One major thing that you need to understand when it comes to stress is that there is eustress and distress; eustress being a healthy and beneficial stress while distress is an undesirable stress to be dealing with. Stress can influence everything from diseases to fat storage to mental breakdowns. For the purposes of this writeup, I am going to discuss how stress relates to exercise. To begin, lets get into the title of the book and what it basically means. It really does give a great overview of stress and how it relates to humans in society today from a generalized viewpoint.
Reading the title, Why Zebras Don't Get Ulcers, ask yourself the question. Why is it that zebras don't get ulcers? Our nervous system can be broken up into the Central Nervous System (CNS) and the Peripheral Nervous System (PNS). The PNS can be divided into the somatic and autonomic nervous system. The ANS can be divided into the sympathetic and the parasympathetic nervous system. These are the components that function unconsciously. The sympathetic is usually understood by the phrase “Fight or Flight.” It is activated during periods of arousal and physical stress. The parasympathetic nervous system is usually understood by the phrase “Rest and Digest.” It is active during periods of relaxation and rest, or during most periods of an average animal's day (normally, though we will soon see that this is not always the case today).
If you look at an animal like the zebra, the only real stressful situation that it needs to worry about is getting chased by a lion or some other predator. When it gets chased by a lion, its sympathetic nervous system is going full force and there are various physiologic changes that occur, including the release of specific hormones, one of these major groups of hormones called glucocorticoids. Basically, the body sets itself up to efficiently and effectively fuel muscular activity so that the zebra can sprint away from that lion and stay alive so that it can go graze in its field again. The key thing to realize here is that while there is a sympathetic stress response that occurs, the zebra uses up all of the hormones and substrates that are released and things inside the body return to normal; and parasympathetic state comes back shortly after. With humans today, there are an unlimited number of occurrences that can stimulate the fight or flight response. Relationships, work problems, traffic jams, bills, annoying people that make you wanna break things, exams, essay deadlines, processed foods and the list goes on. There are tons of things that release these hormones, increase heart rates, stimulate specific brain centers, etc. and they can do this multiple times a day, every day. It is generally a stressful society that we live in today. Zebras don't have to worry about these kinds of things. The problem with this is the following. When these things happen in the body as a response to stress, most people are usually not sprinting away from a lion and therefore do not use up the “fuel” that the body produces. Glucocorticoids build up, blood pressure gradually adapts and rises, fat storage increases, atherosclerosis develops, diabetes comes about, ulcers form, anxiety develops, brain cells are worn out and the list goes on. This brings me to my main point of this article.
It is an ABSOLUTE MUST to get in a decent amount of effective exercise in order to combat these effects. Strenuous enough exercise can use up the “fuel” that is produced with the fight or flight response and help return the body to its normal resting state. Exercise also creates a good stress to the body that will help it adapt and get stronger and better. The trick involves a couple of important points to consider. The exercise must be strenuous enough to both relieve the effects of the bad stress and generate enough good stress without going overboard and causing more bad stress. Overtraining needs to be avoided as this can add fuel to the bad stress fire that is already burning for many people. This means that doing a few curls with 2lb dumbbells or using a shake weight at Planet Fitness is not going to be anywhere near strenuous enough for most people. It also means that doing max effort squats and deadlifts before running balls out sprints 5 days a week, every week is going to be far too much for the body to adapt to and recover from effectively.
People who experience a lot of daily stress and do not perform any physical activity will enter a viscous cycle that will bring about detrimental effects both mentally and physically. So give your body some healthy stress through exercise and save yourself a lot of trouble while making yourself healthier mentally and physically. As an added bonus, if you ever do find yourself getting chased by a lion, you'll be much more prepared to get away safely.