Training for a half marathon takes 6 to 14 weeks, depending on your current fitness level, and involves a mix of easy runs, speed work, long runs, and rest days. The 13.1-mile distance is achievable for most healthy adults willing to follow a structured plan, but the key is building mileage gradually while giving your body time to adapt.
How Long Your Training Should Take
Most half marathon plans run 14 weeks, which gives beginners enough time to build endurance safely while letting more experienced runners sharpen their fitness. If you can already run 3 to 4 miles comfortably, a 10- to 12-week plan may be enough. If you’re starting from scratch or mostly walking, give yourself the full 14 weeks or more, with a few weeks of base-building beforehand where you simply get used to running three or four times a week.
A typical week includes three to four runs (one long, one speed-focused, one or two easy runs), one or two cross-training days, and at least one full rest day. The long run is the centerpiece of your week, and everything else supports it.
The Four Types of Runs You’ll Do
Long Runs
Your weekly long run builds the endurance you need to cover 13.1 miles. It should be done at a comfortable, conversational pace. Most plans peak at 10 to 12 miles for the longest run before tapering down in the final weeks. Long runs strengthen your heart, improve muscular endurance, and train your body to burn fat as fuel once its stored carbohydrates start running low. Do only one per week, and increase the distance every one to two weeks.
Easy Runs
These make up the bulk of your weekly mileage. Easy runs should feel genuinely easy. You should be able to hold a full conversation without gasping. They build aerobic fitness, promote recovery between harder sessions, and keep your weekly volume up without overtaxing your body. Most runners underestimate how slow these should be.
Tempo Runs
A tempo run is a “comfortably hard” effort, roughly 25 to 30 seconds per mile slower than the pace you could hold for a 5K race. The purpose is to raise the threshold at which your muscles fatigue, so you can sustain a faster pace for longer. A typical tempo session might be a 10-minute warmup, 20 to 30 minutes at tempo pace, and a 10-minute cooldown. These runs teach you what race-day effort feels like.
Interval Runs
Intervals alternate between short bursts of hard running and recovery periods of jogging or walking. A simple example: one minute hard, two minutes easy, repeated six to eight times. The hard portions should feel genuinely challenging. Intervals improve your running efficiency and your ability to hold higher speeds. They’re uncomfortable by design, but they’re also the sessions that make your other runs feel easier over time.
Building Mileage Without Getting Hurt
You’ve probably heard the “10 percent rule,” which says you should never increase weekly mileage by more than 10 percent. It sounds precise, but research doesn’t actually support it. A 2008 study from the University of Groningen split 532 runners into two groups: one increased mileage by 10 percent per week, the other by 50 percent. Injury rates were nearly identical, around 20 percent in both groups. A separate study of novice runners found that the uninjured group averaged 22 percent weekly increases, more than double the rule’s recommendation.
That doesn’t mean you should recklessly pile on miles. What matters more than any single percentage is your overall training load, the amount of rest between hard efforts, and whether you’re doing strength work and cross-training to support your running. Listen to your body. Sharp pain, pain that worsens as you run, or pain that changes your stride are all signals to back off. Mild soreness that fades during a warmup is normal.
Strength Training and Cross-Training
Running alone isn’t enough to prepare your body for 13.1 miles. Two strength sessions per week, even 20 to 30 minutes each, make a meaningful difference in injury prevention and running economy. Focus on your core (planks, side planks, Russian twists), your legs (squats, lunges, box step-ups, wall sits), and your glutes and hips, which stabilize your pelvis with every stride. A strong core prevents your form from falling apart in the later miles when fatigue sets in.
Cross-training gives your cardiovascular system a workout while sparing your joints from the repetitive impact of running. Swimming is one of the best options because it’s completely non-weight-bearing, providing solid cardio while giving your legs a break. Cycling works the same major leg muscles as running without the pounding. The elliptical closely mimics running mechanics with less stress on your body. Even a brisk 30-minute walk counts as active recovery and promotes blood flow to sore muscles. One or two cross-training days per week is typical.
