Fire and Iron Lifting Tip

Apr 13, 2024

 by Lisa MacLeod

Let's talk about the Rate of Perceived Exertion scale and how we can use it to guide our weight loading choices for effective strength training.  Here is a brief description to pre-load your understanding.

The Rate of Perceived Exertion scale or RPE is a subjective measure of how hard you feel you are working during any physical activity.  When you use this scale you are rating the perceived difficulty of an exercise based on the physical sensations you are experiencing, such as increased heart rate, increased respiration, sweating, and overall muscle fatigue. The scale goes from 1-10 and looks like this:

When we use this scale for strength training we are rating the intensity of our effort used to perform an exercise at a certain weight for a given number of reps.   When you are performing at an RPE of 10, this is your absolute max effort where you can not perform another rep at that weight.  When you are at an RPE of 9, maybe you could have performed 1 more rep.  At an RPE of 8, you likely could have performed 1-2 more reps.  At an RPE of 7, you could have performed 2-3 more reps, and so on. 

So, where should you be at on the RPE scale to maximize your strength-building potential? 
The answer is an RPE of 7-8 for your working sets.  When you hit this sweet spot, some amazing things are happening physiologically in your body.  By lifting heavy weights you are elevating levels of anabolic hormones that stimulate muscle growth and repair, such as insulin-like growth factor, growth hormone, and testosterone. And guess what?  These are the same hormones that as we age and experience perimenopause/menopause naturally decline, and a decline in these hormones has been shown to lead to reduced muscle mass and function.  So by lifting heavy, at an RPE of 7-8, we are helping our bodies elevate the levels of hormones that will keep us strong and able as we age and experience our “second spring.”

Lastly, working at an RPE of 7-8 creates enough challenge to produce the physiological effect of muscle growth and strength gains, without over-fatiguing the muscles and prolonging recovery. 

The take-home is this:  RPE can be an effective tool to help you hone that sweet spot and maximize the effects of strength training, especially as you get more experienced in self-rating your effort.  Paying attention to your weight loads and your efforts will help you make the most of your Fire & Iron experience.