Why Does Exercise Make You Lose Weight?

Great Exercise

The common held conception is that the more you exercise the more you lose – right? Well partly so, but it is a little more complicated than that as i will convey in this article. As a Los Angeles Personal Trainer i am avidly in pursuit of research that can translate to better and more efficient results for my clients.

The most useful insight in that context is in the area of exercise and weight loss. It is in what the exercise triggers in our bodies that sets the tone for weight loss, and not so much the exercise. Physical function/activity boosts the body’s internal messaging system (the in-built brain computer), to be more sensitive to appetite surprising hormones Leptin and Insulin, which is more critical to weight loss than just the calories the activity burns.

Leptin is the new kid on the block, having been discovered in 1994, but one of the most important hormones for assisting in weight loss. It is one of the reasons why with all the modern diets around today, that cause people to yo-yo in their weight loss journey, as each time they go on a ‘diet’ cycle they unbalance their Leptin levels, which causes the body to rebound and hence gain weight.

Leptin hormone is most abundant in adipose tissue (body fat), so the more overweight a person is the more their body secretes. The main function of this key hormone is to signal to the brain/body when it has been adequately fed, which regulates energy stores in the body through the hypothalamus to maintain balanced body weight.

Leptin can at first glance appear to be desirable to have in evaluated amounts, as it suppresses food intake at the same time as increasing the metabolic rate. However, people that are overweight and produce higher Leptin levels become leptin resistant and encounter a similar problem as those that develop insulin resistance.

To explain this further one must have an understanding of the way that leptin communicates with our body. It is part of our “internal messaging system”, sending signals to the brain when enough leptin has been secreted by the fat cells, resulting in a state of satiety and a feeling that we can stop eating.

With our modern day obsession of perpetual diets and the latest and greatest food craze of the week,all mostly promoting a reduced food supply, the result is a society with decreased leptin levels as our bodies adjust to the lowered level of food intake. The adage is the less you eat, the more your body stores by way of stored calories (body- fat).

On the other hand there is a tendency to overeat all the “wrong” foods, that is processed and high glycemic foods, that further scramble the hormonal signals of the body, with the result that our leptin receptors become unresponsive to leptin’s effects. When in this state the body is leptin intolerant, and does not send it’s usual signals to the hypothalamus to tell the brain that it has been fed sufficiently, or reached a state of satiety. This is the catch, although blood leptin levels are high, brain levels are low which leads to uncontrollable food binges, overeating and tremendous weight gain. The brain is misled to think the body is in starvation mode and tells it to store more body fat. This is what i term the “vicious cycle”. In its balanced state leptin is the most powerful natural appetite suppressant there is, but when unbalanced it can’t do what it is supposed to, and this leads to cravings for sweet foods. This is nowhere more perfectly exampled that in overweight to obese folk, as they seemingly do not eat a lot, but crave all the wrong foods.


The benefits of exercise are far more wide reaching than simply the calories a certain activity burns. A study at the University of Florida has shown that exercise reinforces the balance of leptin and it’s effectiveness, and in turn insulin regulation. High Intensity Interval Training (HIIT), which uses short bursts of higher output exercise interspersed with lower intensity, is of most benefit in hormone balancing and regulation.

Kick up your training a notch, buy a heart rate monitor and see the results multiply.


Leave a Reply