Stronger. Faster. These are words that we all want to use when describing our progress. This is another look behind the scenes that will explain how we as a staff will get you there.
This is part 2 of a two part blog where we explain some of the “whys” and science behind implementing rest periods in our WODs. You won’t see it every day, but more in frequency than the past. If you missed the topline overview in part 1 from Coach Ashley, it can be found HERE.
For a deeper more technical dive into the science, here’s words from our Director of Programming and Education, Coach Matt:
Why All the Rest? PART 1: An introduction
Why all the rest seems to be a popular question or concern around the gym lately as this is typically not what you have seen as of late.
I’d like to start by bringing your attention to probably the most famous crossfitter of all. A man who is not known for being a jack-rabbit, but a tortoise. A man who, operating in this manner, has claimed the title of 2nd Fittest on Earth once, Fittest on Earth four times in a row, and now Captain of the reigning affiliate cup champs 2 years in a row, Rich Froning. He is known for picking a pace and not slowing down and sometimes speeding up. The tortoise comparison is more about pacing and sustainability and less about pace because it is commonly said that “Rich Froning’s 90% is better than your 100%”. This is due to his amazing aerobic base. So the takeaways from Rich Froning are that pacing (smart athlete) is important and you need an aerobic base (his body knows how to use oxygen well).
So now you might be wondering how do I build these tools of titans in CrossFit. Let’s first address building an aerobic base. Crossfit is still very new in the world of strength and conditioning. But sports like running, biking, and swimming have a long history of building aerobic bases. So they tables of work to rest for these sports was adopted for the sport of crossfit. Now tweaks have to be made as CrossFit is mixed modal (different movements) but from the tables we have the framework of work to rest ratios for building and our aerobic system. One of the first pioneers of this methodology was Opex (formerly OPT, the company of the first crossfit games champion James “OPT” Fitzgerald). So when you hear Opex or OPT thrown around, this is to what we are referring.
Now looking at learning how to pace. Well the natural structure of the aerobic system works lends its hand to pacing. If you are doing multiple sets on limited rest and we want the efforts to be sustainable (most of the time), i.e., you need to pace. Learning how fast you can push for a repeated 30, 60, or 120 second efforts sets you up to better learn how to pace for a 10 minute effort.
So hopefully now you are at least open to considering the benefits of both pacing and an aerobic base.
Why All the Rest? PART 2: Aerobic Training
First we begin with looking at some background of CrossFit in general.
CrossFit’s prescription for fitness is constantly varied functional movement at high intensity. Right now let’s focus on the high intensity. First off, intensity is seen at work for a given time domain, if you do more reps in an AMRAP, then you have done more work and therefore had a higher intensity. Intensity in this definition is not based on whether you ended up dying lying on your back but simply on how powerful you were.
Let’s familiarize ourselves better with what aerobic work is. To put it simply, one of your body’s most powerful way to produce energy burn sugars and a byproduct of burning sugars, pyruvate, combines with oxygen to give you energy. If your use of oxygen can keep up with using that pyruvate, then we call it aerobic. So we can see that as long as you keep breathing, and oxygen is available, this work is sustainable. But sustainable also depends on time domains and level of intensity for which we are training. A quick aside with this is that oxygen consumption is directly related to calories burned.
There is a negative correlation between power output and time domain (i.e., the longer you are going to do a task, the lower the power output must be). So if we are based upon higher intesity training, not only does a longer time domain cause a lower power output but to quote an article from the Poliquin Group:
“Steady-state training makes the body as efficient as possible so that you will use the least amount of oxygen and energy to perform the greatest amount of work. It’s very metabolically efficient, which is not our goal when you want to lose fat or build muscle. Second, low-intensity aerobic training such as walking leads to the loss of lean muscle mass over time so that your resting metabolic rate goes down and you burn fewer calories However, if you train longer interval repeats with very short rest periods that don’t allow for full recovery, you can produce a significant metabolic disturbance. This can also deplete stored glycogen [sugars], which can aid with fat loss since any carbs you eat after such a workout will replenish the muscle stores rather than be turned to fat.”
