the amateur wrestling community and maybe the entire sports community across the world were 
 shocked by the deaths of 3 college wresters in the usa in six weeks in 1997 .
the deaths of 
 the athletes were attributed by autopsy to weight - loss performed in a short time the victims 
 having undergone dehydration of up to 15%1 . following these deaths in 1997 , the national collegiate athletic 
 association ( ncaa ) initiated and developed new safety precautions in order to prevent unsafe 
 weight practices2 .
after studies of this 
 subject , ncaa decided that competition - weighing should be conducted nearer to the 
 competitions and new weight classes should be determined by adding nearly + 3  kg to each 
 weight class3 .
besides , ncaa recommended 
 that weekly weight - loss should not exceed 1.5% of body weight as a part of the wrestling 
 weight certification ( wwc ) program4 . 

however , the most important reason why athletes lose weight is that they want to compete in 
 the lowest weight - class possible , and they think that the time between weighing and 
 competition ( ~16 hours ) is sufficient for rehydration after dehydration5 .
nevertheless , studies report that this time period of ~16 
 hours is not enough to regain the body - weight lost6 and dehydration decreases athletes performances , too7 .
it was reported that when athletes of 
 particularly combat sports such as judo , karate , boxing and wrestling perform excessively 
 severe dehydration in a short time ( 17 days ) , they undergo some hematologic changes8 , 9
. 
 there would be changes not only in posm levels , but also in na , bun 
 and glucose levels due to posm10 , 11 .
it was reported that athletes who perform 
 weight - loss before competitions undergo not only change their hydration status , but also 
 experience health problems such as sleep disorders , learning and memory difficulties , 
 anxiety , depression , irregular body temperature , vasoconstriction , low sexual performance 
 and dysfunctions in skeletal muscles12 .
skeletal muscle damage can be hematologically detected by analyzing serum levels of ck , and 
 such indicators as ldh , ast and alt enzymes in the cells of many tissues13 .
the most important indicator of skeletal 
 muscle damage is serum ck level , because ck in skeletal muscle tissues is the enzyme that 
 exists in higher amounts in the sarcolemma and mitochondrial cells of healthy muscle cells , 
 and is primarily responsible for regulating anaerobic metabolism14 .
observing serum ck and ldh levels may provide useful 
 information about the status of the muscles and their adaptation to physical load because 
 serum ck and ldh levels demonstrate the degree of metabolic adaptation of skeletal muscles 
 to physical exercise .
these values increase considerably after intense exercise15 . in physical tissue damage and other inflammatory conditions
, c - rp is the main acute phase 
 protein and a very sensitive and objective indicator16 , 17 .
indeed , abramson and 
 vaccarino reported that the c - rp level increased after one exercise dependent on the 
 duration and intensity of the exercise18 . 
 on the other hand , booth et al .
reported that c - rp , which was one of the indicators studied 
 in a 12-day military exercise , was 5.005.9 
it was also reported that the serum c - rp level of athletes increased 
 with one exercise protocol20 , but in 
 prospective studies ; that the serum c - rp level of the athletes decreased21
. there are studies in literature of dehydration , skeletal muscle damage and inflammation 
 among elite wrestlers22,23,24 .
however , no 
 study has been conducted to determine whether skeletal muscle damage or inflammation occur 
 with dehydration .
accordingly , the present study aimed to identify weight - loss and hydration 
 levels before competitions among elite wrestlers and explore skeletal muscle damage and 
 inflammation levels after dehydration .
trainers and athletes will benefit from information 
 on skeletal muscle damage and inflammation levels caused by dehydration .
the study subjects were 72 volunteer elite wrestlers who competed in the turkish 
 inter - university wrestling championship a division , who had at least 5  years sport 
 experience and did at least one exercise on a daily basis .
the participant athletes were 
 asked not to use any kinds of medicine or ergogenic aids within 48 hours before 
 competition - weighing in order to ensure standardization of the subjects and those who used 
 medicines or ergogenic aids were excluded from the study . during the study period ,
no 
 disease that could affect the blood values of the athletes was detected , but three athletes 
 were excluded from the study because their ck levels were above 1,000 u / l ( hyper - responder ) 
 and their values were considered as lost data .
the study was completed with 69 elite 
 wrestlers ( 22.512.49  years , 174.546.59  cm , 78.9815.87  kg and bmi 
 25.733.77 
the details of dehydration protocols ( how long , between which time - periods , with what 
 methods the elite wrestlers achieved weight - loss ) were datails of dehydration protocols . 

