Using partial repetitions or playing with tempo in resistance training makes consistent progression difficult to track.

“The problem with doing partial repetitions or even playing with tempo is that it's really difficult to replicate consistently. And so I mentioned earlier that we want to progress over time. And if we're standardizing the range of motion and we're standardizing the exercise and we're standardizing the tempo, then it's easy to say, "Okay, I'm using 2 and a half more pounds this week. I've progressed." If we're playing around with all of these variables and then we're trying to add load, it starts to get a little tricky because you're saying, I know I'm using more load, but am I cutting the range of motion short in order to to to lift more? Uh am I speeding up the reps in order to lift more?