Problem 14 - Biology: The Essentials

Question

The concentration of \(\mathrm{O}_{2}\) in the atmosphere declines with increasing elevation. Why do you think the times of endurance events at the 1968 Olympics, held in Mexico City (elevation: \(2200 \mathrm{m}\) ), were relatively slow?

Step-by-Step Solution

Answer

The reduced oxygen concentration at Mexico City's high elevation impaired athletes' endurance, resulting in slower times at the 1968 Olympics.

Step 1: Understanding Elevation Impact on Oxygen Concentration

At higher elevations, the air pressure decreases, leading to a lower concentration of oxygen molecules in each breath taken. This means that although the percentage of oxygen in the air remains the same (about 21%), there are fewer oxygen molecules per volume of air.

Step 2: Effect of Reduced Oxygen on Athletic Performance

During endurance events, athletes rely heavily on aerobic respiration, which requires oxygen to produce energy efficiently. When there's less oxygen available, the body struggles to maintain high levels of performance due to reduced energy production.

Step 3: Specific Conditions in Mexico City

Mexico City sits at an elevation of 2200 meters (approximately 7218 feet) above sea level. At this elevation, the lower oxygen concentration means that athletes' bodies receive less oxygen with every breath, making it harder to perform at peak efficiency.

Step 4: Conclusion: Why Times Were Slower

Given the reduction in available oxygen at Mexico City's elevation, athletes' endurance was affected. This led to slower times in endurance events during the 1968 Olympics, as their bodies couldn't sustain the same level of performance as at lower elevations.

Key Concepts

oxygen concentration

The atmosphere is composed of around 21% oxygen, but at higher elevations, the total number of air molecules per breath is reduced.
At sea level, the pressure is higher, meaning more oxygen molecules are packed into each breath.
This is crucial for athletes because oxygen is vital for aerobic respiration.

• Oxygen is used by the body's cells to produce energy through a process known as cellular respiration.
• At higher elevations, the reduced air pressure means fewer oxygen molecules.
• This results in less oxygen being transported to muscles and organs, impairing performance.

Understanding this principle is key to grasping why athletes struggle more at higher elevations.

altitude impact

Altitude directly affects both the physical environment and physiological responses of the body.
When athletes compete at higher altitudes, like Mexico City's 2200 meters, they are exposed to a lower concentration of oxygen.

• This can cause altitude sickness, where symptoms range from headaches to more severe forms affecting performance.
• The body requires time to acclimate to higher altitudes in order to produce more red blood cells which help carry oxygen efficiently.
• Without sufficient acclimatization, athletes may experience decreased stamina and endurance.

It's evident that training and competing at high altitudes without proper acclimatization can lead to notable declines in performance.

endurance events impact

Endurance events, such as marathons and long-distance cycling, rely heavily on a steady supply of oxygen.
At Mexico City's high elevation, the limited oxygen availability greatly impacted athletes' performance during the 1968 Olympics.

• Endurance sports demand sustained aerobic respiration, which becomes less efficient with less oxygen.
• Athletes may tire more quickly and cannot maintain their usual pace.
• The body may shift more towards anaerobic metabolism, which is less efficient and produces more lactic acid, leading to muscle fatigue.

The combination of these effects explains why endurance event times were notably slower at the high elevation of Mexico City.