If you have any physiology, performance, or nutrition related questions, email Ben at ben@yourgroupride.com.
Does nutrition really matter?
There are some people who think carrying around a bottle of filtered water all day make
them healthy. This practice may make the person healthier than if he/she did not do it,
but it does not necessarily make them “healthy” if they also smoke a pack of cigarettes a
day. On the other end of the spectrum, we all have that friend who eats (or even drinks)
whatever he/she wants and still does well on the bike. However, some people are given a
great set of genes, and no matter what they do, they will still do well. Doing well despite
a poor diet, however, does not mean that the person is doing as well as he/she could.
This particular column will give you a little perspective on the importance of nutrition for
cycling performance. Although nutrition by itself will not make you better than you
really are, without proper nutrition, you will not live up to your potential.
The basics of human adaptation are that you stress the body, the body senses the stress,
and the body takes appropriate steps so that the next time the stress is imposed, the body
is better suited to deal with the stress. The “appropriate steps” the body takes has to do
with making proteins. For instance, if you perform a bout of weight training, your body
makes proteins in the muscle that are better suited to generate force so that you can move
that weight easier next time. This example of course is why your muscles get bigger with
weight training. Not so obvious are the proteins your body makes after a long training
ride since there is no physical appearance of those proteins. The proteins your body
makes after a long training ride are the ones that make your muscle better suited to use
oxygen for energy production, e.g. mitochondrial proteins, enzymes, and cell
transporters.
The application of adaptation to exercise training has been termed the overload principle.
What the overload principle states is that one must apply an appropriate stress to the body
so that the body is not understressed, thus providing no stimulus for adaptation, or
overstressed, causing failure and overtraining. The stress must be specific to the goal
you are trying to achieve and designed for the individual person. “Specific” has many
levels of complexity in cycling – such as we do not go running (regularly) to get better at
cycling, to doing 5 second jumps rather than 3 hours of easy riding to get better at
criteriums. Individuality refers to the fact that all of us adapt to stress differently as a
result of our genes, and therefore what might be right for us may not be right for another
person.
There is one more component of the overload principle that most of us know all to well
and that is reversibility. What reversibility means is that if a stress is not applied for
some time, the ability to deal with that stress will go away; or said another way,
reversibility refers to detraining. A good question is why does the body detrain? Why do
we have to go through all the work of building up resistance to stress again? The answer
has to do with the proteins the body makes to help us adapt to stress. These proteins have
to be built up and broken down to stay in good working order. The process of building
up and breaking down proteins takes a lot of energy. In fact, while resting the making of
protein is the single largest consumer of energy in the body. Therefore, the economics
becomes quite simple, if the body does not a protein for a little while it gets rid of it sothat it does not waste energy sustaining it and can focus its resources on other proteins
that it does need.
As mentioned, the body “senses” a stress. The means by which it senses is beyond the
scope of this column. What is important is that the sensing of a stress sets in motion a
series of events that makes proteins. You may then ask how the body knows what
proteins to make? The search for the appropriate pathways and what turns them on is a
very active area of cellular biology research. For the purpose of this column, though, we
will call these pathways “signaling pathways” because a sensor turns on the pathway and
signals only the correct proteins to be made. For example, when people go to altitude to
train, a sensor detects that there is less oxygen and turns on signaling pathways that make
proteins that will help deliver more of the oxygen that is available. The important point
here is that the body will always sense these challenges and put in to motion the signaling
pathways to take better adapt to the challenge. Specific to cycling, the time spent on the
bike doing long slow rides, sprint workouts, and intervals are the stimuli that are sensed,
and turn on signaling pathways that tell the body which proteins to make so that we may
do those specific tasks better next time.
I stated in the introduction that this column was about nutrition, but I have not yet
mentioned it. Therefore, I want you to think of the processing of building a house.
Suppose you visit the architect and have your dream house drawn up on blueprints. You
then buy the perfect plot of land, stake your lot, and hire all the best contractors. Finally,
the big day comes, the ground is broken and the crew gets to work. Now imagine that
you only had enough money to buy second-rate construction materials, how close will
that dream house really come to its potential? Will it really be a dream house with
inferior building materials? This analogy is really quite simple and obvious, the blue
print is your training plan, the contractors (translates blueprints to a house) are your genes
(translates training stress to proteins), and the construction material is the nutrition
components that build the body’s structures.
I was careful to state above that the signaling pathways tell the body what proteins to
make. However, in the absence of the appropriate building blocks, the body can’t
actually make the proteins. In other words, training sets in motion an adaptive potential.
To take advantage of the potential, amino acids (from protein) must be provided to build
the proteins, and energy (primarily from carbohydrate) must be provided because of the
energy it takes to build proteins. As I write this, my first thought is that people will take
away that eating lots of protein is the most important nutrition modification you can
make, which is wrong. Yes, eating protein is important, but for the endurance athlete
eating enough carbohydrate is still most important. Since the body uses up energy during
exercise, you need to replace it after you are done or you will not have enough energy to
make the proteins you need in your body to adapt to the training. In fact, if you don’t
have enough energy, your body will break down proteins that you may need without
replacing them, because at that point in time, having energy to sustain body function is
more important than maintaining more protein. Interestingly, scientists have recently
discovered that the amount of energy in the cell is one of the “signals” that determines
what proteins are made and not made. Further, on a day-to-day basis people need toconsider the so-called micronutrients, also known as vitamins and minerals. These
nutrients are important because they make sure all the pathways in the body are working
properly. Therefore, having a well balanced diet is important to make sure that all the
metabolic pathways are working smoothly. The take away message is that by having a
well-balanced diet and providing energy and protein around your training provides the
high-quality building materials and workers to take advantage of the adaptive potential of
your training.
In summary, nutrition is important, and just as nutrition alone can not make you a great
athlete, training without proper nutrition will not make you as good as you could be. I
have to give one more word of caution here to fend off a mixed message – although
proper nutrition is important, more is not always better. In fact more (such as found in
“supplements”) can often be detrimental. In a future column I will address the “why”
behind why more is not better.