The 8 Exercises Trainers Never Recommend for Bad Knees
Aug 30, 2025 • 13 min read
Published on August 30, 2025 | Updated on August 30, 2025
August 30, 2025
NASM Personal Trainer, NASM Fitness Nutrition Specialist, ACE Sports Conditioning Specialist, NASM Performance Enhancement Specialist
Ask any good trainer, and they’ll tell you that some exercises simply aren’t worth the risk, especially if you’ve got bad knees.
Yet these same moves still show up in workouts all over the internet, at the gym, and even in group fitness classes.
The result? More pain, slower recovery, and knees that feel worse instead of better.
You don’t have to quit working out to protect your knees. You just have to stop doing the wrong exercises and swap them for smarter, joint-friendly alternatives.
With the right substitutions, you can keep building strength, improving mobility, and staying fit without punishing your joints in the process.
In this guide, we’ll reveal the exercises that seasoned trainers avoid for clients with knee issues, explain why they’re problematic, and give you safer swaps that work better for you.
Let’s dive into how you can work out without compromising your knees.
If you’re dealing with knee pain, it’s crucial to steer clear of movements that overload or destabilize the joint.
High-impact activities like running or jumping can stress the patellofemoral joint, which is where the kneecap meets the thigh bone. These sudden forces can cause discomfort and even worsen knee problems.
Research supports the idea that high-impact or deep-flexion exercises are linked to increased knee stress, especially in people with patellofemoral pain.
Studies have also shown that these types of movements can exacerbate existing knee problems, so it’s important to be cautious when choosing your workouts.
For example, deep knee bends, especially past a 90-degree angle, also add strain to your cartilage and ligaments.
Also, any move that puts your knee in a wobbly or unstable position can, additionally, increase the risk of injury.
A good rule of thumb is that if you’re feeling muscle fatigue, it’s a sign you’re working hard, but joint pain means it’s time to stop.
With that in mind, here are the 8 exercises to avoid if you have knee pain or you’re recovering from a knee injury.
We’ll also provide you with tweaks you can do if you normally enjoy the exercise but want to keep your knees safe.
Squats are often praised as a staple lower-body exercise.
But going too deep, especially past a 90-degree bend in the knee, can place excessive pressure on the cartilage, tendons, and ligaments that keep the joint stable.
This deep flexion increases the load on the patellofemoral joint and can cause the kneecap to press more firmly against the femur, aggravating existing issues like cartilage wear or inflammation.
For someone with knee pain, past injuries, or conditions such as arthritis, this strain can lead to sharp discomfort during the movement and may even accelerate joint degeneration over time.
The risk is even higher if the movement is performed with poor form, heavy weights, or rapid speed, all of which magnify stress on the joint.
A better approach is to stick to partial squats where your thighs lower to just above parallel to the floor.
You can also try wall sits to engage your quads and glutes without the same degree of knee flexion.
There’s also hip-dominant exercises like glute bridges or step-ups, which build lower-body strength while placing far less load on the knee joint.
Jumping lunges combine deep knee bending with an explosive push-off and landing, which creates high-impact forces on the joints.
Each repetition requires you to decelerate rapidly before switching legs midair, which sends a shock wave through the knees and demands precise control from the surrounding muscles.
For anyone with existing knee pain or instability, these sudden changes in direction can overload the patellofemoral joint, strain the ligaments, and irritate already sensitive cartilage.
The risk is even greater if your landing mechanics aren’t perfect or if fatigue sets in, since poor form during an explosive movement magnifies the stress on the knee joint.
The repeated impact and twisting can worsen pain, increase inflammation, and even contribute to overuse injuries.
Replace jumping lunges with reverse lunges or static split squats, which work the same muscle groups without the same degree of impact.
If you still want a cardio challenge, try adding a step-through at the top of the reverse lunge or using light dumbbells for resistance.
You’ll maintain intensity and strength gains while significantly reducing stress on the knees.
On the surface, leg extensions seem like a safe way to target the quadriceps, but performing them through a full range of motion, locking out at the top, can place excessive strain on the knee joint.
During this exercise, the resistance is applied at the ankle, which creates a long lever and increases the torque on the patellofemoral joint as you extend your leg.
This is particularly problematic when the knee is near full extension, where the joint structures are under maximum load.
For people with existing knee pain, cartilage damage, or conditions like patellar tendinitis, that torque can aggravate symptoms, cause sharp discomfort, and potentially accelerate wear in the joint.
The movement also isolates the quads without engaging the hamstrings or glutes, meaning the knee is being loaded without the natural co-contraction of stabilizing muscles that help distribute force.
Swap full-range leg extensions for terminal knee extensions (TKEs) using a resistance band, which strengthen the quads while allowing a more controlled range of motion and less torque at the joint.
Step-ups are generally a great functional exercise for strengthening the lower body, but adding a jump at the top changes the movement from controlled strength training to a high-impact plyometric drill.
The force generated when landing can send a jolt through the knees, challenging their ability to absorb shock.
