Question

An Iron Man competition takes over 8 hours to complete.

The following are some of the changes that occur to the human body during exercise:

i. increased body temperature
ii. loss of H₂O and electrolytes
iii. decreased blood pressure

How does a human body adjust to this prolonged changes during exercise (provided above) to maintain homeostasis?

Answer 1

Homeostasis refers to the maintainence of constant internal state of the body. During exercise, the body suffers from increased body temperature, loss of water and electrolytes and decreased blood pressure. All these chnges disturb the internal equilibrium of the body. As such, there are certain measures put in place so as to maintain the homeostasis in the body. Sweating, heavy breathing and increased heart beat are some of these measures that are not only a sign of a good work-out but also a necessity for regulating the body equilibrium. The adjustment measures for maintaining homeostasis are described as below:

• Increased Body Temperature: Increase in body temperature during exercise is a result of consumption of energy by body, the byproducts of which are primarily water, CO₂, and heat. This heat released due to consumption of energy is responsible for elevated body temperature. One method to maintain homeostasis in body temperature is sweating. The evaporation of sweat has a cooling effect on body that brings down the body temperature to a more normal level after exercise. Another process to maintain body temperature is dilation of blood vessels in skin. This allows more blood to flow to the surface of the body causing heat dispersal.
• Loss of H₂O and electrolytes: Sweating is one process through which body can regulate it's temperature during exercise. However, prolonged sweating without any replenishment can cause dehydration due to loss of water and electrolytes. Dehydration can result in decreased blood volume, which can impair blood flow to skin and cause the body to become overheated. The result will be impaired muscular strength and endurance, decreased alertness and increased risk of injury. As such, it is essential to drink proper fluids in order to maintain the process of homeostasis.
• Decreased Blood Pressure: A slight increase in blood pressure during exercise is a result of increased breathing rate and heart rate and results in increased efficiency of nutrient and energy delivery to active muscles. This increased blood-pressure returns to normal, i.e., decreases after the exercise period is over by dilation of the previously constricted blood vessels.