ATG SPLIT SQUAT: THE DEEP RANGE SINGLE-LEG EXERCISE THAT BUILDS BULLETPROOF KNEES AND ELITE LEG STRENGTH

What the ATG Split Squat Is and Why It Is Different

ATG stands for ass to grass, referring to a full range of motion squat that goes as deep as anatomically possible. The ATG split squat applies this full-range philosophy to the split squat pattern, requiring the front knee to travel forward over and past the toes in a deep lunge that reaches the absolute end range of knee flexion. This contradicts everything most gym coaches have taught about knee position, and the contradiction is intentional. The ATG method, developed by strength coach Ben Patrick, is built on the premise that training through full range of motion, specifically loading the knee in deep flexion, builds stronger tendons, healthier cartilage, and more robust knee joint function than the partial-range squatting that conventional strength programs prioritize. Research published in the Journal of Strength and Conditioning Research confirmed that deep range of motion squatting produces superior quadriceps development and knee extensor strength compared to partial-range alternatives. Quality knee sleeves keep the joint warm and supported through ATG split squat sessions.

The ATG split squat is not appropriate for every athlete at every stage of training. It requires progressive adaptation of the patellar and quadriceps tendons to the loading demands of deep knee flexion. Athletes who rush into full-depth ATG squats without progressive preparation risk tendon irritation. Athletes who progress slowly and systematically, starting with a slight elevation under the front heel and gradually increasing the depth and load over weeks, build the tendon resilience that makes the full ATG split squat one of the most productive knee health and leg strength exercises available.

The Muscle Groups ATG Split Squats Train

Quadriceps in Full Lengthened Range

The quadriceps are the primary movers in any squat pattern, but the ATG depth specifically loads the quad in its fully lengthened position, which produces a stretch reflex and eccentric stimulus that partial-range squatting cannot replicate. This full-range loading is particularly effective for developing the vastus medialis oblique, the teardrop-shaped inner quad muscle that stabilizes the kneecap and contributes to knee joint health. Athletes who develop VMO strength through deep range quad training consistently report improved knee stability and reduced patellar tracking discomfort.

Hip Flexors of the Rear Leg

The rear leg in the ATG split squat position stretches the hip flexors under load as the knee descends toward the floor. This loaded hip flexor stretch is one of the most effective treatments for the chronic hip flexor tightness that accumulates from heavy squatting, prolonged sitting, and limited hip mobility work. Athletes who perform ATG split squats regularly typically show measurable improvements in hip flexor length within four to six weeks that carry over into better anterior pelvic tilt, increased squat depth, and improved hip extension at the top of deadlifts.

Calves and Ankle Mobility

The forward knee travel over the toe in the ATG split squat requires and simultaneously develops ankle dorsiflexion range of motion. The calf muscles and Achilles tendon are eccentrically loaded as the knee travels forward, which builds lower leg resilience that reduces calf strain and Achilles tendinopathy risk in running and jumping athletes. For athletes with limited ankle mobility that restricts squat depth, the ATG split squat serves as both a training exercise and a mobility development tool simultaneously.

How to Progress Into the ATG Split Squat Safely

Stage 1: Elevated Heel Split Squat

Place the front foot on a wedge or elevated surface, 2 to 3 inches, to reduce the ankle dorsiflexion demand. Perform split squats through the deepest range available without discomfort. The elevation compensates for limited ankle mobility and allows deeper knee travel immediately. Begin with bodyweight for 3 sets of 10 reps per side. This stage builds the initial quad and knee tendon adaptation needed before progressing to flat-surface full ATG depth. Add knee sleeves from the first session to keep the joint warm through the new range of motion demands.

Stage 2: Flat Surface Deep Split Squat

As ankle mobility improves through consistent elevated heel training, gradually reduce the heel elevation until the exercise is performed on a flat surface. Focus on achieving depth where the front thigh goes below parallel and the rear knee approaches the floor. At this stage, begin adding light dumbbell load, 10 to 20 pounds per hand, to increase the strength stimulus while the range of motion and technique are being developed.

