Sauna Suits and Hot Water Immersion: The Evidence

The hot bath, the sauna and the plastic suit are the three tools at the centre of fight-week weight cutting, and almost everything written about them falls into one of two registers: instructional, with volumes and timings and water temperatures, or condemnatory, with no numbers at all.

The literature occupies neither. It names these methods, describes a range of body mass they can move, and attaches a condition to that range in the same sentence. And in one controlled crossover study, it tested the single most widely repeated piece of folklore about them — that Epsom salt in the bath pulls more water out — and found it did not.

This article is what has actually been measured. It is not a protocol, and the reason is not squeamishness: the source material attaches a supervision requirement to these methods explicitly, and there is no published figure describing what is acceptable to attempt without it. The absence is information.

~2–4%

Body mass the ISSN position stand describes acute water-loss strategies as moving within 24 h of weigh-in — in the same sentence as "with appropriate supervision"

Ricci et al., ISSN position stand, J Int Soc Sports Nutr 2025;22(1):2467909

2.7%

Body mass lost during a two-hour hot-bath protocol in 13 male MMA athletes, out of ~5.3% across the whole rapid-loss process

Connor et al., Eur J Appl Physiol 2022;122(10):2243–2257

~14%

Fall in plasma volume measured at the end of that two-hour protocol

Connor et al., 2022

No difference

Effect of adding ~5% Epsom salt to the bath water on fluid loss, versus fresh water, in the same crossover study

Connor et al., 2022

What this comes down to

The 2025 ISSN position stand does name these methods. It says acute water loss strategies "including sauna, hot water immersion, and mummy wraps, can be used effectively with appropriate supervision (optimally ~2–4% of body mass within 24 h of weigh-in)". The clause and the number are in the same parenthesis and travel together.
In the best controlled study available, a two-hour hot-bath protocol moved about 2.7% of body mass — roughly half of the ~5.3% total the athletes lost across the full process.
Epsom salt made no difference. At approximately 5% weight/volume, salt water produced statistically indistinguishable fluid loss from fresh water. The authors state it plainly: fluid loss "was not augmented" by the salt.
The measurable physiological cost was plasma volume, down about 14% at the end of the protocol, with blood urea nitrogen, creatinine, sodium, chloride, haemoglobin and haematocrit all elevated.
Every one of those markers returned to baseline by the weigh-in 24–26 hours later, under a structured rehydration of 150% of mass lost across six hours plus 6–8 g/kg carbohydrate.
No performance index tested was impaired at that point — jump height, grip strength, isometric mid-thigh pull, or a three-minute all-out cycle test. That is thirteen athletes with a research team managing the recovery, and it is not a licence.
The failure mode that has actually killed people is thermal, not merely fluid. Exertional heat stroke is diagnosed above a core temperature of 40.5 °C with central nervous system dysfunction, and vapour-impermeable suits are specifically designed to prevent the evaporation that keeps core temperature down.

What these methods are, mechanically

All three do the same thing by different routes: they raise the rate at which the body loses water, and they do it by manipulating heat.

A sauna raises ambient temperature, which raises core temperature, which drives sweating. Evaporation from the skin is the body's primary cooling route, and in a dry sauna it works, so the athlete sweats and cools and sweats again.

Hot water immersion raises core temperature more efficiently than air at the same temperature, because water conducts heat roughly twenty-five times better than air. It also removes evaporative cooling entirely while the athlete is submerged, because there is no air-water interface at the skin. The typical practice, as described in the review literature, is short immersions followed by a period wrapped in warm clothing before further exposures.

Vapour-impermeable suits — plastic suits, sauna suits, mummy wraps — do not add heat. They trap it, by preventing sweat from evaporating. The athlete exercises, produces heat, and the suit blocks the mechanism that would otherwise remove it. Sweat rate rises because core temperature rises, and core temperature rises because cooling has been disabled.

That third mechanism is the one worth understanding properly, because it is the one with the worst safety record and the reason is structural. The sauna and the bath deliver heat that the athlete can step away from. The suit disables the athlete's own cooling while they generate heat internally through exercise. Those are not the same risk profile.

The condition inside the parenthesis

The most cited sentence on this subject in the current literature is from the International Society of Sports Nutrition's 2025 position stand on combat-sport weight management:

During fight week, acute water loss strategies, including sauna, hot water immersion, and mummy wraps, can be used effectively with appropriate supervision (optimally ~2–4% of body mass within 24 h of weigh-in).

