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.