Caffeine Heart Rate Lab Report

The question that was tested for this Heart Rate Lab was how might caffeine affect people’s heart rate. Caffeine is supposed to affect our nervous system and brain by buzzing them. We decided to include caffeine in our lab by having one out of 2 groups of 5 people drink caffeinated soda .Then, participants completed two activities, taking their pulses after each event. The second group (B) did everything just as group A, except drink any soda. Our hopes were that pulse rates would raise higher with caffeine in the blood stream, and this lab did not disappoint.

The hypotheses for this lab stated, “If a person is given caffeinated soda, and then goes and completes an activity , their BPM should be slightly higher than somebody who has completed the activity without any soda because 1. the caffeine should definitely have an affect with heart rate , and just eating may get blood pumping in order to digest and absorb food.”

Our hypothesis was looking to be backed up by promising data, showing higher bpm from Group A than Group B, for the most part.

But there were many unsure points and errors which could have thrown the results off. The average resting rate (BPM) from Group A was 85.4 and Group B’s was 73.6. The stair climbing rate was 126.8(A) and 111.6(B) However, some contestants had unusual results, such as Britney from Group A ,whose BPM seemed unusually higher than others (114,146) and Sydney, (A) started with a very low bpm (62) which was the lowest out of all group members. Two other outliers from Group B (Kate and Ryan) started with higher resting rates by at least 10 beats more than other members from B which made the results look less and less reassuring. These standout data points made us question how accurate our hypothesis had been. This data may have had it’s rising trends for other reasons as well. From background information we later learned after conducting the experiment ,that caffeine won’t take immediate effect until 15

minutes after taken,which was unknown but key information to our experiment at the time. So while the heart rates in Group A were somewhat higher than Group B’s , the caffeine was most likely not the main cause of elevation in pulses. There are many explanations for what could have caused this like the fact that eating/drinking is an active activity and could affect the resting bpm because of all the chewing or swallowing that may have taken place before the pulses were taken . Some other errors could have been from the participants themselves , like age differences . We used 2 younger boys (our brothers) and my dad who was also in the experiment. Heart rate could vary based on their lifestyle and habits such as eating and exercising. We also don’t know what factors like stress and anxiety could have been on other group members’ minds. This could cause pulses to raise higher than normal.More errors could include how hard people ran up and down the stairs when doing the second activity. Their pulse would have definitely rose if they gave more effort despite if they drank any soda or not. Another big doubt was how accurate our results were because most individuals took their own pulses so many could have been off.
Of course there were many other ,if not minor errors, which in the end made it hard to put our data’s accuracy with our hypothesis. By the looks of our data however , it seemed that it went pretty well with our hypothesis except for the fact that the results were not caused by the caffeine but by eating itself so our hypothesis was not truly backed up by the data received. If we were to redo this experiment we would be sure to add a 15 minute time period between the ingestion of the caffeine and the activity so the caffeine would have an actual effect. We would also make sure to pick candidates who were all within range of age and size to get similar data and take pulses ourselves so we can be sure the data is right. With these corrections, the lab will hopefully give us that same result we predicted at the beginning.