How Does Caffeine Affect Pulse Rate

Investigation Task:

Level of caffeine to affect pulse rate while performing physical activities on 15-16 year olds.

Research Question:

How does the volume of a particular energy drink – Red Bull affect one’s pulse rate?

Background Information:

The level of hormones can change a cell’s activity by binding to specific hormone receptors which can activate proteins within the cell, which will then go on to activate other enzymes that direct the cell’s function. Caffeine is a methylxanthine which acts as an anti catalyst to an enzyme called cyclic phosphodiesterase (cAMP - PDE) which is responsible for blocking the production of cAMP.

As caffeine inhibits cAMP – DPE from doing its job, the cAMP generated is increased and remains active in the cell for longer. This cAMP produced then diffuses through the cell and

activates an enzyme called kinase which produces adenosine triphosphate (ATP). The result of increase cAMP levels (due to caffeine) is increased levels of ATP which leads to an increase in the responsiveness of heart muscles causing an increasing in pulse rate.

The energy drink used, Red Bull, contains 80 mg of caffeine.

Ingredients of Energy Drink – Red Bull:
Carbonated Water, Sucrose, Glucose, Acidity Regulators (Citric Acid, Sodium, Citrates, Magnesium Carbonate), Taurine, Caffeine, Inositol, Vitamins (Niacin, Pantothenic Acid, Vitamin B6, Vitamin B12), Flavorings, Colours (Caramel 1 – Plain, Ribioflavin).

Caffeine Content: 32 mg per 100 ml

Adolescence are advised that they consume no more than 2.5 mg of caffeine per kg of body weight per day. An overdose of caffeine can lead to health risks such as obesity, sleep disturbance, bed wetting and more.

General Prediction: I predict that the consumption of higher volume of energy drink will results in the highest increase in pulse rate after physical activity.

Hypothesis:
The more energy drink that the subject consumes, the higher the subject’s pulse rate will increase after physical activity. This is because the energy drink (Red Bull) contains caffeine, which stimulates the metabolic and central nervous system.

Upon consumption, caffeine increases ATP levels in the body, which causes pulse rate to elevate.

I also predict that due to consumption of caffeine present in the energy drink, it would take longer for the pulse rate to return to its regular resting levels after physical activity. This is because the caffeine causes increased levels of cAMP and simultaneously allows the cAMP to stay active for longer. The increased levels of cAMP result in an increased level of ATP leading to an increase in pulse rate.

To investigate whether if the energy drink affects the pulse rate, I will be using 5 subjects and will be observing the effects the energy drink has on the pulse rate after physical activity. Therefore, the subjects must be of normal BMI and without any health conditions in order to make sure there are no other factors affecting the Subject’s pulse rate.

First I will record the pulse rate of the subject after performing physical activity which will give me the subject’s pulse rate after physical activity without the effect on the energy drink. After which I will make the subject perform the same but with different volumes of energy drink

consumption.