Second, I don't usually find the gains to be motivating. I have trouble sticking with it after a month or two.
Third, I'm not really willing to spend money on equipment or go out of my way to a gym. I'd rather not be seen.
This may or may not be useful for you, but one thing I've had very good luck with is a stationary bike (at the gym, but it's easy to get one at home) and reading. The bike is stable enough that reading isn't a problem, especially if done on a iPad/Kindle.
I get through ~5 books a month just on the bike, and I find it easier to get motivated because I have two good reasons to do it. I'm able to go fairly hard and burn ~900 kcal in an hour's session.
It should ideally be supplemented with other types of strength-building activity, but it's possible to assemble something fairly minimal there that'll reap major benefits.
It doesn't have to be this way. The best way to stick with an exercise is to find one that you enjoy. For some people that's lifting weights, or running distances. Others like biking or yoga. I play ultimate frisbee, which I find to be a lot of fun and a great exercise. I'll be the first to admit that I should do more, but chasing a piece of plastic through the air for two hours a week is a whole lot better than sitting down at home. Try seeing what sports leagues are in your area, maybe you'll find something you like.
> It doesn't have to be this way. The best way to stick with an exercise is to find one that you enjoy.
The mistake you're making is assuming that everyone enjoys at least one form of exercise, much less would prefer to do it other than something else.
My short-term analysis is, 'why would I want to be sweaty, sore and out-of-breath when I can be perfectly happy at home, doing what I want?'
My long-term analysis, of course, is that I should exercise in spite of hating every single minute I spend on it.
What i did for myself was searching for a gym where i waste the least time, found one that has a 45 minute programm and went for it. Not that this works well motivation wise, but it was the first time it did not sound like wasting to much valueable energy and time.
It's hard to overcome #2 because it takes about 2-3 months of regular, vigorous exercise to see results, if you're just out-of-shape. If you're very overweight, it'll take even longer to see much difference.
#3 really isn't much of a barrier, since you don't actually require any equipment to get in quite good shape. You certainly don't have to join a gym.
The way to overcome #1 and #2 is to develop a habit of exercising. You do lots of things in your life that are unpleasant in the short term but give you long term gains. You don't do them because of the gains, but simply because after awhile they become habit. Commuting to work, for instance. You don't consciously think about driving in to work so you can get paid in two weeks; you do it out of habit.
You can build an exercise habit slowly, by creating a set of rituals around it (e.g., putting on your workout clothes first thing in the morning, doing a short warmup, finishing with a short cooldown) and starting off slow to minimize #1. This will also minimize gains initially, but that doesn't matter much---you'll get enough gratification just by building up a string of successful completions. Keep your early sessions to 5-15 minutes. Once you've been able to do that daily for a couple of months, extend a couple of your workouts to 20 or 30 minutes. There are a ton of great, free workouts on YouTube (Yoga with Adrienne, Fitness Blender, Millionaire Hoy, and on and on) of various durations. Once you get to a point where you're working out at least 15 minutes every day, with a few 30-minute workouts a week, you will start to see results. By three months in, you should have a fairly strong habit going, and by six months it will seem like second nature.
I used a car in the states, so I get the length of time with the gains - but in a sense, it was a habit tied to other habits that are temporarily out of commission. And I didn't really realize that until your comment. I'll have to find something else to tie it to.
The truth is, other people at the gym are busy concentrating on their own workout. They don't really have any reason to be judging you. Some people are particularly helpful and will offer advice, but most won't take a second look at what you're doing.
I exercise instead when it becomes a pleasant way to accomplish something I have to do anyway. For me the trick is to find good ways to incorporate exercise into activities I'd be doing anyway.
When the weather is nice, I walk to work because there's a lovely tree-lined route and it's much more enjoyable than standing on a loud and crowded subway. If the elevator line is 15 min long, I'll walk a few flights of stairs. And of course, the subway itself plus living in a walkup means a handful of flights daily. And maybe I'll get off a stop early and walk half a mile home, stopping for groceries along the way.
But even solving that point, I still struggle with the motivation & enjoyment. The 24hr gym has got me working out more, but still not regularly.