Strength Training Mistakes That Are Slowing Your Progress

If you’re a runner who secretly feels out of place in the weight room, you’re not alone. 

I’ve seen it countless times – people who can hold a steady pace for kilometres suddenly look unsure the moment a barbell enters the picture. 

Strength training often feels optional, confusing, or even risky if your main identity is “runner.”

But here’s the truth most people discover late: it’s rarely the lack of effort that slows progress.

It’s how you’re training.

Strength work, when done right, doesn’t make you bulky or slow. It makes you faster, more resilient, and far less likely to be injured. 

When done wrong, it becomes wasted time – or worse, the reason you stall completely.

Let’s talk about the most common strength-training mistakes that quietly hold runners back.

1. Skipping Strength Training Altogether

This is the most obvious mistake – and still the most common.

Many runners believe running alone is enough. 

If the mileage goes up, performance should follow, right? Sometimes it does. Until it doesn’t.

Running is repetitive. 

Every step loads the same joints, tendons, and muscles again and again. Strength training is what prepares your body to handle that repetition.

It improves force production, stability, and how efficiently your muscles work with your tendons.

Without it, your body compensates. 

One muscle takes over for another. 

Small imbalances turn into injuries. 

Progress slows, even though effort increases.

Strength training isn’t cross-training. It’s infrastructure.

2. Ignoring Single-Leg Work

This one shows up everywhere in gyms.

Squats. Deadlifts. Leg presses. 

All solid movements – but many runners stop there. 

The problem is simple : running happens one leg at a time.

If you never train single-leg strength, you’re leaving stability and power on the table.

Lunges, step-ups, Bulgarian split squats, single-leg glute bridges – these movements expose weaknesses you can hide in bilateral lifts.

That slight wobble in a single-leg squat? That’s the instability showing up as inefficiency in your stride.

Strong runners aren’t just strong. They’re stable on one leg, over and over again.

3. Lifting Too Light, Forever

There’s a comfort zone many runners never leave: light weights, high reps, minimal rest.

It feels safe. It feels productive. You’re sweating, breathing hard, and sore the next day. 

But the soreness isn’t progressing.

At some point, strength training has to actually build strength. That requires loads. 

Not recklessness – but intention.

Heavy lifting (done with good form) improves force development. 

That’s what helps you push off the ground more efficiently, sprint the last stretch, or climb hills without your form falling apart.

If you’ve been using the same weights for months, your body has already adapted. 

You’re maintaining, not improving.

4. Turning Every Lift Into Cardio

Runners love intensity. So when they lift, they often rush.

Short rest. Circuits. Timers. Minimal recovery.

The problem is that strength training and conditioning are not the same thing. 

When rest disappears, so does force output. You’re training fatigue tolerance, not strength.

In the weight room, slowing down is often the smarter move. Fewer reps. Heavier weight. 

Proper rest between sets. Focused movement.

You already train your aerobic system on the road. 

The gym should train your muscles, not compete with your runs.

5. No Progression, No Direction

Some people lift consistently and still see no change. 

The reason is simple: nothing is progressing.

Same exercises. Same reps. Same weight. Week after week.

Strength training should move somewhere. More control. More load. Better execution. 

If nothing changes, neither will your results.

Progress doesn’t mean jumping weight every session.

It can mean one more rep with perfect form. An extra set. 

A slightly heavier load after weeks of adaptation.

Random workouts lead to random outcomes.

6. Training While Exhausted

There’s a fine line between discipline and self-sabotage.

Lifting immediately after a hard run, while dehydrated and depleted, often means something suffers. Either the strength work becomes sloppy, or recovery gets compromised.

Strength training requires quality effort. 

If you’re constantly dragging yourself through sessions, you’re reinforcing poor patterns instead of building resilience.

Sometimes the smartest move is adjusting the schedule. 

Sometimes it’s taking an extra rest day. 

Progress doesn’t come from doing more – it comes from doing enough, well.

7. Wearing the Wrong Shoes

This seems small, but it matters.

Soft, cushioned running shoes absorb force. That’s great on the road. Not ideal under a barbell.

When you lift, you want stability. You want to feel the ground. 

Excess cushioning reduces force transfer and balance, especially during squats and deadlifts.

You don’t need expensive lifting shoes. Flat, firm soles work. 

Even a basic hard-soled trainer is better than highly cushioned running footwear.

Your feet are your foundation. Treat them like it.

8. Chasing Looks Instead of Function

Social media has blurred the line between training and posing.

Many people train for aesthetics – what looks good in the mirror – rather than what performs well in real movement. 

Endless isolation work. 

Minimal attention to how the body moves as a system.

But the runners who last aren’t the ones with the best lighting. 

They’re the ones whose bodies function well under load, fatigue, and repetition.

Train movement. Train balance. Train strength that carries over to the road. 

The visual changes follow naturally.

Final Thoughts

Strength training isn’t about doing more. It’s about doing it right.

When runners stop treating the weight room as an afterthought—or a punishment—they unlock another level of performance. Fewer injuries. Better efficiency. More confidence in their bodies.

You don’t need to live in the gym. You just need a plan, patience, and the willingness to lift with purpose.

Progress isn’t blocked by effort. It’s blocked by mistakes you don’t realise you’re making.

Fix those, and everything starts moving again.