Can we outsmart our metabolism?

For many cyclists, finding the perfect balance between weight and power is a difficult quest. Some try to outsmart nature by training hard or radically changing their lifestyle.

The path to achieving the ideal weight-to-power ratio is undoubtedly less bumpy when we understand the factors that affect our body mass. Obviously, the food we eat, combined with our energy expenditure, can produce certain results, but this duo does not fully explain weight loss or gain.

Basal metabolic rate

From a metabolic point of view, the key factor in weight gain or loss is undoubtedly the famous basal (or basic) metabolism. Roughly speaking, this is the energy that the body expends to perform all its vital functions, without us lifting a finger.

For example, if I need 1,200 calories per day to live while lying down doing nothing, and I consume 1,500, I will have a surplus of 300 calories at the end of the day. Simple, right? Not so much...

Despite this seemingly simple calculation, it is very difficult to know our basal metabolic rate. In addition, it can vary considerably between two individuals of the same weight, age, and body composition. There are certainly websites that offer to measure it, but the results remain fairly approximate. According to some specialists, this interindividual difference could be as high as 10% and is attributable, among other things, to the energy use of our organs.

As many food and pharmaceutical companies have realized, offering solutions to increase basal metabolism could be a guarantee of weight loss. But can we really take a pill and lose weight while watching our favorite show on the couch? If it were that easy, we wouldn't be seeing a global obesity pandemic...

What weighs in the balance

The differences observed between metabolisms can be explained primarily by each individual's body composition. A large amount of muscle compared to fat mass increases metabolism. However, as we age, muscle mass can decrease depending on our lifestyle; this is one of the reasons why metabolism tends to slow down.

What's more, lifestyle habits can also explain much of the weight gain that surprises people after the age of 40. Among other things, there is a decrease in physical activity coupled with poorer control of hunger and satiety signals. In other words, the imbalance between our food intake and energy expenditure explains weight gain more than a marked decrease in basal metabolism. 

How can you have the highest metabolism? Currently, tall, muscular, active, and young individuals have the advantage. Aside from all these factors, genetics also play a role, including our ethnicity.

Outsmarting nature

Knowing what really influences basal metabolism, the question still arises: can we speed it up by finding ways to minimize genetic factors? Dr. Google is full of information and tips that seem to work: increasing our consumption of caffeine or green tea, getting enough sleep to keep our appetite hormones awake... However, none of these techniques really work in the long term. Some may temporarily alter our metabolism, but never enough to bring about noticeable and permanent changes. As for "fat-burning" supplements, they may slightly help some people burn calories faster, but not significantly enough to make a real difference.

The question we should be asking ourselves is: how can we maintain our metabolism at its current level, knowing that it is likely to decrease with age?

Building up good muscle mass that is compatible with our sport and maintaining it over time is a good first step. Eating enough fiber (vegetables, fruit, whole grains) and drinking plenty of water every day activates our digestion and thus our metabolism.

The best way to preserve it is therefore to keep it elevated at all times, in particular by continuing to exercise, which activates our heart and other vital organs.

Conversely, drastic diets that result in significant weight loss will tend to slow down the metabolism: the body will then get used to using less energy to function, for fear of running out soon.

As always, improving our lifestyle habits is a better guarantee of success than trying fad diets and expensive supplements. We don't cycle to change our metabolism, but for the lifestyle that comes with it and for the well-being that this sport brings us. Getting back to basics, following your intuition when it comes to nutrition, and enjoying exercise are personal choices that even our genetics cannot change.

* USDA Human Nutrition Research Center on Aging at Tufts University