The unilateral versus bilateral training debate is just about as controversial as what came first, the chicken or the egg? If you were to ask personal trainers, fitness coaches or performance specialists which one’s better, you would get a mix of responses. To make things easier for you, I am going to break down the differences between unilateral and bilateral lower-body training. The best one for you depends on where you are on your fitness journey or performance goals.

Unilateral Training

Unilateral training involves asymmetrical exercises that only use one side of your body at a time. A unilateral lower body movement involves the use of one leg. There are varying intensities when it comes to unilateral lower body training depending on whether the exercises are done with free weights or machines. Here are examples of unilateral lower-body exercises (with accompanying video):

• Split Squat
• Piston Squat
• Lunge Variations
• Single-Leg Romanian Deadlift
• Single-Leg Glute Bridge
• Single-Leg Hip Thrust
• Step-Up
• Step Down
• Single Leg Stability Ball Hamstring Curl
• Single-Leg Press
• Single-Leg Extension
• Single-Leg Hamstring Curl

Bilateral Training

Bilateral lower-body training involves the use of both legs symmetrically. Bilateral lower-body exercises are the staples of most strength programs. Here are examples of bilateral lower-body exercises (with accompanying video):

• Squat Variations (Back Squat, Front Squat, Overhead Squat)
• Deadlift
• Romanian Deadlift
• Trap Bar Deadlift
• Clean Variations
• Snatch Variations
• Leg Press
• Leg Extension
• Glute Bridge
• Hip Thrust
• Stability Ball Hamstring Curl
• Glute Ham Extension
• Nordic Leg Curl

Benefits of Unilateral Training

Unilateral lower-body training is great for improving muscle imbalance, kinesthetic awareness and stability. The asymmetrical nature of these exercises cause your body to stabilize joints and core muscles to maintain balance while executing the movement. If you have had an injury or dysfunction in your lower extremities, unilateral training will help isolate those weak points, and the appropriate exercise can help strengthen to restore full health and function.

Unilateral training puts more isolated stress on the single limb being worked. This allows people to put stress on their limbs without overloading with weight, which can increase risk for injury. Unilateral training also translates to sport more because movements like sprinting, cutting and jumping are all done on one leg or in a staggered unilateral position. For your training to translate, specificity in your strength training is key for the best results.

Benefits of Bilateral Training

There are many benefits of bilateral lower-body training. These include greater muscle recruitment, strength gains, central nervous system adaptation, hormone response, greater metabolic effect, and it requires less coordination.

When performing bilateral lower-body exercises, balance and stability are less of a factor compared to unilateral training. This gives you the ability to lift more weight. If your goal is to increase strength, muscle mass, power or speed, bilateral training will help you make the necessary gains to reach your goal.

There may be some specific transfer to sports for some athletes, but for the most part bilateral training is more beneficial in the offseason when the focus is on building a foundation of strength. When getting closer to pre-competition or competition phase you will want to focus on more specific movements that mimic your sport.

How to Implement Unilateral and Bilateral Training into your Workouts

Both bilateral and unilateral lower-body training exercises are beneficial whether you are looking to improve your fitness or performance for sports. The most important thing to consider when selecting bilateral or unilateral lower-body exercises is what is your No. 1 goal? Do you want to maximize your strength? Do you want to improve your balance, core strength or stability? Are you recovering from an injury and looking to strengthen an isolated joint or muscle group? Answering these questions before making exercise selections will help you map a plan of action before putting together an exercise routine.

My recommendation is to combine both bilateral and unilateral training in the same session. After completing a thorough warm-up, start with a compound bilateral exercise such as a Squat or Deadlift. It is important to do these exercises while mentally and physically fresh because they are more taxing than unilateral exercises. After completing one or two compound bilateral exercises, add in one or two unilateral exercises. Another option to consider is switching back and forth between hip dominant exercises (Deadlift, Hip Thrust, etc.) and knee dominant exercises (Squats, Step-Ups, etc.).

Below is an example of a combined bilateral and unilateral lower-body training routine.

Example 1

Bilateral

• Back Squat 3×8-12

Unilateral

• Single-Leg Romanian Deadlift 3×8-12
• Unilateral
• Dumbbell Lunge 3×8-12
• Bilateral
• Stability Ball Hamstring Curl 3×8-12

Example 2

Bilateral

• Deadlift 4×5
• Unilateral
• Bulgarian Split Squat 3×6
• Bilateral
• Nordic Leg Curl 3×8

Unilateral

• Single-Leg Hip Thrust 3×8

Photo Credit: shapecharge/iStock, Photology1971/iStock

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