Training guide
Your quadriceps are four muscles at the front of your thigh that straighten your knee and control it on stairs, in squats and when you land. Strengthening them takes a squat or the leg press, a single-leg move such as split squats or step-ups, and a move that works the quads on their own, such as the leg extension, 2 or 3 times a week.
Squats and leg extensions do different jobs: leg extensions grew the rectus femoris, the quad muscle that crosses your hip, 13% in 12 weeks against 1% for the leg press. Weaker quads go with knee arthritis later, and exercise eases sore knees, though modestly.
This guide covers the four muscles, the quad strengthening exercises with doses, leg extensions and your knees, bad knees, knee replacements and ACL (anterior cruciate ligament) surgery, and when knee pain needs its own plan first.
A squat or the leg press, a single-leg move such as split squats or step-ups, and a move that works the quads on their own, such as the leg extension. Your four quad muscles straighten your knee, and one of them, the rectus femoris, also crosses your hip.
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Leg extensions grew the rectus femoris 13.2% in 12 weeks against 1.1% for the leg press, while the other three quad muscles grew about equally on both. Do both if you can.
They load the knee differently, not dangerously: more behind the kneecap and on the ACL near straight, less with the knee well bent. With a sore kneecap, use the bent half of the range.
Weaker quads go with higher odds of painful knee arthritis later, a link from low-quality evidence. Exercise eases knee arthritis pain modestly, and heavy training eased it no more than light training in a large trial.
Two or 3 sessions a week, 2 or 3 sets of 8 to 15 per move, stopping 2 or 3 reps short of failure, within our knee guides' pain rule. The World Health Organization (WHO) asks for strength work on 2 or more days a week.
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Quad strength falls sharply after a knee replacement and is the long project after ACL surgery, so follow your team and our surgery guides. A pop with fast swelling, a knee that locks or gives way, or pain and swelling in one leg isn't a strengthening job: see the warning signs.
The vastus lateralis (outer), vastus medialis (inner) and vastus intermedius (deep) cross only the knee; the rectus femoris crosses the hip as well and helps lift the thigh. All four join above the kneecap and, through the kneecap and the tendon below it, straighten the knee. Our quadriceps, rectus femoris and vastus medialis pages have the anatomy.
They straighten the knee and control it as it bends under load: standing up, sitting down, stairs (going down most of all), squatting and landing. The rectus femoris also kicks and drives the knee forward when you sprint.
Squats and the leg press straighten both the knees and the hips: the three vasti, the glutes and the inner thighs grow, but the rectus femoris barely does. Single-leg moves (split squats, step-ups, step-downs, lunges) train the same muscles one leg at a time, with balance and knee control. Moves for the quads on their own (leg extensions, chair knee extensions, straight-leg raises, the Spanish squat, reverse Nordics) reach the rectus femoris too, and load the quads when squatting hurts.
Physiotherapists call the leg extension open chain, because the foot moves freely, and the squat closed chain, because the feet push against the floor. They load the knee in different ways, which is where the worry about leg extensions comes from.
Long thighs or stiff ankles mean more forward lean or more knee travel in a squat, which is normal, as our knee guide says. Weak quads went with later knee arthritis in women and men, though in one study the link in women disappeared once body mass index was accounted for. No knee, hip or foot position isolates the inner quad (the VMO, vastus medialis obliquus), as our knee guide explains.
This guide is about strength for everyday life, sport and sore knees. Our bigger legs guide covers size, and our knee strengthening guide covers the whole knee.
Most training trials here are 8 to 12 weeks in untrained young adults; the knee trials are in people with arthritis, kneecap pain or after surgery.
In 17 untrained adults training one leg on each machine, 5 sets of 10 twice a week for 12 weeks, the rectus femoris grew 13.2% with leg extensions against 1.1% with the leg press, while the other quad muscles grew 4 to 7% on both and the leg press also grew the glutes. In 63 untrained women over 8 weeks, leg extensions grew the rectus femoris 11 to 18% against 2 to 8% with Smith machine squats, and the squats grew the lower outer quad more. Another trial agreed, and full or half squats didn't grow the rectus femoris in 10 weeks.
In 11 cohorts of 46,819 people followed for 2 years or more, weak quads went with higher odds of painful knee arthritis in women (1.85) and men (1.43), from low-quality evidence. In people who already have knee arthritis, weaker quads predicted more pain and worse function, but not narrowing of the joint on X-ray. Links like these aren't proof that strengthening prevents arthritis.
