My sister is attending an exercise class and has been remarking rather often about it taking her over 15 minutes to run a mile on the treadmill, and then boasted quite vocally when she managed to make it under 15 minutes. Her time on incline, though, is over 18 minutes for a mile.
Well, I decided I'd try to give her a run for her money. Eh. Half a mile and ten minutes on an incline before I felt like I was going to collapse, and that's just what I did for the next half an hour or so. I then slept for the next hour or two and finally felt like I wasn't about to faint.
My brother termed it quite appropriately. You (meaning me) can't just take up exercise after two years and expect to win the Olympics. Yet that has always been my philosophy.