The kettlebell hack squat is regaining traction as a functional training tool for building knee resilience and targeting the vastus medialis oblique (VMO), according to fitness creator Adam Sinicki. By shifting the load behind the body and elevating the heels, this movement forces the knees to track forward, mimicking the mechanics of sprinting and explosive jumping while strengthening the lower body in vulnerable, real-world positions.
Why Functional Training is Moving Beyond Machines
Modern gym culture often prioritizes stability and ease of use through machines. However, Sinicki argues on his YouTube channel, The Bioneer, that this convenience can lead to the neglect of foundational movement patterns. The hack squat—traditionally performed with a barbell—is an example of a “forgotten” exercise that offers unique benefits for athletic longevity.
The movement’s name likely derives from the German word ‘hacke’, meaning heel, and was championed by strongman George Hackenschmidt. By performing this on the balls of your feet, you develop what Sinicki calls “ankle stiffness,” a critical component for energy return during running and landing.
Did you know?
The VMO, or “teardrop muscle,” is frequently cited by trainers as a key stabilizer for the patella. Strengthening this area through forward-knee movements may help reduce knee pain during high-impact activities like sprinting.
The Biomechanics of the Kettlebell Hack Squat
The primary advantage of the kettlebell variation is its accessibility for home training. Because the weight is held behind the glutes, the center of gravity shifts, requiring significant core engagement to maintain an upright, albeit slightly forward-leaning, torso.
How to Execute the Movement
- Hold a kettlebell behind your body using both hands, keeping your arms slightly apart so the bell rests against your glutes.
- Rise onto the balls of your feet.
- Lower yourself into a squat, allowing the knees to travel forward significantly.
- Drive back up while maintaining alignment between your toes and knees to prevent inward collapse.
Sinicki advises starting with bodyweight “Hindu squats” or using a support for balance if you are a beginner. Once the movement pattern is ingrained, he suggests that higher-rep sets—ranging from twenty to thirty repetitions—are highly effective for both muscle hypertrophy and strength endurance.
Future Trends in Longevity-Based Fitness
Industry shifts suggest a growing interest in “longevity training,” where the goal is not just aesthetic muscle gain, but the ability to perform daily tasks—like squatting to pick up objects or playing with children—without pain. The return of the hack squat fits into this trend of training for functional mobility.
Pro Tip:
Don’t rush the weight. This exercise is more taxing on the quadriceps than it appears. Start with a light kettlebell to master the balance required when squatting on your toes before attempting heavier loads.
Frequently Asked Questions
Is the hack squat safe for my knees?
According to Sinicki, the exercise is designed to build resilient knees by strengthening the muscles surrounding the joint in positions commonly used during sprinting and jumping. However, beginners should start with bodyweight variations to ensure proper form.
Can I build muscle with this exercise?
Yes. Sinicki notes that performing higher-rep sets (20-30 reps) provides sufficient stimulus for both building strength and increasing muscle size in the quadriceps.
Do I need specialized equipment?
No. One of the main advantages of this version is that it only requires a single kettlebell, making it an ideal movement for home workouts where space or access to large gym machines is limited.
Looking to optimize your performance? You can access a 4-week training plan created by coach Kori Sampson—designed to improve muscle-to-fat ratios and recovery—via the Men’s Health app. Have you tried incorporating the hack squat into your leg day routine? Share your results in the comments below.
Keep reading
