10K to Half Marathon Training Plan

So you’ve completed your first 10K or you are simply bored of 10Ks and want to push yourself on to the next big race – the half marathon. While a 10K (6.2 miles) is no small running distance it doesn’t quite live up to more than double the distance of the half marathon. With proper training, just like transitioning from the 5K to the 10K, you should be able to run a half marathon somewhere between 6 and 8 weeks of training after a 10K.

10K vs Half Marathon Distance

Difference in distance


A 10K is 6.2 miles long. Most runners can finish a 10K somewhere between 45 minutes and 1 hour and 20 minutes. Some of the elite runners can now run 10Ks in as little as 30-minutes (less than 5 minutes per mile).

Half Marathon

A half marathon is 13.1 miles long (21 kilometers (21K)), and most average runners can finish a half marathon somewhere between 2 hours (faster runners) and 2 hours and 45 minutes (slower runners). Many of the above average and elite runners can run sub 2 hours, some of them near the 1 hour and 30-minute mark.

Difference in training


Most runners that have been running for 6 months or more can normally train for a 10K within about 3-5 weeks. While most brand new runners will take somewhere between 6 and 10 weeks to fully train for their 10K. The main factors between different training times come down to the runner’s current fitness level. Some runners need to take more time to build their running legs, while other runners can do it in half the time.

Half Marathon

Just like when you trained for a 10K, you slowly had to increase your weekly running volume by about 1 mile a week (1.6 km a week) past the distance of a 5K. The same principles hold true here, however, you will be pushing your total weekly running volume much higher than when training for a 10K. Most runners can train for a half marathon somewhere between 8 and 12 weeks. Brand new runners will need more time to train so they should be able to train for a half marathon somewhere between 14 weeks and 18 weeks.

Related: 102 Half Marathon Tips For Beginners!

Difference in fueling


You don’t need to use any type of on-course fueling during your race. Your body’s built-up glycogen stores from your weeks of training should be adequate for you to reach the finish line without requiring supplemental fuel.  Plus, your morning meal before your 10K race will help with any fueling inadequacies you think you might run into when running a 10K race.

Half Marathon

While some of the most elite and way above average runners will tell you that they don’t use any on-course fuels to finish a half marathon race. The other 90% of runners use some type of on-course fuel in the form of gels, bars, candy, liquids, foods, etc. The longer you stay on the half marathon race course (the slower runners), your body will need extra fuel on the racecourse. The most popular fuel for runners is the energy gel (my review) which is easily consumed with water. Another popular form of on-course fuel is sports drinks.

Moving from a 10K to a Half Marathon

How long should it take to transition from a 10K to a Half Marathon

The average runner should be able to race a half marathon about 6-7 weeks after a 10K race. Some newer runners will need to take longer to train for the half marathon (8 plus weeks), especially if they pulled off a hail-mary 10K (basically didn’t train and showed up to a 10K race).

Expect to be running more weekly miles

In order to get across the finish line in as little pain as possible, you’ll be increasing your weekly long runs by about a mile a week and increasing your inner weekly running miles. You should end up peaking somewhere between 22 and 30 miles the week before your half marathon race.

Related: Can you run a half marathon if you can run a 10K?

Find a half marathon training plan and stick to it

I believe that the best advice you can give any runner transitioning from a 5K or 10K to a half marathon is to find a training plan and stick to it. Most people that don’t ever make it to the starting line of their half marathon is usually because of injury or they didn’t follow a half marathon training plan.

Recently I ran my 15th half marathon race with only 4 weeks to train for the race. I created my own plan and used the 4 weeks time-based half marathon training plan version. I didn’t run my best half marathon and definitely wasn’t my worst. But I finished!

15th Half Marathon Race Finish
15th Half Marathon

Here are several of my training plans you can use if you’re transitioning from a 10K to the half marathon with limited time to train:

8-week beginner half marathon training plan

8-week intermediate half marathon training plan (easily run a 5K)

4-week advanced half marathon training plan (already run 6+ mile long runs)

Increase Your Long Run Distances

During your half marathon training you slowly, week-by-week, increase your long run distance so that your muscles can rebuild and expand so that you can run further the following week. Long runs need to be run at an RPE between 4 and 6 (rate of perceived exertion) which is an easy pace that you can carry on a conversation with someone else.

Are you struggling with long runs? Check out this detailed post about ways to:

Easy way to motivate yourself on your long runs.

Include Strength Work

More now than ever you need to start including strength training into your weekly routine at least once per week. This could be a gym workout that focuses on runner-specific exercise and includes full-body workouts. You can also get a great workout at home in 30 minutes with a kettlebell while including body-weight strength training right in your garage. Strength training will help your neuromuscular skeleton to make you stronger and be able to sustain impacts from running.

Do you need a strength training regime for runners? Check out this detailed post about essential strength training for runners.


