Energy System Development

Overview

This article breaks down how energy is used throughout your body, the body muscle fiber types, the energy systems of the body, and the components involved in conditioning.

How do we create energy?

What is the energy currency of life? Adenosine triphosphate, also known as ATP. ATP is the only energy currency your body uses for most of its basic functions, and it is created by the cells through three different energy pathways (phosphagen (or ATP/PCr), anaerobic glycolysis, and oxidative(aerobic) system), dependent on the intensity and duration of your workouts. If your goal is to lose weight, run a 5k or increase muscle growth, it's important to actively train all of these systems. That will allow you to burn fat while building muscle, which can also lead to a faster metabolism and a better quality of life.

Questions you may have

Which system should the majority of your workouts target? How do you train effectively and efficiently for each system?

Types of Muscle Fibers

Before we go into the energy systems, let's discuss the different muscle fiber types found in the body. The human body has three muscle fibers. Each body is special in its distribution of these muscle fibers. This goes hand in hand when looking at body types (ectomorph, mesomorph, and endomorph).

The three types of muscle fibers are:

• Type 1 or slow-twitch muscle Fibers

• Type 2A or Moderate Fast Twitch Fibers

• Type 2b or Fast Twitch Fibers

Type 1 or Slow Twitch Fibers

These fibers have a low capacity for generating high force and contract slower than the other two types. This type of fiber is more efficient at using oxygen to generate ATP via aerobic processes. As a result, these fibers can contract for a long time and cannot generate intense force. Activities associated here are long-distance runs, walks, and activities minimum two minutes and longer.

Properties

• Contraction time: Slow

• Size of motor neuron: Small

• Resistance to fatigue: High

• Force/Speed Relation: Low Force/ Low Speed

• The activity used for Aerobic Activities

Type 2A or Fast Twitch Oxidative Fibers

These fibers have a high capacity for generating force but contract very quickly. These are fibers that have the ability to act like Type 1 (slow-twitch) fibers, while also being able to create their own energy like the type 2x(fast-twitch fiber). These fibers are used for activities that last a short duration but must generate a lot of power. Activities range from 400-800 meters sprints to doing repeated lifts with weight moderate weight.

Properties:

• Contraction time: Fast

• Sizeofmotor neuron: Large

• Resistance to fatigue: Intermediate

• Force/Speed Relation: Medium Force, Medium Speed

• The activity used: Long Term Anaerobic

Type 2b or Super Fast Twitch Fibers

These fibers have a very high capacity for generating force and contract quickly. You can associate powerful and strong movement and activities with this. Activities can be doing 100m sprints to submaximal to maximal lifts for 5-8/10 reps.

Properties:

• Contraction time: Very Fast

• Size of motor neuron: Very Large

• Resistance to fatigue: Low

• Force/Speed Relation: High Force, high Speed

• The activity used: Short Term Anaerobic

The Energy Systems

Now that we understand the types of muscle fibers found in the body, let's look at the systems.

There are three energy systems:

• ATP/PCr

• Anaerobic Glycolysis

• Oxidative (Aerobic) System

ATP/PCr Energy System

ATP/PCr Energy System: This system of energy production is used for short, intense bouts of activity lasting from zero to ten seconds. For example, an athlete may sprint 100 meters and deplete their ATP/PCr stores then must rest and allow the muscles to replenish ATP/PCr before another bout of activity to be performed at a high intensity.

These exercises are the fastest and shortest lasting, which makes this a popular choice for athletes that participate in short, explosive events such as playing football or sprinting to catch an incoming pass. Your body will require longer rest intervals during the shortest duration energy system.

You can do resistance training based on velocity-based training (VBT) to improve your efficiency in this system. I great reference in learning more is a book by my mentor Nunzio Signore, owner of rockland peak performance called Velocity-based training.

The components of fitness that fall in this category are:

• Power

• Speed

• Agility

• Max Strength

• Absolute Strength

Main Muscle Fibers Involved:

• Type 2A or Moderate Fast Twitch Fibers

• Type 2b or Fast Twitch Fibers

Anaerobic Glycolysis Energy System

Anaerobic Glycolysis Energy System: This system of energy production is used during long, intense bouts of activity lasting from thirty seconds to 120 seconds of near-maximal intensity. For example, a sprinter running a 400 meter or 800 meters would be working within this system. The person would benefit from training that enhances their capacity for the anaerobic glycolysis process to fuel their muscles during the entire race.

