The results are unsurprising... I gained 15 pounds over the next 6 months, and am now overweight.
Exercise obviously plays a role in weight management. There's truth in the "you can't outrun your fork" meme, and it's good to remind people of the greater importance of diet for weight management to counter the widespread myths about exercise being some cure-all here. However, I do worry that overly reductive takes risk swinging the pendulum too far in the opposite direction.
Do you remember whether your diet changed at this time as well?
Some other anecdotes shared here seem to share a similar theme, that exercise helps in losing weight on a more meta-level by shifting yourself into a generally healthier mindset which, in turn, seems to help you eat "healthier" foods, which is probably a proxy for "low-calorie foods" like fruit and vegetables. Maybe when you're sedentary it's easier to reach for the bag of potato chips?
Because following that logic, exercise supposedly does not work if you want to lose weight. But if every study around aerobic exercise arrives at that conclusion, why aren't the majority of athletes overweight? Where are the fat runners?
Is this a survivor bias? (Fat people even with great aerobic capacity end up hurting their joints so they stop running)
Is it because the addition of exercise generates other kind of changes in the body, like less insulin resistance, and overall more signals in the body to burn fat rather than store it?
Do runners spontaneously change their diets once they get used to their new lifestyle? Maybe the food they used to eat, both in amount and in composition, makes them uncomfortable so they start making lasting changes?
Yes, it does look like running a static amount every time has diminishing results. But, overall, people who run tend to be less overweight. And a lot of overweight people who start doing exercise and stick to it, tend to lose the weight, or at least they lose fat and gain muscle.
The "much" is carrying a lot of weight, so to speak, in your comment. As a reference I went from running ~25 miles a week to just walking a fraction of that as I've recovered. I did keep up my other non-cardio calisthenics throughout, though.
Some napkin math suggests I was over my calorie target by just shy of 300 calories per day over the course of this time period.
If we assume 3500 additional calories is 1 lb of fat stored on your body, then 3500/300 = 11.6 days you gained 1lb
Assuming 6 months is 180 days, then 180/11.6 = 15.5 lbs over 6 months
I’m my experience people severely underestimate the effects of having more muscles mass and the changes it can cause when you lose some from lack of training.
It also bleeds into peoples thinking. People view exercise as a way to lose weight. And eating less is, rightly, a more efficient way of losing weight. But body composition really matters not just for losing weight, but just life in general.
But I've had no problem keeping weight off by just adjusting the amount that I eat. However, if I upped the cardio, I'd be able to (and want) to eat an extra 500-600 calories to compensate, and still lose weight.
I swear I can maintain weight eating more than what I supposedly burn while active, which could make sense if you buy into the whole "your metabolic rate can be work-hardened" concept.
It's easy to calculate how much energy it takes to propel a given weight 5 miles. It's hard to tell how many calories a person burns to produce that energy. Your ratios of aerobic to anaerobic respiration are going to impact that wildly, which will depend on how much oxygen your body can absorb and how quickly you're burning through oxygen. There's a huge gap in the amount of energy cells get from each. Aerobic respiration produces up to 38 ATP per glucose, while anaerobic produces only 2 ATP per glucose.
Running form probably plays into that as well, if you've got some kind of suboptimal gait or you're swinging your arms a lot or something like that.
Yep, my form is atrocious and inefficient due to bunions and Morton's toe which has evolved into hammer toe.
I'd argue that I burn calories more efficiently, however :)
First of all, while a 3k run isn't going to do much to burn off that slice of cake you had with lunch, if you transition from a generally inactive lifestyle to a generally active one (eg, by getting into running as a hobby), you can cumulatively burn a decent amount of calories. Cardio as a hobby is not for everyone, but I thought it wasn't for me until I gave it a shot and found I really enjoyed it.
There are also psychological advantages of incorporating exercise into a weight loss regime. I started eating better after, and partially because, I started exercising. When you work out a lot, you start to enjoy feeling healthy (or at least, thinking of yourself as a healthy person), and you start to realise that junk food is working against that.
Finally, weight loss should not be your only goal if you are interested in getting healthier. It's true that you could lose weight by being very sedentary and eating very little, but I suspect that would bring its own health problems.