Understanding Strength: Intensity

Posted by Michael Shaughnessy on

Welcome to Understanding Strength, our ongoing series that defines different terminologies, concepts, and techniques that you may encounter in a strength training environment.


This word may evoke imagery of someone entering an empty gym in the early hours of the morning and banging out a session worthy of a Rocky montage, but in reality, Intensity is just a metric to show how much work is being done by an individual during exercise. 

Intensity is typically expressed using a percentage and can have different meanings depending on the context of the person training. For example, a weightlifter or a powerlifter would express this using a percentage of their one rep max (1RM), and a sprinter would express this as a percentage of their maximum speed (m/s or their own perceived effort). While the units are different, they still express the same thing; how hard the individual is working during exercise.

For a strength athlete, Relative Intensity and Absolute Intensity are also important factors to consider. 

Relative Intensity

Relative intensity is a way of quantifying how hard you should feel like you are working. This seems confusing at first, but it makes sense if we take a look at a rep max chart, which shows on average the maximum amount of reps a lifter can perform with a percentage of 1RM.

 Number of Repetitions Performed Percentage of 1RM





















 Chart from Essentials of Strength and Conditioning 4th Edition 

To determine the relative intensity of a workout we compare the intensity of the working sets compared to what should be a maximum effort for those sets.

Let's use a basic example of a session: 5x5 at 75% 1RM.

Now according to the chart, the percentage of 1RM that would be on the bar for a maximum effort set of 5 would be 87%. Now we can use this calculation to work out the relative intensity:

0.75 (% of 1RM) / 0.87 (Rep max for 5) = 0.86

So that workout has an 86% relative intensity

Keeping an eye on relative intensity can help ensure not just that your workouts are getting harder and ensuring Overload (more on this in another article), but making sure the difficulty does not jump too quickly from session to session.

Absolute Intensity

Absolute intensity, on the other hand, refers to the actual weight on the bar, regardless of the lifter's 1RM or relative intensity. 

So if you were to take two lifters, one with a squat max of 200kg, and another of 400kg. Now if they both had a workout with 70% 1RM, the 200kg lifter would be using 150kg, and the 400kg lifter would be using 300kg. So, while the workout would be of equal intensity relative to 1RM, the 400kg Squatter would be using a higher absolute intensity.

A higher absolute intensity can affect the length of recovery time and the frequency that this intensity can be trained at, which are extra considerations that need to be taken as a lifter gets stronger.

Take Home Points

  • Intensity is the metric that tracks how hard you work during training
  • Relative Intensity = how hard that work should feel
  • Absolute Intensity = how hard you are working relative to others


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