Call your doctor, it is not my place to be giving you my advice here since some doctors have different feeling about exercise and they may have different advice for different patients depending on multiple factors. Usually there is no problem with walking and stationary biking and reasonable weight lifiting but be careful of repetitive face down exercises and very vigorous exercise. If you notice any specific noticable changes in the floaters in a worse way, or new flashes,or vision loss then call your doctor. For specific exercises you will have you ask your doc as well.