I just started working out with a trainer again. It's been two weeks. I may have gained some muscle, but come on! I know I've been feeling bloated and that may be part of it and then I just ran out of my meds which keep me from retaining fluid, but really, 5 pounds? I haven't been eating perfect, but not THAT bad! I was like 105 pounds so 5 is a big difference for me. I'm really annoyed. How much more does muscle weigh than fat? I work out with a trainer who trains you very intensely but for only once a week, and then you let your muscles rest. So I've been twice. I've also been stressed. Can that make you retain fluid?