Heart Rate training. What is it? This is one of the ultimate decisions a runner may make when starting a training plan or training cycle.
There are two basic methods of training for runners who track their data, training by heart rate and training by pace. The heart rate training method uses biofeedback to determine effort and the runner trains accordingly.
As a result, runners using this method completely ignore pace. By ignoring pace and going by heart rate, they will be running by a set effort. This offers the ability to train at a set effort level consistently, but the results will fluctuate based on how a runner feels that day. It helps take in consideration factors like lack of sleep, diet, weather conditions, stress and more. So a runner who gets a full night sleep and is feeling well may run a pace of 8 minutes per mile on a run. The next day, they may be short on sleep, and it is warm out. They may run an average of 8:20 minutes per mile at the exact same heart rate.
On the surface, this seems to be a simple principle, but application is fragmented. At a basic level, runners will train using their heart rate as a guide. They will determine a range of beats per minute is a guide during a workout or sections of a workout. These are often called zones.
When looking at the heart rate structure, there are two overall categories – Aerobic and Anaerobic. Aerobic exercise means that there is enough oxygen for the muscles to clear lactic acid and the body is able to perform at the rate for extended periods of time. Aerobic training also increases both mitochondria and capillary density over time — the wider the path, the fewer beats needed for the heart to drive the system. This increased efficiency of the heart is shown in studies including Effects of low intensity aerobic training on skeletal muscle capillary and blood lipoprotein profiles. The article Mitochondria: The Aerobic Engines by Kirk Willett adds more information about the role of mitochondria in aerobic fitness. Aerobic exercise also uses fat as its primary fuel. This is important because the body typically has fat stores that can sustain hours of activity. More intense exercise burn up glycogen stores in the liver. These stores are limited and when depleted, the athlete will suffer a condition known as “bonking” if they have been unable to consume nutrition. There is a limit to the nutrition a body can handle during exercise making bonking inevitable over a extended period of time. If an athlete is able to run within an aerobic zone, the fat will sustain them.
Anaerobic exercise is the equivalent of an overdrive. It is used in short intense efforts. This training is used for developing running form and speed. It is often neglected by distance runners, but critical for development as explained by Steve Magness in HS training: Neuromuscular and speed work and Matt Fitzgerald in Anaerobic Development Is Key To Running Speed.
Aerobic and anaerobic training are typically separated by the Lactate or Anaerobic Threshold.
At the highest level, lactate or lactic acid is a chemical generated in the muscles during bouts of strenuous exercise. The body is naturally able to clear this chemical at lower levels of intensity. But as the intensity increases, the chemical begins to build up and athletes feel a burning sensation and their limbs feel stressed. There is a detailed explanation of why the buildup occurs in Scientific American – Why does lactic acid build up in muscles? And why does it cause soreness?
The highest point that the body is able to clear lactate without accumulation is known as the Lactate Threshold. This threshold is determined via a blood test where an athlete continues to have blood taken (typically a pin prick) while steadily increasing effort in exercise. A close proximity can also be achieved via a field test. One of the most highly regarded was created by Joe Friel found on his blog in Determining your LTHR.
Once the lactate threshold is determined, a runner can use it combined with the maximum heart rate and resting heart rate to determine heart rate zones.
This opens another can of worms. What are zones? Let’s start with an overall definition that most can probably agree with — “A heart rate training zone is a range that defines the upper and lower limits of training intensities” — from the article Heart Rate Training Zone on medicine net.com. An athlete’s heart rate training range is broken into multiple zones derived a combination of some or all of the following data points: their age, max heart rate, resting heart rate, lactate threshold, 220, or 180.
The confusion comes from the different formulas and factors. One of these is the maximum heart rate. This can be derived by different formulas that are shown in this article on Digifit – Calculate Your Maximum Heart Rate. This article can be used to demonstrate why formulas are not always helpful. My age is 43 for example and that gives me a maximum heart rate of 168-188. That is a 20 beat disparity alone, but it gets worse when I consider my actual max heart rate determined by races – 200. So, we are looking at a 32 beat range. That in of itself is multiple zones.
This is where lactate threshold can be useful. It can be used as the line between aerobic and anaerobic training. The only thing left is to determine the zones.
