From the thread I want to run a half marathon, advice please!:
The main thing that you need for a starter is some running mileage. You can start easy, running just a mile at a time, or even less. You can them ramp up the mileage per run, but slowly: if you are starting off with 1-mile runs, then you should get comfortable at that distance for at least a couple weeks before you move up to 1.5 or 2 miles per run. And you don’t need a run every day: every other day is plenty, and even just two or three runs a week is good enough if your goal is finishing (as opposed to speed, which requires a little more work).
When your mileage per run reaches about 4 miles, then you can differentiate your runs between long runs and short runs. You need a good long run, at your top mileage, about once a week (although taking a week off from a long run now and then is not only okay, it is a good idea). Your other runs can cover a shorter distance. For example, you can run a 3-mile run two or three days a week, and a long run–whose distance you gradually increase over time–on the weekend.
You should also start running in some fun runs and road races, just in order to get a feel for running a race as opposed to a training run. When your long runs are about 2 miles, you can probably finish a 5K (3.1 mile) fun run. When your long runs are about 4 miles, you can probably finish a 10K (6.2 mile) road race. You need not run a road race as an actual “race”: think of it as just another training run, with a crowd training with you and organized aid stations along the route. But before you run the half-marathon, you should get a little experience with road racing so that you can develop some good racing habits like running in a crowd, pacing yourself properly (since running in a crowd can easily inspire an overly enthusiastic starting pace, which you quickly regret after the first couple miles), and taking advantage of aid stations. And crossing the finish line in front of a cheering crowd, no matter how fast you finish, is a great inspiration.
Speaking of running in a crowd, I highly recommend training regularly–not necessarily all the time, but at least on your long runs–with friends or an organized group. Your running buddies will motivate you to get out there and run on days when, alone, you might not. They will make the experience more enjoyable and make the miles pass more quickly. And you can learn from each other about running strategy and technique as you each develop your own style, experience, and knowledge base.
A healthy diet is as important for running as it is for life, but a particular diet for running is not critical until the few days leading up to the half-marathon, when loading carbohydrates is the traditional approach (which is why most marathoners eat a pasta dinner on the night before the race). There are many theories about what foods are most conducive to good running and good racing, so I won’t go into them here. Any good running guide or magazine will cover this topic.
Good shoes are also critical. Again, any good running guide will cover this topic and tell you in general what you should be looking for, and Runner’s World magazine publishes two or three annual shoe issues that cover and rate the current market. I recommend visiting a local running store–not just a general shoe store or sporting-goods shop–for advice from the resident specialist about running shoes.
Finally, I highly recommend investing in some literature that will educate you and guide your training. There are many good books about beginning a distance-running program, including–[ul][li]The Courage to Start: A Guide to Running for Your Life by John “The Penguin” Bingham[/li][li]Marathoning for Mortals by John Bingham[/li][li]No Need for Speed: A Beginner’s Guide to the Joy of Running by John Bingham[/li][li]Marathoning 101- How To Finish Your First Marathon by Scott Demaree and Eric Steele[/li][li]How to Run Your First Marathon by Andy Friedberg[/li][li]Marathon: You Can Do It! by Jeff Galloway[/li][li]First Marathons by Gail Waesche Kislevitz[/li][li]The Spirit of the Marathon: What to Expect in Your First Marathon, and How to Run Them for the Rest of Your Life by Gail Waesche Kislevitz[/li][li]The Non-Runner’s Marathon Trainer by David A. Whitsett, Tanjala Mabon Kole, and Forrest A. Dolgener [/li][/ul]Don’t worry that these books are sometimes about marathoning as opposed to half-marathoning: the same principles apply. I especially recommend the books by John “The Penguin” Bingham, which emphasize running as an exercise in enjoyment and health, rather than as a competitive sport. I also recommend a subscription to Runner’s World, a monthly periodical that contains invaluable advice about diet, shoes and other running apparel, running in cold and hot weather, and upcoming races in your area.
Good luck!