[VergeOfDiscovery]

I love the swimming pool idea, but sadly that`s a bit out of the question whilst i`m still Pre-Op. if I do get some of these weight thingies, then what do I do with them? and are you 100% sure that I won`t get muscle definition or other masculine like traits?

Just used mine.

Raise them over my head. 
Do sort of a slow punching motion out away from my chest.
Curls.
Other assorted motions.

The greater the concern regarding increased definition, the lighter the weights.

Perhaps stop by a Target or somewhere that has the different sizes to try out. Many places like TJ Max & Marshalls sometimes have some (for women and on the lighter side, and usually in bright colors).

Another option is fast walking with light wrist wrap hand weights geared for that activity. The latter is often even easier to find than dumbbells.