High knees are a bodyweight cardio exercise where you jog in place while driving each knee up to roughly hip height. The movement combines the leg action of sprinting with the arm pumping of a full run, all without needing any equipment or forward space. It’s one of the most common exercises you’ll see in warm-ups, HIIT circuits, and sports training because it simultaneously raises your heart rate, strengthens your lower body, and reinforces the running mechanics that carry over to athletic performance.
How the Exercise Works
The basic motion is straightforward: you stand tall, then alternately drive one knee up toward your chest while the opposite foot stays on the ground. Your arms swing in coordination, just like they would during a sprint. The faster you cycle your legs, the more demanding the exercise becomes for both your cardiovascular system and your muscles.
What makes high knees effective is how many muscle groups fire at once. Your hip flexors do the heavy lifting to drive each knee upward. Your quadriceps extend the supporting leg and help control the landing. Your glutes and hamstrings engage on the standing side to keep you stable and upright. Your calves absorb impact and push off the ground with each step. Meanwhile, your deep core muscles (the ones wrapping around your midsection like a belt) work constantly to keep your torso from leaning or rotating. Even your biceps and triceps contribute as you pump your arms.
How to Do High Knees With Good Form
Start by standing with your feet hip-width apart and your arms at your sides. Begin by driving your right knee up until your thigh is parallel to the floor, or as close to that as you can manage. At the same time, swing your left arm forward naturally. As you lower your right foot, immediately drive your left knee up while your right arm swings forward. The rhythm should feel like an exaggerated jog in place.
A few cues that make a real difference:
- Stay tall through your spine. A common instinct is to lean forward or hunch your shoulders as you fatigue. Keep your chest lifted and your gaze straight ahead. This protects your lower back and forces your core to do its job.
- Land on the balls of your feet. Avoid slamming your heels into the ground. A soft, springy landing with slightly bent knees spreads impact across multiple joints and reduces pressure on your knees.
- Drive the knee, not just the foot. Think about pushing each knee toward the ceiling rather than just lifting your foot off the ground. This engages the hip flexors more fully and builds the range of motion that translates to better running form.
- Pump your arms with purpose. Your arms aren’t just along for the ride. Active arm swings generate momentum, increase calorie burn, and help you maintain a faster tempo.
Calories Burned and Cardio Benefits
High knees fall into the category of high-intensity functional training, which research shows burns roughly 10 to 11 calories per minute during the working segments. That puts a focused 10-minute bout in the range of 100 to 110 calories, though the exact number depends on your body weight and effort level. The metabolic demand of exercises like high knees ranges from about 7 to 15 METs during intense work periods, meaning they require 7 to 15 times the energy your body uses at rest. For comparison, brisk walking sits around 3 to 4 METs. That intensity is what makes high knees so efficient for improving cardiovascular fitness in a short window of time.
Because the exercise spikes your heart rate quickly, it’s a natural fit for interval-style training. A typical approach is 20 to 30 seconds of high knees followed by 10 to 15 seconds of rest, repeated for several rounds. Even three to four minutes of this pattern can serve as a potent warm-up or a standalone cardio burst between strength exercises.
Why Athletes Use High Knees
High knees aren’t just a cardio drill. They specifically train the neuromuscular patterns involved in sprinting. Each rep reinforces the rapid hip flexion and knee drive that generate stride power. Research on stride frequency manipulation shows that training at faster-than-normal leg turnover rates increases activation in the muscles along the front and back of the thigh and the front of the shin. This is exactly what high knees simulate: a faster-than-normal knee drive that teaches your nervous system to fire those muscles more quickly and efficiently.
That’s why you’ll see sprinters, soccer players, and basketball athletes doing high knees as part of their pre-practice routine. The drill primes the connection between brain and muscle before explosive activity begins, and over time it helps develop the hip flexor strength and range of motion that contribute to longer, more powerful strides.
Easier and Harder Variations
If standard high knees feel too intense or you’re working around joint sensitivity, marching in place is the simplest modification. You perform the same knee-drive motion but at walking speed, keeping one foot on the ground at all times. This eliminates the impact of both feet leaving the ground and keeps the movement low-impact while still training hip flexor strength and coordination.
To progress the exercise, you have several options. Adding a brief pause at the top of each knee drive (holding your thigh parallel to the floor for a full second) increases the demand on your hip flexors and core. Moving forward instead of staying in place turns the drill into a traveling high-knee run, which adds a coordination challenge and covers more ground. For maximum intensity, you can combine high knees with a resistance band looped just above the knees, which forces your hip flexors to work harder against the band’s pull on every rep.
Common Mistakes That Lead to Pain
The most frequent error is leaning your torso too far forward. When your chest drops, your lower back compensates by arching, which can strain the muscles along your spine over repeated reps. If you notice yourself hunching, slow down. Speed is not worth sacrificing posture.
Landing with stiff, straight legs is another problem. Each foot strike sends force through your ankle, knee, and hip. When you land with a slight bend in your knee and on the ball of your foot, that force gets absorbed gradually across the whole chain. Landing flat-footed or with locked knees concentrates the impact in a way that can irritate joints over time. Think of your legs as springs, not stilts.
Finally, many people sacrifice knee height as they fatigue, turning the exercise into a fast shuffle. Once your knees stop reaching hip height, you’ve lost most of the hip flexor and core benefit. It’s better to slow your tempo and maintain full range of motion than to speed up with half-effort reps.
Who Should Modify or Skip High Knees
High knees involve repetitive impact and rapid knee flexion, which makes them a poor fit for certain situations. If you’re dealing with a knee arthritis flare-up, the combination of pressure from landing and the repeated bending motion can aggravate an already inflamed joint. During active flare-ups, the goal is to reduce pressure and friction on the knee, which means swapping high knees for a low-impact alternative like cycling or marching in place.
People recovering from hip flexor strains, shin splints, or stress fractures in the lower leg should also hold off. The rapid, repetitive loading that makes high knees effective for conditioning is the same loading pattern that aggravates these injuries. Once you’re pain-free through a full range of motion at walking speed, you can begin reintroducing the exercise at a slow march and gradually increase tempo over several sessions.