When I tell people that I'm a runner, I usually get the response, "Really? I hate running..." I've thought a lot about this, because people who run really love it, and people who don't usually hate it. There isn't a lot of middle ground, and the lovers are definitely outweighed by the haters. Why is there such a divide?
I think the biggest reason is that when many people start running, they do it wrong. Specifically, they go out too hard. Running is a very aerobically challenging sport; it doesn't require a great deal from your muscles, but it makes a terrific demand on your lungs and heart. And if you aren't in good shape when you take up running, that is a huge leap to make. What most people do is they choose a distance or a length of time that seems like a reasonable amount of time to run, and they go out and run at a pretty fast speed. The problem with that is for most people, this will be too much at the beginning. Five minutes into the run their lungs are burning and their heart is beating close to the red line, and they think, "this is terrible!"
And the thing is, they are right. Running that close to your maximum heart rate is painful, it can be torture. I love to run and even I feel that way when I am running that hard. But if you slow down the pace then it wont feel like that. It will be work, no doubt, but it wont be painful. And the refreshing feeling you get from the exercise, the exhilaration from going fast on your own power, and the rush of endorphins will totally outweigh the mild discomfort.
It took me a long time to learn this lesson. When I was training for the 2004 Salt Lake City Marathon, I was very disciplined but unwise: every run was a long run, and I ran it as hard as I possibly could. And because of that, as I was lacing up my shoes I would have this sinking feeling in my stomach: I knew how much pain I was about to go through. I made a lot of gains very quickly, but I flamed out hard after two months, and it was only after a long break that I was ready for the big race.
So how do you find the right pace? You can do it from heart rates, but I usually just go by feel. When you start, go out at a pace that has you breathing heavily, but just barely. You should feel like you could go much faster if you tried. At the beginning this might be very slow, and I think that is what throws people off. They have an arbitrary speed set in their mind, but that speed might be completely unrealistic at the beginning. Pick a speed that will be easy to do for 15-20 minutes. You make special aerobic gains after this much time with an elevated heart rate, so this is the best goal to have at the beginning. Gradually increase the length of your runs at this same pace, until you can run as long as you want at that easy, light pace. Then you can gradually increase the speed, and that easy exertion level will be faster and faster.
If you are a competitive runner, then you will need to have runs that reach that high intensity, where it is very hard and painful. But even for elite athletes, very few of their miles are at those levels. Take a look at this chart:
This is from Joe Friel's blog, and this is a breakdown of one of his cyclists training. It shows how much of his exercise is at different heart rate zones, Zone 1 being the easiest and Zone 6 being the hardest. Most of this athletes exercises are at a pace that would be considered "easy". Those really tough workouts definitely come around, but they are for very specific goals, so when it gets tough those athletes know exactly what they are sacrificing for.