I’ll make this statement first which will become clearer to all as you read further. Bodybuilding is a muscle sport, where weightlifting is a nervous system sport. Now let’s move on to the rest intervals between sets.
The recovery of one’s power output is relative to one’s rest intervals between sets. This is more imperative in weightlifting than it is in bodybuilding I feel.
Recovery Time of 15 sec = Peak Power Output of 68.7%
30sec--------------73.6%
45sec--------------78.1%
60sec--------------81.0%
120sec-------------88.2%
180sec-------------92.2%
http://www.brianmac.co.uk/energy.htm
One has to be mindful of his chosen sport’s requirement when it comes to rest intervals between sets. For example, a weightlifter (as I’ve stated above) is interested in lifting big instead of looking big. A bodybuilder on the other hand ought to be concerned with the way he looks above what he can lift. What determines the rest factor is the sport.
Weightlifters need between 3-5 minutes rest between sets, and they usually take them whilst sitting down. Bodybuilders need less time to recover since their repetitions do not call for anything below the 5 reps mark (where neural drive is the dominant factor, i.e. plenty of pressure on the CNS). Muscles can replenish their energy enough to smash another set within 60-90 seconds of rest intervals.
Furthermore, a bodybuilder would not want to wait until full recovery has been reached before diving into another set… why? Because you want the muscle to cry from your applied effort, and one way for that effort to be realised would be for you to take just enough time to recover your working muscles. I mentioned that over here:
Fadi on muscle fibres & more...
So in a nutshell, higher reps exhaust the muscles of their available fuel, whilst low and heavy reps mainly overload the CNS. Now you know why I made the first statement I did in regards to these two different sports.
Every bodybuilder would agree on one universal method, and that is the method of gradual progressive overload. Well, one of the overload method is playing with the time factor instead of (as usually is the case) the adding of more weight to the bar. Overload should not be understood as the adding of more weight all the time (although weight is but one part of overload), but in addition, the time factor between sets is just as important within the overload principle as the gradual weight increase one makes as time passes by.
Example:
Week 1: barbell curling 40kg 4x8 with a rest interval of 90sec
Week 2: same weight same reps but 75 sec rest
Week 3 or 4: same weight same reps with 60 sec rest
Week 5: as above but with 45 sec
Week 6, 8, or 10: as above but with 30 sec
Once 30 sec is reached, you increase the weight by 2.5kg and start again with 90sec. That was time factor overload.
Fadi.