Teaching you the essentials of fitness and weight loss

So what happens to my body when…

We all know that exercise is good for us but do we actually know what happens to our bodies when we do an endurance event such as a long swim or a long run for example? When we’re dehydrated, when we’re overtraining, when we severely limit our calories etc. If you’ve ever wanted to know the answer to the question, “what happens to my body when…?” then take a look below.


What happens to my body when I do a running or cycling endurance event


Research has shown that the mere anticipation of exercise increases blood flow to the soon-to-be working muscles, as well as oxygen consumption and the release of hormones, including epinephrine (adrenaline), that prime the muscles for activity. If you’re running or cycling, within the first 10 to 20 percent of a race, the core temperature rises relatively quickly, then for the remainder of the event it stays within a very narrow range—maybe 0.1 and 0.2 degrees Celsius. Triathlons and marathons can elevate C-Reactive Protein (the primary marker for full body inflammation) by well over 250%. Once you start to run out of carbohydrate stores, you body will start to turn to your fat stores and eventually start to breakdown your muscles for energy. Research has also found that after a marathon, immediately after the race there is a small, generally temporary drop in the efficiency of the right ventricle, the chamber of the heart that pumps blood to the lungs. This dysfunction fully recovered after one week for most athletes. All of the athletes included in the study trained for 10 hours a week or more though so this may not be reflective of the average population.


What about when I severely reduce my calorie intake?


According to the My Fitness Pal dietitian, if you regularly slash a reasonable number of calories (e.g., 250–500 calories per day) to lose weight, you may run into the dreaded weight-loss plateau after a streak of scale victories. It’s a very real and normal consequence of losing weight. Here, starvation mode and weight-loss plateaus are two sides of the same coin. Both refer to what happens when you weigh less — you consequently have a lower metabolism and burn fewer calories. While it’s a bummer to be handed this reality in a calorie-rich environment, the adaptation was useful in the past when food shortages were common.


If you drastically slash calories and are eating a very low-calorie diet (Think: less than 1,000 calories for women and less than 1,200 calories for men), “starvation mode” can actually be starvation. Starvation from chronic undereating can be counterproductive to weight loss and dangerous to your health. Eating very low-calorie diets for extended amounts of time puts you at risk for malnutrition because it makes it very difficult for you to obtain all the vitamins and minerals through food alone. Additionally, your metabolism drops way down to conserve energy, and your body breaks down valuable muscles and organs in a futile effort to maintain adequate fuel for your brain.


What happens when I’m dehydrated?


When the normal water content of your body is reduced, it upsets the balance of minerals (salts and sugar) in your body, which affects the way it functions. Water makes up over two-thirds of the healthy human body. It lubricates the joints and eyes, aids digestion, flushes out waste and toxins, and keeps the skin healthy.


Some of the early warning signs of dehydration include:


What happens when I’m overtraining?


Overtraining occurs when aggressive physical training is not accompanied by appropriate periods of rest and optimum nutrition. The most obvious symptoms are a decline in physical performance despite continued training accompanied by pronounced, persistent fatigue. Other symptoms include insomnia, change in appetite, irritability, restlessness, excitability, anxiousness, loss of weight, loss of motivation, inability to concentrate, depression, apathy, and changes in resting heart rate and blood pressure. In addition, cortisol levels can increase and the resulting high levels can lead to increased insulin, which reduces fat burning and increases fat storage. Chronic overtraining can lead to serious brain, muscle, and metabolic imbalances.