Many people will amp up exercise in an attempt to lose weight because they know the law of thermodynamics that states that calories in must be fewer than calories out.  Knowing this, they will drastically reduce dietary caloric intake by adapting strange diets they won’t be able to stay on for the rest of their life.

At the same time, they start increasing the amount and intensity of exercise they do in an equally unsustainable manner.  Logically, this makes sense, unfortunately, it isn’t as simple as that.

In this article, we’ll discuss three ways exercise can get in the way of your weight loss.

1. Intense exercise and increasing the duration of exercise from what you did before will burn more carbohydrate calories as a primary fuel source, especially during the adaptation phase. Carbohydrates are the energy of intense movement.

All exercise, light to intense, will burn carbohydrates; however a greater percentage of fat is burned in the light to moderate aerobic exercise zone due to a state of metabolic efficiency being reached in carbohydrate burn state where carbohydrate metabolites aren’t overly produced and the slower fat oxidation systems have time to use the products of carbohydrate metabolism.

However, you’re still limited by carbohydrate capacity and aerobic training status (more aerobic enzymes burn carbs more efficiently).  Light to moderate exercise also causes less breakdown of muscle tissue, which is a good thing when thinking about weight loss and brings us to the next point.

 2. Relatively lean and fit people will already be able to push themselves intensely during exercise, requiring more calories on those exercise days than normal to replace glycogen stores (how glucose is stored in muscle) and rebuild lean tissue that was damaged from eccentric muscle activity and acidic denaturation of muscle proteins such as during high intensity exercise (resistance or aerobic-glycolytic).

This means they have higher calorie needs like anyone who has tissue repair needs, yet they’re consuming fewer calories for weight loss.  This leads to overuse injuries and overtraining syndrome, where stress hormones like cortisol increase to raise blood glucose to repair places of inflammation.  Stress, whether physical, physiological, emotional, or mental, and inflammation don’t go well with weight loss, which should be a relaxing, low-stress, anti-inflammatory state.

3. Intense exercise stimulates the body for lean mass gains. This means you GAIN mass, which requires more calories.  You don’t lose weight.  The number will not go down on the scale.  It won’t be a time when your body has calories to spare off your frame.

Some people will argue that the number on the scale doesn’t matter, it’s how fit you are.  This is true to an extent and is in agreement with the current research, as there isn’t much information on what happens to extremely massive people long term who are fit (not a huge segment of the population).

However, if you are extremely massive on a relatively small frame, it would theoretically require a lot more of your heart to pump blood through the extra space in your body, the lungs and kidneys to rid you of the waste products, and possibly increase blood pressure due to increased vascular resistance of blood vessels the heart must pump through.  Whether this is healthy and fit or taxing on organs is yet to be determined.

So in my opinion, excess weight is not good, whether fat or muscle.  You will not be as fast, agile, or aerobically efficient as your leaner counterparts, and your strength to mass ratio will decrease the more massive you get.  People might think you look good though, but that’s a sociological/contemporary phenomenon.

There are many parameters of fitness, including speed, agility, strength, muscular endurance, cardiovascular fitness, flexibility, balance, skill work and precision, as well as body composition.  It’s not always about body composition being the hallmark of fitness as popular culture may have you believe.

Knowing this, I stand by my comment in my interview with Megan Ware that exercise is often a detriment to weight loss if you do too much or too intense of exercise and are already pretty lean, ie near your ideal body weight.

If you are a beginner, you may get more leeway because you are not able to produce as much breakdown relative to the calories you are already taking in.  You also may not be able to push yourself to the intensity that breakdown occurs in your body, which spikes your calorie needs.  If you are spiking your calorie needs, you aren’t able to reduce them much from where you started, so the weight will not come off.

In fact, weight will increase if caloric needs are higher than what you are consuming, at least at first, due to the stress response and water retention.  Weight loss itself requires a consistent DIETARY calorie deficit in an unstressed state, so if you are telling your body to build muscle in your workouts, it will slow you down until it does.

How do I recommend going about fat loss?  It depends how much fear you have about getting out of shape during the weight loss process.

As a trainer, I know how relatively easy it is to get people into shape.  If you fear getting out of shape during the process of weight loss, then you probably are a candidate for a slower, “healthier (as currently recommended)” weight loss.  This will mean spreading workouts out as far apart as possible to limit losses in fitness yet still creating that dietary caloric deficit.

For example, strength training frequency may have to decrease so that you can lower your caloric needs enough to be able to cut the calories.  As your mass comes down, strength will also decrease, so you may have to lower the weight.

High intensity cardio frequency also will have to decrease.  Every time you workout, that increases caloric needs to repair yourself, so you will never truly achieve high caloric deficits necessary for faster weight loss.

If you are not already working out and very fit aka beginner or intermediate exerciser, it is unlikely that the amount of working out that you do will interfere with weight loss, even if strength training.  It is important for beginners to learn to adapt to the behaviors necessary for weight maintenance (ie exercising intensely and regularly) so that when they finish a low calorie diet, they will not regain as much fat weight back when resuming normal eating.

Most people reading this article will be beginners, so I do encourage exercise and diet at the same time for learning and psychological purposes and not because it makes weight loss faster—on the contrary.  For competitive athletes and highly active fitness enthusiasts who weight stall, things are a bit different.

Eating more on exercise days and less on non-exercise days is a great way to maintain your weight once you have lost it. This teaches a sustainable habit of balancing caloric intake with exercise expenditure while still eating a balanced, varied diet with all the food groups. You just modify the quantity of dietary intake while minimizing stress on the body, the essence of weight loss.  Weight maintenance is a different strategy than weight loss, however.

Unfortunately, exercise alone is pretty ineffective at resulting in weight loss.  I’ve seen it on the personal training side in both obese and lean individuals while also getting weight loss success in non-exercising clients who only seek nutrition counseling.  If an obese person does not modify caloric intake consistently below needs, they won’t lose weight.  If a lean individual over exercises and cuts calories, they will not lose weight but will just deplete glycogen stores and risk injury.

Weight loss is a complex process of creating a consistent dietary caloric deficit and maintaining light to moderate activity for the purpose of general health and circulation in an unstressed physiological state.  It is important to consider the calories relative to the exercise, as too few calories coupled with exercise doesn’t get you there faster.  Counter intuitively, it gets you there slower.

It is also not a linear process.  As you lose weight, your calorie needs decrease even more, so you may have to cut calories more to lose even more weight at the same rate or decide to be happy at the current weight while increasing lean mass body percentage with intense exercise (so you can eat more for a while before resuming the weight loss journey).  However, you will lose some lean mass with any weight loss, especially if already very fit.  The body has to stay proportional.  Super hero action figures are plastic toys, after all.

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Tags: aesthetics, exercise, obesity, overtraining, overweight, science, sports nutrition, weight loss, workout tips