Unilateral Training for Muscle Growth: The Science & Benefits
When it comes to building strength and muscle, most people picture loading up a barbell with heavy weights and performing big, compound lifts like squats, bench presses, and deadlifts. These classic bilateral exercises certainly have their place, and they’re highly effective for developing overall power and muscle mass. However, there’s a powerful tool you might be overlooking that can take your training—and your results—to the next level: unilateral training.
Unilateral training involves working one side of your body at a time, and while it may seem less intense compared to heavy barbell lifts, it offers unique benefits that can greatly enhance your strength and muscle-building efforts. By isolating one limb, you not only address strength imbalances that develop over time, but you also challenge your core stability, coordination, and muscle recruitment in ways that bilateral exercises can’t. This kind of training forces your muscles to work independently, ensuring both sides of your body are equally strong and developed.
Beyond balance and stability, unilateral movements can help reduce your risk of injury. When you focus on one side at a time, you can more easily identify and correct weaknesses or imbalances, which might otherwise go unnoticed during bilateral exercises. This greater awareness and control lead to a more structurally sound and resilient body. So, while traditional lifts remain staples, incorporating unilateral training into your routine could be the missing piece that helps you build well-rounded, functional, and impressive muscle.
What Unilateral Training Does to Your Body
1. Enhanced Muscle Activation
Unilateral exercises engage stabilizer muscles that bilateral exercises often overlook. When you work one side of your body at a time—like performing a single-leg squat—your central nervous system recruits additional muscles to keep you balanced. This results in higher activation of the working muscles, even when using lighter weights. For example, single-leg movements can trigger greater activation in muscles such as the gluteus medius and hip stabilizers compared to exercises where both legs work simultaneously.
2. Balanced Strength and Muscle Development
Training each limb independently helps address and correct strength imbalances that can develop from daily habits, like favoring one side of your body. Over time, these imbalances can hinder performance and increase your risk of injury. Unilateral training allows you to strengthen each side equally, promoting more symmetrical muscle growth. This balance not only improves aesthetics but also ensures that both sides of your body can share the load evenly during everyday movements or sports activities, reducing strain and enhancing overall strength.
3. Core Stability and Coordination
Unilateral movements place a heavy demand on your core muscles. Because your body must stabilize itself when only one side is working, your core engages to prevent you from tipping over or twisting out of position. This extra stabilization effort builds a stronger core and enhances your body’s overall coordination. Exercises like single-leg deadlifts require significant core activation, which translates to improved posture, better balance, and more efficient movement patterns both in the gym and in daily life.
The Science Behind Unilateral and Bilateral Deficit
The concept of the bilateral deficit is rooted in how our nervous system controls muscle force production. The bilateral deficit refers to a phenomenon where the total force produced by both limbs working simultaneously is less than the sum of the forces produced when each limb works individually. Essentially, if you were to measure the maximum force output of each leg during a single-leg press and then compare it to the force generated by both legs pressing together, the combined effort would be slightly lower than expected. This is due to the way our central nervous system coordinates muscle activation during bilateral movements.
When performing bilateral exercises, like barbell squats or deadlifts, your brain sends signals to multiple muscle groups at once. The neural pathways responsible for recruiting these muscles may not fully activate every available muscle fiber in both limbs simultaneously, leading to a slight reduction in overall force output. This neural efficiency trade-off can be beneficial for some exercises but may limit the potential for maximum force production compared to unilateral movements, where the brain can focus more specifically on one limb.
Unilateral training combats the bilateral deficit by isolating each side of the body and training it to develop maximum force output independently. This has a significant impact on muscle and strength development. For instance, when you perform a single-arm dumbbell press, your central nervous system is solely focused on activating and coordinating the muscles in that one arm, which often leads to greater muscle fiber recruitment and increased force production compared to when both arms work simultaneously.
Moreover, the added benefit of unilateral training lies in how it enhances motor unit recruitment. Motor units, which consist of a motor neuron and the muscle fibers it controls, are activated more efficiently when focusing on a single side. This can lead to improvements in muscle strength and endurance as each side learns to operate at its full potential without the neural limitations of bilateral coordination.
Another interesting effect of unilateral training is its impact on cross-education. Research has shown that training one limb can result in strength gains in the untrained limb, a phenomenon known as the cross-education effect. This occurs because the neural adaptations from training one side of the body are partially transferred to the other side through shared neural pathways. This makes unilateral training a powerful tool for overall strength development, even when dealing with injuries or needing to prioritize one side over the other.
Here’s a well-rounded, three-day plan focusing on unilateral exercises for optimal muscle building. You’ll work your entire body while emphasizing both strength and stabilization.
Day 1: Upper Body Focus
Single-Arm Dumbbell Bench Press
3 sets of 8-12 reps per side
Focus on keeping your core engaged to avoid rotation.Single-Arm Dumbbell Row
3 sets of 10-12 reps per side
Ensure a full range of motion, pulling your elbow past your torso.Single-Arm Shoulder Press
3 sets of 8-10 reps per side
Keep your body upright and avoid leaning to one side.Single-Arm Bicep Curl
3 sets of 10-12 reps per side
Use a slow, controlled tempo.Single-Arm Overhead Tricep Extension
3 sets of 10-12 reps per side
Keep your elbow close to your head.
Day 2: Lower Body Focus
Bulgarian Split Squat
3 sets of 10-12 reps per side
Elevate your rear foot on a bench and drop your back knee straight down.Single-Leg Romanian Deadlift
3 sets of 8-10 reps per side
Keep your core braced and maintain balance through your entire foot.Single-Leg Leg Press
3 sets of 8-12 reps per side
Adjust the weight so you have full control throughout the movement.Single-Leg Calf Raise
3 sets of 12-15 reps per side
Pause at the top to engage your calves fully.
Day 3: Full Body and Core Stability
Single-Arm Kettlebell Swing
3 sets of 12-15 reps per side
Focus on the hip hinge movement and stabilize your core.Single-Arm Farmers Walk
3 sets of 30 seconds per side
Grip a heavy dumbbell and walk in a straight line, keeping your core tight.Single-Leg Glute Bridge
3 sets of 10-12 reps per side
Drive through your heel and squeeze your glutes at the top.Side Plank with Leg Lift
3 sets of 8-10 reps per side
Engage your entire side body and lift your top leg for added difficulty.Single-Arm Landmine Press
3 sets of 10 reps per side
Anchor a barbell in a landmine attachment and press up at an angle.
Unilateral training is more than just a corrective tool; it’s a muscle-building powerhouse. By focusing on one side at a time, you’ll recruit stabilizing muscles, fix imbalances, and develop more even and functional strength. Add these moves to your routine, and you’ll see the difference in your power and physique!
Hope that helps!
Happy Exercising,
Robyn