Your rest interval should, in no instance, be less than three minutes between each set of heavy lifting. (fitnessandpower.com)
Do 4 - 6 sets of each compound exercise and rest about one to two minutes between sets so that you are able to do the next set with approximately the same intensity. (fitnessandpower.com)
The participants recovered for four minutes between sets with either passive sitting or low - intensity exercise on a stationary bicycle. (ironmanmagazine.com)