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Strength Training for Runners: How to Fit It In Without Losing Running Fitness
Most runners know they should be strength training. Few actually do it consistently because it's not clear where it fits, how much is enough, or whether it'll interfere with their running. This post answers all of that. No fluff, just what actually works.
Strength training isn't optional for runners: it's part of the training. But for a long time, runners treated it like something separate, something you did in winter or when you were injured. That's changing, and for good reason.
The question most runners have isn't "should I strength train?" anymore. It's "how do I actually fit it in without feeling like I'm doing too much?" That's what this post is about.
Why strength training makes you a better runner
Running is a single-leg sport. Every stride, you're landing on one leg and absorbing forces equal to two to three times your body weight. If your hips, glutes, and legs can't control that load efficiently, your body compensates and those compensations eventually turn into injuries.
Strength training fixes this by building the muscular capacity to handle running load. It also improves your running economy — the efficiency with which your muscles generate force. Several studies have shown that runners who add consistent strength training improve their running economy by 2–8%, which translates directly into faster times or less effort at the same pace.
In plain terms: stronger muscles mean better joint support, more stable running form, fewer injuries, and more power on climbs and sprints with less effort.
For trail runners specifically, it's even more important. The lateral stability demands of uneven terrain, the quad loading on descents, the hip flexor and calf work on steep climbs. None of that gets trained by running alone.
What exercises actually matter for runners
You don't need to spend hours in the gym or follow a bodybuilder programme. Runners need functional strength movements that translate directly to better running mechanics. That means compound exercises that target the hips, glutes, quads, hamstrings, and core.
These are the exercises I prioritise with my athletes:
Builds leg stability and glute/ hamstring strength.
Strengthens hamstrings and glutes, the primary drivers of running propulsion
Mimics the single-leg push-off in running, trains glutes and quads together
Isolates glute max, the muscle most runners are underusing on every stride
Builds Achilles tendon resilience and calf capacity, both critical for injury prevention
Core stability keeps your pelvis level when you're fatigued late in a run
Hip abductor strength prevents knee drop and IT band issues
One of the most effective hamstring injury prevention exercises in the research
What about the gym?
You don't need one. Most of these exercises can be done at home with a resistance band and a pair of dumbbells. The goal isn't to lift heavy. It's to build the specific strength patterns that running demands. A 25-minute session twice a week is more effective than one long gym session you never quite manage to schedule.
One useful trick: Use supersets: while one muscle group rests, work another. For example, alternate between single-leg squats (legs) and plank holds (core). You'll cut the session time in half without losing any of the benefit.
When to strength train and when not to
This is where most runners get it wrong. They think strength training and hard running are separate things that don't interact. They do.
The general rule: don't do heavy lower-body strength training the day before a key running session. If you have a tempo run or interval session on Friday, doing a heavy leg session on Thursday will lower the quality of that run. Your legs will be pre-fatigued and you won't get the training stimulus you're after.
Instead, place strength sessions on easy run days or on the day after hard runs. This way your key sessions stay high quality and strength work supports rather than competes with your running.
The exception: upper body and core work can happen any day without affecting running performance. If your schedule is tight, those can go on a harder run day without issue.
One more thing: in the first 2–4 weeks of adding strength training, you may feel heavier on your runs. That's normal. Your nervous system & body are adapting. That feeling will pass, and what follows is noticeably better running.
A sample week that works
Here's what a realistic training week looks like for a runner doing 4 running sessions and 2 strength sessions. Adjust based on your own volume.
| Day | Session | Notes |
|---|---|---|
| Monday | Run Easy 45–60 min | Low intensity — conversational pace |
| Tuesday | Strength Full body 30–40 min | Core Foundation I* x Start to Plyometrics: Balance I* |
| Wednesday | Run Tempo or intervals | Key quality session — legs fresh after strength day |
| Thursday | Strength Upper body + core only | Core Foundation II* x Lower Body Foundation I* |
| Friday | Run Medium effort 60 min | Steady state or fartlek |
| Saturday | Run Long run | Easy to moderate pace — build endurance base |
| Sunday | Rest or active recovery | Walk, yoga, foam rolling — let the body adapt |
*Not sure where to start? These workouts are all available inside of the app. You can try it free for 7 days and get access to 100+ strength workouts designed specifically for runners.
This is a template, not a prescription. Your week will look different depending on your goal race, current fitness, and life. The principle that stays constant is: protect your key running sessions by keeping strength away from the day before.
The most common mistakes runners make with strength training
Doing too much too soon
Starting with five strength sessions a week, running six days, and wondering why everything hurts. Start with two strength sessions per week (20-30min), keep them short, and build gradually. Consistency over 12 weeks beats intensity over 3 weeks every time.
Prioritising the wrong muscles
Spending time on bicep curls and chest press when your glutes and single-leg strength are the limiting factor. For runners, the lower body and core are almost always where the investment pays off.
Stopping when training loads go up
Many runners drop strength work as their running volume increases, especially in race build-up phases. This is the opposite of what you should do. Maintaining strength (even at reduced volume, one session a week) during high running load is what protects you from the injury risk that comes with heavy training.
Treating it as optional
Strength training is not a nice-to-have. It's part of your training. Schedule it like a run, not like a gym visit you'll get to eventually.
The short version
- ✓Strength training improves running economy, reduces injury risk, and builds power for hills and sprints
- ✓Focus on compound, functional movements — single-leg squats, deadlifts, step-ups, calf raises, core
- ✓Twice a week, 25–40 minutes is enough, you don't need a gym
- ✓Avoid heavy lower-body strength the day before key running sessions
- ✓Don't drop strength work when running volume increases, but reduce it, (DON'T remove it)
- ✓The first few weeks may feel heavy, but that will be replaced with long-lasting benefits.
Strength training doesn't take time away from running. Done right, it makes every run better: you recover faster, run more efficiently, and stay healthier over longer periods of training. Two sessions a week, consistently, is all it takes to see the difference.
Want a strength programme built specifically for your running?
The Advanced and VIP coaching plans include a 12-week runner-specific strength programme alongside your personalised training plan. Or explore the Run Smarter App for structured workouts you can do at home.
