Upper Legs Exercise · Barbell
Biomechanical cues verified by the PlanWorkouts Science Review Board under CSCS editorial oversight; see our editorial standards.
The Barbell Hack Squat is a compound upper legs movement designed to train the Glutes with direct engagement of the Hamstrings, Calves.
Operates primarily in the sagittal plane involving knee flexion/extension and hip extension. Peak mechanical tension occurs in the deep lengthened position at the bottom transition. Maintain midfoot balance and an upright torso angle. Executing this with strict form maximizes muscle fiber recruitment while protecting joint structures.
Quick Exercise Facts
Target Muscle Activation
The barbell hack squat, done with the bar behind the legs rather than on the back, is the original version of the exercise before hack squat machines existed. It shifts the balance point and demands more from the quads and grip than a standard back squat. It's rarely programmed today outside of old-school strength circles, mostly replaced by the machine version for practicality.
How to Do the Barbell Hack Squat
- Begin standing with your feet shoulder-width apart and toes turned out slightly.
- Hold the barbell behind your legs, letting it rest against your upper thighs.
- Bend at the knees and hips to lower your body, keeping your back straight and chest lifted.
- Keep lowering until your thighs are parallel with the floor, or as far as you can comfortably manage.
- Pause briefly, then drive through your heels to return to the starting position.
- Perform for your targeted rep count, focusing on a deliberate tempo and maximum tension in the glutes.
Recommended Sets & Reps by Training Goal
70–80% 1RM · 90–120s rest
85%+ 1RM · 2–3 min rest (Calc 1RM)
50–60% 1RM · 45–60s rest
Biomechanical & Joint Load Cues
Operates primarily in the sagittal plane involving knee flexion/extension and hip extension. Peak mechanical tension occurs in the deep lengthened position at the bottom transition. Maintain midfoot balance and an upright torso angle.
Common Mechanical Mistakes & Form Errors to Avoid
- Knee Valgus (Inward Collapse): Allowing knees to cave inward during the ascent places excessive tensile stress on the MCL and lateral meniscus. Drive knees out in line with second toes.
- Excessive Forward Pitch: Allowing the chest to drop and hips to shoot up turns the squat into a good-morning, transferring load off the quadriceps onto the lumbar erectors.
- Heel Lift & Weight Shift: Shifting balance forward onto the balls of the feet compromises stability and increases patellar tendon strain. Keep weight distributed over midfoot.
Proper Breathing Patterns & Core Engagement
Perform a deep abdominal brace (Valsalva maneuver) into the diaphragm before initiating descent. Hold intra-abdominal pressure through the bottom transition, exhaling past the sticking point on ascent.
Add the Barbell Hack Squat to Your Custom Workout Routine
Build a personalized, science-backed workout plan matching your training goals, equipment access, and schedule.
Injury Modification & Joint Safety
Lifters experiencing acute patellofemoral knee discomfort should moderate depth to parallel or utilize box squats to reduce peak anterior patellar shear. If joint irritation persists, immediately stop and substitute this movement with another exercise from the Upper Legs exercises category.
Muscles Worked
The Barbell Hack Squat primarily targets the Glutes, with Quadriceps as the primary synergist muscle group, along with the Hamstrings, Calves.
More Upper Legs Exercises
All Fours Squad Stretch
Arms Apart Circular Toe Touch (male)
Assisted Lying Glutes Stretch
Assisted Lying Gluteus And Piriformis Stretch
Assisted Prone Hamstring
Assisted Prone Lying Quads Stretch
More Glutes Exercises
Band Bent-Over Hip Extension
Band Hip Lift
Band Lying Hip Internal Rotation
Band Pull Through
Band Seated Hip Internal Rotation
Band Squat
Equipment Alternatives
Don't have barbell? These target the same glutes with different equipment.
FAQ
- What muscles does the Barbell Hack Squat work?
- The Barbell Hack Squat primarily targets the glutes as the primary agonist. Synergist assistance is provided by the quadriceps along with the hamstrings, calves. Maintaining strict biomechanical alignment ensures maximal tension remains focused on the intended muscle fibers rather than shifting to surrounding stabilizer joints.
- What equipment do I need for the Barbell Hack Squat?
- The Barbell Hack Squat is performed using a barbell. Ensure all equipment is securely positioned with collars or safety pins locked before loading working sets. If you train in a home gym or minimal setup, explore our equipment-free and resistance band alternatives below.
- What is the most common form mistake on the Barbell Hack Squat?
- The most frequent error is knee valgus (inward collapse): Allowing knees to cave inward during the ascent places excessive tensile stress on the MCL and lateral meniscus. Drive knees out in line with second toes.. Controlling the 2 to 3-second eccentric lowering phase ensures maximal hypertrophic stimulus while shielding connective tissue.
- How many sets and reps should I perform on the Barbell Hack Squat?
- For muscle hypertrophy and size, aim for 3 to 4 working sets of 8 to 12 repetitions at 70% to 80% of your 1RM with 90 to 120 seconds rest. For absolute strength development, prioritize 4 to 5 sets of 3 to 6 heavier reps with 2 to 3 minutes rest.
- What's a good alternative to the Barbell Hack Squat?
- If you don't have access to a barbell, the Basic Toe Touch (male) targets the same glutes using body weight instead. This alternative replicates the same joint angle and movement plane while allowing you to train effectively with different available gear. You can also substitute it seamlessly in our free Workout Plan Builder.