First Marathon How long does it take to train for a marathon?

Why a marathon takes 16 to 20 weeks

In 1993, Oprah Winfrey started training with Bob Greene, an exercise physiologist. In their first session, they walked about 2½ miles at an easy pace. Walking turned into walk-jogging, and that August she ran a half marathon in San Diego in 2:16. By the summer of 1994 she was running up to 50 miles a week, with longer runs on weekends. That fall she finished the Marine Corps Marathon, her first, in a very respectable 4:29:15. Her finish gave runners everywhere a new goal: "Beat Oprah." "She worked as hard as any athlete I've seen," Greene said.

Her path took well over a year: walking, then a half, then the full. Most first marathons follow that shape, from different starting points.

Most of a marathon plan is one job: growing your long run from about 8 miles to about 20. That's 12 more miles, and you can't add them all at once. Lots of running injuries start with a single run that's much longer than anything you've done in the past month. So a good plan adds about a mile a week, and every few weeks it gives you a lighter week so your body can catch up. Add the final weeks of cutting back before race day, and you land at 16 to 20 weeks.

Your body sets the pace, too. Your heart and lungs adapt in a few weeks, but tendons take a couple of months and bones longer still. The extra weeks in an 18- or 20-week plan aren't wasted, either. They're room for the cold, the work trip, and the sore week that every training block seems to hold.

And if you're coming from zero, run a half first. Among first-time marathoners in one study, those who'd raced a half beforehand were less likely to get hurt in training.

Is 12 weeks enough to train for a marathon?

A runner once wrote to coach Hal Higdon, whose Novice 1 plan is in the list above. They'd finished a marathon in December, then dropped to about one run a week. Now another marathon was less than 6 weeks off, and they wanted to jump back in at week 12 of his plan. Higdon pointed out that would leave only 3 weeks of real training before the cutback began: "Not a great recipe for success," he wrote. If they hadn't paid for it yet, he suggested, a marathon in May or June would be a better choice.

That's good news, really. A later race is a real option, and often the smarter one.

Is 12 weeks enough? It depends on where you start. If you already run 25 to 30 miles a week and your long runs reach 12 to 14 miles, yes. Pete Pfitzinger's 12-week plans assume exactly that, so most of the long-run building is done before week 1. If you're starting from about 14 miles a week and an 8-mile long run, 12 weeks is tight. Take out the lighter weeks and the cutback at the end, and your long run would have to grow much faster, by 2 miles at a time in some weeks, the kind of jump that leads to injuries.

Pick a later race if any of these sound like you: your longest run lately is under 8 miles, you run fewer than 3 days a week, you're coming back from an injury, or your race is under 12 weeks away and you're starting near zero. There's always another marathon.

What a marathon training week looks like: runs, strength, and food

Shalane Flanagan won the 2017 New York City Marathon. Back in college, she told CBS News, "we were eating everything low fat," and "little did we know that we were just eating more sugar and processed foods." She changed how she ate, and later wrote cookbooks about it. "I don't think I'd be sitting here, talking to you and running at a high level if it weren't for the fact that I changed my diet."

A first-marathon week has a simple shape. Three or four runs, nearly all of them easy, slow enough to chat the whole way. One long run on the weekend, which does most of the work. A strength session or two in between, because strength work does more to prevent injuries than stretching does. Three days of running is enough to finish a marathon. Every Buena Vida first-marathon plan comes in a 3-day version for that reason.

Food is the part that changes most from a half. A 20-mile long run burns about 2,000 calories for a 150-pound runner, while a rest day burns almost nothing extra. Eat the same every day and you'll be running on empty on the weekend and overfed midweek. Eating to match your training is what lets the training work: more carbs around your long run, and normal meals on rest days.

Hoping to lose weight along the way? You can, gently. Keep the deficit small, about half a percent to one percent of your weight a week, and keep your long-run days fully fueled. Skimping on carbs makes hard training harder, and the long run is the one your whole plan is built around.

What to eat while you train for a marathon

Allie Kieffer finished fifth at the 2017 New York City Marathon in 2:29:39, an unsponsored 30-year-old. Five years earlier, she'd had a stress fracture after a stretch of trying to drop weight. By 2018 she was fueling every workout well, Sports Illustrated reported. "I don't think you [can] stay healthy and be consistent enough to run for a long period of time if you're starving yourself," she told the magazine.

Most of your marathon eating happens at ordinary meals in ordinary weeks, and that's where the training pays off. Three habits do most of it.

Eat enough on the days you run. Long-run days need the most food, and harder days need more than easy ones. Rest days are normal eating days, not days to make up for anything. Underfueling for weeks blunts what your training builds, so don't save calories now.

Refill after you run. Runners need more carbs and protein than people who don't train. After a long run, eat a real meal with both: the carbs refill your legs for the next run, and the protein helps repair them. Spread protein across meals every 3 to 4 hours, not one big dinner.

Know the signs you're running low. Always tired, legs that never feel fresh, catching every cold, sleeping badly, feeling cranky, and runs that feel harder while your paces stall. Those are the everyday versions of what the IOC lists when athletes under-eat for long stretches. Over months, too little food undermines your bones and raises the risk of stress injuries, the kind Kieffer had. Notice a few? Look at your plate before your plan.

The long run: how far and how slow

Jeff Galloway ran the 10,000 meters at the 1972 Olympics and became famous for his run-walk method. At the Houston Marathon in 1980, he walked through every water station and finished in 2:16:35, faster than any marathon he'd run without walking. "I've been using them ever since," he said of his walk breaks.

The lesson holds at any pace: your long run is about time on your feet, not speed. Run it slower than feels right, at a pace where you can talk in full sentences, and take walk breaks without apology.

Your longest training run will be about 20 miles, not 26.2. That's by design. Marathoners who run longer long runs tend to finish faster, and 20 miles is where most first-timer plans top out, Buena Vida's and Higdon's Novice 1 included. Then cutting back in the final weeks leaves you fresh, and race-day energy carries you the rest of the way.

Treat every long run past 2 hours as a dress rehearsal: race shoes, race socks, race breakfast, and race gels. Find out what rubs at mile 14 so you don't find out at mile 22.

How you’ll know your training is working

Researcher Barry Smyth combed through more than 4 million race records from 270 races to see who hits the wall, slowing sharply late in the race. One pattern stood out: runners were more likely to hit it in the years just before their best-ever time, when they were chasing a big goal and taking more risks with their pace.

The lesson for a first marathon: let your training set your race pace, not your hopes. The pace you can hold on a comfortable 18-miler tells you far more than the pace you'd like to run.

The record cheers you on, too. Around week 8, compare an easy run from week 1. Same pace, lower heart rate? That's your fitness showing up, and an Apple Watch is accurate enough to see it.

And it catches trouble: a long run that jumped too far, a week where you ran more and ate less, a pair of shoes quietly piling up miles. Those are easy to miss when your runs live in one app, your food in another, and your plan on the fridge.

Race day

In 1967, a 20-year-old named Kathrine Switzer ran the Boston Marathon wearing bib 261, the first woman to officially register and run it. Two miles in, she was told to get out of the race. She kept going and finished in about 4 hours and 20 minutes. She later put the day you're training for into one line: "If you are losing faith in human nature, go out and watch a marathon."

On race day, you'll see what she meant.

Your last few weeks get lighter on purpose, and running less before the race, while keeping a little speed, helps you race better. Keep eating normally through them. On the morning, eat the breakfast you rehearsed, start slower than you want to, and save the brave miles for the last 6.

You don't need to be fast. You need the weeks, the food to fuel them, and a little patience. You've already started.