder and pull harder just to keep moving, which tires you fast.
What goes wrong:
Lifting the head to look forward
Tight hips and lower back
Weak or inefficient kick
Not engaging the core
How to fix it:
Look down, not forward. In freestyle, keep your head neutral, with your eyes looking at the pool floor, slightly forward. Lifting your head pushes your hips down.
"Press the chest" gently. Imagine leaning slightly on your chest, which helps raise your hips.
Engage your core lightly. A little tension in the stomach helps keep the body in line, but don't clench.
Practise streamlined glides. Pushing off the wall and gliding in a long, flat position teaches your body what good alignment feels like.
Use a kickboard and fins carefully (if your coach recommends them) to build awareness of position.
3. Over-Kicking
Many beginners kick too hard and too deep, often with bent knees. The legs are the biggest muscles in the body, so kicking hard burns a lot of energy and raises your heart rate quickly.
What goes wrong:
Large, bicycle-like kicks from the knees
Kicking too hard to "stay up"
Stiff, flexed ankles
How to fix it:
Kick from the hips, with relaxed, floppy ankles and a small, quick movement.
Keep kicks small and close to the surface. A narrow, tight kick is more efficient.
Use the kick for balance, not speed. In distance swimming, the legs mainly support your body position.
Practise gentle, steady kicking rather than powerful bursts.
Work on ankle flexibility. Gentle stretching on land can help, since tight ankles produce a poor kick.
4. Pulling Too Hard and Rushing the Stroke
Another common mistake is windmilling the arms quickly, with little effect. Fast, short, frantic strokes use a lot of energy and produce little forward movement.
What goes wrong:
Short, choppy strokes
Pulling the water with a straight, stiff arm
No glide between strokes
Crossing the arms over the centre line
How to fix it:
Lengthen your stroke. Reach forward, slide your hand in, and extend before you pull.
Let one arm "catch up" with a pause. Catch-up drills, where one arm waits for the other, teach you to glide and extend.
Use a high elbow during the pull, with your forearm and hand facing back, so you push more water and less energy is wasted.
Count your strokes per length. Try to reduce the count gradually. Fewer strokes with the same effort usually means better efficiency.
Relax your hands. Keep fingers slightly apart and loose, not clenched.
5. Tension and Stiffness
Tension is a silent energy thief. Many learners grip the water, hunch their shoulders, tighten their neck, and clamp their jaw, all without realising it.
What goes wrong:
Tight shoulders and neck
Clenched fists
Rigid body
Anxiety about getting tired
How to fix it:
Scan your body. At the wall, quickly check: are your shoulders relaxed? Is your jaw loose? Are your hands soft?
Exhale to relax. A long, slow exhale tends to release tension.
Swim slower. Slowing down gives you time to relax. You can build speed later.
Do relaxed drills. Easy floating, gentle gliding and back float all train your body to relax in water.
Smile, gently. It sounds silly, but it genuinely helps reduce facial tension.
6. Swimming Too Fast, Too Soon
Many adults and children start each swim at maximum speed, then crash after a few metres. In swimming, pacing is critical.
What goes wrong:
Sprinting the first length
Not resting properly
Pushing too hard when tired, which breaks technique
How to fix it:
Start slower than you think you need to. You should be able to talk in short sentences after a length at an easy pace.
Aim for a steady rhythm. Consistency beats bursts of speed.
Use the wall as a rest point. Rest for 15 to 30 seconds between lengths when you're building endurance.
Use the "conversational pace" rule. If you can't breathe comfortably, you're going too fast.
Increase distance before speed. Build up the number of lengths first, then work on pace.
7. Low Fitness, Poor Recovery or Lifestyle Factors
Technique matters most, but general fitness, rest and daily habits do play a role.
Possible factors:
Not enough sleep
Skipping meals or poor hydration
Training too much, too soon
Not enough recovery between sessions
General stress
How to help:
Eat sensibly before swimming. A light meal or snack an hour or two beforehand works for many people. Avoid heavy meals right before getting in the water.
Stay hydrated. It's easy to forget to drink when you're in water, but you still sweat.
Rest properly. Muscles adapt during recovery, not just during training.
Add general fitness gradually. Walking, cycling, light strength work and stretching support swimming. Check with your doctor first if you have any health concerns or are returning to exercise after a long break.
A Quick Technique Checklist for Endurance
Here's a simple checklist you can use at the pool. After each length, ask yourself:
Am I breathing out under water?
Is my head neutral, looking down?
Are my hips near the surface?
Is my kick small and relaxed?
Am I gliding between strokes?
Are my shoulders and hands relaxed?
Am I swimming at a pace I can sustain?
If you can say yes to most of these, you're already saving energy. If not, pick one to work on each session. Trying to fix everything at once usually leads to frustration.
How to Build Endurance Step by Step
Once your technique is more efficient, you can start building endurance deliberately. Here's the approach I recommend.
