How long does water weight take to come back?

The answer, in numbers, before the reasoning

If the question is body mass, the published range runs from about three hours to about thirty.

Barley and colleagues dehydrated 14 highly trained male combat-sport athletes (age 25 ± 4 years, body mass 80 ± 11 kg) by 3.2 ± 1.1% using three hours of passive heat at 39.9 ± 0.3 °C and 63 ± 2% relative humidity in a plastic suit, with no fluid intake. Body mass had recovered by the three-hour point after the intervention. At the other end, a prospective interventional study of 31 professional MMA athletes in Rio de Janeiro — 28 men and 3 women, age 28 ± 4 years — recorded a mean regain of 7.5 kg, SD 1.7, equivalent to an 11.25% increase from weigh-in body mass, within 30 hours of the official weigh-in, after a mean reduction of 7.25 kg — 10.56% of their initial body weight — in the seven days leading up to it. Note that the two percentages have different denominators: the loss is against pre-cut mass, the regain against the lower weigh-in mass.

Those are the two ends, and they are not in tension. The laboratory study took off 3.2% and put it back under supervision with the subject sitting still. The field study took off more than three times as much and put it back around eating, sleeping, travel and a fight. More mass takes longer, and the constraint on the return is not thirst.

If the question is hydration status, the answer is that the scale will be right before the urine is. If the question is performance, the honest answer is that it depends entirely on which performance you mean, and the literature does not agree with itself. All three are below.

One thing this article will not give you is a universal number of hours. That refusal is not caution for its own sake. The 2026 systematic review that pooled this literature found a median recovery fraction of 106.5% with a range from 63.2% to 154.1%, and near-total statistical heterogeneity on its two headline pooled estimates. When the spread is that wide, a central number is a fiction with a decimal point on it.

How fast fluid leaves, under conditions that were actually measured

The outbound direction is the easy half, and it is the half people overestimate the difficulty of.

Three hours of passive heat at about 40 °C with no exercise and no fluid produced a 3.2% loss in the Barley cohort. On an 80 kg athlete that is roughly 2.6 kg in three hours, which works out at about 0.85 litres an hour with the subject doing nothing but sitting in a suit in a hot room. Add exercise and the figure climbs. Reported whole-body sweat rates in athletes cluster around 0.5 to 2.0 litres an hour, with a documented range from under 0.5 to over 2.5; the most widely circulated summary of those ranges comes from a sports-drink manufacturer's science institute, so treat the framing as a vendor's even though the range itself is uncontroversial and appears throughout the literature. Those figures are exercising athletes in defined environments, not fighters in a sauna, and they should not be transplanted across.

The rate is not the interesting part. What the rate obscures is that the fluid does not come out of one compartment evenly. An early biopsy study by Costill and colleagues took eight men to successive deficits of 2.2%, 4.1% and 5.8% of body mass by exercising them at 39.5 °C, sampling blood, urine and muscle at each level, and reported that plasma water fell roughly 2.4% and muscle water roughly 1.2% for every 1% of body mass lost. The full text is paywalled and the sample is eight men in 1976, so hold the exact coefficients loosely. The direction is the point and it is not controversial: plasma is drawn down about twice as fast, per unit of body mass, as muscle water.

That asymmetry is the mechanical reason the scale cannot tell you what you did. A scale weighs every compartment identically. A kilogram of plasma volume and a kilogram of gut content and a kilogram of intracellular water are the same kilogram to a set of bathroom scales, and they are emphatically not the same kilogram to a fighter. The blood compartment degrades first and has to be refilled first, and the number on the display is blind to all of it. Even a well-read bodyweight trend cannot separate compartments; it can only tell you the sum moved.

There is one component of pre-weigh-in mass that deserves mention and no number: gut content. It is real, it is reduced by low-residue eating in the final days rather than by sweating, and it returns with the first meal rather than with fluid. We could not locate a primary quantification of gut-content mass in combat athletes, so this article prints no kilogram figure for it, and you should be sceptical of any page that does.

How fast it comes back, and why drinking harder does not help

The inbound direction has a ceiling that the outbound direction does not, and the ceiling is anatomical.

