Strength, Size or Endurance?

Different goals requires different repetitions:

- Strength: 2-6 reps @ 90% of one rep max.

- Hypertrophy: 7-14 reps @ 75% of one rep max.

- Endurance: 15-20 reps @ 50% of one rep max. This increases storages of phosphocreatine and ATP

As far as sets go, 2 hard sets with good form will be equivalent to 3 sets that most people do.