At this time of year you may be training for a Spring race, perhaps a marathon or a shorter distance. You’ll have a training plan that leads you to increase your mileage and/or put in some speed sessions. If you are increasing your training mileage you’ll need more energy. If you are training harder, and for longer, you’ll be increasing the physiological stresses on your body and you need to take precautions against those stresses having adverse effects on your overall health.