The iso-lateral incline bench press is commonly performed on a machine that’s available at many fitness gyms. Typical incline bench press machines are constructed so that your arms work together to push the unit arms away from your chest. The iso-lateral unit, however, has each unit arm moving independently. You can mimic this exercise by using a pair of dumbbells.
Before beginning the exercise, adjust the weight bench so that it’s set at an incline position. Grip a pair of dumbbells and hold them onto your thighs as you sit on the bench. Lean back against the bench and place your feet firmly on the floor. Lift the dumbbells so that they’re set just above your chest with your palms facing forward. Exhale and press the dumbbells up over your head until your arms are fully extended. Inhale as you control the weights back to starting position.
Iso-lateral dumbbell incline bench press primarily develops the upper area of your pectoralis major, which is the largest muscle at your chest. Your pectoralis major performs transverse flexion and transverse adduction, meaning it brings your arms up and in toward the centerline of your body. Your deltoids, which are the major muscles in your shoulders, are also recruited to contribute to flexion and adduction. The triceps brachii muscle at the back of each of your upper arms, contracts to straighten your elbows as you push the weights overhead. The more reclined the bench, the more that you target your chest muscle. A more inclined bench will place greater emphasis on your shoulders.
The iso-lateral dumbbell incline bench press is also commonly referred to as simply dumbbell incline bench press. The iso-lateral term refers to each arm moving independently, which when working with dumbbells is always the case. If you were to perform incline bench press with a barbell or most machines, both arms work together to lift the weights. This means that your more dominant limb can take on a major of the work, which will then limit the development of the weaker limb. Performing the exercise iso-laterally makes each limb take on the same amount of work.
Performing iso-lateral incline bench press with dumbbells also allows you to add variety to the exercise. You can perform the exercise one limb at a time, which will increase the amount of muscle fibers of your chest, shoulders and triceps that are recruited. Plus, because performing the exercise one arm at a time increases instability, more surrounding stabilizer muscles around your chest become involved to help coordinate the movement.
Kim Nunley has been screenwriting and working as an online health and fitness writer since 2005. She’s had multiple short screenplays produced and her feature scripts have placed at the Austin Film Festival. Prior to writing full-time, she worked as a strength coach, athletic coach and college instructor. She holds a master's degree in kinesiology from California State University, Fullerton.