wrestlers reported that they lost weight 17 days before competitions through food and fluid 
 restrictions , sauna and exhausting exercises . in the literature
, euhydration is accepted to 
 have a reference range of 280290 mosm / l .
thus , wrestlers with posm 290 were 
 assigned to the dehydrated group and those with posm > 290 to the not 
 dehydrated group25 .
dehydration was 
 calculated using the formula below : posm = ( 2 * na)+(bun/2.8)+(glucose/18)26 .
determined 1% of dehydration as satisfactory dehydration , > 13% of 
 dehydration as mild dehydration , > 35% of dehydration as high dehydration , and > 5% of 
 dehydration as severe dehydration27 .
the 
 percentage of body weight - loss ( pbwl ) calculation was performed using the formula below : body weight change=[(pre - body weight  post - body weight)/pre - body weight ]  100 . with the help of specialists , 5 cc of blood
was drawn from the forearm veins of the 
 participant wrestlers into 8.5  ml tubes of a vacuatiner blood collection system at the 
 competition place and at the weighing time ( one day before the competition , between 06:00 
 and 06:30 pm ) and transported to the laboratory for centrifugation .
the blood samples were centrifuged with a nve nf-400 for 5 minutes at 4,000 rpm . for each 
 athlete ,
serums extracted from blood was preserved in two different eppendorf tubes under 
 20  c until the time of analysis . on the day of the analysis
biochemical analyses [ hydration indicators 
 ( na , bun , glucose ) and analyses of skeletal muscle damage indicators ( ast , 
 alt , ldh , ck ) ] were performed using a beckman coulter au2700 plus biochemical auto - analyzer 
 with beckman coulter kits , while hormone analyses were roche hitachi cobas e601 
 auto - analyzer with roche kits .
c - rp analyses were performed using a beckman coulter immage 
 800 nephelometer autoanalyzer with roche kits .
the independent samples t 
 test was used to compare pairwise group variables that followed a normal distribution , and 
 anova was used for more than two groups . following variance analyses ; lsd multiple 
 comparison test was employed in order to detect which measurement results caused the 
 differences .
the responses to the questionnaire show that 55.07% of the elite wrestlers underwent fast 
 weight - loss just before the competition ( 17 days ) ( 4.55%1.87 ) .
the wrestlers who underwent 
 fast weight - loss had higher levels of posm ( 296.053.14 ) above the upper limit of 
 reference value ( over 290 ) and suffered from dehydration .
when intergroup hydration 
 indicators were assessed , it was found that the na , bun and pbwl levels of the 
 wrestlers who were dehydrated were higher than those of the wrestlers who were not 
 dehydrated ( p<0.05 ) , but no differences existed between the groups in terms of glucose 
 levels ( p>0.05 ; table 1table 1.comparison of hydration indicators of wrestlers in terms of hydration 
 statusnhydration statusreference range 
 na ( mmol / l)31dehydrated136146142.51.6**38not dehydrated137.52.7bun ( mg / dl)31dehydrated82016.43.4 * 38not dehydrated14.33.6glucose ( mg / dl)31dehydrated7410697.015.838not dehydrated97.112.5posm ( mosm / l)31dehydrated280290296.13.1**38not dehydrated285.35.2pbwl ( % ) 31dehydrated-4.61.9**38not dehydrated1.01.3*p<0.05 , * * p<0.01 , : mean ,  : standard deviation , na : sodium , 
 bun : blood urea nitrogen , posm : plasma osmolarity , pbwl : percentage of body 
 weight loss ) .
* p<0.05 , * * p<0.01 , : mean ,  : standard deviation , na : sodium , 
 bun : blood urea nitrogen , posm : plasma osmolarity , pbwl : percentage of body 
 weight loss when skeletal muscle damage and inflammation differences of the elite wrestlers were 
 examined in relation to hydration status , differences in ast , ldh and ck levels ( p<0.05 ) 
 were found , whereas no differences existed between the groups in terms of alt and c - rp 
 levels ( p>0.05 ) .
although there were differences between the groups in terms of ast 
 ( upper limit : 50 u / l ) and ldh ( upper limit : 248 u / l ) values , these values were within the 
 reference ranges .
however , ck levels ( upper limit : 171 u / l ) of both groups were higher than 
 the reference range ( table 2table 2.comparison of skeletal muscle damage and inflammation indicators of the wrestlers 
 in terms of posm levelsnposm ( mosm / l)reference range 
 ast ( u / l)31dehydrated05024.96.3 * 38not dehydrated21.54.5alt ( u / l)31dehydrated05014.29.038not dehydrated14.07.3ldh ( u / l)31dehydrated0248207.237.2 * 38not dehydrated185.827.6ck ( u / l)31dehydrated0171421.0174.0**38not dehydrated175.880.7c - rp ( mg / dl)31dehydrated00.60.30.338not dehydrated0.30.3*p<0.05 , * * p<0.01 , ast : aspartate aminotransferase , alt : alanine 
 aminotransferase , ldh : lactate dehydrogenase , ck : creatine kinase , c - rp : c - reactive 
 protein , posm : plasma osmolarity ) .
