Just open up the pockets and you're fine.

 But less aero then.

 Yessir!!!

 My gf's bag holds two water bottles, two jackets, a sweater and some candies and stil a bit of space left. It's made of 1000d nylon PU coated on the back and with water repellent finish sewed with nylon thread - it's a very heavy duty bag.

 Thanx Niko : D