Finding the Perfect Resistance for Strength Training Based on One Rep Max and RPE Guidelines

Richard Punzenberger
Jan 3
4 min read

Strength training is most effective when you use the right amount of resistance. Too little weight, and your muscles won’t be challenged enough to grow stronger. Too much, and you risk injury or burnout. Understanding how to select the right resistance involves knowing your one rep max (1RM), how to adjust percentages of that max for different training phases, and how to use the Rate of Perceived Exertion (RPE) to fine-tune your effort and rest periods. This guide breaks down these concepts and shows you how to apply them to your workouts for steady progress.

What Is One Rep Max and Why It Matters

Your one rep max (1RM) is the maximum amount of weight you can lift for a single repetition of a given exercise with proper form. It’s a key benchmark in strength training because it represents your current maximum strength level for that movement.

Knowing your 1RM helps you:

Set realistic training loads
Track progress over time
Prevent injury by avoiding weights that are too heavy
Structure your workouts based on specific goals

How to Find Your One Rep Max Safely

Testing your 1RM can be done in a few ways:

Direct testing: Warm up thoroughly, then gradually increase weight until you find the maximum you can lift once without losing form. This method is accurate but can be risky for beginners or those with injuries.
Estimated 1RM: Use submaximal lifts and formulas to estimate your 1RM. For example, if you can lift 100 pounds for 5 reps, you can estimate your 1RM using a formula like:

This method is safer and practical for most lifters.

Using Percentages of One Rep Max for Different Training Phases

Once you know your 1RM, you can plan your training by selecting weights based on percentages of that max. Different phases of training require different intensities and rep ranges.

|---------------------|----------|---------------------|---------------------------------|

| Strength | 85-95% | 1-5 | Build maximal strength |

| Hypertrophy | 65-85% | 6-12 | Increase muscle size |

| Muscular Endurance | 50-65% | 12-20+ | Improve stamina and endurance |

Example: Planning a Strength Phase

If your 1RM for the bench press is 200 pounds, training at 85-95% means using weights between 170 and 190 pounds. You would perform sets of 1 to 5 reps with this load, focusing on lifting with maximum effort and proper form.

Understanding RPE and How It Relates to Resistance and Rest

The Rate of Perceived Exertion (RPE) is a subjective scale that measures how hard you feel you are working during an exercise. It helps you adjust your training intensity based on how your body feels, rather than relying solely on numbers.

The RPE Scale for Strength Training

The RPE scale typically runs from 1 to 10:

1-3: Very light effort, easy to maintain
4-6: Moderate effort, can continue for a while
7-8: Hard effort, close to fatigue but can still perform a few more reps
9: Very hard, only 1 rep left in the tank
10: Max effort, no reps left in reserve

How to Use RPE with Resistance

Instead of always lifting a fixed percentage of your 1RM, you can adjust the weight to hit a target RPE. For example, if your goal is to train at an RPE of 8, you choose a weight that feels challenging but leaves you with about 2 reps in reserve.

This approach allows you to:

Adapt to daily fluctuations in strength
Avoid overtraining by respecting fatigue
Progress safely by increasing weight only when RPE drops

RPE and Rest Periods

Your rest time between sets should also reflect your RPE and training goals:

Higher RPE (8-10): Longer rest (2-5 minutes) to recover strength for the next heavy set
Moderate RPE (5-7): Moderate rest (1-2 minutes) to maintain workout pace
Lower RPE (1-4): Short rest (30 seconds to 1 minute) for endurance or warm-up sets

Eye-level view of a barbell loaded with weights on a gym rack — Barbell loaded with weights on gym rack, demonstrating proper resistance setup

Practical Tips for Finding the Right Resistance

Here are some actionable steps to help you find the perfect resistance for your strength exercises:

Start with an estimated 1RM if you’re new or unsure, then adjust based on how you feel during sets.
Use percentages of your 1RM to plan your training phases and set rep ranges.
Incorporate RPE to fine-tune your effort and avoid pushing too hard or too little.
Track your progress by recording weights, reps, and RPE after each workout.
Adjust rest periods based on your RPE and training goals to maximize recovery and performance.
Listen to your body: If a weight feels too heavy or too light, adjust accordingly rather than sticking rigidly to numbers.

Examples of Resistance and RPE in Different Exercises

Squat Example

1RM: 300 pounds
Strength phase: 85-95% → 255-285 pounds, 3-5 reps per set
RPE target: 8-9 (leaving 1-2 reps in reserve)
Rest: 3 minutes between sets

Dumbbell Curl Example

Estimated 1RM: 40 pounds (single-arm)
Hypertrophy phase: 65-75% → 26-30 pounds, 8-12 reps
RPE target: 7-8
Rest: 1-2 minutes between sets

How to Progress Over Time

As you get stronger, your 1RM will increase. This means you need to:

Re-test or estimate your 1RM regularly (every 6-8 weeks)
Adjust your training weights based on the new 1RM
Use RPE to guide daily adjustments when you feel stronger or more fatigued
Increase weight gradually when your RPE drops below your target for a given set and rep range

Real progress starts with the right plan—and the right support.

With Punzy Fitness, you’ll get weekly coaching, personalized movement assessments, and clear next steps tailored to your goals.

👉 Apply for online coaching and start moving better, feeling stronger, and living healthier.

Disclaimer:

The information shared in this article is for educational purposes only and is not a substitute for professional medical advice. Always consult with your healthcare team before beginning a new exercise program, using supplements, or making dietary changes, especially if you have existing health conditions.