5 Reps or 15 Reps? Which Is Better for Getting Stronger?

What’s better for building strength and lean muscle in your 40s and beyond?

Sets of 15 with lighter weights or sets of 5 with heavier weights?

It’s a question we often get, and we used to wonder about it too.

The problem is, it’s the wrong question.

Your Muscles Are Dumb

See, muscles are dumb.

They get stronger from the tension created when you lift weights, not because you did 5 reps instead of 15.

This is why you can get stronger using bands, machines, dumbbells, or even soup cans if you’re just starting.

They all create mechanical tension on your muscles.

But even though muscles are dumb, they’re kinda smart too.

They only get bigger and stronger if they have to. They’re lazy like that.

Not enough mechanical tension = sad progress.

The right amount of mechanical tension = “Wow, you’re strong, and you look great.”

So, a better question than “Should I do 5 or 15 reps?” is:

How do I create enough mechanical tension to get stronger and build lean muscle?

I’m so glad you asked.

The Answer: Train at the Right Intensity

Intensity, or your effort level, is the missing piece that, when combined with progressive overload, can take your strength and body composition to new heights.

Here’s the simplest way I can explain intensity in your workouts.

Imagine you’re doing a set of dumbbell curls with 15-lb dumbbells.

At 10 reps in, the weights are still moving, but you’re about to call it quits.

I walk up to you and say:

“For every rep you do fewer than 20, you have to pay me $20.”

With those stakes, you push through and finish all 20 reps, even though the last few were really hard.

That’s intensity. That’s effort.

If you stop your set of curls at 10 reps when you could have done 20, you’re leaving a ton of progress on the table.

Those last few reps that were tough created a high level of mechanical tension, which is a big part of the stimulus responsible for the progress you want to make.

When you compound that level of effort workout after workout, you’ve got something special.

Does That Mean You Should Train to Failure?

No.

I’m not saying you should always train to failure, and I’m not saying every exercise has the same “rules” for how hard you should push.

What I am saying is, if you’ve been doing the same routine with the same weights for weeks or months, we should talk. 😁

The goal isn’t to make every workout brutally hard.

The goal is to give your muscles a reason to adapt, then gradually increase the demands you place on them over time.

That’s where intensity and progressive overload come together.

Want to Learn More?

Blakley and I talked more about intensity and progressive overload in our seminar on Strength Training at the Airstream Rally.

You can watch the full seminar here:

Watch the Strength Training Seminar

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