Heart Rate vs. Holding your Breath

Question:
How is one's heart rate affected by holding his or her breath?


Main Idea:
Being a swimmer, I always hold my breath, so I was wondering if holding one's breath affects his or her heart rate. I decided to test this out on myself and some of my swimming friends.


Hypothesis:
I think that holding one's breath will affect one's heart rate because holding one's breath lets less oxygen to one's heart, so one's heart works harder to get oxygen, making it pump faster.

Procedure:
Get a stopwatch, recording materials, and 5 people (swimmers) to test. Take each person’s pulse for a minute three times and average their numbers. Then, have each person hold their breath for 25 seconds. Immediately after, take their pulse, repeating that two more times.


Results:
When I did my experiment, I found some very interesting information. Person number one had a normal heart rate averaged to about 80 beats per minute, and their pulse, after holding their breath, was about 87 beats per minute. Person number two had a normal pulse averaging 82 beats per minute, with a pulse of 85 bpm after holding their breath. Person number three had a normal heart rate at about 79 bpm, and their pulse after holding their breath was about 98 bpm. Person four’s normal pulse averaged 67 bpm and 74 bpm after no breathing. Last, Person five averaged about 74 beats per minute at rest, and 85 bpm after holding their breath. Over all, the beats per minute sped up, averaging a faster speed. On average, the difference between the regular pulses and their pulses after holding their breaths was 9 beats per minute.





Graphs:







Conclusion:
According to my experiment’s results, my hypothesis was correct, holding their breath did affect a person’s heart rate. Comparing the regular heart rates and the heart rates after holding their breath, the average difference was nine beats per minute. Using this information, we can conclude that the longer someone holds their breath, the faster their heart will beat. But, not everyone's heart rate changed by the same amount, they varied between the different people. No matter what, though, their pulses did speed up some. Now I know that at swim practice, when I hold my breath, my heart rate gets faster.