Chart is based off of the ‘above average’ athletes. The numbers presented should be adjusted to fit the appropriate effort within the time domain based on the particular workout, athlete, and stimulus.
Chart is based off of a moderate to moderate-high effort “in a workout”. This is not necessarily meant to be a max effort substitution chart or a perfect 1:1 comparison based on the different modalities.
The primary goal in creating meaningful substitutions for athletes should always be trying to match the desired time domain with the desired level of effort in that time while considering the workout.