Three things are in that sentence and gyms routinely repeat only one of them. The methods are named — which matters, because it means the stand is not pretending these practices do not exist. A range is given, roughly 2–4% of body mass. And the whole thing is conditioned on appropriate supervision, positioned inside the same parenthetical construction as the number.

Publishing the range without the condition is not a summarising choice. It states a claim the source does not make. And the gap it opens is not filled by anything else in the literature: there is no safe figure established for these methods attempted without supervision, at any percentage, because that is not a question the research has asked. Anyone offering you one has made it up.

For a 70 kg athlete, 4% is about 2.8 kg. For a 93 kg athlete it is 3.7 kg. Those numbers are what the range means in practice, and they are useful for understanding scale — but the scale is not the operative constraint. The constraint is who is watching.

The best controlled study we have

In 2022, Connor and colleagues published a crossover study in the European Journal of Applied Physiology that is, as far as we could establish, the most complete controlled description of a real hot-bath weight cut in MMA athletes.

Thirteen male MMA athletes with prior rapid weight-loss experience — mean age around 29.5 years, mean mass around 83 kg — completed the protocol twice: once with fresh water and once with approximately 5% weight/volume Epsom salt, in a repeated-measures crossover.

The bath protocol itself: water at approximately 40.3 °C, maintained at the participant's maximum tolerable level, in two 20-minute immersions, each followed by 40 minutes wrapped in an infrared sauna blanket — two hours in total.

The results, plainly:

Across the whole rapid weight-loss process (roughly 28–30 hours), athletes lost 5.42% of body mass in the fresh-water condition and 5.25% in the salt-water condition — about 4.35 kg and 4.22 kg respectively.
The two-hour bath protocol alone accounted for 2.17 kg and 2.24 kg — about 2.70% and 2.78% of initial body mass.

So roughly half of the total loss came from two hours in a hot bath, and the other half came from everything else the athletes did across more than a day: fluid restriction, food restriction, and whatever else the process involved.

That ratio is the first genuinely useful thing in the study. The bath is not a marginal contributor and it is not the whole cut. It is about half, concentrated into the last two hours, which is exactly the shape that makes it both effective and the point at which things go wrong.

The Epsom salt does nothing

Now the finding that ought to be better known than it is.

The two conditions in the crossover differed only in whether the bath contained approximately 5% weight/volume Epsom salt. That is a substantial concentration — the practice as commonly described uses far less — and it was maintained through the immersion, declining only slightly as water was displaced.

The authors' conclusion:

Under the conditions of this hot bath protocol, fluid loss was not augmented by the addition of ~5.0%wt/vol of Epsom salt during HWI.

Fresh water: 2.17 kg lost during the protocol. Salt water: 2.24 kg. Statistically indistinguishable, and if anything the direction is noise rather than signal. There was no difference in any of the blood markers between conditions either.

The theory behind salt baths is osmotic: a hypertonic solution outside the skin is supposed to draw water across it. The reason it does not work in practice is that skin is not a permeable membrane in the relevant sense. The stratum corneum is a lipid barrier, and the fluid that leaves during a hot bath leaves as sweat, driven by core temperature, not as osmotic transfer through the epidermis.

This is the kind of claim that circulates for decades because everybody who tries it loses weight — they lose weight because they sat in a hot bath for two hours, which works. The salt was never doing anything. It has now been tested directly against a fresh-water control in the population that uses it, and it did not.

Bags of Epsom salt are cheap and this is not the most consequential misconception in the sport. But it is a clean example of how folklore survives in combat sports: an intervention bundled with something that works, never isolated, and repeated until the bundle becomes a recipe.

What actually came off

The measurable physiological signature of the protocol was substantial and it was vascular.

At the end of the two-hour bath, blood urea nitrogen, creatinine, sodium, chloride, haemoglobin and haematocrit were all significantly elevated, and plasma volume had fallen by approximately 14%.

Plasma volume is the fluid fraction of blood. A 14% reduction means the circulating volume the heart is working with has meaningfully contracted, which is why haemoglobin and haematocrit rise — the cells have not gone anywhere, the fluid around them has. It is also why cardiovascular strain increases during heat exposure in a dehydrated state, and why the interaction between hypohydration and thermoregulation is the mechanism of concern rather than either factor alone.

