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The Infamous Hormone Cortisol: Is it really a weight loss inhibitor?

Today we are going to break down the infamous weight loss inhibitor: Cortisol. Cortisol tends to get a bad rap in the health and fitness world. But is it's stigma justifiable? Let's break it down to understand it's role in a weight loss or resistance training routine. First off.... what is it? Cortisol is a catabolic/signal hormone, meaning that it is responsible for breaking down protein and other substrates when glycogen stores are low. Additionally, it suppresses many glucose-dependent processes like immune cell function and glycogenesis (storage of glucose as glycogen in your muscle cells). A good example of cortisol’s role in your body can be evidenced by the muscle atrophy following an injury. If you fracture your tibia and immobilize your leg via a cast or crutches, cortisol mediates a nitrogen wasting effect in order to generate energy for the healing process. Cortisol utilizes the contractile protein of the injured area, resulting in muscle atrophy and the loss of strength. What role do hormones (like cortisol) play in resistance training? Hormones are secreted before, during, and after exercise. Acute hormonal secretions send info to the body about the amount and type of physiological stress of the resistance exercise (via epinephrine), the metabolic demands of the exercise (via insulin) and the possible need for change in resting metabolism. The stress of resistance training: 1) alters the ability to import nutrients and the sensitivity of the hormone receptors in the muscle cells and 2) stimulates local inflammatory process and activates repair mechanisms to initiate recovery. This leads to alterations in muscle growth and strength. While cortisol is often painted in a negative light, it does play an important role in muscle hypertrophy and strength gain. ACUTE increases in cortisol are actually good. When cortisol is released from heavy resistance training, it stimulates growth hormone and promotes the remodeling of tissues. This means that the acute release of cortisol is ESSENTIAL to RECOVERY. However, if cortisol levels are chronically elevated, it can produce hazardous effects towards your training, health, and weight loss journey. What are the consequences of elevated cortisol levels? In regards to resistance training, the most noticeable signs of elevated cortisol include a decline in force production and muscular strength. Elevated Cortisol is a clear indicator of overtraining and the potential for injury. Another consequence of elevated cortisol is evidenced through a compromised immune function. Cortisol suppresses B and T cells, hindering recovery and weakening the immune response. Possible consequences could include everything from joint and muscle pain, to fatigue, low energy, injury or loss of strength. Because cortisol inhibits protein synthesis by utilizing contractile proteins for energy, it holds the potential to wreak havoc on your weight loss journey. If your body is in a chronically stressed out state, it will pull from the available amino acid supply for energy instead of metabolizing fat. Not only will this prevent you from losing weight, but will make recovery from exercise quite difficult. How can hormonal imbalance with cortisol be prevented? As we previously mentioned, exercise is a STRESSOR. Thus, the key to minimizing hormonal dysfunction and elevated cortisol levels is to keep external stress low. Life happens, I get it. There are things that are way out of our control, and other things that are in fact within reach. Getting proper sleep, eating well, planning ahead, meal prepping, and staying on top of mobility and stretching are just a few ways to start! In regards to training, a periodized programming with complete days off from the gym and a decrease in volume and intensity will prevent elevated cortisol levels due to overtraining. If you have questions about what constitutes a deload, when to deload, or other questions about cortisol, feel free to reach out! I hope this article gives you a basic overview of cortisol’s role in your health and fitness journey. Remember: cortisol is not inherently bad; just a signifier that your body is stressed and needs rest. Until next time,



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