I have just done 470 mile in under 6 days for charity on a £100 mountain-bike that i have turned into a touring bike. I had 25-30kg's of weight that i took up the hills of Derbyshire (for my American cousins they are very very steep hills). Im 38 yrs old,i trained lightly,i smoke,drink and dont follow a balanced diet... Listen mate... If i can do that you are gonna be just fine.