Effect of Caffeine on Exercise
Chapter 1: Literature review
Section 1: Literature Review
Article 1: How Caffeine Improves Exercise Performance
An article published by Mawer in 2016 shared an experiment that broke down how the dose of caffeine has
correlated with the performance. In the articles, Mawer talked about a study that included multiple cyclists
given caffeine doses of 100mg, 200mg and 0mg. All Athletes were given carbohydrate-electrolyte. The study
showed that participants given doses of 100mg and 200mg had a faster track finish time than cyclists given 0mg
of caffeine. Which concluded further that caffeine has direct correlation to better performance. This is proven as
it stimulates the sympathetic nervous system, which plays a role in inhibits hunger, increases satiety, and
increases the breakdown of fat cells to be used to boost energy.
Analysis
In this experiment the independent variable is the number of caffeine doses given to each cyclist. This means
the amount of caffeine given to cyclists varied, and this was used to cause an effect which could be measured.
Therefore, in this experiment cyclists were given doses of 0mg, 100mg and 200mg in the hope that these
different number of doses will serve different severity of effect. In the experiment, the dependent variable is the
performance from the caffeine consumption from the cyclists. Therefore, the dependent variable is something
that is measured because of the effect which in this case is the caffeine consumed by each cyclist. This means
that in this experiment the dependent variable is the amount of time taken for the cyclists to complete a set
track. The experiment's aim was to see any performance changes based on the amount of caffeine they took.
This experiment had many controls that needed to be considered these included factors such as: same cycles,
Similar performance by each cyclist, same body weight, the track length is the same, Type of caffeine. Firstly, it
is mandatory to have the same cycles as the quality and mechanical qualities because they play a role in
performance when it comes to an efficient experiment. In addition, factors such as the base performance of each
athlete also need to be the same. This is because if they are all given caffeine, their personal performance may
outperform their caffeine performance, boosting discrepancies in the experiment's results.
Evaluation
This experiment clearly outlined how the effect of caffeine is correlated with performance boost for athletes.
However, the experiment failed to share factors such as heigh and weight that could play a huge role in
performance so therefore can be built further. The experiment shared how more caffeine equals more
performance boost which implies is not the case the trend is upwards until the optimal is met for each individual
where the caffeine correlation ends and therefore as the result. In addition, one thing that went well in the
experiment is the fact that the results were share from a set number of participants which mean that there was a
varied trial however there was no mention of repeats and repeats are critical to show that the experiment is
repeatable and would show same results making the results credible. However, one thing that experiment
missed out that limits its results potential is the mention of the varied athletes for example males and females if
the experiment uses different genders and can produce comparable results it is credible as males and females
have different biological built which could mean that males may retain more caffeine compared to females.
Therefore, if the caffeine effect is the same on both genders it really justifies the effect of caffeine on
experiments. Overall, the experiment shows how caffeine affects exercise and performance but does not show a
significant reasoning to why and how much is needed precisely.
Article 2: A high carbohydrate diet negates the metabolic effects of caffeine during
exercise
, Another study published by WEIR et al., in 1987 ran multiple iterations of trials that tests the correlation
between caffeine and exercise but the only change in this experiment compared to Mawer in 2016 was that
WEIR et al., tested if presence of high carbohydrates negated the effect of caffeine with the hypothesis that a
high carbohydrate diet negates the effect of caffeine during exercise. In this study WEIR et al., talked about
why this may happen as it said that when a high carbohydrate diet is consumed the free fatty acids increase
blood fatty acid to increase. Further when caffeine is ingested post carbohydrate consumption the blood free
fatty acid levels decrease then rise over time. This in theory would decrease the effect of caffeine. For the
experiment's trials, the study used runners to run a controlled track where some were given carbohydrates and
caffeine, some were given just fatty meal and the rest were given caffeine with one. This was done to run set
scenarios to see if any carbohydrates negated the effect of caffeine while exercising.
Analysis
In this experiment, the independent variable is the type of nutrients given to the athletes. This is an independent
variable because it is a cause that can have direct effect on the results that will be measured and are altered to
see trends and patterns. In this experiment the independent variable varied from just caffeine and carbohydrate
meals, fatty meal alone and caffeine with fatty meal. This is chosen to see if high carbohydrates and fatty meals
have any effect on the effects of caffeine during experiment. For the same experiment, the dependent variable
was the performance of the experiment. This is a dependent variable as it is the direct result of the independent
variable's effect. For this this experiment performance of the subjects was the dependent variables as it was
measured to see if therefore any changes in their performances compared to the control to see if any of the
dependent variables had any effect on the performance of the athletes. This is important as it shows the results
of the hypothesis that carbohydrates or even fatty meals had any effect on the effect of caffeine during exercise.
There are many control variables in the experiment, these include: similar performance of athletes, same
portions of each nutrient, same length of tracks and similar body weight of athletes. These variables must be
kept the same as it gives consistency for different facts that might affect the experiment results. The athlete's
performance needs to be kept the same as they will have a base amount of optimal performance it is important
for it to be kept the same as the effect of the nutrients will have a significant impact on them and it is important
to be kept the same to provide us with the best experiment. In addition, the same portions of nutrients should be
given in proportion to athletes with all same body weights because for optimal effect of any nutrients, there is a
specific mg/kg therefore if the athletes have similar controlled performance, similar body weight and same
nutrients would give us accurate and repeatable results as all these factors that could affect the results are
controlled. In addition, it is also important to have the same length of the track the runners run on. This is
because the performance is measured based on their running time as these athletes are runners. Therefore, if the
track lengths are the same, they will give accurate results in change in performance if the nutrients were
consumed and therefore providing reliable results.
Article 3: Caffeine increases performance and leads to a cardioprotective effect
during intense exercise in cyclists
Another study conducted by Sampaio-Jorge et al., in 2021 researched how caffeine increases performance and
additional benefits regarding cardioprotective effect during exercise, specifically in cyclists. This study shared
insights about how different dietary strategies alongside caffeine can have an effect on the security of the effect
of caffeine during exercise, this study also utilized placebos to maximize the effectiveness of the experimental
as controls are an effective way of showing effect and non-effect of a stimulant which in this cause is caffeine.
During this experiment there were 14 subjects who were all relatively highly trained cyclists. In this experiment
half were given caffeine tablets based on body weight and some were given placebo, and all made to cycle the
same track and their best times were measured. This experiment was able to show that subjects with caffeine
intake had a significant increase in performance during their exercise. This therefore supports the initial study
that caffeine does cause positive effect on exercise.
Analysis
