The importance of monitoring your heart rate

I've learned a lot about exercising effectively. It's helped immensely in keeping me pushing the limits of my endurance, and to do so without exhausting myself. Most importantly, it's keeping me burning fat instead of glucose, which is terribly easy to do if you're not watching the numbers.

Here's what I've learned:

• Use a chest heart rate monitor. If you're going to do any sort of regular cardiovascular exercise, it's worth your while to get a chest-strap-style heart rate monitor. The treadmills at the gym have built-in heart rate sensors (metal pads built into the handles) but they're fantastically inaccurate and don't work unless you're grabbing them. I've seen them be up to 30% off. I've got a Polar F6, which will alarm if you stray outside your target zone, and which remembers exercise statistics for a few weeks. It's worthwhile getting one that either warns when your heart rate hits a set limit, or that records the maximum reached.
  
• Calculate your heart rate zones. Accurately monitoring your heart rate is useless unless you know what to target. You can find a handful of these on the web—but the accurate ones require knowing your resting heart rate, which you can really only measure by taking your rate after a long period of rest. This calculator gave me results nearly identical to what my personal trainer came up with.
  
• Stick in the aerobic range. This really applies when you're trying to lose weight; while you're in your aerobic zone (143-162bpm for me) a significant portion (80%? I forget) of your energy is coming directly from stored fat instead of from glucose in the blood. Stray into the anaerobic zone, and you're burning mostly glucose.
  
• Tailor your exercise to fit. I set the treadmill up for 35 minutes of speed intervals (2:20 at 5.5mph, then 2:20 at 3.8mph, and repeat) and that keeps my heart rate right in the desired region (~165bpm for me). It's important to bring your rate up to your target slowly—I typically don't hit 165 until about ten minutes into the routine.
  
• Always be aware of your limits. Before I really started this program, I've seen my heart rate spike to over 180bpm when I was focused on pushing myself. Bad idea.
  
• Remember to cool down. It's always a good idea to let your heart rate fall down into the low 130s before stopping whatever you're doing. Even lower if you're feeling woozy.
  

So those are the important points. When I understood where I should be exercising to work my heart most effectively, I found I could exercise for far longer than when simply trying to "squeeze in a good workout." It makes a world of difference if you're trying to do this sort of thing regularly.

Note: My monitor doesn't give an awesome chart like the one at the top of this article, but that would be totally sweet.