Oblique Bend
A. Sit up straight and hold a filled 24 water bottle in your hand. Palms facing out and arms down your side. 

B. In one smooth motion, raise your arm to the side.

C. Raise your arm all the way overhead extended as far as comfortably possible. After working 30 seconds, switch arms. 

REPS: Do 60 seconds (30 + 30)
Works your shoulders

 A. Sit up straight on the edge of your seat. Place the 24 bottle between your knees.
Contract your inner thighs and slowly squeeze the 24 bootle as hard as you can. Hold the contraction for 5 to 10 seconds.
Relax slightly and squeeze again.

Works your shoulders

 A. Sit up straight on the edge of your seat. Grasp the 24 bottle on your right hand and place it on your right side arm bend.

 B. Extend your arm straight to your side.

   C, D, E. Without bending elbow, rotate your arm clockwise, using the 24 bottle to draw large imaginary rainbow above your body. 
Finnish the rainbow by returning to the starting position. 
Next repeat the same but this time in a counterclockwise direction.

That´s (1) one rep.
REPS: Do 30 secods with each hand
Works your shoulders