I will start the experiment by taking the subjects resting heart rate. Then I will make the subject do step-ups at their own pace for one minute with no weights. I will take their pulse rate straight after they finish the exercise. That exercise is classed as the lightest training. I will allow a resting of anything up to 10 minutes to allow the subject's heart rate to get down to around the resting heart rate it was before. After that I will take the resting heart rate again and make my subject do the same thing except they will be carrying 1 Kg weights in each hand, letting them just hang by the side of them. Then I will take their heart rate again, straight after they finish. I will do this same thing two more times, the only difference being the different intensities of exercise. The next level will be doing the step ups with the weights, but I will be pumping my arms as well. It is proven that when doing exercise, raising your hands above your shoulders increase your heart rate.
I will be taking two readings when I do the experiment. One will be the resting heart rate, the other being the heart rate straight after the exercise. I will be taking down the heart rate of my subject and compare them to try and come to a conclusion.
I predict the harder the subject exercises, the higher the subjects heart rate would be. The blood has to be pumped round the body quicker by the heart. There are several reasons why this happens. Before and during the early stages of exercise the sympathetic nervous system is alerted and adrenaline is secreted in to the bloodstream. Triggered by impulses from the brain before exercise, the heart beats faster and general constriction of the arterioles except for those serving vital organs so that the blood under high pressure is diverted to the active muscles.
The metabolic rate increases. This is caused by the shortage of ATP. The increased metabolic rate results in carbon dioxide building up in muscle tissue. If the level of carbon dioxide builds up then this is monitored by chemoreceptors. This makes adjustments in the ventilation rate because you need more oxygen to replace the carbon dioxide. The heart rate increases to carry the waste away and replace it with oxygen quicker.
Rapid movement of limbs stimulates receptors in the skeletal muscles and tendons. These transmit impulses to the heart, leading to a further increase in the heart rate.
I will repeat the experiment because the first time the subjects heart rate might be faster than normal because of the anticipation of the experiment and they might get a bit excited. I will average the two reading to make it fair. I have looked into other resources for my plan, I got the information from a book called: Biology Principles and processes- Authors- Michael Roberts, Michael Reiss, Grace Monger Pg.333.
Results
Repeat results
Average Results
Conclusion
There is a genuine pattern in my results. My prediction I made earlier was correct, and that was the more intense the exercise, the faster the subjects heart rate. The reason this happens is because when you start moving at a faster pace the body uses up more oxygen, so therefore the body needs to provide more oxygen to replace it with the increasing carbon dioxide building up in the muscles. The reading on level 4 jumps up abit more than any of the other readings this is because it is the first time that the subject is doing step ups as fast as they can. This makes them crave more oxygen. Which makes the heart beat faster to get the oxygen to the muscles where it is needed.
Evaluation
The evidence that I have collected during this experiment is enough to enable a firm conclusion to be drawn. That conclusion is the harder the exercise you do the faster the heartbeats. There were some factors beyond my control that could have affected my results. They were, the temperature outside on the two separate occasions, I did my first run through of the experiment and the repeat experiment. The subject's fitness could have changed over the period between the first run through and the repeat experiment. I could have used a heartbeat monitor to accurately measure the subject's heartbeat. To improve my investigation I could have tested more people and compare the fitness. I could also take a skin temperature reading which could tell me if people get hotter or colder doing exercise.
