110 Obminski.qxp - Medycyna Sportowa
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110 Obminski.qxp - Medycyna Sportowa
Medycyna Sportowa © MEDSPORTPRESS, 2008; 1(6); Vol. 24, 11-20 2 1 2 POZIOM KORTYZOLU I TESTOSTERONU W SUROWICY KRWI ORAZ ZDOLNOŒCI PSYCHOMOTORYCZNE U BOKSERÓW W CZASIE LABORATORYJNEJ PRÓBY NA WORKU BOKSERSKIM Author’s Contribution A – Study Design B – Data Collection C – Statistical Analysis D – Data Interpretation E – Manuscript Preparation F – Literature Search G – Funds Collection PLASMA CORTISOL AND TESTOSTERONE LEVELS AND PSYCHOMOTOR ABILITIES IN BOXERS DURING A LABORATORY TASK WITH A PUNCHING BAG ibu -d istr S³owa kluczowe: bokserzy, hormony, mleczan, próba laboratoryjna Key words: boxers, hormones, lactate, laboratory task Streszczenie on al us This copy is for personal use only - distribution prohibited. - eo nly Wstêp. Cel badañ by³ potrójny: (i) zbadanie czasu reakcji z wyborem i si³y ciosu w próbie laboratoryjnej o przebiegu podobnym do 5-rundowej bokserskiej walki, (ii) zbadanie zmian stê¿enia kortyzolu (C) testosteronu (T) i mleczanu (LA) po wysi³ku, (iii) poszukiwanie zale¿noœci miêdzy hormonami a poziomem wykonania próby. Materia³ i metody. Praworêczni bokserzy, ró¿ni¹cy siê wiekiem i mas¹ cia³a, wykonali wysi³ek laboratoryjny z³o¿ony z wielu ciosów zadanych w specjalny worek bokserski. Krew kapilarn¹ pobrano rano (8:00), 3 minuty przed testem oraz w 3 i 30 minucie powysi³kowej odnowy. Czas reakcji i si³ê rejestrowano dla ka¿dego uderzenia. Wyniki. W oparciu o wszystkie obserwacje (33 osoby*5 rund=165) wykazano znacz¹ce (p<0.005) ró¿nice miêdzy œrednim czasem reakcji i si³y ciosu dla wysuniêtej (lewej) (591±81ms i 847±146 N) i dla prawej (cofniêtej) (658±67ms i 1246±215 N) rêki. W czasie powysi³kowej restytucji C wykazywa³ tendencjê rosn¹c¹, w +30 min o 21% w porównaniu do wartoœci przed testem. Wartoœæ T przed prób¹ ujemnie korelowa³a w pierwszej rundzie z czasem reakcji dla wysuniêtej (r=-0.494*) i dla cofniêtej (r=-0.418*) rêki. Po wysi³ku œrednie stê¿enie mleczanu osi¹gnê³o wartoœæ 4.7±16 mmol/L. Wnioski. Wyniki ujawni³y ró¿nice w poziomie wykonania testu pomiêdzy lew¹ i praw¹ rêk¹, a tak¿e liniow¹ zale¿noœæ pomiêdzy stê¿eniem testosteronu a czasem reakcji. Summary 7547 3 0 54 op Word count: Tables: Figures: References: y is - for pe rs Background. The objective of this study was threefold: (i) to examine choice reaction time and the force of blows in boxers who performed a laboratory task similar to a real 5-round contest, (ii) to assess changes in blood cortisol (C), testosterone (T) and lactate (LA) levels following exertion, (iii) to search possible relationships between performance and hormones. Material and methods. Right-hand amateur boxers (n=33) varied by age and body mass underwent laboratory exertion, consisting of several blows into purpose-made punching bag. Capillary blood from the earlobe was sampled in the morning (8:00), 3 minutes prior to the task, and within 3 and 30 minutes of post-task recovery. Reaction time and force were registered for each blow. Results. Based on the total number of observations (33 subjects*5 rounds=165), significant differences (p<0.005) were observed between mean reaction time and mean maximal force for forward (left) (591±81msec. and 847±146 N) and for backward (right) (658±67msec. and 1246± 215 N) hand. During post-task recovery C tended to increase, within +30 min. by 21%, in comparison to the pre-task value. In the first round, pre-task T