Rest periods between sets of strength training or circuit training is one of the most important variables you can manipulate in your training program to achieve the results you desire. Ultimately it all depends on what energy systems your training. This can get very technical but I’ll try to keep it simple.
If your primary goal is maximal strength, a 1 minute rest period will not allow that energy system to recover before the next set, and it would suck! I would allow for at least 3 minutes to upwards of 10 minutes depending on how close your working to your 1 rep max, how strong you want to get or the exercise (for example deadlifts take longer to recover from than military presses. To lift maximal weights efficiently you must be fully recovered.
If your goal is bodybuilding (hypertrophy), rest periods of 1-2 minutes are sufficient. You would typically be using weights in the 60%-80% of your 1 rep max and a rep range of around 8-20. The volume of total work is the major factor in a bodybuilding program, not lifting as much weight as you can (usually). Not that its gonna hurt a bodybuilder to lift heavy and get stronger.
If conditioning and fat loss is the goal, I suggest the rest periods to be anywhere from next to nothing to upwards of 2 minutes or so depending on the type of training. Different types of conditioning and circuit training will require different rest periods that are dependent on the intensity.
Some types of training don’t allow for any set rest periods (ie. metabolic resistance training) and your body will basically jump around from energy system to energy system. If your a long distance runner you will need to work well under maximal levels to maintain a consistent aerobic pace instead of working in the anaerobic zones.
We are constantly learning and implementing new programming. None of this is set in stone, but based on current research, hopefully this info can help you set up an effective program for yourself.
Strength For Life