If you consistently miss the window of opportunity that exists after exercise to replace muscle glycogen stores, you set yourself up for poor training and racing efforts in the upcoming days. The physiology behind this phenomenon is simple. Because of this, the carbohydrates you consume on a daily basis influence the amount of muscle glycogen stored. That's an extra boost needed by those runners who train daily. In addition, training efforts are usually perceived as being easier when muscle glycogen is maintained throughout a workout.
Researchers continue to refine the formula for optimum muscle glycogen repletion.
A key element is the timing of your carbohydrate injections. A period exists after intense or long endurance exercise where muscles are most hungry for glycogen restoration. This window can quickly close, though, as you hunt for family members following a race, or stretch, or shower and redress before scurrying back to your desk. Furthermore, since exercise tends to elevate your body temperature, which in turn can depress your appetite, you can't rely on hunger cues to prompt proper refueling. Obviously, soft drinks aren't the ideal daily recovery fluid, as they lack nutritional value, but they'll do in a pinch.