negatively correlated with mean reaction time for forward (r=-0.494*), and for backward (r=-0.418*) hand. Mean post-task LA was 4.7±1.6 mmo/L. Conclusions. The results revealed hand-related differences in psycho-motor performances and linear relationships between T and reaction time. Th is c Adres do korespondencji / Address for correspondence dr Zbigniew Obmiñski Zak³ad Endokrynologii, Instytut Sportu 01-982 Warszawa, ul. Trylogii 2/16, tel./fax: (0-22) 834-95-07, e-mail: [email protected] Otrzymano / Received Zaakceptowano / Accepted 05.03.2007 r. 19.06.2007 r. - This copy is for personal use only - distribution prohibited. Zak³ad Endokrynologii, Instytut Spotu, Warszawa Zak³ad Konstrukcji, Instytut Sportu, Warszawa Department of Endocrinology, Institute of Sport in Warsaw Department of Engineering, Institute of Sport in Warsaw tio np roh ibit 1 ed . Zbigniew Obmiñski1(A,B,C,D,E,F), Bohdan Karpi³owski 2(A,B,C,D,E,F), Krystyna Wiœniewska1(A,B,C,D,E,F) Zaanga¿owanie Autorów A – Przygotowanie projektu badawczego B – Zbieranie danych C – Analiza statystyczna D – Interpretacja danych E – Przygotowanie manuskryptu F – Opracowanie piœmiennictwa G – Pozyskanie funduszy This copy is for personal use only - distribution prohibited. - This copy is for personal use only - distribution prohibited. - ARTYKU£ ORYGINALNY / ORIGINAL ARTICLE 11 Background W sportach walki wa¿n¹ sk³adow¹ specyficznej sprawnoœci psychomotorycznej jest czas reakcji, prosty lub z wyborem. W tych sportach wspomniany parametr w znacznym stopniu determinuje klasê sportow¹ i mo¿e przes¹dziæ o wyniku rywalizacji. Z tego powodu pomiary odpowiednich zmiennych w warunkach laboratoryjnych maj¹ du¿e znaczenie diagnostyczne. W literaturze opisano wiele relacji pomiêdzy czasem reakcji a poziomem endogennych hormonów. Na uwagê zas³uguje fakt, ¿e laboratoryjne pomiary czasu reakcji s¹ traktowane przez uczestników badañ jak test i gdy pomiary trwaj¹ dostatecznie d³ugo, powoduj¹ zmêczenie psychiczne i krótkotrwa³e reakcje biologiczne podobne do tych, które obserwuje siê po wysi³kach fizycznych. W 12-minutowej laboratoryjnej próbie, pomiary czasu reakcji w 2-sekundowych odstêpach wywo³a³y ok. 40% wzrost poziomu adrenaliny we krwi [1] i nieznaczne (o 6%) pogorszenie czasu reakcji pod koniec badania [2]. Inni autorzy odnotowali wzrost czêstoœci skurczów serca, ciœnienia krwi i przewodnictwa elektrycznego skóry. Wymienione reakcje by³y wiêksze u osób z osobowoœci¹ Typu A ni¿ Typu B [3]. Typ A reaguje równie¿ wiêkszym wzrostem kortyzolu w sytuacjach zadaniowych [4]. Wnioski ró¿nych autorów wynikaj¹ce z badañ czasu reakcji nie s¹ jednoznaczne. Wczesne badania sugerowa³y, ¿e prosty czas reakcji w pomiarach maksymalnej si³y statycznej prostownika stawu ³okciowego nie zale¿y od wytrenowania ani p³ci i dla wszystkich badanych grup wynosi³ ok. 196 milisekund [5]. Nowsze dane wskazuj¹, ¿e u sportowców wielkoœæ czasu reakcji prostej lub czasu reakcji z wyborem jest wypadkow¹ wielu zmiennych, m.in. rodzaju dyscypliny sportu i warunków pomiaru (tj. w spoczynku lub w czasie wykonywania wysi³ków o ró¿nej intensywnoœci) [6]. Widoczne s¹ równie¿ ró¿nice czasów reakcji w pomiarach dla rêki dominuj¹cej i niedominuj¹cej [7], ale u sprinterów oczekuj¹cych w blokach na start wyniki pomiarów by³y podobne dla obu dolnych koñczyn [8]. Wielokrotne pomiary czasu reakcji podczas ró¿nych wysi³ków ujawni³y zmiany tego parametru wraz ze zmianami stê¿eñ niektórych parametrów mierzonych we krwi. Obni¿enie czasu reakcji rejestrowano