Exercise guide
Sickle cell disease is an inherited condition of the red blood cells that can cause sudden episodes of severe pain, called crises, as well as tiredness and other complications. Exercise used to be discouraged, but the NHS (National Health Service) now suggests gentle to moderate activity, such as walking or yoga, and small trials have found regular moderate exercise safe. How you exercise matters most: plenty of fluids, regular rests, staying warm, and no very hard efforts.
Sickle cell trait, being a carrier, is not a disease and doesn't stop anyone playing sport. In very hard training it slightly raises the risk of a serious kind of muscle breakdown, so a few sensible precautions matter.
This guide covers what the trials show, how hard and how much to exercise, fluids, heat, cold, swimming and altitude, PE (physical education) and sport for children, sickle cell trait in sport, and the signs that need 999, with 3D demos and a gentle workout with rest and drink breaks.
The NHS suggests gentle to moderate exercise, such as walking or yoga, and avoiding high-intensity exercise because it may affect your breathing. In a French trial of 40 adults, 8 weeks of moderate cycling was safe and improved fitness, and in one small trial of 38 already-active men in Senegal, walking more eased pain.
You should be able to talk in full sentences. Start with 10 to 15 minutes and build to blocks of up to 20 minutes, with a rest and a drink between them (our editorial starting point, using a UK children's hospital's advice to rest every 20 minutes).
Drink before, during and after exercise, stop at the first sign of unusual tiredness, avoid sudden cold and very cold water, take care in hot weather, and don't exercise hard when you're ill.
Sprints, HIIT (high-intensity interval training) and circuits, heavy weights, holding your breath, underwater swimming, contact sports and exercising to exhaustion.
A crisis with severe pain, breathing difficulties or being sick; a high temperature; signs of a stroke; or an erection that is painful or won't go away (more than 1 hour, on the NHS priapism page).
Being a carrier isn't a disease. In intense sport, build up gradually, drink plenty, avoid extreme heat and exhaustion, and stop at once with cramping, unusual muscle pain or weakness.
The NHS sickle cell page lists these. Don't drive yourself to A&E (accident and emergency).
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Someone with sickle cell trait who slumps or can't carry on during hard exercise, with weak, painful legs, buttocks or lower back, needs emergency care even if they can still talk. Call 999.
An inherited condition that affects red blood cells and can cause pain, swelling and tiredness. Symptoms include pain in the bones, joints, muscles or chest, weakness and tiredness, swollen hands and feet, breathing problems and infections. It's more common in people with African, Caribbean, Mediterranean, south and south-east Asian and Middle Eastern backgrounds, and NHS Blood and Transplant calls it the UK's fastest growing genetic disorder. Babies are checked for it with the newborn heel prick test, and people with it have a care plan and regular check-ups.
A sickle cell crisis is sudden, severe pain or other symptoms lasting hours, days or weeks. The NHS lists dehydration, sudden changes in temperature and stress as triggers. The UK's travel health service adds cold, lack of oxygen, hard exercise, fever and infection, and a London hospital's leaflet notes that sometimes there's no trigger at all.
Very hard exercise makes the muscles more acidic, can dehydrate you and adds oxidative stress, and all of these could in theory make red cells sickle more. That's why exercise was long discouraged. In studies, mild to moderate exercise hasn't caused consistent changes in the red cells or frequent complications, and controlled training appears safe and well tolerated.
Peak fitness was about 30% lower in 60 children and young adults with sickle cell anaemia than in others of the same age, and an estimated 83% of adults have reduced exercise capacity. Anaemia means people can get breathless and tired quickly. In 223 adults, fitness didn't predict later crises or survival. Our reading: lower fitness is a reason to start gently, not a reason not to start.
Your team's advice comes first if you have:
The trials are few and small, mostly in adults without severe complications, with short follow-up.
In a French trial of 40 adults without severe complications, three 45-minute sessions of moderate cycling a week for 8 weeks improved fitness at everyday effort levels: the power they could hold at a set level of lactate rose by about 7 watts. Nobody in the training group needed hospital, against 5 admissions in the control group, 4 of them for crises. The training also improved the muscles' small blood vessels and how well they used oxygen. It's one small trial, with 33 people analysed.
