My School Holiday plan

The school holidays, a time when you plan so much stuff to do. At the time of the thought there is such a huge sense of motivation, but for me, when it comes to actually doing it, i seem to loose all sense of motivation.
These holidays i'd planned to be really active, going bike riding, going on regular walks and getting back into wii fit. During last term at school I wasn't being very healthy and now have a small belly begining to grow. My aim was to go on a mini 2 week diety thing, at the time of thinking about it a few days before the holidays it seemed like a great idea.
well here I am, 1 week into the holidays and so far i have done nothing i'd planned to do, I find myself saying "I'll start tomorrow, i have things to do today" and that has been me for the past week. Well i've got just over 1 week to go before school goes back for another hectic term of Yr 12, lets see if I can find even a little motivation to do something other than sitting in front of the computer or TV.
Tim