wraz ze wzrostem poziomu amin katecholowych (ujemna korelacja) w wysi³ku o sta³ej intensywnoœci poni¿ej progu beztlenowego [9], natomiast podczas wysi³ku o wzrastaj¹cej intensywnoœci odnotowano najpierw spadek, a potem wyd³u¿enie czasu reakcji. Krzywa opisuj¹ca zale¿noœæ czasu reakcji od stê¿enia mleczanu we krwi odpowiada³a paraboli, dla której minimalna wartoœæ czasu reakcji odpowiada³a stê¿eniu mleczanu 5.5 mmol/L [10]. Badanie to sugerowa³o, ¿e wzrost poziomu mleczanu powy¿ej wspomnianej wartoœci upoœledza czas reakcji, jednak¿e u dobrze wytrenowanych zapaœników powysi³kowe (walki sparingowe) stê¿enia mleczanu w granicach 17-20 mol/L nie wp³ynê³y negatywnie na wartoœæ wspomnianej psychomotorycznej zmiennej, co mo¿na by t³umaczyæ bardzo dobr¹ tolerancj¹ wysi³ków beztlenowych i byæ mo¿e kompensuj¹cym wp³ywem du¿ego poziomu amin katecholowych [11]. Istnieje równie¿ zwi¹zek miêdzy czasem reakcji a poziomem endogennych androgenów. Wykazano, ¿e mê¿czyŸni z wy¿szym poziomem testosteronu (w œli- In combat sports, simple or choice reaction time is an important component of psychomotor fitness. This parameter is a significant determinant of sportsmen's potential and may be predictive of competition results. Therefore, laboratory measurements of proper variables are of remarkable diagnostic significance. Numerous relations between reaction time and endogenous hormone level have been reported in literature. It is worth attention that laboratory measurements of reaction time are treated as a test by study participants; if they are too long, they cause mental fatigue and short lasting biological responses, similar to those observed following physical effort. During a 12 minute laboratory test, reaction time measurement in 2 second intervals evoked about 40% increase in blood adrenaline [1] and slight worsening of reaction time (by 6%) at the end of the study [2]. Other authors have noted the increase in heart rate, blood pressure and skin electrical conductivity. These parameter values were bigger in persons with type A personality compared to type B [3]. Type A also reacts with the increase in cortisol while performing tasks [4]. Different authors' conclusions, resulting from testing reaction time are not unanimous. The earlier studies suggested that simple reaction time during maximal static force measurement in the elbow joint extensor did not depend on training level or gender, and amounted to 196 ms for all studied groups [5]. More recent data show that the length of simple and choice reaction time is the resultant of many variables, including kinds of sport disciplines and the conditions of measurement (at rest or during effort of different intensity) [6]. We can also see the differences in reaction times during measurements for the dominant and non-dominant hand [7]; they were however similar for both lower limbs in sprinters waiting on starting blocks [8]. Multiple measurements of reaction time during different kinds of effort revealed changes in this parameter, accompanied by the changes in blood concentration of different parameters. The reduction of reaction time was noted with the increase in catecholamines (negative correlation) during effort of constant intensity, below the anaerobic threshold [9], while during effort of growing intensity, the decrease was noted prior to reaction time lengthening. The curve denoting the relationship between reaction time and blood lactate concentration corresponded to the parabola, for which