Conditioning Myths: Busted

When you see a fighter gas it’s usually not because he’s out of shape. Sometimes there’s more going on than meets the eye.

We’ve seen it before, and it’s an awful thing to watch. It’s the middle of a fight, everything’s going well, and before you know it, a fighter “gasses out.” Sometimes he’s saved by the bell, and sometimes he’s even able to defend himself enough to continue and regain his strength. More often than not, however, he’s left defenseless, and his opponent takes advantage and ends the fight.

Clay Guida vs Gray MaynardCountless fighters have lost fights this way—even some of the biggest matches of their careers. And it’s not because their opponents had more skill or better strategy, but because they gassed. From amateurs to top professionals, regardless of the level of competition, gassing out is the great equalizer in combat sports.

Given the obvious importance of making it through an entire fight without gassing—not to mention what’s often at stake for a fighter’s career—we need to know why so many fighters gas out in the first place. This would be understandable, to a degree, if we’re talking solely about amateur athletes, but when world titles change hands because one of the fighters gassed, it’s clear this phenomenon has little relation to skill level or experience. In fact, it’s rare to see an entire card, even at the UFC level, without someone gassing out.

We see these debates online all the time. People want to know why fighters did or didn’t do certain things when they lose, and when it’s because they gas, the near-universal consensus is that it happened because they “weren’t in shape.” After all, when you’re out of shape, you’re bound to gas out sooner or later – and when you’re in shape, it means you can always last bell-to-bell, right?

The casual fan believes the answer to this last question is a resounding “yes,” but the real answer is far more complex than you’ve been led to believe. If you don’t know anything about the sport and you watch a UFC card, it probably doesn’t look much different from a bar brawl. If you’ve tried MMA for even a day, however, you understand and appreciate how incredibly technical and precise the sport is. In this same spirit, gassing out is far more complex than most people realize.

The more you understand about how energy production in combat sports really works, the more obvious it becomes that thinking fighters gas simply because they’re out of shape is akin to believing that getting in a lot of street fights qualifies you for the UFC. If you don’t understand the tremendous skill involved in fighting, this may seem logical, but anyone who has ever set foot in a gym and trained knows it’s just not that simple.

MMA Conditioning Myth Busting

To begin to form an understanding of the bigger picture with regard to conditioning, gassing out, and being in shape for combat sports, we need to start with a clean slate and put an end to many of the common myths surrounding the topic. Despite its importance and the frequency with which gassing out occurs, there are more misconceptions about this aspect of the sport than almost any other.

“He built up too much lactic acid”

Despite the fact that scientists have known that this is not the case for many years, this myth is all-too-frequently cited as the underlying mechanism of what happens when a fighter gasses out—even by otherwise knowledgeable people. The truth, however, is that lactic acid is never the reason fighters gas out. This is because it doesn’t even exist in the human body (Robergs RA, 2004). There is never any lactic acid in your muscles, either during fights or otherwise.

Instead, a substance known as lactate is produced when your body breaks down carbohydrates and turns them into an energy source your muscles can use through a process called anaerobic (without oxygen) glycolysis. Rather than causing fatigue in your muscles, the chemical steps that result in lactic formation actually help prevent fatigue and are an absolutely vital process in energy production. In other words, lactate is your friend, not your foe.

“He ran out of gas”

This is a catch-all term that essentially means a fighter is running low on energy, and it’s another one that seems to make sense on the surface, yet fails to hold up under the microscope of exercise physiology.

The truth is that the chemical fuel on which your muscles and your entire body run, Adenosine Triphosphate (ATP), never drops below 60 percent of resting levels in working muscles, even during the most intense periods of exercise and exertion (Westerblad H, 2010). Fights also don’t last long enough for your muscles to run out of glycogen, the stored sugar used to make ATP.

You don’t fatigue because your muscles run out of energy. It doesn’t happen, because your body is smarter than you. If your car runs out of gas, you just end up getting stuck somewhere. By contrast, if your muscles actually did ever run completely out of ATP, there would be serious cellular damage, and you’d be in major trouble.

To prevent this from happening, the body has a number of failsafe mechanisms in place to make sure your muscles never run as low on ATP as people run their cars on gas. The entire metabolic system is designed to make sure there is always gas left in your tank. It may look like a fighter has no energy left whatsoever when he’s gassing out, but in actuality, his tank is more than half full.

“He Was Just Out Of Shape”

We’ve all heard fighters say they feel like they’re in the best shape of their lives going into fights—or talking about how they’re able to “go forever” in training—only to end up gassing out in the second round. What happens there? Were these guys not in the kind of shape they thought they were in? Are all fighters who gas out in bad shape?

There are two sides to the equation here: energy production and energy expenditure. If you don’t look at both sides, you’re failing to see the whole picture, and this makes it easy to formulate incorrect assumptions. Energy management is really what determines whether a fighter can go bell-to-bell—or ends up gassed out and face-down on the canvas.

