For strength and muscle on little time, this narrative review recommends at least 4 sets per muscle group a week at 6-15 RM (or 15-40 reps taken to failure), from at least one leg-pressing exercise such as a squat, one upper-body pull and one upper-body push; in the authors' view weekly volume counts for more than frequency, supersets, drop sets and rest-pause roughly halve training time (probably better for muscle size than strength), and stretching is for flexibility goals only

Iversen and colleagues start from lack of time, among the barriers people report more often for not exercising, and review research on training variables, advanced techniques, warm-up and stretching to work out how strength training can be done in the least time.

They advise bilateral, multi-joint exercises with full dynamic movements, lowering as well as lifting, and at least one leg-pressing exercise (such as squats), one upper-body pull (such as pull-ups) and one upper-body push (such as bench press), on machines or free weights as goals, access and preference allow.

In their reading weekly volume matters more than how often one trains, and the minimum they set is 4 weekly sets per muscle group at 6-15 RM, or 15-40 repetitions when sets are taken to volitional failure.

Supersets, drop sets and rest-pause training take roughly half the time of traditional sets at the same volume, but probably favour muscle growth over strength, and their long-term effects need more study. Warm-ups can be limited to the exercises themselves, and stretching earns its time only when flexibility is the goal.