Are Squats Bad for Your Knees? What the Evidence Actually Says
For people with healthy knees, squats done with sensible technique and a gradually increasing load are not bad for your knees. The research on squatting, including deep squatting, has not shown that it damages healthy knee joints, and strengthening the muscles around the knee is widely recommended for keeping knees working well as you age. Problems tend to come from doing too much too soon, poor control under heavy load, or pushing through pain. If your knees already hurt, squats often still have a place, but the variation, depth and load need adjusting, and it is worth getting the knee checked first.
Where the fear comes from
A few ideas have shaped how people think about squats and knees:
- “Never let your knees go past your toes.” This rule spread widely from older research that measured forces at the knee. Restricting forward knee travel does reduce some knee load, but it shifts more stress to the hips and lower back, and for most people with normal proportions it is neither necessary nor natural.
- “Deep squats wreck your knees.” Deep squats change how load is shared across the knee, but there is no good evidence that they harm healthy knees when the load is appropriate. Many people squat to full depth every day in ordinary life.
- Someone you know hurt their knee squatting. Injuries do happen, as with any exercise. They usually involve too much load, too fast, or a movement that was already painful.
What squats actually do for your knees
The knee is supported by the thigh muscles, the hips and the calves. Squats train all of them. Stronger quadriceps and glutes help control the knee during everyday movements such as climbing stairs, getting up from low chairs and walking downhill. That is why strengthening exercises are a core part of the NHS advice on knee pain and why physiotherapists so often include squat-type movements in rehabilitation.
Technique that keeps knees comfortable
Good squat technique is less about one rule and more about control. These points matter most:
- Knees track in line with your toes. Let them move forward naturally, but avoid them collapsing inwards. Knees caving in when you squat covers the common causes.
- Whole foot on the floor. Weight spread across heel, big toe and little toe, not rolling onto the toes or the outside edges.
- Stance that suits you. Roughly shoulder width with toes turned slightly out is a good start, adjusted to your hips and ankles.
- Controlled descent. No dropping into the bottom and bouncing out.
- Depth you can control. Go as low as you can while keeping your back position and heels down. That depth often improves with practice.
How to squat properly goes into stance, depth and bracing in more detail.
Load: the factor people overlook
Most knee problems in the gym are load problems, not exercise problems. Tendons and joints adapt to training, but more slowly than muscles. If the weight, the number of sets or the frequency jumps quickly, the knee may complain. A few principles help:
- Increase one variable at a time: weight, or reps, or sets, not all three.
- Small jumps. Adding a little weight each week is plenty.
- Watch the total. Squats, lunges, running and stairs all load the knee; a big week of one deserves a lighter week of the others.
- Back off after a long break rather than resuming where you left off.
If your knees already ache
Knee discomfort does not automatically rule squats out, but it does change how you approach them. A sensible progression, ideally with guidance:
| Option | Why it helps |
|---|---|
| Box squat to a comfortable height | Controls depth and makes the descent predictable |
| Goblet squat | Lighter load held in front encourages upright, controlled movement |
| Split squat with short range | Loads one leg at a time and is easy to scale |
| Slower tempo | More control, less load needed for the same effort |
| Wider or narrower stance | Small changes can move discomfort away from the sore spot |
A useful rule of thumb many physiotherapists use is that mild discomfort during exercise can be acceptable if it settles quickly and is no worse the next day. Sharp pain, swelling, locking, the knee giving way, or pain that is worse the following morning are reasons to stop and get it assessed.
Check with your GP or a physiotherapist first if you have had a knee injury, surgery, ongoing swelling, or pain that is getting worse, and if you are returning to training after a long break.
Common mistakes that make knees grumble
- Skipping the warm-up. A few lighter sets let the joint and the movement settle before heavy work.
- Chasing a number. Adding weight while depth gets shallower and control worse.
- Bouncing out of the bottom under heavy load rather than controlling the turnaround.
- Squatting every day at high effort without planning recovery.
- Ignoring the hips and ankles. Stiff ankles or weak hips often push stress to the knee.
How squats are coached in the studio
In 1-1 personal training at the Highgate studio, most people start with goblet or box squats before a barbell goes anywhere near them. The studio has a squat rack, barbell and dumbbells, so the variation can be matched to how your knees respond that day, and progression is planned week by week rather than guessed. If a movement aggravates something, there is always another way to train the legs while it settles.
Questions we get asked
Is it bad if my knees go past my toes when I squat?
Not for most people. Forward knee travel is normal and shares the load more evenly. The priority is that knees track in line with your toes.
Are deep squats bad for your knees?
Not for healthy knees with appropriate loads. Go as deep as you can control while keeping good position.
Should I stop squatting if my knee clicks?
Painless clicking is common and usually harmless. Clicking with pain, swelling or locking should be checked.
What is the safest squat for beginners?
The goblet squat or a squat to a box. Both are easy to learn and simple to scale.
See how sessions are structured on the personal trainer in Highgate page, or start at The Highgate House homepage.
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