That depends what you're talking about. If you are sore for many days afterward, you've started too hard. That extended pain is one of two things: acid buildup from over-training (sore muscles) or damage (sore connective tissue, usually) due to pushing too far. If your conditioning leaves you sore until the next conditioning session, you need to back off and let your body start to adapt. As your body becomes more accustomed to the workout (builds muscle, flexibility, and endurance) the soreness will be for shorter periods. If you work out hard, though, there should always be some soreness; that shows you pushed the muscles far enough that they need to build up more/better fibers. That's what conditioning is.
Good point.
For the exercise, it shouldn't be 'pain', but you should feel sore. For conditioning, if you are just starting to condition and you do not feel pain, there is an issue. No way to really avoid it.
I didn't address the taking hits side of this. With that, part of what you're doing is teaching your body how to respond to those impacts. If we aren't used to hits, our body reacts at a fairly high level: easy bruising, lots of soreness. If we take those moderate hits on a regular basis, our body reduces its response to them and some tissues toughen: less bruising, and most of the soreness doesn't show up. This, in my opinion, is actually among the biggest advantages someone who competes in full-contact fighting gets. There are downsides to full-contact, but it is inarguable that they can wade through much more punishment, which can be a huge benefit in some self-defense situations.
So what you're trying to say is that my body haven't adapt for taking hits?
It is the only way you will do any conditioning without pain.
Are you in pain or simply uncomfortable?
No? I'm saying you should feel pain.
