Christine- You may not be doing anything wrong per se. When beginning to low carb, a lot of us feel this weakness. As your body gets used to it, and especially when you slowly up the carbs, it gets a lot better.

Also, the supplements I can't recommend enough are calcium, magnesium, and potassium. LC is a natural diuretic, so even while drinking ample water, your body will be depleted of electrolytes at the beginning. Taking these supplements usually relieves weakness and leg aches that you might be experiencing. I know they help me.

Hope you start to feel better. I promise you that your energy will come back!