How to Find Your Race Pace
Half marathon races are best run near your lactate threshold, the fastest pace your aerobic system can sustain without waste products building up faster than your body can clear them. Go faster than this and you’ll hit a wall well before mile 13.
To find a realistic goal pace, use your mid-distance training runs (4 to 8 miles) as testing grounds. Start 10 to 15 seconds per mile slower than your target, run the middle miles at goal pace, and finish the last mile 5 to 15 seconds faster. If you’re targeting a 2-hour finish, for example, you need to average about 9:09 per mile. A sample practice session: run miles 1 and 2 at 9:24, miles 3 through 7 at 9:09, and mile 8 at 8:55.
On race day, start 5 to 10 seconds per mile slower than your goal pace. The adrenaline of race morning makes almost everyone go out too fast, and the cost shows up around mile 9 or 10. Running the first few miles slightly conservative gives you a reserve to draw on in the second half. If you feel strong with 2 to 3 miles left, that’s when you pick up the pace.
Fueling Before and During the Race
For any run lasting longer than 60 minutes, your body needs fuel beyond what it has stored. Glycogen, the carbohydrate stored in your muscles and liver, starts running low after about 60 to 90 minutes of steady running, and when it’s gone, you’ll feel it: heavy legs, foggy thinking, and a pace that suddenly feels impossible.
Aim for 30 to 60 grams of carbohydrates per hour during the race, starting around the 45-minute mark to give your body time to absorb it. That’s roughly one energy gel every 30 to 45 minutes, depending on the product. Hydrate with water throughout, and add electrolytes if conditions are hot or humid. Fueling guidelines are based on time, not distance, so slower runners actually need more total fuel than faster ones covering the same course.
Practice your fueling strategy on long training runs. Your stomach needs to adapt to taking in food while running. The energy gels, chews, or sports drinks you plan to use on race day should be tested multiple times in training so there are no surprises.
The Taper: Why Less Becomes More
In the final two weeks before race day, you’ll reduce your training volume significantly. This phase, called the taper, is where your fitness actually peaks. A meta-analysis published in PLOS One found that endurance athletes performed best after an 8- to 14-day taper in which training volume dropped by 40 to 60 percent while intensity and frequency stayed roughly the same.
During the taper, your body undergoes real physiological changes. Blood volume increases. Oxygen-carrying capacity improves. Stress hormones drop while muscle-repairing hormones rise. Markers of muscle damage decrease. Your body essentially clears the accumulated fatigue of training and converts all that hard work into race-ready fitness. The taper will feel strange. You’ll feel restless, maybe even sluggish on short runs. That’s normal and not a sign of lost fitness.
Recovery Between Runs
What you do between runs matters almost as much as the runs themselves. Sleep is the single most powerful recovery tool. It’s when your body rebuilds damaged muscle fibers and consolidates fitness gains. If you’re constantly tired, struggling to recover, or losing motivation, sleep is the first thing to address.
After harder runs, static stretching can help. Hold stretches like toe touches, quad stretches, and calf stretches for 10 to 30 seconds each. The day after a tough session, gentle movement helps more than sitting still: a casual 20- to 30-minute walk, light yoga, or easy cycling promotes blood flow and speeds recovery.
Foam rolling is another effective tool. Rolling out your calves, quads, and lower back helps release muscle tension and reduce soreness. It should feel uncomfortable but not painful. If it hurts, you’re pressing too hard. Roll evenly across the belly of the muscle rather than grinding into tendons or bony areas.
Your Shoes Matter More Than You Think
Running shoes lose their cushioning and structural support over time, and worn-out shoes are a common contributor to nagging aches. Most shoes last 300 to 500 miles, with 400 being a good average. If you’re running 20 to 25 miles per week during peak training, that means a pair of shoes could wear out within a single training cycle. Track your mileage, and if you notice new aches in your knees, shins, or feet, check your shoes first. Breaking in a fresh pair a few weeks before race day, rather than the day of, gives your feet time to adjust.