Which type of radioactivity would be most dangerous if you were exposed to it from a source inside of your body?

Most of the radiation that is emitted by the human body is in the infrared region and is mainly at the wave length of 12 micron hope this helps!

the more fit you are, the faster the recovery. your heart rate drops most sharply in the first minute after you stop exercising; it should then fall about 20 beats a minute—a drop of less than 12 beats a minute is considered abnormal. this “recovery heart rate” is measured as part of an exercise stress test.