Anaerobic Running: What Is It and Should You Do It?

You’ve probably heard the phrase anaerobic running tossed around by training pals, running magazines, or fitness Facebook groups. But what exactly is anaerobic running? And should you actually be including this in your training plan? Let’s take a look…

Disclaimer: This post was written and reviewed by Chrissy Carroll, RRCA Running Coach and USAT Level I Triathlon Coach. This is for informational purposes only and should not be construed as training advice. Consult a doctor prior to beginning any new exercise program.

What is anaerobic running?

Anaerobic exercise is any activity that is done at an intensity where your body must produce much of energy for your muscles without oxygen (an = without, aerobic = requiring oxygen). It does this through glycolysis – breaking down stored glucose to produce energy.

Anaerobic workouts can include heavy weight lifting, sprinting (such as during a run or bike ride), HIIT (high intensity interval training) workouts, plyometrics, and other such intense activities.

In running specifically, anaerobic workouts could include:

• Timed interval training
• Hill sprints
• Fartlek workouts (unstructured intervals)
• Short track intervals (i.e. 200 meter or 400 meter repeats)
• VO2 max intervals

These exercises differ from predominately aerobic activities like comfortably-paced running, biking, swimming, and dancing, because those moderate activities rely on the body’s ability to produce energy using oxygen. You can do those aerobic activities much longer because you are able to use that energy system.

It’s important to note though that during any workout, there may be energy produced by both aerobic and anaerobic energy systems. It is not an exact either/or situation.

Examples of anaerobic running workouts

Below are some examples of specific anaerobic running workouts – like those you might see in a training plan. Note the interval portion is where the anaerobic running takes place; the warm ups, cool downs, and recovery are all aerobic running.

Short Track Interval Example: 6×400 at best sustainable effort pace

• Warm up for 10 minutes with a comfortably paced jog.
• Do 6×400 meters at your best sustainable effort, with a 400 meter walk or jog between each.
• Cool down for 5-10 minutes with a comfortably paced jog.

Timed Interval Training Example: 1/1 running

• Warm up for 10 minutes with a comfortably paced jog.
• Alternate between running 1 minute hard / 1 minute easy for 20 minutes.
• Cool down for 5-10 minutes with a comfortably paced jog.

Hill Sprints Example: Short Steep Hills

• Warm up for 10 minutes with a comfortably paced jog on flat(ish) terrain.
• Find a hill around 100-400 meters long that is on the steeper side (around 10%+ grade)
• Sprint up the hill, jog down the hill
• Repeat 6 times
• Cool down for 10 minutes with a comfortably paced jog on flat(ish) terrain.

Fartlek Example: Mailboxes

• Warm up for 10 minutes with a comfortably paced jog.
• Sprint to the next mailbox.
• Recover for 3-6 mailboxes (you can mix it up).
• Repeat, alternating sprinting and recovering, for 20-30 minutes.
• Cool down for 5-10 minutes with a comfortably paced jog.

Athletes can adjust the length and intensity of anaerobic runs based on individual fitness level, injury history, goal race distance. (More on all these below).

Benefits of anaerobic running

While there are various benefits to anaerobic running, here are a few of the most notable:

Works different muscle fibers – Slower aerobic workouts recruit more slow-twitch (Type I) muscle fibers. These fibers are smaller with lower force production, but are more resistant to fatigue. Anaerobic running, on the other hand, will recruit more fast twitch (Type II) muscle fibers. These are larger and can provide more force production, but fatigue more quickly. 

By incorporating anaerobic workouts, you help work these other types of muscle fibers. This also may be more conserving of muscle mass during training, as compared to aerobic workouts alone.

Enhances cardiovascular fitness – Any exercise is good for your overall fitness and cardiovascular system. But anaerobic running may provide some additional benefits:

• A study in Sports Medicine found that interval training led to a greater improvement in brachial artery function compared to moderate intensity exercise. 
• Another study found that there were greater gains in VO2 max following high intensity interval training.
• For patients undergoing cardiac rehabilitation, a review found that interval training was more effective in improving cardiovascular fitness compared to moderate exercise.

Improves speed – If you want to be a faster runner, you need to run faster in training (sounds much simpler than it is, of course!). There are some considerations here as far as the distance you’re training for, though.

For example, faster running workouts for a marathoner may not frequently branch into predominately anaerobic territory. A runner training for the 800 meter race will almost certainly have a decent volume of anaerobic running in their schedule.

However, either way, anaerobic fast running can help improve speed because it teaches the body how to run fast with quick turnover. Think “fast feet”; you have a stride where your feet are coming off the ground in quicker succession and without losing energy to as much ground contact. This is helpful at any distance.

