Hip flexor exercises: strength for knee drive, at the gym or at home

Your hip flexors are the muscles that lift your thigh toward your body: the knee coming up in a running stride, the leg rising in a leg raise. The main one sits deep, the iliopsoas (the psoas and the iliacus together), and a 2024 review calls it a primary hip flexor.¹ Another, the rectus femoris, runs down the front of the thigh. The authors of a 2005 trial note that hip flexion exercises are seldom emphasized in strength and conditioning for sports performance.²

This page is about strengthening them: the exercises, what the studies measured, what a few weeks of training did for sprinting and running, and where it fits in a week. Stretching the front of the hip is a different job, covered in hip mobility.

Why train them

• Sprint and agility tests. In a 2005 trial, 24 physically active but untrained people (13 men, 11 women) did eight weeks of hip flexion resistance training, and 24 others served as controls. The training group's hip flexion strength rose by 12.2%, their 40-yard dash times fell by 3.8% and their shuttle run times by 9.0%; the control group didn't improve.²
• Distance running. Eight well-trained male distance runners added hip flexor resistance training twice a week to their running for 12 weeks. Their psoas grew slightly on MRI, the time they could hold a set running speed went up, and the two changes were linked. All eight did the training; there was no comparison group.³
• A link with sprinting. In 10 young adults, hip flexion power, sprint performance and the size of the psoas were correlated.⁴ A link, not proof that one causes the other.

These are small studies, measured on sprint, agility and running tests. They show what changed for those groups, not what will change for you.

What the muscle-activity studies show

A 2024 review pulled together nine studies that measured iliopsoas activity with electrodes (EMG) during exercise, covering 109 healthy adults aged 20 to 40.¹ What it found, in practical terms:

• Lift the legs, not the trunk. Moving the legs toward the trunk, as in a leg raise or leg lowering, activated the iliopsoas more than moving the trunk toward the legs, as in a sit-up.¹
• The higher range counts. The iliopsoas was more active between 30 and 60 degrees of hip flexion, and above 60% of a maximal contraction in the straight leg raise around 60 degrees, in lying hip flexion and in leg lifts.¹ In a separate study of nine healthy men, psoas activity kept rising toward the top of a straight leg raise and was highest at the top and in the hold there, while the rectus femoris didn't keep rising.⁵
• Longer levers, both legs and added load make it harder. In leg raises, a straight leg (a longer lever) worked it harder than a bent one, lowering both legs harder than one, and every condition tested with added resistance increased the activity.¹

The review was written for rehabilitation exercise in a clinic. The activity readings are what this page uses; they're measurements during a single session, not changes over weeks.

The exercises

From easiest to hardest. The order follows the review's findings above (bent to straight legs, one leg to two, then added load); the sets and reps are practical.

The abs work on these too: in the straight-leg-raise study, the deep abdominal muscles were most active through the middle and top of the raise.⁵ Flutter kicks, V-ups and mountain climbers also lift the legs and fit as variety. Sit-ups involve the hip flexors too, though in the review, lifting the legs beat lifting the trunk.¹

A dose from a trial. The 12-week runner study used three hip flexor training regimens at a weight the runners could lift for at most 10 reps: 3 sets of 10 for the first four weeks, then 4 sets of 10, twice a week.³ That's a reasonable ceiling to build toward on the band, cable and hanging versions.

Stretching or strengthening?

They do different jobs. Strength work trains the hip flexors to lift the leg with force. Stretching trains range at the front of the hip, the position the back leg reaches in a lunge or a split squat, and has its own drills in hip mobility. One trial shows the difference: in 20 healthy people with limited hip extension, three weeks of hip flexor stretching at home increased hip extension on a passive test but didn't change how their hips and pelvis moved when they ran.⁶ If running or sprinting is the goal, the trials above used strength training.

Where it goes in your week

• Two days a week, matching the runner trial's frequency.³ Two or three exercises from the table at the end of a lower-body or core session takes about ten minutes.
• Before sprints, a set of standing knee raises or marches fits into the warm-up as a moving drill, like dynamic stretching. The hard sets go at the end of the session, not before it.
• Progress by moving down the table: straight legs, then both legs, then a band, cable or hanging version, adding reps before load. The sprint workout and how to run faster cover the running side.

This is training advice for healthy hips. If the front of a hip hurts, or you're coming back from a hip or back problem, a doctor or a physical therapist is the right first stop.

Common questions

What are the hip flexors?

The muscles that bring your thigh toward your body. The main one is the iliopsoas, deep in the hip, which the 2024 review calls a primary hip flexor;¹ the rectus femoris, on the front of the thigh, is another.

How do you strengthen hip flexors at home?

Standing knee raises, lying straight leg raises and two-leg lying leg raises need no equipment; a resistance band around your feet turns the knee raise into a loaded march. Progress through the table above.

Which hip flexor exercises suit runners?

The trials above don't name their exercises in their abstracts, so no study here picks one. Leg-lifting exercises with added resistance produced more activity in the review,¹ and, as a practical choice, the standing knee drive with a band or cable is the closest match to the running stride. Twice a week, alongside your running, is the frequency the runner trial used.³

Do sit-ups work the hip flexors?

Yes, though in the 2024 review, raising the legs activated the iliopsoas more than raising the trunk.¹ The sit-ups page has the details of what each version measured.

If you'd rather not plan it alone

Ten minutes of hip flexor work is easy to add once and easy to drop; fitting it next to your lifting and running without crowding either is the harder part. Coaching is the version where your program is written around the days you actually have, and a weekly call looks at your logbook and adjusts the plan. How coaching works explains it, and apply is the first step. Otherwise: at the end of your next two sessions this week, do two sets of the first two exercises in the table.