When it comes to getting stronger, building muscle, or just staying consistent with your fitness goals, training intensity matters. Two of the most effective and beginner-friendly ways to measure how hard you're working in a workout are the RPE (Rate of Perceived Exertion) and RIR (Reps in Reserve) scales.

What is RPE?

RPE stands for Rate of Perceived Exertion. It’s a 1–10 scale that helps you gauge how hard an exercise feels.

• RPE 1–4 = light activity or warm-up

• RPE 5–6 = moderate effort, still able to hold a conversation

• RPE 7–8 = challenging but sustainable effort

• RPE 9–10 = near-maximal or maximal effort (very few or no reps left in the tank)

For most strength and hypertrophy (muscle-building) training, you’ll often aim for RPE 7–9. This ensures you’re working hard enough to make progress, without burning out or risking injury.

What is RIR?

RIR means Reps in Reserve - a simple way to estimate how many more reps you could’ve done before failure.

• If you finish a set and feel like you could do 2 more reps, that’s RIR 2.

• If you went to failure and couldn’t do any more, that’s RIR 0.

RIR helps fine-tune your training by making sure you’re pushing enough to create results, but not so hard that recovery suffers. It also pairs well with RPE (e.g., RIR 2 = RPE 8).

Why Use RPE and RIR in Your Workouts?

Using RPE and RIR makes your training smarter and more personalized, especially as your strength, energy, or stress levels change from day to day.

Bottom line: RPE and RIR are great tools to give you the feedback you need to train with the right intensity for your goals. Most people don’t push hard enough to realize their true RIR, so this is something we will review often during our training.