* p<0.05 , * * p<0.01 , ast : aspartate aminotransferase , alt : alanine 
 aminotransferase , ldh : lactate dehydrogenase , ck : creatine kinase , c - rp : c - reactive 
 protein , posm : plasma osmolarity according to the classification made by casa et al . when investigating skeletal muscle 
 damage and inflammation indicators of the athletes .
there were differences between the 
 groups in terms of ast , ldh , and ck levels ( p<0.05 ) , but there were no differences 
 between the groups in terms of alt and c - rp levels ( p>0.05 ; table 3table 3.comparison of skeletal muscle damage and inflammation indicators of the wrestlers 
 in terms of pbwl classificationnpbwl ( % ) classification 
 ast ( u / l)22% 0122.04.318% > 1319.95.019% > 3525.65.510% > 526.35.6alt ( u / l)22% 0113.65.918% > 1314.17.619% > 3515.311.910% > 513.13.2ldh ( u / l)22% 01182.624.118% > 13188.038.619% > 35203.225.810% > 5222.241.1ck ( u / l)22% 01191.689.618% > 13214.4125.119% > 35364.5170.810% > 5472.9226.3c - rp
ast : aspartate 
 aminotransferase , alt : alanine aminotransferase , ldh : lactate dehydrogenase , ck : 
 creatine kinase , c - rp : c - reactive protein , pbwl : percentage of body weight loss ) .   represents the differences among the groups .
ast : aspartate 
 aminotransferase , alt : alanine aminotransferase , ldh : lactate dehydrogenase , ck : 
 creatine kinase , c - rp : c - reactive protein , pbwl : percentage of body weight loss
generally , many athletes perform fast weight - loss just before competitions ( within 17 
 days ) so that they can adapt themselves to different weight classes or compete against 
 rivals who are less strong and weaker than them in order to gain advantage .
weight loss 
 results in dehydration among the athletes by affecting their hydration levels negatively . 

studies of dehydration report that dehydration can be detected with urine specific gravity 
 ( usg ) as well as serum posm2 , 28 .
when the posm value is 290 , 
 hydration is considered normal ( euhydration ) , when it is > 290 , hydration is lower than 
 the normal level ( dehydration)25 . in the 
 present study , 55.07% of the elite wrestlers underwent fast weight - loss just before the 
 competition ( 17 days ) ( table 1 ) .
the level of 
 posm of the wrestlers who underwent fast weight - loss was above the reference 
 range ( upper limit : 290 ) ( 296.053.14 ) and they suffered dehydration of 4.55% .
these results 
 of posm level of the wrestlers were similar to the results of usg29 , 30 .
serum na and bun levels were higher among the dehydrated wrestlers due to the 
 increase in posm , but no differences were seen in their glucose values ( table 1 ) . in the literature
mmol / l . when the na 
 concentration in a blood sample is 135 
mmol / l it is defined as hyponatremia , and when it is 
 145 , it is defined as hypernatremia31 . 

it has been reported that the na+ concentration generally remains high due to long - term 
 physical activities and excessive sweating and deficiency in all body fluids , and that 
 na gradually increases with time32 , 
 33 .
it has been recommended that during 
 exercises , athletes should keep serum na concentration within the reference 
 range through a controlled diet34 , 
 otherwise nervousness , over - reaction , lethargy , muscle contraction , spasticity , convulsions , 
 coma and even mortality may occur .
it is our opinion that the differences in bun values resulted from the fact that wrestlers 
 did long - term exhausting exercises and/or adhered to food and fluid restriction programs for 
 dehydration . since bun is closely associated with the metabolic functions of the liver , and 
 the filtrating and excreting functions of the kidneys , dehydration may increase35 . indeed ,
the study of mashiko et al . 
 reported that according to measurements before and after a 20 day camp , rugby players lost 
 weight and as a result their bun levels decreased owing to weight loss36 .
the fact that there were no differences in the glucose values of the dehydrated wrestlers 
 made us think that adrenaline increased by exercises converts glycogens stored in liver into 
 glucose and glucose flows into blood with the help of glucagons and , as a result , regulates 
 blood glucose levels .
differences in na and bun values affect posm 
 values of the athletes and change their hydration status .
it is stated that dehydration of 
 23% causes cognitive disorders , irregular body temperature , cardiovascular dysfunctions as 
 well as reduced endurance and weakens muscle strength37,38,39 .
there were significant differences in terms of the damage to skeletal muscles between the 
 dehydrated wrestlers and not dehydrated wrestlers .
