The aim of the project is to determine the effects of caffeine on cardiac output. The study will examine the effects of caffeine ingested through a caffeinated sports drink and monitor its effects on blood pressure (BP) and heart rate (HR) before and after exercise. Caffeine is a one of the most frequently consumed drugs in the world. It is estimated that an average person consumes 70 mg per day (1). Caffeine has physiological and psychological effects, predominantly due to the inhibitory effects of adenosine, which acts as an inhibitory neurotransmitter in the central nervous system (2). Adenosine also has vasodilator effects. The consumption of caffeine may increase blood pressure ...view middle of the document...
Adenosine is a very important neurotransmitter that is found everywhere in the body because of its role in adenosine triphosphate (ATP) energy producing mechanism. It is also suggested that adenosine has a role in blood pressure and heart rate regulation (6).
Caffeine is one of the most frequently consumed drugs in the world. The amount of coffee consumed globally is estimated to be around 120,000 tons per year (4). Caffeinated sports drinks are commonly consumed by athletes around the world before exercise to enhance athletic performance. In the athletic world, up until 2004 caffeine was banned from the Olympics, with athletes being limited to 12 mg/mL in urine. A survey done by the International Journal of Sport Nutrition stated that 73% of athletes in NCAA Division 1 football consume caffeinated energy drinks on a regular basis (5).
Research has shown that energy drinks can lead to many mental and physical health problems. In 2012 the FDA related 40 illnesses and five deaths linked to a popular energy drink. The use of these substances is growing each year, especially among the younger populations. With the increased consumption of these caffeinated drinks, it is becoming increasingly important to study the potential effects these substances may be causing to public health.
The proposed research project is a phase 3 randomized study. Thirty participants with ages ranging from 18-30 will be chosen from the island. The thirty participants will then be randomized into two groups using random.org. The first group is the control group and they will be consuming 250 mL of a decaffeinated energy drink. The second group is the treatment group; each participant will consume 250 mL caffeinated energy drink. Once each participant consumes their allocated beverage, their heart rate and blood pressure (systolic/diastolic) measurements will be tested. Following the baseline heart rate and blood pressure testing, each participant will run a total of 1 km. After completion of the run, their heart rate and blood pressure measurements will be taken again. The exclusions for the participants include: Overweight, pregnancy, pre-existing conditions such as hypertension, heart disease, diabetes. Inclusions for the study include healthy men and women aged between 18-30.
The first statistical test to be conducted is a power analysis using the g-power program. A power analysis is conducted to determine the probability of finding a statistically significant effect assuming a real effect in the population.
A previous study conducted demonstrated the effect of caffeine on ambulatory blood pressure, heart rate, and mood in coffee drinkers. Heart rate in the caffeine group displayed a mean 65.5 beats/min and a standard deviation of 13.6 The placebo group had a mean of 66.4 beats/min and a standard deviation of 10.6 (7). A power analysis was conducted and displayed an effect size of 1.09 and...