In a review of risk factors, weak quads predicted kneecap (patellofemoral) pain in military recruits; weak hips didn't.
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WHO and the NHS ask adults for strength work for all the major muscle groups on 2 or more days a week. The NHS's strength exercises start sit-to-stands at 5 slow repetitions and aim the knees over the big toe in a mini squat, and NHS inform's knee exercises keep pain at 0 to 5 out of 10 and build to a maximum of 2 sets of 15.
Two or 3 sessions a week, not on back-to-back days, as our knee guide says, with leg extensions once or twice a week after squats or the leg press, as our leg extension guide suggests.
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Two or 3 sets of 8 to 15 per move (our knee guide's editorial starting point), and 2 to 3 sets of 10 to 15 for leg extensions (our leg extension guide). In your first two weeks, stop every set with 3 or 4 reps to spare, as our plans' notes say.
Stop squats and split squats 2 or 3 reps short of failure, which our guides call 2 or 3 RIR (reps in reserve: how many more reps you could have done); the last set of leg extensions can go to 0 to 2. Rest 2 to 3 minutes between heavy squat sets, 90 seconds to 2 minutes for other squats and single-leg work, and 60 to 90 seconds for leg extensions, as our plans' notes say.
Go as deep as you can control without pain. With kneecap pain, squat to about 45 degrees of knee bend first and do leg extensions from 90 to 45 degrees, the ranges that kept stress behind the kneecap low in a lab study, then add range as it settles, as our knee guide suggests.
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Add reps until every set reaches the top of its range, then add the smallest weight step, as our plans' notes say. With sore knees, add depth before load, as our knee guide says.
Strength rises within weeks, but knee pain changes more slowly and modestly, and the arthritis trials ran for months. Treat 12 weeks as a first block, as our knee guide does.
Pain from 0 to 2 out of 10 is fine, and up to 5 is acceptable if your knee is back to its usual level by the next morning; for tendon pain just below or above the kneecap, keep it to 3 or less. Sharp, catching or giving-way pain, or new swelling, means stop. That's our knee guides' rule.
Our editorial order, built on our knee strengthening workout and knee guide, with doses from our plans' notes and our knee, leg extension and legs guides. Our split squat guide teaches the move shown.
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The movement on the figure: Split squat
Sit-to-stands, 3 sets of 8 to 12; bodyweight squats, 3 sets of 10 to 20; goblet squats, 3 or 4 sets of 8 to 12; the leg press, 3 sets of 8 to 12; wall sits of 30 seconds (our knee guide). Back squats, 4 sets of 6 once you're trained (our bigger legs guide). Heels raised let your knees travel further forward: 2 sets of 6 to 8, deeper over the weeks (our knee strengthening workout).
3D demoSit to stand from a chairBeginner · A bench or box
3D demoBodyweight squatBeginner · No equipment
3D demoDumbbell goblet squatIntermediate · A dumbbell
3D demoLeg pressBeginner · Strength machine
3D demoWall sitBeginner · A wall
3D demoBarbell back squatAdvanced · A barbell
3D demoHeel-elevated deep squat (slant board squat)Intermediate · A stepStep-ups and slow step-downs, 8 each side; split squats, 2 or 3 sets of 8 to 12 each leg; reverse lunges, 3 sets of 8 to 12; Bulgarian split squats, 3 sets of 6 to 10 each leg (our knee, legs and hips guides).
Quad sets, 3 sets of 10 holds of 5 seconds, and straight-leg raises, 3 sets of 10 holding 5 seconds (our leg extension guide). Chair knee extensions: the move page's dose is 3 sets of 10 to 15 each leg, 2 to 3 days a week. Leg extensions, 2 to 3 sets of 10 to 15 (our leg extension guide); reverse Nordics, 2 sets of 3 to 5 in a small range (our knee strengthening workout). With a sore kneecap, use the bent half of the range, from about 90 to 45 degrees of knee bend.
3D demoQuad set (static quads)Beginner · No equipment
3D demoStraight-leg raiseBeginner · No equipment
3D demoSeated knee extension (chair)Beginner · A bench or box + Something with weight
3D demoLeg extensionBeginner · Strength machine
3D demoSingle-leg leg extensionBeginner · Strength machine
3D demoSpanish squat (band squat hold)Intermediate · A band + An anchor point
3D demoReverse NordicAdvanced · No equipment
3D demoWeighted sissy squatAdvanced · Weight plates + A wallIn lab studies, the leg extension put tension on the ACL only near full straightening, and loads on the ACL were generally higher without weight through the feet, peaking between 10 and 30 degrees of bend. Stress behind the kneecap was higher in the leg extension near straight and higher in the leg press when well bent, crossing at about 48 degrees. These are lab studies, not studies of injuries.
