Author: Dr. Gregg Mallett

I often hear from those who train I wish I had a GPS device to monitor my workouts and progress. Well, expensive GPS devices may not be needed to do so. Also, I often see people simply write down what they lifted after a particular set. This is good and all, but what does it mean? What do you do with this information? How do you measure progress? Are you weaker if you do not lift the same weight the next time around? Let us take a look at the metrics of volume (V) and rating of perceived exertion (RPE). This commentary will provide methods to use that can assist in the quantification a workout session and provide meaning.


Variation in the volume of resistance exercise can be a potent stimulus for positive adaptations. Volume (V) is determined by the number of sets (S) multiplied by the number of repetitions (R) multiplied by the weight (W) used for that set.1,2 Simply, V = S x R x W. Volume can be calculated for a specific exercise and/or for the entire session. Instead of considering the sets and repetition ranges of a workout, one should really be focused on daily training volume. Training volume is a better tool when trying to gage the demands of an individual training approach or workout.


Rating of Perceived Exertion (RPE) is a used to subjectively quantify an individual’s perception of the physical demands of an activity. The most widely used RPE tool is the Borg scale, a psychophysical, category scale with rating ranges from 6 (no exertion at all) to 20 (maximal exertion).3 The Borg scale has demonstrated reliability and validity in healthy, clinical and athletic adult populations, such as against heart rate (r = 0.80–0.90).4 The session rate of perceived exertion (sRPE) is performed by multiplying the training session duration (minutes) by the training intensity, indicated by the RPE through the scale adapted by Borg et al.6

Analysis and Application

So now I have two numbers, one relates to volume and one relates to intensity of a resistance training session. Now what? These two numbers can easily be graphed and a relationship can be calculated based off linear regression analysis. Regression analysis is a statistical technique for determining the relationship between a single dependent (criterion) variable and one or more independent (predictor) variables.5


Therefore, a resistance training session and program can be quantified and assessed for progress with the use of a pencil and paper. Sophisticated equipment is not necessarily needed. Instead of tracking sets and repetitions, an approach such as this may provide a more thorough analysis of a resistance training program.


  1. Haff GG, & Triplett NT. Essentials of Strength Training & Conditioning, 4th Ed. Champaign, IL: Human Kinetics; 2016:462-463.
  2. Giessing J, Eichmann B, Steele J, Fisher J. A comparison of low volume ‘high-intensity-training’ and high volume traditional resistance training methods on muscular performance, body composition, and subjective assessments of training. Biology of sport. 2016;33(3):241-249.
  3. Ritchie C. Rating of Perceived Exertion (RPE). Journal of physiotherapy. 2012;58(1):62.
  4. Chen MJ, Fan X, Moe ST. Criterion-related validity of the Borg ratings of perceived exertion scale in healthy individuals: a meta-analysis. Journal of sports sciences. 2002;20(11):873.
  5. Palmer PB, O’Connell DG. Regression analysis for prediction: understanding the process. Cardiopulmonary physical therapy journal. 2009;20(3):23-26.
  6. Noble BJ, Borg GA, Jacobs I, Ceci R, Kaiser P. A category-ratio perceived exertion scale: relationship to blood and muscle lactates and heart rate. Medicine and science in sports and exercise. 1983;15(6):523-528.

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