The stomach is not the bottleneck. Initial gastric emptying of clear liquid in the fasted state runs somewhere in the region of 10 to 40 mL per minute — roughly 600 to 2,400 mL an hour — with a half-emptying time for plain water of about sixteen minutes. Adding salt, sugar or any caloric load slows it, and hypertonic or milk-based drinks slow it substantially. These are clinical measurements at summary level rather than numbers we fetched from primary perfusion studies, so read them as an order of magnitude.

The intestine is the bottleneck. Segmental perfusion studies in men at rest put water absorption in the duodenojejunum at a plateau of roughly 11.3 to 12.9 mL per hour per centimetre of intestine with a 6% glucose-electrolyte solution, and — this is the load-bearing finding — that plateau could not be raised by delivering more fluid or more glucose. Across 2%, 4% and 6% carbohydrate solutions the range was about 9 to 15 mL per hour per centimetre. A hypotonic solution at 186 mOsm/kg absorbed around 17% faster than a hypertonic one at 403 mOsm/kg. Small samples, men at rest, abstract-level: hold the decimals loosely and the shape firmly.

The gut is a fixed-bore pipe. Past a certain rate, drinking faster does not absorb faster; it parks fluid in the lumen, where it sits outside the circulation doing nothing for plasma volume — and where it still weighs exactly what it weighed going in. That is the cleanest mechanical explanation available for why mass returns before the athlete does, and it is also the honest answer to "can I just chug it." You can. The scale will reward you for it. Your blood volume will not.

This is the point at which the reader's next question becomes what to drink and in what form, and this article deliberately stops. Composition, sodium, timing and the limits on all three are covered in the rehydration article, which also explains why it refuses to print a protocol.

The dissociation: mass back is not the athlete back

This is the part of the evidence that competing pages on this query consistently miss, and it comes from a single study measuring one cohort at one timepoint, which is what makes it quotable.

Fourteen highly trained male combat-sport athletes were dehydrated by 3.2 ± 1.1% and tested three hours later. At that three-hour timepoint, simultaneously:

• Body mass had recovered.
• Serum osmolality showed no statistical difference from control.
• Haematocrit was not different from control.
• Urine osmolality was 728 ± 326 mOsm against 379 ± 192 mOsm in control, P < 0.001.
• Urine specific gravity was 1.022 ± 0.01 against 1.010 ± 0.005, P < 0.001.
• The athletes completed 17 ± 7 contractions at 85% of maximal voluntary contraction where the control condition completed 23 ± 8 — about a quarter fewer, P < 0.001, Hedges' g = 0.775.
• Perceived fatigue was 11 ± 5 against 6 ± 2, P = 0.012.
• No between-condition differences were observed in central or peripheral indicators of neuromuscular function at any timepoint.

Read that list again with the first line in mind. Everything after "body mass had recovered" happened at full body weight. An athlete in this condition steps on a scale, sees their normal number, and is a quarter short on sustained contractions with no way to know it.

Note what we are not doing: we are not converting 17 versus 23 into a tidy percentage and putting it in a headline. The subtraction gives about 26%, and a derived percentage on a body-facing figure invites exactly the drift this article exists to correct. The measurement is 17 ± 7 against 23 ± 8, and the standard deviations are part of the measurement.

The serum-versus-urine split is not a contradiction, and the mechanism is worth stating plainly: the body defends the blood compartment first and keeps conserving at the kidney. Normal serum osmolality with concentrated urine is exactly what a body that has been given fluid and is still in deficit looks like. Serum normalising is not evidence of repletion; it is evidence that the regulatory system is working.

The meta-analytic version arrives at the same place from 40 studies. A 2026 systematic review of rehydration and nutritional recovery after rapid weight loss in combat sports found that body-mass regain did not consistently correspond to restoration of hydration status, and concluded, in its own sentence, that "body-mass regain should not be interpreted as complete rehydration or restored performance readiness." Its pooled weigh-in urine specific gravity was 1.029 (95% CI 1.025–1.033) across three studies and 58 athletes — well inside the range most thresholds classify as significantly dehydrated. In the single study reporting a 24-hour post-recovery value, USG was still 1.017. What commissions and federations do with numbers like those is a separate question entirely.

