So about 3 weeks ago I decided to start a rigorous exercise routine. I went from basically not working out at all to working out 4-6 times a week. In my workouts I normally do about 20-30 minutes of cardio, strength training on abs and arms. Well, I was fine for about the first 2 weeks and now I am just exhausted!! After I workout I can barely hold myself up. Why is this happening? Is this my body's way of losing weight? Is there anything I can do to get my energy back and still lose weight? My roommate told me I need to eat more but that would defeat the purpose of exercising to lose weight/tone up.