the minimal reaction time value corresponded to lactate concentration of 5.5 mmol/L [10]. The study results suggest that the increase in lactate concentration above this level impairs reaction time, however in well trained sparring fighters, lactate concentration of 1720 mol/L had no negative effect on the above mentioned psychomotor variable, which could be explained by a very good tolerance to anaerobic effort and probably a compensatory effect of high catecholamine level [11]. There is also a relationship between reaction time and endogenous androgen concentration. It has been shown that simple reaction time is shorter in men with higher (salivary) testosterone concentration [12]. The inverted parabola reflects the relation between spatial imagination and free testosterone level [13]. An Th is c op y is for pe rs on al us eo nly -d istr ibu tio np roh ibit ed . Wstêp - This copy is for personal use only - distribution prohibited. - This copy is for personal use only - distribution prohibited. - This copy is for personal use only - distribution prohibited. - This copy is for personal use only - distribution prohibited. - Obmiñski Z. i wsp., Poziom hormonów oraz zdolnoœci psychomotoryczne bokserów 12 equal amount of data was collected on the effect of blood testosterone level on maximal strength or power. These data suggest that high testosterone level is favourable for strength and power development resulting from training. It is possible that for this reason, higher testosterone level in male sportsmen provides an opportunity to attain success in many sports disciplines [14-18]. In professional sportsmen, the relations between hormonal, exercise and psychometric tests are little known. During our own laboratory studies on a cohort of boxers, we tested motoric skills, specific for this discipline, reaction time and the force of blows. The aim of the study was: 1. testing reaction time and the force of blows in a punching bag during a laboratory trial with the course similar to a 5-round boxers' fight; 2. testing the effect of the above mentioned laboratory study on changes in blood cortisol, testosterone and lactate concentration; 3. attempt to determine the dependence between measured blood testosterone and lactate concentration and the level of task performance, namely mean reaction time and mean blow force. Materia³ i metody Material and methods tio np roh ibit ibu -d istr nly eo A sample of boxers (n=33) with the dominant right hand, from different weight categories (48-91 kg), aged 19-31 years, were examined at the Institute of Sport during the final stage of endurance training. After the warm up, a laboratory trial was carried out (13:00-16:00), simulating a 5-round fight – the boxers hit a punching bag (5x2 minutes with 1 minute intervals). The subjects wearing boxing gloves assumed a position typical for right handed fighters in front of the punching bag, with the left arm moved towards it and the right side of the body moved backward. They were told to hit the punching bag as quickly and as strong as possible with their right and left hand or with their both hands when they saw three kinds of light signals, randomly generated by the computer. During each round the participants struck the same number of blows in the punching bag: 16 single blows with the (right) backward hand, 20 blows – with the (left) forward hand and 20 starting series, consisting of 3 blows, struck with the left and right hand alternatingly. Each kind of