What stays abnormal after the scale is right

Laid out as a sequence, with the evidence behind each line:

Body mass. Back by three hours in the laboratory at a 3.2% loss; back within 30 hours in a field cohort at a much larger one. Fastest clock, least informative.

Serum osmolality and haematocrit. Back by three hours in the same cohort. The blood compartment looked normal at the moment everything else did not.

Urine osmolality and specific gravity. Not back at three hours, by a wide margin. In the one study in the 2026 review reporting a 24-hour value, still above the 1.020 threshold commonly used to mark euhydration.

Muscular strength-endurance. Not back at three hours: 17 ± 7 contractions against 23 ± 8, g = 0.775.

Repeat-effort ability. A companion study of 14 MMA athletes tested sled push, medicine-ball chest throw and vertical jump at 3 and 24 hours after a 5% dehydration induced by three hours of cycling at 60 W in 40 °C, with ad libitum food and fluid afterwards, and reported repeat-effort performance still reduced at 24 hours. That paper is behind a paywall; we have its design and its direction from the citation and from open descriptions, and we are not printing an effect size we have not read.

Central and peripheral neuromuscular function. Never impaired in the first place. Whatever failed earlier on the sustained contractions, it was not contractile failure and it was not drive.

Muscle glycogen. Its own clock, roughly 24 hours, and the next section.

Gut comfort. No primary measurement located. Every fighter has an opinion; the literature has nothing we could cite.

Glycogen has its own clock, and the famous ratio does not survive checking

Glycogen is the other half of what people mean by water weight, and it runs on a schedule that is genuinely well characterised. With adequate carbohydrate intake in the region of 1 to 1.2 g/kg/h, a systematic review and meta-analysis of hydration, hyperthermia, glycogen and recovery reports roughly 40% of glycogen restored in the first hour, roughly 75% within four to five hours, and full restoration in approximately 24 hours. That review pooled 18 studies, meta-analysed 13, and covered 158 subjects with a mean age of 23.5 years — small, young and mostly male. A separate review puts complete resynthesis after prolonged moderate-intensity exercise at around 24 hours provided roughly 500–700 g of carbohydrate is ingested.

That 24-hour figure is the structural fact of this whole article. A day-before weigh-in just barely accommodates it. A same-day weigh-in does not accommodate it at all, and no amount of intent changes that.

Now the ratio. "Every gram of glycogen holds three grams of water" is the single most repeated number in weight-cutting folklore, and it is worth following to its source, because the trail ends somewhere unexpected.

The human study everyone means is Olsson and Saltin, 1970: 19 young healthy males, prolonged heavy arm and leg exercise, three days of a protein-and-fat diet, then four days of carbohydrate enrichment, with measurements on day 3 and day 7. Thigh and arm muscle glycogen rose from 4.5 and 2.6 g/kg wet muscle to 19.9 and 16.9. Body weight rose 2.4 kg and total body water rose 2.2 L. Total glycogen stored was calculated to be at least 500 g, from which the authors concluded that 3–4 g of water is bound with each gram of glycogen.

Read that again. The number is a division sum — total body water change divided by an estimate of glycogen stored. Nobody weighed water attached to glycogen. The publisher page returned a 403 on the day we checked; the content is corroborated by two open reviews we did fetch.

Then the measurement that breaks it. Fernández-Elías and colleagues dehydrated nine aerobically trained subjects by 4.6 ± 0.2% with 150 minutes of cycling at 65% of VO₂max in hot-dry conditions, then an hour later gave them 250 g of carbohydrate in either 400 mL of water or the same syrup plus fluid matching their losses (3,170 ± 190 mL), with muscle biopsies. The low-fluid arm produced a ratio of about 1 g of glycogen to 3 g of water. The full-fluid arm produced about 1 to 17. Same carbohydrate, same protocol, same muscle — and the ratio moved by nearly sixfold on the basis of how much the subjects drank. A modern attempt using carbon-13 magnetic resonance spectroscopy with deuterium dilution in eight males estimated a ratio of 1 to 4 or lower after carbohydrate loading, with most of the increase in intracellular water. The animal literature does not converge either: rat and cat studies from the 1930s and 1940s support ratios between 1:1.63 and 1:3.8, while rabbit-liver, rabbit-muscle and rat-muscle studies found nothing.