Picture two fighters who are both in the same shape. They’re about to fight each other. Fighter A is determined to finish the fight quickly and loves to knock out people, so he swings for the fences with every punch and is constantly pressing forward. Fighter B, by contrast, is highly defensive. He’s patient and carefully picks his shots—always waiting for a mistake to capitalize on before exploding and expending a lot of energy.

It’s not hard to see which fighter is more likely to end up gassing out. Fighter A is constantly expending more energy at a much faster rate than Fighter B, so consequently, he’ll fatigue much more quickly. If he can’t finish the fight early, he’ll likely be significantly slower and gassed out by the end.

This difference in energy management—how and when each fighter chooses to use the energy they’re capable of producing—plays the biggest role in how quickly they fatigue. A fighter can be in great shape, but if he manages his energy poorly, he’ll still end up gassed before a fighter who’s smarter about his pacing and energy expenditure. This is why fighters gas out at all levels of the sport. The top professionals are typically in much better shape than the guys at the bottom, and they’re still producing a great deal more energy. No matter what kind of shape they’re in, however, they can
still gas if they don’t use their energy wisely.

Why MMA Fighters Really Gas Out

To understand exactly why poor energy management can lead to gassing out, you have to examine the basics of energy production. We’ve established that muscles don’t fatigue because of lactic acid buildup, and they’re not running out of energy, so what’s really happening?

Although science can’t fully explain the mechanisms yet, it’s well documented that the greater force and power a muscle produces, the faster it fatigues (Enoka RM, 1992). This is why you can’t run a mile at the same pace you can sprint 100 meters. The more energy your body produces anaerobically (without oxygen), the more power it can generate—but the faster it will fatigue. Higher power activities require ATP to be supplied at a greater rate, so more of it has to come from anaerobic energy production.

Every fighter differs in how much energy they can produce aerobically and how much they can produce anaerobically—and there’s an inverse relationship between the two (Wadley G, 1998). The more energy a fighter can produce aerobically, the better his endurance will be, but the less force and power he’ll be capable of generating. By contrast, fighters capable of the highest power levels also experience the greatest rate of fatigue. This inherent tradeoff between a high work rate (power) and the ability to maintain it, combined with management of energy expenditure, provides the big picture of why fighters really gas out.

Fighters capable of producing a great deal of energy aerobically and managing it effectively will last from bell-to-bell every time. Fighters who can’t produce as much aerobically and have to rely on the anaerobic side—or fighters who don’t know how to pace themselves—are much more likely to gas out every time. The truth here is that energy production and management is as complex and variable as the fight-specific skills that are being fueled. To the educated eye, gassing out is not a simple issue at all, but yet another piece of a complex puzzle that ultimately determines whose hand is raised and who is left lying on the canvas.

Enoka RM, S. D. (1992). Neurobiology of Muscle Fatigue. Journal of Applied Physiology , 72:1631-1648.
Robergs RA, G. F. (2004). Biochemistry of exercise induced metabolic acidosis. Am J Physiol Regul Integr Comp Physiol , 287: R502–R516.
Wadley G, L. R. (1998). The relationship between repeated sprint ability and the aerobic and anerobic energy systems. Journal of Science Med Sport , 1:100-110.
Westerblad H, B. J. (2010). Skeletal Muscle: Energy Metabolism, Fiber Types, Fatigue and Adaptability. Experimental Cell Research , 3093-3099.


With so much emphasis in recent years being placed on the development of explosive power, endurance training or “road work” has lost some of it’s luster. But while endurance training for the average athlete may not produce results as quickly as intervals, at the elite level, the small percentages in return can be the difference between lifting UFC gold or becoming a name that could have been.

Building your aerobic capacity to augment your explosive anaerobic capabilities is important for several reasons. A larger aerobic base means your anaerobic engine is used less often, sparing it for more critical moments in the fight. And because ATP is a byproduct of aerobic respiration, a large aerobic base means your anaerobic engine has more fuel at it’s disposal. These increases in efficiency also mean faster recovery times between rounds and faster recovery after workouts.

For centuries, warriors of all cultures have relied on running and endurance training as a fundamental component of a well balanced training program. As the sport of MMA evolves, even fighters with the most elite level of a particular skill, have to develop a balanced game in order to succeed. The same is true for conditioning. Make time for your road work and you will be one step closer to reaching your full potential as a fighter.


A resting heart rate as low as Michael Bisping’s phenomenal 34bpm, doesn’t come easy. Only a highly effi cient aerobic system with a high red blood cell count, and cells bursting with energy producing mitochondria can cruise along at such a slow rhythm. FIGHT! Recommends using MRI’s newest product EO2 VMAX in conjunction with your regular conditioning to help boost your aerobic base and overall fitness. Available now at

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