No wonder the marathon is our ultimate yardstick - from cramps, to dizziness, to dehydration, those gruelling 26.2 miles reach parts other distances can't reach. And it can pay to know exactly which parts.

"Understanding the physiological processes that occur during the different stages of a marathon gives runners a better grip of the underpinnings of strategy and training and can take their running to the next level." Clare Lane, Applied Physiologist, Bath University Human Performance Centre

Eating a healthy balanced diet is important for everybody to maintain health and fitness. For sports people regular training and competition can be both physically and mentally draining, requiring energy levels to be sustained for long periods in daily training sessions, as well as other demanding activities and commitments. Your diet - the food you eat - is critical for fueling your body for regular exercise, aiding power and endurance, concentration and coordination, boosting immunity and promoting repair and a speedy recovery.