## Sweating f(x) dx

While running on a treadmill at
The Gym
the other day, I noticed that I was doing integrals in my head. The
T9i
treadmill
has a "random" workout program which keeps the speed constant but varies
the incline every ten seconds to turn a medium jog into an anaerobic
slog. The level of incline is shown simultaneously by a numerical
indicator of the console (percent?) and by a spiky vertical bar-graph
over on the left hand side. Naturally I wanted to associate the graph
with a profile of the simulated terrain I was running over, but unfortunately
the peaks show the points of greatest effort/greatest slope, not
the summits of the hills. It was clear that despite this unit's other
virtues, providing downhill inclines was not among them. Thus the need
for
integral calculus
(this being a lovely illustration from Newton's treatise

*Quadrata Curvarum*), which really isn't as hard as one might think, since the bar-graph is made of nicely stackable little boxes.It would have been nice if they had an indicator
of how many feet I'd climbed since the beginning of the workout, similar
to the display on the stair climber machines which told me how many
floors the person exercising would have ascended.