RPE and RIR explained

Why use effort instead of fixed weights?

A programme that says '5 sets of 5 at 100 kg' assumes you are the same person every week. You are not. A bad night's sleep, a stressful week at work or a hard run the day before can knock your strength noticeably. A programme that says '5 sets of 5 at RPE 7' lets the weight float to match the day.

This is called autoregulation. On good days you lift a bit more, on rough days a bit less, and the training stimulus stays roughly the same. It also stops you grinding out sets you had no business attempting.

It is especially helpful for anyone who does other training. A HYROX athlete lifting the day after a long run will not be as strong as on a rested day, and effort-based targets account for that automatically.

Rating honestly is a skill

People new to lifting reliably underestimate how many reps they have left, often by a wide margin. A beginner who calls a set RPE 9 may have had four or five reps in the tank. That is normal, and it improves quickly with practice.

The simplest way to calibrate is to occasionally take a set to genuine failure on a safe exercise, such as a leg press, machine row or dumbbell curl, and compare the result with your guess. Do not practise this on heavy barbell squats or bench press without a spotter and safety bars.

Bar speed is a helpful clue. When a rep slows noticeably, you are usually within two or three reps of failure. When a rep grinds for a second or two, you are usually one away, or at the limit.

How to use RPE in a programme

Heavy main lifts usually sit at RPE 7 to 8, which keeps technique clean. Accessories and machine work can be pushed to RPE 9, or occasionally 10, because failing a cable fly carries very little risk. A simple way to use it in each session:

1. Warm up to a weight you think is roughly right for the target.
2. Do your first working set and rate it honestly.
3. If it was well under target, add weight. If it was over, take some off.
4. Use that weight for the remaining sets, adjusting only if something feels clearly off.

Across a block, you can nudge the target up week by week, for example from RPE 7 in week one to RPE 8.5 in week four, before a lighter week. That is a straightforward way to build progressive overload into a plan without rigid percentages.

A worked example

Say your plan for the week is 3 sets of 6 on the bench press at RPE 8. Last week you used 60 kg. You warm up and do your first working set at 62.5 kg. The sixth rep slows, but you are confident you had two more in you, so that set was RPE 8, right on target.

On Thursday you slept badly and the same 62.5 kg feels like RPE 9 on the first set. Instead of forcing it, you drop to 60 kg for the remaining sets. The following week you feel great and 65 kg lands at RPE 8. Over a month the weight still climbs, but it climbs on the days your body is ready.

That flexibility is the whole point. Rigid percentage programmes can work well, but they quietly assume ideal sleep and recovery. Most people with jobs, families and commutes do not live that life.

Different lifts, different targets

Not every exercise should be pushed equally close to failure. Technical barbell lifts such as squats, deadlifts and cleans tend to break down in form before the muscles truly give out, so RPE 7 to 8 keeps them safe. Stable, simple exercises such as leg presses, machine rows, cable work and curls can be taken closer to the limit.

Bodyweight exercises work well with RIR too. If you can do 12 pull-ups on a fresh day, sets of 8 or 9 leave two or three in reserve and let you do more total quality reps across a session than one all-out set followed by several ugly ones.

Where RPE falls short, and what it reveals over time

Very high rep sets are hard to rate because breathlessness and muscle burn cloud the picture. Complete beginners also get less out of it at first, since their estimates are rough and simple progression works well regardless. For them, a clear weight and rep target is usually better for the first few months.

RPE is also not an excuse to back off every time training gets uncomfortable. Good lifting is hard work. The aim is to match effort to the plan, not to avoid effort.

Over longer periods, though, the numbers become very revealing. If the same weight keeps feeling harder week after week, that is useful information. It can mean you need more sleep, more food or a planned deload week. Noticing that trend is a structured way of listening to your body rather than guessing.

Calibration happens faster with someone watching your reps. The 7-day free trial at Lycan Strength includes a complimentary fitness assessment, which is a sensible place to find your starting weights.