Temple of Gainz The Quadrilogy Leg Extension Seated Leg Curl Machine

THE QUADRILOGY™ Leg Extension + Seated Leg Curl

THE QUADRILOGY is the fourth generation of our popular Leg Extension + Seated Leg Curl machine. It builds upon the feel, functionality, and adjustability of previous versions while incorporating higher felt resistance*, significant structural upgrades, premium materials, and numerous improvements developed from customer feedback.

The Quadrilogy is also one of the first selectorized Temple of Gainz machines available with our patent-pending Beyond Power VOLTRA Digital Resistance Integration. This optional configuration allows a compatible Beyond Power VOLTRA to replace the traditional weight stack, reducing the initial cost of the machine while providing greater control over resistance, eccentric loading, and resistance-curve customization^.

Estimated Shipping Timeline

Orders placed now are expected to ship by the end of November 2026.

Machines are currently on their way to us, with incoming inventory allocated to fulfill existing orders. Orders will ship in the order they were received.

All shipping dates are estimates and are subject to production, freight, and other delays. Please review our payment and cancellation policies, which apply to all purchased and unfulfilled orders.

What Is The Quadrilogy?

The Quadrilogy combines two highly effective lower-body isolation exercises, the leg extension and seated leg curl, into one heavy-duty machine with a compact footprint.

A fully adjustable back pad moves forward and backward to accommodate a wide range of users and body proportions. The extended seat pad and multiple back-pad positions provide additional support for taller users and those with longer legs.

The movement arm offers ten starting positions, while the leg roller includes five adjustment positions. The thigh pad provides ten secure starting positions for the seated leg curl. Together, these adjustments allow users to customize their starting position, range of motion, and alignment for both exercises.

Laser-engraved adjustment numbers on the movement arm, leg roller, and thigh pad make it easy to record and consistently repeat preferred settings.

The recessed front crossmember provides greater clearance and range of motion at the beginning of the leg extension and the end of the seated leg curl. The repositioned thigh pad and updated handle placement further improve comfort, stability, and ease of use.