TweetThis only my opinion, but you need way more than 20 grams of carbs a day if you want to get all you can out of the sust. This may also be why your feeling tired. Stick to whole grains (breads, pastas, and rice) and plain baked potatoes/sweet potatoes. Oatmeal is also very good for workout fuel. I try to get around 100 grams at least every day, with the majority in the earlier half of the day and then tapering down for the rest of the day. Limiting your carb intake while on AS is simply limiting your potential growth. Just my 2 cents.