1/4 Hour Neuro #63: "Physiological Profiling and Training Zones" - Sean Seale

Welcome to the Podcast

Welcome to this episode of the ¼ Hour Neuro, where we host Sean Seale. If you haven't met him yet, stay tuned, as he offers high-quality podcasts and very relevant training. This ¼ hour will be an opportunity to discover Sean, his journey in physical preparation, and his innovative vision.

Sean Seale, 33, splits his time between private coaching, remote monitoring, and physiological testing. He conducts exercise tests for endurance and CrossFit athletes, focusing on conditioning. He also hosts a podcast and a YouTube channel, and has recently launched online training programs.

The Modern Vision of Energy Pathways and Training Zones

Sean approaches energy pathways from a modern perspective, breaking away from outdated models. His training is highly theoretical and focuses on the concepts of physiological thresholds and training zones. He observes a great deal of confusion surrounding these concepts, due to the multiplicity of methods for quantifying thresholds (lactate levels, ventilation, etc.).

The goal of his training is to provide a synthesis of this information, so that coaches can interpret the first and second thresholds, understand the different definitions of zones (three, five, six, seven zones, polarized model), and have a framework for better utilization. It is essential to have a solid foundation and a common vocabulary regarding energy pathways, their functioning, interaction, and the central role of oxygen, both metabolically and in terms of cardiovascular and respiratory health.

Often, we talk about training a specific pathway, but forget about the respiratory and cardiovascular systems involved. Sean offers a theoretical framework to better interpret physiological thresholds and training zones.

Lactate: Beyond Metabolic Waste

Sean deconstructs myths surrounding lactic acid and lactate. While lactic acid has long been viewed as a mere waste product, new research highlights its much more complex role.

Lactate is indeed the final product of glycolysis, but it is an extremely interesting molecule. It is not a waste; rather, it is an energy substrate that the body can reuse, whether in the muscle fiber that produced it, in adjacent fibers, or after being transported in the bloodstream to be oxidized elsewhere (heart, brain, liver). Furthermore, lactate is an important signaling molecule, influencing fat oxidation. A recent article by Jack Brooks, "Lactate Phoenix Reborn", underscores its central role in the human body, emphasizing the need to properly contextualize it.

Lactate and oxygen are crucial for the brain. Depending on the transporters used, lactate can positively impact the brain, optimizing certain functions and emotional factors. This is particularly relevant for neuro-postural reprogramming and the body's energy optimization, where physical activity plays a fundamental role.

Physiological Profiling and Training Optimization

Individualization of Training Zones

The physiological profiling tests conducted by Sean aim to establish an accurate and individualized intensity distribution for each athlete. This allows for defining the appropriate training zones, based on current physiology, rather than on percentages of maximum heart rate, which can vary significantly between individuals.

By measuring physiological factors during a progressive test, training zones can be established that ensure an adequate intensity to generate the desired physiological responses and adaptations.

Determining Work Axes

These tests help to determine specific work axes based on the individual's profile. An athlete training for a 2000m rowing event will have different needs than an ultra-endurance cyclist. With data such as the first threshold, critical power, second threshold, or VO2max, it is possible to establish a profile and identify the factors that require the most work.

The assessment of the physiological systems involved in performance includes a respiratory evaluation (resting spirometry for lung capacity, ventilatory data during effort), cardiovascular (heart rate, recovery), and muscular (muscle oximetry with Moxy for the balance of oxygen supply/utilization). The athlete's training history is also crucial: knowing what they have done, what they like, and what they avoid often helps to understand their needs and weaknesses. The goal is to provide a comprehensive assessment to redirect training intensities individually and specifically address identified needs.

Addressing Weak Links

The speed of changes in weak links depends on the individual. The more trained an athlete is (elite level), the longer adaptations take (4, 6, 12 months or more), as they are already close to their maximum potential. For a beginner, changes can be more rapid (gains in VO2max in a few weeks, increases in critical power). Some metabolic and structural adaptations (capillary density, mitochondrial density) take longer. Not all elements evolve at the same speed, but rapid progress is possible if the work is tailored.

Rest and Effort Tests

The spirometry test is conducted at rest to assess respiratory capacity. For the rest, it is necessary to observe the interaction of physiological systems during effort. Research on mitochondrial function through reactive hyperemia tests (with a tourniquet and the Moxy tool) is promising. These tests, which measure local oxygen consumption and supply, could allow for quantifying mitochondrial function at rest, in addition to exercise tests. Observing the athlete in a competitive situation remains essential for evaluating their performance.

Respiratory Training: Benefits and Applications

Sean has tested respiratory resistance training with various tools, observing concrete improvements on the ground.

Impact on Effort Perception and Economy

A significant improvement in the perception of breathing has been noted. As effort perception is closely related to breathing, better respiratory control reduces perceived difficulty. Training also allows for better awareness and respiratory mechanics. Although there is no absolute "bad" breathing, some techniques are more conducive to performance. Running economy, in particular, improves, with a stronger and more enduring diaphragm better supporting spinal stabilization.

CrossFit athletes, who struggled to maintain their heart rate in their target zone during running, observed a reduction of 5 to 10 beats per minute for a given speed after a few weeks of respiratory training. This is considerable, especially since this work is neither time-consuming nor excessively difficult.

Initial Fatigue and Adaptation

It is common to experience significant fatigue after the first sessions of respiratory training, as isolated use of the diaphragm and other respiratory muscles is not familiar to many. This allows for focusing on these muscles and obtaining interesting effects.

Maintaining Respiratory Volumes

Respiratory training improves the ability to maintain larger respiratory volumes during sustained effort, whether in CrossFit, cycling, or running. This capacity can be specifically trained with dedicated tools, with a transfer to dynamic effort. Research shows performance gains of a few percent, which can be significant for some athletes. However, like any training, individual responses vary; it is not a miracle solution.

Practical Applications: Warm-Up and Recovery

Respiratory training is an interesting complementary modality, useful for maintaining endurance and intensity of the respiratory system, even during periods of low intensity or injury. Sean personally uses it as a warm-up before repeated sprints: a few minutes of targeted breathing exercises focusing on volume then frequency, prepare him for intense effort without excessively tiring on the bike. There are also interesting recovery aspects to explore. Information is still limited, but the prospects are promising for motivated individuals.