In one small trial of 38 already-active men in Senegal, adding 25% to their usual daily steps for 8 weeks, or 25% and then 50%, eased how often and how badly they had pain, improved the distance they could walk in 6 minutes by 9% to 16%, and lowered artery stiffness, with no crises. The men already walked 3,000 to 10,000 steps a day, so the results may not apply to women, children or people who are less active.
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Across 7 studies with 176 people, endurance training improved physical function. A review of 6 studies (212 people aged 13 to 40) found exercise at a low to moderate level improved exercise tolerance without crises, and warned that going above that level could be harmful. Programmes included 30 minutes of treadmill walking 3 times a week for 12 weeks in 60 adults, and home cycling in 13 children. None of the studies tested strength training alone, swimming or team sport.
Across 24 studies with 939 people, maximal exercise tests caused problems in 3.8%, mostly brief changes on the heart tracing or in oxygen levels, and pain episodes in 4 people. So a test can safely guide a programme.
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In a survey of 100 children with sickle cell disease, 17% did 60 minutes a day of moderate to vigorous activity, against 23% of US children generally, though 90% took part in PE. Only 2 studies have tested ways to help children with sickle cell disease be more active.
The NHS recommends gentle to moderate exercise. The American Society of Hematology's 2020 pain guideline made no recommendation for or against exercise, yoga or Pilates for long-term sickle cell pain, because the evidence was too thin. For acute pain it suggests yoga, massage or guided relaxation alongside medicines, a weak recommendation on very low-certainty evidence.
Exercise supports your general health but doesn't treat sickle cell disease. The NHS lists the treatments: painkillers, antibiotics and vaccinations to prevent infections, hydroxycarbamide, which can help reduce pain crises, and blood transfusions, with a stem cell transplant or gene therapy for some people.
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Gentle to moderate: you can talk in full sentences and you're never gasping. That's our reading, a little more cautious than the NHS's usual test for moderate exercise (you can talk but not sing), because the trials stayed at or below a moderate level. With a heart rate monitor, the treadmill trial used 60% to 70% of maximum heart rate; our heart rate zone calculator estimates yours.
Start with 10 to 15 minutes (our editorial starting point). A UK children's hospital recommends a rest every 20 minutes of exercise, so build to blocks of up to 20 minutes with a rest and a drink between them, and over the weeks towards 30 to 45 minutes in total, 3 times a week, as in the trials.
An easy way in: find your usual daily steps over a week or two with a phone or tracker, add 25% for 4 weeks, then up to 50%. This comes from one small trial in active men.
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Light to moderate strength work on 2 days a week, as for all adults: programmes that included resistance training improved muscle function. Avoid heavy weights and holding your breath. Start with 1 or 2 sets of 10 to 15 with a band, light weights or your bodyweight, breathing out on the effort and stopping well short of failure (our editorial starting point).
Warm up and cool down for 5 to 10 minutes each time. Ask your sickle cell team before harder exercise, competitive sport or a new programme; an exercise test can safely guide one.
The NHS and a UK children's hospital advise against:
Start with 10 to 15 minutes at a pace where you can talk in full sentences, building to blocks of up to 20 minutes with a rest and a drink between them (our editorial starting point, within the trials' 30 to 45 minute sessions).
Twice a week: 1 or 2 sets of 10 to 15, breathing out on the effort and stopping well short of failure (our editorial starting point). Skip the step-up while hip pain is being checked.
Yoga and breathing exercises to relax, as the NHS suggests, all without breath holds. Keep the room warm, and hold the tree pose near a wall.
3D demoMountain pose (Tadasana)Beginner · No equipment
3D demoCat-cowBeginner · No equipment
3D demoSupine spinal twist (Supta Matsyendrasana)Beginner · No equipment
3D demoTree pose (Vrksasana)Beginner · No equipment
3D demoChild's Pose (Balasana)Beginner · No equipment
3D demoSlow breathing (6 breaths a minute)Beginner · No equipment
3D demoLateral breathing (Pilates breathing)Beginner · No equipment
3D demoCrocodile breathing (prone diaphragmatic breathing)Beginner · No equipmentStart with the gentle workout, which builds in rest and drink breaks. Split easy cardio into blocks of up to 20 minutes, skip the breath holds (box and 4-7-8 breathing) in the breathing routine, and let children do the animal moves at their own pace with drinks and rests. Not for sickle cell disease: HIIT, Tabata, circuits and sprint workouts.
