21.0975 kilometers – the half marathon is the perfect distance for many runners. Long enough to be a true endurance achievement that deserves respect. Short enough to be achievable without months of marathon training and its associated demands. It's the distance where running becomes a journey – no longer a sprint, not yet ultra-endurance.

The half marathon has experienced a tremendous surge in popularity in recent years. The reasons are understandable: it offers the prestige of a 'marathon distance' (at least in name), but requires significantly less training. Recovery time is shorter, the risk of injury is lower, and you can run several half marathons per year without overtaxing your body.

For many runners, the half marathon is the ultimate goal – and that's perfectly legitimate. You don't have to run a full marathon to be a 'real' runner. The 21 kilometers are a challenge that brings deep satisfaction when you conquer it.

What can you expect from this guide?

This guide is for runners who can already confidently run 10k and are ready for the next big step. You'll learn how to structure your training, how to balance pace and endurance, what nutrition means at this distance, and how to optimize your race day.

The jump from 10k to a half marathon is significant – you're doubling the distance. This doesn't require twice the training, but it does require smarter training, better recovery, and more respect for the distance. Let's walk this path together.

Before you start training for a half marathon, you should have a solid foundation – both physically and in your understanding of running.

Where should you stand?

Ideally: You've been running regularly for at least 6-12 months. You can run 10 km without collapsing at the end. You already train 3-4 times a week, at least 25-30 km weekly. You've already completed one or more 10 km races. No acute injuries or chronic problems. If you're not yet confident at 10 km, work on that first. Jumping directly from 5 km to a half marathon is too big and almost inevitably leads to injury or frustration.

The training philosophy

Half-marathon training is based on three pillars: Building endurance: The long run gets longer – from 10 km to 18-20 km. This is the core of the training. Developing a specific pace: You learn to maintain your half-marathon pace – faster than a marathon, but slower than a 10 km run. Respecting recovery: With higher volume, recovery becomes critical. Without it, the body will collapse.

The 80/20 rule (still)

The same principle applies to half-marathon training: 80% of the volume should be at low intensity (easy), 20% at high intensity (tempo runs, intervals). Specifically, this means: your long run is easy. Most of your shorter runs are easy. Only 1-2 sessions per week are fast.

Timeframe and volume

Starting from a solid 10k base, a typical training program takes 12-16 weeks. Weekly mileage during the peak phase is 40-55 km for most recreational runners. The longest training run is 18-20 km (approximately 85-95% of the race distance). Some plans go higher, but for your first half marathon, more isn't necessary – the race itself provides adrenaline and tapering effects that compensate for the missing mileage.

The weekly long run is the most important session in half-marathon training. This is where you build the endurance that will carry you through 21 km.

Why the long run is so important

The long run trains: Aerobic capacity – your body learns to use fat more efficiently as fuel. Muscular endurance – your legs adapt to longer periods of exertion. Mental strength – you learn to cope with discomfort and keep going. Glycogen management – ​​your body learns to conserve limited carbohydrate stores. No other form of training replaces the long run. You can't run 5 x 6 km and think that's the same as 1 x 20 km – the intensity is fundamentally different.

How long should the long run be?

Goal for your first half marathon: At least one run of 18-20 km before the race. Training plan: Start with your current longest distance (probably 10-12 km) and increase by 2-3 km every two weeks. Don't increase every week – include a reduction week every three to four weeks. Example plan: Week 1: 12 km, Week 2: 14 km, Week 3: 12 km (recovery), Week 4: 16 km, and so on.

Pace during the long run

Relax! This cannot be stressed enough. Your long run should feel like a comfortable conversational pace. A good guideline is 60-90 seconds per kilometer slower than your half-marathon race pace. If you normally run a half marathon at 5:30 min/km, your long run should be at 6:30-7:00 min/km. Why so slow? Because the goal isn't speed, but time on your feet. The aerobic training stimulus at 6:30 is almost the same as at 5:30 – but the stress on muscles, tendons, and joints is much lower.

Exceptions: Progression long runs

In the later stages of training, you can occasionally do 'progressive long runs': the last 20-30% of the run at race pace or faster. For example: 16 km total, the first 10 km easy, the last 6 km at half-marathon pace. This simulates the challenge of maintaining pace at the end of a long run.

