Running Tip #3. Poor nutrition is the largest cause of "hitting the wall" or glycogen depletion. Focus on good foods like vegetables, fruits, whole grains, fish, and grass-fed meat and avoid refined grains, fatty meat, excess sweets or added sugar, and fried food that deplete glycogen faster and lead to weight gain. 1 extra lb = 1 extra second / mile! I love plenty of good carbs, but they should be proportional to training load, i.e less carbs with less miles during taper. Make sure to get protein within 30 minutes of finishing a hard workout or race.