For context on where that sits: the same athletes lost about 2.7% of body mass in those two hours. A loss of that magnitude producing a 14% contraction in plasma volume tells you that the fluid does not come proportionally from every compartment. The vascular space gives up more than its share, early.

The uncomfortable finding

Here is where the honest reading of this study gets more complicated than either the instructional or the condemnatory register would like.

After the protocol, athletes rehydrated on a structured plan — fluids at 150% of body mass lost over six hours, plus 6–8 g/kg of carbohydrate through the remainder of the day. By the weigh-in roughly 24–26 hours later, every disturbed blood marker had returned to baseline, and body mass was slightly above starting weight: a surplus of about 0.47 kg in the fresh-water condition and 0.69 kg in the salt-water condition.

And the performance tests — countermovement jump height, isometric hand-grip strength, isometric mid-thigh pull peak force, and functional threshold power from a three-minute all-out cycle ergometer test — showed nothing. The authors: "No indices of performance were impacted by the RWL and recovery process when compared to pre-RWL values."

That result should be reported accurately rather than argued around. Under those conditions — around 5.3% of body mass lost, more than 24 hours of recovery, and a rehydration protocol administered by a research team — the measured performance cost at the point of competing was not detectable.

Four qualifications travel with it, and all four are load-bearing.

Thirteen athletes. The authors themselves note the study was powered for its primary outcome and may be underpowered for the serial analyses.

Core temperature was not measured directly. The authors list the absence of oesophageal or rectal measurement as a limitation. The variable most relevant to the acute danger of this protocol was not recorded.

The recovery was supervised and specified. 150% of mass lost, over six hours, with a defined carbohydrate load. That is not what happens in a hotel room with a plastic bottle.

And the window was more than 24 hours. Everything in that result is contingent on a day-before weigh-in format. It transfers to nothing shorter.

The correct summary is therefore narrower than "hot baths are fine" and narrower than "hot baths destroy performance". It is: a cut of this magnitude, executed and recovered under supervision with a full day of recovery, did not measurably impair these four performance measures in thirteen men. Anything beyond that is extrapolation.

The risk is thermal

The failure mode that has actually killed combat athletes is not gradual dehydration. It is heat.

Exertional heat stroke is a medical emergency, diagnosed when core body temperature exceeds 40.5 °C (105 °F) with central nervous system dysfunction. Rectal temperature is the only method that gives an immediate and accurate core measurement in an exercising person — a point the athletic training literature makes repeatedly, because oral, tympanic and axillary measurements are unreliable in exactly this situation and produce falsely reassuring numbers.

The treatment priority is to lower core temperature as fast as possible, ideally within the first thirty minutes of collapse, using cold water immersion with the water continuously stirred.

Now apply that to the methods. A vapour-impermeable suit is a garment designed to prevent evaporative cooling. Exercise generates heat. The two together produce the fastest available route to a dangerous core temperature in an otherwise healthy person, and they do it in an athlete who is also fluid-depleted, which impairs both sweating and the cardiovascular response to heat.

The clinical picture that results is easy to mistake for the ordinary misery of a cut. Fatigue, confusion, irritability, difficulty communicating. Central nervous system dysfunction is the diagnostic criterion, and in a context where everybody expects a cutting athlete to be miserable and vague, the signal is buried in the noise.

That is the argument for supervision restated in concrete terms. Not "someone to encourage you". Someone whose job is to notice a change in mental state and who has a rectal thermometer and a tub of cold water, because the difference between a bad afternoon and a fatality is measured in minutes.

What happened in 1997

The reason wrestling has a weight-certification programme and other combat sports do not is a five-week period between 7 November and 9 December 1997, when three previously healthy collegiate wrestlers died in three states during rapid weight loss to qualify for competition.

The Centers for Disease Control and Prevention reported the cluster in Morbidity and Mortality Weekly Report under the title "Hyperthermia and Dehydration-Related Deaths Associated With Intentional Rapid Weight Loss in Three Collegiate Wrestlers — North Carolina, Wisconsin, and Michigan, November–December 1997". In the hours before their weigh-ins, each had engaged in a similar regimen: vigorous exercise in a hot environment while wearing vapour-impermeable suits, with food and fluid restricted.

Hyperthermia is the first word in the title, and it is not decorative. These were not primarily deaths from dehydration in the sense of gradual fluid loss. They were deaths from heat generated by exercise and trapped by clothing in athletes whose cooling capacity was already compromised.

