The average human heart beats about 3 billion times and then it stops. The logic of doing exercise which increases the speed at which your heart beats is that after you finish exercising your heart will beat slower than it would have if you hadn't exercised at all. So although you'll use up a whole bunch of beats in that hour of aerobics, you'll more than regain the number of beats you lost in the 23 hours until your next workout. If you exercise regularly it will likely take you more years to reach 3 billion beats.
It's a good theory.
My sister is a swimmer. She loves to race and she trains hard. One of the ways she trains endurance is that she will time herself swimming a given distance as fast as she can. She then immediately takes her pulse. Instead of trying to swim faster the next time, she tries to swim the same distance in the same time, but with a lower heart rate.
Chinese martial arts, particularly the internal arts of bagua, xingyi, and taijiquan, use a simular strategy during the summer months. We try to practice as fast as we can without increasing our heart rates. Some practitioners actually take their pulse in the "play the pipa" posture or another posture where the fingers go to the wrist. But that isn't necessary.
With a little practice it is possible to become very sensitive to the feeling of the pores of your skin opening and closing. You can in fact gain some control over this process, but simply monitoring your pores will tell you if your heart rate is increasing. Of course the pores open to release sweat, and that is what is meant by the proscription to "practice not sweating."
Another way to lower your heart rate, improve your stamina and perhaps lengthen your life span is to attend to the center of your palms. The acupuncture point on the center of your palm is actually about one inch in diameter. It is called the Laogong point (Pericardium 8) and it is associated with the heart. (The name Laogong means "palace of toil.") The center of the palm should remain relaxed. If it hardens, it is likely that your heart is working harder. You can feel your heart in your palms, you can feel an increase in blood surge. You can even feel your pulse continuously while you are doing the form, but that isn't recommended because it requires excessive concentration, which isn't very relaxing.
In bagua, xingyi, and taijiquan (most obviously in the movement lu), the center of the palm is actually pulled back. This can be done manually by expanding the elbow which creates a vaccum which then sucks the center of the palm back up toward the elbow. But that just helps you get the feeling. In actual practice the martial arts postures allow the heart to move effortlessly backwards and down (the kidneys move forward and up) creating a feeling of connectedness between your palms and your heart.
Note: There is no way someone with this knowledge could get carpel tunnel syndrome.