The best of your workouts are right after the carb-up. The next day is usually a good idea to workout. Now, usually you'll stay in the same strength levels, but later in CKD, as you gain muscle, your strength will go up.
This is a trick I use to feel better during my workout:
(sounds very unrealistic, but has helped me a lot)
Before I workout, I eat 5-7 carbs. (ex: 2tbsp. all natural peanut butter) This seems to help not only mentally but even physically. I read a study a while back stating that even 5 carbs before a workout can improve performance.