Physical Activity
One hours running training with a 70% VO2max intensity (which represents about 16 on the so-called Borg-scale and around a 160 pulse rate for a 20 year old i.e. intensive training), burns about 1000kcal in a man who weighs 80-85kg. At such an intense level of training around 80% of energy comes from carbohydrates. This means to say that with such intensive training around 200 grams of carbohydrates are used up. This increases the need for carbohydrates, which as a result means that carbohydrate stock levels become depleted and need to be replenished so the body has a chance to recover before the next activity.
The carbohydrate reserves are stored as glycogen in the muscles and liver. Total reserves can reach about 300-500 grams in a "normal" person and up to 1kg for an elite athlete at maximum stock levels. Especially important is the replenishment of depleted stock levels after an intense work out, when training daily or even several times a day. If this not happens there is a risk that glycogen stock levels will be emptied and causes fatigue which can result in an ineffective training session.
What amount of digestible carbohydrates would need to be consumed outside of the basic diet to cover the carbohydrate requirements of training/competition?
Under carbohydrate burning are the tables you need.