At F45 Training, we want all our workouts to challenge you at the right level – yours.
But how do you know when to push harder – or when easing back could improve your form, pacing, and performance?
Rate of perceived exertion (RPE) helps you answer that question by measuring how difficult exercise feels based on your breathing, muscular fatigue, and remaining energy. Alongside metrics such as weight, speed, and heart rate, RPE can also give you a clearer picture of your effort – in real time.
Read on to learn how the RPE scale works, how to use it across cardio, resistance, and hybrid workouts, and how our new Challenge tracks apply RPE targets to help you train toward your goals.
What is RPE? RPE meaning explained
RPE refers to rate of perceived exertion. It’s a subjective measure of how your body feels during a workout. Measuring your RPE means tuning into signals like your:
- Breathing rate
- Heart rate sensations
- Muscular fatigue
- Sweating
As athlete and F45 trainer Jordi Duff explains: “At F45, we use RPE to help members tap into how their body is feeling that day. Sleep, stress, nutrition, how recovered you are from your last workout – all these variables can change how a workout feels, even if you did the exact same session last week. That’s why with our Challenge tracks, we set a target RPE for each session, so you always know how hard to push yourself.”
Want to know more about our Challenge tracks – and which one’s right for your goals? Find your local F45 studio to explore the programs on offer and join one starting near you.
What is the Borg Rate of Perceived Exertion Scale?
The original RPE scale was developed in the 1960s by Swedish psychologist Gunnar Borg, as a low-cost way to gauge workout intensity when heart rate monitors weren’t accessible.
Borg’s scale ran from six to 20, designed so the numbers roughly tracked heart rate when multiplied by 10. An RPE of 12, for example, would roughly correspond to 120 bpm. It was only ever an approximation, but it gave trainers a simple shortcut in an era without Reebok Smart Rings or LionHeart – F45’s own heart rate monitor.
These days, most modern training uses a simplified 1-to-10 style RPE scale instead. It keeps the core idea of Borg’s rate of perceived exertion but uses it in a more recognizable and easier-to-follow rating system.
How does the RPE scale work?
A simple way to look at the RPE scale is the lower the number, the more you’ve got left in the tank; the higher the number, the closer you are to tapping out. For example:
- RPE 1 to 2: Very light effort. Comfortable movement with little noticeable exertion.
- RPE 3 to 4: Light effort. Breathing increases slightly but conversation remains easy.
- RPE 5 to 6: Moderate effort. You’re working, but the intensity remains controlled and sustainable.
- RPE 7: Challenging effort. Breathing is noticeably harder, full sentences are out, and maintaining the same intensity requires concentration.
- RPE 8: Hard effort. You’re working close to your current limit but still have some remaining capacity.
- RPE 9: Very hard or near-maximal effort. You could sustain the effort only briefly.
- RPE 10: Maximal effort. You couldn’t reasonably increase the intensity or continue at the same level for much longer.
Why use RPE during your workouts? 4 RPE benefits
Using the RPE scale during your workouts is one of the most intuitive ways to train, because it teaches you to tune into what your body is telling you, rather than chasing a fixed number on a screen. Read on to learn how it can improve the performance of your F45 workouts.
1. Adjust your workout to how you feel that day
Some days you walk in and everything clicks. Other days, not so much – and that’s normal. A weight that usually feels like RPE 7 might suddenly feel like a 9 after a bad night’s sleep, lingering DOMS (delayed-onset muscle soreness) from your last session, or something you just can’t quite put your finger on.
Your RPE helps you check in with how you’re moving that day, so our trainers can help you adjust before fatigue turns into bad form, and bad form turns into injury.
2. Know when you’re ready to push harder
The flip side is just as useful. If a move that’s supposed to feel tough keeps feeling suspiciously easy, that’s your body waving a green flag. In this case, it’s time to dial something up – whether that’s your pace in a cardio session or your weight in a resistance workout. This gradual increase is what’s known as progressive overload – and your perceived rate of exertion is what tells you when you’re ready for it.
3. Pace your effort across a workout
You know the story of the tortoise and the hare – slow and steady wins the race. We’re not asking you to move slowly, but the lesson still holds that consistent, controlled effort beats a fast start you can’t sustain.
It’s exactly why we train our members who prep for HYROX to use RPE strategically – holding a controlled RPE effort of 6 to 8 for almost the entire race and saving anything close to a 9 or 10 for the final push to the finish line.
4. Train towards different goals
Here’s the thing – there’s no single “correct” RPE. What you’re chasing depends on what you’re training for. Someone building muscle endurance, for example, might work at a different RPE than someone chasing speed and agility, even in the exact same class.
How F45 Challenge tracks use RPE to personalize your training
The F45 Challenge is a guided 45-day program built around your individual goals. You choose from Power, Lean, or Athlete, but train together with everyone else in the same F45 classes – what changes is the coaching, nutrition guidance, and progress tracking built around what you’re working toward.
RPE is one of the tools our coaches use to tailor that experience for you, guiding how the same workout should feel depending on which track you’re on. Below, we break down each program and how perceived rate of exertion shapes the way you train within it.
Power: use RPE to build strength
The Power track is designed for members who want to build muscle, increase strength, and make measurable progress in their lifts. So, what is RPE in lifting, exactly? It’s how you choose weights that are challenging enough to drive improvement, without compromising your technique.
For strength training, it helps to think of RPE in terms of reps left in the tank:
- RPE 7 – about three reps left.
- RPE 8 – about two reps left.
- RPE 9 – about one rep left.
- RPE 10 – no reps left. You couldn’t do another one with good form.
For your main heavy lifts, aim for RPE 8.5 to 9.5 – near-maximal effort, but with one or two reps still in reserve. If you consistently finish a set below this range with strong form, it may be time to lift heavier. If your technique begins to break down, however, the weight may be too demanding.
Lean: use RPE to manage sustained effort
Our Lean track is for members who want to reduce body fat, build muscle, and use F45 as part of a holistic weight-loss plan. Because these sessions combine resistance and cardio demands, RPE can help you manage your energy and maintain a strong effort throughout your workout.
Aim for approximately RPE 7.5 to 8.5 for most of the session, then build toward RPE 10 during the final push. This keeps your heart rate elevated and supports greater calorie expenditure while helping you maintain a strong effort across every station.
Athlete: use RPE to improve performance
The Athlete track is designed for experienced members who want to improve their speed, power, metabolic conditioning, and overall athletic performance. RPE helps you pace demanding intervals so you can produce high-quality efforts repeatedly.
Try to hold a controlled RPE of 7 to 8 across every interval. As your fitness improves, you’ll notice you can hit that same RPE while running faster or lifting more.
As F45 trainer Jordi Duff explains: “The mistake I see all the time is people treating every interval like it’s the last one they’ll ever do. Athlete training is about consistency under fatigue. I’d rather see someone hold RPE 7 across eight rounds than smash a 10 on round one and crawl through the rest.”
RPE vs heart rate: which should you use?
If you have access to both, it’s worth tracking your heart rate and your RPE side by side – they measure different things, and together they give you a fuller picture of what’s happening in a workout:
- Heart rate is an objective, physiological readout of how hard your heart’s working, measured in beats per minute.
- RPE is subjective and measures how the effort feels, tapping into your mind-body connection.
Your heart rate tells you what your body’s doing, while your RPE tells you how it’s coping – and it’s that combination that gives you the most accurate read on your training intensity.
Now that you know what RPE is, explore the F45 Challenge tracks and find the one that matches the fitness goals you want to achieve.
