How to Train for a Half Marathon

Learning how to train for a half marathon is simpler than the 13.1 miles (21.1 km) suggests. You build an easy base, add some speed, stretch your long run, then taper before race day. Most first-timers need 10 to 12 weeks, and runners who already cover 10K comfortably can often be ready in around 8. This guide walks you through each stage. Prefer a set schedule? Our 12-week intermediate half marathon training plan maps out every session.

• Most beginners need 10 to 12 weeks of structured training to run a half marathon.
• Three to four runs per week suit most first-timers, with at least one full rest day.
• A balanced week includes one easy run, one faster session and one long run.
• Your longest training run should reach 10 to 12 miles (16 to 19 km).
• A one-week taper at 70 to 75% of your previous week’s mileage keeps your legs fresh for race day.
• Strength work, sleep and sensible fuelling support your running as much as the miles themselves.

A little preparation makes the first few weeks much smoother. Start by checking your current fitness. If you can run for 30 minutes without stopping, you are ready to begin a half marathon block. If you cannot yet, spend three or four weeks on a 5K starter programme first, then return to this guide.

Choose your race and count back from the date. A race 12 weeks away gives most beginners comfortable room to build. A race six or seven weeks away works only if you already run regularly. Booking an event early gives your training a fixed target, which makes missed sessions harder to justify.

Running shoes deserve proper attention at this point. A half marathon block can add 200 miles or more to your legs, and worn-out shoes lose their cushioning over time. Most running shoes last roughly 300 to 500 miles, depending on your weight, running style and surfaces. Choose a pair that feels secure around your heel and has enough room for your toes to spread as your feet swell on longer runs. Many runners rotate two pairs, which also spreads the load on their legs.

Finally, build the week around your life. Pick the days that you can protect for running, and decide in advance where your long run will sit. Weekends suit most people, but an early Sunday run is just as effective as a Saturday one.

Every half marathon plan combines the same five building blocks. Understanding what each run does helps you train with purpose instead of running every session at the same effort.

Knowing these five types means you can swap sessions around when life gets busy, without losing the purpose of your training week.

The opening weeks are about consistency, not testing your fitness. Rushing into big distances is the most common reason beginners pick up injuries or lose motivation.

Begin with lower weekly mileage and add distance slowly. Aim for three or four runs per week, each covering 3 to 6 miles at an easy pace. Experienced runners who feel strong can add a fifth run, but extra mileage is optional rather than required.

Add one interval session each week. Keep it short, around 20 to 30 minutes in total, including a gentle warm-up jog at the start and a cool-down at the end. The aim is to wake up your legs, not to exhaust them.

Leave energy in reserve at the end of every run. A good rule is to finish each session feeling that you could have done a little more. Consistent, manageable runs build fitness faster than occasional exhausting ones, and they protect your motivation.

Keep a simple training log during this stage. Note the distance, how the run felt and any niggles. A log shows your progress clearly, and it helps you spot patterns if a niggle develops.

Gradual mileage increases also lower the risk of overtraining, which happens when your body receives more work than it can recover from. Early signs include heavy legs, poor sleep and a higher resting heart rate. If these appear, take an extra rest day.

After two or three weeks of regular running, your body adapts to the routine. Runs that felt tough in week one now feel manageable. This is the moment to raise the intensity rather than the mileage, and weekly distance should not jump sharply in weeks four and five.

Threshold running is the most effective tool at this stage. A simple threshold workout looks like this:

• Run 2 miles at an easy pace.
• Run 1 mile at threshold pace.
• Finish with 2 miles at an easy pace.

Repeat this session once a week and extend the threshold section gradually. Over time, the effort that once felt hard becomes your comfortable pace.

Introduce your weekend long run around the midpoint of your training. Start with 8 miles and build towards 10 miles at a conversational pace. Slow is fine here. A long run at the right pace trains your body to burn fat efficiently and spares your legs from unnecessary fatigue.

Pair the long run with a 5 to 6 mile paced run during the week. Paced running means holding a steady, slightly faster effort for the full distance. This combination develops stamina and speed at the same time.

Add short bursts of faster running into some of your regular sessions. Even four or five 20-second pick-ups at the end of an easy run teach your legs to move quickly when tired.

Once your base is secure, training becomes more specific to race day. The effort rises, but the structure of your week stays the same.

Add one hill route to your week. Run hard up a short incline, jog back down to recover, and repeat. Hill repeats strengthen your calves, quads and glutes, which helps you hold form when you tire in the final miles.

A typical week at this stage looks like this:

• An easy 5 to 6 mile run at the start of the week.
• Two threshold runs of 4 to 6 miles, with a mile of easy running to warm up and another to cool down.
• A few 30-second fast bursts within some runs, to get used to quicker running.
• A weekend long run of 10 to 12 miles at an easy pace.
• At least one rest day, with Friday working well before a weekend long run.