Besides endurance, you also need speed. The right pace training makes the difference between 'finishing' and 'finishing with a good time'.

Threshold runs (tempo runs)

The most important tempo element for a half marathon. You run for 20-40 minutes at a pace that is 'comfortably hard' – strenuous, but sustainable. Intensity: Roughly your half marathon pace or slightly faster. You should only be able to speak in short sentences. Effect: Trains the lactate threshold – the ability to maintain a demanding pace for an extended period. This is exactly what you need for 21 km. Frequency: Once a week during the main training phase.

Interval training

Short, fast intervals with breaks. Faster than race pace. Examples for half-marathon preparation: 5-6 x 1000m at 10k pace with 2-3 minute breaks. 4 x 1600m (1 mile) with 3 minute breaks. 8-10 x 400m fast with 90-second breaks. Effect: Improves VO2max, running economy, and speed. Makes you more efficient. Frequency: Once a week, alternating with or in addition to threshold runs.

Race pace runs

Longer intervals at your target half-marathon pace. Example: 10 km at your target half-marathon pace. Effect: You learn what the pace feels like. Your body and mind get used to it. Frequency: Every 2-3 weeks in the later stages. Can also be integrated into your long run (like this).

Strides

Short sprints (80-100m) at the end of easy runs. Build speed and running economy without fatigue. 4-6 strides after 2-3 easy runs per week.

Periodization

Not everything at once! A typical structure: Phase 1 (weeks 1-4): Focus on volume, low intensity. Only strides. Phase 2 (weeks 5-8): Introduction of threshold runs. Phase 3 (weeks 9-12): Full speed work – intervals, threshold runs, race pace. Phase 4 (weeks 13-14): Tapering – reduced volume, a few fast sessions for freshness.

Here is a framework plan for half-marathon preparation. Adaptable depending on starting level and target time.

Weeks 1-4: Building a foundation

Goal: Increase volume, acclimate the body to longer runs. Structure per week: 4-5 runs. Long run: Start at 12 km, increase to 16 km. 2-3 easy runs (6-8 km). Strides after 2 easy runs. 1 optional cross-training day. Total volume: 30-40 km/week. Week 4: Recovery week – reduce volume by 30%.

Weeks 5-8: Introduction to speed work

Goal: Initial speed work, further volume increase. Weekly structure: Long run: Increase to 18 km. 1 threshold run (20-25 minutes pace). 2 easy runs. Strides after easy runs. Total volume: 40-50 km/week. Week 8: Recovery week.

Weeks 9-12: Specific Phase

Goal: Full speed work, longest runs, race pace acclimatization. Weekly structure: Long run: 18-20 km, occasionally including the last few kilometers at race pace. 1 interval session (e.g., 5 x 1000m). 1 threshold run or race pace run. 1-2 easy runs. Total volume: 45-55 km/week. Week 11: Longest run (20 km). Week 12: Recovery week.

Weeks 13-14: Tapering

Goal: To get fresh without losing fitness. Week 13: Reduce volume by 30%. Long run (14-15 km). Last fast session midweek. Week 14: Reduce volume by 50%. Only short, easy runs. Tuesday/Wednesday: Short intervals or strides (activate legs). Thursday/Friday: Rest or very easy short run. Saturday/Sunday: Your half marathon!

flexibility

This plan is a framework. Listen to your body. If you're exhausted, take an extra rest day. If you get sick or injured, take a break. It's better to start undertrained and healthy than overtrained and injured.

Nutrition becomes a critical factor at 21 km. Your body has limited glycogen reserves – how you manage them affects your performance and well-being.

Basic nutrition during training

No dieting during the training phase. Your body needs energy for training and recovery. Carbohydrates are the primary fuel for endurance sports. Good sources include whole grains, rice, potatoes, fruit, and oats. Sufficient protein is essential for muscle repair (1.4-1.8 g/kg body weight). Include healthy fats, plenty of vegetables, and adequate fluid intake.