Leg extension type and squat type programmes both eased kneecap pain at 5 weeks in a trial of 60 people, and the leg extension type was ahead at 5 years in a trial of 49.
Leg extensions didn't loosen the knee more than squat-type exercise in 10 trials, and may build quad strength faster, at very low to low certainty. The Aspetar guideline allows them in a limited range, 90 to 45 degrees of knee bend, from the fourth week after surgery. Your rehab team sets the stages.
Line your knee up with the pivot, straighten until nearly straight, and lower over 2 to 3 seconds. Our leg extension guide covers the machine and its settings.
In a 2024 Cochrane review of 139 trials (12,468 people), exercise eased knee arthritis pain by about 13 points out of 100 against no treatment (low certainty), and 8.7 points against placebo, benefits the authors called of uncertain clinical importance. NICE recommends therapeutic exercise, such as local muscle strengthening, for everyone with osteoarthritis, and warns that joint pain may increase at first.
In 377 adults aged 50 and over with knee arthritis, training 3 times a week for 18 months, heavy training eased pain no more than light training, though it built more strength, and pain improved by about a third even in the comparison group. Across 45 trials, strength-focused programmes built more quad strength but didn't ease more pain; strength may need to rise by 30 to 40% before pain changes.
Comparing across trials, quad-focused programmes eased more arthritis pain than general leg programmes, and supervised exercise 3 or more times a week did better; a later Cochrane review found no link with the number of sessions.
Exercise cut kneecap pain during activity by about 1.5 points out of 10 across 31 trials, very low quality but consistent. Hip and knee strengthening together beat knee strengthening alone by about 1.5 points, with no measurable change in strength, and the 2016 consensus recommends combining them.
Thigh holds eased patellar tendon pain dramatically in 6 volleyball players, but later trials found holds no better than ordinary lifting, and a wall squat changed pain sensitivity but not pain in 90 people with knee arthritis. Our jumper's knee and quadriceps tendinopathy guides keep tendon pain at 3 out of 10 or less.
Our knee strengthening guide has the full plan for sore knees, and our knee arthritis, runner's knee and knee pain when squatting guides have their own.
In 20 people 27 days after surgery, quad strength was down 62%, mostly because the muscle wouldn't switch on fully. Across 18 trials, physiotherapy exercise improved function and pain at 3 to 4 months. The NHS asks you to keep doing your physiotherapist's exercises, which help the long-term strength and movement in your knee.
Heavier, earlier strength work was safe and built more strength (43% more knee-straightening strength in one trial) but didn't improve walking or function more than standard rehab in three trials, and 4 weeks of strength training before surgery added a little to chair-stand scores afterwards. These are small trials and the evidence is low certainty: follow your physiotherapist and our knee replacement guide.
In 106 people followed for 2 years after ACL reconstruction, each percentage point closer to the other leg's quad strength went with a 3% lower reinjury rate, and each month's delay in returning to sport, up to 9 months, cut reinjury by 51%. Our ACL surgery guide covers the stages.
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Follow your surgical team's limits. Our knee replacement, hip replacement and ACL (anterior cruciate ligament) injury guides cover the stages.
One-leg stands of 30 seconds, snapdowns, 2 sets of 5 holding each landing, and hop and stick once two-foot landings are steady (our knee guide). Our knee control warm-up puts landing work before sport. The standing quad stretch is for comfort after training.
The knee strengthening workout is a quad-first home session, from the chair to the reverse Nordic; the machine leg and leg day workouts suit a gym; the sissy squat progression works the quads on their own. The low-impact and seniors' sessions suit sore knees and older adults.
A 25-minute session for knees that don't currently hurt: thigh and hamstring strength, single-leg control, then an optional full-range block with knees over toes.
25 minBeginner14 movesA bench or box, A wallA 45-minute leg day on machines only: the leg press, then leg extensions and seated leg curls for the muscles it misses, hip abduction and calf presses.
45 minBeginner10 movesCardio machine, Strength machineA gym leg day: back squats, leg press, leg curls, Bulgarian split squats, leg extensions and calf raises.