Stage 3: Loaded ATG Split Squat

With flat-surface full depth established, progressively increase the load through dumbbells, then a barbell in the front rack or back squat position. The ATG split squat at meaningful loads, 30 to 50 percent of bodyweight per hand in dumbbells, is a genuinely challenging strength exercise that produces elite-level single-leg quad and posterior chain development. Pair heavy ATG split squats with hip circle band warm-up work to activate the glute medius before each session.

Programming ATG Split Squats

For athletes new to ATG training, two sessions per week of elevated heel split squats is the appropriate starting frequency. The knee tendons adapt more slowly than muscles, and pushing frequency beyond two sessions per week before adaptation is established often produces anterior knee soreness that requires rest. Progress depth and load across four-week blocks, reassessing range and comfort before each progression. Athletes who have established full ATG depth at bodyweight can progress to three sessions per week with added loading.

Experienced athletes can use ATG split squats as a primary single-leg strength exercise alongside barbell squats and deadlifts. Three sets of 6 to 10 reps per side, performed with progressive loading across training blocks, builds the quad and hip flexor strength and the knee tendon resilience that makes every bilateral lower body exercise safer and more powerful. Supplement with cable ankle strap exercises for additional single-leg hip and glute development that complements the quad and knee focus of the ATG split squat.

ATG Split Squats and Knee Health: What the Evidence Shows

The conventional wisdom that the knee should never travel past the toe during squatting movements was based on a 1978 study that measured compressive knee forces in isolation without accounting for the full loading environment of a real squat. Subsequent research has repeatedly demonstrated that allowing the knee to travel forward naturally during deep squats is not only safe but produces superior quad development and knee tendon strength compared to artificially restricting the range. Research published in the Journal of Strength and Conditioning Research found that unrestricted knee travel during squats produced greater overall knee joint loading but no injury-related pathology when progression was appropriate, while restricted knee travel increased hip and lower back compressive forces significantly. The ATG split squat applies these findings by training the knee through its full functional range, building the tendon and tissue resilience that actually protects the joint under athletic loading conditions.

The key is appropriate progression. Jumping from no deep knee flexion training directly to full ATG depth under significant load is what produces tendon irritation, not the deep range itself. The staged progression approach in this guide, starting with heel elevation, moving to flat surface, then adding load progressively, gives the patellar tendon and quadriceps tendon the adaptation time they need to handle the novel stimulus of deep knee flexion loading safely. Athletes who have used this progression consistently report not only the absence of knee problems but actual resolution of chronic anterior knee pain that limited their training before ATG work began. Protect the knee throughout the progression with quality knee sleeves that maintain joint warmth and provide proprioceptive feedback through every deep rep.

Combining ATG Split Squats With Your Existing Program

ATG split squats integrate most effectively as an accessory movement following primary bilateral barbell work. After your heavy barbell squats or deadlifts, perform two to three sets of ATG split squats at whatever progression stage is currently appropriate. This sequencing uses the warm-up from the barbell work to maximize depth in the ATG sets while not competing with the primary movement for neural freshness. As ATG split squats become stronger and more fluid, they can be elevated to a primary movement with bilateral squats moving to a secondary accessory role. Many athletes find this rotation prevents the bilateral squat-specific fatigue that accumulates from always squatting heavy while introducing enough variation to maintain long-term training motivation. Add hip circle band activation before every lower body session and cable ankle strap exercises as additional single-leg accessory work to build the complete lower body development that ATG split squats support but do not cover entirely.

FINAL WORDS

The ATG split squat is a precision tool for building knee health and single-leg leg strength through the full range of motion that conventional training consistently avoids. Progressed carefully and consistently, it develops quad and tendon strength that directly reduces knee injury risk and improves bilateral squat performance. Start with heel elevation, progress depth and load systematically over months, and protect the joint through every session with quality knee sleeves. Build knees that last as long as your training ambitions do.