Heavy strength work needs roughly three to five minutes between sets — hypertrophy work sixty to ninety seconds, and endurance work thirty to sixty. The rest is prescribed by the goal of the set, not by how recovered you feel.
A near-maximal set is fuelled largely by stored phosphocreatine, and restoring it takes minutes rather than seconds. Cut the rest and the next set is performed with less available fuel, so it is lighter or shorter — which trains something other than what you intended.
It is a band, not a threshold, and it assumes the goal is the set in front of you. Circuit and conditioning work deliberately shortens rest to keep the heart rate up, and for a small isolation movement three minutes is simply wasted time. Feeling ready is also not the test: heart rate settles well before the phosphocreatine does.
Estimate with the rule, then check it against the calculator that models it properly.
Open Gym Companion →Heavy strength work needs roughly three to five minutes between sets — hypertrophy work sixty to ninety seconds, and endurance work thirty to sixty. The rest is prescribed by the goal of the set, not by how recovered you feel. A near-maximal set is fuelled largely by stored phosphocreatine, and restoring it takes minutes rather than seconds.