As I explained in last week’s article, the whole reason for prescribing a set number of reps with a set weight is so that we can measure what our body is currently capable of and slowly increase that.
It may have been Arnold Scwarznegger who first said the last rep in a set gives you the gains. Scientifically speaking this isn’t 100% correct, but it is still a valid concept to consider in terms of motivation.
In order to challenge muscle and elicit growth, you need to subject it to more work than it is used to. This sends a message to your body that basically says, “Hey, if we’re going to be asked to do this time and again, we’ll need to be bigger and stronger so we don’t get injured!’.