The more intense your workout, the more your body relies on carbohydrates to fuel it. Duration and intensity affect the degree to which carbohydrates and fat contribute to overall energy production. Review the following statements on the effect that intensity and duration have on glucose and glycogen use and select all those that apply. Select all that apply. View Available Hint(s) Select all that apply. Blood glucose and muscle glycogen contribute less than a third of the energy needed to sustain high-intensity exercises. Completely depleting your glycogen stores will result in "hitting the wall." Lactate can be used for energy. Stored muscle glycogen is not used for energy during low- to moderate-intensity physical activity.