Caffeine is a forceful stimulant and is commonly used to enhance physical strength and endurance. However, there is a lot more to this phytonutrient than just its stimulatory properties. It is also categorised as a nootropic or cognitive enhancer because it is known to sensitise neurons and give mental stimulation.
Caffeine’s primary means involves working against the adenosine receptors found in the brain. Adenosine triggers sedation and calming when it works upon its receptors. Caffeine acts as a competition with adenosine, which prevents this sedative response and prompts alertness and wakefulness. It may also lead to a rise in adrenaline and also the neurotransmitters dopamine and norepinephrine which are associated with brain activity.
Caffeine can be obtained in a wide variety of food, drinks and supplements.
How much caffeine can I consume?
Well, it depends. Excluding pregnant women (where 200mg/day is considered safe), caffeine intakes from all sources up to 400 mg per day (~5.7 mg/kg bodyweight) are considered safe for the general population.
Caffeine attains maximum plasma concentration 15–120 min after ingestion. Caffeine has a half-life of 5-6 hours, which means it can be in your system for up to 12 hours.
Caffeine & Sports Performance
Will that can of Monster raise my game? Let’s see. A 2019 review by Grgic et al. delved into 21 published meta-analyses on caffeine’s effect on exercise performance.
Aerobic Endurance – YES! The exercise performed were predominantly cycling but running, rowing and swimming.
Muscular Endurance – YES!
Anaerobic Power – YES!
However, they do not seem to be as significant when compared to aerobic activity. Anaerobic exercise examples include: weightlifting, jumping rope, sprinting, HIIT
Muscular Strength – YES!
Exercise Speed – YES! This involved maximal speed during running, rowing and cycling (depicted as the maximal attained speed in exercise performance tests lasting from 45 seconds to 8 minutes that had either a set duration or a set distance).
Short-Term High-Intensity Exercise – YES! However, these effects were not as significant in comparison to other forms of exercises.
Caffeine-10 Reasons For a Thumbs Up!
It has shown to increase alertness and reduce acute fatigue
It has been reported to enhance sports performance
Caffeine obstructs the A2 receptors in the brain which can enhance dopamine levels. This can result in improving moo
Caffeine has a protective effect on liver health. It is linked with a reduced risk of elevated serum γ‐alanine aminotransferase activity, which acts directly in the liver as an A1 and A2 adenosine receptor antagonist and/or an antioxidant
It can increase energy expenditure
Consumption is associated with a reduced risk in Cardiovascular Disease
Consumption is associated with a reduction in Type 2 Diabetes
It is associated with a low-risk of developing PD (Parkinson’s disease) and is also linked with the deceleration in the progression of motor symptoms in patients with PD
It is associated with a lower risk in developing dementia. Although, more research is needed on the subject
There is a lower risk of cancer among higher caffeine consumption in comparison to lower caffeine consumption
Caffeine - 5 Things to Remember
Sleep
Caffeine can affect your sleep. As previously mentioned, caffeine has a half-life of ~4hrs so it’s best to have it earlier in the day and try not to consume more than 400mg per day.
Anxiety
These effects usually occur above the recommended daily intake.
Blood Pressure
Although it was previously mentioned that caffeine is associated with a reduced risk in heart disease, well this depends on the individual. Those with alleles for slow caffeine metabolism are reported to be at a greater risk of hypertension in comparison with those with alleles for fast caffeine metabolism. Also, individuals who have a high blood pressure are advised to be mindful of their intake.
Withdrawals
Sudden withdrawals from caffeine can potentially lead to headaches, fatigue, difficulty concentrating, nausea and mood changes
Dependency
If you find that you are highly dependent on your cup of coffee or pre-workout to get through your day/workout then you might want to take some time off caffeine and check that your sleep, stress and nutrition are in order which are the makeup of a healthy lifestyle.
In summary, the dose makes the poison.