How does exercise affect heart rate?

The first 200 words of this essay...

How does exercise affect heart rate?

Aim

The aim of this experiment is to investigate how exercise affects heart rate. I am going to record my resting heart rate, then exercise for 30 seconds , then 1 minute and increase the period of exercise by 30 seconds until I am exercising for three minutes without stopping . I will does this twice and take an average

Prediction

I predict that my heart rate will increase as a result of exercise. I think that there will be a slight increase to begin with, but as the body has to work harder I think that the heart will then increase at a faster rate. This is because my body need s more oxygen because it is burning energy through respiration which gives you energy from sugar and oxygen and you need more of this for your muscles when you exercise.

Sugar + oxygen =energy +oxygen+ carbon dioxide

Compared to when I am resting I need more food and oxygen

Variables

I will change the periods of exercise, I will measure my pulse rate resting and after exercise and take an