A 35-minute gentle workout for sickle cell disease: two 10-minute walking or cycling blocks with rest and drink breaks, light strength and slow breathing.
35 minBeginner12 movesCardio machine, A bench or boxA 10-minute session for low-energy days: marching, sit-to-stands, wall push-ups, step-ups and bridges, then a short walk. Doing a little counts.
10 minBeginner7 movesA bench or box, A wallA steady 30 to 45 minute cardio session at talk-but-not-sing pace: walk, cycle, row or cross-train, counting toward weekly activity guidelines.
40 minBeginner3 movesCardio machine, A wallA 10-minute routine for straight after a meal: an easy walk, a few simple standing moves from blood sugar trials, then a short walk to finish.
10 minBeginner6 movesCardio machine, A bench or boxA 25-minute standing cardio circuit with no jumping: marching, step jacks, sit-to-stands, punches, step-ups and wall push-ups, with a seated option for most moves.
25 minBeginner9 movesA bench or box, A stepA 25-minute gentle yoga class for complete beginners and over-50s: slow breathing, a warm-up, supported standing poses, floor poses and a closing rest.
25 minBeginner14 movesNo equipmentA 45-minute session for weight loss and health: a 20-minute brisk walk, which does more for the scales, then a standing yoga flow for strength and balance.
45 minBeginner12 movesCardio machineA free 20-minute chair yoga class for older adults: slow breathing, gentle seated stretches and twists, standing poses holding the chair, and a calm finish.
20 minBeginner18 movesA bench or box, Something with weightA 6-minute breathing routine: slow breathing, crocodile breathing, alternate nostril breathing, box breathing and 4-7-8 breathing.
6 minBeginner5 movesNo equipmentFifteen minutes of animal moves, jumps and balance games for children, building the muscle- and bone-strengthening activity they need, with nothing to buy.
15 minBeginner16 movesA wallThe walking plan builds up slowly; repeat a week whenever you need to, and keep the rest and drink breaks (our suggestion).
Drink before, during and after exercise, and plenty every day. Pale pee through the day is a simple check.
Avoid sudden changes in temperature: dress warmly in cold weather and avoid very cold water. Cold air, wind and water can trigger a crisis, so wear warm layers outdoors.
Warm pools only. Get dried, hair included, and dressed as soon as you get out, and leave out underwater swimming and breath-holding games.
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Take care in hot weather: people with sickle cell disease run short of fluid more easily in heat and sun. Exercise early or late on hot days, or indoors (our suggestion). Heat exhaustion should improve within 30 minutes of resting somewhere cool, cooling down and drinking; call 999 if it doesn't, or for a very high temperature, hot skin that isn't sweating, a fast heartbeat, fast breathing, confusion, a fit or loss of consciousness.
The UK's travel health service says travel above 2,000 metres may trigger a crisis and should be avoided with sickle cell disease. Some ski resorts and mountain walks go above that height, so talk to your sickle cell team before a trip.
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Cabin air has less oxygen, and extra oxygen is sometimes recommended. Wait at least 10 days after a crisis before flying, and keep moving on long flights to lower the risk of clots.
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The sources we read don't cover scuba diving with sickle cell disease, and the children's leaflet advises against underwater swimming. Ask your team before you try it (our suggestion).
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A UK children's hospital says children with sickle cell can usually exercise and play normally, with the precautions above, and 90% already take part in PE. Restricting exercise without weighing the benefits can harm fitness, and holding children back can leave them isolated and knock their confidence.
A 2026 review for children's doctors says guidance for sickle cell disease aims to encourage regular, safe exercise, while for sickle cell trait the aim is to prevent serious muscle breakdown and collapse in very hard exercise.
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In England, schools must support pupils with medical conditions to take a full part in school life, including PE and trips, agree an individual healthcare plan when needed, and must not stop pupils drinking, eating or taking toilet or other breaks whenever they need to. Put fluids, rest breaks, warm clothing, swimming and what to do in a crisis in the plan (our suggestion).
