Making weight is the practice of dropping body mass before the official weigh-in so an athlete can compete in a lower category, and surveys consistently show the large majority of combat-sport athletes do it. Reviews of the research, including a widely cited 2012 review by Franchini and colleagues, report that most competitors lose weight rapidly in the final week, largely through dehydration. The performance and health costs of that dehydration are well documented, and no method erases them before competition.
24 News Click publishes information, not medical advice. Weight-cut planning belongs with a sports physician and dietitian, especially where dehydration, heat exposure, or illness is involved.
How common are rapid weight cuts?
Surveys across wrestling, judo, boxing, taekwondo, jiu-jitsu and mixed martial arts consistently find rapid weight loss rates in the range of roughly 60 to 90 percent of competitors, with cuts of several kilograms in the week before competition. Franchini's 2012 review of weight loss in combat sports summarized studies showing typical pre-competition losses around 2 to 5 percent of body weight, and sometimes more, achieved mainly through restricted food and fluid, increased exercise, sauna, and plastic suits.
Athletes typically regain most of the lost weight between weigh-in and competition, which is the point of the practice. The question the research asks is what the cut itself does to the body in the meantime.
What does rapid weight loss do to performance?
The clearest finding concerns dehydration. The American College of Sports Medicine's position stand on exercise and fluid replacement, updated in 2007, concludes that dehydration of more than about 2 percent of body mass degrades aerobic performance, and evidence connects greater losses to impaired cognition, mood, and heat tolerance.
Combat-specific studies back this up. Trials in judoka and wrestlers have found reduced performance in repeated high-intensity efforts, lower grip endurance, and worse mood after rapid cuts, although findings vary with the magnitude and method of the cut. Studies of simulated competition after refeeding show some recovery of performance, but not consistently to baseline, and the studies are small.
What are the health risks beyond performance?
Rapid dehydration thins blood plasma, strains the heart's response to exercise, and concentrates the blood. The most serious documented outcome is death: collegiate wrestling deaths in the United States in 1997, three in about a month among athletes cutting weight with fluid restriction, sauna, and vapor-barrier suits, prompted rule changes by the National Collegiate Athletic Association, including limits on practice weight and body-fat floors.
Organizations including the American College of Sports Medicine have published consensus statements warning against large rapid cuts. The International Olympic Committee's framework on relative energy deficiency in sport adds a chronic dimension: repeated underfueling to stay near a weight limit is linked to hormone disruption, bone-density loss, and impaired immunity.
Do longer, gentler cuts work better?
Gradual loss carries a smaller physiological penalty per kilogram. A 2010 position statement by Artioli and colleagues in combat sports recommended that athletes who intend to lose weight do so gradually, primarily through a modest energy deficit, while preserving lean mass with adequate protein and resistance training, and that they avoid severe dehydration entirely.
For an athlete carrying genuine fat mass, a planned reduction of roughly 0.5 percent of body weight per week, with carbohydrate and fluids maintained, sits within what sports-nutrition guidance supports for preserving training quality. There is no research-based safe method for cutting large amounts of water weight in the final 24 hours; claims of rapid rehydration protocols fully reversing a severe cut are not supported by controlled trials.
What do rule changes and federations do about this?
After the 1997 wrestling deaths, the National Collegiate Athletic Association introduced hydration and body-composition testing at season start, minimum weight certification, and a rule preventing wrestlers from competing below a floor. National and international federations in judo and other sports have adopted weigh-in timing rules, such as same-morning weigh-ins, intended to blunt extreme cuts by shrinking the recovery window.
Evaluation studies of these policies suggest mixed effects: same-day weigh-ins reduce the size of cuts in some settings, while others report athletes simply adapting with smaller, still-dehydrating cuts. The evidence base for policy is thinner than the evidence base for the physiological harm.
What does safer weight management look like in practice?
The pattern supported by the literature is unglamorous: compete near natural weight when possible; make any fat loss gradual during general preparation, not competition week; keep carbohydrate intake and hydration adequate through training; and treat any final-week loss as small and planned. Athletes who compete within a couple of kilograms of training weight avoid the documented performance and health penalties that the dehydration literature describes.
Several fighters at the highest levels have publicly moved up a division after repeated hard cuts, and their teams' decisions match what the physiology research implies: the cut that maximizes size advantage can cost more in performance than it gains. That is an individual strategic choice, best made with medical support.
What does the evidence not show?
The evidence does not show a safe rapid cut of the size many athletes actually perform. It also does not show that any rehydration protocol fully restores performance after significant dehydration; the trials testing recovery drinks, sodium loads, and intravenous fluids after cuts are small and their results inconsistent. Gaps remain because severe dehydration trials in athletes raise obvious ethical limits.
How do early weigh-ins change the picture?
Many professional promotions and some federations hold the official weigh-in the day before competition, with a second same-day safety check. The schedule matters because it sets how much time an athlete has to refeed and rehydrate before fighting. A same-day morning weigh-in leaves hours, and the research suggests this constraint discourages the largest cuts, since there is no realistic overnight recovery.
Day-before weigh-ins have the opposite effect. Studies following mixed martial artists document cuts and regains of up to roughly 10 percent of body mass between weigh-in and fight night. Reviews in combat-sport science note the paradox: rules intended to protect athletes can expand the window for dehydration, which is the argument some sports scientists make for additional limits on how much mass may be regained, policies some national federations have trialed.
Athletes reading this should treat the weigh-in schedule as a fixed constraint of their sport, set by their federation or promotion, and plan any body-weight strategy around it with medical support rather than around folklore from the gym.
FAQ
How much weight can an athlete cut without harming performance?
Dehydration beyond about 2 percent of body mass measurably degrades aerobic performance and repeated-effort capacity, per the American College of Sports Medicine's fluid replacement position stand. Combat-sport trials show performance costs growing with the size of the cut, which argues for cuts of no more than a couple of percent of body weight, achieved without severe dehydration.
Are sauna and plastic-suit cuts still common?
Surveys summarized in Franchini's 2012 review describe these methods as widespread despite bans at some levels, including the NCAA prohibition of vapor-barrier suits after the 1997 wrestling deaths. Prevalence varies by sport, country, and level of competition.
Does rehydrating overnight after the weigh-in restore performance?
Partially at best. Full restoration of body water takes a day or more after significant dehydration, and combat-sport studies show inconsistent recovery of high-intensity performance even after aggressive refeeding and rehydration protocols.
For more context, read Low energy availability: the warning signs athletes should know.
For more context, read what to eat before morning training.
For more context, read hydration plan for athletes.