Bicycles are really healthy, cost little to acquire, are easy to repair, last for ages, and work reasonably well in most climates.

the bicycle is one of the most efficient forms of transport... half the energy per unit distance of walking ... converts to about [there are 2 claims in wikipedia, 732 and 879 mpg]

I strongly suggest any hackers (aging and pot-bellied or otherwise) give long distance cycling a go: it's truly pleasurable and great for your brain! I spend much of my 20s doing this in foreign countries.