Why “Rx” Isn’t Always Best (ft. Coach Marissa)November 14, 2016
Train Smarter, Then Harder
“Rx Isn’t Always Best”
As an athlete most of us have been there. Standing in front of the whiteboard you
anxiously listen to the coach explain the “WHAT” of the workout and an
explanation of Rx weights/standards. This is the point where your inner-coach
can show up and you start internally debating over what weight to use and
sometimes the reason you miss the “WHY” we are asking you to train this way.
Everyone wants to be able to do do a workout Rx, but sometimes doing a workout
just because you want to hit the little blue button means you might be missing the
point. Strength and the lure of a heavy barbell can often be the first measure of
progress a novice athlete gravitates toward, however our goal in programming is
achieving peak functional fitness. Functional fitness involves training the body for
daily life activities. These exercises equip your body to handle real-life situations.
With that in mind, let me expand on how that factors into how we train.
The Crossfit view of fitness uses three different standards for defining and
measuring fitness. The first is based on the ten general physical skills widely
recognized by exercise physiologists: cardiovascular/respiratory endurance,
stamina, strength, flexibility, power, coordination, agility, balance and accuracy.
A training regimen is only as effective as its ability to show
improvement/competency in each of these ten skills. Focusing in only one aspect
of these skills will result in deficits in overall fitness. An athlete that can deadlift
a #500 bar can easily boast of his strength. However, if he can’t run 400m
without fear of collapsing he can’t say much about his level of functional fitness.
This athlete could help lift a tree off of you, but if you needed him to carry you any
sort of distance to get medical care..your fate is probably in jeopardy.
The second standard is based on performance of any and all athletic tasks,
presented in an infinite variety of combinations. This is where the “constantly
varied” tenant of Crossfit comes into play and why you will see every conceivable
task, rep scheme, rest period and order of exercises when we train. We strive to
keep the stimulus broad and challenging. This is why it is important to work your
weaknesses, be consistent in training and not just show up on the days we are
doing something you are really good at. Your ability to do a pullup, knock out a
dozen push ups (meeting the standards of movement) is just as important a factor
in fitness as how heavy your squat is and our goal is to train you in a manner that
builds skill and efficiency across the board.
The final basis of how we measure fitness has to do with the energy systems that
drive all human action. The body has three metabolic pathways (main energy
systems) that are used to provide energy for all human action: phosphagen,
glycolysis, and oxidative systems. Energy is derived from a molecule, adenosine
triphosphate (or ATP as we learned in Biology). Training in these systems help
replenish ATP, which in turn increases our work capacity. The phosphagen
system is the predominant energy system used for all out exercise lasting up to
about ten seconds and is active at the start of all exercise regardless of intensity.
Max lifts in the 1-3 rep range or sprints are good examples of training in this
system, but due to the limited amount of stored ATP in the muscles fatigue will
occur rapidly. This is why rest periods are sometimes programmed in with the
workout or why we stress the importance of resting in between sets on strength
training. The second energy system is glycolytic and dominates moderate
powered activities. Glycolysis is the breakdown of carbohydrates (either stored in
the muscle or delivered in the blood, to produce energy. This system is activated
when an activity lasts anywhere from :20 to 3:00. Fran is a benchmark workout
that is intended to test the glycolytic energy system. An athlete that can complete
forty five #65 thrusters might feel justified in attempting to Rx Fran, but if she
needs 12:00 to accomplish it has missed the intended stimulus behind this
workout and turned it into a strength session. Doing so will make you stronger at
thrusters and pullups, but the goal of Fran is speed. Lastly the oxidative (aerobic)
system is the primary source of ATP at rest and during low intensity activities.
The oxidative system primarily uses carbohydrates and fats as sources to create
ATP. As the intensity of exercises increases your body uses mostly carbohydrates
as an energy source. This energy system is used mostly when activity lasts longer
than 2:00 and is relatively lighter in intensity. Those 5k days we all love would be
a good example of training in this system. Which system is being used to supply
energy for training is determined primarily by the intensity and secondarily by the
duration of the exercise. Because Crossfit is constantly varied, we program in way
that targets all three of the systems in order to elicit the highest overall level of
As Crossfit founder Greg Glassman has said … “The magic is in the movement, the
art is in the programming and the science is in the explanation.” Coaching
sometimes requires leading athletes in a different direction than they want to go,
hopefully reading this helps explain the bigger picture we are looking at when we
do so. We are always going to push athletes to train at an intense level, but the
goal is to get you to train smart, and with an overall purpose as well. I also can’t
go without saying, achieving the full benefits of training also requires attention to
your nutrition and recovery. Should you have any questions on how to do this,
please contact myself or any of the coaches on staff at River to River Fitness.
See you at the box,
Crossfit L1 River to River Fitness