Originally Posted by Fedornumber1!
What does he mean by strength over time?
He probably means strength endurance (which you train with lower weights, but a higher number of repetition) as opposed to maximum strength or hypertrophy (which you train with highest/high weights, but a low number of repetitions).
In fighting you need primarily strength endurance to prevent your muscles from tiring quickly, because fights usually are longer than ~20 seconds which is about the timespan you can use your muscles at maximum strength. That has something to do with the lactic acids that are build as a byproduct while muscle work. If you're interested search for unaerobic and aerobic metabolism.