My experience is that I don't feel good after exercise at first. I have to keep it up for multiple weeks, until my body actually gets fit enough that I can pass some inner threshold of a Real Workout, and get my reward of a happy kind of exhaustion.
I'm currently out of shape and fighting to try and get myself to go exercise regularly enough that this happens again. It's not easy.
I don't hate exercising, I hate the word, I hate the connotations and my history with it. I hated being overweight and as a result hated exercising.
Your making not making excuses, your brain is just making a rational judgement about the return your getting from that exercise. It might be looking for health benefits, but your brain wants the dopamine reward from the action. You need to get something emotional satisfying with the form of exercise you are doing. So you are going to have to find something fun, challenging but more importantly a short reward for that energy you put into exercising.
I think this is an interesting part. I've absolutely never felt embarrassed working out (no matter how out of shape I am), only about not exercising.
Exercising, for me, involves something of a Stoic (capital S) mentality: discomfort sucks, but it's temporary, and you can accept or even enjoy that aspect. It'll fade into the background soon enough.
Some people like to push themselves, others want the social aspect of team activities, some need a competitive aspect. Maybe the best option is working out with a friend you'd hate to disappoint by not showing up. Figure out what you can use to push yourself, and an activity that you don't hate much. Exploit your own psychology.
1) I don't feel anything interesting during exercise. I feel vague pressure and tension in roughly the expected places for a given movement, but that's about it. I don't get the sense that my body is actually doing anything in response to that movement.
2) If I make any attempt at actual intensity instead of literally just going through the motions (which does not do much to alleviate point #1), I often end up with some weird injury that flares up over the next week or two, even when nothing seemed to go wrong. Getting "brain fog" for hours after the exercise is also pretty common.
I suspect this is something to do with a broader interoception deficit (I also have trouble gauging hunger/fullness, thirst, tiredness, illness etc.), but it's hard to find any reliable information about that sort of problem. Most sources basically just tag it as an autism spectrum symptom and don't bother actually examining it.
Don't wait until you are thirsty. Drink a mouthful of isotonic drink every 10 to 15 minutes minimum regardless of how you feel. Same for nutrition. Take a protein recovery shake immediately after you work out and then eat your meals normally. Also drink plenty of water after you exercise.
Maybe I wasn't clear about this: I don't know how to maintain a consistent intensity when exercising. I don't have any particular awareness of my heart rate or respiration rate going up unless I stop and literally count. I don't have any sense of how fatigued I am until a good 15-30 minutes after I'm done, and even then it's quite vague.
As I already tried to explain upthread (this seems to be a pattern), I have tried, and I don't know how to do those things at the same time. I can stop and count my breaths, but the sensation is so indistinct that it becomes difficult to keep track of when I'm doing anything else.
It may be that the good feeling people get after exercising only comes later, after you somehow start associating exercise with its benefits.
I decided I had to first decide whether exercise was valuable to me. If I came to the conclusion that it wasn't, then I could forget about it completely and never worry about it again. I sense that you're still not completely convinced that exercise isn't a valuable activity, so I'd suggest continuing to apply logic to this problem until you know for certain.
My first step was to list out the pros and cons. Cons, it turned out, were just a few: time, a little bit of money, and temporary discomfort. Pros were significantly more: less pain as I age, more mobility as I age, more strength in case I need to lift things or climb over something one day, increased courage that comes with having a stronger body, increased courage from facing my fear of going to the gym, increased discipline, increased persistence, defeating a part of myself that's eaten away at me for too long, etc.
By doing that, I'd decided for myself that exercise was a valuable thing for me to do. I'd encourage you to do the same thing, and see if you come to the same conclusion. Once you find your own reasons for doing something, doing that thing becomes easier. Lifting weights because of some vague idea that it's good for you is a difficult thing to maintain. Lifting weights because it's a personal exercise in courage and discipline, for example, makes it way more likely to stick.
I'd also like to offer a tip on starting to exercise: start small. All my failed attempts at starting a gym routine in the past happened because I tried to make too big of a change too quickly. Instead of starting a whole new diet and exercise routine, I'd recommend finding ONE exercise that you'd like to get better at, and attempting to increase your numbers in that exercise over time. That's all. For me, it was the pullup. For you, it might be the pushup, or the squat, or the overhead press. It just needs to be something that you can increase over time. I started off being able to do just one pullup, and increased that number significantly over the next couple of months (here's another tip for increasing your reps of an exercise: google 'greasing the groove'). The great part of this approach is that the opportunity cost is extremely small — it takes maybe 10 minutes out of every day. So if you do decide that you want to try exercising again, I'd encourage you to forget complicated routines or schedules for now. Start as small as possible with a single activity, and focus on increasing the number over time.
Everyone that talks about the good feeling you get afterwards either has different physiology, feels pain to a lower degree, or just has a better willpower + long term view. Regardless, such advice just feels like a dodge or an attack. Meanwhile, while my brain KNOWS healthy is better, the consequences just don't FEEL real, so it is far easier to procrastinate. All of which makes activity MORE painful, MORE uncomfortable, and MORE embarrassing (because I'm more out of shape), so it's the opposite of a virtuous cycle.
My issues today are a combination of time (in addition to disliking the activity, I'm disliking the opportunity cost), discomfort, fear, and boredom (if I have nothing to focus on all I end up focusing on is my discomfort. If I have something to focus on, I'll instinctively stop doing things that make it harder to focus, such as movement, which means I have to start focusing on the bad parts again). I know (again, from experience) that I can feel better with more exercise eventually - but it takes weeks at a minimum, involves a lot of discomfort, is easily lost, and has not yet been a strong feeling (though I've never had any activity I maintained for more than 3 months, and that rarely).
All of which sounds like excuses...and are. But they are also real obstacles I need to find a work around for, because willpower and logic alone have clearly not sufficed.