I'm relatively new to running. I ran consistently for Rugby during the spring, but I took a few weeks off. I want to get back into it, but running has always been so painful, even before I started habitually running. My lungs hurt and it hurts to breath. I feel as if my legs can go forever but my lungs just aren't keeping up. There's a definite sharp pain when I breath and it turns into more of a gasp than a normal labored breath.

I rollerblade at least 15m/trip twice a week and I bike at least 30mi/trip three times a week. Even then, my legs start to get tired toward the end, never my lungs or have breathing problems.

Is this a medical problem or a problem that will go away as I run more?