Caffeine

Question 1

What is caffeine? (1,3…, WADA, sources)

Answer 1

• 1,3,7-trimethylxanthine -> metabolised in the liver
• Commonly consumed
• Removed from WADA list in 2004 (previously 12ug/mL limit)
• Sources, coffee, coke, dark chocolate

Question 2

What is the bio-availability of caffeine?

Answer 2

• Peak blood caffeine concentrations typically occur approx 60 mins after ingestion in a dose-dependant way
• However, benefits from caffeine can occur soon after intake

Question 3

What are the effects of caffeine?

Answer 3

• Improved vigilance and alertness
• Reduced perception of effort
• Reduced fatigue and pain

= Improved performance

Question 4

How does Caffeine work? (Binding, stimulates…, stimulates…)

Answer 4

• Caffeine prevents adenosine binding and therefore delays fatigue
• Caffeine stimulates lipolysis, directly and via an increase in adrenaline
• Caffeine stimulates calcium release which is important for muscle contraction

Question 5

What happens to substrate metabolism when carbohydrates are consumed with caffeine?

Answer 5

No effect, but still beneficial to performance

Question 6

Different types of caffeine sources?

Answer 6

• Coffee
• Caffeinated gum, more effective as bypasses the gut (increased absorption, decreased GI distress)
• Faster caffeine absorption with gum

Question 7

What is the optimal caffeine dose?

Answer 7

• 1.5 to 3mg/kg, so for an 80kg athlete it would be 120-240mg caffeine

Question 8

When is the best time to consume caffeine?

Answer 8

• Usually 40-60 mins before the event or exercise
• Throughout event at lower doses (1.5mg/kg)
• Late before an event or before an important stage of the event (100-200mg)
• Consider sleep

Question 9

Does caffeine habitual consumption affect ergogenic effects? If so when does it?

Answer 9

• Caffeine habitual consumption does not affect ergogenic effects, only when high doses are consumed (6mg/kg BM)

Question 10

Co-ingestion with caffeine?

Answer 10

• Co-ingestion with CHO is ergogenic and offers greater performance improvements than CHO alone. Ingesting caffeine in drinks contributes to hydration

Question 11

When should you consider caffeine use?

Answer 11

• Endurance sports (> 60mins)
• Brief sustained high-intensity sports (1-60mins)
• Team and intermittent sports
• Single efforts involving strength or power
• Pre-training energy boost if carrying fatigue into a session

Question 12

What are the risks of caffeine consumption?

Answer 12

• Sleep (consume 5 hours before sleep)
• Hydration

Question 13

Other side effects of caffeine?

Answer 13

• At moderate and high doses of caffeine (>6-9mg/kg) other side effects can occur: anxiety, jitters, insomnia
• There is a dependency to caffeine

Question 14

Safety issues with caffeine consumption?

Answer 14

• Pure or highly concentrated caffeine can be potentially lethal
• The use of caffeine by children carries greater risk