Core Workouts for Runners

What the evidence says

Core training for runners is recommended everywhere, usually with the claim that it improves running economy and therefore performance. The evidence for that specific claim is mixed, and it’s worth saying so before prescribing anything.

Some studies find benefits. An eight-week randomized study of core training¹ found significant improvements in core endurance and sport-specific endurance measures, along with lower heart rates during the early stages of a treadmill test. Others find nothing. A six-week core training study² showed no significant improvement in maximal oxygen uptake (VO₂ max), running economy or running posture, though it did find improved 5000m performance without a corresponding change in running kinetics.

A fair summary is that core training reliably improves core measures, sometimes improves performance, and has an unclear and inconsistent effect on running economy specifically.

The stronger case for trunk work has little to do with economy. Running is a single-leg activity performed thousands of times, and controlling the pelvis during single-leg stance keeps load off the structures that commonly fail. It’s the same argument that makes hip strength the best-evidenced intervention for runner’s knee.

There’s also a suggestive finding on fatigue. A randomized crossover trial³ found that trunk and upper body fatigue adversely affects running economy, which implies the useful quality is trunk endurance, the ability to hold position late in a run, rather than trunk strength in the gym sense.

What “core” should mean here

For a runner, the core isn’t the abdominal muscles you can see. A more useful definition is everything that controls the position of the pelvis and ribcage relative to each other: the deep abdominals, obliques, spinal erectors and, critically, the glutes.

The job during running is almost entirely resisting movement, not producing it. With each stride your trunk resists rotation from the opposing arm and leg, resists side-bending as the pelvis is loaded on one leg, and resists extension as the hip drives back. None of that resembles a sit-up.

That’s why crunches are close to useless for runners. They train trunk flexion, a movement running never asks for, lying down, for short durations and with no single-leg demand, so almost every variable is wrong.

The routine

Twice a week, roughly 15 minutes. Do it on non-running days or after an easy run. Quality of position matters far more than repetitions; if your form collapses, the set is over.

Front plank, 3 × 30–45 seconds. Straight line from heel to head, ribs down, glutes squeezed. Don’t chase long holds, because a rock-solid 40 seconds is worth more than a sagging three minutes. Progress by lifting one foot an inch or two (a few centimeters) for 5 seconds at a time.

Side plank, 3 × 20–30 seconds per side. This is the most directly relevant plank for runners, because it loads the lateral chain that resists pelvic drop in single-leg stance. Progress by adding a top-leg lift.

Dead bug, 3 × 8 per side. On your back, arms up, knees over hips. Lower the opposite arm and leg slowly while keeping your lower back flat to the floor. If your back arches you’ve gone past your control, so shorten the range. This trains anti-extension, which is exactly what fails when runners get tired and start over-arching.

Bird dog, 3 × 8 per side. On hands and knees, extend opposite arm and leg without letting the hips rotate. Balance a water bottle on your lower back if you want objective feedback.

Pallof press, 3 × 10 per side. With a resistance band anchored at chest height beside you, press the band straight out and resist the rotation it applies. It’s the purest anti-rotation exercise available and the closest single movement to what your trunk does when running.

Single-leg glute bridge, 3 × 10 per side. The glutes are functionally part of this system, and pelvic control in single-leg stance is the whole point of the routine.

Progress by endurance, not load

Since trunk fatigue is what degrades running mechanics, the sensible progression is toward holding good position for longer and under more instability, rather than toward heavier resistance.

In order of usefulness:

1. Improve the quality of the position first. Most people’s plank is worse than they think.
2. Extend the duration modestly: 30 to 45 seconds, not 30 seconds to five minutes.
3. Reduce the base of support by lifting a foot, lifting a hand, or moving to single-leg variants.
4. Add movement while holding position. This is where dead bugs and Pallof presses earn their place.

How to tell if your plank is any good

A bad plank trains the exact compensations you’re trying to eliminate. These are the four common faults, from most to least frequent.

• Sagging hips. The lower back drops, the pelvis tips forward, and the load transfers from the abdominals to the passive structures of the spine. If you feel a plank in your lower back, this is why. Fix it by tucking the pelvis slightly (imagine bringing your ribs and hip bones closer together) and squeezing the glutes.
• Hips too high. This is usually a way of making the exercise easier without noticing. Your shoulders, hips and heels should form a straight line.
• Head dropped or craned up. Look at the floor about 12 inches (30cm) in front of your hands, keeping the neck in line with the spine.
• Holding your breath. If you can’t breathe normally throughout, the position is too hard. Being able to hold a conversation during a plank is a reasonable standard.

A useful self-check is to film yourself from the side for one set. Almost everyone is surprised, and one video corrects more than a month of guessing.

What to skip

Sit-ups and crunches get the movement, the position and the duration wrong. Russian twists load spinal rotation under fatigue and are usually done fast with poor control, when the trunk’s job in running is to resist rotation.

Very long planks don’t add much either. Beyond about a minute you’re mostly training tolerance for discomfort, and the record-holders are not better runners for it. Finally, drop anything that hurts your lower back. Pain there is almost always a sign the exercise has exceeded your control, so regress it.

Fitting it into a running week

Two 15-minute sessions is the whole commitment. Put them after an easy run rather than before, since a fatigued trunk going into a run is precisely the state you’re trying to avoid. At least at first, don’t do core work the day before a hard session.

Give it six to eight weeks before you expect to notice anything; nothing here works in two weeks. If you only have time for one thing, do the side plank and the single-leg glute bridge. They target pelvic control, which carries the best evidence.

For how this fits with overall training load, see building weekly mileage safely.

Why this routine looks the way it does

The claim that core training improves running economy is not consistently supported, so treat confident assertions either way with suspicion. The better justification is pelvic control in single-leg stance, which connects directly to the well-evidenced hip work for runner’s knee. Trunk endurance matters more than trunk strength, because fatigue degrades running mechanics.

So train anti-rotation, anti-extension and anti-lateral-flexion, and skip sit-ups entirely. Two 15-minute sessions a week after easy runs is enough, and expect six to eight weeks before you notice anything.

This article is general information, not medical or coaching advice.

References

1. Hung KC et al. Effects of 8-week core training on core endurance and running economy. PLoS One, 2019. ncbi.nlm.nih.gov
2. Sato K, Mokha M. Does core strength training influence running kinetics, lower-extremity stability, and 5000-m performance in runners? Journal of Strength and Conditioning Research, 2009. pubmed.ncbi.nlm.nih.gov
3. Drum SN, Rappelt L, Donath L. Trunk and upper body fatigue adversely affect running economy: a three-armed randomized controlled crossover pilot trial. Sports, 2019. ncbi.nlm.nih.gov