This blog article is in response to The Science Is In: Exercise Won't Help You Lose Much Weight.
Basically, this article can be summed by it’s own summary which states:
“Exercise is excellent for health; it’s just not that important for weight loss. So don't expect to lose a lot of weight by ramping up physical activity alone.”
Now, this article raises two huge questions:
1. If you are trying to lose weight, should you even bother exercising?
2. If so, what kind of exercise should you do?
I’m going to go through all of the article’s main points to answer the questions of whether you should exercise at all and what kind of exercise should you do (if at all)?
The first main point of this article is that exercise may not help you lose weight because…
"Exercise accounts for such a small portion of your daily calorie burn."
The article states which is true that 10-30 percent all our calories burned come from fidgeting, holding our posture, standing, walking, and finally, your exercise.
So, we’re going to be a little generous and let’s say 5-15 percent of your calories burned come just from exercise. The problem is 5-15 percent of calories burned isn’t going to be enough to help you lose all of the weight you probably want to lose.
Now, if you could burn 20-30 percent, that would be really powerful, and there is a way we can do this. That way is called cutting calories through dieting. So, it’s much more simple to cut calories to help us burn fat, than it is to exercise those calories off.
The article presents a good case for showing us the limitations of exercise in burning calories.
Main Point #2: We naturally eat more when we’re exercising without noticing we’re eating more.
Check this study out: These people were in this research study for one year. They were overweight men and women. They averaged 55 minutes on the treadmill 6 days out of 7 days of the week.
How much weight do you think they lost? I think a reasonable guess would be at least 10 pounds, but potentially 20 to 30 pounds. They actually lost an average of 3.5 pounds. When we divide that into 12 months, they lost an average of 0.3 pounds per month. An hour a day of exercise is a lot of work to do to lose less than half a pound per month.
It does bring us back to the point that cutting calories through dieting is still the most powerful way to drop weight.
Main Point #3: Our metabolisms slow down the more weight we lose.
While this point isn’t actually mentioned in the article, it is mentioned in the corollary article that this article comes from which is titled: Why You Shouldn’t Exercise to Lose Weight, Explained with 60+ Studies.
Have you ever dieted down, and lost a lost of weight the first week, then over the next couple of weeks and even months, weight loss slows down and eventually plateaus? Part of that is very likely your metabolism slowing down.
So, for instance, if you started out with a 300-500 calorie deficit, you’ll surely lose weight from that. But it is possible for your metabolism to slow down by a couple hundred calories, and then at that point, you no longer have a significant deficit to lose much if any weight. This is why it gets even harder to lose weight to the end because your metabolism is fighting you.
In conclusion: this is a good article and highlights the most important ways that you can actually lose weight which is by cutting calories through dieting. It challenges a lot of the perceptions that exercise is critical to lose weight.
But, if you read the article, you’d come away with the impression that you wouldn’t really need to exercise to lose weight, and you’d be correct. I mean, the corollary article which this article stems from is called: Why You Shouldn’t Exercise to Lose Weight, Explained with 60+ Studies.
However, there is a quote in both articles which is interesting. I want to see if you can spot the dilemma in this quote.
"If a hypothetical 200-pound man added 60 minutes of medium-intensity running four days per week while keeping his calorie intake the same, and he did this for 30 days, he'd lose five pounds."
Did you see the problem with this sentence? The authors acknowledge that if you keep the calorie intake the same (which means we’re not changing the diet at all), and, if you actually exercise, you will lose weight.
But aren’t they trying to say the opposite of that?
Let me tell you what the authors are assuming.
Main point number 2 states: We naturally eat more when we’re exercising without noticing we’re eating more.
My question to you is, how could you overcome this?
The way we can actually know if we are eating more is by recording our food intake and being extremely scrupulous with the amount we consume. In other words, you need to be very accurate with counting calories. You should consider using a food scale and recording your intake.
If you do this, you can unlock the full potential of exercise-induced weight loss which is exactly what the article implies with the quote above.
My original question was: If you’re going to try to lose weight, should you even bother exercising?
Contrary to the original article’s title which is: Why You Shouldn’t Exercise to Lose Weight, Explained with 60+ Studies, you absolutely should exercise to lose weight. The reason why is that when you are very carefully controlling your calories, even they acknowledge that if you’re not changing your diet and you exercise, you will lose weight. We’re not finished though.
The third main point was “Our metabolisms slow down the more weight we lose.”
One way that we can counteract this is to do resistance training and to lose weight slowly. Doing that might completely prevent metabolic slow down, and at the very least it should help mitigate metabolic slow down.
Not only that, people who resistance train lose substantially more fat, keep or build more muscle, and have higher bone mineral density, compared to people who are only dieting.
The first main point of the article was that exercise accounts for such a small portion of your daily calorie burn.
The way to counteract this is to do cardiovascular exercise, but it can’t just be any cardiovascular exercise. It should be significant enough to induce a reasonable calorie deficit, generally in the range of 400 to 700 calories, depending on your body weight. I recommend using a heart rate monitor which incorporates your weight to give you the highest accuracy possible.
The two big takeaways are:
1. You need to closely monitor and accurately record how many calories you consume.
2.You need to accurately estimate how many calories you burn with exercise. The research is clear: people notoriously overestimate how many calories they burn, and they underestimate how much calories they consume. Don’t fall into these traps!
In fact, we know from the research that the more overweight you are, the more you’ll underreport how much food you actually consume.
There’s an ingenious method used in the research called doubly labeled water which swaps out the standard oxygen and hydrogen atoms in water or H20 with oxygen and hydrogen isotopes, that after all is said and done gives you a very precise measurement of how many calories you burn, and thus how many calories you need to consume to maintain your weight.
What all those studies have found is that the more overweight you are, the more you’ll underreport how many calories you actually consume.
In one of the landmark studies in 1986, the lean subjects were found to be extremely accurate with how many calories they reported, but the obese subjects reported on average of 835 calories lower than what they were actually getting in. (2)
The article claims that the studies it examined showed that exercise didn't really help people lose much more weight when people were dieting or only exercising. However, all of the subjects in their studies were overweight or obese when beginning their weight loss efforts (for those studies which weight loss was significant). This made it more likely that many of their participants underestimated how many calories they consumed.
It's very possible these same overweight or obese individuals overate when exercising (but ultimately were at enough of a deficit to still lose weight). Because metabolic slowdown was even less of a factor for exercisers, this could have been a significant contributor why individuals didn't lose as much weight as expected when exercising.
We are designed to move and exercise. It’s fun to compete, play games, and to get a six-pack. You can't do this without exercise. You get the best natural high after exercise and which combats depression, lowers blood pressure, lowers LDL cholesterol, makes you smarter, improves your memory, and makes you look, feel, and be way more awesome. In other words, you’re crazy for giving up your exercise to help you lose weight.
1. McTiernan A, Sorensen B, Irwin ML, Morgan A, Yasui Y, Rudolph RE, Surawicz C, Lampe JW, Lampe PD, Ayub K, Potter JD. Exercise effect on weight and body fat in men and women. Obesity (Silver Spring). 2007 Jun;15(6):1496-512. PubMed PMID: 17557987.
2. Prentice AM, Black AE, Coward WA, Davies HL, Goldberg GR, Murgatroyd PR, Ashford J, Sawyer M, Whitehead RG. High levels of energy expenditure in obese women. Br Med J (Clin Res Ed). 1986 Apr 12;292(6526):983-7. PubMed PMID: 3083978; PubMed Central PMCID: PMC1339917.