Trains your body to use anaerobic energy systems – Let’s say it’s the end of a race and you are pushing yourself with a sprint to the finish. This is where it can become important for your body to have experience with fast running, both as far as turnover/form, and the internal energy systems that need to be working to provide the energy for that sprint. Anaerobic running workouts help with both.

Reduces the risk of chronic disease – Like any form of exercise, anaerobic running can help reduce the risk of diseases like diabetes and cancer.

Helps with weight management – Research has shown both aerobic and anaerobic exercise can help with weight management, alongside a balanced diet. (However, I much prefer athletes to focus on other measures outside of weight to assess their health and fitness).

Risks of anaerobic running

While anaerobic running can be a good addition to many training programs, there are some risks associated with it:

Muscular fatigue and tight/sore muscles – High intensity anaerobic workouts can lead to increased levels of muscular fatigue compared to steady-state aerobic exercises. It’s important to ensure you build in enough recovery time between high intensity workouts to account for this (and prevent overtraining). You can also use strategies like foam rolling or a massage gun to see if it helps with your recovery.

Injury risk – Anaerobic running workouts can increase the risk of injuries in those who are not prepared for them, or those who do too many each week. To reduce the risk of injury, be sure you’ve built a strong running base first before starting to add in speed work. Do not incorporate anaerobic running workouts if you have an injury that affects your running stride. In addition, always make sure to warm up properly before speed work.

Improper training type – The prior two risks are commonly known, but this third one is often forgotten. It’s important to avoid incorporating tons of anaerobic running workouts without paying attention to the nuances of your individual training goals.

For example, a marathon is 97-99% aerobic running. It’s silly to have tons of anaerobic workouts in a marathon training plan. You can certainly include speed work, like 5 miles at race pace or mile intervals – but these are still predominately aerobic. You wouldn’t include true anaerobic intervals frequently with marathon training.

However, there are certainly use cases – for example, some 200 meter intervals just to practice really fast running and get comfortable with turnover. These have a defined purpose; they just wouldn’t be used super often in a plan.

Should you do anaerobic runs – and if so, how often?

Let’s start with the general answer first. If you have built a solid running base, yes, it can be valuable to include some anaerobic runs in your training plan for the many reasons mentioned previously. (If you have not yet built a base, or are experiencing any type of injury that affects your stride, do not start incorporating anaerobic running).

For those who are not training for a particular race, you can decide how to incorporate these based on your preferences. Regardless, it’s best to limit high intensity workouts to no more than 2-3 times per week. It’s important to have rest days in between intense workouts to allow your muscles to recover and prevent injury.

If you are training for a race, then the recommendations get a bit more complicated. Generally speaking, the longer the race distance, the less anaerobic running that will be in your training plan.

For example, marathon training should focus heavily on aerobic running with some race prep speed work. You might include some anaerobic intervals to work on turnover and stride.

But an 800 meter runner will likely have far more short track intervals built into their training plan, with a heavier reliance on anaerobic running. Still, their training plan will have a blend of both aerobic and anaerobic running. (After all, an 800 meter race is still 55-65% aerobic).

In any scenario, usually around 80% of mileage is done at a comfortable aerobic base, and 20% might incorporate speed work (that could include both faster aerobic running or anaerobic intervals).

Overall, it’s important to adjust your anaerobic runs based on your training goals, preferences, injury history, fitness level, and more. There is no one-size-fits-all approach here. If you don’t feel comfortable developing your own training plans, I highly recommend working with a coach that can help structure a plan for your individual goals.

FAQs about anaerobic running

Here are a few more questions that tend to come up related to this topic:

The Bottom Line

Anaerobic running can be a great way to increase your speed and turnover while training for running events, or simply to improve your overall fitness level. However, it’s important to ensure that you have built a strong base before incorporating high intensity workouts. The right amount of anaerobic running will depend on your fitness level, goal race distance, injury history, and training plan. If you need help structuring a personalized training plan, consider working with a coach who can guide you through it.

• Author
• Recent Posts

Chrissy Carroll

Chrissy Carroll is a Registered Dietitian and USAT Level I Triathlon Coach. She specializes in sharing nutrition and fitness tips, as well as recipes, for runners, triathletes, and active women.Chrissy holds a Bachelor's Degree in Nutrition, a Masters Degree in Public Health, and is also an ACSM Certified Personal Trainer.

Latest posts by Chrissy Carroll (see all)

• Ricotta Breakfast Bowl with Pears and Cranberries - January 9, 2025
• The Best Cottage Cheese Egg Muffins (Even If You Hate Cottage Cheese) - January 3, 2025
• I Tried the Whirly Board at My Standing Desk – And Here’s Why I Love It - December 22, 2024