This impact is magnified if you land stiff-legged or lose balance on the way down, which can quickly overload the joint structures.
The dynamic shift from stepping up to launching into a jump also creates a sudden demand for stability.
If your hip, knee, and ankle are not perfectly aligned during takeoff or landing, the knee can be forced into awkward positions that strain ligaments and surrounding tissues.
Keep the step-up but remove the jump to maintain its strength benefits without the risky landing impact.
Focus on driving through your heel to activate the glutes and keep the knee tracking over the toes.
Lateral lunges can be a useful way to train side-to-side movement, but taking them too deep can place excessive strain on the knee’s ligaments and supporting tissues.
The wide stance and deep bend create a high degree of lateral force on the joint, which can stress the medial collateral ligament (MCL) and overload the cartilage, particularly if the knee collapses inward.
The movement also demands strong hip mobility and balance. Without both, your body may compensate by twisting the knee or shifting weight awkwardly, further increasing injury risk.
Limit the range of motion to a comfortable depth, stopping well before the point of discomfort, or replace deep lateral lunges with side-lying leg lifts or standing lateral band walks.
These alternatives strengthen the glutes, hips, and outer thighs while keeping the knee in a safer, more stable position.
As strength and mobility improve, you can gradually reintroduce controlled, shallow lateral lunges to restore side-to-side movement without overloading the joint.
Box jumps are a staple in explosive training, but the landing phase is where most of the risk lies.
Dropping from a height creates a large impact force that travels up through the ankles, knees, and hips.
If the landing mechanics are off, that force can hit the knee joint directly, stressing the ligaments, cartilage, and patellofemoral joint.
The danger increases if you land with locked knees, collapse inward, or absorb the impact unevenly between legs.
Fatigue, poor foot placement, or an unstable landing surface can make these problems more likely.
Even if your form is perfect, repeated high-impact landings can cause cumulative strain, leading to irritation, swelling, or overuse injuries.
Swap high-impact landings for low-impact step-downs or box step-ups with a powerful drive through the heel.
Running stairs at full speed may seem like a great cardio and leg workout, but the aggressive pace and repeated impact can be tough on the knees.
Each upward drive pushes the knee into a deep bend under load, while the downward run magnifies impact forces as you land on each step.
The risk climbs even higher when fatigue sets in, as form often breaks down.
Landing heavily, letting the knees cave inward, or missing a step can all add unwanted torque or strain to the joint.
Even in healthy knees, the repetitive pounding can take its toll over time, making this a risky choice for anyone prone to knee issues.
Trade high-impact stair sprints for slow, controlled stair climbs or step-ups at a moderate pace, focusing on smooth movement and proper alignment.
If cardio intensity is your goal, try low-impact intervals like cycling or incline walking, which raise your heart rate without the same repetitive stress on your knees.
Burpees are a demanding full-body exercise, but their fast, explosive nature can be unforgiving on sensitive knees.
The combination of jumping up from the squat position and quickly dropping back down places the knee under repeated compression and impact.
Each landing from the jump sends force directly through the lower body, and if your form slips, the knees can absorb more stress than the surrounding muscles.
The rapid transition between positions also challenges stability. If the knees cave inward during the squat phase or the landing is heavy and uncontrolled, the risk of irritation or strain increases significantly.
Replace high-impact burpees with low-impact burpee variations that remove the jump.
Step back into the plank instead of hopping, and step forward into the squat before standing tall.
This keeps the full-body training benefits while drastically reducing the landing forces that can aggravate your knees.
Staying active with knee pain doesn’t mean you have to give up on building strength.
In fact, there are plenty of knee-friendly exercises that can be just as effective for strengthening your muscles without putting extra stress on your joints.
Remember: if you feel sharp pain at any point, stop immediately, and assess your movement.
Here are some alternatives that focus on building strength while keeping your knees safe:
A safer alternative to deep squats, hip thrusts target the glutes and hamstrings without deep knee flexion, reducing stress on the knees.
How to Do It:
Sit with your upper back on a bench, knees bent, feet flat and hip-width apart.
Brace your core, then push through your heels to lift your hips until your body forms a straight line from shoulders to knees.
Squeeze your glutes at the top, then lower your hips slowly.
Repeat for 8–12 controlled reps.
Tip: Once bodyweight feels easy, place a dumbbell or barbell across your hips for added resistance.
Check out this guide for more glute exercises with bad knees.
A great alternative to deep squats, Romanian deadlifts target the hamstrings, glutes, and lower back without forcing deep knee flexion.
How to Do It:
Stand tall with feet hip-width apart, holding a barbell, dumbbells, or no weight at all.
Keep a slight bend in your knees and hinge forward at the hips, pushing them back while keeping your spine neutral.
Lower until you feel a stretch in your hamstrings, then drive your hips forward to return to standing.
Repeat for 8–12 controlled reps.
Tip: Try single-leg or resistance band variations for added challenge without increasing knee stress.
A knee-friendly alternative to jumping lunges, this static hold builds lower-body strength and stability without the jarring forces of explosive movements.