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If you're ever worried about your child, contact their sickle cell team or take them to A&E. A high temperature in a child with sickle cell disease means 999.
Don't exercise. A London hospital's leaflet says a mild painful crisis can sometimes be managed at home with painkillers, rest, fluids and warmth, as your team advises; NICE (the National Institute for Health and Care Excellence) treats a painful episode in hospital as a medical emergency.
Restart with short, easy walks once the pain has settled and you feel back to your usual, then build up over a week or two (our suggestion). After a hospital stay, acute chest syndrome, a stroke or priapism, ask your team before you restart. Wait at least 10 days before flying.
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Alongside medicines, yoga, massage or guided relaxation may help with acute pain (a weak recommendation on very low-certainty evidence), and the NHS suggests breathing exercises to relax.
For long-term sickle cell pain, the American Society of Hematology suggests cognitive and behavioural pain strategies, and made no recommendation either way on exercise for lack of evidence. One small trial since then found less pain with more walking: promising, not proven. Our chronic pain guide covers pacing and flare-ups, and our avascular necrosis guide covers hip pain.
A carrier has one sickle gene and one usual gene. Being a carrier doesn't make you ill, and you can't develop sickle cell disease, though you could pass the gene on. Tell staff before a general anaesthetic. Babies in the UK are screened at birth, and adults can ask a GP (general practitioner) for a carrier test.
The NHS carrier leaflet says that in any intense sport you should drink plenty of fluids, avoid extreme exhaustion and never be short of oxygen. US sports bodies and an expert panel add:
Older studies found a large relative risk of death during hard training. In US basic training from 1977 to 1981, sudden unexplained deaths were 32 per 100,000 Black recruits with the trait against about 1 per 100,000 Black recruits without it, and from 2004 to 2008 top-division US college football players with the trait had 37 times the risk. But in 47,944 US Army soldiers training under precautions against exertional injury from 2011 to 2014, death rates were the same with and without the trait, though exertional rhabdomyolysis was about 50% more common. In US college football, deaths linked with the trait fell after screening and education began in 2010; it's unclear which made the difference. The absolute risk is small.
A review of 41 studies found moderate-strength evidence that the trait raises the risk of exertional rhabdomyolysis, with small absolute risks. An expert panel found no evidence that it causes sickle cell pain crises, or sudden death without exertional rhabdomyolysis. Heat illness was slightly more common in military carriers.
A rare, severe form of exertional rhabdomyolysis, during intense effort with little recovery, often early in a session or season and sometimes after only a few minutes of sprinting. The person usually slumps but can still talk, with growing pain and weakness in the legs, buttocks or lower back and breathlessness, and their temperature is lower than in heatstroke. It's an emergency: call 999.
In the US, the NCAA (National Collegiate Athletic Association) requires college athletes to show a test result or sign a waiver. The American Society of Hematology opposes testing as a condition of playing and recommends precautions for every athlete. In the UK, after two Army candidates collapsed and died during a 2,000-metre best-effort run in 2019, the Ministry of Defence began screening candidates and gave carriers a 4-week build-up course with heart rate monitors; carrying the trait doesn't bar entry.
The trait doesn't usually cause problems on a plane, but at altitude avoid over-exertion, drink well and limit heat stress. Rarely, part of the spleen can be damaged at altitude: 13 cases have been reported in Japan, mostly on Mount Fuji. An expert panel recommends acclimatising before activity at moderate or high altitude.
The NHS says a painful erection lasting more than 1 hour with sickle cell disease needs 999 or A&E; a London hospital's leaflet says more than 4 hours. We use the NHS figure.
A children's leaflet advises against heavy weights; reviews report benefits from programmes that include resistance training. Light to moderate strength work fits both.
The NCAA requires testing; the American Society of Hematology opposes it. Both agree that precautions matter.
UK travel advice says the trait isn't usually a problem on planes but to take care at altitude; the NCAA advises easing training from altitude gains of as little as 2,000 feet (about 600 metres), and an expert panel recommends acclimatisation programmes. Our reading: acclimatise, and ease off.
Contact your sickle cell team or go to A&E for any of these (a London hospital's list for adults); the NHS says call 999 for a high temperature, or for a crisis with severe pain, breathing difficulties or being sick. For children: if you're ever worried, contact their sickle cell team or go to A&E.
