Losing weight isn’t done in the gym.

We’ve just completed an entire blog series on training. You may have noticed that we’ve talked very little about weight loss, neither with strength training nor with cardio training.

Many people have the idea that if you train more, you automatically lose weight.

And while we encourage people to exercise regularly, it’s important to dispel this myth. We’ve observed that this high expectation often leads to demotivation when it turns out that weight loss isn’t necessarily a straightforward outcome.

In our previous blog post about weight loss, you could already read that weight loss is related to the energy balance. The energy balance dictates that if you expend more energy (calories) than you consume, you’ll lose weight. So you would think you could approach this by either consuming less (diet) or by expending more (exercising more). In theory, that’s true, but in practice, it seems to be more complicated.

We hebben zojuist een hele blogreeks geschreven over training. Het is je wellicht opgevallen dat we het weinig hebben over afvallen zowel niet met krachttraining als conditietraining.  

The unfair effort distribution:

The first reason why exercise is not the most effective tool for losing weight is that the time and effort you’ll need to put into it for significant results are enormous. Although there are nuances to this theory, it’s a good rule of thumb to assume that you need to burn 7000 calories more than you consume to lose 1 kilogram.

Intensive circuit training, such as what we often do at BOOST, burns 8 kcal/kg/hour. This means that someone weighing 70 kilograms would burn 560 kcal during a group class. However, it’s important to note that this applies only if you’re putting in serious effort. The value of 8 kcal/kg/hour is for “circuit training, including kettlebells, some aerobic movement with minimal rest, general, vigorous intensity.” The value for “circuit training training, moderate effort” is 4.3 kcal/kg/hour!

But let’s assume 560 kcal and that the average BOOSTer exercises twice a week. This means you’re burning an extra 1120 kcal on a weekly basis. You’ve had to work hard for 2 hours to achieve this. That’s excellent in itself. In theory, this should result in 5 kilograms of weight loss in just over 30 weeks.

However, when we put that effort into perspective with how easy it is to consume an extra 1120 kcal per week, it becomes clear why 1120 kcal per week is very little. Consuming an additional 1120 kcal per week looks something like this:

  • 1 large bag of Maltesers (1365 kcal).
  • 1 bag of 200g paprika chips (1076 kcal).
  • 6 cocktail snacks (636 kcal) and 4 glasses of wine (484 kcal).
  • 1 McDonald’s Big Mac meal (burger 525 + large fries 434 + mayonnaise 107 = 1066 kcal).
  • 1 25cm New York Pizza (1160 kcal).
  • Daily 5 pieces (7g each) of dark chocolate with coffee/tea (152×7 = 1064).
  • 1 slice (180g) of Tony’s Chocolonely Milk Hazelnut chocolate (1008 kcal).

Much of the above (or similar) can be consumed without even realizing it, especially during social gatherings or Netflix evenings. Adding these calories is much “easier” than burning them off. This brings us to the issue that some people seem to have the urge to compensate for burned calories. This effect is more pronounced in women and those who are already relatively slim. This is just one of the ways in which the body seems to compensate. Why training often results in less weight loss than calculated according to the energy balance is not yet entirely clear.

However you look at it, dietary adjustments appear to be the most effective for weight loss. Simply put, smaller interventions can have a greater impact. Simply shaking your head from side to side when someone offers you something is the best exercise for fat loss. Nevertheless, we recommend supplementing it with training.

Not for calories, but for what then?

Even though you don’t have to do it for the calories, exercise is indeed a powerful tool in your weight loss journey. Besides increasing your fitness level, which seems to have a protective effect on the negative metabolic consequences (such as cardiovascular issues) of overweight, exercising more also appears to prevent weight gain.

That’s important because the challenge of weight management lies more in sustaining weight loss than in losing it. Not only do most people regain the weight after 5 years, but they often end up heavier than when they started. This can be due to several factors, but one of the factors seems to be loss of muscle mass. When you lose weight, a portion of the weight loss will always consist of fat mass and a portion of “fat-free mass” (including muscle mass).

A low amount of muscle mass can have a significant negative impact on your health. Your body seems to want to restore that muscle mass after weight loss, and the easiest way to do that is by… you guessed it: eating more! This is where the problem arises! After weight loss, people tend to overeat until the lost muscle mass is restored. An additional problem is that this rebuilding process is slower than the breakdown. In the table below, you can see how this looks in practice:

Total weightFat massFat-free mass
Starting weight80 kg 20 kg60 kg
After weight loss70 kg (-10)14 kg (-6)56 kg (-4)
Relapse phase80 kg (+10)22 kg (+8)58 kg (+2)
Weight regain phase85 kg (+5)25 kg (+3)60 kg (+2)

The slow rebuilding of muscle mass leads to a lower fat-free mass during the relapse phase. This results in the weight regain phase, where people continue to overeat until it has returned to its original level.

In addition, there are, of course, multiple influencing factors such as disrupted satiety, but preserving muscle mass during a weight loss journey appears to significantly increase your chances of sustaining it! Training, particularly strength training, is a crucial weapon against the loss of muscle mass. Cardiovascular training does not have the same protective effect.

Do you want to lose weight sustainably with a healthy energy balance? With our BOOST Your Body program, that’s exactly what we focus on. It’s a 7-week tailored training program to level up. The push to get the most out of yourself, a game-changer if you want to make more progress, a last-minute fix for your vacation, or extra guidance because training or weight loss isn’t working alone.

Schedule a free trial class and discover how you too can lose weight healthily and sustainably.

So, is exercise important for weight loss or not?

The calories you burn through intense training are negligible on a weekly basis (especially due to compensation). However, it’s wise to do it. Losing weight, and specifically keeping it off, is extremely challenging for many people. Maintaining muscle mass seems crucial for the long term. Not only strength training but also protein intake, sleep, and stress affect the percentage of your weight loss that consists of fat mass or fat-free mass. That’s why at BOOST, we opt for a personalized and comprehensive approach. While nutrition has the most direct impact, our coaches are trained to look further and also consider indirect effects. Strength training is part of that!

Don’t Stop Here

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Afvallen, en nieuwe gezonde gewoontes bouwen

Afvallen, en nieuwe gezonde gewoontes bouwen, het kan ongelofelijk lastig zijn. Maar waarom is afvallen moeilijk en waarom duurt het zo lang? We laten je zien welke blokkades hier een rol kunnen spelen.

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