Before eating anything, drink at least a liter of water, wait 20 minutes, then eat. An ideal first meal after Maghrib is a small handful of dates. Your body needs good, clean nutrition during Ramadan even more than it does during the rest of the year. Don't stress your system out by eating a bunch of sweets and junk.
Ramadan should not be an excuse for you to stop exercising. In fact, you should continue your regular exercises and keep them between 30 â€“ 45 minutes with slightly lower intensity. The best time to workout is after the evening prayer before dinner or before suhoor.