Threshold Training

Threshold training is a workout methodology that uses zone training with five zones and two thresholds to individualize the physical activity. These two thresholds, the T1 and T2 are a little bit more scientific in nature, but they allow for 5 zones of training versus 3. This is a method that usually lends itself more to more serious training, but is still applied within the Heart Zones Move Solution. You can easily set the T1 and T2 thresholds within the App & individualize them to each student in your classroom.

When training using the Threshold methodology, you are going to use a chart like the one shown here, that explains the 5 different zones of intensity. Your Blink Armband only flashes 3 colors and is more geared towards the ZONING Method, but using the Big Board, students can still see real-time which of the five zones they are in.

From the Head Heart, Sally Edwards

When I first began serious training with a heart rate monitor, around 1982, I was one of the earliest adopters of a new genre of equipment for sports performance called heart rate monitors. At that time, few competitive athletes had a heart rate monitor, and if they did, even fewer knew what the numbers meant or how to use it to improve our fitness. At that time, over thirty years ago, there was no such thing as heart rate zones. There were no other wearables – just a powerful and incredible heart rate monitor.

Back then, there was little to no understanding of what to do with a heart rate monitor or how to create programs or applications to help people get healthier or, for those of us that are competitive, to help athletes reach the finishers’ podium. And now this first wearable, the heart rate monitor, is about to celebrate it’s fourth decade birthday, with hundreds of millions of users around the world using it as one of their smart health and fitness training tools.

As a matter of history, that first heart rate monitor that I acquired in the early 1980’s was hard-wired to a small box that I wore on my chest without a watch — the heart rate data was shown with a small display on the top. Several years later, I purchased my second heart rate monitor for $400, which was a lot of money for a personal training tool that I knew little about. It was one of the first wireless heart rate monitors, the Polar Vantage XL. My journey as an applied exercise physiologist specializing in personal training tools was then in its infancy. And that journey grew into my authoring the first book on training with a cardiac monitor in 1992 titled The Heart Rate Monitor Book. It became a best-seller.

That’s the genesis of heart rate training and why I created the world’s first heart rate training system and wrote the first book about it — because there was nothing available for any of us from fitness enthusiasts to athletes. I knew that applying exercise science to training paid off in prize money, trophies, sponsorship, credibility, and being on the podium. I have dedicated the last three decades to creating programs using personal training tools — power meters, metabolic carts, activity trackers, speed-and-distance monitors, and heart rate sensors. Each of these programs are designed to help children and adults lose weight, lower their stress, get fitter, and to help individuals perform at their best.


An anchor point is a value or position that you can connect to. One of the reasons to affix training intensities to an anchor point is to set your training zones by “anchoring” them on a physiological or mechanical indicator. Biomarkers, indicators of where physiological changes occur, are standard anchor points for setting training intensities, or zones. These physiological markers occur as exercise intensity increases and the body compensates for the harder work by recruiting more working muscles, increasing and changing breathing responses, making changes in thermal responses (releasing heat, sweating), and metabolizing different fuels (substrates). Each of these different ways of detecting and measuring markers can be associated with, or coupled to, a heart response — in this case, a heart rate number in beats per minute.

As in sailing, when you toss out an anchor without knowing how deep the water is, you sure better have a lot of rope. Is the water depth 10 feet or 1 mile? Do you need 10 feet of rope or 5,280 feet of rope to attach to your anchor to secure your boat? Similarly, in training, if you don’t know your primary anchor numbers, your training might freely float with nothing to secure it to and nothing to use to make modifications to it.

anchor points depends on a different measurement tools and typically uses some complimentary analysis of the data that is collected. Once you have measured or estimated your anchor number and you have programmed that number into a heart rate monitor or other body or equipment worn sensor, then you know with every stroke or step your zones and other robust information like training load and training stress.

