The Effects of Exercise on Heartbeat, and the Assessment of Cardio-Vascular Fitness

David Greene

SAFETY

Do Not Run With Injuries, You Could Only Make Them Worse!

Be Careful Not To Injure Yourself Whilst Running!

Introduction

In this experiment I intend to examine the effects of exercise on heartbeat and Cardio-Vascular fitness (fitness of the heart and lungs), including pulse how long it takes to recover from a vigorous training session a ‘Bleep Test’. The measurements will range in a class of 22 boys who all have a similar diet, same age, near enough same exercise regimes; so this is not an ideal experiment because all the boys are from similar background. But to make it an accurate test I will need some sort of exercise that pushes the body (exhaustion exercise) so I chose to do the ‘Bleep Test’, which is a tape that plays beeps and the person has to run a 20m. track within the bleep. The aims of the experiment is to measure the systolic and diastolic blood pressures and heartbeat rate at rest, the recovery time after an exhaustion type exercise and the exhaustion type exercise is the ‘Bleep Test’.

Prediction

I predict in the experiment that every ones heart rate will increase by a lot, maybe about 150% in some cases. This is because when someone exercises their muscles need more oxygen to be supplied to their muscles because they are now working a lot harder so their oxygen demand is higher. The only way you can keep going is that if your heart rate goes up to supply the greater demand of oxygen to the muscles, when the heart rate goes up this means the heart pumps more times in a minute and so a greater volume of blood is pumped round the body. When your heart reaches its max heart rate it can only last for a few minutes, before the muscles demand more oxygen than the heart can provide. So after a few minutes the reactions that take place to produce energy that use oxygen and produce water and carbon dioxide start to react without oxygen (anaerobic respiration), which produces lactic acid and a lot less energy; it produces less energy because the glucose reactant does not break down fully so it does not produce as much energy as if it was to break down fully. Anaerobic respiration produces lactic acid, this builds up in your muscles and causes stitches if too much is built up. The stitches make us stop working because it hurts to do so, so this is when we drop out of the experiment. A lot of people tend to get stitches in the stomach, this is because when we exercise less blood is pumped to the digestive system (because it is needed in the muscles in the legs and other moving parts), so if we have eaten beforehand we still need to digest the food in our stomachs and because less oxygen is being sent to the stomach anaerobic respiration occurs, this build up of lactic acid then causes a stitch in the stomach.

When we drop out of the test our heart rate should be at its maximum if we did the test properly, and if not it will not be at its maximum.

If everyone tries their hardest we will get an accurate set of results with the people involved in the experiment.

Key Factors

To find out the effects of exercise on the heartbeat and to assess cardio-vascular fitness, I will do the ‘Bleep Test’ five times this is so I can get a good set of results and so I can take an accurate average. After dropping out of the bleep test I will start taking my pulse straight away for fifteen seconds; I will then multiply this fifteen by 4 so I can get a beats per minute (bp/min.), I can not take my pulse over a whole minute because I can not note the pulse without missing some pulses of the next minute.

Equipment

The equipment I will use in this experiment is:

Tape recorder
A ‘Bleep Test’ tape
A suitable track measuring 20m.
A stopwatch (with milliseconds)
Suitable clothes to run in e.g. trainers

Fair Test

This is a preview of the whole essay

Equipment

The equipment I will use in this experiment is:

Tape recorder
A ‘Bleep Test’ tape
A suitable track measuring 20m.
A stopwatch (with milliseconds)
Suitable clothes to run in e.g. trainers

Fair Test

To make it a fair test I will have to control all of the variables apart from those I want to change. So I need to keep the other variables the same throughout the five ‘Bleep Tests’ I will do. So I need it would be fair if everyone was at their maximum health, meaning that they had had a very good nights sleep and had recovered from any previous exercise or injury; this would be so every could do their best, so they couldn’t make excuses or so they were not physically tired. Then everyone was put on the same diet for a few days prior to each experiment so everyone has the same store of energy to use; so no one has a lot more energy because they eat food with more energy in it, so their muscles could go on for longer than someone else with a less energy consuming diet. Wear the same clothes, this is because certain clothes restrict some movement and others let movement occur e.g. if someone was wearing scuba gear and someone was wearing p.e. kit. The person in p.e. kit would find it easier to run. Everyone is to start collecting their results as soon as they drop out from the ‘Bleep Test’; this is so everyone starts off at their maximum heart rate. Everyone is to run on the same 20m. track at the same time; this is because if we all ran on different surfaces are data would be completely unfair e.g. if someone was running on tarmac and someone else was running in a marsh.