Your longest run should peak around two to three weeks before race day. A 12-mile run builds all the stamina you need, because race-day crowds, adrenaline and a rested body carry you through the last mile. Running the full 13.1 miles in training adds injury risk without adding fitness.

Use these weeks to practise race-day habits. Wear the shoes, socks and clothing you plan to race in, so you can spot any rubbing or irritation early. Check your forecast and dress for race conditions. A lightweight running jacket, gloves or a cap can make a big difference on a cold, wet morning, and a few test runs in different weather will show you what works.

Running builds your heart and lungs quickly, but your muscles, tendons and joints adapt more slowly. Strength training closes that gap. Two short sessions per week of 20 to 30 minutes are enough for most runners.

Focus on exercises that mirror running movements:

• Squats and lunges to strengthen your quads and glutes.
• Calf raises to protect your Achilles tendon and lower legs.
• Planks and side planks to keep your core steady as you tire.
• Single-leg balance work to improve stability on each stride.

Low-impact cross-training also helps. Cycling, swimming or rowing builds fitness without the pounding of road running, which makes these activities a useful swap on a rest day when your legs feel heavy.

Rest is part of training, not a break from it. Your body gets stronger during recovery, not during the run itself. Schedule at least one full rest day each week, and prioritise seven to eight hours of sleep where possible. A foam roller, compression wear and recovery footwear can ease tight muscles after hard sessions.

Treat pain differently from ordinary tiredness. Muscle fatigue spreads across both legs and fades within a day or two. Sharp, localised or worsening pain signals a possible injury. If a niggle lasts more than a few days, reduce your mileage and seek advice from a physiotherapist before it becomes a longer layoff.

What you eat and drink supports every session. For most runs under an hour, a balanced diet and a glass of water beforehand are enough. Longer runs need more planning.

Eat a carbohydrate-rich meal or snack one to three hours before your long run. Porridge, toast with banana or a bagel with peanut butter all work well. Choose foods you know suit your stomach.

During runs longer than 75 to 90 minutes, take on carbohydrates to keep your energy steady. Many runners aim for roughly 30 to 60 grams of carbohydrate per hour, usually from energy gels, chews or a sports drink. Start fuelling early in the run rather than waiting until you feel tired, because late fuelling rarely catches up.

Practise this on your long runs. Your stomach adapts to fuelling with training, so trying a gel for the first time on race morning invites problems. Find out which brand the race organisers provide on the course, and train with that product if possible.

Drink little and often during longer runs, and carry a handheld bottle or running vest if your route has no water stops. After each long run, eat a mix of protein and carbohydrate within an hour to kick-start recovery. A glass of milk, a recovery shake or a chicken sandwich all do the job.

A taper is a planned reduction in training before a race. The goal is to let your muscles repair while your fitness stays intact. Many first-time runners worry that cutting mileage will cost them fitness. In fact, a short taper leaves you stronger, because your legs arrive at the start line fully recovered.

Reduce your weekly mileage to around 70 to 75% of the previous week during the final seven days. Keep your usual run frequency and include some short, faster efforts, so your legs stay sharp. Cut volume, not rhythm.

Early in race week, run an easy session that includes 1 to 2 miles at your intended race pace. This helps you judge the effort and builds confidence. Follow it with a short 3 to 4 mile run in your full race kit, which confirms that nothing rubs or irritates.

Spend the final days resting, eating familiar meals and drinking plenty of water. Avoid trying new foods, new gear or new routines. Pack your race bag the night before, and include spare socks, a post-race layer and any fuel you plan to take.

Plan your journey to the start line in advance. Knowing your route, parking and start time removes avoidable stress on the morning itself. Arrive early, warm up with five minutes of easy jogging and a few dynamic stretches, then settle into your planned pace for the first mile. Starting too fast is the most common half marathon mistake, and a patient first few miles leave you strong for the last three.

A 10 to 12 week block includes some flat patches, usually around the middle weeks when the novelty has worn off and race day still feels distant. Small tactics help.

Run with a club or a friend once a week to add accountability. Choose a charity or personal goal that gives your race meaning. Break the block into three-week chunks and reward yourself at the end of each one. If a session goes badly, treat it as one data point rather than a verdict on your training. Fitness builds over weeks, not days.

Be flexible too. Illness, travel and work deadlines will disrupt some weeks. Missing a session or two does not undo your progress. Pick up where you left off, and avoid cramming missed miles into the following days.

Training for a half marathon follows a clear pattern. Build an easy base, add threshold and hill work, extend your weekend long run to 10 to 12 miles, and taper for the final week. Strength training, rest and practised fuelling protect you along the way. With 10 to 12 weeks of consistent effort, most runners can reach the start line confident and ready.

Browse running shoes, fuel and recovery gear at Runners Need to start your half marathon training with the right kit.