A 2023 narrative review reaches the conclusion the trail implies: the relationship between body water and stored glycogen is inconclusive, because glycogen-bound water has never been directly measured and because fluid intake and metabolite changes confound every human estimate.

So: 3:1 is a rule of thumb with a known failure mode, and the failure mode is that it is mostly a property of how much you drank rather than a property of glycogen. It is not a constant, it was never measured, and it should not be used as a load-bearing step in planning a cut.

What fighters actually regain, and in what cohort

The pooled figure first, because it has the most athletes behind it. Across 11 studies covering 1,504 combat-sport athletes, mean regain between weigh-in and competition was 6.23% of body mass (95% CI 3.74–8.71); across 12 studies covering 1,451 athletes, 3.71 kg (95% CI 2.45–4.96). The review reports I² = 99.2% on the first and 98.9% on the second — near-total heterogeneity. These are descriptions of a very scattered literature rather than reliable central values, and the review's authors would say so.

The recovery fraction is the more interesting statistic and the more frequently misreported. In the five cohorts where the same athletes' losses and regains could be matched — 179 athletes in total — the median athlete returned at 106.5% of what they had taken off, with a range from 63.2% to 154.1%. That median rests on those five matched cohorts. It does not rest on 40 studies and it does not rest on 1,504 athletes, and you will see it attached to both. The figure with roughly 1,500 athletes behind it is the 6.23%; the figure with the striking ratio is the 106.5%, and they are not two versions of the same number.

The high-end professional case is the Brazilian MMA cohort: 31 professional athletes on a supervised, structured weight-management protocol regained a mean 7.5 kg, SD 1.7 — 11.25% of weigh-in mass — within 30 hours of the official weigh-in, having lost 7.25 kg — 10.56% of initial body weight — in the seven days before it. It was a prospective interventional study with no control group, by the authors' own admission, and the weight-loss methods were not directly monitored. That study also reports that 21 of 31 athletes (67.7%) won their bouts and a positive correlation between regain and competitive success. Do not read that as advice. A single-arm cohort of 31 athletes with no control group cannot support the claim that regaining more weight helps you win, and the authors do not make it.

Saying "fighters regain 7.5 kg" as a general statement would be wrong. Thirty-one Brazilian professionals on a supervised protocol regained 7.5 kg. The literature as a whole says 6.23%, with a confidence interval nearly twice as wide as it is narrow and heterogeneity at the ceiling.

And one correction worth making loudly, because it circulates as a safety framework and is not one. The figures 6.7% of body mass at 72 hours out, 5.7% at 48 and 4.4% at 24 began life as a measurement. They are the average cumulative losses recorded in 616 professional UFC athletes weighed at those three points before the official weigh-in, which the 2025 ISSN position stand later restates as suitable losses. They describe what professional fighters under a promotion's performance staff already do. Nobody established them as safe, and no study in this literature has tested a threshold against harm. They are cumulative rather than stages — the 72-hour figure already contains the 24-hour one, which is why they descend — so they must never be added together. If you have seen a page sum them into a 17% allowance, that page invented a number.

Weigh-in format sets the answer before physiology gets a vote

The single largest determinant of how long water weight takes to come back is not in any of the physiology above. It is a line in a bout agreement.

IBJJF: zero hours. The IBJJF Rules Book, version 6.1, June 2024, has the ring coordinator weigh athletes "before first match," specifies at §8.3.1 that "each athlete shall only mount the official scale of the event to have his/her weight taken once," and at §8.3.3 that the athlete cannot step on the scale with anything besides their regular uniform — the gi. §8.1.13 forbids changing gis between weigh-in and first match under penalty of disqualification. There is no rehydration window because there is no window. Consistent with that, UK Brazilian jiu-jitsu competitors reported mean pre-competition body-mass loss of 1.9 ± 3.8 kg, 2.3 ± 4.6% — roughly a third of what day-before-weigh-in sports report — and the authors noted the methods tend toward calorie deficit via exercise and diet rather than hypohydration. That is abstract-level and the standard deviations are larger than the means, so hold the figure loosely; the direction is the point, and it shapes weight cutting for BJJ tournaments entirely.

