The Metabolic Demands of MMA

Myths and misconceptions about the science of training can end a fighter’s career before it starts. The main objective of this series of articles is to set the record straight in one area in particular: the metabolic demands of mixed martial arts (MMA). This article will explore how your body powers the repeated high intensity efforts that characterize the sport. When you understand this, not only will you appreciate why you fatigue or gas-out in the cage, but you will know how to bring about specific physiological and biochemical adaptations that will optimize your performance on fight day.

Before we go on, I’d like you to first consider whether or not you hold any misconceptions about the metabolic demands of MMA. I’ve listed a few statements below to test your knowledge. See if you can separate the true statements from the false statements:

True or False: MMA is dominated by the anaerobic energy systems, which support powerful takedowns, grappling and powerful combinations. For this reason I should spend most of my time training the powerful anaerobic energy systems.

True or False: In a typical bout of MMA, aerobic energy systems don’t contribute much to my performance, especially compared to the anaerobic energy systems, so I don’t need to train the aerobic energy systems as much.

True or False: I shouldn’t train the aerobic energy systems very much because it will impair my strength and power development.

Ok, that’s it; how do you think you did? Are you 100 % confident in all of your answers? Here are the results: all of the above statements are false. If you’re not exactly sure why this is so, or if you disagree with me, then this series of articles on the metabolic demands of MMA is for you. We will be covering this topic from a scientific perspective, providing evidence for every claim we make and every myth we bust. This material is not ‘easy’, that’s why there are so many myths and misconceptions on the topic. When reading these articles, you will probably become confused and frustrated at some point. Send me your questions and I will help you as best I can. Remember, if you can master this material, you will have the key to unlocking your full potential in the cage. 

What you will learn

If you’re going to understand how your body powers the repeated high intensity efforts that characterize a typical bout of MMA, you first need to understand how energy is created and transferred in the human body. For this reason, we’re going to review the basics of energy transfer in Part 1 of this article. This will serve as the foundation for everything else we talk about, so don’t skip it! In Part 2 we’ll focus on the energy system that is responsible for powering those short explosive efforts in the cage, like takedown attempts or powerful combinations. In Part 3 you’ll learn about the energy system that supports prolonged efforts, like extended grappling. Part 4 and 5 of this article will examine the energy systems that are responsible for supporting repeated high intensity efforts over a whole round, and over a whole fight.  

If you’re interest in this, you might consider enrolling in our FREE online training program on the Bioenergetics of MMA

You will learn how each energy systems works, I’ll show you how to target each system with exercise by manipulating the work-to-rest ratio, the work interval length and the rest intervals, and I’ll list the physiological and biochemical adaptations that you can expect when you target these energy system.

Mastering this material is critical for your success in MMA. From an educational perspective, knowing this information can help you separate good training advice from bad training advice. You may also save time and money on training plans that don’t work. From a performance perspective, you will improve your ability to perform repeated high intensity efforts over the course of a whole round, and over an entire fight. From a physiological and biochemical point of view, you’ll improve your aerobic and anaerobic fitness while avoiding reductions in strength and power that can follow certain types of aerobic training. Ok, let’s introduce the topic for Part 1: the basics of energy transfer.

Part 1: Energy transfer 

The basics of energy transfer

The energy that powers muscle contract comes from the food we eat. Macronutrients like carbohydrates, fat and protein are broken down into substrates like glucose and glycogen (from carbs), free fatty acids and glycerol (from fat), and amino acids (from protein). These substrates are used to generate energy with oxygen (aerobic metabolism) and without oxygen (anaerobic metabolism). Carbs, fats and protein can all broken down aerobically to produce energy, this reaction also produces carbon dioxide (CO₂) and water. Anaerobic metabolism on the other hand, can only generate energy from carbs, but this chemical reaction produces hydrogen ions (H⁺) in addition to CO₂. This increase in H⁺ is important because it can cause an increase the acidity of your muscle, which may impair muscle contraction and hurt your performance in the cage.

So you might be asking the question ‘why don’t our bodies just rely on aerobic metabolism; that would prevent the build-up of H⁺ right’? Well, aerobic metabolism can’t produce energy very quickly, and when you perform a take-down or a powerful combination, it cannot produce all of the energy that you need. Anaerobic metabolism produces energy much faster than aerobic metabolism. That’s why it’s so important in high intensity-short duration activities like take-down attempts, grappling and short striking combinations. But remember, anaerobic metabolism cannot produce energy for very long and it produces by-products that may impair your performance. Aerobic metabolism is probably more import in longer-duration lower intensity activities, but it is also critical in topping up your energy supply between repeated high intensity efforts. This is why the aerobic energy systems are so important in MMA.

Think of anaerobic energy metabolism as having a high power output and a low capacity. Think of aerobic energy metabolism as having a low power output and a high capacity.

In the human body energy is stored in chemical form, in a molecule called adenosine tri-phosphate (ATP). ATP is made up of one adenosine molecule and three phosphates. Most of the energy is actually stored in the third phosphate bond. When this third bond is broken, energy is released and muscles contract. Importantly, one H+ is released when the third phosphate bond is broken, and both the phosphate and the H+ can build up around the muscle and possibly impair muscle contraction and your performance (3, 4).

After the third phosphate bond has been broken, there are only two phosphates remaining. This leaves one molecule of adenosine di phosphate (ADP). This is a problem because we need ATP for muscle contraction. Of course, ATP is always present in the muscle, but in very low concentrations; approximately 100 grams, or just enough to power a few seconds of normal physiological functioning (1). If our muscles are to continue contracting, ATP must be continuously re-synthesized.

As you have probably guess by now, ATP resynthesis is achieved using aerobic metabolism and anaerobic metabolism. On the anaerobic side, there are two energy systems responsible for generating ATP. One is called the ATP-PCr system and the other is called anaerobic glycolysis. There are also two energy systems responsible for generating ATP aerobically. One is called aerobic glycolysis and the other is called aerobic oxidation. Each of these energy systems are shown below in Fig 2.

In the upcoming sections (Parts 2 through 5), you will learn how each energy systems works, I’ll show you how to target each system with exercise by manipulating the work-to-rest ratio, the work interval length and the rest intervals, and I’ll list the physiological and biochemical adaptations that you can expect when you target these energy system.

Take home message from Part 1

• The energy that powers muscle contract comes from the food we eat. Carbs, fats and proteins are broken down aerobically, but only carbs can be broken down anaerobically. Anaerobic metabolism is a high power, low capacity system that produces energy, CO₂ and H⁺. Aerobic metabolism is a low power, high capacity system that produces energy CO₂ and water.
• The body stores energy in ATP (one adenosine molecule and three phosphates).
• When the third phosphate bond is broken, ATP is converted to ADP. Energy is released, which powers muscle contraction, but a hydrogen ion and phosphate are also released, both of which can build up around the muscle and impair muscle contraction and possibly hurt your performance.
• ATP must be available for muscle contraction to occur, so it must be generated. There are four ways of regenerating ATP
  • The ATP-PCr system (anaerobic energy system)
  • Anaerobic glycolysis (anaerobic energy system)
  • Aerobic glycolysis (aerobic energy system)
  • Aerobic oxidation (aerobic energy system)

Part 1 References

1. Mougios Exercise Biochemistry. Champaign ILL, Human Kinetics (2006)
2. Plowman SA, Smith DL. (2011). Exercise Physiology: For Health, Fitness, And Performance (3^rd ed.). China: Lippincott Williams & Wilkins.
3. Spriet et al., J Appl Physiol 66:8-13 (1989)
4. Westerbalad et al., News Physiol Sci 17:17-21 (2002)