[ch4s3]

The idea that exercise doesn’t lead to fat loss is obviously false. If you’re eating a small surplus and increase your exercise volume you will lose weight. Clearly diet is a bigger lever, but plenty of exercises burn a lot of calories. Swimming and cycling are great for this.

[CJefferson]

Speaking as someone who, over a few years, lost about 50kg, the problem is that when I most needed to lose weight, my body couldn’t put up with enough cycling or swimming to burn useful calories.

I found it very funny that I spent about 2 years eating less so I could get better at cycling, then suddenly had to start eating more, once I was down 50kg, because I was getting faint on very long cycles.

[Fricken]

Cyclists typically have enough energy stored up to ride for about 90 minutes without needing to refuel. For me it's 90 minutes on the button, and it doesn't seem to matter what I've eaten beforehand or how hard I push myself.

[mu53]

Its recovery keeping up with expenditure. -1000 cal deficits limit recovering from muscle/ligaments soreness leading to build up of stress that is more damaging than simply not eating

[ch4s3]

At a certain weight, walking is the exercise.

[dataviz1000]

> 23 and 1/2 hours: What is the single best thing we can do for our health https://www.youtube.com/watch?v=aUaInS6HIGo

[kiba]

Your body rejigger caloric expenditure based on how much you exercise. It isn't a straightforward addition of physical activity plus basal metabolic expenditure.

[ch4s3]

Sure, you get more efficient but then you can just run a little faster or find a nice hill. If that’s boring go pick up something heavy. You can endlessly switch up training to find a thing you haven’t gotten used to yet. People act like there isn’t half a century of exercise science out there being put to use by athletes and regular people.

[nitwit005]

If you exersize a lot, your body will ask for a lot more food. Your body does not want to starve, and using a bunch of calories without replacement leads to that result.

At some point you have to control your diet. But, if you can control your diet, the exersize clearly isn't a requirement.

[throwup238]

I find that’s only true for the first few months of training while you get the beginner gains. Running half an hour a day was by far the biggest contribution to my weightloss once I finished the couch to 5K program and my diet settled down. My body adapted relatively quickly to the new regime just like it did with my sedentary lifestyle but YMMV.

Once you can run frequently without gorging afterwards, the extra 300-500 calorie buffer makes dieting a million times easier.

(Lost 35 pounds in 2024, 90% of it during weeks in which I ran consistently)

[Tade0]

A lot of that is based on assumptions from the 50s and 60s, which have been proven false in the late 80s by more rigorous studies.

When you increase activity, over the course of weeks, the body adjusts and does everything it can to not touch those fat stores.

Case in point: women who exercise intensely experience a reduction in the production of sex hormones, as that is energy intensive.

[ch4s3]

> When you increase activity, over the course of weeks, the body adjusts and does everything it can to not touch those fat stores.

Your body doesn't adjust endlessly. The technique to continue to shift body composition is called progressive overload, this isn't outdated and is the basis of most athletic training regimens.

Again I want to reiterate that no one is suggesting that diet isn't the foundation of fitness and controlling body composition. I am simply and factually stating that you can use exercise as a lever to achieve a calorie deficit. Arguing otherwise is to argue against thermodynamics, moving your body consumes energy and you body simple cannot achieve perfect efficiency.

[wizzwizz4]

That's really interesting – though it appears it's a general human thing. https://pmc.ncbi.nlm.nih.gov/articles/PMC7739287/

> TT and FT began to decrease starting 12 weeks in both moderate and high intensity exercise groups. Most significant decrease was at 12 weeks in high intensity exercise group

[thefz]

I hear this all the time from the exercise deniers and it makes me laugh, it's such a drop in the ocean compared to everything else that you will get by simply moving a bit more.

[drbojingle]

It's true. I jogged about 5-6 days a week for about 20-30 minutes a say a few years ago and the weight left me at a healthy tick. Naturally I could lose more with a better diet but I like eating so exercise it is.

[dilyevsky]

Yep, if you were at stable weight before, it’s trivial amount of daily exercise to create a 500 kcal deficit which will have you drop 1 lbs /week. People who say exercise did nothing are either lying about amount or intensity of exercise or compensated with increased caloric intake

[threeseed]

They never said that exercise doesn't lead to fat loss.

Only that it's a minor contributor and I would argue that's the case.

One of your examples, swimming, will put on weight as it will builds muscle mass which obviously is heavier. But one of the side effects of this is that your appetite will increase. And without careful diet management it's very easy for this exercise to be a net negative.

[elevaet]

It's not a minor contributor though, people vastly underestimate how much exercise our species is adapted for, how much we're capable of, and just how far off from that most of us live.

[tsimionescu]

It is, in quantities that are compatible with a modern lifestyle. Sure, if you're gonna run marathons every weekend, you will lose a lot of weight from that. But that's not possible to achieve while leading a normal modern life (full time employment, a relationship, children).

[elevaet]

I think it is doable in a modern lifestyle, but that most people don't make it a priority.

Most people waste a shocking number of hours out of every day scrolling, watching TV etc, and just take it for granted as part of a "modern lifestyle", but it's just an optional way to spend time, and not very productive.

I have full time employment, a relationship, children, and manage to get our for 1hr of running almost every day. (And find time to debate with strangers on HN XD)

[tsimionescu]

1h of exercise a day is great for your health, but that's still only going to be a minor contributor to fat loss. Adjusting your diet is going to have a much, much higher impact on weight loss than 1h of (moderate) exercise/day.

[ch4s3]

> One of your examples, swimming, will put on weight as it will builds muscle mass which obviously is heavier

Sure, but what you want is more muscle mass and less visceral fat so that's exactly what your want. Raw mass is too coarse grained to tell you much.

[tonyedgecombe]

>The idea that exercise doesn’t lead to fat loss is obviously false.

People tend to offset that energy expenditure elsewhere in their life, often without being conscious of it. The body is really good at balancing out your energy consumption.

If I go for a 40 mile bike ride today then I'm pretty sure I'll zombie out in front of the TV tonight.

[rrrrrrrrrrrryan]

I think you need to exercise in order to get past a weight loss plateau though.

If you simply cut back on calories by 20% - 30%, your body will adjust to the new norm within a couple months, and you just expend 20% - 30% less energy. You have maintain some baseline activity levels in order to continue burning fat.