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When I first started running, the only distance I ever did was a 5K. Before long, I was able to run further distances. After a while, I took part in my first half marathon and achieved a time of 1 hour and 50 minutes. This got me thinking, is it possible to run a half marathon straight away if you can run a 5K?
As a general rule, it is possible to run a half marathon if you can run a 5K, providing that you have done a couple of weeks of training in between. But it can depend on your current level of fitness. However, if you are wanting to avoid injury or are aiming for a personal best, it is much more efficient to follow an official half-marathon training program rather than trying to jump straight from 5K to half marathon.
To give you as clear an answer as possible as to whether or not you would be able to run a half marathon if you can run a 5K, I got some opinions from other runners and also looked into some of the pros and cons to going straight from a 5K to a half marathon.
What Runners Think
First, I headed onto this online running forum to ask real runners what their thoughts were when going straight from a 5K to a half-marathon. 366 runners voted. The results are in.
| Choice | Votes (%) |
| Yes | 86 (23.5%) |
| No | 77 (21.0%) |
| It Depends On Your Current Level Of Fitness | 203 (55.5%) |
Looking at the data above, it seems that more than half of the runners who voted believed it will come down to your current level of fitness if you’re considering going straight from running a 5K to a half marathon. Some of the runners who voted had this to say:
“I think there’s a big difference between “can” (I.e. “being able to”) and having “no issue”. I chose “it depends on your current fitness” because I know a ton of people who can bang out a 5k with no training if you asked them, but that would fall apart going much longer than that. When I was training for my first half, a lot of people told me if I could do an 8-mile long run I’d be fine in a half, and that feels more true to me. But there’s too much variation in what running a 5k looks like here to say yes or no, and there will always be exceptions and outliers.”
AAmadeus95
“I ran a marathon in October and I would struggle to run a half right now. I wholeheartedly think anyone can run a half marathon if you can put in the time to run at least 3 days a week!”
hannahstarnes
“I’d say more if you can run 10k you could possibly run a half.
The thing is, if you can run 10k and be ok with it (like, you feel slightly sore, but you could go on; and the following day(s) you’re not sore and you’re walking around like it’s nothing) and you’re in general good shape, then you might be able to pull it off.
But it’s really hard to say without knowing your past sport experience and your current situation.”
Dr3vvv
Looking at what other runners had to say, it seems like it really does depend on your current level of fitness whether or not you would be able to go straight from running a 5K to a half marathon.
By the way, is this article interests to you may be also interested in checking out the post I’ve written on how much you can run a week before taking a half marathon.
How To Know If You Can Go from Running 5K To Half Marathon
If it’s your current level of fitness that determines whether or not you’d be able to go straight from 5K to a half marathon then there are some specific milestones that should help you to determine whether or not you could take on this goal.
Simply put, if you can do any of the following then running a half marathon should be possible.
- Run a 5K every day of the week – Being able to run a 5K every day of the week would imply that you have a level of fitness that allows you to recover quickly and efficiently. If you’re able to put out this many workout routines easily it could be a sign that you’re not pushing yourself hard enough and that it may be time to try to take on a further distance.
Furthermore, the combined distance that you would be running on a weekly basis would be 21 miles, which is 8 miles more than that of a half marathon. With this being said, I would always advise that you take at least one day off the rest and recovery so that you can avoid injuring yourself.
- Do other vigorous workouts alongside your 5K – Another sign that you could afford to push yourself a little harder. If you can do strenuous workouts such as CrossFit, powerlifting, or HIIT workouts then it could be a sign that your body would be able to take on a half marathon. Not only that, but by doing lots of other kinds of exercises besides running, you would be able to build up different types of strength and conditioning which could assist you in running a half marathon.
- Run a 5K in under 25 minutes – For many runners, this can be a difficult goal to achieve. Personally, I’ve only ever been able to complete a 5K in under 25 minutes a handful of times. Completing 5K in under 25 minutes would imply that you have a good amount of speed and endurance which would support you in running a half marathon – providing your able to pace yourself. If you’re wondering whether or not you’d be able to reach this kind of time then you might find this article I wrote on average 5K times very useful.
- Run longer distances alongside your 5K – If you’re able to run 5K on a regular basis but also take on longer distances such as 10k or 8 miles then you would be running at a distance that is much closer to a half marathon and possibly more achievable.
