For various reasons DS3 (14) was ill and off sport for a year. He was able to start doing PE at school again this academic year but he's a bit out of condition for his age. He wants to sort this out, so he's doing an hour a day jogging on the Wii fit, riding his bike around the place and going for walks (he doesn't like doing proper sports in public at the moment as he's quite self-conscious). He really wants to work at this over the summer holidays and be up to normal fitness by September. We would like to measure his fitness so he has a baseline to work from and motivate himself. Does anyone have any ideas about how we can do this at home with no specialist equipment? Are there any tables/charts/techniques we could use?