55 minIntermediate9 movesA wall, A barbellBuild to a sissy squat: knee and ankle prep, the reverse Nordic, sissy squats holding a support, then the weighted version, with a single-leg step-down.
25 minIntermediate8 movesA wall, A stepA 25-minute practice session for the squat: find your depth on a chair, groove the bodyweight squat with pauses, then load it with a slow goblet squat.
25 minBeginner8 movesA wall, A bench or boxA 30-minute step-up workout at home or in the gym: step-ups, split squats, step-downs and calf raises on one step, with the height set to your level.
30 minBeginner9 movesA wall, A stepA 25-minute session from the split squat to the walking lunge: ankle and balance prep, slow split squats, reverse lunges, then walking lunges.
25 minBeginner11 movesA wall, A bench or boxA heavy squat session for lifters past the beginner stage: heavy back squats, paused back-off sets, Bulgarian split squats, Romanian deadlifts and dead bugs.
60 minIntermediate8 movesA wall, A barbellA gentle leg strength routine with no jumping: sit-to-stands, step-ups, wall sits, bridges and calf raises.
20 minBeginner7 movesA bench or box, A stepA 50-minute gym session for older adults and sarcopenia: 7 machines for the legs, chest and back from the UK prescription, then a short balance finish.
50 minBeginner12 movesCardio machine, A bench or boxA 40-minute strength and balance session for over-65s, built from the Otago home programme and NHS exercises, using a chair, a counter and a step.
40 minBeginner18 movesA bench or box, Something with weightA 20-minute seated workout for older adults who cannot stand for long: marching, leg and arm strength, posture, and sit-to-stands that lead back to standing.
20 minBeginner11 movesA bench or box, Something with weightA 20-minute warm-up that trains your knees to track over your toes: side-hip strength, squats and lunges with alignment practice, balance and quiet landings.
20 minBeginner10 movesA wall, A bandA 25-minute Pilates class for sore knees and knee arthritis: lying and side-lying leg work, shallow squats and balance, with no kneeling at all.
25 minBeginner15 movesA bench or box, Something with weightA 25-minute knee-friendly yoga practice with no kneeling and no deep bends: shallow standing poses, hip and thigh strength on the floor, and supported stretches.
25 minBeginner15 movesFirm cushionThe squat challenge builds bodyweight squats; the runners', seniors' and split plans have squat-led days.
A free 30-day squat challenge with a chair track and a single-leg track: 3 short sessions a week, optional practice days and a before-and-after test.
3 training days15 minBeginner2 days a weekA 12-week strength plan for runners: two sessions a week of heavy lifts, single-leg work, calf raises and hops, fitted around your runs.
2 training days45 minBeginner3 days a weekA 12-week exercise plan for over-65s: strength and balance three times a week, short balance sessions and daily walks, based on falls-prevention trials.
3 training days40 minBeginner4 days a weekA 4-day upper/lower split: two upper body and two lower body gym days, each muscle trained twice a week, with sets, reps and progression.
4 training days50 minIntermediate2 days a weekTwo full-body strength sessions a week: the minimum that meets health guidelines, with every set, rep and rest, and an 8-week progression.
2 training days45 minBeginnerUse the bent half of the leg extension and squat to about 45 degrees first, adding range as it settles, and add hip strengthening, as our runner's knee guide does.
Keep it to 3 out of 10 or less, as our knee guides' rule says, and follow our quadriceps tendinopathy or jumper's knee guide.
Wall sits raise blood pressure while you hold them, so breathe normally and never hold your breath. Ask your GP first if your blood pressure is 160/100 or higher and untreated, or if you have heart disease, and skip them with Marfan syndrome, vascular Ehlers-Danlos syndrome or aortic disease.
Our suggestion: treat the Spanish squat the same way, since it's a similar hard hold.
The leg extension is seated, so it suits later pregnancy too, as our leg extension guide suggests. Don't hold your breath, and this isn't the time for your heaviest weights.
Skip reverse Nordics if kneeling hurts, as our knee strengthening workout says.
Start with sit-to-stands, chair knee extensions and step-ups by a counter, and add balance work. Our exercise for older adults guide has the plan.
Go to A&E (accident and emergency) if you've injured your knee and it has changed shape, it becomes very swollen very quickly, you felt a pop or snap, you can see bone sticking out, or it's bleeding heavily. Don't drive yourself: ask someone to take you, or call 999 if the pain means you can't move your leg to get there.
