Refocusing on Health: Building Muscle, Mastering Zones, and Metabolic Balance in the New Year
“First tell yourself what kind of person you want to be, then do what you have to do. For in nearly every pursuit, we see this to be the case. Those in athletic pursuit first choose the sport they want to, and then do that work.” Epictetus
As the festive season concludes and we enter the new year, many of us face the challenge of re-engaging with our normal routines or turning over a new leaf. We still carry the guilt of that last mince pie or overindulging over the holidays. It’s time to shed that guilt and worry that we cannot change and think about what we can implement to start initiating change for the better. This period of reinitiation offers a unique opportunity to refocus on long-term health goals rather than immediate performance metrics.
This provides a segway into reinforcing the importance of prescribed exercise and what benefits we gain from the different types of exercises we have encouraged you to take up. This article therefore concentrates on recapping the benefits of some of the foundations of training for great cardiometabolic health. Building Muscle, Zone 2 and Zone 5.
Building muscle is integral, not just for physical strength, but for overall health, metabolic function, and warding off frailty. Muscles act as an endocrine organ, releasing myokines (proteins released by muscle cells during contraction) which influence the function of organs and tissues throughout the body. This endocrine role is crucial for regulating inflammation and metabolism. Increased muscle mass is also linked to higher levels of testosterone in the body and can be stimulated by resistance training. As muscle mass grows, it can contribute to a more anabolic (muscle-building) environment in the body, potentially increasing natural testosterone levels.
Resistance training is essential to increase mitochondrial density, crucial for energy production and efficiency, showcasing the intricate cellular mechanisms at play in muscle development. Mitochondria are the energy-producing organelles in cells, often described as the "powerhouses" of the cell. This significantly contributes to glucose regulation in the body. Approximately 70-80% of the body's glucose is stored in muscle. It acts as a major site for glucose disposal, using glucose for energy, especially during exercise. Increased muscle mass enhances this capacity, allowing more efficient glucose usage and storage. This is particularly important in managing blood sugar levels and reducing the risk of conditions like insulin resistance and type 2 diabetes. Essentially, the more muscle you have, the better your body can handle and store glucose, making it an essential factor in metabolic health.
The concept of Zone 2 training, a moderate-intensity exercise characterised by controlled fat oxidation and lactate levels, is increasingly recognised for its comprehensive health benefits. By operating at a level where one can comfortably converse – estimated at about 60-70% of maximum heart rate - Zone 2 training enhances metabolic efficiency and endurance.
As you have found, to accurately identify your Zone 2 threshold, lactate testing or CPET can be employed. These methods provide a personalised and scientific basis for your training, ensuring that you're exercising at an intensity that maximises physiological benefits.
Zone 2 training at a cellular level primarily enhances mitochondrial density and function, crucial for efficient energy production. This increased mitochondrial efficiency leads to improved fat oxidation, boosting endurance as well as helping regulate blood sugar levels. Additionally, Zone 2 exercise promotes angiogenesis, creating new blood vessels that improve oxygen and nutrient transport to muscles. These adaptations contribute to heightened aerobic capacity and greater physical stamina, underpinning long-term health and performance benefits.
Re-starting Zone 2 in your routine is particularly beneficial after a period of reduced activity, such as the festive season. This approach helps in rebuilding aerobic capacity without the risk of overexertion. It's a method that aligns with our body's natural rhythms and capabilities, making it sustainable and effective for long-term health maintenance.
Zone 5 incorporates brief, high-intensity exercise bouts, interspersed with short recovery periods. The benefits of Zone 5 lies not just in its time efficiency but also in its diverse range of physiological benefits. One of the primary benefits of Zone 5 is its impact on cardiovascular health. It significantly improves parameters such as VO2 max, enhancing aerobic capacity and overall cardiovascular function. This improvement in aerobic capacity is indicative of greater cardiac output and oxygen utilisation during exercise.
Zone 5 also packs a metabolic punch, increasing post-exercise oxygen consumption, thereby facilitating greater calorie burn long after the workout is over. This increased metabolic rate is attributed to mitochondrial biogenesis, leading to improved efficiency and size of mitochondria in muscle cells during the recovery phase. They are particularly relevant in the context of Zone 5 as they are responsible for producing adenosine triphosphate (ATP), the cellular currency for energy. Zone 5 promotes the formation of new mitochondria, thereby enhancing the cell's capability to produce energy more efficiently. Improvement in insulin sensitivity is another advantage of Zone 5. This is particularly beneficial for individuals at risk of type 2 diabetes or those seeking better glucose control. At the cellular level, Zone 5 induces the migration of glucose transporter type 4 (GLUT4) to the muscle cell surface, thereby enhancing glucose uptake and improving glycaemic control.
Zone 5 is not just about cardiovascular endurance; it also aids in preserving muscle mass and increasing strength. This preservation and growth occur through the activation of the mTOR signalling pathway, crucial for healthspan and delaying frailty. This pathway regulates protein synthesis, thereby promoting muscle growth and preventing muscle protein degradation.
Muscle building increases size and volume, acting as an endocrine organ and regulating metabolism. Zone 2 training, at moderate intensity, improves mitochondrial density and function, aiding in efficient energy production and fat oxidation. Zone 5's high-intensity bouts enhance cardiovascular health, metabolic rate, and insulin sensitivity. Together, they offer a comprehensive approach to improving healthspan, aerobic capacity, and glucose control, essential for long-term health and vitality. As we navigate our return to fitness post-holidays, it's essential to embrace a balanced, informed approach. Prescribed training offers just that - a scientifically backed, health-centric way to rebuild and enhance our physical capabilities. It's a reminder that in the journey of health and fitness, steady and informed progress trumps short-term gains, setting the foundation for a healthier, more vibrant life ahead.
Written by Dr Andrew Crockett