The NCAA's own weight-management documentation names them as the origin of its programme, stating that the emphasis on hydration "is consistent with the stimulus for this program, three fatalities involving dehydration." The structure that emerged from those deaths is described in wrestling weight certification, and it attacks the problem at the level of the athlete's legal floor rather than at the level of what happens in the sauna.

Sauna, bath and suit are not interchangeable

The position stand names all three in one list, which invites the assumption that they are variations on a theme. They differ in ways that matter.

Heat transfer rate. Water conducts heat far faster than air, so hot water immersion raises core temperature more quickly than a sauna at a comparable temperature. That makes it more efficient and gives less warning.

Cooling availability. In a sauna, evaporation still functions, which provides real if limited cooling. In water, it does not function at all while submerged. In a vapour-impermeable suit, it is deliberately disabled while the athlete is producing heat internally.

Exertion. The bath and the sauna are passive. The suit is almost always used during exercise, which adds metabolic heat production to an environment already designed to prevent heat loss. That combination is the one present in the 1997 cases.

Exit speed. You can step out of a sauna in a second. You can get out of a bath in a few. Getting out of a wrapped suit while confused takes longer than any of them, and confusion is a diagnostic criterion for the thing that would make you need to.

None of this ranks them by safety in a way that produces a recommendation, and this article is not going to produce one. It ranks them by mechanism, which is what lets a supervising professional make an informed choice.

Where all of this stops applying

Every figure above assumes a recovery window on the other side of the scale.

The 2–4% range in the position stand is described within 24 hours of weigh-in, in a context where the athlete then has time to rehydrate. The Connor study's performance findings depend entirely on 24–26 hours of structured recovery. The regain figures in the broader literature were measured across day-before formats.

In competition formats without that window, none of it transfers. IBJJF grappling weighs athletes essentially immediately before they compete. IFMA muaythai runs a competition weigh-in every morning with bouts starting no earlier than three hours later, and disqualifies an athlete found more than 5% above their class before the contest. Judo adds a random weight check on competition morning with the same 5% ceiling. In each of those, the acute phase has nothing to be acute for — and in two of them, the regain it exists to produce is itself the disqualifying event.

Format determines whether any of this is a coherent question before percentage determines the answer. That is the single most useful ordering principle in the subject, and it is covered from the other direction in how much weight you can cut before a fight.

What we could not verify

The individual case detail of the 1997 deaths. The CDC's hosted copy of the MMWR report returned an access error during research, and we did not read the primary text. We describe the cluster at the level the indexed record and title support — three deaths, three states, 7 November to 9 December 1997, exercise in heat in vapour-impermeable suits with food and fluid restricted — and do not reconstruct clinical detail beyond it.
Whether the Connor findings generalise. Thirteen male MMA athletes with prior rapid-loss experience, supervised rehydration, no direct core temperature measurement, and a study the authors describe as potentially underpowered for its serial analyses. It is the best controlled description available and it is one study.
Any dose-response relationship for these methods. We found no published work establishing what magnitude of acute loss by these methods produces what magnitude of risk, in any population. There is no safe figure established for unsupervised use and its absence is not an invitation to estimate one.
Lower Epsom salt concentrations. The study tested approximately 5% weight/volume against fresh water. We have no basis to claim anything about other concentrations, though a null result at a high concentration does not encourage a hypothesis about lower ones.
Nothing here is specific to you. Not your division, your body composition, your heat tolerance, your medical history, or your weigh-in format.

Questions fighters ask

Do hot baths actually work for cutting weight?

Yes, and the magnitude has been measured. In a crossover study of thirteen male MMA athletes, a two-hour protocol of two 20-minute immersions at around 40.3 °C, each followed by 40 minutes wrapped in an infrared sauna blanket, removed about 2.2 kg — roughly 2.7% of body mass, or about half of the ~5.3% those athletes lost across the whole rapid weight-loss process. The 2025 ISSN position stand describes acute water loss strategies including hot water immersion at optimally around 2–4% of body mass within 24 hours of weigh-in, and conditions that figure on appropriate supervision in the same sentence.

Does Epsom salt in the bath help you cut more weight?

