While getting stronger, you have to realize that high intensity, by nature, is more strenuous for the nervous system and thus, requires more rest times between sets.
While the bodybuilding rep range only requires rests of ~3 minutes for you to sustain performance from set to set, the 1-5 rep range requires 5-15 minutes between sets.
For this reason, one of the main character traits that this challenge requires is patience!
Remember that leaving enough window for recovery both in-between sets and the separate workouts, is essential in order for you to maximize performance and decrease the risk of injury.
Course: Get Strong Challenge – The Big 3