Should You Program With RPE or Percentages?

Use percentages of 1RM to plan the block and RPE to read the day. A percentage sets the load from a tested max, so it works best when that max is recent and the lifter's technique is stable. RPE sets the load from how hard today's set feels, so it works best for lifters who can rate effort honestly and whose days vary. Lifters who cannot rate effort yet should start with percentages. Most lifters past their first year or two do well with both: a top set by RPE and back-off sets as a percentage of that top set.

The six-question quiz at the top of this page gives you a starting point for yourself or for an athlete you coach. The rest of this article explains each result.

What is the difference between % of 1RM and RPE?

Both answer the same question: how heavy should this set be? They get the answer from different places.

A percentage of 1RM takes the load from a number you already have. If the lifter's back squat max is 180 kg, 80% is 144 kg, whatever kind of day it is. The bar weight is fixed before the session starts, which makes it objective.

RPE (rating of perceived exertion) takes the load from the lifter's own rating of the set. On the strength-training version of the scale, RPE 10 means no reps left, RPE 9 means one rep left and RPE 8 means two. "3 reps at RPE 8" means the lifter picks a weight they could have lifted five times. The load moves with the day, and it depends on how well the lifter judges their own effort, which makes it subjective.

When do percentages work best?

Percentages work when you can trust the max. That means it was tested or hit in the last few weeks, the lifter's technique has not changed much since, and their weeks look roughly alike. Then the numbers on paper match what the bar feels like, and you can plan a whole block in advance: how heavy each week gets, when the heavy singles land and when the lifter backs off.

They are also the better choice for newer lifters. Someone in their first year usually cannot tell a set with two reps left from a set with four, so asking them to choose their own load hands the decision to a guess. A percentage takes that decision away. For a true beginner even a tested max is optional. An estimated max from a recent hard set of three to five reps is enough to start, or you can skip percentages and add a little weight each week until progress slows.

Percentages go wrong when the max is out of date. Strength moves, injuries happen, and a max from six months ago can be far from today's. A percentage of the wrong number gives the wrong load every session.

When does RPE work best?

RPE works best when the lifter's readiness changes a lot from one session to the next. Bad sleep, a long shift, travel or a hard sport practice the day before all change what a lifter can do. A fixed 85% can be easy on Monday and a grind on Thursday. RPE lets the load follow the lifter instead of the plan.

It also helps when you have no reliable max: after a layoff, for a lift that is rarely tested such as a pause squat, or for accessory work where a 1RM test makes no sense. And every rated set doubles as a test. A top set with an RPE gives an estimated max from an RPE chart, so you can watch the trend week to week without a max-out day.

The weak point is the rating itself. RPE only works if the lifter's "two reps left" really means two reps left.

Can beginners use RPE?

They can learn it, but most should not have their loads set by it yet. Rating effort is a skill. In the 2016 study that introduced the reps-in-reserve RPE scale, experienced squatters rated a true max closer to a 10 than novices did, which suggests the skill grows with training.

Teaching it costs nothing. Keep the beginner on percentages, and after the last set of each exercise ask how many more reps they could have done. Write it down. When their guesses regularly land within one rep, they are ready for an RPE top set.

Does RPE or percentage training build more strength?

The studies that compare the two find that both work, with a small edge for loads set by effort in trained lifters.

• Helms and colleagues (2018) put 21 resistance-trained men on an 8-week squat and bench program, three sessions a week, with sets and reps matched. One group used percentages of 1RM, the other chose loads by RPE. Both groups got stronger. The difference between them was not statistically significant, though the RPE group had a small advantage in most participants.
• Graham and Cleather ran a 12-week squat program with 31 trained men, twice a week. One group lifted a fixed percentage of their pre-test max, the other set loads by reps in reserve. The reps-in-reserve group gained more strength.

Both studies used trained lifters, so they say little about beginners. The practical reading is that the method matters less than whether the load on the bar fits the lifter on the day. RPE helps with that when the lifter can rate effort. Percentages help when they cannot.

How do you combine RPE and percentages?

The most common setup uses RPE for one top set and percentages for the rest.

1. Work up to a top single at RPE 8, two reps left.
2. Take 90% of that single for the back-off sets, for example 3 x 3.

If the single is 150 kg, the back-off sets are 3 x 3 at 135 kg. On the RTS RPE chart a single at RPE 8 is about 92% of 1RM, so 150 kg puts today's estimated max at about 163 kg, and 135 kg is about 83% of it: roughly RPE 7 for a triple. The back-offs carry the volume with reps to spare, and the whole session adjusts to the lifter's day through one rated set.

The block itself can still be planned in percentages. You might write week 1 at 75 to 80%, build to 85% by week 3 and make week 4 lighter, then use the RPE top set to fine-tune each session inside that plan.

What if the percentages keep feeling too heavy?

Then the max is probably out of date. Say a lifter's back squat max on paper is 180 kg, and 80% for 3 (144 kg) keeps coming in at RPE 8. On the RTS chart a triple at RPE 8 is about 86% of 1RM, which puts their real max nearer 167 kg, more than 10 kg below the number you are programming from.

There are two fixes. Retest the max, or estimate a new one from the rated set and recalculate the block. Or switch that lift to RPE for the rest of the block and go back to percentages once a new max is in. Either way, stop loading from a number the lifter cannot hit.

The short version

Use % to plan the block. Use RPE to read the day.

• Newer lifters, or anyone who cannot rate a set yet: percentages, and start logging reps left.
• Experienced lifters with steady weeks and a recent max: percentages hold up, with an RPE top set as a check.
• Experienced lifters whose days vary or whose max is old: lead with RPE and keep percentages for the plan.

Frequently asked questions

Is RPE the same as RIR? Close. RIR is reps in reserve, the number of reps left in the tank. The strength-training RPE scale is built on it: RPE 8 is 2 RIR, RPE 9 is 1 RIR and RPE 10 is 0.

How often should you retest a max when you program in percentages? Often enough that the percentages still feel the way they should. For most lifters that means once per block, with a heavy single or a rep test at the end of it.

Can you use RPE for the Olympic lifts? Yes, but it is harder. A snatch or a clean and jerk usually misses on technique before the lifter runs out of strength, so "two reps left" is harder to judge than on a squat. Percentages are often the simpler choice for the competition lifts, with RPE for squats, pulls and accessories.

Do you need to test a 1RM to use percentages? No. An estimated max from a recent hard set of three to five reps is enough to start, and the 1RM percentage chart turns it into loads.

Programming percentages in Strength Academy

In Strength Academy you write the percentage once, for example "back squat 5 x 3 @ 80%", and each athlete sees the kilos from their own max. If an athlete has no max for that lift yet, the app asks them for one instead of guessing a load. You can start a free trial and program your next block in percentages.

Sources

• Helms ER, et al. RPE vs. percentage 1RM loading in periodized programs matched for sets and repetitions. Frontiers in Physiology, 2018.
• Graham T, Cleather DJ. Autoregulation by "repetitions in reserve" leads to greater improvements in strength over a 12-week training program than fixed loading. Journal of Strength and Conditioning Research, published online 2019.
• Zourdos MC, et al. Novel resistance training-specific rating of perceived exertion scale measuring repetitions in reserve. Journal of Strength and Conditioning Research, 2016.
• RPE to % of 1RM values: the Reactive Training Systems (RTS) chart, as printed on our RPE chart page.