The last lower body day of the program puts two lunge variations back to back with no rest between them. Four 15-second intervals - lunge step-ups on the right, split lunges on the right, lunge step-ups on the left, split lunges on the left - three, five or seven sets, one minute of rest.
This is thirty unbroken seconds per leg, and both exercises load the same front thigh. The step-up is the explosive one, driving up to a knee lift and dropping back down; the split lunge that follows removes the travel and the rise entirely, keeping the feet planted and grinding straight up and down in the stance. Dynamic then static-footed, both on the same side, and the second interval arrives on a leg that has already been driving for fifteen seconds. It is the hardest lower body session in the program and it is placed exactly where you can handle it.
Stay tall in both and keep the front shin close to vertical. On the step-ups, full knee drive and controlled descent. On the split lunges, drop straight down and push straight up - and when the thigh starts burning around second ten, shorten the range rather than breaking the tempo.
Day 2 gave each leg two exercises with a break between them; Day 58 gives it two with none.
Make it Harder: Pause for a full second at the bottom of every split lunge before driving back up.
Make it Easier: Cut the depth on the split lunges and let the step-ups finish at standing without the knee drive.
