How Iridium Programs This

Iridium evaluates your sleep data and recent systemic load to ensure you have the recovery capacity for this high-fatigue conditioning movement. Since standard 1RM formulas do not apply to time-based exercises, the algorithm tracks progressive overload by monitoring your RPE trends relative to the sled weight. This volume is also credited toward your weekly limits for the lats and erectors to prevent interference with other back workouts.

Form Cues

Retract your shoulder blades and keep your chest proud.
Brace your core tightly to protect your lower back.
Drive through the balls of your feet with every step.
Maintain a slight forward lean from the ankles, not the hips.
Keep a consistent, powerful marching rhythm.

Don't

Don't let your shoulders round or hunch forward.
Don't hyperextend or arch your lower back.
Don't look down at your feet; gaze straight ahead.
Don't run or sprint unless specifically programmed.
Don't lose tension in the straps or harness.

Common Mistakes

Rounding the upper back
Leaning too far forward at the waist
Taking short, shuffling steps
Disengaging the core muscles
Starting with excessive weight

Muscles Worked

While the legs generate the forward momentum, this variation places a heavy isometric demand on the Latissimus Dorsi, Rhomboids, and Trapezius to maintain an upright posture against resistance. This engages the entire posterior chain, linking the power of the Glutes and Hamstrings through a rigid spine to the upper body.