if it is 20 calvin outside that means the that the air has about twice as much kinetic energy compared to what it had yesterday when it was only 10 calvin

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.