Running: legs vs lungs

Now that spring has arrived here in Minnesota, I'm getting back into my running routine. With the snow & cold we get here, I always take winters off. But I'm noticing something and thinking back, it was an issue last fall too.

I'm noticing that even though I'm running the same routes, I'm getting out of breath faster than I used to. I mentioned this to a friend of mine who swims, and she had the same issue: she said it was because she got stronger. I'm wondering if that's happening to me too; my legs feel firmer/bigger than they used to. Now that's great, but I'd rather increase my distance than my speed. So how do I get my lungs to catch up to where my legs are? Anyone else have the same issue and have any ideas? Thanks in advance! :)