How Heavy Should I Lift? Understanding RPE for Strength

If you're wondering how heavy you should lift, the short answer is this: you should use a weight that is challenging enough to stimulate progress but not so heavy that your technique breaks down. For most people, that means finishing a set with a few good repetitions still left in reserve.

At PhysEd, we use RPE (Rate of Perceived Exertion) to help members choose the right weight for each workout. Rather than guessing or chasing arbitrary numbers, RPE helps you train hard enough to improve while still recovering well enough to come back and train again tomorrow.

What Is RPE?

RPE stands for Rate of Perceived Exertion. It's a simple scale from 1–10 that measures how difficult a set feels.

In strength training, RPE helps determine not just how much weight is on the bar, but how hard you're actually working.

An RPE 10 means you've reached your limit and couldn't complete another repetition.

An RPE 9 means you probably had one more rep available.

An RPE 8 means you likely had two reps left in reserve.

This concept is often referred to as Reps in Reserve (RIR).

For most strength and conditioning training, we spend a lot of time working around RPE 7–8.

Why Shouldn't I Lift As Heavy As Possible?

Many people assume that getting stronger means lifting maximal weights all the time.

It doesn't.

Strength gains happen when you expose your body to a challenging training stimulus and then allow it to recover. Constantly training to failure often creates more fatigue than necessary and can actually make it harder to recover between sessions.

Research consistently shows that training close to failure can produce similar improvements in strength and muscle growth as training to failure, while allowing better recovery and more consistent progress.

You don't need to destroy yourself to improve.

You need to challenge yourself consistently.

How Heavy Should I Lift for Strength?

If your goal is strength, a good rule of thumb is to choose a weight that allows you to complete the prescribed repetitions while finishing with 1–3 reps left in reserve.

For example:

Workout: 5 reps at RPE 8

You should select a weight that feels difficult but still leaves roughly two good reps available.

If you could have done five more reps, the weight was probably too light.

If you barely survived the fifth rep and your technique fell apart, it was probably too heavy.

The goal is finding the sweet spot between too easy and too hard.

Does the Weight Change From Day to Day?

Absolutely.

One of the biggest advantages of RPE-based training is that it accounts for real life.

Sleep, work stress, nutrition, travel, illness, and recovery all affect performance.

A weight that feels like an RPE 8 on Monday might feel like an RPE 10 on Thursday if you've had a rough week.

Rather than forcing yourself to hit a predetermined number, RPE allows you to adjust while still achieving the intended training effect.

This is one of the reasons we use RPE throughout our strength and conditioning classes at PhysEd.

How Do Beginners Know If They're Using the Right Weight?

This is where coaching becomes valuable.

One thing I've noticed after coaching hundreds of people is that beginners almost always make the same mistake: they either lift far too light because they're afraid of failure, or they lift too heavy because they think every workout should feel maximal.

Both approaches slow progress.

The skill of accurately judging effort develops over time. After a few weeks of consistent training, most people become much better at estimating how many repetitions they have left and selecting appropriate loads.

That's one reason why small-group coaching can accelerate progress. You learn not only what to do, but how hard to do it.

What If My Goal Is General Fitness?

For general fitness, health, and longevity, there is no need to constantly chase maximum weights.

Instead, focus on:

• Good technique

• Consistent training

• Progressive overload

• Appropriate effort

• Long-term sustainability

At PhysEd, our goal isn't simply to help you lift heavier weights.

It's to help you become a stronger, more capable human being who can move well for years to come.

Often that means lifting heavy enough to create adaptation while leaving enough energy to come back and train again tomorrow.

So, How Heavy Should You Lift?

You should lift a weight that matches the goal of the workout.

Most of the time, that means choosing a load that feels challenging while still leaving 1–3 repetitions in reserve.

That's heavy enough to drive progress, light enough to recover from, and sustainable enough to keep you training consistently over the long term.

If you're unsure where that balance lies, that's exactly what a coach is there to help you discover.

If you're new to strength training, check out our Classes page to learn how we coach beginners and experienced athletes alike.

Ready to Learn How Heavy You Should Lift?

The best way to learn is through experience.

Book a free intro class at PhysEd and we'll show you how to choose appropriate weights, understand RPE, and train with confidence—whether you're completely new to strength training or looking to take your performance to the next level.

Frequently Asked Questions

Should beginners train to failure?

Generally, no. Most beginners benefit from stopping 1–3 reps before failure while they develop technique and confidence.

What is a good RPE for strength training?

Most strength work is performed between RPE 7 and RPE 9, depending on the goal of the session.

Is RPE better than percentage-based training?

Neither is inherently better, in fact we use both. Percentage-based training works well when performance is predictable. RPE works well because it adapts to daily fluctuations in readiness and recovery.

How do I know if a weight is too heavy?

If your technique breaks down significantly or you cannot complete the prescribed repetitions, the weight is likely too heavy for the intended training effect.

Can I build muscle without training to failure?

Yes. Research shows that training close to failure often produces similar muscle growth while creating less fatigue.