The False Binary: Why the Bilateral vs. Unilateral Debate Misses the Point
In the world of high-performance sport, coaches often find themselves trapped in binary thinking. We ask questions like: "Should I prioritize unilateral training or bilateral?" But this framing reveals a more fundamental issue in our field — a craving for the “right” answer instead of the optimal approach. Let’s be clear: it’s not about which is better, it’s about how to blend both with precision and intent.
Let’s start here — if you’re stepping on a grain of sand and it hurts, the problem isn’t the sand. It’s that you’ve lost perspective. You’re standing on the beach of opportunity and complaining about friction. That same friction can either sharpen your edge or weaken your frame, depending on your mindset and your model.
The False Choice
The debate around bilateral (two-legged) vs. unilateral (single-leg) training has become the chicken wings argument of strength and conditioning. Some prefer “drums” (rear-foot elevated split squats), others love “flats” (bilateral squats), and there’s value in both. But we’re not here to debate flavor. We’re here to optimize outcomes.
Saying unilateral training is "better" than bilateral is like saying a screwdriver is better than a hammer. It depends what you're building. If you're an athlete who needs to cut, jump, and land under chaotic conditions, you need both symmetry and force production. That means we’re using both tools — with purpose.
Biomechanical Reality: Force Wins
From a pure Newtonian physics standpoint, producing force is non-negotiable. And often, bilateral movements like back squats, belt squats, and leg presses allow for greater total force development due to the stability of the system. That doesn’t mean unilateral work is unimportant — it’s critical for addressing asymmetries, stabilizing the pelvis, and exposing weaknesses that bilateral lifts may mask. But they’re not interchangeable.
If you can Bulgarian split squat 250 lbs on each leg, that doesn’t equate to a 500-lb back squat. You're not doubling output. You're managing a different neurological and structural demand. The load may feel heavy on the leg, but the global system (spine, CNS, bracing, etc.) is experiencing a fundamentally different challenge.
You can’t Bulgarian your way through life. Sometimes you need the dump truck — not just the finely tuned Prius. A heavy bilateral lift trains the organism. It’s not about matching numbers on paper — it’s about respecting how the body organizes movement and force.
Neurology & Efficiency
From a neuroscience perspective, strength is a skill. It’s a motor pattern, not just a hypertrophic adaptation. When you train unilaterally, you're reinforcing contralateral spinal pathways. That’s great. But you also need to reinforce the pattern of bilateral integration, particularly in sports where explosive double-leg force production is a prerequisite for jumping, sprinting, or bracing.
This is where the CNS becomes the real player. The nervous system — not just your muscles — dictates output. The more pathways you can build, reinforce, and refine, the more adaptable you are. That’s why it’s dangerous to eliminate movement patterns from training. You’re not just dropping an exercise — you’re cutting off a lane on the neurological highway.
The Role of Safety: Misguided Fear
Let’s talk safety. The weight room is one of the most controlled environments an athlete will ever be in. Injury data consistently shows that Olympic weightlifting — when properly coached — has some of the lowest injury rates per hour of participation in all sports. You know what’s less safe? Decelerating a 200-lb opponent mid-play. Or landing awkwardly after a 40-inch vertical jump.
Avoiding bilateral lifts like squats due to fear of spinal compression or injury risk is an argument rooted in either poor coaching or poor preparation. Risk doesn’t come from the lift — it comes from load, frequency, poor mechanics, and inadequate support systems. Done correctly, bilateral strength work offers some of the best returns on investment in both performance and injury mitigation.
Load Transfer and Return on Investment
A strong bilateral base is the cornerstone for high-functioning single-leg performance. We’ve had athletes blow past perceived limitations in their single-leg outputs only to break down later with overuse injuries — adductor strains, patellar issues, SI joint flare-ups — all stemming from relying on single-leg loading as the driver rather than the accessory.
Let’s be clear: the sport will provide the single-leg stimulus. Your training needs to build a base that prepares the tissue for the real-world stress that’s coming. That means progressive bilateral loading to build general capacity — and strategic unilateral loading to target deficiencies and enhance stability.
Think of it in tiers:
Tier 1: Base bilateral strength (e.g., 1.5x bodyweight squat)
Tier 2: Speed under bilateral load
Tier 3: Controlled single-leg loading
Tier 4: Sport-specific dynamic loading
Trying to skip tiers or flip the hierarchy is how you create soft tissue problems, chronic compensations, and frustrated athletes.
Programming Perspective
From a programming standpoint, this isn’t about ideology — it’s about dosage. Exercise is a drug. The dose determines the outcome. Too much bilateral work with poor movement patterns? Breakdown. Too much unilateral work without a stable base? Breakdown. Precision matters.
Here’s a better question: “What dose of bilateral and unilateral training optimizes adaptation, resilience, and performance — without compromising movement quality?”
If you’re not asking that, you’re not programming — you’re just selecting exercises.
Real-World Example: Baseball and Volleyball
This year alone, we saw three non-contact injuries in baseball athletes directly tied to overreliance on heavy single-leg loading. Despite high outputs in training, these athletes lacked coordination and strength in bilateral patterns, especially under fatigue. Once they reintroduced bilateral loading and started respecting basic strength progressions, their pain vanished and their performance returned.
In sports like volleyball — where rapid acceleration, deceleration, and jumping are daily norms — the bilateral base becomes even more critical. Landing produces ground reaction forces 5–6x bodyweight. You better have a system that’s trained to handle that.
Bottom Line: Stop Looking for an Easy Answer
The goal isn’t to pick sides — it’s to build adaptable, robust, high-output athletes. That means respecting both bilateral and unilateral patterns. It means understanding tissue load, nervous system demand, movement coordination, and sport transfer. It means not fear-mongering athletes away from training hard under the guise of “safety” when the real issue is poor coaching.
Single-leg work is important. But it’s a tool — not the foundation. Bilateral loading is also a tool. They complement each other. One doesn’t replace the other.
So the next time you see someone debating unilateral vs. bilateral, remind them they’re standing on the beach — not in a sandbox. Stop fixating on the grain of sand in your toe. Look up. There’s an ocean of opportunity waiting.