The aerobic intervals that we see a few times a week play into the aerobic interval training described in the excerpt using the guidelines found with energy system guideline tables as it applies to CrossFit.
Lastly, to touch the aspect that power output and how you feel afterwards are not directly related. If you go out too hot where your oxygen cannot keep up, then you build up and excess of that pyruvate, hydrogen atoms (likely cause of burning), and lactate (when those two combine) which can interfere with muscle function. So going out too hot will not only make you less comfortable with an increase in lactate combined with an oxygen debt but also your muscles potentially misfiring because of all the waste present. Hence the beauty of pacing and medium intervals with short rest tends to do a good job of teaching this. References: http://main.poliquingroup.com/ArticlesMultimedia/Articles/Article/1151/The_Truth_About_Cardio _For_Fat_Loss.aspx
Why All the Rest? PART 3: Anaerobic Training
So far we have touched on interval training as it applies to the aerobic training but we also do anaerobic intervals (the short all out sprints). The anaerobic system is what burns the sugars and is can produce a lot energy but it only lasts so long. When training this system, it is all about the power output, i.e., reps/speed, which makes it anaerobic, not just the length of the exercise. You can walk for 90 seconds and it won’t be anaerobic (hopefully). We see this training coupled with the long rest intervals.
The rationale behind this is the same as with aerobic work, to keep the power output high. But because this system has a limited fuel source, as it runs on the glycolytic stores in the muscle itself, replenishing these stores take more time than simply making up an oxygen debt as is the case with aerobic training. Depending on how powerful the athlete is, it could take 2-5 times as long or in some cases hours to make the effort repeatable. In some cases, 1 min Max Assault Bike Calories will take some at least an hour to recover from. So the long rest is important to keep the training session anaerobic instead of it turning into an aerobic session.
Why does it matter to train this system? As it applies to CrossFit, this is how you sometimes finish out a workout with an anaerobic sprint finish. So this kind of training works on developing the capacity to finish strong. But beyond that, anaerobic training is valuable in itself. I can’t put it better than the Poliquin Group puts it here: http://main.poliquingroup.com/articlesmultimedia/articles/article/1307/nine_reasons_to_prioritize _anaerobic_training_over.asx
Essentially anaerobic work builds you up, makes you strong, builds a better hormone profile, and it still has the benefits of aerobic training.
What if I am not powerful? It is simply a matter of fact that to train this type of system, you need to be powerful (a prerequisite amount of absolute strength). On these days, you should still go as hard as you possibly can. Every effort needs to be maximal but it might be that full rest in not needed. Accounting for this, we see EMOMs sometimes on these days. Powerful athletes get the longer rest necessary to recover while less powerful athletes get shorter rest intervals (because they took longer to do the work) as that is all they require. If we are on a day with a fixed rest and you feel like the full rest in not necessary for you to repeat the fastest effort possible, cutting down the rest is acceptable because that is a better prescription for you.
Why All the Rest? PART 4: Why not anaerobic all the time?
From part 3 we learned anaerobic training looks like it is superior to aerobic training, and it has all the benefits of aerobic training and more. You might find yourself wondering why don’t we do that all the time?
Well fortunately or unfortunately depending on how you want to look at it, anaerobic training is quite potent. This type of training also takes a big hit on the central nervous system (CNS) and training it too frequently can lead to CNS fatigue.
But this doesn’t apply just to anaerobic days. We also touched on how you can push hard at the end and go anaerobic. Doing this every day can lead to CNS fatigue. Athletes sometimes describe this as just having that extra gear in a workout. The programming does attempt to take this into account and by workout structure and movement selection dampeners can be put on workouts but also understanding that showing up and hitting it at 85-90% keeps you coming in the gym consistently.
Consistency beats anything you can do in one day or one month. If you show up to the gym 4 days a week and get a half percent, 0.5%, better each day. You will be 2.82 times better in 1 year. Charles Poliquin likes to advocate kaizen, consistently better in small ways.