Do We Burn Fewer Calories as Conditioning Improves?

The wall of efficiency hurts when you hit it.

Many people complain about how suddenly they will stop losing weight once they reach the dreaded stage of physical fitness, we, in the industry, call “a plateau.” It is often a complete shock to the folks out there who had been benefitting from “beginner’s gains,” which is the initial increase of performance and decrease in weight many novices experience simply due to their body going from zero to hitting the gym a few times a week and making marginally better dietary choices.

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Once the body catches up with the program, those performance gains and the shedding of pounds seems to disappear.

So, what causes these flatline periods of no weight loss? How can we avoid them? And how can we shake it up, so that we can start burning more calories again and lose those stubborn pounds?

To answer those pressing questions, we must first understand how our metabolism works.

Base Metabolism

Your metabolism is not as mysterious as diet gurus would like you to think. It is the process by which your body converts food into energy. Sure, it’s a complex process, chemically speaking, but basically your body breaks down the food, combines it with oxygen and boom. Those little reactions are the energy upon which your body depends to operate.

Your body uses these little explosions to run, jump, and exercise. It also uses them to breathe, circulate your blood, regenerate cells, fight colds, and do all the other things it does without your permission, let alone awareness, to keep you alive.

While those diet gurus want to confuse you into thinking every aspect of your life affects your metabolism, from the type of food you eat, to the type of blood that runs through your veins, the truth is there are few things that can “slow down” or “speed up” your metabolism. And most of those things are out of your control.

Your body size is a factor. The larger a person is, the more calories they burn to sustain themselves. Your sex is a factor. Men burn more calories than women due to their genetic propensity to have more lean body mass. Your age is a factor. Because muscle burns more calories at rest, your metabolism slows down as you get older and lose muscle mass.

Thermogenesis is another factor. These are the calories you must burn, well – to burn calories. Breaking food down (digestion), transporting it around your body, and storing it requires about 10% of the energy you consume every day.

Without major medical intervention, you can’t really change your bone structure, sex, or your age. You cannot alter the law of thermodynamics. (Though, if you could, weight loss would be the least of all our concerns.) What you can control is your food intake and your activity output.

Physical activity is something that you can alter to burn more calories (aka, speed up your metabolism.) Working out, walking around, lifting weights and active endeavors all burn varying amounts of calories, and those are the big ones we focus on.

But the small things you don’t realize you are doing, because it is just part of your day-to-day life, such as getting up out of bed, walking through your house, typing fire responses in lifting forums, and even fidgeting, also burns calories.

So Why Does Metabolism Seem to Slow Down?

Once people adjust their intake and output levels, they often have a nice stretch of weight loss. Then it seems to stop, out of nowhere, so they look for answers. The truth is your metabolism is still doing its thing. There are only a few medical issues, for example: hypothyroidism, that have a large impact on its speed.

Weight gain is a complicated topic that involves many factors like stress, hormones, sleep, and your genetics. All of these things, however, aren’t so mysterious – they have a direct effect on energy balance. Energy balance, aka thermodynamics, is a law of physics. In the end, it is still a matter of intake and expenditure, not magic.

In other words, your metabolism hasn’t “slowed down,” a part of your energy equation has changed, and now you must find the variable and re-adjust.

A Matter of Physics

One reason weight loss slows down or comes to a halt, is because you simply have less mass. Your body has adjusted to its smaller size and needs less calories to maintain itself. Congratulations, you have achieved equilibrium.

To combat this plateau, you must simply lower your calorie intake or up your activity level. You can make this decision by assessing your progress and your feelings. Do you feel good where you are at?

Then stay where you are and enjoy your life. Do you feel like you want to take your training to the next level? Then, start with activity. Do you feel like your training is still sufficiently tough? Try to cut a few calories.

What About Efficiency?

Another part of the energy balance equation is efficiency. In the beginning, people expend more energy doing tasks because they aren’t doing them properly. They are “throwing their back into it,” so to speak. Their form isn’t perfected, so their bodies burn extra energy to compensate for this.

As they progress in their training, they learn how to adjust their gait, brace their bodies for a lift, breathe at a calmer, steadier rate and so forth. All these tweaks make the body more efficient at its task and therefore needing fewer calories to perform it.

