Rest long enough to perform the next set well. The right interval depends on the exercise, effort and goal.
Heavy movements need more recovery
Squats, deadlift variations, presses and rows can require two or three minutes when the sets are challenging. The muscles, breathing and concentration all need time to recover.
Starting the next set too early may reduce repetitions or force technique to deteriorate.
Smaller exercises need less
Curls, lateral raises, calf raises and many machine exercises often work well with shorter rests. Sixty to ninety seconds may be enough when the load is moderate and the movement is stable.
Use performance as the guide rather than obeying the clock blindly.
Supersets can save time
Pair exercises that use different muscle groups, such as a split squat with a row or a press with a hamstring curl. While one area works, the other gets additional recovery.
Avoid pairing two movements that compete heavily for the same muscles if strength is the priority.
A practical rule
Begin the next set when your breathing is under control, your technique feels repeatable and the target muscles are ready to produce useful effort. Take longer when the next set matters more.
Efficient training removes wasted time, but it does not remove the recovery required for quality work.
This article provides general education and does not replace individualized medical care. Speak with an appropriate healthcare professional before beginning exercise if you have symptoms, significant health concerns or medical restrictions.