Expanding upon our previous conversation about resting heart rate, let’s delve into the myriad positive transformations that occur within our bodies as a result of effective training.
The concept known as the “training effect” encompasses a series of physiological changes triggered by our exertion. Initially used to describe the favorable adaptations brought about by exercise, the term “training effect” has now evolved into a metric that gauges the degree of improvement across various indicators. For the purposes of this discussion, we will stick to the traditional usage of the term.
In our previous article on resting heart rate, we explored certain physical alterations that take place within our hearts, such as changes in chamber size and enhanced contractility. However, there are additional transformations that transpire to enable our hearts to function more efficiently when subjected to exertion.
The heart muscle relies on the coronary arteries for its blood supply. Effective training induces a dilation of these arteries, allowing for an increased flow of blood to reach the heart muscle. This aspect is crucially important and can be better understood by examining how blood supply is distributed to the heart muscle, as well as to all muscles in general.
During a heartbeat, as the heart contracts and pumps blood from the left ventricle into the aorta through the aortic valve, the surge of blood causes the aorta to stretch, accommodating the additional volume of fluid. Subsequently, once the heart has finished expelling blood and begins to relax, the pressurized blood in the aorta naturally seeks the area of lowest pressure, which happens to be the empty and relaxed ventricle. At this point, the aortic valve closes, preventing the blood from flowing back into the heart. Remarkably, situated just outside the heart on the other side of the aortic valve are the origins of the coronary arteries, known as the “ostia.” Consequently, when the blood rushes back towards the heart and the aortic valve shuts, a portion of the blood is redirected into the coronary arteries. The miracle persists as this blood rushes into the heart muscle while it is in a relaxed state. It is worth noting that blood flow into any muscle is significantly impeded when the muscle is contracted, as the arteries and capillaries are compressed tightly during such exertion.
Therefore, blood nourishes our heart muscle in the intervals between heartbeats. This realization elucidates the rationale behind the existence of an upper limit, or “range,” for maximum heart rate, as excessively high rates do not allow sufficient time for blood to flow into a relaxed muscle. Consequently, the growth of the coronary arteries is a remarkable adaptation, enhancing their capacity to transport an ample supply of blood to meet the heart’s demands.
Exploring the realm of positive transformations induced by the “training effect,” we cannot overlook the significance of the changes that occur within our coronary arteries. Indeed, they play a vital role in this process.
The enhancements in blood flow are not limited to our coronary arteries alone; our other muscles also experience a notable upgrade. As our leg muscles fervently demand increased nourishment, the body responds by enlarging the arteries that serve them and cultivating a more extensive network of capillaries. The development of new capillaries, referred to as “angiogenesis,” takes place as a result. Interestingly, some prominent professional teams initiate their riders’ seasons with a regimen focused solely on high-cadence and low-resistance pedaling for several weeks, as it is believed to stimulate angiogenesis. It is important to remember that blood flow into muscles is constrained during forceful contractions. Therefore, engaging in light-resistance and high-cadence work during this training phase maximizes the blood flow. A notable example of this is spin-ups. This is precisely why coaches emphasize staying within Zone 3 during spin-ups, as this effort level avoids excessive muscle contraction and enables the leg muscles to optimize their blood flow. While they may not delve into the specifics, their coaching instructions hold good reason. Progressive Zone Endurance (PZE) rides are a fundamental part of this process.
Unsurprisingly, training also yields improvements in lung function. After all, an abundant blood flow accompanied by limited oxygen supply would not yield optimal results. As I elucidated in a previous post on breathing mechanics, the reminders we receive about maintaining proper posture on the bike are aimed at facilitating optimal breathing efficiency.
The training effect leads to a strengthening of our diaphragm, allowing it to draw fresh air into our lungs more effectively. Additionally, our lungs experience an increase in their ability to exchange oxygen and carbon dioxide, as the lining of our lungs becomes more permeable to gases. The “coefficient of diffusion” serves as a measure of the lungs’ capacity to exchange gases. Rest assured, there will be no quiz on this later!
In summary, the combined outcomes of improved heart function, enhanced lung function, and muscles boasting a denser capillary supply are the fruits of the training effect. I hope this explanation sheds light on a few aspects and underscores the substantial benefits of Progressive Zone (PZ) training.
Learn more about Peloton Power Zone training and Peloton FTP test how they will help you become a stronger athlete.
This article is part of an ongoing series on Power Zone Training. You can find the other entries below in suggested reading order:
#1 – What is Peloton Power Zone Training?
#2 – Peloton FTP Test Strategies & Lessons
#3 – Peloton Power Zone Training – My Zones Are Too Easy!
#4 – Living with new zones & more FTP test
#5 – Post Peloton FTP Test New Zone Struggles (Mental & Physical)
#6 – Decreases in Peloton FTP
#7 – Age-related limitation & degradation of FTP in Power Zone Training
#9 – Resting Heart Rate: Why Power Zone Training reduces it
#10 – The “Training Effect” (This article)
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