Is this normal? I went to the gym for the first time a couple weeks ago. I was running on the treadmill, and you can put your hands on the hand bar and it will tell you (approximately, I suppose), your heart rate. I was running for about a half hour (I ran/walked a mile) and I was alternating between a faster run and a slow jog. I noticed that everytime I was running fast, my heart rate was pretty low. When I would slow down the treadmill, my heart rate would get much faster. Then I would speed it up again, and my heart rate would decrease. Does that seem right? Is there something wrong with me? My brother, who goes to that gym every other day, was using the exact same treadmill right before I got on it, and he said there was nothing wrong with the calculations it gave him. Thoughts? By the way, I am a 24-year-old female... I am a perfect weight for my height but my heart and muscles are kind of out of shape I think...