Yes you CAN, and yes you SHOULD. When we talk about a healthy lifestyle, daily movement needs to be part of it. Remember, the goal is fat loss, not muscle loss. Without any exercise, it is surely possible to lose weight with a ketogenic way of eating, however, some of that loss could be muscle density. Incorporating exercise into any nutrition plan will yield better, faster results. When the body is fat-fueled, you will notice an increase in energy and endurance, allowing you to power through your workouts and hold onto strong, lean muscle.