There are very few activities that let you meaningfully adjust your metabolism, the effective ones are thermogenic in nature. The only one of these that's at all fun is swimming. I spent all of last year trying to exercise to lose weight, the only thing that worked was lowering my intake.

People say weightlifting works, but it only helps when you're already relatively skinny. I know, I tried. You can be strong and fat. People say running works. It has a small effect but it's nothing to write home about. My sister runs marathons and still struggles with her weight. The problem is that exercise is maybe 10% of the picture, whereas intake is the other 90%. It's easy to fool yourself into thinking you're making progress on your weight goals by exercising, then throwing it all away on extra snacks. People get caught up in chasing mushy health goals and forget about the hard empirical facts.