Every September, the same thing happens in my coaching practice. The trail runs get rained out, the evening light shrinks, and one by one my clients start asking about the same machine — the one gathering dust in the corner of their gym while they wait in line for a treadmill. By October, half of them have a rowing machine in their living room, and every single one of them asks me why they waited so long. I felt the same way in college, when my heptathlon coach stuck me on an erg for the entire off-season to protect a…