Runner runs during the 3M Half Marathon with the UT Tower in the background. Text on design reads When Should You Start Training for a Half Marathon. Learn more at

How Far in Advance You Should Start Training

We’re here to help if you’re not sure when you should start training for your half

Congratulations on deciding to train for your first half marathon. Or congrats on returning for another 13.1 miles in pursuit of your PR. Either way, you should start training at some point. But what’s the optimal training timeframe for your goals? Reaching your goals requires dedication and a high level of discipline. Before you begin, take into account your current fitness level, running history, and goals. 

Give yourself enough time to train for your half marathon.

Every runner is unique with different skills, abilities, and training needs. Make sure you give yourself plenty of time to prepare, but not too much that you experience runner burnout. Our advice will get you going and provide information on when you should start training.

When you should start training

Most half marathon training plans are 12 to 18 weeks long. If you can comfortably run three miles without stopping and you’re 12 to 18 weeks away from race day, you should start training. At first, try to run 3-4 days a week. As you progress, bump it to 4-5 days a week. This is where you build your base and introduce your body to what you’re about to ask it to do. As you build your endurance and stamina, slowly increase the mileage of your runs.

Add cross-training for 1 or 2 days per week to reduce injury chances and strengthen your body. Swimming, cycling, elliptical training, and yoga are excellent cross-training methods. Don’t forget to rest when your plan calls for a rest day. And listen to your body! If it’s telling you to take a break or pull things back a bit, then do it. You’d rather miss 1-2 runs or workouts than get injured and miss 1-2 months. Skipping rest days is a simple training mistake all runners should avoid.

Build mileage slow and steady

The right amount of training will help you achieve your goals.

If you’re a first-time runner following a longer plan, allow for the first 10 weeks to build up your mileage safely. In a 10-week training program, gradually build your mileage from about 15 to 30 miles. The idea is to increase your mileage by 10 percent every week for injury prevention and optimal improvement. The trick is to gradually introduce your body to more miles so that it gets stronger over time.

Introduce a healthy diet during training

Whatever plan you choose to follow, pair it with eating healthy and hydrating properly. How healthy your diet can be is completely up to you, just like when you should start training. But just like proper training and slowly increasing your mileage, a healthy diet will make things that much easier. You have to give your body the fuel it needs to run the miles you want it to run. And you have to hydrate effectively and replace the electrolytes you’ve lost during training. Get started with these 9 healthy and easy-to-make breakfasts.

There are numerous half marathon training plans that you can choose. Every runner is different, but it’s important to remember the newer you are to running, the earlier you should start training. Remember to include a wide variety of runs, add cross-training, and give your body the rest and recovery it needs.