That depends on what type of fuel your body is used to. If you run predominantly on carbohydrates (glucose) as a source of fuel, consuming carbs can certainly help your body replenish empty glycogen stores.  However, if you’re fat-adapted and use fat (fatty acids or ketone bodies) as your primary source of fuel, there is no need to consume carbs to replenish your glycogen stores. In fact, studies have shown that elite athletes who are on a ketogenic diet replenish their glycogen stores at the same rate as athletes who run on carbs. The likely reason for that is the body’s ability to make glucose from non-carbohydrate sources via a process called gluconeogenesis.