Three Reasons Why You Should Not Run A Marathon

Marathon participation around the world continues to boom. In 2018, 1,298,725 people completed the full 26.2-mile race, a nearly 50% increase in worldwide participation from 2008. Running the vaunted distance is the de facto goal for many beginner runners.

Experienced runners are also increasingly drawn to the popular distance as an opportunity to compare personal bests with their running buddies. When it seems like everyone is training for a marathon, the pressure to run one yourself can seem daunting.

Is it possible, however, that training for and racing a marathon might not be in your best interest?

Let’s take a look at reasons why temporarily reconsidering your marathon racing plans might pay off for you in the long run.

You Don’t Have Enough Training Background

The first and perhaps most obvious reason you might not want to run a marathon is a lack of training or an experienced running background. The marathon is an arduous event and requires a dedicated training block of at least two months for serious runners and four months or more for newer runners. Remember, the more time you give yourself to train for your goal race, the better your chances of success.

More importantly, training for a marathon when you don’t have the requisite running background is a surefire way to get injured or find yourself disenchanted with running if you’re new to the sport. In my experience as a coach, I’ve found that beginners need to be able to average at least 40 miles per week for 5-6 weeks to increase the chance that they will have a good race experience. This means that you need to be able to comfortably run 30-35 miles per week before you begin training for a marathon.

If you’re not at this number, it doesn’t mean you can never train for a marathon. Rather, you should focus on slowly building your training tolerance and mileage background. Otherwise, you’ll likely struggle to increase the length of your long runs, as well your weekly mileage, enough to be adequately prepared on race day.

When runners neglect this advice, they often find themselves in a vicious injury cycle that is tough to break free from. First, the sharp initial increase in training results in a small injury that sets them back a week. To make up for missed time, they push the envelope to get back on track and develop another small injury. The cycle repeats itself throughout the entire training segment until race week when a runner realizes has not put together a solid, uninterrupted month of training since they started.

The last thing anyone wants on marathon race day is to have a bad experience and to suffer through the course. Even if your goal is only to finish, make sure you have the necessary running background to start marathon training on the right foot to stay injury-free and to have a good race.

You Have Too Many Other Racing Goals

To run to your potential in the marathon, the required training is drastically different than any other commonly run racing distance. Training for the marathon requires a very specific 8-12 week training block, which necessitates a singular focus that is often detrimental to your short-term performance at shorter races like the 10K and half marathon.

The mistake of trying to accomplish too many secondary goals while training for a marathon is one of the biggest mistakes I encounter when working with veteran runners. Here’s a typical conversation I’ve had during a first consultation:

Joe Runner: “I want more than anything to qualify for Boston at my next marathon. I am only 8 minutes away from the qualifying time.”

Me: “Great. We have four months to train and looking at the weaknesses in your prior training plan, I can definitely see 8 minutes improvement.”

Joe: “Wow, I am excited! I also want to do two half marathons and shoot for a PR, two local 5Ks to beat my local rival, a 48-hour relay race, and pace my friend through his first marathon.”

Me: “Whoa, wait, what? To drop 8 minutes from your marathon PR, we need to do everything right in this training block. Where are the long runs supposed to go? When can we do any marathon-specific workouts if you’re always racing?”

While my example sounds extreme, think of how your last marathon training segments have looked — I bet you’ll see a similarity. Unfortunately, and more often than not, a runner who attempts to accomplish too many secondary goals when training for the marathon realizes poor performances — both at the shorter distance and the marathon itself, thanks to unspecific training.

Unlike other events like the 10K, or even the half marathon, training for the marathon necessitates a specific focus on physiological adaptations that aren’t of great importance to shorter races. In the marathon, the primary focus of training is developing your aerobic threshold (the fastest pace you can run while staying aerobic), increasing muscular endurance (how long you can run without your legs falling apart), and fuel efficiency (how efficient you can be at burning fat instead of carbohydrates while running at goal marathon pace). At no other race-distance are these three training adaptations so important. Therefore, to train for the marathon correctly, you need to temporarily neglect the specific training demands of shorter events.

Furthermore, to accomplish many of the aforementioned training adaptations, you need to practice running on tired legs or with low energy levels. This philosophy is often called “accumulated fatigue.” Basically, this means that the fatigue from one workout accumulates and transfers to the next so that you’re always starting a workout or a long run a little tired from your previous training.

This type of training helps your body adapt to performing better during the last half of the marathon race. Consequently, it’s very difficult to race well at other distances when training appropriately for the marathon because your legs should, and will, often be in a state of accumulated fatigue. More often than not, strong performances at 5K or 10K races during marathon training can indicate that your marathon training isn’t specific enough.

If you’re training for the marathon, you have to realize that performance at shorter distances will suffer in the short term. If you still want to run well at other distances, perhaps a marathon isn’t the best goal for this training segment.

You Need a Change

While there is no doubt training for the marathon helps you improve your aerobic development, increases your mileage tolerance, and can be great for building endurance, training for multiple marathons in a row isn’t the best option for your long-term development. In fact, racing marathon after marathon often leads to stagnant results and a lack of progression.

As covered earlier, training correctly for the marathon requires an intense focus on the specific demands of the marathon race. Very rarely in marathon training should you be doing VO2 max, high anaerobic threshold runs, or pure speed workouts (notice I said rarely, not never). These are training adaptations that are important for success at shorter distances but don’t translate well to good marathon racing.

Unfortunately, if you neglect certain energy systems or physiological elements for a long period of time, you start to lose overall fitness. To continually improve, the body needs a change of stimulus — a new type of demand for the muscles and body.

Desiree Davilla of the Hansons-Brooks Distance Project is a perfect example of how marathoners need to take a break from a marathon training cycle to consistently improve. After a great performance at the 2009 world championships, Desi took a break from the roads and focused on hitting the track to improve her speed. The result was a jaw-dropping performance at the 2011 Boston Marathon.

If you’ve done more than three marathons in a row without dedicating a specific training block to 5K or 10K training, running another marathon might not be the best choice if you want to record a new PR.

With the extreme popularity and accessibility of marathons these days, it can be hard to forgo the temptation to race one every season. However, if you’re a new runner or a veteran looking to break through to the next level, perhaps you should look closely at your training and goals to determine if running another marathon is the right choice for you.