Most heart rate training plans break up training into 4-5 Zones as follows:
Zone 1: Recovery Zone. Very easy pace.
Zone 2: Base Building Zone. This zone is a moderate effort zone and is used to build endurance. Athletes can stay in this zone for extended periods of time.
Zone 3: Tempo. Marathon pace zone. Sometimes called the gray zone – more to follow.
Zone 4: First Anaerobic Zone. This is above the lactate threshold and is used to train the body to start burning handling lactate build-up. This is where threshold runs are typically run.
Zone 5: This is the highest zone. It is sometimes broken into parts itself (by Joe Friel for one). Speed work is performed in this zone.
Note: Zones 4 and 5 are sometimes combined into a single zone for a 4 Zone model.
One place to look for setting the actual zones is Joe Friel’s Quick Guide to Setting Zones. Some combine zones 5a – 5c into 5 figuring everything above 100% is 5.
Earlier that I mentioned that Zone 3 is sometimes called the gray zone. There are many coaches who feel that it is a bad zone to train in because it is too hard for active recovery and too easy for physical or neuromuscular adaptation. Joe Friel refers to it as “Happy Hard.”
So is it a bad place to train? It depends. As Joe Friel writes in the post Should You Train in Zone 3? he explains that it is an effective zone for races that are longer than 2 hours and shorter than 6-7. This falls right in the marathon range (and possibly half depending on race pace) and may be where some of the confusion lies. If someone is training for a shorter race, they will likely need to be spending more time either running hard at zone 4 and higher for speed work, or easier for recovery and base building endurance.
By the same token, someone running a longer event like an Ultramarathon or Ironman triathlon event will likely be hurting themselves because they will need to sustain zone 2 throughout their race, or work on physical adaptations with zones 4 and higher.
Zone 3 is really the realm of the marathon runner and many argue that is where famed coach Renato Canova trains his Kenyan runners much of the time. The idea is to keep them just under their lactate threshold for as long as possible. It has also been speculated that zone 3 is the level of effort that is represented by “Steady State” credited to legendary coach Arthur Lydiard.
To add more to the confusion, there is the popular training method devised by Dr. Phil Maffetone, who worked with Ironman legend Mark Allen. The Maffetone Method is basically 180 bpm – age +/- 5 beats depending on the athlete’s experience and injury history. A variance is also added for older athletes of up to 10 bpm depending on their fitness. The result of the formula is known as the Maximum Aerobic Function (MAF). Athletes are to train in the range of their MAF-10 to their MAF. For example, my MAF would be 137 (180-43) and my training range would be 127-137.
Over time, most athletes will improve and run at a greater pace within their MAF zone. This is determined by performing a MAF test periodically. This method is especially effective for ultra marathon, Ironman, and athletes recovering from injury.
The above is a small view into heart rate training. It actually only scratches the surface, but hopefully gives a general idea of what it is about. Another type of training that can be tied to heart rate training is perceived effort. I will be covering that in a follow up piece about pace-based training.
In the meantime, if you want to hear an excellent podcast that gives a good view of how to use heart-rate training, please check out Endurance Planet’s ATC: Lucho’s Guide To Heart Rate Training, Improve VO2max in 7 Sessions, Causes and Remedies for Groin Pain, Common First-Timer Ironman Mistakes, Mighty Mitochondria, and More (Not a pithy title, but an excellent show).
Heart rate training is what you make of it. It is a tool. And like many tools, there are different methods to its use. Not all of them are alike and most of them are effective. It is up to the athlete to decide what is the most effective.
Heart Rate Training Tools
If you are interested in Heart Rate training, you will need to have a method of obtaining data. This can be done very inexpensively with a basic heart rate watch like the following:
NOTE: The above link is an affiliate link and I will receive a small commission at no additional cost to you.
If you have a modern smartphone like iPhone or Android that supports Bluetooth LE, you can get a strap to use in one of the many applications that track running like Runkeeper, Runtastic, MapMyRun, or Strava to name a few. This is a pretty widely compatible heart rate strap, but always check the application you are using to be certain:
If you want to track heart rate and collect pace statistics as well, this is a great entry level choice:
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