Carb loading before the competition

For a half marathon, moderate carb loading is advisable – increase your carbohydrate intake 2-3 days before the race. Don't overdo it – you want to fill your glycogen stores, not stuff yourself. Practical suggestions: More pasta, rice, bread, potatoes. Less fiber (which can cause digestive problems). Less fat (which takes longer to digest). The evening before: A familiar, carbohydrate-rich meal. No alcohol.

Breakfast on the day of the competition

Eat 2-3 hours before the start. High in carbohydrates, low in fiber and fat. Proven options: porridge/oatmeal, toast with honey or jam, banana, bagel. Only eat what you've tested in training! Race day is not the day for experimentation.

Nutrition during the run

During a half marathon – which lasts 90-150 minutes depending on the pace – energy intake becomes crucial. Glycogen stores are sufficient for approximately 90 minutes at moderate intensity. Options include: energy gels (one every 45-60 minutes), sports drinks at aid stations, and energy bars (which are more difficult to chew while running). Important: Test them during training! Not everyone's stomach tolerates gels well. Some runners experience stomach problems from them. Find out what works for you.

Hydration

Hydration is important during longer runs, especially in hot weather. Drink not too much, not too little. Drink according to your thirst – excessive drinking can lead to hyponatremia (dangerously low sodium levels). In hot weather, electrolytes (sodium) are more important than in cool conditions.

As training volume increases, so does the risk of injury. Prevention and smart recovery are crucial.

The most common half-marathon injuries

IT band syndrome: Pain on the outside of the knee. Often caused by too rapid an increase in training volume or weak hip muscles. Plantar fasciitis: Pain in the sole of the foot, especially in the morning. Caused by overuse or unsuitable shoes. Achilles tendon problems: Pain above the heel. Runner's knee (patellofemoral syndrome): Pain around the kneecap. Stress fractures: Small cracks in the bone due to overuse. Serious – if suspected, stop immediately and see a doctor.

Prevention strategies

Gradual increase: The 10% rule applies. No more than a 10% increase in volume per week. Regular recovery weeks: Reduce volume by 20-30% every 3-4 weeks. Strength training: Targeted strength training for legs, hips, and core twice a week. Strong muscles protect joints and tendons. Good footwear: Wear suitable running shoes and replace them regularly (every 500-800 km). Warm-up: Always warm up before fast sessions. Stretching/Mobility: Static stretching after running, regular mobility exercises.

regeneration

Sleep: 7-9 hours. The most important recovery measure. Nutrition: Sufficient calories, enough protein, timing after training. Active recovery: Light activity on rest days (walking, swimming, yoga). Foam roller: Regular rolling helps release tension. Massage: Occasional sports massage can help, if budget allows.

Take warning signs seriously

Dull muscle soreness after a hard workout: Normal. Sharp, stabbing pain while running: Stop. Pain that worsens with each run: Rest and see a doctor if necessary. Swelling, redness, warmth: Get medical attention. Pain that affects walking: Get medical attention. It's better to rest for a week than to suffer a month with a neglected injury.

A half marathon is long enough that strategy is crucial. With the right plan, you'll reach your full potential.

Before the competition

Know your target pace: Based on your training runs, you should know what pace is realistic. Too ambitious = you'll hit a wall. Too conservative = wasted potential. Study the course: Where are the climbs? Where are the descents? Where are the aid stations? Plan your logistics: Arrival, picking up your race packet, changing facilities, meeting point with your support team. Check the weather: Adjust your clothing accordingly.

Pacing strategy

The most common mistake: Starting too fast. The first 5 km always feel easy – fresh legs, adrenaline, crowds. But a start that's too fast will take its toll from kilometer 15 onwards. Recommended strategies: Even splits (consistent pace): All kilometers at the same pace. Requires discipline at the beginning. Negative splits: First half conservative, second half faster. Psychologically satisfying because you overtake people at the end. Practical tip: First 5 km = slightly slower than target pace (10-15 sec/km). Kilometers 5-15 = target pace. Kilometers 15-21 = whatever you can still manage.

