What they should be thinking is: going for a walk around the block, not getting the car for close by errands, not taking the elevator, going for a bike ride, etc
Likewise for diets. Those who spend their New Years resolution momentum eating baked chicken and broccoli for a week or completely cutting out carbs will shortly find themselves failing completely and binging ice cream or whatever. Rarely do you see sensible advice like "keep your same diet habits, but cut out soft drinks", or "if you engage in late night boredom-eating, try binging vegetables instead."
Unfortunately, humble and incremental changes in habit seem antithetical to our society's affection for (unrealistic) sweeping, dramatic transformations.
I honestly have done this for the endorphine boost, but overall I’ve lost just under 11kg in about 10 months and I’ve really started to notice my belly go down, and I can actually see muscle building now... which I’ll be honest and say surprised me (why I have no idea). This is great, but I did exercise to deal with some pretty appalling trauma I experienced - everything else is nice but for me, not essential.
People start way too intense, spending hours in the gym, and burn out all their enthusiasm in the first weeks or two before they realize that their efforts are unsustainable. Really, start with a plan on what do to, go in and do it. If it's a half hour that's perfectly fine. My sessions, depending on the day, last anywhere from half an hour to 3 based upon my mood and the workload for that particular session - but you gotta keep the mandatory work to a reasonable amount - everything else should be treated as icing on the fitness cake.
I'm sure to go with the 11 kg there has been significant body composition changes to make it count for more as well.
Yet I'll walk to anywhere within a half an hour's walk. I'll do that daily. Grocery store? walk. I'll go longer at times. I'll take the stairs. I'll go out hiking and walking to see something or do something.
Unfortunately, if I have nothing to see or do - no work or lack the means to do something - I rarely do these things. These have generally been the times when my mental health is worst as well (though that trend has changed the last few years). It makes me despise these sorts of reports.
For me, it just took having the self-control to commit to an exercise regime. Eventually it became easier because I track my exercise and having a break in it (even if I am traveling or on vacation) feels really bad.
I doubt it would work for everyone, but I think it was necessary for me because I live in a city and even if I walked everywhere (which I do), I would never get enough exercise to offset 8-hour days of sitting at a computer desk writing software.
Also sometimes when I've spent time indoors on the PC/internet I realize that sitting outside with a book would have been better.
I s'pose that access to nearby walking routes and some sort of garden can be a big help here and I'm lucky in that respect.