Step 1: Start With Short Distances and Rests
If you can only swim 25 metres before tiring, that's fine. Swim 25 metres, rest at the wall for 20 to 30 seconds, then repeat. Do this several times. This is called interval training, and it allows you to accumulate more total distance without exhausting yourself.
For example, a beginner session might be:
6 × 25 metres, resting 30 seconds between each
Step 2: Gradually Increase Distance
Over several weeks, slowly lengthen your swims. Perhaps move to 4 × 50 metres with a bit more rest, then gradually shorten the rest. Aim for small increases, not big jumps. As a rough guide, many coaches suggest increasing your total volume by no more than about 10 percent per week, but listen to your body.
Step 3: Reduce Rest Gradually
As you improve, decrease the rest time. If you were resting 30 seconds, try 20, then 15, then 10. Eventually you may be able to swim longer continuous distances.
Step 4: Add Continuous Swims
Once you feel comfortable, try a longer continuous swim at an easy pace, for instance 100 metres, then 200, then more. Keep technique as your priority. If your form falls apart, take a rest and start again.
Step 5: Mix Strokes
If you know more than one stroke, swapping strokes can give tired muscles a rest. For example, swim freestyle for two lengths, then backstroke or breaststroke for one. This lets you stay in the water longer while giving certain muscles a break.
Step 6: Use Drills
Drills isolate parts of the stroke and improve efficiency. Examples include:
Kick with a board: builds leg strength and rhythm
Single-arm drill: helps with balance and rotation
Catch-up drill: teaches glide and extension
Side-kick drill: improves body position and breathing
Drills may feel slow, but they pay off in endurance.
Step 7: Be Consistent
The best endurance builder is regular practice. Swimming two or three times a week, even for 30 to 45 minutes, is much more effective than one long session every few weeks.
A Sample Endurance-Building Session
Here's an example for an adult beginner or improving swimmer. Adjust the numbers to suit your level.
Warm-up (5 to 10 minutes):
Easy swimming or walking in the water
A few relaxed floats and glides
Technique set (10 minutes):
4 × 25 metres kick with a board, 20 seconds rest
4 × 25 metres focusing on one technique point (such as breathing or head position), 20 seconds rest
Main set (10 to 15 minutes):
4 × 50 metres at an easy, steady pace, 30 seconds rest
Cool-down (5 minutes):
Easy swimming, backstroke or floating
Total time is about 30 to 40 minutes. For children, sessions would be shorter and more play-based.
Endurance for Different Learners
Different people face different challenges. Here are some tailored thoughts.
Children
Children often tire quickly because their bodies are smaller and their technique is still developing. They also lose heat faster in water, which can make them tired and cold. For children, I focus on:
Short, fun activities with frequent rests
Games that encourage kicking, floating and breathing
Gradual increases in distance over time
Never pushing a tired or cold child to continue
If you're curious about water temperature and why children get cold, I've covered that in another article.
Adults
Adults often tire because of tension, fear and a lack of body awareness in water. Many are fit on land but unused to the specific demands of swimming. For adults, I focus on:
Breathing and relaxation first
Technique and body position
Gradual progression in distance
Patience with the learning curve
Older Learners
Older learners can build excellent endurance, but may need more recovery time and a gentler build-up. If you're older or have any health conditions, check with your doctor before beginning a new exercise programme. Focus on steady, comfortable swimming, and don't compare yourself with others.
Fitness-Focused Swimmers
If you already swim laps and want to improve endurance, focus on efficiency, steady pacing, breathing patterns and structured interval sets. Even experienced swimmers benefit from regular technique checks.
The Mental Side of Endurance
Endurance isn't only physical. Your mind plays a big role.
Fear and fatigue are connected. If you're afraid of being too tired to reach the wall, your body tenses and you tire faster. Knowing you can stop and rest at any time helps.
Break the distance into chunks. Instead of thinking "I need to swim 200 metres," think "just reach the next flag" or "just finish this length."
Focus on one thing at a time. Concentrate on your breathing, your kick or your glide, rather than on how tired you feel.
Be kind to yourself. Everyone gets tired. It's a sign you're challenging yourself, not a sign you're failing.
Celebrate small wins. One extra length, one more smooth breath, one calmer swim: these are all progress.
What To Do When You Feel Tired in the Water
Even with good technique, you'll sometimes get tired. Knowing what to do in those moments matters, both for confidence and for safety.
Slow down. Reduce your pace and lengthen your stroke.
Switch to an easier stroke. Backstroke or a relaxed breaststroke can give you a break.
Roll onto your back and float. A back float is a great way to rest and recover your breath.
Head to the wall. If you're in a pool, swim to the nearest edge and rest.
Tread water gently, if you've learned how.
Stop if something feels wrong. If you feel dizzy, faint, have chest pain, or experience unusual symptoms, stop immediately, get out of the water and seek help.
For beginners, I always recommend swimming where there is a lifeguard on duty and never swimming alone while you're still building endurance.
Common Mistakes That Hurt Endurance
Let me summarise the most common mistakes I see.