Mental division

Thinking about 21 km at once is intimidating. Mentally break the run down: Kilometers 1-7: 'Warm-up'. Start easy, find your rhythm. Kilometers 8-14: 'Work'. Maintain your pace, stay in rhythm. Kilometers 15-18: 'The hard part'. This is where it gets tough. Hang in there. Kilometers 19-21: 'Almost there'. Give it everything you've got.

Catering during the race

Plan: At which aid stations will you drink? When will you take a gel? Don't drink at every station – that wastes time and can lead to excessive fluid intake. Recommendation: A few sips of water or sports drink every 5-7 km. 1-2 gels distributed along the course (at kilometers 8 and 15, for example). Use what you tested in training during the race.

Your big day is here. Here's a timeline to help you make it the best it can be.

The evening before

A carbohydrate-rich meal – not too late, not too much. Pack everything: race number, timing chip, shoes, clothing (including backup in case of uncertain weather), gels if planned, and petroleum jelly to prevent chafing. Go to bed early – even if you can't sleep from excitement, rest is better than Netflix.

In the morning

Get up early – at least 2-3 hours before the start. Eat a good, solid breakfast. Allow time for bathroom breaks. Arrive at the starting area in good time to avoid stress.

At the starting area

Check in your coat (if necessary). Warm up: 10-15 minutes of light jogging, dynamic stretches, a few strides. If it's cold, stay warm until just before the start (wear an old layer of clothing that you can throw away). Use the restroom one more time. Line up in the correct starting block.

The start

Don't get swept away! Start the first few kilometers deliberately slower than your target pace. The urge to run with the crowd is strong – resist it. Breathe calmly, find your rhythm.

The middle part

Kilometers 5-15 are your 'working zone'. Maintain a constant pace. Slow down briefly at aid stations to drink. Pay attention to your body's signals – but don't overinterpret them. Discomfort is normal.

second half

From kilometer 15 onwards, it gets tougher. This is where good training pays off. Mental tricks: Focus on the next kilometer, not on what's still to come. Repeat your mantra. Look for runners ahead of you and stick with them.

The final sprint

From kilometer 19 onwards, you know – it's almost over. Summon what little you still have. You can give more in the last 2 km than you think – it'll all be over soon. Cross the finish line, register your timing chip and time, celebrate!

After crossing the finish line

Keep going – don't stop immediately. Collect your medal, drink some water, eat something. Stretch if it feels good. The next 2-3 days: Active recovery, no hard training. You did it!

You completed your half marathon – a fantastic achievement! Now the question is: What's next?

Immediate regeneration

The first week after the half marathon: Rest or only very light activity (walking, swimming). Plenty of sleep. Good nutrition. Your body needs time to recover from the exertion. Even if you feel fine, there are micro-tears in your muscles and connective tissue. Weeks 2-3: Slowly resume with easy, short runs. No speed work, no long distances.

Option 1: Improve your half-marathon time

If you want to maintain your current distance and improve your speed: Increase your training volume (50-70+ km/week for ambitious runners). Intensify your tempo training. Include more long runs with speed elements. Realistic improvement: With good training, a 2-5 minute improvement over 3-6 months is possible.

Option 2: Several half marathons per year

The half marathon is a distance you can run several times a year. Two to four half marathons a year are achievable for most recreational runners. Between races: four to six weeks of training, and a recovery phase after each race. This way you can experience different routes and cities.

Option 3: Aim for a marathon

For many, the half marathon is the stepping stone to the full marathon. Keep in mind: The marathon isn't 'twice as hard' as the half marathon – it's qualitatively different. The training load is significantly higher (60-80+ km/week at its peak). Nutrition during the race becomes critical. Recovery afterward takes longer. If you're running a marathon, plan for 16-20 weeks of preparation, building on a solid half marathon foundation.

Option 4: Other challenges

Trail running: Half-marathon distance off-road, in nature. Triathlon: Add swimming and cycling (Olympic distance includes a 10 km run, ideal for experienced half-marathon runners). Ultra-light: 25-30 km distances as an introduction to longer distances.

The long-term perspective

The half marathon is a distance for life. You can run it for decades, improving your time or simply enjoying it. Stick with it, listen to your body, and enjoy the journey – the half marathon will give you many unforgettable experiences.