No. A controlled crossover study tested a hot-bath protocol with approximately 5% weight/volume Epsom salt against the identical protocol in fresh water, in the same thirteen athletes. Fluid loss was statistically indistinguishable — about 2.17 kg fresh water versus 2.24 kg salt water — and there were no differences in blood markers between conditions. The authors state that fluid loss was not augmented by the addition of the salt. The osmotic theory behind the practice does not hold because skin is a lipid barrier, and the fluid that leaves during a hot bath leaves as sweat driven by core temperature.

How much body mass do sauna suits remove?

Published work does not isolate suits from the rest of a cutting process well enough to give a clean figure, and this article will not invent one. What is documented is that the whole class of acute water-loss methods — sauna, hot water immersion and wraps together — is described in the 2025 ISSN position stand at optimally around 2–4% of body mass within 24 hours of weigh-in, with appropriate supervision. What is separately documented is that vapour-impermeable suits worn during exercise in heat were the common feature of three collegiate wrestling fatalities in 1997, which is a more useful fact about them than a percentage.

Is a sauna suit dangerous?

The mechanism that makes it effective is the mechanism that makes it dangerous, which is unusual and worth understanding. A vapour-impermeable suit works by preventing sweat from evaporating, and evaporation is the body's primary cooling route. Worn during exercise, it disables cooling while the athlete generates metabolic heat. Exertional heat stroke is diagnosed above a core temperature of 40.5 °C with central nervous system dysfunction, and a fluid-depleted athlete has reduced capacity to both sweat and circulate. Three collegiate wrestlers died in 1997 using exactly this combination.

What temperature should a hot bath be for a weight cut?

This article does not give protocol figures, and the reason is that the source material attaches a supervision requirement to these methods that no article can satisfy. What the research reports, descriptively, is that the Connor study used water at approximately 40.3 °C maintained at each participant's maximum tolerable level, under research supervision, with a defined immersion and wrapping structure. That is a description of what was studied, not an instruction. Core temperature was not directly measured even in that study, which the authors list as a limitation — and core temperature is the variable that determines the risk.

Does cutting weight this way hurt performance on fight night?

The best controlled evidence is more equivocal than either side of this argument usually admits. In the Connor study, after about 5.3% body mass loss and 24–26 hours of structured recovery — fluids at 150% of mass lost over six hours plus 6–8 g/kg carbohydrate — no measured performance index was impaired: not jump height, grip strength, isometric mid-thigh pull, or three-minute all-out cycling power. Blood markers had also normalised. That is thirteen athletes with a research team managing the rehydration and more than a day of recovery. It does not establish that unsupervised cuts of that size, or shorter recovery windows, produce the same result.

What happens to your blood during a hot-bath cut?

It concentrates. In the Connor study, at the end of the two-hour bath protocol, blood urea nitrogen, creatinine, sodium, chloride, haemoglobin and haematocrit were all significantly elevated, and plasma volume — the fluid fraction of blood — had fallen by approximately 14%. Haemoglobin and haematocrit rise because the cells remain while the fluid around them does not. A contracted plasma volume increases cardiovascular strain during heat exposure, which is why the interaction between hypohydration and thermoregulation, rather than either alone, is the mechanism of concern.

How long does it take for those markers to recover?

In the Connor study, all of them had returned to baseline values by the weigh-in roughly 24 to 26 hours after the protocol, following structured rehydration. Body mass was slightly above starting weight at that point. This has an important consequence for testing: a hydration or blood check at a day-before weigh-in is measuring the recovery rather than the cut, which is one reason the promotions that test seriously test repeatedly across fight week rather than once at the scale.

Are sauna, hot water immersion and sweat suits the same thing?

No, though the position stand lists them together. Water conducts heat roughly twenty-five times better than air, so immersion raises core temperature faster than a sauna at the same temperature and gives less warning. Evaporative cooling still functions in a sauna and does not function at all in water or inside a vapour-impermeable suit. And the suit is almost always used during exercise, adding metabolic heat production to an environment designed to prevent heat loss — the combination present in the 1997 fatalities. They differ in heat transfer rate, in available cooling, and in how quickly you can get out.

What does "appropriate supervision" actually mean here?

In practical terms, someone whose job is to monitor the athlete rather than encourage them, who can recognise central nervous system dysfunction as a medical sign rather than as the normal misery of a cut, and who has the means to measure core temperature and to cool aggressively. Rectal temperature is the only method giving an immediate accurate core reading in an exercising person; oral and tympanic measurements are unreliable in this situation. The treatment priority for exertional heat stroke is cold water immersion within the first thirty minutes of collapse. Supervision means having that capability present, not having company.

