Five things that happen to your body during a marathon

1. During a marathon, the body significantly increases breathing and heart rate to supply muscles with more oxygen and nutrients, with some runners experiencing cardiac drift due to dehydration.
2. Repetitive movements cause micro-tears in muscles, particularly in the lower body, leading to inflammation and adaptation, often resulting in delayed onset muscle soreness post-race.
3. The body's core temperature rises due to energy production, triggering increased sweating and blood flow to the skin for cooling, which can lead to significant fluid and electrolyte loss.
4. Metabolism increases, initially burning glycogen for rapid energy, but these stores are finite and deplete during the race.
5. As glycogen stores diminish, the body switches to slower fat oxidation, increasing perceived effort and potentially causing runners to 'hit the wall' around 18-20 miles due to energy depletion.

IN FULL

Here’s what actually happens to your body when you run a marathon