Biology exp


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Biology exp

  1. 1.  effect of exercise on  Investigating the heart rate Giacomo Cetta Giacomo Cetta  
  2. 2. DesignResearch QuestionThe research question of our biology class practical is: how does exercise affect theintensity of the heart beat? This question will help us during the investigation stage andthe practical part of our experiment. The heart, pumps blood to all the body, we needblood because it carries oxygen to all the parts of the body. But what happens to the heartwhen we do exercise? To find this out, we will measure our heart rate at rest, and thenafter doing exercise, we will also measure the time that our heart takes to go back to itsoriginal rate.HypothesisI have an idea of what will happen to our heart beat after the exercise. I think that ourheart rate will increase, so if at rest we do 69 beats per minute, on exercise we will do 110beats. This is because the demand of oxygen from our body, increases since we will needmore oxygen to make our body work under exercise, and this oxygen will be pumped bythe heart to the body by arteries. To recover instead, it will not take a lot because as soonas you stop exercising, we spend one minute taking deep breaths that gives us a lot ofspare oxygen that makes us recover in not more than three minutes.Equipment Chronometer (for keeping time of the duration of the exercise) Pen and paper (for writing the data) Calculator (for measuring the heart rate change)VariablesTo make this experiment a “fair experiment”, we have to count all the dependentvariables, independent variables and all the controlled variables. The dependent variablesare the variables that we measure, which are the change in heart rate (resting andexercise), and the speed of recovery (after exercise). The independent variables are thevariables that we change, so we have to count if people exercise more than five hours aweek or less. If people exercise more than five hours, their heart is more trained to doexercise, so their heart beat will be less frequent and their speed of recovery will be faster.The last, are the controlled variables. These variables make the test fair and they arevariables that we control. For our experiment, our controlled variables are: the samedistance and age, the same type of activity, and the same gender.MethodThe first thing I need to do with my group is to draw a rough table on which I can write theresults. Then we had to decide what exercise we will do for the experiment on the heartbeat. We decided to: go up and down parts of the stairs for ten times. Done that, we can
  3. 3. start to fill our table with our heart rate at rest; We measure how many heart beats wehave in one minute.Then with my group we can start doing the actual practical. As soon as it ends we carefullymeasure our heart rate, even in this case the time that we measure the beats of the heartis one minute. Then for measuring the recovery time, we all sit down so we are sure thatwe don’t move any more and our body completely rests. To be sure that we completelyrecover, we measure our heart beat every minute for eleven minutes.The last part of the practical will be to measure the heart rate change, which is measuredby taking away the at rest heart rate from the after exercise heart rate.Analysis Valentina David Giacomo BeatriceAt Rest 66 60 72 84After Exercise 96 120 150 168+1 minute 87 112 146 163+2 minute 81 104 139 154+3 minute 74 97 132 147+4 minute 69 91 126 141+5 minute 65 83 119 135+6 minutes 65 77 111 129+7 minutes 65 69 97 116+8 minutes 64 62 93 108+9 minutes 65 60 84 95+10 minutes 65 60 78 89+11 minutes 65 60 70 83H. R. Change 96-66=30 120-60=78 150-72=78 168-84=84
  4. 4. Heart Beat Graph 180 160 140 120 100 80 Valentina 60 David 40 Giacomo 20 Beatrice 0ConclusionThe first thing to say is that my hypothesis was partially wrong, since I said that afterexercise the heart beat would increase and it did. But I said that in no more than threeminutes we would had recover our original heart beat instead it took eleven minutes. So Ilearned that the heart rate takes a lot of time to recover from an exercise.EvaluationI think my method worked very well since the results of the practical were possible asresults. We also made sure that the recovery part was the same for every one since wewere all sitting down. We also counted all the possible variables, so I think that we couldn’thad improved it in anyway. Maybe the only weakness was the keeping the count of theheart beat that we did by ourselves by placing our finger on our chest or on our wrist or onour neck, here, maybe someone didn’t feel the exact number of beats.