Basic science tells us that to lose weight you must burn more calories than you consume. With that reasoning, it seems logical to assume that you will shed pounds if you work out because exercise burns calories. And while there is some truth to that statement, it’s not quite so simple. Yes, some form of physical activity on a regular basis is essential for health. However, if weight loss is the main reason that you exercise, you may be misleading yourself.
Here are some points to keep in mind if you’re considering including exercise in your weight loss plan.
Exercise and hunger hormones
Let’s start by taking a look at how exercise affects your hormones, thus influencing the relationship between exercise and weight loss. While you do burn calories through exercise (the amount will depend on what type of exercise you do), exercise doesn’t only affect the “calories out” end of the equation.
Studies have shown that exercise can have a pretty hefty impact on your hunger levels and appetite, often leading you to eat more. Not only that, but studies also suggest that on a psychological level, you are more likely to overeat after exercise, because you think that you can reward yourself with that cookie, extra serving, etc.
The primary hormone we’re talking about is ghrelin, otherwise known as the “hunger hormone.” T he manner in which ghrelin affects your appetite after exercise varies from individual to individual. Studies show that for some it might cause major surges in appetite, whereas for others it will have no effect, or could even reduce appetite after exercise.
The point here is to be aware of this possibility and make sure that you’re not significantly increasing your calorie intake after exercise, as this may negate any weight loss benefits.
Don’t lose weight, lose fat.
If you reduce your caloric intake without doing much exercise, you are likely to lose weight that consists of both muscle and fat. In fact, studies show that when you lose weight by calorie cutting alone, about 1/4 of weight loss is muscle. This happens because your body is forced to find other fuel sources, so it turns to not only fat stores, but muscle protein.
Including exercise in your weight loss plan will make sure that you are losing more fat than muscle mass, which is usually the goal. While it’s not exactly true that muscle weighs more than fat (a pound is a pound), the important difference is that muscle is about 18% denser than fat, so it takes up far less physical space in the body.
Paying attention to body composition via measurements and fat composition is much more accurate in determining how your body is changing than simply going by the number on the scale alone.
What matters more for weight loss, exercise or nutrition?
This might be hard to hear, but the amount of calories you burn via exercise alone is relatively small in the scheme of things. You burn most of your calories by naturally going about your daily activities. The rate of calorie burn is influenced by your BMR (basal metabolic rate ), which is the amount of calories you burn while at rest. In addition, you burn calories through the thermic effect of the foods you eat, i.e., calories burned just digesting and processing your food.
One study took a group of people who had just exercised to a buffet and asked them to eat the calories they thought they had burned during their workouts. Results showed that subjects ate about three times more than they had actually burned. This demonstrates that we tend to drastically overestimate the amount of calories burned during exercise, and increase our calorie intake according to this skewed perception.
Nutrition accounts for the majority of weight loss (perhaps as much as 70%), so while you should certainly keep exercising, be clear that nutrition is key.
Losing weight with cardio vs. weight training
Muscle is more metabolically active than fat, and burns far more calories when at rest. Many people wanting to lose weight (especially women) narrow in on cardio, often missing out on the massive weight loss benefits provided by strength training. Yes, cardiovascular activity is important for many reasons such as increased heart health and improved recovery time. But, if you think of calories in/calories out, you are simply not going to burn enough calories for effective weight loss only focusing on cardio. Instead of being shortsighted, understand how you can mold your body into a long-term, calorie-burning machine via weight training.
The impact that cardio has on your metabolic rate (the rate at which you burn calories) doesn’t extend far from the treadmill or stationary bike. When you strength train, however, you are actually changing your metabolic rate, which means you will burn more calories outside of your workouts in each and every one of your daily activities.
Weight loss issues: over-exercise, stress and weight gain
It is also important to understand that certain types of exercise can actually cause weight gain. While this definitely varies across people (due to genetics, metabolism, stress level, and diet), frequent, long distance, medium- to high-intensity cardio workouts can be particularly stressful to the human body. This has to do with the body’s cortisol reaction, your primary stress hormone. When our adrenal glands are under stress, they release a boost of cortisol to allow us to react accordingly. Cortisol is a fat storage hormone that stores fat especially around the mid-section.
If you are constantly and exclusively engaging in this type of extreme cardio, you could be prompting a chronic release of excess cortisol, which can actually cause weight gain or prohibit weight loss. This does not mean that you shouldn’t do cardio, but try working out in different ways, such as HIIT (high intensity interval training).
Other health benefits of exercise
Even though exercise is not necessarily a shoo-in for losing weight, you will still benefit from including it in your daily routine. Studies have concluded time and time again that exercise helps to prevent serious diseases such as osteoporosis, heart disease, certain types of cancer, diabetes, obesity, and more. In fact, one study revealed that regular exercisers have a 50% lesser chance of dying from these diseases than those who live a sedentary lifestyle. Not to mention, exercise is a major de-stressor and can help with mental and emotional health just as much as physical health.
Combining exercise and nutrition with stress management is the winning combination. Our health is influenced by a wide variety of factors, certainly including exercise. For some, this may come as a relief; rather than obsessively exercising, you can divide your efforts across the different categories necessary for both wellness and weight loss.