I have been following a low carb, low fat diet for 4weeks. I am an advanced weight trainer. I do cardio 3-4 days a week and wt train 4 days a week. Initially on the diet I lost about 7 pounds. In 3 weeks time I have gained back all but 3 pounds despite serious hard work at the gym and following the diet. Everyone says "Oh it's muscle weight" My question is : How fast does a person gain this muscle weight? What is the average # pounds a woman can put on in 2 weeks time????