Professional MMA in the United States: a documented absence. The Association of Boxing Commissions and Combative Sports' Unified Rules of Mixed Martial Arts, amended with nonsubstantial changes on 6 August 2025, set the weight classes and the catch-weight allowances and stop there. They contain no rule about when a weigh-in happens and no hydration test of any kind. Weigh-in timing is set by the individual athletic commission and the bout agreement, not by the sport's unified rulebook. This is worth stating flatly because the opposite is asserted constantly: there is no "Unified Rules 24-hour weigh-in requirement."

Professional boxing. The ABC's regulatory guidance to commissions suggests a weigh-in no more than 24 and no less than 12 hours before the event, with exceptions at the host commission's discretion. We did not fetch that from the primary document, and guidance of this kind binds nobody until a commission adopts it. Treat it as a description of common practice.

UFC practice. Official weigh-ins are typically held on the morning of the day before the bout, with the exact window set by the presiding commission. That is practice, not rule, and it is the reason the literature's 24-to-36-hour recovery windows exist at all.

The practical consequence is a three-row table:

If you are choosing a division, the recovery window belongs in that decision alongside the size of the cut — which is the argument made at length in how much weight can you cut before a fight.

A worked scenario

This is arithmetic on published figures, not a case we observed. Fighter Cut has no coached roster and no outcomes to report.

Take a 70 kg athlete with a Friday-morning weigh-in and a Saturday-evening bout — call it 32 hours, which is at the upper end of what a day-before format tends to give. Suppose 5 kg comes off in the last week, which is 7.1% of their pre-cut mass and in the neighbourhood of what the literature's matched cohorts report for pre-weigh-in loss.

Apply the pooled regain figure to weigh-in mass: 6.23% of 65 kg is about 4.05 kg, and the pooled absolute estimate of 3.71 kg lands nearby. Apply the recovery fraction instead and you get the honest version of the same calculation: at the median 106.5%, they arrive at about 5.3 kg regained, slightly heavier than they started. At the bottom of the observed range, 63.2% of 5 kg is 3.2 kg, and they walk to the cage 1.8 kg lighter than their pre-cut weight. At the top, 154.1% is 7.7 kg, and they arrive 2.7 kg heavier. Both of those are real athletes in the same pooled literature.

That spread — 3.2 kg to 7.7 kg of regain from an identical 5 kg loss — is why this article will not print a single number of hours. Two athletes with the same body mass, the same cut and the same window can end up four and a half kilograms apart, and the published evidence does not currently explain which one you will be.

Now the part the arithmetic cannot show. At 32 hours the glycogen clock has had time to run, if the carbohydrate was there. Body mass has almost certainly returned; that clock is the fast one. What the measurements say about the other two clocks at that point is thinner than anyone would like: the only 24-hour urine specific gravity value in the 2026 review was still 1.017, and the only 24-hour repeat-effort measurement we could find showed performance still reduced. Two single studies. That is the state of the evidence at the exact timepoint most professional fighters compete at.

Does performance come back with the mass?

The evidence conflicts, and the right thing to do is present the conflict rather than resolve it.

The case that it does. A meta-analysis of Olympic-style combat athletes found that rapid weight loss of up to 5% of body mass in under seven days did not influence strength and power outcomes: standardised mean difference 0.36 (95% CI −0.25 to 0.97), not significant, with intermittent sprint at 0.17 (95% CI −0.20 to 0.54), also not significant. Ten studies met its quality threshold, across judo, wrestling, taekwondo and boxing, predominantly male. The review notes that within three to four hours athletes could recover anaerobic performance toward pre-weight-loss values. Note the ceiling on that conclusion: 5% or less, under seven days, Olympic-style athletes. It says nothing about an 8% cut. Separately, a small judo study — 7 weight-cyclers and 7 controls — found that 5% rapid weight loss followed by a four-hour recovery did not affect judo-specific performance in experienced cyclers, and its authors explicitly warned against extrapolating that to inexperienced ones.

