Nautilus Nitro Plus Leg Extension

The Nautilus Nitro Leg Extension delivers full knee extension quadriceps training with proper axis alignment throughout the movement, classic variable resistance cams for smooth consistent loading, quick-set leg pad, heavily padded movement arm roller, Ergo Grip® handles, partially shielded 245 lb weight stack with 5 lb increments, and 2"×4" steel frame — 557 lb commercial frame, 55"×36" footprint. The Nautilus Nitro Leg Extension is the commercial-grade counterpart to the Precor C-Line, S-Line, and Discovery leg extensions in the catalog — each built for the same quad isolation objective with different frame lineages and design details. The variable resistance cam is the engineering specification that distinguishes a biomechanically engineered leg extension from a fixed-resistance machine: a standard weight stack connected through a simple pulley applies the same force throughout the arc regardless of where the knee is in its extension range. The problem is that the quadriceps do not have uniform strength through the full knee extension range — they are strongest at approximately 60°–80° of knee flexion and weaker at full extension (0°) and at deep flexion approaching 90°+. A fixed resistance is either too heavy at the weak points of the arc or too light at the strong point. The variable resistance cam is shaped to vary the mechanical advantage of the lever system through the arc — increasing resistance where the quads are strongest and decreasing it where they are weakest — so the loading matches the muscle's actual force production capacity at each point in the range. The result is that the muscle works near its capacity through the entire arc rather than being limited by the weakest point. The quick-set leg pad allows rapid repositioning between users without tool-free adjustment delays — relevant in commercial environments with high user rotation. The 5 lb weight stack increments are finer than the standard 10 lb increments on many machines, allowing more precise load progression.

Ergo Grip® handles for stability throughout the extension arc. Traditional seat pads for familiar comfort. Partially shielded stack for clean aesthetics and accessible weight selection. 557 lb Nautilus Nitro commercial frame, 55"×36" footprint. Remanufactured.

Primary muscles targeted

Secondary muscles

Key features

Specifications