Method

In the experiment I aimed to collect five sets of data, but unfortunately to the lack of time I have to do a ‘Bleep Test’ I could only collect one set. The night before the experiment I went to bed earlier so I could get a good night sleep so I was not physically tired when I had to do the test. Right before we had to do the test I took my resting heart rate five times after resting for five minutes sitting down, after that I got ready to do the experiment. When the test had begun I ran on until I had to do drop out because I was tired and exhausted.

As soon I as I had dropped out I measured my maximum heart rate and then every minutes until it had returned to my resting heart rate. Later on I will then see if my prediction was right by comparing it with my results.

Obtaining

The results I managed to collect are on another page because I could not fit them on to this page.

Analysis

Altogether my results were good and quite accurate, but unfortunately due to time I could not do all five experiments but only one. However with the one experiment I did I can make a good conclusion that heart rate does indeed go up with exercise, and also breathing goes up as well.

With the results I collected, as a class there was a good variation of recovery times, maximum and resting heart rate.

The highest resting heart rate of the whole class was Charles Henry Hall who had 79 bp/min..
The lowest resting heart rate of the whole class was myself David Greene with 44 bp/min..
The highest heart rate of the whole class after exercise was Jeffrey Zhang who had a very quick heart rate of 200 just after a vigorous exercise.
The slowest heart rate of the whole class just after exercise was Redmond French who had a heart rate of 136 just after a vigorous exercise. (I have left Robert Church-Taylor and James Chanter out of my analysis because it is so obvious that their results are anomalies, other Robert would have had the slowest heart rate after a vigorous exercise with 96 bp/min. which hardly breaks a sweat).
The slowest recovery rate from the whole class after a vigorous exercise was Michael Mellows who took 12 minutes to get down to 68 bp/min. but was still 4 bp/min. off his resting heart rate; so it would have taken longer to go down by about one more minute maybe two but I am not sure so I will not write it down.
The fastest recovery rate from the whole class after a vigorous exercise was Pablo Usobiaga who took only 6 minutes to recover.

Also in the class results I have taken into account the rugby players, age, sex, border or dayboy and their home country. I have taken these into account because they are all relevant to the experiment because they can determine the level of fitness the pupil is at. If the pupil is a rugby player they do a lot of running around and get fit exercises during their practices, however if the pupil is not a rugby player he is usually less fit because the other games options are less demanding on the heart and lungs so they don’t get trained up as much. The rugby players heart should get bigger with all the training they do so the heart can pump more blood around the body and so more oxygen, because of this the body can recover quicker from exercise. If the pupil is a border they are on the same diet of food at school for up to weeks on end with only about 2 different courses to choose from at meal times, however if the pupil is a dayboy he/she can go home and have a different meal or could eat a lot of sweets when at home at become a little less healthier. If the pupil is a border they are on a similar diet because the choice is little at meal times, and the food has probably got the same amount of energy in it so if they are both on the rugby team and borders they should be of similar fitness. The pupils can be at different ages which is either a disadvantage or an advantage depending on how old you are, if a 20 year old was running against a 15 year old it is in the 20 year olds favour to win because his muscles are more developed because he has finished puberty and is now a man with much stronger muscles. Jeffrey Zhang is now 16 going on 17 in the summer term and Jose Gutierrez is 14 but only turned so in January of 2002, so Jeffrey could have an advantage of age because he could have started puberty earlier. But although I have taken into account the persons age I don’t think it matters very much with this age group. Also I took into account the persons home country, this is because some countries have a healthier diet and so the population could be averagely more healthy e.g. Americans eat a lot of junk food which is high in cholesterol which blocks the capillaries and high in fat, but on the other hand a lot of Japanese people eat seafood which is very healthy for you. However, the nationality does not matter in this experiment because we have all been on the same diet for about 2 weeks before hand, but in another experiment it might make a difference. Also I took into account the size of the person because if you get two people that play rugby but one is quite a big lad and the other skinny the skinny one should win because his muscles don’t have to move as much weight around. Finally I took into account that if people smoke their performance is usually worse because the little air sacks in the lungs become bigger air sacks and so the surface area is decreased and so less oxygen can be diffused per second; but I did not name these people for their own privacy.

In the results I did notice that all the rugby players got level 8 or above with the highest being 13. However with the people that do not do rugby the lowest was level 4 and the highest was level 6 with the exceptions of Enrique Uribe 8 and Michael Mellows 9 but these two were on the rugby squad before it had to be cut down. Also I noticed that the recovery time for the people in the rugby squad was less than 10 minutes for everyone and only one person took 10 minutes to recover everyone else on the rugby squad took 9-8 minutes. However it took the non-rugby players between 7-11 minutes to recover, only three of them took under 8 minutes to recover Jeffrey Zhang who got to level 4 took 7 minutes, Enrique Uribe who got to level 8 took 7 minutes and Pablo Usobiaga who got to level 6 took 6 minutes to recover; the other 7 of them took between 8-11 minutes to recover.

