The Risk and Reward of Weight Cutting

Weight cutting has become an accepted, almost expected part of combat sports like boxing and MMA. For decades, fighters have manipulated their bodies to make a specific weight class, only to step into the ring or cage a day later significantly heavier and (ideally) stronger. But while this practice can offer advantages, it also carries serious risks — both short- and long-term.

At its core, weight cutting is the process of losing body mass quickly, usually within days before a weigh-in. This is typically done through dehydration, calorie restriction, sauna sessions, water loading, and other methods designed to shed water weight temporarily. Once the athlete weighs in, they immediately begin “recovery” — rehydrating, eating, and trying to restore energy levels before the actual fight.

The simple answer to why fighters cut weight: to gain a size and strength advantage. A fighter who competes at, say, 70kg might walk around at 78kg during training. By cutting down to 70kg for the weigh-in and rehydrating back to near their original weight, they often find themselves larger and stronger than opponents who walk around closer to the division limit.

In theory, this edge matters — especially in sports where power, leverage, and physical dominance can swing the outcome. It can also be strategic. Fighters might drop a weight class to face smaller opponents or find better matchups.

But weight cutting is far from an exact science, and the consequences can be dangerous.

Severe dehydration impacts everything: muscle function, reaction time, mental clarity, and even heart health. In extreme cases, it can lead to kidney failure, heatstroke, and hospitalization. Fighters often report headaches, dizziness, and a loss of coordination during harsh cuts — symptoms you wouldn’t want right before a high-stakes fight.

In MMA, where grappling and clinch work are intense, a poorly done weight cut can destroy a fighter’s stamina and durability. In boxing, it affects punch resistance and timing. Many fighters don’t bounce back fully after the cut, and that lag shows in their performance.

Beyond the fight itself, chronic weight cutting can harm long-term health. Hormonal imbalances, slowed metabolism, and psychological stress are all common in athletes who’ve cut weight aggressively for years. Some athletes never fully recover, both mentally and physically.

Combat sports organizations have started to acknowledge these dangers. ONE Championship, for instance, banned extreme weight cutting and introduced hydration tests to ensure athletes compete closer to their natural weight. The idea was to prioritize safety and eliminate drastic last-minute weight cuts.

However, even with hydration tests, a few fighters have found ways to manipulate the system. Timing water intake, manipulating sodium levels, or selectively rehydrating just enough to pass the test are known methods. While these are not widespread practices, they show how challenging it is to fully eliminate the culture of weight cutting — even with rule changes in place.

Even at the amateur and grassroots level, conversations are shifting. Coaches are increasingly cautious about letting young fighters cut too much weight, and some regions have instituted stricter rules about weigh-in times and allowable cuts.

For some, the answer is still yes — if done carefully, under supervision, and with proper recovery protocols. But more and more fighters are choosing to compete at or near their walk-around weight, prioritizing health, performance, and career longevity over a perceived size advantage.

The key is understanding your own body and working with professionals: nutritionists, strength coaches, and experienced trainers who know how to manage weight safely. The days of cutting weight alone in a sauna with a garbage bag and a towel are (hopefully) becoming a thing of the past.

Weight cutting is one of the most complex traditions in combat sports. It can give fighters an edge, but it can also take everything away — including health, performance, and years off a career. As the sport evolves, so should our approach. Because the ultimate goal isn’t just making weight — it’s winning, performing well, and walking away whole.