Get advice from NHS 111 now: you cannot move the knee or put any weight on it, or it is very painful, badly swollen or has changed shape.
Get advice from NHS 111 now: the knee locks, gives way or clicks painfully. Painless clicking is normal.
Get advice from NHS 111 now: a hot, red or swollen knee with sudden severe pain, a very high temperature, or feeling hot, cold or shivery. This can be a joint infection.
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You hurt your knee and cannot take 4 steps, or you are 55 or over and have injured it: get it checked the same day for a broken bone.
A pop or tearing feeling at the front of the knee after a fall, a jump, a landing or a heavy squat, then you can't straighten the knee or lift the straight leg, there's a dent above or below the kneecap, or the kneecap sits higher or lower than on the other side. Go to A&E or an urgent treatment centre, or get help from NHS 111, as our knee pain when squatting guide explains. In the US, go to urgent care or the emergency department.
Same day: a pop just above the kneecap, then you can't straighten your knee or lift the straight leg, or there's a dent above the kneecap. This can be a quadriceps tendon tear, which almost always needs surgery and does better if it's repaired soon. Our torn kneecap tendons guide covers that injury.
Same day (urgent GP appointment or NHS 111): throbbing pain in one leg (rarely both), usually the calf or thigh; swelling in one leg (rarely both); red, blue or darkened skin; or swollen veins; or sudden worse pain and swelling around a lump at the back of the knee (a possible clot or a burst Baker's cyst).
Also call 999 for pain and swelling in one leg with breathlessness or chest pain: it can be a blood clot that has reached the lungs.
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Call 999 or go to A&E: sudden, severe pain in a thigh muscle, which may be worse when you stretch it (for example bending the knee), with swelling, numbness, weakness or pins and needles, or tightness or difficulty moving the leg. This can be acute compartment syndrome, which needs surgery as soon as possible. In the thigh it usually follows a heavy knock, a crush or a broken bone. Do not drive yourself to A&E.
Call NHS 111 (in the US, your doctor or urgent care) for severe muscle pain and weakness with dark (cola-coloured) or reduced urine after unusually hard training. This can be rhabdomyolysis, which can harm the kidneys and needs prompt care.
Knee pain that has not improved within a few weeks of looking after it at home. Many areas offer NHS physiotherapy without a GP referral.
If you get chest pain or pressure, feel faint or dizzy, are unusually breathless, or your heart races or beats irregularly during exercise, as our plans advise.
For chest pain that comes on suddenly and doesn't go away, feels tight or like squeezing, spreads to your arms, neck, jaw, stomach or back, or comes with sweating, feeling sick, light-headedness or breathlessness; severe difficulty breathing; someone who faints while exercising; palpitations that don't go away, or come with chest pain, shortness of breath or feeling faint; or a headache that starts suddenly and is extremely painful, especially while lifting or straining, or comes with numbness or weakness, difficulty speaking or loss of vision. The NHS says a bleed on the brain may be more likely when lifting something heavy. Don't drive yourself to A&E.
Ask for an urgent GP appointment or get help from NHS 111 for a headache that's triggered or made worse by coughing, sneezing, bending down or exercising. In the US, contact your doctor or urgent care.
Stop straight away if you feel any pain or become unwell, the NHS says, and contact 111 if your symptoms worry you or don't go away.
A dull ache in your muscles for a day or two after something new is normal. Joint pain that's sharp, gets worse during a set or lingers into the next day means switching to the easier option, and seeing a GP or physiotherapist if it carries on (our plans' rule). Our muscle soreness guide has more.
Speak to your GP first if you haven't exercised for some time or have medical conditions or concerns, as the NHS advises. Get advice before heavy lifting or hard straining work if your blood pressure is uncontrolled, or you have heart disease or chest pain when you're active, a pacemaker or defibrillator, diabetic eye disease, glaucoma, a hernia, recent eye or tummy surgery, or you're pregnant, as our breathing guide lists. After a recent shoulder dislocation or shoulder surgery, follow our shoulder dislocation guide or your surgical team first.
Speak to a GP first if you haven't exercised for some time, or if you have a medical condition or concerns. Get advice first, too, if you have a health problem, an injury or symptoms, have recently had a heart attack or an operation, or are pregnant or have recently given birth.
