Issue 225

January 2026

Ray Klerck explores why MMA fighters feel sharp right up until their biology pulls the pin.

The mind is the master, and the body is the slave. That’s what we’re all taught. It’s easy to believe, too. You just had to look at Tony Ferguson, especially during his 12-fight win streak, to believe he was titanium forged. The same goes for a peak TJ Dillashaw. They both seemed indestructible, despite having logged more miles than most fighters should ever survive. For long stretches, none of them seemed compromised, but that was the mirage of feeling fine. This physiological illusion might be behind the downfall of MMA’s greatest, if we’re to believe a 2026 paper in Rehabilitation & Recreationthat found feeling fine might be a signal that things are about to change for the worse. For fighters like Ferguson and Dillashaw, this might have played a factor in their decline. The research outlines how elite fighters maintained their speed, power, and technical output despite their internal systems being under extreme strain. For some, the muscle damage markers increased, energy reserves declined, and stress hormones fluctuated, but their performance was still on point. For them, nothing felt wrong or off, but the quiet internal strain can sneak up over time to deliver a surprise attack despite feeling sharp. Think of it as a burnout blind spot that fighters like Junior Dos Santos found out the hard way prior to his fight with Cain Velasquez, where Junior felt like he was in the best shape of his life. He was training hard and feeling amazing, but then gave himself rhabdomyolysis when muscle breaks down so severely that it leaks proteins into the bloodstream, which can damage or shut down the kidneys. The end result was Junior showing up as a ghost of his best self to give Velasquez the Knockout of the Night award. If you’re a fighter, here’s what could be happening on a smaller scale, and you don’t even know it. 

WHEN THE BODY LIES TO YOU

Feeling good in the lead-up to a fight is like being the loudest guy in the restaurant who hasn’t paid his bill yet. There’s plenty of confidence until the waiter shows up with the tab for that fillet steak. That’s what the study uncovered when it followed 80 elite combat athletes through an 8-week MMA preparation block. These were fighters transitioning into MMA who had experience in kickboxing, Muay Thai, Greco-Roman wrestling, and judo. They knew their way around the dojo, but this meant that even the kickboxers and judokas carried high baseline levels of creatine phosphate and muscle glycogen reserves, which are muscle-damage markers that were above the normal ranges, which is something you might expect. The kickboxers had muscle damage markers that were 14.2% higher than normal at rest, before the study’s training load was added. Despite this, they were able to pump out their high-intensity signature strike combinations and throws without drops in output. Across the weeks, as the muscle-damage markers climbed, cortisol, your stress hormone, fell, in some cases by almost 20% in response to explosive high-intensity efforts. This is not what you’re expecting and is a pattern the researchers called “functional overtrain.” It meant their fighters’ adaptation reserves were being depleted rather than being topped up. Think of it like Gordon Ramsay going quiet in the kitchen. When the shouting stops, the food service isn’t smooth, which means the system could be overwhelmed and in panic mode to conserve what’s left. It’s as if the kitchen staff were still plating dishes, but the pantry was empty. For fighters, feeling fine wasn’t the green light. It was the warning sign that the body had stopped arguing back. Internally, it means their creatine phosphate and muscle glycogen reserves were declining, while external performance masked the internal strain. This explains the trap. By the time the fighter actually felt tired, the data said that their training had already been overreaching quietly for weeks. 

AN OPEN WINDOW FOR INFECTION

In light of all the above information, trying to finish a fight camp while cutting weight is like being a bank manager with a staff of sleepy mall cops and a rusty padlock. You might feel locked in, but you’re far from it. The training load burden that MMA training places on the body is often immense because the skill set demands are greater than most other sports. Couple this with the threat of getting hit in the face, and it’s easy to see why fighters probably train harder than they should. To make things even more tricky, a 2026 systematic review in the International Journal of Molecular Sciences looked at MMA fighters as they cut weight before a fight and highlighted a phenomenon they called the “open window.” They found that when fighters cut more than 5% of their bodyweight in the final week before a fight, they weren’t just losing water. Instead, they were handing out skeleton keys to every virus in the building. Cutting triggers a hormonal surge that hangs a do-not-disturb sign on the immune system. Your T-cells stop multiplying, and Natural Killer (NK) cells, which are the frontline soldiers that hunt down viruses, lose a lot of their punching power. While your white blood cells look strong on paper, this new research suggests that they might be functionally broken and lack the ability to kill pathogens. It’s why so many fighters end up with a pre-fight flu or respiratory infection the week of a fight, thanks to a depressed immune system. Robert Whittaker. Brendan Allen. Alex Perieira. Sean Strickland. They’ve all complained of these types of ailments showing up at the worst possible time. It isn’t bad luck. Their weight-cutting protocols combined with a high pre-fight training load can turn their immune system into a ghost town, leaving them vulnerable at the exact moment when they needed to be indestructible.

THE BIOLOGICAL DEBT COLLECTOR

The conclusions from these new bodies of research only serve to confirm what so many fighters and coaches already know because they’ve seen it played out. That said, it is a cold splash of water for the "tough it out" crowd. The only way to avoid the crash is to stop guessing and start measuring. You don’t need to be telling yourself that if you’re not throwing up in a bucket before a fight, then you’re lazy, because the data showed that your biology is a far more sophisticated liar than you are. You’re an expert at lying to yourself and don’t even know it, but that lie often becomes unravelled when the stage is set. We’ve all seen that fighter in the back room shadowboxing like a possessed assassin, only to walk into the cage and look like they’re fighting underwater thirty seconds into the first round. That’s not a lack of heart or pre. That’s when you’ve already spent your emergency energy reserves on a Tuesday morning pad session because you thought "feeling sharp" meant you were recovered. In the modern game, "feeling fine" might be the low-fuel light that you’ve taped over so you don't have to look at it. You can ignore the markers, dismiss the tanking cortisol, and laugh at the high muscle damage levels all the way to the arena. However, the biological debt collector doesn’t care about your championship mindset. The bill always comes due, and it’s paid in consciousness, lost win bonuses, and the sudden, confusing realization that your legs have turned into overcooked linguine exactly when you needed them to be rebar. Don't wait to tell you what a simple blood test could have warned you about weeks ago: stop listening to your gut and start listening to the science. The idea is to pay attention to your recovery, because it’s as big a factor as putting in the hard work.