Simple Response

Strength Training - 4 to 7 repetitions

Hypertrophy Training - 8-20+ repetitions (AMRAP-1)

*there are no hard and fast rules here but these will serve you well as basic guidelines.

*AMRAP-1 means as many repetitions as possible with one repetition left in the tank.

Goal Dependant

The amount of repetitions you perform on the dumbbell bench press will depend on your training goal. If you are looking to gain in muscle or gain in strength then the repetitions ranges will be different. Strength training and hypertrophy training are never mutually exclusive, in the sense that if you do one it doesn’t effect the other, of course it does. That being said there are still optimal repetition ranges for each goal.

Strength Training Repetitions

Training strength with the DB bench press can be a little awkward as the start position can be hard to find with heavy weights. However strength training can still be done with the DB bench press, I would usually perform 4-7 repetitions for strength in the DB bench press. Anything less than four repetitions would usually be challenging to get into the starting position. If this isn’t the case for you then feel free to perform less than 4 repetitions in strength development, just pay extra attention to make sure you are finding the start position is a safe way. The goal of strength training is really simple, lift something you find heavy for minimal repetitions.

Hypertrophy Repetitions

The DB bench press really comes into its own for training hypertrophy. The goal for hypertrophy training is to accumulate high levels of fatigue and train close to failure on most sets performed. Hypertrophy can be anything from 8-20+ repetitions. The key really is that you accumulate high levels of fatigue, meaning that if you perform 20 repetitions and could perform much more repetitions then this is not effective training. When performing hypertrophy sets, do not prescribe specific repetitions, select a weight where you can perform more than 8 repetitions and then perform an AMRAP - 1. AMRAP - 1 means as many reps as possible with one repetition left in the tank. This will be highly effective for hypertrophy training.