Cross-Educate Your Muscles Using Unilateral Training

BY AMY ASHMORE, PHD
AUGUST 2020

Unilateral exercises are one-legged or one-armed movements. The primary benefit of including unilateral exercises in your training programs is that you are using both sides of your body equally. The benefits of unilateral training and using both sides of the body equally are that it helps to avoid overtraining, overusing the dominant side, helps to isolate and correct muscle imbalances, improves balance, utilizes core muscles, aids in injury prevention, and facilitates rehabilitation.

When you train one side of the body the other side is stimulated and positively impacted. Indirect stimulation of the non-working side of the body via working the opposite side of the body improves strength in the opposite side (Green, et.al, 2018). This is called cross-education of muscles. Cross-education is a neural event. The brain pathways that are used for the primary unilateral exercise stimulate the same muscles on the opposite side of the body. The key to applying cross-education is to recognize that the phenomenon works for the same muscles on the opposite side of the body only. For example, doing a one-legged knee extension with the right leg will stimulate the left quadriceps muscle as well. Cross-education is greatest for lower body muscles and when eccentric (lengthening) contractions are used to train the working muscles (Manca et. al. 2017). However, concentric (shortening) contractions work also, as do isometric (no change in length) contractions to a much lesser degree.

To utilize unilateral training during sessions try the suggested exercises and routines below.

Low-impact unilateral lower body exercises include:

• Side Lunge
• Front/forward step lunge
• Back/backward step lunge
• One-legged or “pistol” squat
• Box step up

Upper body unilateral exercises include:

• One-armed dumbbell shoulder presses or lateral raises
• One-armed rows or chest presses
• One-armed standing dumbbell rows
• One-armed triceps extensions and biceps curls

To advance unilateral training try adding plyometric exercises. Plyometric exercises vary in difficulty and can be used to progress unilateral training routines. Note that the exercises below are ranked by level of difficulty from low to high. Start out with low-intensity exercises and add medium to high-intensity as indicated below later in a program.

Unilateral lower body plyometric drills include:

• Single leg push-off (low)
• Lateral push-off (low)
• Lateral box jump (medium)
• Jump split squat (medium)
• Single leg vertical jump (high)
• Single leg tuck jump (high)

To include unilateral exercises in workouts try these sample routines using any combination of the exercises above.

Unilateral Lower Body Superset

Alternate sides of the body – superset one exercise like a forward lunge and alternate right and left legs. The same thing can be done with arm exercises alternating right and left sides of the body.

Note: rest periods should reflect the volume (repetitions) and intensity of exercise and be longer if the volume and/or intensity is high.

Combined Lower Body Unilateral and Bilateral Superset

Choose a unilateral exercise like a box step up and alternate it with a set of squats (bilateral exercise) in between the two sets of unilateral exercises. Note that bodyweight only is suggested for the box step up; however, external resistance like handheld dumbbells can be added for intermediate to advanced clients.

Combined Upper Body Exercise and Plyometric Drill Circuit

For advanced programming and workouts, combine unilateral low-impact lower or upper body exercises with unilateral plyometric exercises. Repeat the circuit two to three times. Note that the suggested rest period includes zero – this is applicable where moving directly from one exercise to another is compatible with the client’s fitness level.

Unilateral training is an effective and fun way to add variety to workouts while focusing on more serious issues like muscle imbalances and post-rehabilitation training.

For more training tips, check out Timing Resistance Training.

Reference

Green LA, Gabriel DA. The cross education of strength and skill following unilateral strength training in the upper and lower limbs. .Journal of Neurophysiology. 2018;120(2):468-479.

Manca A, Dragone D, Dvir Z, Deriu F. 2017. Cross-education of muscular strength following unilateral resistance training: a meta-analysis. European Journal of Applied Physiology. November. Volume 117 (11); 2335-2354.