Actually, It's Doesn't have to Hurt So Bad...
No pain, no gain.... right? WRONG! Believe it or not, exercise is NOT supposed to hurt. Now I'm not saying that working out should tickle, because if it does, you DEFINITELY aren't doing something right! Buuuuutttt, I AM saying that there should NOT be pain involved.
Now, having said that, there IS a difference between pain and discomfort. Pain hurts! Period. When you're working out and you have a sharp pain anywhere, stop what you're doing. Don't stop working out, just stop what you're doing that is associated with the pain. Personally, I've experienced this with running. When I run, I start getting pain in my shins. Afterward, my hips HURT really bad. There is so much physical pain associated with running that for me, this tells me that running is probably not the best exercise for me.
On the other hand, when I get a really good walk in, I'm VERY uncomfortable. My heart pounds, my muscles stretch and get sore. By the time I'm done, I'm sore and stick a fork in my muscles, they're DONE! However, there's no pain involved. Discomfort? ABSOLUTELY! Pain? Absolutely NOT! I think it's important to make the distinction between pain and discomfort. I've seen people continue on through pain (not discomfort), only to have to have something iced, rested or at worst....replaced. By their very nature, aren't workouts supposed to be healthful and good for you? Yes? Then it defeats the purpose when we're working out to our detriment...to our "unhealth", if you will. Think of it this way, you're not giving up anything when you modify your workouts so that you don't hurt. But, if you don't modify and continue on exercising in pain, you risk giving up weeks or months of regular workouts. That's not something any of us want!