I am an active 16 year old... I have ridden a century before and I exercise at least 3 times a week. While doing hill repeats on my bike and running, I have taken my max heart rate to be about 240. I take it by hand and I have done it enough times to know I am not counting wrong. I can't find anybody with a mac hr like this... Is this good? bad? dangerous?
Could be your heart rate just tends to be on the high side. If you don't have any discomfort or trouble breathing and you are able to return to a normal resting heart rate within a reasonable amount of time after stopping, I would guess it's probably not a big deal. My doctor gave me similar advice a few weeks ago after I asked him why my resting heart rate seems high even though I'm in pretty good shape.
Plus - I don't take my max heart rate regularly now, but I remember doing so when I was a runner in high school and it was consistently on the high side. That 220-age formula never worked for me.
Sounds like your HRM got sidetracked by interferences by a high voltage line or a passing vehicle. It happens sometimes to me during a ride; my Polar jumps to 240 (its max reading) for a little bit then comes down to normal.
I am 36 and I can get my max heart rate to go 230 plus.
Granted, it is kind of artificially induced- (Old San Marcos, Santa Barbara, 42-17 gearing) but nevertheless I can hold it. The only side effect is slightly blurred vision under load. When I was younger, I had a massively high max rate.
At 16 years of age this is totally believable.
240 is not too high, by any means. Back in college that was my max when I was swimming at a high level. One of the guys over at Cal Tech had a max of 280. Now the other side is that when I was swimming when we would do heart rate work (swim 50 or 100 years all out, take heart rate and take it again every few seconds) when it got down to 150 it was time to go again. Getting down to 150 never took more than 20 seconds or so. Max rate is not sustainable.
BTW that is a max rate taking the pulse for 5 seconds. Taking it for 10 gives a much lower rate as by the end of 10 seconds the heart rate has dropped significantly.