To combat this issue, you can simply kick your training up a notch. Add an extra set, or give yourself an extra five to ten-minute cardio power challenge post workout. You can also make minor changes, like taking the stairs or parking your car at the far end of the parking lot. It all adds up.

Metabolic Adaptation

Studies are now showing that adaptation plays a bigger part in a plateau, once the physical activity level is very high. This isn’t the simple efficiency of your body adjusting to the exercise or hitting a limit to the calories burned for a specific workload. Metabolic adaptation is more like the glass ceiling of human energy expenditure.

Basically, what some experiments suggest, is that at lower levels of activity, exercise plays a big, linear role in burning calories. However, at high levels of exercise, those calories taper off and flatline. But where do these calories go? If you are doing more work, how are you not also burning more calories? You can’t defy the Law of Thermodynamics.

Researchers suspect the missing calories aren’t really missing at all, but that your body begins doing less busywork to compensate. For instance, perhaps you aren’t fidgeting as much. Or, you may become tired out and start sitting more than you used to when you’re not in the gym. Small shifts in non-exercise related activity may be cutting the cost.

Other theories are that your body steals from its non-muscular functions, like hormone development. Female Athlete Triad is a condition that occurs when females suffer a drop in estrogen due to low energy availability. Automatic tasks that we take for granted, cell replication and repair, immune system response, hair and nail growth, etc. may all conceivably be suffering the consequences of excess expenditure.

More research is needed to get into the specifics of exactly how much exercise that is, and what systems are being withdrawn from to pay for all of the extra activity.

Am I Too Efficient to Lose Weight?

Short answer: probably not.

Most people in the initial phase of weight loss haven’t adapted their bodies to exercise enough to plateau on calories because one simply can’t go from zero to elite athlete and not lay themselves out within the first few weeks. Athletic effort takes time to build. If you’ve never run in your life, a marathon isn’t going to be your starting point. A mile-long walk or jog will suffice.

Moderate activity levels – the level at which most people looking to lose weight aspire to – are still correlated positively with a caloric deficit. Some weight lifting and a few runs during the week would be considered moderate exercise.

However, if you find yourself in the gym every day, endlessly toiling on the Stairmaster for an hour and a half, you might need to shake it up. Stop climbing to nowhere and start resistance training. More muscle mass will help you burn more calories at rest.

Conversely, if all you do is lift a few sets of heavy weights, then walk to your car to drive to work and sit at a desk, you might want to add a little Tabata or a cardio session a few times a week for a calorie-burning boost.

Metabolic adaptation is not a catch-all reason for why people on their weight loss journey plateau. It is primarily associated with people who exercise a lot. To use it as an excuse a year into your fitness journey is as silly as blaming some weight gain in the first month or two on muscle weighing more than fat. But since we are becoming aware of the phenomenon, we can better assess whether people need to adjust their diet instead.

The bottom line is to assess yourself honestly when you come to a weight loss plateau. There is a part to the energy balance equation that is out of whack and the sooner you figure it out, the better. You might have lost enough initial weight to now require less calories.

You may have lost weight, but are sitting at a high bodyfat, low muscle ratio. You may need to change your body composition and build more lean muscle mass.

You might be inadvertently eating more to compensate for all of the activity, or engaging in more “downtime” to rest than you realize. Or, in some instances, you might simply need to train a little harder to reach the next goal.

If you have thought about it and it turns out you are working out double-time and not losing any weight, I’d like to ask you to consider if you truly need to lose any more weight. If you are within a healthy weight range for your body type, and you are eating well, and working out for hours and hours, you need to examine why you feel you need to lose more weight.

Is it a goal you picked without researching? Do you have health problems related to your weight? Do you think everything will be perfect if you could just lose five or ten more pounds? Are you struggling with disordered eating or anorexia?

Sometimes the psychological components of how we see ourselves and how we perceive fitness can lead us down a dark and ultimately damaging path.

Sometimes fixing an energy imbalance is as simple as changing the type of exercise you do to change your body composition, instead of being obsessed with the actual weight itself. Sometimes it just means dropping a few extra treats during the week. But, sometimes, too much is too much.

Energy imbalance has a cost. Some people’s bodies, even high-level athlete’s bodies, are never going to look like the models on Instagram. Some larger-framed people are never going to reach an arbitrary weight goal less than their healthy range.

Always remember you are doing this to be healthy and fit, not to simply become a number on the scale.