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See a GP if you think you have a hernia, a bulge or lump that may get bigger when you strain and smaller when you lie down. Get help from NHS 111 if you have a hernia and pain in or around it, a bloated tummy, you feel or are sick, you're vomiting blood or your vomit looks like coffee grounds, you're constipated, you have a high temperature or feel hot, cold or shivery, or you've suddenly become confused. Call 999 or go to A&E for a femoral hernia (a small lump at the top of your thigh, in your groin) with very bad tummy pain, sickness, being unable to fart or poo, a high temperature or sudden confusion.
They load the knee differently, not dangerously: more behind the kneecap and on the ACL near straight, less with the knee well bent. They eased kneecap pain as well as squat-type exercise, didn't loosen the knee after ACL surgery, and knee arthritis care uses local muscle strengthening. With a sore knee, use the bent half of the range.
They grow three of the four muscles well, but the rectus femoris grew 1% with the leg press against 13% with leg extensions, and not at all with squats.
The NHS's own mini squat tells you to aim your knees over your big toe, and holding them back shifts the load to your hips and lower back, as our knee guide explains. With kneecap pain, limit it for a while, then build it back.
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Weak quads go with later knee arthritis (low-quality evidence) and predicted kneecap pain in military recruits, but in one study the arthritis link in women disappeared once body weight was accounted for, and hip and knee exercise eased kneecap pain without a measurable strength change. Strong quads help, but they're one part of the story.
Heavy training eased knee arthritis pain no more than light training over 18 months in 377 adults, though it built more strength.
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No position isolates it, as our knee guide explains, and hip and knee exercise together is the consensus treatment for kneecap pain. Train the whole quadriceps.
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We found no training trial of either for quad strength. They're useful holds, especially for tendon pain, and the Spanish squat put moderate load on the patellar tendon in a lab study, but holds were no better than ordinary lifting for patellar tendon pain in trials.
There isn't one. A squat or the leg press grows three of the four quad muscles, and the leg extension adds the rectus femoris, which grew 13% in 12 weeks with leg extensions against 1% with the leg press. A single-leg move such as split squats or step-ups adds balance and knee control.
Keep pain within our knee rule (0 to 2 out of 10 is fine, up to 5 if the knee settles by the next morning), and change depth and load rather than stopping. Sit-to-stands, step-ups, chair knee extensions and leg extensions in the bent half of the range let you control the load on the kneecap. Our knee strengthening guide has the full plan.
Not for healthy knees, and they're part of knee rehab. They load the knee differently from squats, more behind the kneecap near straight and less when the knee is well bent, and didn't loosen the knee in trials after ACL surgery.
Leg extensions, the leg press, step-ups, split squats, chair knee extensions, Spanish squats and reverse Nordics all load the quads. Leg extensions even reach the rectus femoris, which squats barely grow.
Sit-to-stands, wall sits, split squats, step-ups and step-downs, chair knee extensions with an ankle weight or band, and reverse Nordics need only a chair, a step and a wall. Our knee strengthening workout puts them in order.
Two or three times a week, 2 or 3 sets of 8 to 15 per move, with a day between. Guidelines ask for strength work on 2 or more days a week.
Weaker quads go with higher odds of painful knee arthritis later, about 1.4 to 1.9 times, but that's a link from low-quality evidence, not proof that strengthening prevents it. Exercise does ease knee arthritis pain, modestly.
Follow your physiotherapist's programme: quad strength drops by about 60% in the first month, mostly because the muscle won't switch on fully, and comes back with steady work. Heavier training was safe but no better for walking than standard rehab, and the evidence is low certainty. Our knee replacement guide has the stages.
In stages, as your rehab team sets them: one guideline starts leg extensions at about week 4, between 90 and 45 degrees of bend. Getting your quads close to the other leg's strength before sport went with fewer reinjuries, and our ACL surgery guide covers the stages.
No: no knee, hip or foot position isolates it. Train the whole quadriceps, and add hip work if your kneecap hurts, as the kneecap pain consensus recommends.
Strength rises within a few weeks, and the quad muscles grew by about 4 to 18% in 8 to 12-week trials. Knee pain changes more slowly and modestly: give it 12 weeks and keep going.
Sit-to-stands, chair knee extensions, step-ups and wall sits by a counter, then the leg press or leg extension in a gym. The NHS's strength exercises start sit-to-stands at 5 slow repetitions, and our exercise for older adults guide adds the balance work.
Exercise education, not a personal prescription, and clinical review of these guides is pending. Check with a GP before starting hard training if you have a heart condition, chest pain, dizziness or breathlessness when active, and stop for sharp or increasing pain. Health disclaimer.
