Blog 1 | Coach Kirsten

If you've ever Googled "should runners lift weights," you've probably gotten a dozen conflicting answers. Some coaches say lift heavy. Others say stick to bodyweight. Most running plans don't mention strength training at all.

Here's the truth: strength training is one of the highest-return investments a runner can make but only when it's done in a way that supports your running, not competes with it.

Why Most Runners Skip Strength Training (And Why That's a Mistake)

The most common reasons runners avoid the weight room are time, confusion about what to do, and fear of getting bulky or sore before a big run. All of these are understandable and all of them are fixable.

What's less fixable is what happens when you don't strength train:

Muscle imbalances develop over time, leading to the overuse injuries that sideline most recreational runners: IT band issues, shin splints, stress fractures, knee pain
Running economy suffers, meaning you burn more energy to cover the same distance
Body composition stalls, because running alone is rarely enough stimulus to change muscle mass

The runners who stay healthy and keep improving year over year almost always have some form of strength work in their routine. It's not a coincidence.

The Biggest Mistake Runners Make in the Gym

Walking into the gym and doing whatever feels familiar usually lots of cardio machines, light weights for high reps, and maybe some crunches is the most common mistake runners make with strength training.

This kind of training doesn't give your body a new enough stimulus to adapt. If you're already running 3–4 days a week, more endurance-style work in the gym just adds fatigue without adding strength.

What actually works is the opposite: heavier loads, lower reps, and movements that target the specific muscles runners rely on most.

What Strength Training for Runners Should Actually Look Like

You don't need to become a powerlifter. But you do need to challenge your muscles in ways that running doesn't.

Focus on these movement patterns:

Single-leg work: Running is entirely single-leg. Exercises like Bulgarian split squats, single-leg deadlifts, and step-ups build the stability and strength your hips and glutes need to absorb impact mile after mile.

Hip and glute strength: Weak glutes are at the root of most common running injuries. Hip thrusts, glute bridges, and lateral band work directly address this and pay dividends quickly.

Posterior chain: Deadlifts and Romanian deadlifts strengthen the hamstrings, glutes, and lower back — the entire backside of your body that drives you forward when you run.

Calf and ankle strength: Calf raises, both straight-leg and bent-knee, build the lower leg resilience that helps prevent Achilles issues and stress fractures.

Core, but not the way you think: Planks and dead bugs matter more than crunches. A runner's core job is to resist rotation and stay stable while your legs move, not to flex repeatedly.

How Often Should Runners Lift?

For most women running 3–4 days a week, two strength sessions per week is the sweet spot. More than that and recovery becomes an issue. Less than that and you won't see meaningful adaptation.

The key is timing. Schedule your strength sessions on the same day as a hard run or an easy run, never the day before your long run or a key quality session. You want your best days to stay your best days.

A sample week might look like:

Monday: Easy run + strength
Tuesday: Rest
Wednesday: Quality run (tempo or intervals)
Thursday: Easy run + strength
Friday: Rest
Saturday: Long run
Sunday: Rest or very easy walk

Will Strength Training Make You Slower or Bulkier?

This is the fear that holds most female runners back, and it's worth addressing directly.

Getting significantly bigger from strength training requires a large calorie surplus, very high training volume, and honestly a lot of effort over a long period of time. Two sessions a week of functional strength work will not make you bulky, it will make you more defined, more resilient, and more efficient.

As for getting slower: in the short term, you might feel some fatigue as your body adapts. Within 4–6 weeks, most runners notice they feel stronger on their runs, recover faster, and handle their mileage with less effort.

How to Know If Your Strength Training Is Actually Working for Your Running

Signs your strength program is well-designed for running:

Your easy runs start feeling genuinely easy
You recover faster between hard efforts
Nagging aches and pains decrease or disappear
Your form holds up better in the later miles of long runs
You feel more powerful on hills

If none of that is happening after 6–8 weeks, the program probably isn't designed with running in mind, it's just generic gym work.

The Bottom Line

Strength training doesn't have to be complicated, time-consuming, or at odds with your running. Two focused sessions per week, built around the right movements and timed properly in your schedule, can be the difference between a runner who keeps getting hurt and one who keeps getting better.

If you want a strength plan that's designed specifically around your running schedule and goals, that's exactly what the strength add-on is built for.