Here’s a quick guideline on resting between sets:
When you are performing 4-6 reps for one set, you should rest 90 seconds between each set.
When you are performing 8-10 reps for one set, you should rest 60 seconds between each set.
*For sets where you perform 4-6 reps, you should be using heavier weights compared to sets where you are performing 8-10 reps. This is why you will need a longer rest period for exercise sets of 4-6 reps.