Heart rate monitors are a funny thing – they can be completely useless or extremely valuable depending on how you use them. First, let’s get the wrong way to use one off the table. With rare exceptions you don’t need to worry about “heart rate zones” and spending your training time worrying about keeping your heart rate in one.
Despite what those little books that come with most heart rate monitors tell you, heart rate zones are the wrong way to use a heart rate monitor because of one simple fact – that little formula of (220-Your Age= Max Heart Rate) is wrong for most people and was never intended to be used on a wide spread basis by the guys who invented it. In yet another example of “fitness science gone wild” someone got a hold of something and completely misused it, resulting in a lot of people trying to keep their heart rate at a certain percentage of the wrong number.
Unless you do a true Max Hear t Rate test you don’t really know what that number is, which makes training based on zones derived from it worthless. However, there are 3 uses for a heart rate (HR) monitor that still makes it a “must have” tool in your toolbox.
1) To record your Max HR and Recovery HR during intervals. Here is the funny thing about intervals – they will always suck. You will never get to the point where they feel “easy” and so without some sort of objective feedback as to how your body is responding you may feel like you are not improving. I have all of my clients record the highest heart rate they achieve and what their heart rate is dropping back down to during the recovery periods when doing intervals with a pre-set work and rest period, giving you insight into how your body is responding to the training.
If you see that your HR is not maxing out as high and/ or that your recovery HR is dropping down lower then you know that you are improving your cardio fitness no matter how you feel physically. Add in some way to determine how hard you are working (speed, power or RPMs) and you have even more useful data to look at – lower heart rates at the same intensity level or achieving a higher intensity at the same heart rates is another sign of progress.
2) To determine how long to rest between intervals. Some intervals have pre-set work and rest periods which require you to go again no matter how much you have recovered. However, this method usually results in you resting too long during the first few intervals and then not recovering enough to give a max effort on the last few intervals. Sometimes you want to let your HR drop back down a certain amount before going again, resulting in a workout that is more specific to your physiology and is tailor made for you.
The two numbers that are usually used when doing this are letting your HR drop back down by 50 beats per minute or letting it drop back down to 120 beats per minute. I’ll be honest and let you know up front that I don’t know the exact “science” behind these numbers but I do know from both research into what other coaches do and my own experience that these numbers seem to do the trick. If your HR is getting over 175 bpm then use the “drop by 50 bpm” method works well, otherwise use the “drop back down to 120 bpm” method.
3) To make sure that your recovery workout is really a recovery workout. Recovery does not happen by sitting on the couch playing video games – your body will recover faster with light activity than with no activity at all. One of the best ways to help your body recover is to go on a recovery ride or run. However, for it to be “recovery” and not a “workout” you need to keep your HR under 120 bpm for 15-30 minutes, otherwise you are stressing the cardiovascular system too much and not allowing it to recover.
One last thing to note – you don’t need a super fancy and expensive HR monitor to take advantage of these things. All you need is for the thing to tell you what your HR is at the moment and the least expensive Polar monitors (the brand I use and recommend) do a fine job of that without all the bells and whistles that drive the price up and usually just confuse the user.
So there you have it, 3 way to use your HR monitor that will actually result in improved cardio for mountain biking. Riding faster and longer on trails requires the ability to push hard, recover and then do it again and again and using your HR monitor in theses ways will help you do just that.