Today marks the 121st Boston Marathon and this morning, thousands of runners will toe the start line of the 26.2-miler, the oldest annual marathon in the world. The race is known for its history but also its challenging course: It starts with several fast downhill miles—so people tend to begin too fast and find themselves tired and with aching quads by the time they hit a series of notoriously tough hills late in the course.

To race Boston takes not only hours and hours of long runs and speed work in prep but also strategic training for strong legs and good pacing. Read on for lessons learned from training for the Boston course—and tips about how you can use them to be a better runner yourself, whether or not you'll ever hoof it up Heartbreak Hill.

1. RUN IN THE RAIN. 

Getting wet while you work out sound less than pleasant? Get used to it. "Race day in Boston often presents runners with imperfect weather, like rain and cold," says Michael Meliniotis, a coach at Mile High Run Club in New York City, and an age group runner who has finished 13 marathons (including three in Boston). "To manage those conditions, you need to experience them first." That means if you have a outdoor run planned and it starts raining, don't take your miles to the treadmill; make yourself jog in bad weather now and when you encounter rain or sleet or snow later, it won't seem like such a big deal. To keep from slipping, shorten your stride a bit. And to make it a little more comfortable, make sure to wear a waterproof running jacket and hat, suggests Ali Baldassare, a Precision Running coach at Equinox in Boston. "Staying as dry as possible will reduce your chance of chafing or getting blisters, and it helps keep your core body temperature warm," she says.

2. DON'T GIVE IN TO THE WIND.

Along with occasional showers, Boston runners are also often hit with heavy spring winds. "Depending on how strong and persistent the wind is, it can sometimes feel like you're getting punched in the stomach or slapped in the face over and over again," says Baldassare. It takes a lot more effort to run into the wind than when there's no breeze, so she recommends maintaining a consistent effort level and not paying attention to your pace. And help yourself out a bit by wearing form-fitting clothing, she says: It'll cut down on some of the resistance.

Wind at your back? That can give you an awesome boost, but there's a lesson to learn with a tailwind too, says Meliniotis. Take note that it's helping you run a little faster, and if the breeze stops, don't try to keep up the same pace, he advises—as you could end up raising your effort level too much and zapping your energy too soon.

3. DON'T GO OUT TOO FAST.

Competitors in any road race tend to start speedier than they planned to because of adrenaline and the excitement of the starting line—but it's even easier to begin too fast in Boston because the first four miles are a steady descent. Keeping your pace on track is both a science and a feeling. Wear a Garmin or other watch with GPS and check in on your speed every mile or two, then adjust your pace if you need to. However, Baldassare recommends not keeping your eyes glued to your wrist but paying attention to your breath and how your body feels to judge your effort. "During a race, your target pace might feel ‘easy’ because your adrenaline has kicked in and you settle into your groove. The mistake happens when you're feeling good and you think you can do more, or run faster. Don't. Hold back and save it for when you're going to need it the most—the last few miles of your race."

4. STRENGTHEN YOUR LEGS

The early downhill section of Boston may seem like a breeze, but it actually gives legs a beating, especially your quads. In addition to practicing running downhill often, doing leg exercises like lunges can prep your quads to better handle the impact. "Strength training is crucial and such an integral part to any good running program, especially when it comes to hill running," says Baldassare. Also, focus on engaging your abs and glutes to take some of the impact off your quads and spare them from some soreness later, suggests Meliniotis. It can also help to take quick, light steps on the downhill and make sure you're not over-striding, he says; to do so, pay attention to where your feet go and try to make sure they're always landing directly under your body.

5. RUN HILLS THE RIGHT WAY

After the initial decline on the Boston course, runners hit a set of rolling hills. Your approach should vary depending on whether you're heading up or down, says Baldassare. On the uphill, she recommends leaning into the incline from your ankles and to move your arms more. "Pumping your arms parallel to your body revs up your energy," she says. Then when you crest the hill, don't put on the brakes! "Too often I see runners go into recovery mode down a hill," says Meliniotis. "Downhills are not recovery, they're an opportunity. Think about it as a roller coaster and you're gaining momentum." As far as form goes, continue to lean forward slightly so you don't land on your heels, which can hurt your knees.

6. SAVE SOME ENERGY FOR THE END OF YOUR RUN

Probably the most well known feature of the Boston course (besides the pumped-up cheer section in Wellesley) are the Newton Hills, including the infamous, dreaded Heartbreak Hill. They're fairly tough on their own but can feel downright torturous if your quads are already aching from the first two-thirds of the race. The secret of powering up tough terrain late in the game: Run some hill repeats at the end of your workouts. "It'll train your body how to efficiently use energy later on, when you're tired," says Baldassare. “The more your legs become accustomed to the energy demands of your running, the better they’ll be able to adapt and perform.”

A version of this story first ran in 2016.