Your sickle cell team (adult or children's haematology), your GP and NHS 111. The NHS lists the Sickle Cell Society, Contact and Sickle Cell and Young Stroke Survivors for support.
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The NHS advises gentle to moderate exercise, such as walking or yoga, and small trials found regular moderate exercise safe. Restricting exercise without weighing the benefits can harm fitness and, in children, leave them feeling left out.
Hard exercise, cold and dehydration are known triggers. But moderate training didn't raise crises in trials: there were no admissions in the training group against 5 in the control group in one, and no crises with more walking in another.
Warm pools are fine with precautions: get dry, hair included, and dressed straight away, and avoid cold water and underwater swimming.
Children can usually exercise and play normally with the precautions, and schools in England must support pupils with medical conditions to take part in PE and sport.
Carriers don't have sickle cell disease and can't develop it.
An expert panel's systematic review found no evidence that the trait causes sickle cell pain crises.
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An expert panel found no reason to stop carriers playing sport and says they should be encouraged to take part. With precautions in place, 47,944 US soldiers with and without the trait had the same risk of death.
The NHS says sickle cell disease is more common in people with African, Caribbean, Mediterranean, south and south-east Asian and Middle Eastern backgrounds.
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Yes. The NHS suggests gentle to moderate exercise, such as walking or yoga, and avoiding high-intensity exercise. Small trials found regular moderate exercise safe, with better fitness and, in one small trial, less pain.
Walking, cycling, yoga and light strength work, at a pace where you can talk in full sentences. Choose something you enjoy and can keep up: the trials used sessions of 30 to 45 minutes, 3 times a week, built up gradually.
Hard exercise, dehydration and sudden cold are known triggers. Moderate exercise with plenty of fluids and rest breaks hasn't raised crises in trials: in one, nobody in the training group needed hospital, against 5 admissions in the control group. Stop at the first sign of unusual tiredness or pain.
Drink before, during and after exercise, and rest at least every 20 minutes. Drink more in hot weather, when it's easier to run short of fluid. Pale pee through the day is a simple check.
Yes, in a warm pool. Get dry, hair included, and dressed as soon as you get out, and avoid cold water, underwater swimming and breath-holding games.
Usually yes: children with sickle cell can usually exercise and play normally with the precautions. In England, schools must support pupils with medical conditions in PE, trips and sport, and let them drink and take breaks whenever they need to, so agree an individual healthcare plan with the school.
Light to moderate strength work is fine, and programmes that included it improved muscle function. A UK children's hospital advises avoiding heavy weights and holding your breath, so breathe out on the effort and stop well short of failure.
The UK's travel health service advises avoiding travel above 2,000 metres with sickle cell disease, because it may trigger a crisis, and waiting at least 10 days after a crisis before flying. Talk to your sickle cell team before a ski or mountain trip.
Carriers don't have the disease and should be encouraged to play sport. In very intense training the trait slightly raises the risk of exertional rhabdomyolysis and, rarely, a dangerous collapse. With precautions in place, a study of 47,944 US soldiers found no difference in death rates.
Build fitness gradually, drink plenty, rest between repeats, and avoid all-out efforts and timed runs early in a season. Ease off in heat and at altitude, don't train hard when ill, and stop at once and tell a coach for cramping, muscle pain, weakness or breathlessness.
Babies in the UK are screened at birth, and adults can ask a GP for a carrier test. Some sports bodies, such as the NCAA in the US, require a test or a signed waiver; the American Society of Hematology opposes testing as a condition of playing and recommends precautions for everyone.
For a crisis with severe pain, breathing difficulties or being sick; a high temperature; an erection that is painful or won't go away (more than 1 hour, on the NHS priapism page); or signs of a stroke. Chest pain or new breathing problems can be acute chest syndrome, which needs urgent treatment. Don't drive yourself to A&E.
Exercise education, not a diagnosis or treatment plan, and clinical review of these guides is pending. Stop and get advice for chest pain, unusual breathlessness, dizziness or fainting, or new pain, and check with your doctor or midwife first if they have told you to limit activity. Health disclaimer.
