What is caffeine?
Caffeine is described a drug, a natural stimulant that ”stimulates” the central nervous system.
It is found in products such as – tea, coffee, soft drinks, energy drinks, cocoa products and can be bought in the form of tablets and powder.
Why are people taking caffeine to improve exercise performance?
There are a number of reasons people are using caffeine. One major reason as to why – is to improve exercise performance. This includes endurance, high intensity, and strength/power performance.
What does caffeine do in the body?
There are a few processes that have been mentioned to describe how caffeine acts on our central nervous system:
- Inhibits adenosine receptors – adenosine, is a chemical that slows activity of neurons, and makes us feel sleepy when it binds to receptors. Caffeine acts as an antagonist (competitor for the adenosine receptor) reducing adenosine’s ability to bind to it’s receptor, making us more alert.
- Activates noradrenaline neurons – whose main role is to prepare the brain and body for action.
- Affects levels of dopamine in blood – it is thought that caffeine increases the amount of dopamine in our brain, by increasing receptor availability – dopamine is associated with promoting wakefulness and alertness.
The effect on Strength & Power Performance
Caffeine supplementation increases both – upper and lower body strength, improving 1RM of back squat & bench press of participants.
Limitations of these studies: both studies only supplemented caffeine at a rate 6mg per kg of body weight. For a 70kg individual, this would equate to 420mg of caffeine having to be taken – which is over the daily recommended safe intake for adults.
The effect on High Intensity Performance
Caffeine doses ranging from 3-6 mg per kg of body weight have allowed improvement in high-intensity aerobic exercise.
Caffeine is told to be ingested 30-60 minutes before exercise, as it is suggested that it reaches a peak (highest level) in the blood within 30-60 minutes, and this is when you’re most likely to experience the full effects of caffeine.
The effect on Endurance Based Performance
After caffeine ingestion,
- time to exhaustion (the amount of time remaining before work cannot be maintained) and
- performance time
been were boosted in both elite runners and cyclists.
Recommendations for caffeine consumption
The European Food Standards Agency (EFSA) confirmed that up to 3mg per kg of body weight for children, and 400mg per kg of body weight for adults is safe to consume per day.
The exact amount of caffeine in any food or drink will depend on the recipe and method used to make it, but the typical amounts in the following –
- Cup of coffee (200ml) – 90mg
- Espresso (60ml) – 80mg
- Energy drink (500ml) – 160mg
- Cup of tea (220ml) – 50mg
- Plain chocolate (50g) – 25mg
- Can of coke (330ml) – 40mg
Possible Side Effects
Restlessness, headaches nausea, vomiting, increased heart rate, fever, irritability.
Long term use of caffeine can cause dependence, and addiction.
People who stop drinking caffeine abruptly can suffer symptoms & experience cravings. To minimise symptoms and cravings, slowly reduce your caffeine intake each day.
Conclusion
Caffeine can be very effective to improve performance – whether strength, endure or high intensity based and could benefit your future workouts.
A minimum dose of 200mg should produce some improvements in performance (based on 3mg per for 65kg individual) , and dosage should not exceed 400mg (due to recommendations). This should typically be taken around 30-60 minutes prior to exercise to see full effects.