Many runners focus solely on pushing off the ground, but speed also comes from the ability to recruit the leg quickly: here is how to strengthen the hidden engine of your stride.
- Running with low knees limits stride length and makes you less efficient.
- The cause is often not technique, but a weakness in the hip flexors (iliopsoas).
- To run fast, pushing isn’t enough; you must know how to “pull” the leg up.
- Strengthening the psoas with specific drills (like the banded march) improves “Knee Drive.”
- Higher knees mean more flight time and greater speed at the same cadence.
Want a Bigger Stride? Stop Pushing and Start Pulling
Watch elite runners in slow motion. What do you notice immediately?
They have a massive stride length. And if you look closely, you’ll see their knees drive high, loaded with energy, ready to unleash power into the ground.
Now look at an amateur runner at Mile 20 of a marathon.
The knees barely lift, the feet seem to “shuffle” along the asphalt, and the run looks heavy.
The common mistake is thinking that to lengthen your stride, you need to push harder with your calves or swing your leg forward (causing dangerous overstriding).
The biomechanical explanation is different: to run well, you must lift the knee. If the knee doesn’t rise, the foot doesn’t have the time or space to land efficiently under your center of gravity.
The Secret Role of Hip Flexors in Speed
The protagonist of this movement is a deep and often overlooked muscle group: the hip flexors, captained by the famous iliopsoas.
We have already discussed this regarding mobility and how to unlock the hips, but today we are talking about strength.
The psoas is the only muscle that connects the spine to the legs. It is the “pulley” that, with every step, must lift the weight of your leg (which isn’t light!) to bring it forward.
If the psoas is weak, it tires quickly. When it tires, it stops pulling the knee up. The result? Your stride shortens, your cadence drops, and you slow down drastically, feeling like your legs are made of lead.
The Test: Are Your Hip Flexors Weak?
Do this quick test right now, standing up.
Lift one knee above hip height (so past 90 degrees). Now let go with your hands and try to keep the knee there, still, using only the strength of your leg.
Hold it for 10–15 seconds.
If the knee drops immediately, if you start shaking uncontrollably, or if you feel a painful cramp in your hip crease, I have news for you: your hip flexors are weak. And they are throttling your running potential.
3 Moves for Powerful Knee Drive
Fortunately, training “Knee Drive” is simple and yields fast results. Here are 3 exercises to add to your strength routine.
The Banded Psoas March
This is the king of exercises for runners.
How to do it: Stand up with a mini-band looped around your feet (right over your shoes).
Keep your body tall; lean against a wall if you need balance. Drive one knee toward your chest explosively, pulling against the band, until your thigh breaks parallel with the floor.
Lower with control.
Do 3 sets of 10–12 reps per leg.
Weighted Knee Raises
For the advanced runner, you need real load.
How to do it: You can use a low cable machine at the gym (using an ankle strap) or a kettlebell.
Standing on a raised surface (box or step), slip the toe of your foot through the handle of a light kettlebell (start with 8–12 lbs).
Drive the knee up, lifting the weight while keeping your foot dorsiflexed (toes up) to keep the kettlebell secure.
This exercise builds brutal strength in the flexors.
L-Sit Prep
A static hold derived from gymnastics.
How to do it: Sit on the floor with legs straight out in front of you. Place your hands on the floor beside your hips.
Without bending your knees and without leaning back, try to lift both heels off the ground (or one at a time to start).
You will feel the top of your quads and deep abs “on fire.” A few seconds of holding is enough.
Higher Knees = More Flight Time = More Speed
Working on your hip flexors isn’t about making you look like a 100-meter sprinter while jogging in the park.
It’s about making your running economical.
When the flexors are strong, leg recovery is quick and automatic. This creates more “flight time” without forcing you to bound, and allows the foot to land in the perfect position to push you forward again.
Less friction, more speed.