How Long Does It Take To Get Out Of Running Shape?


Exercising and sticking to your running schedule is important. But sometimes the best thing you can do for yourself is to take a break. Whether it’s planned or unplanned (i.e. injury) detraining is a part of the running life.

Regular rest days are built into your running schedule, and make you stronger in the long run. And if you’ve just finished running a marathon, or if it’s the end of running season, there’s no harm in taking some extra time off.

It can be good for both the body and the mind. It can also help to reduce the risk of injury or even burnout. Some runner, though, worry that they will lose all their fitness. This worry is, for the most part, unfounded. All the hard work that you’ve put in over the months won’t disappear overnight, or even over the course of a few weeks.

That being said, there is a point at which your fitness will start to suffer. In this article, we’ll cover how long it takes to lose your running fitness, whether it’s from a planned rest break or something out of your control.

Reasons You Might Stop Running

If you’ve been pushing yourself too hard, you may find that you need a break due to overtraining. Or you may have developed an injury that needs to heal. Both overtraining and injury could put a hold on your running for a few weeks.

Illness can also put a pause on your running. If you have a mild cold where the symptoms are above your neck you can still run, but it’s advisable to keep your runs short. If the symptoms have moved below the neck and into your chest, it’s best to give your body time to recover.

Work schedules or projects may have runners needing to adjust or take some time away from running, especially if the projects have tight deadlines. Depending on the type of project or business need, you may find yourself having to travel for meetings, which could limit the amount of time you have available for running.

Things like vacations or family responsibilities may also put your running on hold for a bit.

Even if you’re passionate about running and have a goal to achieve, you can become demotivated. There are a number of reasons why you may feel demotivated. Maybe you feel that you’ve hit a wall with your training. Or you may find it difficult to start running again after an injury.

After months of training and crossing the finishing line of a long race, you may find that your body will benefit from an extended recovery break.

When To Take A Running Break

Months of training and running takes a toll on your body. The same training breakdown that helped you to reach your fitness gains can also be the breakdown that becomes counterproductive.

Give your muscles, ligaments, tendons, and bones time to rest and recover. In doing so, you’re helping your body to become stronger. If you continue to push without adequate rest, you’re putting yourself at risk of injury from overtraining.

It’s also important that you give your body a break from the impact forces of running. Impact-related injuries take time to develop, like stress fractures.

But they do manifest rather quickly and can lead to longer recovery times. By taking the time to rest, you’re giving your body the opportunity to heal.

Running doesn’t just challenge the body. It can also be mentally demanding. And it can be difficult to maintain focus continuously when you run. This can lead to you not being able to perform or train at your best.

Taking a break allows you to focus on doing other things that interest you. It also carves out a bit of time to reevaluate your goals. Such reflection is necessary to setting new goals and focusing better when you return to running.

How long does it take for your fitness to decline?

There are a number of factors that determine how quickly your fitness levels decline when you stop running. Age, level of fitness, body composition, how long you’ve been exercising for, and what your performance level is before you take a break will all affect your fitness decline.

You also need to take the length of your break and how active you are into consideration. Fitness levels don’t decline as quickly in runners who have been training for years. Runners new to the sport often see their gains slip away more quickly.

The amount of lean muscle you have is especially important to maintaining fitness during a break. The more lean muscle you have, the better your body will respond to down time. While aerobic fitness may start to decline after two weeks, muscles take a bit longer to decline.

When does loss of fitness happen?

You may find that within the first week of your break, you start to feel as if you’re already out of shape. This is due to the nervous system and brain that both gain and lose adaptation the fastest.  Changes to the mitochondria and your metabolic level will take longer – many weeks – to occur.

While you may only experience a slight performance loss after 6 weeks, you can stretch your break up to 8 weeks and still be able to bounce back quickly when you return.

That being said, if your break is longer than 8 weeks, regaining fitness will likely take longer. If you’ve only been training for 3 to 4 months, you may find after 8 weeks that you’re right back at square one.

A good way to monitor your fitness level is to track your resting heart rate. If you see that your resting heart rate has increased noticeably, chances are that your fitness level has started to decline.

How much will VO2 max decline?

When we look at VO2 max, we are essentially looking at the volume—V—of oxygen—O2—that is consumed by a person when they exercise. This is measured in milliliters per kilogram of body weight per minute and is used to measure cardiovascular fitness.

Studies have shown that within the first 10 days of taking a break, there’s no change to VO2 max. But your stats will dip significantly after 2 to 4 weeks of inactivity. VO2 max can decrease by as much as 6% after 4 weeks, up to 19% after 2 months, and as much as 25% after 3 months.

This happens due to our cardiovascular systems not working harder to pump blood. A key aspect of fitness is increasing your heart’s stroke volume. As your heart gets out of shape, that volume decreases. 

An example of a runner who runs 20:00 for 5k

There are a number of factors that affect your VO2 max. Age, body composition, gender, altitude, temperature, and genetics all have their influence. It’s important to note that as we get older, our VO2 max declines by approximately 2% every year after the age of 30.

Let’s say a runner has trained consistently for 6 months for a 5k. They run it in 20:00, and their VO2 Max is measured at 50.

If they took a total break for 2 weeks, they’d lose 6% of their VO2 max, dropping it to about 47. According to estimates, this predicts they’d run their next 5k in 21:05.

After 2 months, they’d lose 19% of their VO2 max, making their VO2 max about 40. Their time might slow to 24:00. The good news is that you can increase your fitness and VO2 levels quickly once you start running again.

How can you keep fitness when not running?

If you’re not nursing a serious injury and you’re just taking some time off from running, you’ll be able to maintain your fitness level.

Strength training is one of the best ways. Lifting not only maintains your fitness levels, but helps to develop muscle and increase your strength. Strength training will also help to reduce the risk of injury and keep joints healthy and strong.

You can maintain your level of fitness this way indefinitely. You might not stay in running shape specifically, but you will maintain fitness generally. Balance the loss in training volume with an increase in intensity. All you need to do is a 30-minute high-intensity workout 2 to 3 times a week. This will help to maintain a higher level of fitness while you take a break from running.

It’s important to remember that when you start running again, you’re not going to be running as fast or as far as you did before you stopped training.

Especially if you’ve taken a 3-month break. Start gradually. You’ll find that within 2 to 4 weeks, your running performance will be almost back to what it was before your break.

Take advice from a coach

Before you take your break, reach out to a running coach. They’ll be able to help you put a plan together that would accommodate your recovery and lifestyle. This plan will also make it easier and quicker for you to get back to running your personal best.

If there are any other areas of your running that you feel need improvement, a running coach will also be able to help you with this.

Photo of author


Ben is an avid road and trail runner, and has completed multiple marathons and ultras. A former running store owner, he now shares his knowledge and experience writing these articles.