the 
 differences between the hydration levels and the skeletal muscle damage was determined 
 according to the classification of casa et al . , and in our study it was noted that there 
 were significant differences in ast , ldh and ck , but no differences were found in alt values 
 ( tables 2 and 3 ) between the two groups . in the 
 study of nathwaniet
et al . , it was reported that serum levels of ck , ldh , ast , alt increased 
 following muscle damage13 . under normal 
 conditions ,
these elevated levels may be tolerated by the athletes with nutritional and 
 relaxation programs , but among the dehydrated athletes , metabolism consumes low levels of 
 carbohydrate due to food and fluid restrictions and uses an energy combination of fat and 
 proteins ; thus , glucose inhibition occurring with high plasma and free fat acids suggest 
 that the damage to the muscles of the wrestlers would continue40 , 41 . in clinical practice ,
ck , ldh , ast , alt were commonly used for the diagnosis of skeletal 
 muscle diseases and skeletal muscle tissue damage42 .
the ldh level is accepted to 
 be a specific indicator of fatigue44 , 45 .
ast , being a cytoplasmic and 
 mitochondrial enzyme , may increase in many clinical disorders , but alt has been reported to 
 be a specific indicator of liver damage13 . in our study , serum ck and ldh levels , important damage indicators , 
 were higher in the dehydrated group than in the not dehydrated group . among the dehydrated 
 wrestlers , the high level of serum ck would have affected their performance negatively as 
 well as restricted their movements because of muscle pains .
it is also possible that the 
 high level of serum ldh may cause wrestlers to be reluctant and/or unwilling for the next 
 exercise .
when aminotransferases were investigated , levels of ast and alt were increased . 
 however , while there was a significant difference in ast levels , no significant difference 
 was seen in alt level , which demonstrates that ast exists in higher amounts in skeletal 
 muscles than alt .
serum levels of all these damage indicators reduced after exercises and 
 correlated with relaxation and feeding after exercises46 .
all of the participant wrestlers reported that they did daily 
 exercises and training . therefore ; it is our opinion that the high level of skeletal muscle 
 damage among the dehydrated wrestlers was caused by food and fluid restriction following 
 exercises .
c - rp is a major acute phase reactant that increases acutely and quickly in response to 
 tissue damage and infection47 . in a 
 systematic study of c - rp , it was found that as an acute phase response , c - rp temporally 
 increased after a single exercise protocol among trained athletes . however , in prospective 
 studies , it was demonstrated that c - rp ( pretest - posttest ) levels of the exercise groups 
 reduced .
in other words : although physical activity increased c - rp levels , chronic physical 
 exercises reduced c - rp levels48 .
c - rp levels of the participant athletes of both groups were low and no difference existed 
 between the groups .
considering the fact that these athletes had a sportive experience of at 
 least five years , it was expected that they would have increased tissue oxygenation because 
 of having regularly exercised for years .
uww ( united world wrestling ) shortened the resting - time in competitions of the wrestling 
 championships , aiming at muscle endurance among the wrestlers . in a wrestling tournament , 

the qualifications , 
 semi - finals and even finals , time between bouts will be short , and resting - time not be 
 sufficient for full recovery , lowering the performance of wrestlers who lose weight . 

fast and/or higher levels of weight loss before a competition produced 
 differences in wrestlers hydration indicator levels .
damage in skeletal muscles of the 
 dehydrated wrestlers was greater than in those hydrated , but no difference was found in the 
 inflammation levels of the groups . if it is necessary to lose weight before a competition , 
 athletes should do it in a way to achieve a gradual and extended weight loss over a period 
 of time depending on the weight loss targeted .
in addition , while athletes are losing 
 weight , they should keep levels of hydration and skeletal muscle damage indicators within 
 their reference ranges through ergogenic aids .
thus , ergogenic aids will play a mediator 
 role for wrestlers wishing to demonstrate maximum performance and to lead a healthy 
 life .
 [ purpose ] the present study aimed to identify weight - loss and hydration levels before 
 competitions among elite wrestlers and determine the skeletal muscle damage and 
 inflammation levels after dehydration . 
 [ subjects ] seventy - two elite wrestlers who 
 participated in the turkish wrestling championship . [ methods ] with the help of 
 specialists , 5 cc of blood were drawn from the forearm veins of the wrestlers . 
 laboratory 
 analyses of na+ , bun , glucose , ck , ldh , ast , alt , c - rp levels were performed . 
 using a mathematical formula for hydration 
 the posm levels of the athletes were 
 calculated . 
 [ results ] the wrestlers were divided into two groups based on hydration 
 status . 
 there were significant correlations between hydration indicators of 
 na+ , bun and pbwl values . 
 there were significant differences between ast , ldh , 
 ck values and skeletal muscle damage indicators of the two groups , but there were no 
 significant differences between the inflammation levels and c - rp values of the groups . 
 [ conclusion ] no differences existed in inflammation levels among the wrestlers , although 
 dehydrated wrestlers suffered from higher level of skeletal muscle damage than wrestlers 
 who were not dehydrated . 
INTRODUCTION
SUBJECTS AND METHODS
RESULTS
DISCUSSION