Exercise Physiology 201: Speaking the Same Language

In my last article on ‘Exercise Physiology 101: The Basics’, I outlined some of the key critical transitions that occur within the body when faced with an increasing exercise demand. In the name of practical applicability, coaches have used various methods to approximate these critical points and a variety of terms to describe the range that encompasses the transitions between these points.

The mixed use of terms like Zone 2, Compensation Training, Maximal Aerobic Function Training, Reps, Intervals, ½ Paced Efforts, Tempo Training etc etc. can leave 2 intelligent coaches speaking 2 totally separate languages, the equivalent of Swahili and Japanese, if you will. To make things worse, the Swahili definition of ‘Tempo’ is completely different from the Japanese definition, so even those words that are common to both languages or systems can have definitions that are completely distinct and different. No wonder athletes get confused!!

In this article, I will present our own Endurance Corner terminology and will outline how it relates to the concepts outlined in the last exercise physiology article and also to the many and varied terms used by some of the more popular coaching systems.

Let’s begin by defining the terms that you’re likely to hear at Endurance Corner:

Easy Training (AeT-10 to AeT) – Improves your ability to generate energy from fat (especially for Novice athletes), enhances mitochondrial proliferation and capillary density (although less so than steady training). For the advanced athlete, enhances recovery between sessions.

Steady Training (AeT to AeT+10) – Improves your ability to generate energy from fat (intermediate athlete), enhances mitochondrial proliferation and capillary density in FOG fibers (these points are VERY important for aerobic energy production at all aerobic intensities above this zone), creates biomechanical adaptations that allow training at more intense levels. Training above this level places increasing risks for overuse injuries, especially in the novice athlete.

Moderately-Hard Training (AeT+10 to VT1/LT) – Improves the ability of your FOG fibers to produce energy from fat, enabling you to include more intense main sets in your longer races and your basic week.

Hard/Threshold Training (VT1/LT to OBLA/FT) – Develop the ability of your fast twitch fibers to produce energy aerobically. At the upper reaches, this intensity also enhances cardiac stroke volume and VO2max.

Very Hard/VO2max Training (OBLA/FT to Max)– Maximally develops the ability of your cardiovascular system to deliver oxygen to your working muscles.

Now, comparing our definitions with some of the more well-known systems we come up with the following table:

We offer this table as an approximation of the way that the various definitions ‘fit together’ so that we may almost speak the same language as athletes who use other systems. I say almost because, rather than being based on independent physiological markers such as aerobic threshold, VT1 etc, the bulk of systems are based on somewhat arbitrary percentages of one point, e.g. Max heart rate, threshold heart rate or functional threshold power. In these cases, the computations will not always line up with the physiological markers. For this reason, I am a big advocate of defining each point separately via lactate, VO2/VCO2 or, when lab testing is unavailable, simple breath markers.

Train Smart.

AC.