Losing weight by working out

Losing Weight by Working Out? How much does exercise help

Losing weight by working out. What is the impact of exercise on weight loss?

By Coach Hunter Bennett

When people decide to change how they look and feel, exercise is often their first step – which is great.

Exercise improves mental and physical health, increases confidence and self-esteem, and obviously increases the amount of energy you burn each day, which does aid fat loss.

However, the extent to which exercise creates fat loss is often overstated.

Losing weight by working out: Calories in vs Calories out.

The fundamental principle of weight loss comes down to energy expenditure – i.e., calories in versus calories out.

To lose weight you must eat less calories than your body expends, creating a calorie deficit. Over time a sustained caloric deficit leads to weight loss.

Exercise and Caloric Expenditure

Losing weight by working out

Regular exercise increases the amount of energy you burn, effecting the “calories out” side of this equation. As such, exercise can have a direct impact weight loss by facilitating a calorie deficit.

Aerobic exercises like running, cycling, and swimming, as well as weight training and high-intensity interval training (HIIT), all increase caloric expenditure.

Moreover, weight training also provides an additional benefit by causing a small increase in your basal metabolic rate (BMR) – which describes the number of calories your body burns at rest. This creates a more favourable environment for sustained weight loss.

Taking these into consideration, it is clear why exercise is often the first step people take in a weight loss journey.

However, it shouldn’t be the only step they take.

How much weight can you lose through exercise?

While the link between exercise and weight loss is clear, its ability for it to create long-lasting weight loss is limited.

In fact, research examining the effect of exercise on weight loss report an average of ~2kg of weight loss after exercising for ~ 200 minutes per week for 6-12 months.

This equates to less than half a kilogram of weight loss per month.

Although I should note that weight loss does increase with the amount of exercise you do.

For example, some research has shown exercise to create ~5kg of weight loss after 17 weeks when exercising 7.5 hours per week (~65 minutes per day) – however, this amount of exercise might be unrealistic for many.

Why exercise has such a small impact on weight loss is believed to come down to two main mechanisms:

  1. Energy compensation: a phenomenon where you subconsciously decrease your energy expenditure throughout the day to account for increases in energy output from exercise. This can come in the form of less fidgeting, less movement, or less activity due to feeling tired and lethargic.
  2. Post exercise hunger: describes the process where hunger increases in the hours following exercise to maintain a constant energy balance. This can lead to increases in snacking and larger portion sizes, which ultimately negate the energy you burnt through exercise.

It is important to note that these two things don’t occur to the same extent in everyone.

Some people experience them severely, while others barely experience them at all. In fact, this is thought to explain why some people see great weight loss through exercise alone, and others don’t.

The good news is that even if exercise isn’t the best weight loss tool, it does have an important place in every weight loss journey.

Working out for weight maintenance

Losing weight by working out

There is a large body of evidence suggesting that after a period of weight loss, most people regain more than 50% of their lost weight in two years, and by five years, regain more than 80% of the weight they lost.

While exercise may not have a huge impact on weight loss, it does have a MASSIVE impact on weight maintenance.

Obviously, exercise does burn calories, and this does contribute to a stable weight. But it also offers a host of other benefits.

Regular exercise helps control appetite by regulating the hormones that influence hunger and feelings of fullness. It also boosts mood and relieves stress, which can reduce instances of emotional eating and snacking.

Importantly, less physical activity is required to stop weight gain than create weight loss. As little as 150 minutes of exercise per week is sufficient to maintain body weight after a period of weight loss.

Losing Weight by Working Out: Why Reducing Calories Takes the Lead

While exercise plays a small role in weight loss, what you eat has a much larger impact.

If your goal revolves around losing weight and changing your body composition, then reducing the “calories in” side of the equation is the most important factor. Moreover, this reduction in calories doesn’t seem to come with the same compensations we discussed above.

As an example, a well-known 2012 study compared three weight loss interventions in overweight women across a 12-month period. One group performed 45 minutes of exercise five times per week (225 minutes total per week), another ate a diet that put them in a deficit of 500 calories per day, while the last group did both the diet and exercise.

After 12 months, the diet only group reduced their body weight by 8.5%, the exercise only group by 2.5%, and the group that did both by 10.8%.

When looking at this data, we should note that while diet was the largest driver for weight loss, exercise did contribute, and those performing diet and exercise saw the best results.

Importantly, these are the individuals who are also much more likely to keep maintain weight loss off long-term.

Losing weight by working out: Take home message

While exercise may not play a huge role in your weight loss journey, it is integral for long term weight management. With that in mind, if you do have weight loss goals, your best bet is to focus on diet and exercise to get the best results.

Want to read more? Check out our article on minimalist strength training

Book a session

Contact us now to book in a Personal Training session or join our new gym!

Book Now