Training 4 Life: 9 Adaptations: Long Duration Endurance

In the last article from the Training 4 Life series; I introduced the 9 adaptations that the body makes to exercise stimuli as characterized by exercise scientist Andy Galpin. The 9 “adaptations” our bodies make to exercise stimuli are:1. Skill Development, 2. Speed, 3. Power, 4. Strength, 5. Muscular Endurance, 6. Muscular Hypertrophy, 7. Anaerobic Capacity, 8. Aerobic Capacity, 9. Long-Duration Steady-State Endurance. Through the next several articles I will discuss these 9 concepts.

“Long-Duration Steady-State Endurance” is mentioned last on the list but is a good place to start for several reasons. Activities that improve our body’s long duration endurance are good for those just getting started on an exercise program as well as those who are exercising regularly wanting to improve their overall fitness. These activities tend to be low stress activities that have very positive physiological effects.

Activities that improve this kind of endurance are activities that you can do for a long period of time at a moderate pace continuously. For many people just getting started on their fitness journey, a brisk longer walk would be an example.

For the person who already exercises regularly, exercising at different intensities is a good idea. But even for those who are advanced in their fitness habits, longer bouts of moderate intensity workouts complement other training modalities such as high intensity interval training. Long moderate intensity “cardio” serves a foundation for building our fitness.

When we exercise at different intensities our bodies are stimulated to adapt in different ways. Part of why this happens has to do with how we use energy for movement. The blend of fuel sources we use changes with different exercise intensities. For an in-depth video on this subject check out this video: “Energy for Exercise, How We Make It: 55 Min Phys” by Andy Galpin .

When we engage in moderate paced long duration activities, we tend to use a higher proportion of fat to make energy. Getting energy from fat involves a process that occurs in our mitochondria (glucose and lactate can also be turned into energy in the mitochondria).

Diagram from earth-site.co.uk

Mitochondria are one of the most interesting and essential components of our body. They are often called “the powerhouses of our cells”. They are found within our cells and have many functions including taking stored energy and creating energy in a form that our bodies use. Each of our cells can contain hundreds or thousands of mitochondria.

The theory of how mitochondria came into being is fascinating. Mitochondria have their own DNA which is more than just super cool. It is actually a very useful fact. Check out this 10 minute video for an introduction to these concepts or this 8 minute video for a little more on the history of mitochondria and how they are kind of similar to chloroplast.

Mitochondria are not just incredibly fascinating but how well mitochondria function and how well our bodies are able to take advantage of mitochondria are very important factors in our overall health. For a deep dive into these concepts check out the journal article “The Key Role of Mitochondrial Function in Health and Disease”

While you can improve function and quantity of mitochondria with high intensity bouts of exercise – moderate intensity exercise may offer greater benefits. Long duration steady moderate intensity exercise is often referred to as “zone 2 training”. There are different ways of defining exercise intensities with some people using a 5 zone model, others a 6 zone model or even just a 3 zone model. In general, “zone 2 training” can be described as a training intensity where you are working hard enough to get your heart rate up, but you are not out of breath and could still talk to someone in short sentences while engaging in the exercise.

For an interesting 22 minute presentation on “zone 2 training” check out this video produced by the Institute of Human Anatomy. For a little more of the science from one of the leading researchers in the field, check out this video. In the 15 minute video Inigo San Millan, PhD breaks down how he thinks of the different training intensity zones (Inigo San Millan states he made an error at the 13:14 mark in the video – he meant zone 4 not zone 2). Inigo San Millan, PhD is a professor at the University of Colorado School of Medicine who also happens to have coached the winner of the 2020 Tour de France.

In later articles we will explore a little more of the science and a lot more of the practical aspects of “Long-Duration Steady-State Endurance” training. The next article in this series Training 4 Life will address another foundational aspect of health – resistance training.

What we eat is another key action we do that impacts our health and wellbeing. Click here for my article on protein nutrition: “Amino Acids, Not Just Building Blocks of Proteins”. Also check out another new article I have recently posted on “Exercise Planning and Programing: Inspiration, Motivation, Discipline, Habit, and Passion”.

Thanks for reading. Please share with others.

Russ