Part 4: Caffeine

How long does it take for caffeine to be completely absorbed by the GI tract

In 30-60 minutes

What is the role of adenosine in the brain and what does caffeine do to these adenosine receptors

Adenosine in the brain has NT functions & helps induce drowsiness & sleep

Caffeine is an antagonist for adenosine receptors in the brain, specifically receptors 1 and 2A

Decreasing vs increasing caffeine

Decreasing doses of caffeine is stimulating while increasing doses can cause anxiety

Non-users can reap more attention benefits

How can caffeine benefit athletic performance b/c:

• increases force of muscle contraction

• Enhanced arousal

• Decrease in pain perception

Chronic caffeine and why caffeine is not considered to be addictive

Leads to tolerance

Non-user can drink before bed w/o problem

• despite a physical dependence it does not meet criteria to be considered addictive

• you can be dependent not compulsive/addictive

What is the criteria for caffeinism

(1000 mg or + a day)

• restlessness, tachycardia, insomnia

• Difficult to distinguish from anxiety disorder

Acute tolerance of caffeine

Increases BP, RA, and water excretion & can stimulate catecholamine release from adrenal medulla

• not always seen in chronic users