RPE Scale: How to Judge Effort When You Are Tired
Some days you walk into a workout feeling strong. Other days you have had four hours of broken sleep, a toddler meltdown at breakfast and a stressful call before lunch, and the same kettlebell feels twice as heavy. A fixed plan that says “use 12 kg for 10 reps” does not care how your day went. The RPE scale does. It is a simple way to judge your effort from how hard a set feels, so you can train well on good days and still train safely on rubbish ones.
What is the RPE scale?
RPE stands for “rate of perceived exertion”. It is a score you give yourself for how hard something felt. There are a few versions, but the one I use with parents is a simple 1 to 10 scale:
| RPE | How it feels | Talk test |
|---|---|---|
| 1 to 2 | Very easy. Resting, gentle stroll. | Could sing |
| 3 to 4 | Easy. Brisk walk, warm-up. | Chatting easily |
| 5 to 6 | Moderate. Working, but comfortable. | Can talk, not sing |
| 7 to 8 | Hard. Focused effort. | Short sentences only |
| 9 | Very hard. Nearly done. | A word or two |
| 10 | Maximum. Nothing left. | Cannot talk |
The talk test lines up nicely with the NHS description of activity in its physical activity guidelines for adults: moderate activity means you can still talk but not sing, and vigorous activity means you cannot say more than a few words without pausing for breath.
RPE for lifting: “reps in reserve”
For strength exercises, it is easier to think in terms of how many more good reps you could have done. This is called reps in reserve, or RIR.
- RPE 10 = 0 reps left. You could not do another rep.
- RPE 9 = 1 rep left.
- RPE 8 = 2 reps left.
- RPE 7 = 3 reps left.
- RPE 6 or lower = 4 or more left. Technique and warm-up territory.
Most of my beginner clients do their main sets at RPE 7 to 8: hard enough to make progress, with enough left in the tank to keep good form. You rarely need RPE 10, and I would avoid it on bigger lifts like squats and deadlifts.
How to use the RPE scale when you are tired or stressed
This is where RPE really helps busy parents. Instead of forcing a fixed weight, you aim for a target effort and let the weight move.
Step 1: Set the target, not the weight
Your plan says: goblet squat, 3 sets of 10 at RPE 7 to 8. On a good day that might be 12 kg. On a bad night’s sleep it might be 10 kg. Both sessions do their job.
Step 2: Use your first set as a check-in
Do your first working set and rate it honestly. If it felt like RPE 9 with the usual weight, drop down. If it felt like RPE 6, go up a little.
Step 3: Adjust the session, not just the weight
On really rough days, cap everything at RPE 6 to 7 and do one set fewer. You still move, you still keep the habit, and you will probably feel better afterwards. The NHS has useful self-help tips to fight fatigue, and gentle exercise is one of them.
Step 4: Write it down
Note the weight, reps and RPE. Over a few weeks, you will see the same weight drop from RPE 8 to RPE 6. That is your proof you are getting stronger, and your cue to apply progressive overload.
A sample week using RPE
- Session 1 (strength): goblet squats, rows, RDLs, push-ups. 3 sets of 8 to 10 each at RPE 7 to 8.
- Session 2 (conditioning): 20-minute circuit. Work intervals at RPE 7 to 8, rest until you are back to RPE 3 to 4.
- Daily walks: RPE 4 to 5. School run, a loop of the park, walking to the shops.
If you like interval training, my guide to HIIT for beginners shows how to use effort levels for work and rest periods.
Common RPE mistakes
- Being a hero. Calling a grinding, ugly set a 7. Be honest. If your form changed, it was at least a 9.
- Being too cautious. Beginners often stop at RPE 5 because hard feels unfamiliar. A few hard sets are where progress comes from.
- Rating the whole session, not the set. Score each working set.
- Ignoring warning signs. Pain, dizziness, chest discomfort or unusual breathlessness are not “high RPE”. Stop and seek medical advice. If you have a heart condition, high blood pressure or another health condition, check with your GP about what intensity is right for you.
Why I use RPE in my classes
In a group of up to 10 people, everyone arrives with a different day behind them. RPE lets each person work at the right level without me needing a different plan for everyone. I will often call out “this round, RPE 7” and you pick the band, kettlebell or variation that gets you there. The SYP Recharge energy and focus class is built around this: it is designed to leave you with more energy than you came in with, not flatten you.
FAQs
What RPE should a beginner train at?
Mostly RPE 6 to 8. Start nearer 6 while you learn the moves, then work up to 7 to 8 for your main sets once your technique is consistent.
Is RPE accurate?
It is subjective, so it takes a few weeks to calibrate. Once you have practised, it is a reliable way to manage effort, especially when tiredness and stress change day to day.
What is the difference between RPE and heart rate?
Heart rate is measured by a device. RPE is how hard it feels to you. Both are useful, but RPE needs no watch and accounts for things like poor sleep and stress.
Should every set be at RPE 10?
No. Going to complete failure often increases fatigue and the risk of poor form. Leaving 1 to 3 reps in the tank works well for most people.
Book your first class
Come and learn what RPE 7 really feels like. SYP Bootcamp runs 45-minute small-group classes in a weatherproof church hall in Archway N19, max 10 people, £15 a class, with an easier and harder option for every exercise. Book your £15 class here or call or WhatsApp me on 07301 512215. If you would rather train with your partner or a friend and share the cost, take a look at my partner personal training in Archway.
About the author
Artem Olekhnovych is a personal trainer in Archway and the founder of SYP Fitness and SYP Bootcamp. He has coached clients in Archway, Highgate and across North London for over 10 years, and runs small-group bootcamp classes for busy mums and dads. Read reviews from his 1-1 clients.
