... there's no secret.
After a recent team workout in which she was in attendance, one of my favorite runners (we'll call her Runner X) asked me how Runner Y got "so friggin' fast". I tactfully responded "She got faster by running. A lot. Nothing too fancy - just a lot of hours on the roads and trails. No shortcuts." Of course Runner Y's improvement from a 4:20 marathon in her 2010 debut to a 3:05 by NYC in 2010 is remarkable, but her method of improvement is remarkably simple.
The innocent query was actually quite typical of one I get quite often. I think that some people want me to tell them that the secret is Zumba for Runners, or Boot Camp for Runners, only running three times a week, a nutritional supplement, or something else cutting edge, trendy or clever. The truth is that if you want to be come a better runner, your best strategy is usually Running for Runners. Don't get me wrong, I'm a big advocate of some strength training to complement an endurance program, I like an occasional yoga class, and many runners benefit from some form of cross training in lieu of running when they're injured or in need of an easy day. But for a healthy runner trying to get faster, those things need to complement - not replace - running.
Back in the day, Mark Allen - who is arguably the greatest triathlete ever - was (understandably) a big advocate of cross training. Yet even Mr. Allen hung up the bike and goggles when trying to qualify for the Olympic Marathon team. When push came to shove, he realized that the best way to become a better runner was to run more.
Many folks have looked at Runner Y's quick acension in the running world, or that of other impressive athletes, and tried to chalk it up to "good genetics". Doing so detracts from the hard work that she (and others like her) put in. (Certainly, picking the right parents is important to athletic success, but most of us have not maximized our potential). Runner X and others got better when they started running more.
Don't get me wrong. I'm not saying that there's one right or wrong way to train, nor am I trying to offend anyone who uses other methods. (I usually make it pretty clear when I'm trying to offend someone.) There's not one right or wrong goal, and some athletes respond better to different types of training. Most of us are training and racing for "fun", rather than for sponsorhip or prize money. If you enjoy classes - take them. If you break down physically, or just don't enjoy high volume - then diversify. But if your goal is to become a better runner, running is a pretty good start.