Half Marathon Training Plan

The Essential Components of Half-Marathon Training

12-Week Half Marathon Training Plan: Your Guide to 21.1 km

This 12-week schedule is designed for beginner to intermediate runners aiming to complete a half-marathon (21.1 km). The plan safely increases your weekly volume, focuses on building foundational endurance, and includes specific speed work to improve your pace and running economy.

Successful training for the 21.1 km distance relies on balancing four types of running to develop different physiological systems.

12-Week Half Marathon Training Schedule (Metric Only)

The plan is broken into three phases: Base Building, Peak Endurance, and the Taper. All long runs should be performed at a comfortable, conversational effort.

Phase 1: Base Building & Speed Development (Weeks 1-4)

The focus is on establishing consistency and introducing structured workouts to prepare the body for the coming increase in long-distance running.

Phase 2: Peak Endurance & Specificity (Weeks 5-9)

This is the core phase, where the long-run mileage increases significantly. Use your long runs to practice your race-day hydration and nutrition strategy.

Phase 3: The Taper (Weeks 10-12)

The taper is essential. You dramatically reduce mileage to allow your muscles to recover, absorb the training, and store vital energy for race day. Maintain a few short, fast strides to keep your legs sharp.

Frequently Asked Questions (FAQ) for Half Marathon Training

Addressing these top-ranking questions can help you achieve optimal training results and stay injury-free.

1. What kind of shape do I need to be in to start? (Prerequisite Fitness)

You should be able to comfortably run 5 km three times a week before starting this 12-week plan. If you cannot, focus on building a consistent 5 km base for a few weeks first. This foundation prevents injury and burnout.

2. How much time will this training take me each week? (Commitment)

During the peak phase (Weeks 5-9), you’ll typically spend 3 to 4 hours per week actively running, split across 3-4 run days. Add another 1-2 hours for cross-training or strength sessions. Consistency (getting out the door) is more important than total volume.

3. What is the difference between soreness and injury? (Injury Prevention)

Soreness is general muscle stiffness that fades within a day or two and lessens as you progress. An injury is localised, sharp, or throbbing pain that persists, sometimes worsening with movement. If you feel sharp pain, take a rest day immediately. If pain continues for more than 48 hours, seek professional advice.

4. How long should my longest long run be? (Peak Distance)

For the half-marathon, your longest run should generally peak at 16 to 20 km, as shown in the schedule. It is generally not necessary to run the full 21.1 km in training. If you can confidently run 18-20 km, the race-day adrenaline and atmosphere will carry you the rest of the way.

5. What should I eat and drink during my long runs? (Fueling Strategy)

• Hydration: Drink a small amount of water or an electrolyte drink every 15-20 minutes during runs over an hour.
• Fuel: For runs over 90 minutes, practice consuming simple carbohydrates (gels, chews, or sports drink) every 45-60 minutes. Test your race-day fuel (the specific brand and flavour) repeatedly during your long runs to train your stomach.

6. What is the ‘Taper’ and why is it important? (Race Readiness)

The taper (Weeks 10-12) is the planned reduction of training volume. It is crucial because it allows your muscles to repair damage, top up your energy stores (glycogen), and ensure you come to the starting line feeling fresh and energised, not fatigued. You don’t lose fitness during the taper—you gain recovery!

Download the plan here: 1/2 Marathon training plan