Determining your weekly mileage during race training is a delicate balance: You want to run enough miles to physically prepare your body without running so much that you end up overtaxing yourself and toeing the starting line spent—or worse, injured.
It’s also individualized as it depends on your speed, strength, experience, base, and goals. Unfortunately, there’s no one-size-fits-all prescription for how many miles a week to run.
That said, start where you are right now, says Melanie Kann, an RRCA-certified running coach for New York Road Runners.
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“If you’re running your first 5K, you might start with a minimum five-mile-per-week program. If you’re running your first marathon, you might start with a minimum of 15 miles per week,” Kann says.
Rather than looking for a specific mileage plan, think of it more like building up to a certain amount of time on your feet. “This allows the runner to progress safely,” says fitness instructor Rich Velazquez.
Still, there are a few rules of thumb and general guidelines that can help you come up with how many miles a week to run. And, determining how many miles to run for a race first means knowing how many miles are in the distance you’re choosing.
- How many miles in a 5K: 3.1
- How many miles in a 10K: 6.2
- How many miles in a half marathon: 13.1
- How many miles in a marathon: 26.2
Here’s how to figure out the best plan for you.
Rule 1: The longer the race, the higher the mileage.
If you’re training for a marathon, you’re obviously going to need to log more weekly miles than if you’re training for a 5K. No matter the race distance, though, there are three main components to a cohesive running program, says Velazquez: a long run day, a speed day, and a recovery day.
“Your long run should be conducted at a slow pace and eventually last as long as your projected race time (remember, it’s about time on feet versus miles); your speed day is shorter in duration but faster than your predicted race pace; and your recovery day should be an easy/slow pace and lower mileage than your planned race,” he says.
So you’ll have some longer runs and some shorter runs no matter what you’re training for; the ultimate mileage, of course, depends on your race distance.
Rule 2: Mileage requirements increase as performance goals increase.
If your goal is simply to finish a race, you can run fewer miles than if your goal is to finish with a fast time. “But as your goals shift toward performance, weekly mileage will most likely increase to support the demands of these goals: aerobic capability, energy utilization and sustainability over elongated periods of time, and efficiency of movement,” says Velazquez.
That’s because logging that time on your feet is what’s going to give you a stronger engine, adds Kann. “Obviously, your musculoskeletal system is going to get stronger as you spend more time on your feet,” she says.
“But when you’re out there running, you’re fueled by oxygen—that’s what gets your muscles to fire and gets the blood moving around. So the more time you spend on your feet, the more it’s going to increase the capacity of your aerobic engine, which is going to fuel you to go stronger for longer.”
Rule 3: Not all miles are created equally.
No runner should go out and run the same pace every day; any good training plan should include speed, interval, tempo, and distance training, all of which offer different benefits.
“Speed training is where the body will shape and improve its running economy (energy demand for a given speed) thus improving overall efficiency in energy consumption and oxygen utilization,” says Velazquez. “Interval training aligns specific speeds with specific intervals and set rest periods, tempo running is about maintaining consistent speeds over longer periods of time, and distance training is about getting the body used to impact and elongated performance.”
The point of all those different training modalities? Ideally, you become a better, more well-rounded runner.
“If you only run at race pace, that’s the only pace you know,” says Kann. “You want to get your system ready to be comfortable moving at paces faster than race pace, so that when you get to race day, that pace doesn't feel so hard.”
While the bulk of your miles should be easy, aerobic-based miles, those faster miles get you to that point where you're clearing away the waste product in your muscles at the same rate that you're accumulating it, she explains, which will make your body more efficient come race day.
Rule 4: Allow for adaptation when increasing mileage.
To avoid injury when upping your mileage, you need to take it slow and allow your body time to adapt to the increased workload. Many runners follow the 10 percent rule—i.e. never increasing your weekly mileage by more than 10 percent over the previous week.
“Most programs will build mileage week over week for about three weeks before introducing in a low mileage week (recovery),” Velasquez says. “From there, the buildup will start again as the body should have adapted from the increased volume with the rest and be ready and able to tackle more.”
Think about your runs in terms of quality over quantity, Kann says. “If you’re adding additional speed workouts to your week, you don’t want to run a super long run that weekend,” she says. “You’re just asking a lot of your body all in a short period of time.” Your body, on a microscopic level, is breaking down muscle tissue when you run, and it needs to time to rebuild (that’s how you get stronger).
It’s important to look at the whole picture when it comes to weekly mileage, and think about the kind of miles you’re running and how that will impact your body.
Rule 5: Listen to your body.
When you’re following a training plan, it’s natural to want to hit the exact mileage that’s indicated—that’s how it works, right? “We always tell people to start with a plan, but that plan is not the letter of the law,” says Kann. “It's not like you're going to get a failing grade if you don’t stick to that plan 100 percent.”
Running mileage just for the sake of running mileage can actually backfire, because overtraining can lead to a general disintegration of performance or even injury. “Broken sleep, elevated resting heart rate, lack of motivation and restlessness are all signs of overtraining,” says Velasquez.
With running comes a certain level of discomfort; part of the challenge is pushing yourself past those I-don’t-know-if-I-can-do-this boundaries. But Kann doesn’t advocate running through pain.
“Discomfort naturally comes with training as your body adapts, but if you feel the pain on one side of your body and not on the other or if you’re dealing with some kind of persistent pain, that's a sign that there's some kind of imbalance at play,” she says. When in doubt, err on the side of caution and pull back your pace or take a rest day. No runner ever healed any kind of pain or injury by running more.
Rule 6: A healthy runner beats an injured runner every time.
At the end of the day, the most important goal of any runner—whether you’re running a marathon, half marathon, 10K, or 5K—is to make it to the starting line without injury.
“The last thing you want is to overload yourself, break yourself down, and then push yourself past your limits,” says Kann. “That’s when you're gonna pull yourself out of the game for three weeks to recover. Then you’re really in trouble.”
“If you’re not feeling up to run, rest and reschedule,” says Velazquez. “And should that feeling persist, people training for longer races (i.e. a marathon) should give priority to the long run over the speed training.”
Remember: No one’s grading you on how well you stick to a mass-produced plan anyone on the internet can download. The real test is race day, and just how well you can get through it.
Rule 7: Adjust your base accordingly when coming back from injury.
You had your weekly mileage mastered when you were healthy, but if you’re sidelined with an injury, it requires a tweak. Before you get back to running, make sure you can walk for at least 45 minutes without pain, says exercise physiologist Susan Paul. Walking will help recondition your muscles, tendons, and ligaments to prepare for the more vigorous demands of running to come.
Then, you need to consider how long you’ve been off, adds Adam St. Pierre, a coach for CTS in Colorado Springs. If you’ve been sidelined for a week or less, you can pick up where you left off. (You may even feel better when you do!) But for a break of up to 10 days, start running at 70 percent of your mileage. For 15 to 30 days off, dial back to 60 percent. For a hiatus of 30 days to three months, start at half of your previous mileage. If you’ve been off more than three months, you should start your weekly mileage from scratch.
Target Totals:
The number of weekly miles to shoot for differs based on goals, baseline, and experience, but here’s an estimation to help guide you.
- 5K: 10 to 25
- 10K: 25 to 30
- Half Marathon: 30 to 40
- Marathon: 30 to 60
