Are Shoulder Presses and Curls at the Same Time a Bad Idea?

A combination exercise is two exercises combined together into one continuous movement. Many exercises can be combined, such as presses and squats, lunges and extensions, and curls and presses. Combination exercises, such as the shoulder press and curl, reduce the total workload and duration of a workout, but they also have drawbacks that may outweigh the benefits.

Hold one dumbbell in each hand with your arms relaxed by your sides and your palms facing forward. Lock your upper arms into your sides and curl the dumbbells up to your shoulders. Continue the movement by pressing the dumbbells overhead, rotating your wrists so your palms face forward when your arms are fully extended overhead. Pause for a count, slowly lower the dumbbells back to your shoulders and then uncurl the weights, returning to the starting position.

The curl shoulder press combination exercise works several muscle groups in the upper body. The arm curl, an isolation exercise involving only one joint, targets the biceps muscles. The shoulder press, a compound movement involving more than one joint, works several muscles, including the front shoulder, side shoulder, triceps and trapezius muscles.

Performing the curl and press exercise simultaneously saves time in the gym. It reduces the total number of sets in a workout and eliminates some of the downtime between sets. If a workout routine calls for doing three sets of shoulder presses and three sets of biceps curls -- for a total of six sets -- you can reduce this to three sets of the combination exercise, eliminating three of the sets and the rest time between those three sets.

Depending on your strength levels, the same weight may not be appropriate for both exercises. The biceps work alone during the curl exercise, but several muscles work together during the shoulder press exercise. More weight is typically needed to fatigue the shoulder press muscles than the arm curl muscles. If you choose a weight that fatigues the biceps in 10 repetitions, the shoulder press may feel too easy. If you choose a weight that fatigues the shoulder press muscles in 10 repetitions, you may struggle to complete the biceps curls.