The activity that made my heart beat the fastest was doing the planks and in second place was jumping. The activity that made my heart beat the least was surprisingly running in place! I think that we ranked it wrong because you would think that walking would exercise your heart the least not running in place. I noticed that the changes in my heart rate were that my heart sped up when we were doing small things like walking because of the other things like jumping. I think that my heart rate increased when I was doing exercise because of my heart trying to get blood to all of my muscles that were exerting themselves. I can make an inference when I was running the mile my heart rate increased in sound and tempo.