Question

A myth among competitive swimmers is that they should hyperventilate before a race, because that “loads them up” on oxygen, which will allow them to hold their breath for a longer time underwater. This myth is actually true, but not for the reason they think. In reality, some swimmers who have done this have lost consciousness and drowned.

a. What is the benefit of hyperventilation on breath holding?

b. What accounts for the loss of consciousness?

Answer 1

a) The hyper ventilation reduces the body's carbon dioxide content. The swimmer can withhold in under water for longer duration and it can be life threatening sometimes.

b) Low carbon dioxide level in the body leads to narrowing of blood vessels that supply to the brain. This reduction in the blood supply to the brain leads to symptoms like light headness . Severe hyper ventilation leads to loss of conciousness if the amount of carbon dioxide in the body is very less.