The case that it does not. Seventeen contractions against twenty-three at full body mass, three hours in. Repeat-effort performance still reduced at 24 hours in the companion study. And the 2026 systematic review could not pool a single performance outcome from 23 records across 12 studies; its study-level tally was three showing recovery or improvement, six mixed or unclear, and three showing impairment.

These two bodies of evidence are not actually contradicting each other. They measure different things. Single-effort strength and power come back fast — within hours. What lags is repeated-effort capacity and the subjective cost of producing the effort. The judo athletes did a five-minute combat and three Wingate bouts and were fine. Barley's athletes could produce identical peak torque and identical neuromuscular activation and still failed about a quarter sooner on a sustained contraction, while rating their fatigue at that same three-hour point 11 ± 5 against the control condition's 6 ± 2 (P = 0.012).

A three-round fight is made of repeated efforts and subjective cost. That is the half of the evidence that lags, and it is the half a scale is blind to. If you want a marker that tracks the lagging half, it is not body mass — the argument for what to watch instead is in what to track in fight camp, and it is the kind of multi-signal picture a log is better at holding than memory is.

Who this evidence does not cover

Every cohort behind every number above skews the same way, and it needs saying in the body of the article rather than in a footnote.

The field cohort was 28 men and 3 women, all Brazilian professionals. Both Barley studies were 14 males. Costill's biopsy study was 8 men. Olsson and Saltin's was 19 young healthy males. Fernández-Elías's was 9 trained subjects; Shiose's 8 males; the judo study 14 total. The Olympic-combat meta-analysis describes its pool as predominantly male. The glycogen-recovery review pooled 158 subjects with a mean age of 23.5. The gastric and intestinal work was done in small numbers of men at rest.

Sex differences in sweat rate, in total body water as a fraction of body mass, and in plasma volume are established, and none of them are accounted for here. They are also not the sort of thing you adjust for with a coefficient. Nothing in this article has been validated in adolescents, and adolescent weight cutting carries a separate and better-documented set of harms that is outside this article's scope.

If you are a woman, a junior, or an amateur competing without medical supervision, the correct reading of everything above is that it describes adult male professionals under observation and may or may not describe you.

What we could not verify

• The 24-hour repeat-effort study's effect sizes. The publisher returned a paywall. We have the design and the direction of the finding from the citation and from open descriptions, and we print no sled-push or vertical-jump effect size for it.
• Olsson and Saltin 1970 and Fernández-Elías 2015 in the original. Both were blocked — a 403 and a paywall respectively. Their figures here are corroborated by two open reviews we did fetch, and they are hedged accordingly.
• Costill 1976 beyond the abstract. The plasma and muscle water coefficients are abstract-level. The full text is paywalled.
• Gastric emptying and intestinal absorption at primary level. These come from clinical summaries and abstracts, not from perfusion papers we read end to end. The plateau and its insensitivity to volume are consistent across the sources we saw; the decimals are not something we would defend.
• A gut-content mass figure for combat athletes. No primary quantification located, in any population. Widely asserted in coaching content and, as far as we can tell, never measured.
• The weigh-in-to-competition interval in the 31-athlete Brazilian cohort. The paper is internally inconsistent on it: it states the official weigh-in was "conducted 8 days before competition" and also reports recovery "within the subsequent 30-h recovery period" and its assessments across a 24–36 hour window. Only a day-before weigh-in is consistent with a 30-hour recovery, so this article prints the 30-hour window and no weigh-in-to-bout interval at all. Resolving the contradiction needs a human reading of that paper's Methods.
• The exact publication date of the 2026 systematic review. The article record is consistent with mid-September 2026; we could not put a second independent source on the specific day, so it is cited as September 2026.
• The ABC boxing weigh-in guidance, at primary level. We did not fetch the source PDF. It is described above as guidance rather than as a rule for that reason.
• A comparison of rapid-weight-loss practice under sub-24-hour versus 24-hour-plus weigh-ins. The most directly on-topic paper for the format question returned a 403 on the day we checked. No figures from it appear here.
• Any figure described as a safe unsupervised rate, in either direction. No such figure exists in this literature to cite. Every laboratory number above was produced under supervision with monitoring.

