The Scientific Benefits of Long Runs

Every runner should be doing long runs. Even if you’re just training for a 5k, you still need to do a long run. I’ll tell you why.

About a year after my son was born, I decided to get more competitive with my running. I sought the help of coach Bobby Holcombe, founder of Knoxville Endurance, and told him my goal was to run a sub-18 minute 5k.

I had chosen this goal because I thought the training would be less time-consuming than for a marathon. Low mileage. No weekend long runs. I was wrong.

Related: A proven guide for running injury prevention

15 tips to make long runs successful
Pin this for later! 15 tips to make long runs successful

Turns out every runner should be doing a weekly long runWhy? Because running long makes you a better, stronger, and faster runner. How amazing is that? Just by logging in some extra miles, you’re going to see results!

How do long runs make you faster?

Long runs (aka long, slow distance or LSD):

  1. Build the number of mitochondria in your cells. These are the “energy factories” that power movement and cell respiration.
  2. Increase max VO2 and blood volume, maximum stroke volume (the amount of blood ejected from the heart with each beat), and build new capillaries and red blood cells.
  3. Build mental toughness. When you toe the start line, you know you can go the distance because you already have—and in some cases—and then some.
  4. Make your running more efficient. Muscles learn through practice, so your stride will improve through consistent long runs.
  5. Teach your body how to fuel itself. Your body will learn to tap into fat before glycogen, delaying glycogen depletion during a long race. This helps delay hitting that proverbial wall.
  6. Make your muscles and tendons stronger. Running for prolonged periods increases the strength of the leg muscles and connective tissues.
  7. Open-up the chest cavity because you’re breathing longer at a faster rate. This strengthens your respiratory system.
  8. Make you faster! By improving your endurance, you’ll be able to hold a certain pace for a longer period of time. And, then as your slow-twitch muscles get tired, your fast-twitch muscle fibers pitch in. 

How often should you do a long run?

Typically, the long run is done once per week that’s to allow for your body to adapt. As The Mother Runners co-coach Laura Norris explains, “A long run produces a significant amount of damage – which requires recovery in order to adapt. Too frequent of long runs can also compromise the quality of training in between – and those runs matter too!” (Get more tips on increasing stamina here.)

How long should my long run be?

Most experts, included famed coach Jack Daniels, agree that 20 to 30 percent of your weekly mileage should be devoted to a long run. If you’re running 40 miles a week, then your long run should be about 8-10 miles. A runner averaging 80 miles per week would go 16-20 miles. An elite marathoner running 100 miles a week would be running 20 miles in their long runs. These guidelines scale the run to your current ability level and training load. (Check out this article on how many miles you should run a week by The Mother Runners head coach Laura Norris).

How long is a long run?

Long runs are considered long if they last more than an hour.

Long runs are typically considered to last between one and three hours.

Related: Self-care tips for busy moms

How fast should I run my long run?

Long runs should be performed at a pace that is comfortable and conversational. This pace is roughly one minute slower than your marathon race pace, or around 90 seconds per mile slower than your current 10K pace and two minutes slower than your 5k pace.

Running at these easy paces teaches the body to tap into your fuel sources efficiently so that it learns to use both carbs and fats. 

“When you run below your aerobic threshold (slower than marathon to 50K pace for most runners), you utilize both fat and carbohydrates for two separate pathways of aerobic metabolism,” explains Laura, also founder of Laura Norris Running. “If you go too fast, your body converts to just aerobic metabolism with carbohydrates (assuming you stay below your anaerobic threshold); while you still use fat, you neglect fully adapting the fat utilization. Slowing down trains your body to use both energy systems – and helps bonk-proof your marathon.”  

What should I eat on long runs?

Eat a carb-dense meal of about 300 calories about an hour before. Take a gel about every 30-45 minutes with water. Eat a carb and protein-dense snack of about 300 calories or more within 30 minutes of completing your run. Then eat another meal full of carbs, proteins, and healthy fats about 2 hours after your run. This is key to recovery.

Related: 3 proven ways to refuel after a long run (& 2 yummy recipes)

How can I make a long run easier?

15 Tips for Successful Long Runs

  1. Slow your pace. Remember, you got to go easy to go fast! Don’t make the run harder than it needs to be. Some long runs may have you do a tempo in the middle or a pick-up at the end. If that is the case, then yes, do that but be sure to run EASY the rest of the miles. 
  2. Mentally break the run into sections. If you have a 12 miler, after you do 6, then another 6 is like a weekday run. No big deal!
  3. Entertain yourself. Run with friends, music, podcasts, or audiobooks. (Get more tips on avoiding boredom here).
  4. Do just one long run per week. This avoids mentally and physically over-taxing the body.
  5. Take a break. Scale down your long run by 30 percent every 4 weeks (also known as a down or cutback week) to absorb your training.
  6. Take walk breaks as needed. The goal is “time on feet” so walk breaks save your muscles and tendons from over-use but don’t impede the physiological adaptations.
  7. Focus on eating within 30 minutes of finishing your run and then another meal about 2 hours after that.
    Focus on eating within 30 minutes of finishing your run and then another meal about 2 hours after that.

    Focus on fueling! Eat a carb-dense meal about an hour before. Take a gel about every 30-45 minutes with water. Eat a carb and protein-dense snack within 30 minutes of completing your run. Then eat another meal full of carbs, proteins, and healthy fats about 90 minutes after that. This is key to recovery.

  8. Hydrate! Focus on hydrating starting the day before your long run. Drink water or electrolytes before and after your runs. Aim to get your weight back to pre-run weight when hydrating. Drink to thirst during your runs. 
  9. Lube up. Avoid chaffing by using vaseline or an anti-chaffing stick on areas such as under your arms, your inner thighs, your waist- and sport bra-bands. This is crucial in warmer months.
  10. Increase gradually. Only increase a long run by 1-2 miles per week. 
  11. Take it easy. With the exception of ultramarathon training, the next day should be focused on recovery. Light foam rolling, stretching, and walking should be the only thing related to exercise you should be doing!
  12. Plan ahead. Tell the family what time you plan on going and about how long you will be. This helps avoid meltdowns from kids when they wake-up and mommy isn’t home.
  13. Be prepared for pick-up. Also, be prepared for the house to be a wreck when you get home because your partner or sitter was focused on entertaining the kids. It’s also not uncommon for me to come home to them all sitting around eating donuts! Your run time can be a wonderful bonding time for them!
  14. Recover! Let your family know that it is important you get some time to eat, foam roll, and take a shower when you walk in the door. Try to resist going right back into mom-mode when you walk in the door. Take a couple of minutes to rehab. (And remember, if you are truly running easy, you should not be completely gassed from your long run.) 
  15. Be patient and trust the process! It typically takes about 10-14 weeks for the physiological adaptations to be made. Your fitness will come! (Get more long-distance training tips here.

Go long, mother runners! 

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PS-I’d love to help you reach your running goals whether it be to run your first 5k or run competitively! Email me at with questions or check out my Coaching Services page!

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