CALL US TODAY (608) 218-4215

5 Ways to Find a 1 Rep Max

Building strength and putting on muscle is the number one way to mitigate risk of injury. It builds resilience. To get the desired outcome of strength, load is required. Many strength building programs base that amount of load on a person’s 1 rep max. A 1 rep max is the most amount of weight a person can perform a movement without failing. A common strength building prescription is 5 sets of 5 at 80% of your 1 rep max. But to lift 80%, we need to know what our 100%, or 1 rep max, is

Here are 5 different ways to find a 1 rep max:

  1. Find a true 1 rep max. This is the most accurate method but should be used for experienced lifters. Warm up and continue to add load until you find that max. The downfall to finding a true 1 rep max is that it is time consuming and requires a spotter for safety.
  2. Establish a 5, or 10 rep max. Performed that same way as finding a 1 rep max but with less weight and more repetition. This is a good option for someone with limited access to weight or are hesitant to be under a 100% load. 5 rep max = 90% of 1 rep max. 10 rep max = 75% of 1 rep max.
  3. Use a 1 rep max calculator (like this one- One Rep Max Calculator – Strength Level). With this method, find a moderate weight and perform as many repetitions as possible before failure. Then you enter the weight lifted, and number of repetitions into the calculator and it will calculate an estimated 1 rep max. For example, lifting 160 lbs for 12 reps will give an estimated 1 rep max of 224 lbs.
  4. Rate of Perceived Exertion (RPE). This is a 1-10 subjective scale that corresponds with a percentage of 1 rep max. An individual performs a lift, then rates their effort level from 1 (extremely easy) to 10 (maximum effort). A 10 would equate to 1 rep max, 8 = 80% and so on.
  5. Repetitions in Reserve (RIR). RIR is another subjective measure and relates closely to RPE. After doing a set of an exercise, an individual assesses how many more repetitions they could have continued for before failure and this is their “reps in reserve”. For example, an individual performs a set of 5 back squat and feel they could have performed 4 more reps before they would fail or use form. Their reps in reserve is 4 which equates of a 6/10 RPE (see chart below). For a 5×5 strength session at 80% of 1 RM, the RPE should be 7-8/10 or 2-3 reps in reserve.

After you have found your true or estimated 1 rep max, you can use it to calculate your prescribed percentages for lifting. The more accurate you can be with the appropriate load, the more effective your weight training session will be.

Happy lifting!
Our Mission:

Here at Peak Endurance Performance & Physical Therapy we help active adults in the Madison Area get back to the activities they love without pain or limitations. We see people of all ages, ability levels, and individuals trying to get back to a multitude of movements including: getting back into running, women postpartum, CrossFit athletes, climbers, gymnasts, wrestlers, overhead athletes, and your recreational weekend warrior. If you’re looking to get back to the activities that give you meaning, relieve stress, and make you feel like you again, feel free to reach out below and we’ll see if we’re the right fit for you.