Sources

Sourced to

1. Acute dehydration impairs endurance without modulating neuromuscular function — Barley OR, Chapman DW, Blazevich AJ, Abbiss CR, Frontiers in Physiology, 2018;9:1562, doi:10.3389/fphys.2018.01562
2. Effects of rehydration and nutritional recovery strategies after rapid weight loss on body mass recovery, hydration status, and performance in combat sports athletes: a systematic review and meta-analysis — Sun J, Song H, Sun J, Frontiers in Nutrition, September 2026;13:1943678, doi:10.3389/fnut.2026.1943678
3. An alternative structured weight management protocol to rapid weight loss in mixed martial arts — Maurício CA et al., Frontiers in Nutrition, 2025;12:1581698, doi:10.3389/fnut.2025.1581698, PMCID PMC12540128
4. Rapid weight loss of up to five percent of body mass in less than 7 days does not affect physical performance in official Olympic combat athletes with weight classes — Mauricio CDA, Merino P, Merlo R et al., Frontiers in Physiology, 2022;13:830229, PMID 35492609
5. Repeat effort performance is reduced 24 hours after acute dehydration in mixed martial arts athletes — Barley OR, Iredale F, Chapman DW, Hopper A, Abbiss CR, Journal of Strength and Conditioning Research, 2018;32(9):2555–2561, PMID 28930879
6. Hydration, hyperthermia, glycogen, and recovery: crucial factors in exercise performance — a systematic review and meta-analysis — López-Torres O, Rodríguez-Longobardo C, Escribano-Tabernero R, Fernández-Elías VE, Nutrients, 2023;15(20):4442, PMID 37892517
7. Muscle glycogen assessment and relationship with body hydration status: a narrative review — Shiose K, Takahashi H, Yamada Y, Nutrients, 2023;15(1):155, doi:10.3390/nu15010155, PMID 36615811
8. Variation in total body water with muscle glycogen changes in man — Olsson KE, Saltin B, Acta Physiologica Scandinavica, 1970;80(1):11–18, PMID 5475323
9. Relationship between muscle water and glycogen recovery after prolonged exercise in the heat in humans — Fernández-Elías VE, Ortega JF, Nelson RK, Mora-Rodriguez R, European Journal of Applied Physiology, 2015;115:1919–1926, PMID 25911631
10. Muscle water and electrolytes following varied levels of dehydration in man — Costill DL, Cote R, Fink W, Journal of Applied Physiology, 1976;40(1):6–11, PMID 1248983
11. Upper limit for intestinal absorption of a dilute glucose solution in men at rest — Duchman SM et al., Medicine and Science in Sports and Exercise, 1997, PMID 9107630
12. Segmental extracellular and intracellular water distribution and muscle glycogen after 72-h carbohydrate loading using spectroscopic techniques — Shiose K et al., Journal of Applied Physiology, 2016, doi:10.1152/japplphysiol.00126.2016, PMID 27231310
13. Rapid weight loss followed by recovery time does not affect judo-related performance — Artioli GG et al., Journal of Sports Sciences, 2010;28(1):21–32, PMID 20035492
14. Pre-competition body mass loss characteristics of Brazilian jiu-jitsu competitors in the United Kingdom — White T, Kirk C, Annals of Human Biology, 2021, doi:10.1177/0260106020983800, PMID 33402045
15. Weight loss and competition weight in Ultimate Fighting Championship (UFC) athletes — Peacock CA, French D, Sanders GJ, Ricci A, Stull C, Antonio J, Journal of Functional Morphology and Kinesiology, 2022;7(4):115, PMID 36547661
16. International society of sports nutrition position stand: nutrition and weight cut strategies for mixed martial arts and other combat sports — Ricci AA, Evans C, Stull C et al., Journal of the International Society of Sports Nutrition, 2025;22(1):2467909, PMID 40059405
17. Unified Rules of Mixed Martial Arts — Association of Boxing Commissions and Combative Sports, amended with nonsubstantial changes 6 August 2025
18. IBJJF Rules Book, version 6.1 — International Brazilian Jiu-Jitsu Federation, June 2024

Read next