How to do the splits: which muscles limit them, what the studies measured, and a practical routine

The splits mean your legs apart to a straight line on the floor, either front-and-back (the front split) or out to the sides (the middle split). They ask mostly for range at the hips, though holding one without support also takes strength and control, which is a practical point and not something the studies below measured. Stretching is the tool those studies test for range.

The studies on this page measured the angle of a hip or the length of a muscle before and after stretching, not whether a person reached the splits, so they can't give you a date. What they can give you is the dose: what kind of stretching, how long a hold, how many days, and what a trial of the hip flexors and a trial of the inner thighs actually found. This page covers which muscles limit each split, what the studies measured, a practical routine, and the questions people ask. A general full-body routine is on the stretching routine, and flexibility for lifting is on the hip mobility page.

What limits each split

This is a practical reading of the anatomy, not a study finding: the two splits stretch different muscles.

Whichever one feels tighter for you is where to spend your minutes.

What the studies measured

• Stretching for weeks adds range. The 2024 meta-analysis of 77 studies found stretching programs of at least two weeks increased range of motion with a moderate effect compared with not stretching. Static holds and PNF stretching did better than ballistic or dynamic stretching, and the amount, intensity and frequency of stretching didn't play a significant role in how much range people gained.¹
• The hip flexors, six weeks. In 23 healthy adults screened for tight hip flexors (15 women and 8 men, about 24 years old), a group that did a lunge-and-reach stretch daily, five 30-second holds per leg, for six weeks gained about 5.9 degrees of hip extension on a standard test, against 2.6 degrees in the no-stretching group. The difference between the groups was 3.3 degrees.² It was a small trial. The control group did no stretching, and nothing in the paper says it was told to stop its regular exercise. Compliance in the stretching group was self-reported at about 79 percent.
• The inner thighs, one session. In 40 healthy, active adults aged 18 to 35 who had limited hip abduction range, each person did three conditions on separate days in a crossover design: a single 60-second passive stretch on a machine, a single 60-second active stretch (a weight-bearing position, with the opposing muscles holding it), and a time-matched control. Seated hip abduction improved by 1.0 degree after the passive stretch and 1.2 after the active one. The control condition gained 0.6 degrees, and the three conditions did not differ from one another.³ The same study found no loss of adductor strength after either stretch.³ One short session is a different thing from the weeks above.
• The hamstrings. In 93 adults aged 21 to 39 with limited hamstring flexibility, four groups stretched for 30 or 60 seconds, once or three times a day, five days a week for six weeks, and all of them gained more knee-extension range than a non-stretching control. Longer holds or more frequent stretching added no further gain, and the authors conclude that a 30-second hold is an effective duration.⁴

Those results don't line up as one tidy story, and they weren't designed to: they used different muscles, tests and people. The two trials that followed people for six weeks with regular holds, and compared them with a group that didn't stretch, both found more range in the stretching groups.

How much stretching the guidelines point to

• The guideline floor. The American College of Sports Medicine recommends flexibility exercises for each major muscle-tendon group, a total of 60 seconds per exercise, on two or more days a week.⁵
• The consensus panel's range. A 2025 panel of stretching researchers recommends 2 to 3 sets a day, each held 30 to 120 seconds per muscle, to reach the highest possible weekly volume.⁶
• The 2018 review. A review of 23 studies found that the time spent stretching per week mattered more than the time in any one session, with gains once weekly stretching reached at least five minutes, and that more days a week went with more range.⁷

These point the same way: regular, repeated holds. They don't agree on a single number, and the 2024 meta-analysis found no significant effect of volume, intensity or frequency,¹ so use them as a range and not a prescription.

A practical routine

This is a practical plan built on the dose lines above, not a protocol any of the studies tested. Do it after training or on a separate day (see the question on timing below), five days a week, about ten minutes:

1. Lying hamstring stretch (front split, front leg): on your back, a towel or band around one foot, the leg raised with the knee nearly straight. Two holds of 30 seconds a side.
2. Lunge-and-reach (front split, back leg): the dose from the six-week trial. In a half-kneeling lunge, lean forward and reach one arm overhead toward the opposite side. Five holds of 30 seconds per leg in that trial; start with two or three and build up.²
3. Frog stretch (middle split): on hands and knees, knees wide, feet turned out, and rock your hips back toward your heels. Two holds of 30 to 60 seconds. The active stretch in the adductor study was described as similar to a frog straddle.³
4. Seated straddle (middle split): sit with your legs wide and straight, back tall, and fold forward from the hips. Two holds of 30 seconds.

Hold each stretch where you feel a clear pull, not pain, and breathe slowly. If a stretch hurts rather than pulls, stop; I'm a fitness coach, not a doctor, so that's a question for a doctor or a physical therapist. Keep the holds still: the 2024 meta-analysis found static and PNF stretching did better than bouncing or swinging.¹ Track the angle once a week, in the same position, rather than looking for a daily change.

Keeping the range you gain

A 2025 meta-analysis of 13 studies (556 people, aged about 6 to 66) followed stretching programs of 5 to 15 weeks with 2 to 6 weeks off. Range stayed above where people started, but dropped a little from where they finished.⁸ In practice, that means a few holds a week after you reach a goal is a reasonable plan, which is a practical reading and not a finding.

Common questions

How long does it take to do the splits?

The studies cited here measured range in degrees after one session or after weeks of stretching; none measured whether anyone reached the splits, so I won't give a number of days. The one-session adductor study found a change of about 1 degree, which did not differ from its control's.³ The six-week trials are the ones that found a clearer gain.^2,4

How long should you hold a stretch for the splits?

The guideline is 60 seconds in total per muscle group, which two 30-second holds cover.⁵ In the six-week hamstring trial, stretching for 30 or 60 seconds, once or three times a day, gave similar gains, and the authors conclude that 30 seconds is an effective hold.⁴ The consensus panel's range is higher, 30 to 120 seconds per muscle, 2 to 3 sets a day.⁶

Should I stretch before or after training?

In a 2016 review, static stretching lowered performance by about 4 percent on average when people were tested a few minutes later, and longer holds of 60 seconds or more per muscle group lowered it more.⁹ For lifting days, do the moving warm-up first (the lifting warm-up and dynamic stretching cover it) and keep the long holds for after or for another time of day.

Do I need to do both splits?

No. They load different muscles, so pick the one you want, or work on both at different times in the week.

Is this a stretching routine or a mobility routine?

It is a flexibility routine for one goal. Range for squatting, hinging and pressing is on the mobility routine, and touching your toes is the hamstring-focused version of this page.

If you want it built into a plan

Ten minutes of stretching five days a week is simple to plan and easy to drop the first busy week. If you want flexibility in a plan next to your strength and cardio, that's what I build in coaching: the workouts sit in the Trainerize app, and every week we get on a call, look at what happened, and I set up the next week. Coaching for beginners explains how it works, and you can apply here. Otherwise: pick one split, do the matching stretch tonight, and write down how you felt at the end of the hold.