If you’re a crossfitter, chances are your cardio sucks.  It’s a harsh statement, I know, and I put myself in this category as well.  Crossfitters are pretty strong and mentally tough, with great anaerobic endurance, but they often neglect their aerobic conditioning.  This is likely the single biggest factor that is limiting your performance.  This article will discuss methods to increase your aerobic capacity, and still keep all your gainz bro.

There is a persistent myth that if you engage in specific aerobic conditioning work that you will become weaker.  To be fair, if you only did aerobic capacity work, or if you paired your lifting with conditioning incorrectly, then you could become weaker.  That being said, it is not particularly difficult to increase your conditioning without losing strength.

This program is designed to supplement your current crossfit programming.  I’m assuming that what you are doing currently is probably pretty good for crossfit performance. You need to continue on with it and simply add in these workouts to target your aerobic energy system specifically.

I do not recommend doing a ton of extra lifting, sprinting, or any other specific program in conjunction with this.  Your body only has a certain capacity to recover, and you can’t get better at everything at once.  Remember, if everything is a priority, then nothing is a priority.

Picking Your Poison 

There are numerous types of exercise you can use for this program including: running, swimming, rowing, cycling, airdyne, rucking etc.  You are only limited by your imagination, as you could conceivably pick any activity that can be done for 30 min or more.

With so many choices, how are we to know what is going to give us the most improvement?  Well, I’ll make that easy for you.  If you don’t have any injuries precluding you from running, then you should run.

If you happen to be a heavier athlete, or a little older, then you should probably pick airdyne.  If you are in the military then you could use rucking, otherwise I just don’t see the benefit for most crossfit athletes.

Someone’s doing this for fun?                                     Photo courtesy of Paul S. Martinez USMC

The Crossfit Aerobic Capacity Program 

This program is going to be two days a week, with a little extra work pre and post wod.  I like to call this work sandwich training.  Don’t get too excited, there’s no mayo involved here.

You’re going to sandwich your normal crossfit session with some aerobic conditioning before and after the wod.  There will also be two specific training days a week devoted only to conditioning, in this case running, which is the modality I recommend for most crossfitters.

If you substituted another modality for running, then use it, but make sure that the overall intensity and training duration remain close to what is programmed below.

Week 1 Running Plan 

This week is an introductory week, designed to get you used to the extra stress of running.  As a crossfitter, you need to be very cognizant not to make these cardio sessions too hard.

Week 1 Crossfit Running Plan
Week 1 Crossfit Running Plan

All the sandwich training should be at a conversational pace.  If you have a heart rate monitor, I highly recommend you wear it, and keep your heart rate in zones 2 or 3.  Click here to calculate your personal heart rate zones.

I can’t overstate how important it is not to go anaerobic.  If you would like to get a heart rate monitor you can check these dudes out.

Heart Rate and Fitness Monitors 

  1. Fitbit Charge 2 HR (Probably the most popular overall fitness device)
  2. Polar Heart Rate Monitor (Tried and true)
  3. Bluetooth HR Monitor (this is a monitor that pairs with an app on your phone)

*Amazon Affiliate Links

The long run at the end of the week is also at a conversational pace, in zones 2 and 3.  The sprints are going to be pretty difficult for those who are not accustomed to this training.

Because they are EMOM style, this will not be a true max speed sprint, which should not be attempted without extensive preparation.  Each interval should be completed under 20 sec if possible, and ideally between 15-18 sec.

Week 2 Running Plan

Week two will see an increase in sandwich training length.  It will also increase in duration for the long distance run, and the number of reps for the EMOM sprints.

Week 2 Crossfit Running Plan
Week 2 Crossfit Running Plan

The sandwich training may seem a little strange to some, but I have found that it works very well for a variety of reasons.  It warms you up for your crossfit session very well, and it also promotes clearing of metabolic waste products after the session, which will have a big impact on your ability to recover from your wods.  It’s also a time efficient way to get more aerobic training in.

Week 3 Running Plan

This week will continue to see increases in the sandwich training, and the difficulty of the end of the week running sessions.  These sessions are designed this way to really target the areas crossfitters need.  We don’t spend much time working our aerobic fitness, or in our near sprint speed running.

Week 3 Crossfit Running Plan
Week 3 Crossfit Running Plan

You can see that we are doing a lot of running by this week, and you should  be fairly accustomed to it by now.  Pro tip, wear some earbuds for those long runs and it will reduce the perception of fatigue during the run, and generally make it a little more pleasant.

