For the recreational fitness enthusiast, CrossFit and Endurance sports are two completely different modalities. The general belief is that “CrossFit makes you bulk up and that doesn’t help long distance runs/ bike rides/ swims”. To be a good at marathons you gotta practice marathons, right? Not necessarily.

With the recent expansion of CrossFit world-wide, High Intensity Interval Training has also been re-invented. Most people will likely be able to tell you that CrossFit workouts are “intense, but short”. And, although that is not always the case, those workouts became a trademark of CrossFit. But why is that?


Because it works.


It doesn’t just work for the 20 year-old looking to get jacked. It works for the high school tennis player, the soccer mom and the retired athlete. Different people, different goals, but the result is the same: becoming fitter. The same applies for the endurance athlete. You can become better at long distance activities by doing short and intense workouts!


Now the fun part, I get to convince you CrossFit will make you a better long distance athlete.


As talked previously, the human body uses 3 energy systems to deliver fuel to our muscles. If we only practice one of them, in this case the oxidative pathway (aerobic exercises), we only improve one of them. But in races, as in life, you will not only use one system to operate on. If at the end of the race you need to sprint, or there is a steep hill ahead, you need the other systems to jump in and give you a boost. You won’t be prepared for that if you only train in your oxidative zone.

Your muscles have fast and slow twitching fibers. Training only long distance will greatly improve the slow twitching fibers but will do little to the fast twitching fibers, and vice-versa. Hence why marathoners are not good at power movements, like back squat, and powerlifters aren’t good at long distance events. One of the many reasons why that is, is that they lack the muscle fibers to accomplish the task. Why it is good to train both types of fibers, along with what I said on the paragraph above about needing the extra boost on races, is that when one type starts to fatigue, the other takes over.


If you have no fast twitching fibers you have no backup.


Another factor that affects long distance athletes is body composition. It is a benefit to be “lean” when doing long distance activities since you’ll be carrying your own body the whole way through. High Intensity Interval Training is proven to give the best bang for your buck regarding burning fat and gaining muscle, but most importantly, in CrossFit specifically, we practice a lot of body weight movements and get adapted to move our bodies long ways, even with the added muscles. It’s like getting two birds with one stone, except that in this case it’s more like 5 birds and one stone.

Lastly, if you talk to a triathlon athlete they will tell you to find out  two important pieces of information about yourself: VO2max and Lactate Threshold. The former refers to how much oxygen your body is capable of pushing to your muscles when you’re fatigued. The latter refers to how hard you can push yourself before lactate starts building up in the bloodstream. Lactate is a substance that derives from the muscles during intense exercise. It makes us feel pukey and causes us to cease the activity.


If you ever did “Fran” you know what I am talking about.


CrossFit has been shown to be one of the best activities to build up your VO2max, while elevating your Lactate Threshold. A lot of this improvement comes for the anaerobic work done in classes. It is a lot easier to reach the your fatigue point and practice working under stress in High Intensity Interval Training than by doing long runs. So if I tell you I can get you to the same point of fatigue you feel 3 hours in a marathon, in a 20 minute workout, which one would you choose to use in training? Which one would work your VO2max, Lactate Threshold, slow and fast twitching fibers and multiple energy systems?


Become an ATHLETE and your endurance will improve.


Overall, many endurance athletes have started doing more anaerobic work because we have learned about the benefits of it. Obviously, there are benefits in doing long distance workouts, specially for endurance athletes, and we do not neglect that area. A few times a month we do practice long runs and work on our aerobic system. But if you want to see gains in your aerobic capacity, add some HIIT workouts in the mix and you will feel much better about your “engine”.


by Coach Matt