Cross-training can consist of any type of exercise other than running. This can include and not be limited to, hiking, walking, biking, skiing, snowboarding, log rolling, yoga, etc.

Related: What are the best types of cross-training exercises for runners?

How to find your half marathon pace based on your 10K finish time

Pace predictors are great for new runners to find their estimated half marathon race pace. Basically, this assumes that if you run your previous races at a race pace of RPE 7-8+,  that you should be able to race at the predicted half marathon pace. There is a big however, You haven’t had any injuries, you haven’t gained an insurmountable amount of weight, your health is in good standing, and your race that you predicted your half marathon pace is less than 90 days ago.

So for a half marathon race prediction, the best indicator would be a 15K (9.3 miles) race. Since there aren’t many 15K races out there, in fact, I’ve only raced one in all of the 70+ races I’ve been in and it was a trail race. You need to rely on a more common race such as the 5K or 10K.

Predicting your half marathon pace based on a 10K race

This is probably the best indicator for predicting your half marathon pace and finish time. Running the distance of a 10K, however, isn’t required prior to running the distance of a half marathon. If you’ve run a 10K before it will only aid you in preparing for your first half marathon. Based on your current 10K race time calculate your finish time by 2.227 to determine your predicted half marathon finish time. After determining your finish time, divide the finish time by 13.1 miles to determine your half marathon predicted pace.

10K Example 1:

10K finish time: 60 minutes (1 hour)

Predicted half marathon finish time:  2.227 * 60 minutes = 2 hours 14 minutes

Miles: Predicted half marathon pace: 2 hours 14 minutes = 120 minutes + 14 minutes = 134 minutes / 13.1 miles = 10:13 minutes/mile

Kilometers: Predicted half marathon pace: 2 hours 14 minutes = 120 minutes + 14 minutes = 134 minutes / 21.1 kilometers = 6:21 minutes/kilometer

10K Example 2:

10K finish time: 75 minutes (1 hour 15 minutes)

Predicted half marathon finish time:  2.227 * 75 minutes = 2 hours 47 minutes 

Miles: Predicted half marathon pace: 2 hours 47 minutes = 120 minutes +  47 minutes = 167 minutes / 13.1 miles = 12:46 minutes/mile

Kilometers: Predicted half marathon pace: 2 hours 14 minutes = 120 minutes + 14 minutes = 167 minutes / 21.1 kilometers = 7:55 minutes/kilometer

Predicting your half marathon pace based on a 5K race

If you don’t have a current 10K finish time you can use your 5K average pace to determine your half marathon pace. Most runners, before attempting to conquer a half marathon, have more than likely run at least one 5K race. If you don’t have a 10K or 5K race pace, switch over to this detailed post about how long it should take to run a half marathon?

Half Marathon Pace Predictor based on 5K finish time

5K FT = 5K Finish Time
HM FT = Half Marathon Finish Time
Find your 5K finish time to predict your half marathon finish time

Don’t use a 5K/10K TRAIL race pace as your indicator

Why? You will always, ALWAYS, run slower on a trail versus a flat road course, unless your road course is extremely hilly. Even if your road race was extremely hilly, I would bet that 99% of runners still race slower on the trail. This is mainly due to your body naturally running in a wider stance because of your mental/physical subconscious throwing of precautious warning signs like – I don’t want to fall off this cliff.

If you’ve never run a trail race before I highly suggest giving it a go. Here is a great article I wrote for beginner trail runners:

Trail Running For Beginners – 8 Things to Know Before you go!

10K to Half Marathon Training Plan
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Work on fortifying your mental running thoughts

Your mental inner running critic will rear its ugly head, especially after 90 minutes of running. Your energy is zapped and without fuel, carbs, to rejolt your brain, you will start to lose the mental battle and lose overall focus and determination. Discovering how to quell your inner critic and excite your inner coach comes with years and years of running and fighting your inner critic. Here are some quick tips:

Quell your inner critic and excite your inner coach!

Strategy is everything

If you running your first half marathon, you need to run on a flat course. If you have no choice and your race is extremely hilly you might want to switch to walking up the hills and running down the hills just to survive.

So my only caveat to this is being careful what you sign up for because when life throws you off track, you have to adjust for the road ahead of you –  especially in the middle of a half marathon race. For more information on backup plans check out:

Have a backup plan for your half marathon/marathon (just in case)

Study your course route prior to your race

Also, when you look at your running route for your half marathon race (which you do before the race), take note of the water/aid stations. This will allow you to determine when you need to fuel. Also, this will give you an idea of whether or not you need to carry water with you for your half marathon race.

Also, knowing when to speed up or slow down during is race can help you finish with a better chip time. If the course flattens out for a substantial distance (1 or 2 miles), you may way to speed up your pace during these flats. On the other hand, if your race has several gradual inclines you might want to slow down your pace and save it for the latter part of the racecourse.