An easy way to figure out if this is you would be by running 5 miles the day after a 5K and seeing how you feel. If your muscles are sore and you feel like you wouldn’t be able to run any further, then it might be time to take it back to a 5K. On the other hand, if you feel like you could keep going with ease then you may be able to take on a half marathon after all.
5K To Half Marathon Training Plan
It’s important to know that just because you can run 5K, it doesn’t necessarily mean that you should try to take on a half marathon immediately. There are many half marathon training programs that have been designed for runners who can competently complete 5K or 10K runs.
However, the majority of these training plans are still carried out over 12 weeks. Check out these training plans by Run-And-Become, for example, which are designed for intermediates who can easily complete a 5K or 10K.
If you’re someone who can run a 5K, a training plan for a half marathon will typically involve runs that are no longer than 5 miles regularly combined with weekly long runs that can be anywhere from 8 to 12 miles. It’s all about making sure that you are in a position where you will be able to run a half marathon without struggling.
By the way, if you’re looking for more of an in-depth guide to the training you need to do when trying to go from a 5K to a half marathon Then I would highly recommend this book, Faster Road Racing: 5K to Half Marathon that’s available to buy from Amazon. The chapters run through everything from training components to tapering for peak performance.
So, now we know exactly what to expect when it comes to going straight from a 5K to half marathon, we should look at some of the positives and negatives that you can expect to get out of it.
Positives You Will Get Going From 5K To Half Marathon
Mixes Training Up
If you’ve been competently running 5K for a while you may be in a position where you’ve become bored and are wanting to mix things up. By deciding to take up a half marathon you can take a fresh approach to your running and focus on new elements such as monitoring your speed, pace and endurance to make sure it matches up to the standard you would need for a half marathon.
Mixing up your training for a half marathon wouldn’t just involve doing other kinds of runs. It can also mean adding different workouts to your training plans such as weight lifting or CrossFit.
You’ll Find Out If Distance Running is for You
You might have been toying with the idea of running a half marathon for a while but not being sure if it’s the right distance for you. Whilst many people thrive by running shorter distances such as a 5K or 10K it can be hard to find the motivation, discipline, and perseverance needed to take on a half marathon. By going straight from a 5K to a half marathon in as short a time as possible, you can get an idea quickly and easily as to whether or not long-distance running is for you.
Greater Health Benefits
Whilst the 5K can be excellent for your health, there are also some fantastic benefits to running a half-marathon. For example, the amount of calories you will burn on a half-marathon is significantly higher than that of a 5K. Whilst the average person would burn around 300 calories during a 5K, the same runner could expect to burn approximately 1300 calories on a half marathon. If this sort of thing interests you then I would highly recommend checking out this article I wrote on some of the top benefits I noticed when I started running 5K.
Negatives You Will Get Going From 5K To Half Marathon
Acute injuries
Trying to go straight from the distance of a 5K to a half marathon could lead to some significant injuries. This is because your body is unlikely to have been properly conditioned without going through a proper training plan. Typical injuries would include Runner’s Knee and plantar fasciitis as well as blisters. You can learn more about how to run through injury and manage pain here. You can also learn more about running with blisters here.
Less Likely To Finish
According to the New York Post, as many as 1.3% of marathon runners never finish. Perhaps this number is slightly higher than what we would expect to see for somebody running a half marathon because the distance is more than double.
That Being sad, there’s no denying it a certain number of people will not complete the half marathon they set out to. This can be down to several reasons, many of which were out of our control. Examples include hitting the wall (read more about that here) and picking up injuries along the way. But perhaps the most common reason for not being able to complete a half marathon is poor preparation. For this reason, I would say that even if you can successfully complete a 5K, you should still take 12 weeks out of training before taking on a half marathon.
Can I Run a Half Marathon if I Can Do 10K
When wondering whether or not you’d be able to take on a half marathon if you can run a 10k the rules are still very similar to running a 5K.
If you can run a 10k in a sufficient amount of time on a frequent basis without picking up any serious injuries then it may be ok to take on a half marathon. That being the case I would still strongly recommend that any runner who can effectively run a 10k still undergoes an intermediate or advanced half marathon training plan.
