Isolation, or single-joint, exercises like curls, lateral raises, and flys have gotten a bad rap of late. Functional training purists are quick to deem them non-functional, relegating them to bodybuilding protocols only. While the focus of training should always be on big multi-joint movements, isolation training is often the best strategy for strengthening synergists, regressing multi-joint exercises, and activating “sleepy” muscles. For this reason, most everyone’s training will benefit from the inclusion of a few select isolation movements. In analogy to food, after you’ve eaten your meat and potatoes (compound lifts), you should feel free to indulge in a bit of dessert (isolation lifts). Of course, if you’re going to eat dessert, you want to make sure it’s worth it. Like adding chocolate syrup to vanilla ice cream, a slight tweak to the way in which an exercise is traditionally performed can confer a drastically greater benefit. Below are six such tweaks.
1. Cable fly (pecs)
Traditionally performed with dumbbells, chest flys provide an extremely poor resistance profile. Since gravity acts straight down, during the concentric phase of the fly the moment arm (horizontal distance from the dumbbell to the shoulder) shortens to zero, resulting in no resistance at the end range. A better alternative is to use cables instead of dumbbells. By fixing the pulleys a few notches above the floor, the cables provide more consistent tension in opposition to the pecs throughout the entire movement.
Traditionally performed with a fast tempo in a bent-over position, stiff-arm pull-downs hit the lats and triceps hard but do little for the core. By switching to an erect posture with an eccentric emphasis (4-count on the way up), the anterior core gets recruited heavily to prevent lumbar hyperextension. Reverse directions as soon as the arms reach parallel to the floor in order to maintain constant tension.
Traditionally performed with purely elbow flexion in mind, bicep curls can be enhanced in two ways. Since the biceps also supinate the forearm, taking an offset grip on the dumbbell by moving the thumb and index finger right up to the edge of the handle will increase the supination demand. In addition, performing curls from a seated position on an incline bench with a small degree of shoulder flexion will add additional tension on the long head of the biceps. Begin by curling both arms at the same time. To squeeze out a few extra reps at the end of the set, alternate arms.
Traditionally performed with the upper arm perpendicular to the floor, the skull crusher can be intensified by maintaining a greater degree of shoulder flexion throughout the movement. The additional shoulder angle will aid in the recruit of the long head of the triceps and likely necessitate the use of lighter weights initially. Do not allow the dumbbells to touch each other at any point.
5. Constant tension lateral raise (delts)
Traditionally performed from 0 to 90 degrees, lateral raises target the delts more effectively at the end range of the movement due to moment arm length as well as contributions from the rotator cuff. To maintain more constant tension on the delts, simply perform only the latter two-thirds of the motion (30 degrees to 90 degrees of abduction).
6. Bodyweight glute bridging with band abduction (glutes)
Traditionally performed with bodyweight alone for resistance, adding a mini-band around the knees intensifies glute activation by incorporating hip abduction in addition to hip extension. Maintain constant outward tension on the band during the entire set, or simply push the knees out against the band as you raise your hips.
