Exxentric builds novel athletic training devices using flywheels for safe, eccentric overload and high rate of force movements. Traditional static loads with barbells and bumper plates are replaced by capturing the user's concentric energy and applying it as resistance. The kBox series allows single-leg and bilateral squat, deadlift, and rowing variations by simply changing attachments. The kPulley unlocks horizontal pulling, rotation, and lateral movement - ideal for martial arts and many sports. Obtain performance data with the kMeter: a digital display of power, energy, and force measurements. Numerous studies back the efficacy of eccentric and rotational training for athletic performance and injury resilience. Use smaller, low-inertia flywheels for power training and larger, high-inertia discs for strength development; easily swap and combine multiple flywheels to satisfy any application in the home gym, club, or competition environment. Lightweight, portable options are available for the kBox and kPulley for travel and outdoor workouts.