Week 4 Running Plan

This week is going to be the most miles you have in the 8 week training plan.  It can be rough, but just stick it out.  By now you should be feeling the effects of the extra aerobic capacity.  Your wod’s should be feeling a little easier and you should be able to go a bit faster than you normally would.

Week 4 Crossfit Running Plan
Week 4 Crossfit Running Plan

There is light at the end of the tunnel.  We will be switching routines next week, so don’t think that you will be running for 2 hours in a few weeks.  I’m not that cruel, or am I?

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Week 5 Running Plan

In week 5, we have finally leveled off with our sandwich training.  It will not increase from here, but we have changed our running workouts at the end of the week greatly.

Crossfit Running Plan
Crossfit Running Plan

You’ll notice that the long easy run is gone, and a tempo run has replaced it.  A tempo run is designed to practice running a little faster than your aerobic capacity will allow.

Your body will need to produce lactate to augment the energy production from your aerobic system.  This is beneficial because it ensures that you are using 100% of your aerobic system, and it allows your body to get better at clearing the waste products from anaerobic energy production.

This run is at a rate of perceived exertion (RPE) level 7.  Which is generally described as comfortably hard, but not max effort.  Likewise, the 200m intervals are at the same level of exertion.  For these 200m intervals you should rest as much as you feel necessary to continue on at the desired RPE.

Week 6 Running Plan

In this week, our tempo run gets a little longer, and the rate of exertion increases to an 8.  This is going to feel hard, but something that you could maintain for a half hour if you had to.

Week 6 Crossfit Running Plan
Week 6 Crossfit Running Plan

The sprints are going to be the same as last week with the exception of some additional intervals.  Again, rest as you need to complete the next interval at the desired RPE.

Week 7 Running Plan

This is the hardest week in terms of intensity.  The tempo run is very close to all out effort, and the sprints are going to be fairly tough as well.

Week 7 Crossfit Running Plan
Week 7 Crossfit Running Plan

This is going to be the last week before our testing week, week 8.  By now you should be feeling much faster on your runs and your wod performance should be much higher.

Week 8 Running Plan

You’ve made it to the final week.  We are keeping the sandwich training and are leaving our time trial to the end of the week.

Crossfit Running Plan
Week 8 Crossfit Running Plan

I recommend completing the 5k time trial on a track or on a level course.  Hill runs are fine for your other training, provided they aren’t pushing you to go anaerobic when you shouldn’t be, but for this kind of running test you need to find a flat course.

I also recommend going to your local high school on the weekend.  Most leave the track unlocked for the community to use, and if you decide to jump the fence you will sure score a hell of a PR when the cops are chasing your ass for trespassing.


If you like carbs, then this is the program for you.  For running, there is no way around eating carbs.  I know a lot of crossfitters think that they will get fat and their performance will suffer, but that’s just flat out wrong.  Read this article covering carbohydrate research for crossfitters.

For protein, I recommend eating at least 1 gram per pound of lean mass, up to 1 gram per pound of bodyweight.  Any more, and it is like being stored as fat.

Fats should hover around 60g for the lighter athlete, up to 100g for a heavier athlete.  Overall I recommend tracking your food intake with a free app called My Fitness Pal.   Ideally you should be eating enough calories to cover all your training.  This is a performance enhancing program, not a weight loss one.

If you are really an over achiever, you can track your exact mileage using a running gps (Fenix 3 HR from Garmin Recommended), and use this formula to figure exactly how many carbs should add to your diet.    

You can also use a free app called Map My Run to track mileage and other running related variables.


Bodyweight x .66  x miles per day  = extra calories needed / 4 = grams of carbs

Here’s an example: 200lb male x .66 = 132 x 3 miles = 396 cal / 4 = 99g carb


Don’t be afraid to experiment with your macronutrient requirements, but do not skimp on the carbs if performance is what you are after.

Final Thoughts 

I know many of you are secretly thinking that you will waste away to nothing if you run this much, and you will, if you don’t eat enough, or pay attention to recovery.

Remember the goal of this program is to enhance your performance through increasing your aerobic capacity.  As long as you are eating appropriately, and still busting your ass with your lifts, you will not loose any appreciable amount of strength.  Don’t skimp on the food, keep your fitness goal in mind, and pretty soon you will be crushing your metcon’s.