Chest flies are an excellent isolation exercise for working the chest, with an emphasis on the outer chest. One way to change this move and add intensity is to do this one arm at a time. By doing this, you'll get more work in the core, which has to engage to stabilize your body and keep good form. You may need to go lighter with this version than you do with traditional flies since you won't have the other arm to balance you out.
- Lie down on a bench or step and hold a medium-heavy weight in the right hand.
- Extend the arm up, palm facing in, and brace the abs to hold the body steady on the step.
- Slowly lower the right arm down toward the floor, keeping the elbow slightly bent.
- Lower the arm until it is just level with the step to avoid putting too much stress on the shoulders.
- Squeeze the chest to lift the arm back up and repeat for all reps before switching sides.
- Repeat for 1-3 sets of 8-16 reps.