The short answer
Most effective strength sessions last 45 to 75 minutes, warm-up included. The length follows from the number of sets and the rest between them; it is not a goal in itself. With 30 minutes you can still train well by choosing fewer exercises and pairing them; past 90 minutes, the last sets are often less productive.
The duration follows the sets
Count the sets in your session and the rest between them. Example: 16 sets × (40 s of effort + 2 min of rest) is about 43 minutes. Add 10 minutes of warm-up and you get a little under an hour.
What a typical session contains
A warm-up of 5 to 10 minutes, two or three compound exercises (squat, bench press, row) with longer rests, then two or three isolation exercises with shorter rests. That makes 45 to 75 minutes for most programs in this library.
Short on time? Here is where to save it
Pair two exercises that do not use the same muscles, such as a press and a row, and alternate them: one muscle rests while the other works. Keep the main lifts, cut extra isolation work, and rest a little less on small exercises.
Are longer sessions better?
Not necessarily. After about an hour of hard work, the quality of the sets tends to drop. If your session regularly goes past 90 minutes, split it in two or remove an exercise.
Time one session
Log a full session with its rest periods. You will see where the time goes: often rests that run long, or time spent between exercises.
Put it into practice
About this guide
STARK editorial guide. Examples explain how to use the library and record training; they are not individual coaching.
Training principles: ACSM — Resistance Training Guidelines (2026).
The session examples come from the STARK program catalogue linked above.