Stress & Cortisol
We experience stress everyday (such as finishing off an assignment or meeting work deadlines), generally when there is an imbalance between the demands being made on us and how we cope with those demands. Stress is your body’s defences kick into gear in a fast, automatic process known as the “fight-or-flight” reaction, or the stress response. In caveman times when you see a hungry lion, your body responds by sprinting away from the lion or you become the lion’s dinner.
When you’re stressed, your body produces a hormone called cortisol (commonly known as the “stress hormone”) and one of its major roles is to break down stored carbohydrate (in the form of glycogen) to blood sugar as an energy source. Cortisol provides the fast energy that your muscles need to escape from the hungry lion.
However, having chronically high cortisol can increase the production of a brain neurotransmitter (called neuropeptide Y) which increases your appetite – not good if you’re trying to lose weight. Cortisol is a catabolic hormone, meaning it can also breakdown muscle protein. The problem is exacerbated when you’re on low-carbohydrate diets. Losing muscle mass will decrease your metabolism.
To ensure you have healthy cortisol function, recognise when you need to take steps to reduce stress (try yoga or meditation or seek professional help). Exercise is good for your health but the physical stress of too much training can result in higher cortisol levels, so make sure you’re not over-training. For most people this will not be a problem.