Without this system, they would fatigue quickly and be left exhausted for the remainder of their race despite their best efforts. When you "hit the wall", it would feel like trying to run or move with 1000 lbs of stone holding you back.

The components of fitness that fall in this category are:

• Strength

• Hypertrophy

Main Muscle Fibers Involved:

• Type 1 or slow-twitch Fibers

• Type 2A or Moderate Fast Twitch Fibers

Oxidative (Aerobic) Energy System

The oxidative system is the powerhouse of aerobic energy production. What's happening in the body is that blood with oxygen travels from the lungs to the heart through the veins and arteries to drop off to the muscles while transporting carbon dioxide and other wastes through the blood back to the lungs. You can read more about this in my cardiorespiratory system article.

This system of energy production is used for low- to moderate-intensity bouts of activity lasting anywhere from two minutes down to two hours plus. This is the system used in endurance sports such as distance running, long-distance cycling, and swimming. The body adapts to this training by increasing the volume of mitochondria (the powerhouse of the cell) in the muscles being used. This increase in volume amplifies your cells' ability to produce ATP aerobically without accumulating lactate within the muscles and bloodstream which leads to fatigue.

The components of fitness that fall in this category are:

• Hypertrophy

• Aerobic

• Muscular Endurance

• Flexibility

Main Muscle Fibers Involved:

• Type 1 or slow-twitch Fibers

• Type 2A or Moderate Fast Twitch Fibers

Are the energy systems connected?

Yes, they are. In the image above showing the three energy systems on a graph, you see several points where the energy systems intersect. There are buffers where it takes time for the body to fully kick into anaerobic-glycolysis and the aerobic system. At some parts of your training, you are using 2 to 3 energy systems to produce energy to allow you to complete a task or exercise.

Prioritizing the Energy Systems in Training

When it comes to prioritizing energy system development, several factors come into play. Are you training for an event/sport? Are you training for health reasons? When's the event/sport? Have you been training? Have you plateaued and always fatigued?

First and foremost, complete an assessment to see where your fitness level is, find out your goals, and prioritize the right activities for you to attain your goals through a needs analysis.

With that being said, let's take a deep dive into what encompasses the total potential of energy production.

Energy Production Overview

10,000-foot view

Look at the image above, all three energy systems have a part to play in the total production(capacity) and rate of energy production. Based on your current fitness levels in power, strength (ATP/PCr), hypertrophy, muscular endurance, long-distance (anaerobic glycolysis/ aerobic(oxidative), and the components of energy production and utilization will determine your total fitness.

Vase Analogy

Let's create a visualization to better understand how energy system training would do to improve your energy capacity and why it's beneficial. Imagine we have two vases in front of us. Both vases are the same height. Vase 1 is smaller in diameter and vase 2 is wider. Picture water being filled to the brim in both vases. Now our job here is to fill up as many cups with water from the vase.

Which vase will hold up more? If you said vase 2, you got it. The more capacity you have for production, the more you can produce.

The same principle applies when you are in great overall shape due to energy system training. You are able to go longer, at greater speeds, forces, and reduce the risk of injury. This will allow you to get stronger, move faster, and look great!

Components of conditioning

The name of the game with training is efficiency and efficacy to be able to be stronger, faster, more powerful, last longer in whatever it is that you do for work, fun, and in between.

When it comes to the components of energy system development, there are six. There are two main categories, energy production, and energy utilization. Within that, there are three components in each.

I do want to mention that all the components that we will go over correlate with each energy system. Bulletproofing each energy system to be able to perform optimally and repetitively is the goal here.

Energy Production

• Rate of energy production (Power)

• Duration of energy production (capacity)

• The total potential of energy production (biological power)

Energy Utilization

• Central Governing Control (Power Regulation)

• The efficiency of Energy Expenditure (Skill & Technique)

• Neuromuscular contractility (Mechanical)

Energy Production

Rate of energy production (power)

Going over Energy production, the rate of energy production comes down to how fast you generate energy(ATP) during any of the three energy system processes to creating energy. This will impact how quickly your muscles will contract and relax(stretch-shortening cycle). The more power you can generate for the given energy system and muscles fibers associated with the system

Duration of Energy production (Capacity)

Your capacity comes down to how long you can generate energy for any given amount of time.

To see improvement in your capacity, you need to increase your total potential for energy production(biological power) and the efficiency in how you use your ATP(energy).

Using the vase analogy, this would correlate to the capacity to fill more cups. The more capacity you have, the longer you will last.

