i'm nervous....

i am going on a trail ride sat. with 2 friends....and i'm nervous. it's a 13 mile ride, and i haven't ridden that far in.... years.... poor nike he's so fat. i'm just worried about him, but i mean, mist did it last year and she had even less riding beforehand than nike's gotten... *sigh* i know it'll be fun, but...i get nervous.