Question 1

Chemically, caffeine and theophylline are considered which of the following?&#10;A) Xanthine alkaloids&#10;B) Calcium channel antagonists&#10;C) Cyclic amp analogues&#10;D) ATP mimics&#10;E) None of the above

Accepted Answer

Caffeine and theophylline are both xanthine alkaloids, which are a class of psychoactive stimulants found in coffee, tea, and chocolate.

Question 2

When caffeine is at blood levels consistent with normal (non-excessive) consumption, it probably does which of the following?&#10;A) Stimulates cyclic AMP production&#10;B) Enhances calcium release from the sarcoplasmic reticulum&#10;C) Acts as an adenosine antagonist&#10;D) Increases mitochondrial ATP production&#10;E) Activates excitatory glutamate receptors in the brain

Accepted Answer

When caffeine is present in the blood at normal consumption levels, it acts as an adenosine antagonist. Adenosine is a neurotransmitter that is responsible for promoting relaxation and sleep. Caffeine blocks the action of adenosine, leading to an increase in alertness and wakefulness.

Question 3

How does caffeine promote wakefulness?&#10;A) By suppressing the HPA axis&#10;B) By acting as a powerful sympathomimetic&#10;C) By its extensive effects on metabolism, primarily in the liver&#10;D) By blocking adenosine's ability to cause drowsiness&#10;E) By helping promote oxygen delivery to sensitive tissues

Accepted Answer

Caffeine works in the brain by blocking adenosine receptors. Adenosine is a neurotransmitter that promotes sleep and suppresses arousal. When caffeine blocks these receptors, it prevents adenosine from signaling to the brain that it's time to sleep, thereby promoting wakefulness.

Question 4

During exercise, what can caffeine do? A) Significantly increase VO₂max B) Cause a lower RPE C) Significantly raise calcium levels in skeletal muscle D) Only improve endurance performance, with no effect on short burst activity E) Increase the sensitivity to pain

Accepted Answer

Caffeine can lower the rating of perceived exertion (RPE), meaning that the exercise may feel less difficult than it actually is, allowing for potentially longer or harder workouts. However, caffeine does not significantly increase VO2max or raise calcium levels in skeletal muscle. It has been shown to improve endurance performance, but can also have a positive effect on short burst activities. On the other hand, caffeine can increase sensitivity to pain, which may decrease performance.

Question 5

Caffeine can activate the HPA axis and cause some symptoms related to stress and the fight-or-flight response.

Accepted Answer

Caffeine can increase the activity of the HPA axis, leading to the release of stress hormones such as cortisol and epinephrine. This can cause symptoms such as increased heart rate, elevated blood pressure, and feelings of anxiety or agitation.

Question 6

For every increase in dose of caffeine, there is an equivalent and predictable matching increase in blood levels of epinephrine.

Accepted Answer

The relationship between caffeine intake and epinephrine levels is not linear and predictable for everyone due to individual differences in metabolism, tolerance, and sensitivity to caffeine.

Question 7

Long-term consumption of coffee has been shown to increase the risk of cardiovascular disease.

Accepted Answer

Long-term studies have shown that moderate coffee consumption (3-5 cups per day) does not increase the risk of cardiovascular disease. However, excessive coffee consumption (more than 6 cups per day) may have negative health effects.

Question 8

Regular consumers of caffeine can experience a withdrawal syndrome if they stop taking caffeine abruptly.

Accepted Answer

Regular caffeine consumers can experience symptoms such as headaches, irritability, and fatigue if they suddenly stop consuming caffeine.

Question 9

Caffeine has been removed from the WADA Prohibited List, and its use is no longer tested or monitored.

Accepted Answer

Caffeine was removed from the World Anti-Doping Agency (WADA) Prohibited List in 2004, but it is still monitored under WADA's Monitoring Program to detect patterns of misuse in sport.

Question 10

Caffeine is a potent diuretic, and it is common for endurance athletes that take caffeine to suffer from dehydration and over-heat.

Accepted Answer

Caffeine has a mild diuretic effect, but it does not typically lead to dehydration or overheating in endurance athletes when consumed in moderate amounts.

Deck 14: Caffeine