In my table of results I noticed that Jeffrey Zhang’s resting heart rate was faster than after he had done exercise. This is probably because he was nervous before the experiment and so his heart rate had risen, but after the experiment he was not nervous anymore because he had finished it and so we could see his true resting heart rate. His heart rate before the test was 75 bp/min. and his heart after the test was 48 bp/min.

In my results I compared myself to the people with the highest and lowest maximum heart rate because they showed a range of results for the whole class and although this is a number of people it is not all that different because I could have experimented on a more diverse number of people and in turn get a better average and a better assessment for my aim.

Also I noticed with the results that the pupils who did it were not from a dispersed community, they were all from the same school, were of the same sex and near the same age of each other.

Evaluation

With the method I used I think my results were accurate enough to make a reliable analysis, however there are numerous ways that I could have got more reliable and more accurate results. In my experiment I think there were no anomalies with them, but with two other peoples results I spotted most certain anomalies these were with James Chanter and Robert Church-Taylor’s results, and so I took them out of my results table. With Robert Church-Taylor’s results his resting heart rate was 68 and his maximum heart rate after what he called a vigorous exercise was 96, he only got to level 4 and took him 8 minutes to recover; he either did not measure his heart rate properly or did not put in enough effort to get his maximum heart rate and tire himself out. Also with his results his heart rate went up and down only once (80, 76, 80) and so this supports the theory that he did not measure his pulse right. With James Chanter’s result his resting heart rate was 74 and his maximum heart rate was 108, he got to level 4 and took 12 minutes to recover form it! James’ results also went up and down when recovering from the exercise: 108, 92, 92, 84, 92, 88, 92, 92, 100, 92, 88, 84 and 74. This is also most definitely an anomalous experiment and should not be used to get any results or analisation from because it is obvious he did not measure his pulse right at any time during the recover time and it took far to long to recover from only getting a level 4.

I could have made my results more accurate with some changes in my method. With my method I did the test and then as soon as I dropped out I started to measure my pulse for 15 seconds and then multiplied it by 4 to get a bp/min.. Instead of measuring my pulse for 15 seconds I could have measured it for a whole minutes and then tell someone else the bp/min for him to note down, but ideally I would have used those little sticky things they use in hospital to measure my pulse but due to lack of funding I could not buy one and I did not know anyone of whom I could borrow one. Also to make the results more accurate I could have put everyone on the same diet so they could only eat the same food, and so on the day of the experiment everyone all had the same supply of energy to use, but I could not do that because people would not agree and I could not force it upon the day pupils who could go home and eat more food anyway. The amount of rest a person gets before exercise also reflects upon hi s performance, and so ideally no one would have any exercise up to three days prior to the experiment (so they can fully recover from any lactic acid build up in the muscles), and everyone should only get a minimum and maximum of ten hours of sleep also three days prior to the experiment so no one could say they were tired and that’s why they did not do as well as the person next to him. The clothes a person wears to do exercise in also effects his/her results, because some clothes restrict movement and some allow for it to happen; and so to get accurate results form this I would put everyone in the same types of clothes and shoes so they all had they same access to move ability. Also I noticed form when I analysed the results that only a small number of people participated in the experiment and they came from a small community (from the same school), were of the same sex and near enough of the same age but all being in the same class. So to get the best results to assess cardio-vascular fitness would be to test a larger number of people, half and half with the sex’s, same ages and different types of people e.g. fishermen, rugby players (with a similar fitness regime), footballers and ballet dancers; this would be so I could get as a diverse set of results as I possibly could. Also in the experiment the track on which we ran on was not 20 metres as it should have been but 22. So we had to run an extra 2 metres on every length, this would tire us more quickly and so we would have to drop out of the experiment at an earlier stage than we would have done if it was 20 metres long. If we ran a track that was 2 metres short (18) we would run less than someone who had to run 22 and so the person running the 18 metre track would be able to run on for a longer period of time because he is having to do less running on every length.

But although I could have made my results a lot better by using different techniques, my results that I did get from the experiment I did do are accurate and reliable enough to make a relevant comment about there credibility to the aim of the experiment. This experiment did go well and in hope i have made a decent assessment on the effect of exercise on cardio-vascular fitness and the rate of recovery.