How to Do It:
Stand with feet shoulder-width apart and lower into a comfortable squat position, keeping knees over your toes.
Engage your core, keep your chest tall, and hold the position without bouncing.
Maintain even pressure through your heels and midfoot.
Hold for 20–45 seconds, rest, and repeat for 3–4 sets.
Tip: For extra challenge, hold a light weight at chest height or add a resistance band around your thighs.
A safer alternative to full-range leg extensions, seated knee extensions strengthen the quadriceps without placing excessive torque on the knee joint.
How to Do It:
Sit tall in a sturdy chair with feet flat on the floor.
Slowly extend one leg until it’s almost straight, keeping a slight bend in the knee.
Hold for 1–2 seconds, then lower back down with control.
Perform 10–15 reps per leg for 2–3 sets.
Tip: For added resistance, loop a light ankle weight or resistance band around your ankle.
For more exercises for quads with bad knees, check out this guide.
A safer alternative to high box step-ups, step-backs reduce strain on the patellofemoral joint by avoiding the deep knee bend and high impact of stepping onto an elevated surface.
How to Do It:
Stand tall with feet hip-width apart and arms raised overhead.
Step one foot straight back, keeping your front knee aligned over your ankle.
Push through your front heel to return to the starting position.
Alternate legs for 10–12 reps per side, 2–3 sets.
Tip: Focus on keeping your core engaged and your front knee stable to get the most from this knee-friendly move.
A hip-dominant alternative to deep lateral lunges, this move reduces knee strain while strengthening the glutes, hamstrings, and lower back.
How to Do It:
Stand with feet hip-width apart, arms extended in front of you.
Keep a slight bend in your knees and hinge forward at the hips, pushing them back as you reach your arms forward.
Lower until you feel a stretch in your hamstrings, then return to standing by driving your hips forward.
Perform 10–12 reps for 2–3 sets.
Tip: Keep your back flat and core engaged to protect your spine and maintain balance.
A low-impact alternative to burpees, this move delivers a full-body workout and cardio challenge without the harsh landing forces that can aggravate knee pain.
How to Do It:
Start in a high plank with your hands under your shoulders and core engaged.
Step your right foot forward to the outside of your right hand, keeping your back leg straight.
Step back to the plank position, then repeat with the left leg.
Alternate legs at a steady pace for 20–40 seconds, resting between rounds.
Tip: Keep movements controlled and hips level to protect your knees and maintain proper form.
Do you need more burpee alternatives? Check out this guide.
A knee-friendly alternative to lateral lunges, reverse lunges reduce side-to-side stress on the joint while still strengthening the quads, glutes, and hamstrings.
How to Do It:
Stand tall with feet hip-width apart.
Step one foot straight back, lowering your hips until both knees are bent about 90 degrees.
Keep your front knee aligned over your ankle and your chest tall.
Push through your front heel to return to the starting position.
Perform 8–12 reps per side for 2–3 sets.
Tip: Hold light dumbbells at your sides for added resistance without increasing knee strain.
It’s natural to wonder if replacing deep squats or lunges with knee-friendly options will hold back your progress.
Just remember: the key to results isn’t necessarily the specific exercise, but rather how you train.
Progressive overload—steadily increasing the difficulty—works with any movement, whether it’s a squat, glute bridge, or step-up.
In truth, knee-friendly exercises often improve muscle control and isolation, enhancing strength and stability.
Plus, taking care of your joints reduces injury risk and helps you stay consistent.
With the right mindset and gradual progression, alternative exercises can lead to safe, lasting progress.
Staying active with knee pain is possible: it's all about making smart exercise choices.
By swapping high-impact, knee-stressing movements for safer alternatives, you can continue building strength and staying fit without exacerbating joint issues.
Just don’t forget to listen to your body, stop if you feel sharp pain, and focus on exercises that support your knees.
With the right approach, you can keep progressing without sacrificing your health.
Before swapping out any exercises, it’s worth clearing up some common misunderstandings about training with knee pain.
This section answers key questions about which movements to avoid, which ones to choose instead, and how to make adjustments so you can keep building strength and fitness without setting your knees back.
Yes, you can still build muscle with knee pain by focusing on knee-safe exercises that reduce joint stress.
Movements like hip thrusts, Romanian deadlifts, and step-back lunges target the same muscle groups without aggravating knee issues.
Always listen to your body and stop if you feel sharp pain or discomfort.
If you feel sharp or intense knee pain during any exercise, stop immediately and reassess your form.
It’s important to avoid pushing through joint pain, as this could lead to further injury.
If the pain keeps bothering you, check in with a healthcare professional or a physical therapist.
Seated knee extensions are a gentle way to strengthen the quadriceps without putting excessive stress on the knee.
This exercise allows you to work the muscles in a controlled manner, avoiding the deep knee bends that could lead to strain.
Always focus on slow, controlled movements for safety.
This article is intended for general informational purposes only and does not address individual circumstances. It is not a substitute for professional advice or help and should not be relied on to make decisions of any kind. Any action you take upon the information presented in this article is strictly at your own risk and responsibility!
