as above
- do fun things to increase your base fitness without it feeling like formal training.
save your mojo for when you need it
but being fit at the start of the program is a lot better than being an unfit couch potatoe
so get yourself some fun sessions to do in the week, and weekend, These can include running / biking etc if thats what you enjoy, but its just fun stuff not 'training'
Do some gym classes, do some casual rides if the weather is good at the weekends,
mountain biking is great if thats your bag..... etc etc
So enter some MTB enduros, half marathons etc and have fun.