Holding the breath instead of exhaling steadily
Lifting the head and sinking the hips
Over-kicking with big, tense legs
Short, frantic strokes with no glide
Starting too fast and burning out
Not resting between lengths
Ignoring technique and focusing only on fitness
Swimming irregularly, with long gaps between sessions
Comparing yourself with others and pushing too hard
Training when overtired, which reduces quality and increases risk
If you recognise yourself in any of these, you're in good company. Just pick one to work on and keep going.
Equipment That Can Help
A few simple pieces of equipment may help your endurance training, though none is essential.
Well-fitting goggles: Leaky goggles are distracting and tiring. Find a pair that seals comfortably.
A kickboard: Useful for kick sets and building leg strength.
A pull buoy: A float placed between the thighs to support the legs, allowing you to focus on arm technique. Use it sparingly, as over-reliance can hide body position problems.
Fins: Can help with body position and kick technique, but should be used under guidance, as they may strain the ankles and hide weaknesses.
A swim cap: For comfort and hygiene, and to keep hair out of your face.
Ask your coach what's appropriate for you. Equipment is a tool, not a shortcut.
How Long Until Endurance Improves?
Everyone is different, so I can't give an exact timeline. But here are some general patterns I've seen.
Within a few weeks of regular practice and better breathing, many learners notice they feel less breathless.
Within a couple of months, with good technique and consistency, many can swim noticeably longer distances.
Over several months, endurance often builds steadily, especially if technique keeps improving.
Plateaus are normal. Progress isn't always smooth. Some weeks feel better than others.
Consistency, patience and good technique are the keys.
How SG Sink Or Swim Approaches Endurance
At SG Sink Or Swim, I always tell learners that endurance begins with technique and calmness, not with exhausting yourself. When someone says, "I get tired too quickly," I don't just tell them to swim more laps. I watch how they swim and look for where they might be losing energy: breathing, body position, kick, stroke length or tension.
Often, one or two small adjustments make a big difference. A learner who learns to exhale properly, or to keep their head down, may suddenly find that the same distance feels far easier.
I also believe in building endurance gradually and safely. We use short intervals, plenty of rest at first, and slowly extend distances as confidence grows. For children, we keep things playful and watch for signs of tiredness or cold. For adults, we focus on relaxation and efficient technique, and I'm always careful to respect each person's limits.
Most importantly, I want learners to enjoy the process. Endurance grows when swimming feels good, not when it feels like punishment. When people stop fighting the water and start working with it, they often surprise themselves with how far they can go.
Frequently Asked Questions
Why do I get tired so quickly when swimming, even though I'm fit?
Swimming uses different muscles and demands efficient technique and breathing. Fitness on land doesn't automatically transfer. Most often, the cause is technique, breathing or tension.
Is it normal to feel out of breath after one length?
Yes, especially for beginners. It usually improves with better breathing, relaxation and practice.
How can I breathe better when swimming?
Exhale steadily under water, turn your head to breathe instead of lifting it, and find a regular breathing rhythm. Practising bubbles helps a lot.
Should I kick harder to stay afloat?
Usually not. Over-kicking tires you out. Focus on body position and a small, relaxed kick.
How often should I swim to improve endurance?
Two to three sessions a week is a good target for many people, but even once a week with consistency helps. Listen to your body and rest when needed.
Do I need to build up fitness outside the pool?
It can help, but it isn't essential. Walking, cycling and gentle strength work can support your swimming. Check with your doctor if you have health concerns.
Why do my arms feel so heavy?
Common causes include tension, over-pulling, short strokes and poor breathing. Relaxing, lengthening your stroke and slowing down often helps.
What if I plateau?
Plateaus are normal. Try focusing on a new technique point, changing your training routine, or asking a coach to review your stroke.
Is it safe to push through tiredness?
Gentle fatigue is normal, but you should never push through dizziness, pain or panic. Stop, rest and get help if needed.
Final Thoughts
If you've been struggling with getting tired in the water, I hope this article has shown you that you're not alone, and that the problem can be fixed.
Let me recap the key points:
Swimming fatigue is usually about efficiency, not just fitness.
Breathing is the number one factor: exhale steadily and breathe rhythmically.
Good body position reduces drag. Keep your head neutral and hips high.
Kick small and relaxed. Over-kicking wastes energy.
Lengthen your stroke, glide and relax your hands.
Release tension in your shoulders, neck and jaw.
Pace yourself and use rests intelligently.
Build distance gradually with intervals, drills and consistency.
Rest, eat sensibly, stay hydrated and be patient.
A good coach can spot energy leaks you can't feel.
Endurance isn't something you're born with. It's something you build, one calm breath, one smooth stroke and one extra length at a time.
If you'd like help finding your own energy leaks and building endurance safely, I'd be glad to help. At SG Sink Or Swim, we'll look at how you swim, focus on what makes the biggest difference, and help you move through the water with less effort and more confidence.
Coach Tan Meng Chew (MC) is the coach behind SG Sink Or Swim, helping children and adults in Singapore learn to swim with confidence and safety.
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