The 2-mile run might be a good fitness test for someone running a 2-mile race or even a 5k, but there are better options for soccer. In this article, I explain the energy systems, muscle fiber types, and “fitness tests” for soccer.
Exercise Physiology: a very brief introduction
Our bodies have three energy systems. The first one is immediate and fuels short bursts of energy like Olympic weightlifting and golf. The second one is considered short-term and fuels activities that last from about 10 – 60 seconds, such as soccer, lacrosse, and basketball. The third energy system is long-term and fuels activities like marathons or rowing.
Hang on before you ask why soccer falls into the second energy system if it is a 90-minute game.
All three energy systems overlap and soccer, like several sports, utilizes all three systems.
Yes, the 2-miler would fall into the long-term energy system. And yes, a soccer game lasts 90 minutes which is over 2-3 minutes.
But, the 2-miler trains slow-twitch muscle fibers that are good for long, steady-state cardio. Soccer utilizes primarily fast twitch muscle fibers and is not a long, steady-state cardiovascular sport.
Soccer involves explosiveness, jumping, cutting, changing direction, agility, quickness, speed, or other buzz words that do not mean steady state cardio. The difference between steady state cardio and those buzz words is that every time you change direction, make a run, or chase a defender, you are relying on energy system two and fast twitch muscle fibers.
Let’s go into the systems and muscle fiber types a little bit deeper to explain this more.
Energy system 2 is called the glycolytic energy system. The glycolytic energy system runs on glycogen (glucose stored in your body). This means that when your body starts to fuel this energy system, it breaks down glycogen for fuel. Breaking down glycogen is a process that creates byproducts. As you continue to exercise, those byproducts build up in the muscle until it becomes too acidic to keep up a high intensity, so you start to slow down. An important thing to keep in mind is that this energy system does not need oxygen to be present in your cells. Instead, you rely on the carbohydrates in your body as fuel.
*Side note: Carbohydrates are sugar. Sugar is glucose. Glucose is in the bloodstream, so your body can access it for quick fuel, but it won’t last too long. When glucose is stored in the body, it is glycogen. This takes a little longer to break down and will last longer (Hint: this is why you should eat plenty of carbohydrates in all of their forms).
The third, long steady-state cardio system is called the aerobic energy system. The aerobic system works similarly to the second, except when glycogen breaks down in your cells, oxygen gets involved.
The aerobic system produces the same byproducts that the glycolytic, or second, energy system does. But, rather than build up in the muscle, the byproducts combine with oxygen and create other molecules that are sent to other cycles. Sending the byproducts to these other cycles produces more energy, and that allows this energy system to almost, kind of/sort of recycle.
This system can utilize fats and carbs for fuel. It will even utilize protein if fats and carbs are not present. This means that if you do not eat enough carbs and fats, your body will find protein so you can keep going.
*Side note: We do not want to use protein for fuel. That actually breaks down your body too much and will hinder your gains.
Muscle Fiber types
(insert attached image here)
In the first picture, the long-distance runner has mostly Type 1 muscle fibers (dark pink/salmon). Type 1 muscle fibers last long but do not provide explosiveness. If you trained only Type 1 muscle fibers, your ability to jump, change direction, sprint, cut, and chase down the ball, would not be sufficient for soccer.
Running 2 miles trains only the Type 1 muscle fibers. The middle distance runner has a mix of Type 1 and Type 2 (light pink/salmon) muscle fibers. You have multiple types of Type 2 fibers, but for the sake of this article, we only need to know about Type 2A.
The Type 2A muscle fibers are used for jumping, changing direction, cutting, sprinting, and chasing down the ball. We can train these muscle fibers by training the glycolytic energy system.
*Side note: The other type of fast-twitch, Type 2 muscle fibers are Type 2B. These are trained in the first energy system, which is not mentioned in this article because in order to keep things as simple as possible. You do use the first energy system in soccer, but this energy system is mostly reserved for power sports like Olympic weight lifting, sprinting short distances, or things that will allow short bursts with plenty of rest. When training for maximum speed, you will train this system (which we will get to shortly).
For soccer, we use Type 2A mostly. We will utilize the other ones. But by running 2 miles and only training the type 1 fibers, we will actually end up making the Type 2’s weaker.
A quick recap before moving on:
All energy systems, including the first one, are used in soccer. The reason it is important to stress the second, or glycolytic system, for soccer players is that soccer is not a steady state cardiovascular sport, nor is it a power/explosive sport. It is 90 minutes and utilizes explosiveness, yes. But, since soccer does not have minutes of rest (which the first energy system needs), and is not performed at one steady state for all 90 minutes, the most efficient energy system for the demands of soccer is the glycolytic energy system. And included in this training is being able to recruit your type 2A muscle fibers.
Now let’s talk about assessments that are better than the 2-mile run for soccer. Notice that I said assessments. “Fitness tests” are not even necessary. That does not mean that putting in the work during the off-season is not important. I would not be a strength and conditioning coach if that was what I thought.
Instead of fitness tests, watch your players practice. Do they go 100%? Are they still going 100% in the last drill? Now you know who is in shape.
If my spot depended on it, I could run 2 miles faster than you. That is more a mental game than if I am in shape for my season. If you want to assess the mental game of your players, that is a separate article.
Here are some assessments that I use to assess the speed of players:
- The 20-yard dash tests explosiveness and the first step, aka how fast can you get fast.
- The 40-yard dash is how fast you can get.
These utilize the first energy system, so you should make sure you are giving your players at least a 1:6 work: rest ratio. But, if you want to test true maximal speed, then you should give them at least a minute rest to let the first energy system fully recharge.
- Flys – Fly runs are like dashes, but rather than start at a dead stop, you are jogging and then go into a sprint.
Again, these will utilize the first energy system, so still give ample rest.
- Beep Test (aka yo-yo intermittent): I don’t use this one on my players, but I included it because it is a better option for soccer than the 2-miler.
Once I get data on these and a few other assessments, we start a training program. Their numbers get better over time because we train their explosiveness and speed and predominately hang out in the first two energy systems. We do not run 2 miles. Nevertheless, they show up prepared and in shape for soccer season.
It is important to be in shape for the season. It is important to train the right energy systems and the right muscle fiber types for your sport. It is not important to do fitness tests on your players that do not involve the right energy systems or muscle fiber types. Especially when they are getting conditioning in all of the practices and camps, they attend throughout the summer. Yes, you can still give them things to do on their own to help them prepare for the season – just not the 2-mile run. Instead, it is worth the investment to hire a knowledgeable strength and conditioning coach who knows the systems and muscles and who can safely progress them to peak performance during their season.