Repeat after me:
Diet determines size, exercise determines shape.
Diet determines size, exercise determines shape.
>For starters, exercise—at least the kind most of us do—is typically ineffective for weight loss
>In studies where exercise has produced meaningful weight loss, participants burned at least 400 to 500 calories per session on five or more days a week
The reason why I've always believed claims such as yours are bullshit is because I do the kind of exercise that produces meaningful weight loss when the scales tip too far in the wrong direction.
https://www.mayoclinic.org/healthy-lifestyle/weight-loss/in-...
I get about 200 per 20 minutes on the elliptical with a fairly relaxed pace and low resistance.
Running on a treadmill for an hour would be anything from 6 miles (10km) to 12 miles (20km) for some of the very best runners, so 600 calories to 1200 calories.
But there's a second-order effect of the exercise, since it's mostly calisthenics; when my weight goes up, my performance immediately deteriorates. That mental negative feedback usually corrects my eating misbehavior within a day. It's far more weight-affecting than the calories burned, by changing my eating.
The fact is though, generally speaking, you're not going to outrun a bad diet with exercise...
Before I started climbing I burnt off 25 pounds that I accumulated up after I broke my leg and spent 2 years largely sedentary. I did it using high intensity interval training: sprinting stairs, over a period of 10 weeks.
I took this approach not based on any study, or advice but because in the past, when doing HIIT with a healthy body weight, it was hard to maintain a diet good enough to keep up.