Forty minutes on the treadmill gets the attention, but the twenty minutes on the floor afterwards decides more of your plan.
Single-leg calf raises to failure, a hop test for reactive stiffness, hip abduction under fatigue and an ankle range check. None of it is glamorous and all of it predicts more than a VO2 number does.
Anything over a five percent left-right split gets a strength prescription rather than a longer run. That single rule has removed more lost weeks from this club than any change to the session board.