Whenever you are exercising for health, it is important to remember my Rule of 80%. Use 80% effort for each technique, no more, no less.
So, if you are doing wall push-ups, don't do them until you can't even raise your arms anymore. That's 100% effort. If you get to that point at, say, 30 push-ups, then you should only be doing 20-25 push-ups during your workout.
What if you are doing stretches? The same Rule of 80% applies. Don't bend over so far while doing Vitamin H that you think your legs might buckle. That's 100%. Get to a point where you feel the stretch, but don't feel any pain, and then support your head, arms, and neck with a chair or some yoga blocks.
In fact, this Rule of 80% even applies to meditations. It's better to cut your meditation off a few minutes early, before you lose your concentration, than to just let it fizzle out on its own. So, if you can sit still and quiet for 25 minutes at most, you should meditate each day for 15-20 minutes.
If, while following the Rule of 80%, you begin to feel like this level of effort is too easy, then congratulations! You've improved your strength, or flexibility, or mental focus, and now your old 80% level is your new 70%. That means you can push a little more and go for the next step.
In terms of weight loss, the Rule of 80% effort is especially important, because it helps us avoid injuries. Many people get into the habit of thinking that if they push themselves very hard during their workout, they will lose those few extra calories that make the difference. But this is dangerous, because pushing yourself like that could result in an injury, such as a torn muscle, or a sprained ankle. If that happens, those few dozen extra calories you burned aren't going to mean much if you are stuck on the couch in a sling for the next three weeks.
Mind-over-Matter isn't all at once. It's slow and steady.