The single best thing you can do to protect your knees on the slopes is build strength in the muscles that surround and stabilize the knee joint, starting at least six weeks before your first day on snow. Skiing places enormous force on your knees during every turn, bump, and stop, and the joint itself relies almost entirely on muscles and ligaments to stay stable. A targeted program that strengthens your quadriceps, hamstrings, glutes, and core can cut your risk of a serious knee injury nearly in half.
Why Skiing Is So Hard on Knees
The knee is the most commonly injured joint in skiing, and the anterior cruciate ligament (ACL) takes the worst of it. One well-studied mechanism, called the “phantom foot,” happens when a skier falls backward into a sitting position and the inside edge of the ski tail catches the snow. This forces the shinbone to rotate inward while the rest of the body keeps moving, putting extreme twisting force on the ACL. It can happen in a fraction of a second, often without any contact or collision.
High-speed carved turns also load the knee in ways that everyday life doesn’t prepare you for. Your quadriceps absorb repeated eccentric contractions (lengthening under load) as you control your speed, while your hip and glute muscles work constantly to keep your knees from collapsing inward. If any link in that chain is weak or fatigues early, the knee becomes vulnerable.
Start Training at Least Six Weeks Out
Six weeks is the minimum lead time to make meaningful strength and stability gains before ski season. That’s enough to wake up underconditioned legs, build muscular endurance, and improve the neuromuscular control that keeps your joints aligned under load. Aim for three strength sessions per week if possible, but start with whatever you can realistically commit to and build from there.
If you begin earlier, eight to twelve weeks out, you’ll have time to progress through heavier loads and more advanced exercises. But six weeks of consistent work is far better than a longer plan you abandon after two weeks.
Build Quad and Hamstring Strength
Your quadriceps are the primary shock absorbers in skiing. Every time you flex into a turn or absorb a mogul, your quads are lengthening under heavy load. Building eccentric quad strength (the ability to control a muscle as it lengthens) is especially important because that mirrors exactly what skiing demands.
Double-leg squats are the foundation. Start with one set of 10 repetitions, holding each squat for five seconds at the bottom. Over the weeks, work up to 30 reps with 15-second holds. That progression builds the deep muscular endurance your legs need for long runs. Single-leg squats are the next step: start with five on each leg and repeat as many sets as you can with good control. These expose and correct side-to-side imbalances that double-leg exercises can mask.
Lunges and Bulgarian split squats add a dynamic, sport-specific element. Begin with one set of five per leg and increase volume as your control improves. Step-ups on a box or bench are another excellent option, since they closely mimic the quad-dominant loading pattern of skiing. In all of these exercises, focus on a slow, controlled lowering phase. That eccentric portion is where the protective strength is built.
Your hamstrings matter just as much, even though they’re easier to overlook. Strong hamstrings act as a direct counterbalance to forces that pull the shinbone forward, which is exactly the motion that tears the ACL. Research on alpine ski racers shows that a healthy ratio of hamstring-to-quadriceps strength is a key marker of knee protection. Women who demonstrated greater relative hamstring activation showed signs of enhanced ACL protection compared to their peers. Gluteal bridges are a simple way to target the hamstrings and glutes together: start with one set of 10, holding each bridge for five seconds, and add reps as you get stronger.
Don’t Ignore Your Hips
Knee injuries in skiing rarely start at the knee. When the muscles on the outside of your hip (particularly the gluteus medius) are weak, your thighbone tends to rotate inward during dynamic movements, pulling the knee into a collapsed, inward position called valgus. This position puts the ACL and other ligaments under dangerous stress.
Eccentric hip abductor training, where you focus on controlling the lowering phase of a side-stepping or lateral movement, is particularly effective. A recent study found that eccentric hip abduction training was superior to traditional concentric training at reducing that inward knee collapse during jumping tasks. For skiers, this translates directly to better knee alignment during aggressive turns and landings.
Crab walks (also called monster walks) are one of the simplest ways to train hip abduction. Place a resistance band around your ankles or just above your knees and take small steps sideways in a half-squat position. Five sets of eight steps is a good starting point. Lateral lunges and side-lying leg raises are useful additions once the band walks feel easy.
Add Plyometrics for Reactive Control
Strength alone isn’t enough. Skiing requires your muscles to fire quickly and reflexively in response to changing terrain. Plyometric exercises train that reactive ability by combining speed, power, and coordination.
Start with basic two-leg exercises: squat jumps, box jumps, and lateral hops (side to side). Focus on landing softly with your knees tracking over your toes, not collapsing inward. Begin with one set of 8 to 10 landings with equal weight on each leg, and build up to 20 to 24 well-controlled landings per session.
As you progress, move to single-leg plyometrics. Ski hops (jumping laterally from one foot to the other, mimicking a slalom motion) are among the most ski-specific exercises you can do. Jumping lunges, single-leg hops through an agility ladder, and single-leg hurdle bounds all build the kind of explosive, asymmetric control that skiing demands. Only advance to these once your landing mechanics are solid on two legs.
Train Balance and Proprioception
Proprioception is your body’s ability to sense where your joints are in space and correct their position without conscious thought. It’s what keeps your knee stable when you hit an unexpected patch of ice or a rut in the snow. And training it produces real results: a two-year prevention program with adolescent competitive skiers that combined neuromuscular control exercises with core stability work reduced ACL injuries by 45%, dropping the injury rate from 8.1% to 3.9%.
The exercises don’t need to be complicated. Single-leg balance holds on an unstable surface (a foam pad, a wobble board, or even a folded towel) are a good starting point. Progress to single-leg squats on the same unstable surface once you’re comfortable. The single-leg hop for distance and the square hop test (hopping in a square pattern on one foot) were both used in the program that achieved that 45% reduction. On-snow drills like skiing with the inside ski lifted also build proprioceptive control in sport-specific positions.
Core Stability Ties It All Together
Your core connects your upper and lower body and transmits force between them during every turn. A weak core means your legs have to compensate, which accelerates fatigue and leaves your knees exposed. Planks and side planks are the simplest effective core exercises for skiers. Start by holding each for 10 to 20 seconds and gradually build to one minute. Side planks are especially valuable because they activate the lateral stabilizers that resist the rotational forces of skiing.
What About Knee Braces?
If you’ve never had a knee injury, the evidence for wearing a prophylactic knee brace is thin. Most research on preventive braces comes from contact sports like football, and even there, the data only supports some protection against medial collateral ligament (MCL) injuries, not ACL tears. There are no strong clinical studies specifically evaluating preventive braces in healthy skiers. A brace may offer some benefit, but it’s not a substitute for the muscular strength and neuromuscular control that actually keep the joint stable under load.
If you have a history of knee injury, particularly a prior ACL reconstruction, a functional knee brace fitted by a specialist is a different conversation and may be worthwhile alongside your training program.
A Simple Weekly Framework
Three sessions per week, each lasting 30 to 45 minutes, is enough to make meaningful progress. A practical session might look like this:
- Strength (15 to 20 minutes): Double-leg squats, single-leg squats or Bulgarian split squats, lunges, gluteal bridges, and crab walks with a resistance band.
- Plyometrics (10 minutes): Squat jumps, lateral hops, and ski hops. Focus on quality landings over volume.
- Balance and core (10 minutes): Single-leg balance holds on an unstable surface, planks, and side planks.
Progress by adding reps, hold times, or load each week. Move from double-leg to single-leg variations as your control improves. By week six, your legs should feel noticeably more resilient, your balance sharper, and your first days on snow far less punishing on your knees.