Total Potential of Energy Production (Biological Power)

Biological power is a term used for training to increase your ability to produce force and power while being able to do so for longer periods of time with proper training.

The four factors in your biological power are:

• Cardiovascular System

• Metabolic System

• Hormonal System

• Neuromuscular System

How the four systems above affect biological power

Training gains (performance, weight loss, strength training, power, etc), happens when you are refueling and recovering.

When you are training you're using up energy, creating micro-tears into your body, all while affecting your neuromuscular system, metabolic system, and hormonal system.

After your training session, the body will be looking to get back into a stable state (homeostasis). This stable state includes the cell's ability to obtain and use energy, make new cells, exchange materials, and eliminate waste. To get back to homeostasis after a training session, you need to replenish your energy by eating the proper nutrients, drinking water, electrolytes. After getting to homeostasis, there's still the element of building new tissues while having other improvements to the muscles (an increase of muscle cross-sectional area/, increased muscular contraction velocity/etc.)

The improvement of your muscles will depend on what component of fitness you are working on, what energy system that component resides in, and what muscule fibers are predominantly trained.

Having a well-crafted strategy and personalized structured training program with proper exercise intensity, rest interval and more will set you up for success no matter your fitness/sport/ or health goal.

The threshold of your biological power will affect your work capacity. Work capacity has to do with the amount of work that you can do within a given period of time. The greater your ability to do work(exercise/activities) based on the energy demands required for your goal/s, the better your will perform for longer bouts with minimal fatigue and the higher chances to succeed.

Going back to our vase analogy, by improving your biological power, it would be like widening the base of the vase allowing it to hold more water than a slimmer vase the same size.

Energy Utilization

Central governing Control (Power Regulation)

When it comes to the central governing control, there's some research stating that our brain's regulation of energy use is the ultimate cause of fatigue and limiting factor in performance.

The more efficient you are with your training, the less fatigue you will feel. When you are feeling fatigued, this is not an indicator to push harder yet to train smarter and/or rest.

Instead of pushing through the fatigued sensation, taking a day to rest or do an activity geared towards recovery will do a lot more for you.

The efficiency of Energy Expenditure (skill & technique)

Efficiency in technique in your exercises and skills are required in any sport, hobby, or event you perform. This focus on movement and skill efficiency will allow your muscles to use use the minimum amount of energy to attain your goal.

A quick example is comparing my skills in Brazilian jiu-jitsu compared to my skills with karate. Karate is a sport I've participated in for years, earned a brown belt with a black stripe while in Jiu-Jitsu, I have two sessions under my belt(aka beginner).

In karate, I'm precise with my movements and it takes a lot longer for me to fatigue when performing punches and kicks. Conversely, when I perform jiu-jitsu and I am rolling, I'm doing a ton of unnecessary movement to get to a goal of submission because of my lack of knowledge and experience. Over time, I'll be able to conserve energy in BJJ due to my efficiency in technique while practicing tactfully and technically. Mastering technique should be your approach with your workouts and your skill training.

Neuromuscular Contractility (mechanical)

Neuromuscular contractility has to do with the ability to contract or relax a muscle.

Neuromuscular contractility has to do with the ability to contract or relax a muscle. Let's go over a quick explanation of how we go from the thought of contracting a muscle to the actual action of it. This normally happens in an instant.

As you can see in the image above, we have an overview of the neuromuscular contraction process. The thought starts in your brain, travels down the spinal cord and through the nerve of the associated muscles that we are looking to get a response (contraction) from. Within the nerve, there are more neurons in charge of creating an action potential to excite a muscle to contract or relax. It's more complicated than this but no need to make this an exercise physiology course.

Working on muscle contractility will improve how fast your muscles will perform those actions of contracting and expanding.

The goal is time increase how fast your muscles do this based on their muscle fiber type, the energy systems the fibers are associated with while improving the capacity to have increase force for longer periods of time.

Conclusion

The human body is a complex machine that needs to be worked and trained in different ways. Our bodies are designed with multiple energy systems, all of which we use to produce energy; however, our priority should not be on one system over the other as they all play an important part in how we function during daily life and athletic performance.

If you’re interested in learning more about energy system training methods, please be on the lookout for part 2 of this blog post “Energy System Training (Methods, Workouts & Exercises” coming out soon.

We also have a 6-week training program that will give you a fitness program to improve get in the best shape of your life with an onboarding assessment, fitness program, meal plan, and community with accountability calls.