Take a glance at the weather as well prior to your race. A sustained headwind will definitely slow you down and you might want to double-check that you remembered to bring your wind sheering glasses so that your eyes don’t end up watering the entire race.

Speedwork optional

This is where some running coaches split hairs with each other. I look at each runner and determine if they are competitive racers or recreational weekend warrior racers.

Competitive racer

If they are competitive and plan on being competitive then I would go ahead and assign speedwork at least once a week to their training plan. You can add speed work such as lactate threshold runs, hill repeats, fartleks, 6 x 1200 meters x 3 min rest interval repeats, etc… So in order to run faster and longer, you need to increase your lactate threshold. This is the level where

Recreational racer

If this will be your first half marathon race I wouldn’t include speed work during your training, Unless you’ve previously included speedwork during your lower-end races. Speedwork takes a longer time to recover from than steady-state pace work, easy runs, and long runs. After you complete your first half marathon race, you can then consider using speedwork during training. For more information on half marathon training and whether or not to use speedwork, check this detailed post I wrote:

Should I include speedwork for my first half marathon race?

Treadmill speed workouts

Another great place to perform your speed workouts is the treadmill. No matter what the weather is doing outside, you can always go to the local gym to get in a good treadmill speed workout. If you’re fortunate enough, you might already have a treadmill at home so you don’t have to leave the house. For a list of 9 speedwork out drills you go do on a treadmill check out:

9 treadmill workouts for runners when you can’t run outside!

Can I train for a half marathon on a treadmill?

Should you fuel for a half marathon?

During the 10K you don’t, or shouldn’t require on-course fuel for your run. The half marathon is where you’ll probably want to consider fueling unless you can run a half marathon in less than 90 minutes (most of us can’t). Even if you can run a half marathon in less than 90 minutes a couple of energy gels will more than likely make you perform better during your race.

For a detailed article that dives deep into fueling and science-based facts of glycogen stores and fueling check out:

Should I fuel for a half marathon?

Huma Energy Gels
Huma Energy Gels – My Favorite!

Half Marathon Recovery is longer than 10K Recovery

A 10K race is much easier to recover from when compared to the half marathon. Some runners will experience some discomfort for 1 or 2 days following a 10K race. While on the other hand, some runners can experience 5-7 days of discomfort after running a half marathon race. Remember that a half marathon is more than double the distance of a 10K race, therefore it makes sense that your body will take longer to recover and repair itself after a half marathon race. I have written a great guide on how to recover after your half marathon race. Check it out here:

What is a recovery run?

Half marathon recovery – 10 tips to help you recover faster

Log Your Runs (If you haven’t already started)

I’m not going to lie. Transitioning from a 10K to a half marathon is doable with the right training, however, it will take motivation and perseverance to get there. The average runner (mainly the recreational runner), will probably never run a half marathon. Having said that doesn’t mean it’s impossible. I’m 47 and running my 15th half marathon this Sunday.

One way to keep focused is to have a training plan, and log your progress along the way. Most smartwatches and phones can easily log the information for you, however, how many of us actually look back over the data. My running changed forever when I actually bought a physical training log and started using it every day.

The 365-Day Running Journal (Amazon Link) is a super popular training journal/log that I use. It’s just the right size at 5 inches x 7 inches (12.5 cm by 17.5 cm).

Are You Considering A Full Marathon Race?

If you’ve recently completed your first half marathon and you’re considering a full marathon race, it’s going to take you roughly another 8 weeks to be able to run the full marathon, at a minimum. I ran my first half marathon race and then immediately started training for my first marathon race which was 12 weeks later.

One way to line up your first half marathon race while training for a  marathon race is to treat your first half marathon race as simply one of your upper long runs of 13.1 miles. Run at an easy pace and simply complete the half marathon race. You will have completed two tasks with one run: 1) finished a half marathon race and 2) completed a long run in your marathon training schedule.

For a full post on transitioning from a half marathon to a marathon race check out: From Half To Full: 10 Ways To Transition To A Full Marathon.

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Coach Scott's Credentials:
  • Published Author
  • RRCA Certified Running Coach (Level 2)
  • RRCA Certified Youth Running Coach
  • NASM CPT (Certified Personal Trainer).
  • NASM CNC (Certified Nutrition Coach)
  • NASM WLS (Weight Loss Specialist)
  • ACE SFC (Stretching and Flexibility Coach)
  • ACE GFI (Group Fitness Instructor)
He has published over 20 books including, Beginner's Guide to Half Marathons: A Simple Step-By-Step Solution to Get You to the Finish Line in 12 Weeks! (Beginner To Finisher Book 3), which has become an Amazon International #1 bestseller. Scott specializes in helping new runners become injury-free race finishers. He recently completed his 22nd half marathon race. 

 To sign up for a FREE half marathon training schedule, log sheet, and pace predictor CLICK HERE.

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