Those four key biomarkers are:

Lactate Threshold: Lactic acid concentrations in millimoles of blood lactate. Lactic acid is one of the products of anaerobic carbohydrate metabolism in the cells.

Ventilatory Threshold: Ventilatory changes with changes in the ratio of oxygen to carbon dioxide to total inspired and expired air.

VO2 Max: Maximum oxygen consumption or milliliters of oxygen con- sumed. Maximum oxygen consumption is the highest volume of oxygen (VO2) recorded during maximal exercise.

Maximum heart rate: The highest number of beats per minute that you can produce with genetic limitations.

Of these four markers above, which is the best physiological marker for you to use for anchoring your personal zones and training methodology? And how do you accurately measure that anchor point to set your different training intensity levels? The answer is: it depends.

It depends on your goals. It depends on your experiences. It depends on how much you know about training and how much you want to know about training. It depends on what personal or professional training tools you have or are willing to invest in. It depends on whether your objective is to get and stay fit or whether you are going for the gold. It depends on what equipment and facilities you have access to. It depends on which anchor point resonates with your style of training. And, maybe

most of all, it depends on what training methodology you believe in. Scientifically-based cardiovascular training systems or methodologies

Deciding on which training methodology, which heart rate monitor, and which anchor point for train-ing zones to use is a decision for you to make or for you and a certified coach to suggest. Before you decide on the training methodology that resonates with you, let’s go through each of the biomarkers so that you can choose one that best fits you.

The Two Thresholds – High (T2) and Low (T1)

There are two distinct ventilatory and lactate thresholds, the first and the second. Low ventilatory threshold, the first one, occurs at that cardio-intensity when there is first shift in the breathing pattern and acoustics. The most accurate way to assess each of the two ventilatory thresholds is to use a metabolic cart which measures inspired and expired air, aka ventilation.

This is a bit scientific but I still feel it important for you to undersant. The low or first threshold, T1, is marked by an increase in both the volume of oxygen consumed (VO2) and total inspired and expired air (VE, or ventilatory equivalent) while the amount of carbon dioxide expired remains constant. A second threshold, T2 occurs when the amount of air that we breathe shifts again, but this time there is an increase in carbon dioxide expired. This second threshold is called the high or second ventilatory threshold. There is no corresponding increase in oxygen consumed at the second threshold. This second shift becomes the marker for high threshold or T2. These two shifts in ventilation, T1 and T2 , are used as convenient biomarkers for anchoring the Threshold Training System zones as well as the ZONING fitness zones as well as assessing changes in fitness.

For our purposes and the majority of exercise scientist, the out-of-fashion term “anaerobic threshold” is now simply called “high threshold or T2”. It is a cross-over point between sustainable and non-sustainable exercise intensity. Whether measured using heart rate, power output, ventilation, lactate levels, or percentage of maximum oxygen consumption, the low threshold is the maximum lactate steady state, before lactate begins to rise. There is a great deal of controversy that surrounds the term “anaerobic threshold” (AT) by coaches and athletes hence another reason to discontinue using the term.


In the early 1980s, researchers began to first publish studies reporting that indeed there are two thresholds, not one. These two thresholds have now been accepted by most scientists and are just being popularized today.

The first or low threshold called T1:

Maximal lactate steady state = LT1 = range between 2.0–2.5 mM of lactate = sometimes confusingly called the aerobic threshold = VT1 = approximately 80% of maximum heart rate or simply T1

The second or high threshold called T2:

Approximately 4.0 mM of blood lactate concentration = sometimes confusingly call the anaerobic threshold = respiratory compensation threshold = approximately 85% VO2 max = individual anaerobic threshold = VT2 = about 90% of maximum heart rate or simply T2.

Generally, exercise scientists don’t care about how thresholds are measured, but that they are measured, period. And, for applied exercise specialists, field testing the two heart rate numbers as low T1 threshold and high T2 threshold are required to set the “Top of the Green” zone for T1 and the Top of the Orange Zone for T2.