Is there a safe amount of weight to cut this way?

There is no safe figure established for these methods used without supervision, at any percentage, in any population — and that absence is a finding rather than a gap for a coach to fill. The published range, roughly 2–4% of body mass within 24 hours of weigh-in, appears in the literature only ever attached to a supervision requirement in the same sentence. Someone who offers you a number for what you can do alone has produced it from nowhere. The honest answer is that the question the literature has answered is a different question from the one most athletes are asking.

Do these methods work if I weigh in on the day I compete?

The methods still remove fluid; what changes is that there is no recovery window to put it back into, so the cost is paid during the contest rather than absorbed beforehand. Every figure in the acute-loss literature — the 2–4% range, the regain figures, the Connor performance findings — was described in formats with a day or more between scale and competition. Under IBJJF, IFMA muaythai or judo rules the window is hours or minutes, and in the latter two a large regain is itself disqualifying. In those formats the coherent plan is a longitudinal descent that arrives at the division and holds.

Why did three wrestlers die in 1997?

Between 7 November and 9 December 1997, three previously healthy collegiate wrestlers in North Carolina, Wisconsin and Michigan died during programmes of rapid weight loss to qualify for competition. The CDC reported the cluster in Morbidity and Mortality Weekly Report in 1998 under a title beginning "Hyperthermia and Dehydration-Related Deaths". In the hours before their weigh-ins each had engaged in vigorous exercise in a hot environment while wearing vapour-impermeable suits, with food and fluid restricted. The NCAA's weight-certification programme, which sets a legal minimum weight per athlete, was built directly in response and names those three fatalities as its stimulus.

Sources

Sourced to

International society of sports nutrition position stand: nutrition and weight cut strategies for mixed martial arts and other combat sports — Ricci AA et al., Journal of the International Society of Sports Nutrition, 2025;22(1):2467909. DOI 10.1080/15502783.2025.2467909, PMID 40059405
Effect of rapid weight loss incorporating hot salt water immersion on changes in body mass, blood markers, and indices of performance in male mixed martial arts athletes — Connor J, Germaine M, Gibson C, Clarke P, Egan B, European Journal of Applied Physiology, 2022;122(10):2243–2257. DOI 10.1007/s00421-022-05000-7, PMID 35833967
Effect of rapid weight loss incorporating hot salt water immersion (publisher record) — Springer Nature, European Journal of Applied Physiology, 2022
Acute-Weight-Loss Strategies for Combat Sports and Applications to Olympic Success — Reale R, Slater G, Burke LM, International Journal of Sports Physiology and Performance, 2017;12(2):142–151. DOI 10.1123/ijspp.2016-0211
Hyperthermia and dehydration-related deaths associated with intentional rapid weight loss in three collegiate wrestlers — North Carolina, Wisconsin, and Michigan, November–December 1997 — Centers for Disease Control and Prevention, MMWR Morb Mortal Wkly Rep 1998;47(6):105–108, PMID 9480411
National Athletic Trainers' Association Position Statement: Exertional Heat Illnesses — Casa DJ et al., Journal of Athletic Training 2015;50(9):986–1000. DOI 10.4085/1062-6050-50.9.07
Muscle contraction velocity, strength and power output changes following different degrees of hypohydration in competitive olympic combat sports — Pallarés JG et al., Journal of the International Society of Sports Nutrition, 2016;13:10. DOI 10.1186/s12970-016-0121-3, PMID 26957952
An alternative structured weight management protocol to rapid weight loss in mixed martial arts: a prospective interventional study — Maurício CA et al., Frontiers in Nutrition, 8 October 2025;12:1581698. DOI 10.3389/fnut.2025.1581698, PMID 41132567
2025-26 NCAA Men's Wrestling Weight Management Program Packet — National Collegiate Athletic Association, 13 August 2025; Supplement No. 9 naming the 1997 fatalities as the programme's stimulus
IFMA Rules and Regulations v3.057 — International Federation of Muaythai Associations, 11 May 2026; Rule 11, cited for the daily weigh-in and 5% pre-contest provision
Sport and Organisation Rules of the International Judo Federation, version 14.08.2026 — International Judo Federation, 14 August 2026; Rule 6.3, cited for the 5% random weigh-in ceiling

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Sauna suits and hot water immersion