Tracking Intensity in Resistance Training: Understanding the Benefits and Limitations of RM%, RIR, and RPE

When it comes to keeping track of the intensity during resistance training, personal trainers need to be well-versed in the different methods available. Three of the most commonly used methods are Repetition Maximum Percentage (RM%), Repetitions in Reserve (RIR), and Rate of Perceived Exertion (RPE). Each of these methods has its own advantages and disadvantages, and it’s essential to know when to use them effectively.

Repetition Maximum Percentage (RM%)

RM% is a way of measuring intensity based on the maximum weight a client can lift for a set number of repetitions. For example, if a client can lift a weight 10 times, that weight becomes their 10-rep max (10RM). From there, you can calculate their 5RM, 3RM, and 1RM, which can then be used to monitor their resistance training intensity. This method is best for tracking intensity in strength training and powerlifting programs.


Reps in Reserve (RIR)

On the other hand, RIR looks at the number of repetitions a client can perform before they hit failure. If a client can perform 10 reps with a weight but could have done 12, they have 2 repetitions in reserve. This method is useful for keeping track of intensity when working with clients who want to improve their muscular endurance or focus on hypertrophy training, as it helps make sure they are working at the right intensity level.

Rate of Perceived Exertion (RPE)

RPE measures intensity based on the client’s personal feelings about the level of effort they are putting into each exercise. The RPE scale ranges from 1 to 10, with 1 being the least intense and 10 the most intense. This method is ideal for tracking intensity for clients who want to improve their overall fitness and cardiovascular health.

It’s important to remember that each method has its own strengths and weaknesses, and the best method for you will depend on your client’s goals and objectives. RM% is fantastic for strength training and powerlifting, RIR is great for muscular endurance and hypertrophy training, and RPE is perfect for clients looking to improve overall fitness and cardiovascular health. Another point to consider is what is the demographic you are training e.g. an older client with little experience may feel more comfortable with RPE as opposed to RM% or RIR. Which one you use will depend on the circumstances.

In conclusion, as a personal trainer, it’s crucial to have a good understanding of the various methods for tracking intensity in resistance training. No matter if you choose RM%, RIR, or RPE, it’s essential to pick the method that fits your client’s goals and objectives. By doing so, you can make sure they are working at the right intensity level, progress towards their fitness goals, and reduce the risk of injury.

Author: Michael Lea, Onfit Education Team