Answer: At high altitude the body will get prepared for marathon.
Step-by-step explanation:
The human body is able to adapt the high altitude by long-term and immediate acclimatization. At high altitude the lack of oxygen is sensed at the carotid arteries. It causes the increase in rate of breathing or hyperpnea.
In addition at high altitude the heart beats faster, gradually the body will also compensate itself for low availability of oxygen and get prepared for marathon.