Physical fitness comes in many forms - some pople spend their time in the gymn working with heavy weights to gain much larger msucles, and some spend their time in the gymn improving their timing and balance
Here is video of Danny MacAskill's bicycle riding done his way, of course, in a gymnasium - There are even some of he outtakes at the end of the film showing how much hard work goes into each of his videos.
I think almost anyone who enjoys riding bicycles may enjoy Danny's videos, because they will appreciate just how difficult his riding feats are - some even look scary dangerous.
He is a distant cousin of yours isn't he @Chris ??
And for those of you who enjoyed the video above, here is a link to many more of his videos - a great way to spend a rainy morning