Conclusion: My hypothesis was correct. The amount of caffeine given to the individual did increase their heart rate. The more caffeine given, the higher the heart rate got. The human being's average heart rate without any caffeine was 88.34 beats per minute(BPM). After one pill of caffeine, 200mg, their heart rate increased to an average of 92.67 BPM. The difference between the two is 4.33 BPM. The second trial was for 1 1/2 caffeine pills, a total of 300mg. The average heart rate was 108.34 BPM. The difference between 200mg and 300mg of caffeine is 15.67 BPM. The last trial was 2 caffeine pills, equivalent to 400mg of caffeine. The average for 400mg of caffeine was 119.67. But, the difference between 400mg to the initial no caffeine is a whopping 31.33 BPM! That is a very large difference. Talking to my mother who is a RN-BSN at Capital Medical Center, she explained to me how it is very unhealthy to consume 400mg of caffeine a day. The average American only consumes around 200mg of caffeine per day through their intake of coffee and soda. In conclusion, yes, caffeine does affect the heart rate by increasing the beats per minute.