Finding information about heart rate training for distance runners is incredibly challenging. No doubt prior to arriving at this page you found yourself knee deep in articles about physiology that would confuse most anyone. Well we will try our hardest to straighten out confusion about using heart rate monitors while running.
When attempting to train based on heart rate, the first thing that must be discovered is your Maximum Heart Rate, because this is the base from which the rest of training is derived. There are two ways to determine max heart rate. The first is a simple calculation, [220 - Age = Max HR]. So if you are 40 years old, your max HR would be 180.
The problem with this method is that while it is quick, it is not always 100% accurate. If you are interested in finding a more accurate max HR, you can head to a nearby hill with a heart rate monitor to do a field test. Begin with a 15 minute warm up on flat ground. From there you will do 3 hill repeats. The first will be 2 minutes uphill at an effort that you could maintain for 20 minutes, then jog back down. The second repeat will be two minutes long at an effort you could maintain for 3 minutes. Note your heart rate at the top as that will be near your Max HR. Return to the bottom of the hill and let your HR drop 30-40 beats per minute. The final repeat is a 1 minute repeat all out. Note your heart rate at the end, that is your max heart rate.
Now that we know our max heart rate, we can use it while training. Greg McMillan, one of the premier distance running coaches in America, has extensively studied heart rate as it relates to training and has written about it on his website here. If you are interested in the nitty-gritty of heart rate and training, I recommend visiting his site. Be forewarned: it is complicated. I will try to simplify it as much as possible.
Basically, there are four training zones. The first is the endurance zone. This is the zone at which distance runners spend most of their time. These are the long, easy miles we do day in and day out. In this zone, our heart rate will be 60-75% of our max HR. So if our Max HR is 200, the endurance zone is 120-150. The next zone is the stamina zone. This zone is when our effort begins increasing and our breathing picks; it encompasses marathon pace all the way down to 8k pace. In this zone, our heart rate is 83%-92%. These two zones are where heart rate training is most useful. That is because in the endurance zone, we are simply attempting to build a base.
Often, runners don't spend enough time in that endurance zone. They end up running too fast, too often and get hurt. By training based on heart rate, though, we are kept in check for those many miles that are supposed to be done at a slow pace. The same can be said for the stamina zone. This zone marks the threshold between aerobic training and anaerobic training. When completing runs in this zone, the goal is to NOT go so hard as to start racing (which can often happen). By understanding our HR, we ensure that we are running exactly the right pace in both the endurance zone and stamina zone.
The final two zones, speed zones and sprint zones are not ideal for using heart rate, because they are meant to be near all-out. When attempting to work out at these zones you should not be concerned with heart rate, but rather you should be focusing on working as hard as you can.
Using heart rate monitors can be a great tool when training. They help us determine the paces we are supposed to hit on most of our runs, which can prevent us from overtraining and can keep us running healthy and strong. Use them for both motivation and to guide training, but do not be so tied to heart rate monitors that they become a source of stress. Hopefully that straightened up some heart rate confusion. Happy Running!