How can I improve my fitness in 11 days?

LOTS of cardio, stretching, agility exercises and some weight training. Running, swimming, jumping rope, things like that. Exercise A LOT, just be very very very sure that you drink at least 10 glasses of water a day and eat plenty of carbs and protein.

First off, don't plan to just ''improve your fitness in 11 days.'' Plan to improve it for life by making your new fitness activities a habit. Anyway, make sure that you stretch out before and after your workouts. You should also do this when you get out of bed or up from laying down/sitting for a long time. Throw an extra set of push ups, sit ups, and jumping jacks (or jump rope) in throughout the day a couple of times. Just do what you normally do to keep tone and in shape, but pick it up a bit. Run a few additional minutes in the morning and then later in the day. You konw what to do - just do it!!

You would have to do like a bootcamp thing. Really hard workouts...

But then again just doing a regular wourkout will give you benefits.

Drink more water....Cus staying hydrated is cool!

continue to work out extra but just remember it takes appromately 21 days to form a habbit of working out

yes you can