Most runners know they should be doing some strength work.
Very few are doing it, and of the ones who are, a good proportion are doing something that will not make much difference. Usually some bodyweight exercises, a resistance band, and a core routine learned from a video several years ago.
So here is a straightforward account of what strength training for runners is for, what it should actually involve, and how to fit it around training you are already doing.
Why it matters
Running is a repetitive single leg impact activity. Every step asks one leg to absorb your body weight at speed and then propel you forward.
Over a long run that is thousands of repetitions, and your ability to handle them without breaking down depends on how much capacity you have relative to the demand.
Strength work raises the capacity. It is that simple.
Running itself does not do this. Running builds a very specific kind of endurance and it does not build strength, because the loads involved are too low and too repetitive to drive that adaptation. A runner who only runs is slowly getting better at running and no better at tolerating the forces involved.
There are performance reasons too. Stronger legs produce more force per step, which generally translates into better running economy, meaning you use less energy at a given pace. But injury resilience is the main argument for most people.
Where runners usually go wrong
Three common mistakes.
Training too light. Sets of twenty with bands or light weights feel like effort and do not provide enough stimulus to build meaningful strength. Strength work should be genuinely hard by the last couple of repetitions.
Never progressing. The same routine, with the same weight, for the same number of reps, for a year. That maintains whatever you have. It does not build anything.
Doing core work instead of strength work. Planks and abdominal exercises have their place and they are not a substitute for loading your legs.
A fourth, less common but worth mentioning: doing so much that it interferes with running. The point is to support the running, not to compete with it.
What to actually do
Two sessions a week is enough for most runners. Three if you are not in a heavy training block and you enjoy it.
Twenty to forty minutes is plenty. This does not need to be a long gym session.
The core of it is a small number of movements, loaded progressively.
A squat pattern. Back squat, goblet squat, split squat or leg press, depending on what you have access to and what suits you.
A hinge pattern. Deadlift, Romanian deadlift, or hip thrust. This covers the back of the body, which runners frequently neglect and which matters a great deal for the hamstrings and glutes.
Single leg work. Split squats, step ups, single leg deadlifts. Running happens on one leg at a time, so training on one leg at a time is specific and it exposes side to side differences you would otherwise miss.
Calf work. This deserves its own mention because the calf complex takes enormous load in running and is heavily involved in the most common running injuries. Heel raises with a straight knee and with a bent knee, since they load different parts, and progressed to meaningful weight rather than sets of thirty bodyweight raises.
Some upper body and trunk work. Rows, presses, carries. Carries in particular are useful and underrated.
That is the whole thing. Six or seven movements, two sessions a week.
How heavy
Heavier than most runners think.
A reasonable guide is a weight you could lift somewhere between six and twelve times before your form starts to go. If you could comfortably do twenty, it is too light.
You do not need to train to failure, and you do not need to be chasing maximal lifts. You do need the last couple of repetitions in a set to feel genuinely difficult.
And you need to add weight over time. When a given weight stops feeling hard at the top of your rep range, that is the signal to increase it.
Write it down. Without a record you will not notice that you have been lifting the same weight since February.
Fitting it around running
The usual question is whether strength work will leave you too sore to run.
Some soreness in the first few weeks is normal and it settles as your body adapts. It is not a reason to stop.
A few practical points.
Keep hard running days and hard strength days separate where you can, or put them on the same day so that your easy days are genuinely easy. What works less well is alternating hard efforts every single day with no recovery.
Avoid heavy leg work the day before a key session or a race.
If you have to choose on a given week, protect the running. Strength is the support act.
And start with one session a week if two feels unmanageable. One consistently is considerably better than two for a fortnight and then nothing.
What about plyometrics and speed work
Jumping and hopping work has a role, particularly for tendon health and for developing the elastic qualities running depends on.
It is worth building up to rather than starting with, especially if you are coming back from an injury or you have not done any loading work before.
Start with basic strength for a few weeks, then introduce low level hopping and skipping, and progress gradually from there.
And it should be done fresh, early in a session, rather than at the end when you are tired.
If you are coming back from an injury
Strength work is frequently the thing that was missing in the first place.
Two things to be aware of.
Side to side comparison matters enormously. If one leg is meaningfully weaker than the other, that gap is almost certainly relevant and it tends to persist long after the pain has gone.
And the strength you need is specific to what failed. A runner with a history of Achilles trouble needs calf capacity in particular. A runner with a history of kneecap pain needs quadriceps and hip work. A general program is a good start and a targeted one is better.
What it will not do
Being honest about the limits.
It will not compensate for a training error. Doing squats twice a week does not make it safe to double your mileage in a fortnight.
It will not fix a current injury on its own, though it is usually part of the solution.
And it will not transform your times. The gains in economy are real and modest, and the main return is on consistency, which is where the actual performance improvement comes from.
A runner who trains consistently for three years because they stayed healthy will beat the version of themselves who ran faster for four months and then spent two months injured.
When to get assessed first
Worth having a look before you start if you have a current injury or pain that limits you, a previous injury that never fully resolved, a noticeable difference between sides, or if you are unsure about technique on loaded movements.
And speak with your physician before starting a resistance program if you have cardiovascular risk factors or other health conditions.
Build the capacity, keep the consistency
The most common thing we see is a runner who is doing everything right with their running and nothing at all with their strength, and who cannot work out why the same injury keeps finding them every year.
Running Injury Expert Rehab offers a free discovery visit at no cost and no obligation. You will get an assessment of your strength with side to side comparison, an honest read on where your gaps are, and a program that fits into two short sessions a week around the running you already do.