VO2max applies strictly to the highest oxygen consumption value attainable for the whole body. VO2peak on the other hand is contextual. For example, during small muscle mass exercise (like on arm ergometer) your highest attainable VO2 value is much lower than your VO2max. As a result, we would refer to this as a VO2peak. However, during whole body exercise VO2peak often equals VO2max.

The attainment of a true maximum VO2 value requires a certain percentage of total muscle mass be engaged. Interestingly, once a ‘critical mass’ of total muscle is used, the engagement of more muscle mass may not increase…


How do you if your training methods are effective? The simple answer is that you track performance over time, and if it’s improving, you know whatever you’re doing is working.

A more difficult question to answer is why your training methods are leading to the observed performance improvements. I’m always skeptical when I hear coaches talk about their mitochondrial biogenesis protocols, maximum lactate steady state progressions, and methods to increase stroke volume. It’s not that I don’t believe that these methods improve their athlete’s performance, but rather that I don’t buy the reasoning behind them.

There are plenty of protocols…


The Tug of War Between Metabolic Vasodilation and Sympathetic Vasoconstriction & It’s Implications

Blood flow regulation is one of the most interesting aspects of human physiology. When we perform high intensity exercise we utilize oxygen at a greater rate than it can be supplied to the skeletal muscle, and as a result there is a net deoxygenation of the skeletal muscle (Figure I).

Figure I — Oxygen utilization responds immediatley to load. Key: Green = SmO2 (muscle oxygen saturation), Blue = SaO2 (arterial oxygen saturation), Red = THb (total hemoglobin)

In response to this hypoxia in the skeletal muscle we experience ‘metabolic vasodilation’ which is a process by which we increase blood flow. This process is relatively simple during single joint or small muscle mass exercise, like…


The Role of The Skeletal Muscle Pump In Maximal Endurance Performance

If an aeronautical engineer where to analyze a bumblebee they would quickly occlude that it could never fly. Yet, it does. Similarly, if a hydrodynamic analysis were done on the human circulatory system it would lead to the conclusion that human beings cannot stand upright, Yet, they do. We partly owe this ability to our ‘second heart’.

While the heart acts as the ‘master pump’ in our bodies, it could not function without a secondary pump, called the ‘muscle pump’. The muscle pump acts as a secondary heart on…


Assessing Skeletal Muscle Blood Flow Redistribution with NIRS

Blood flow regulation is one of the most interesting aspects of human physiology. When we perform high-intensity exercise, we utilize oxygen faster than it can be supplied to the skeletal muscle. As a result, there is net deoxygenation of the skeletal muscle. In response to this hypoxia in the skeletal muscle, we experience ‘metabolic vasodilation,’ which increases blood flow. This process is relatively simple during single joint or small muscle mass exercise, like a bicep curl. However, it becomes increasingly complex when we progress to regional exercise using multiple muscle groups close…


A Cheap & Non-Invasive Method for Identifying Metabolic Thresholds

As exercise load increases, muscle oxygen saturation in the working muscles will decrease. This is one of the first things you’ll observe when using a NIRS device, like a Moxy Monitor. As a result, it’s common to see ramp incremental exercise tests used to assess oxygen kinetics during exercise with NIRS.

For example, if you’re working with a rower you might put them on a concept 2 erg and have them row for 4:00 at 150 watts, then each subsequent 4:00 block you increase the power output by a fixed amount…


Identifying Changes in Muscle Coordination & Recruitment During Maximal Effort Exercise

The other day I had one of my rowers (lets call him Steve) do a 2k row for time at a fixed stroke rate (32–36 SPM). He rowed the 2k in 6:22, and in the picture above you can see the muscle oxygenation trends from his vastus lateralis and rectus femoris muscles. You’ll notice that the desaturation curves are quite different between these two heads of the quadricep, which may seem perplexing at first glance.

In order to understand why this is the case we need to appreciate the…


Can You Assess Muscle Fiber Composition With NIRS? If So, What Are The Implications?

In a paper titled, “Influence of muscle fibre composition on muscle oxygenation during maximal running” investigators sought to find the relationship between muscle oxygen saturation (SmO2) levels during maximal effort running and muscle fiber composition. Using a combination of NIRS and muscle biopsies from the vastus lateralis muscle, they found a significant correlation between minimum SmO2 during max effort running and muscle fiber composition. …


VO2max As The Maximum Integrated Capacity of The Pulmonary, Cardiovascular, & Muscular System

VO2max refers to the maximum rate of oxygen consumption measured during intense exercise, typically measured in ml of O2 per Kg per minute.

The concept that there exists a finite rate of oxygen transport from the environment to the mitochondria of exercising muscles began with Hill, Long, and Lupton. Since then, VO2max has become one of the most ubiquitous measurements in all of exercise science.

VO2max is calculated by Fick Equation, which states that VO2max = Q*[Ca-vO2] where Q stands for cardiac output (expressed as heart rate…


How Moxy Monitor is Revolutionizing High Performance Training

To kick off this article on applied bioenergetics and NIRS, i’d like to introduce you to the Moxy Muscle Oxygenation Monitor, which is a device designed to measure both total hemoglobin and muscle oxygen saturation levels in a muscle in live time using near infrared spectroscopy (NIRS). Near infrared light generated by the Moxy sensor travels from the emitter on the underbelly of the device through the skin to interact with the muscle, and then the light is scattered back to the detectors in the sensor.

The sensor takes the raw data…

Evan Peikon

Evan Peikon is an integrative physiologists with an interest in enhancing human performance. IG: @Evan_Peikon. Website: www.emergentperformancelab.net

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