blow was prompted by a different light stimulus: for the left hand – yellow light, for the right hand – red light, and for a series of blows – both lights at the same time. Reaction time was measured by a tensometric sensor from the moment when the light stimulus appeared until the maximal force value was recorded by the tensometric sensor. Light stimuli were randomly generated by the electronic system. Capillary blood was taken from the earlobe in the morning (8:00), immediately after a light warm up, 3 minutes prior to the test, and finally – 3 and 30 minutes following effort. The study was approved by the Ethical Board of the Institute of Sport in Warsaw. Blood cortisol and testosterone immunoenzymatic assay was performed using IBL-GERMANY Th is c op y is for pe rs on al us Bokserzy (n=33) o dominuj¹cej prawej rêce, z ró¿nych kategorii wagowych (48-91 kg), w wieku od 19 do 31 lat, byli badani w Instytucie Sportu pod koniec okresu treningowego kszta³tuj¹cego wytrzyma³oœæ. Wykonali oni, po rozgrzewce, próbê laboratoryjn¹ (13:0016:00) symuluj¹c¹ 5-rundow¹ walkê, tj zadawali ciosy w worek bokserski (5x2 minuty z minutowymi przerwami). Badani (w rêkawicach bokserskich) zajmowali typow¹ dla zawodników praworêcznych pozycjê boksersk¹ przed workiem, z nieco wysuniêt¹ w kierunku celu lew¹, a cofniêt¹ praw¹ czêœci¹ cia³a. Na trzy rodzaje sygna³ów œwietlnych generowanych losowo przez komputer, mieli oni zadawaæ najszybsze i najsilniejsze uderzenia lew¹ i praw¹ rêk¹ lub serie dwiema rêkami. W ka¿dej rundzie zadano w worek bokserski tê sam¹ liczbê uderzeñ: 16 pojedynczych uderzeñ rêk¹ „cofniêt¹” (praw¹), 20 „wysuniêt¹” (lew¹) i 20 serii rozpoczynaj¹cych z³o¿onych z 3 uderzeñ, na przemian lew¹ i praw¹ rêk¹. Ka¿dy rodzaj uderzenia by³ inicjowany przez inny sygna³ œwietlny: dla rêki lewej – lampka ¿ó³ta, dla prawej – lampka czerwona, a dla serii uderzeñ – obie lampki jednoczeœnie. Czasy reakcji by³y mierzone elektronicznie – od pojawienia siê sygna³u do rejestracji wartoœci maksymalnej si³y przez czujnik tensometryczny. Sygna³y œwietlne by³y generowane losowo przez uk³ad elektroniczny. Krew kapilarn¹ z p³atka ucha pobrano rano (8:00), a nastêpnie bezpoœrednio po lekkiej rozgrzewce, a tak¿e 3 minuty przed testem oraz w 3 i 30 min po wysi³ku. Badania uzyska³y zgodê Komisji Etycznej przy Instytucie Sportu w Warszawie. W surowicy krwi oznaczono stê¿enie kortyzolu i testosteronu immunoenzymatycznie zestawem fabrycznym IBL-GERMANY, a stê¿enia mleczanu, hematokrytu i hemoglobiny oznaczono we krwi spektrofotometrycznie zestawem Dr LAN- ed . nie) maj¹ krótszy czas reakcji prostej [12], podczas gdy zale¿noœæ pomiêdzy wyobraŸni¹ przestrzenn¹ a wolnym testosteronem opisuje odwrócona parabola [13]. Nie mniej danych zgromadzono na temat wp³ywu poziomu testosteronu we krwi na maksymaln¹ si³ê lub moc. Dane te sugeruj¹, ¿e wysoki poziom testosteronu sprzyja rozwojowi si³y i mocy pod wp³ywem treningów. Mo¿liwe, ¿e z tego powodu wy¿szy poziom testosteronu u mê¿czyzn w czasie zawodów sportowych w wielu dyscyplinach daje wiêksz¹ szansê sukcesu [14-18]. U wyczynowych sportowców zale¿noœci pomiêdzy równoleg³ymi wynikami badañ hormonalnych, wysi³kowych i psychometrycznych s¹ s³abo poznane. W badaniach w³asnych przeprowadzonych jednorazowo na grupie bokserów testowano w warunkach laboratoryjnych specyficzne dla tej dyscypliny zdolnoœci motoryczne, czas reakcji i si³ê ciosów. Celem badañ by³o: 1. zbadanie czasu reakcji i si³y ciosów zadawanych w worek bokserski w laboratoryjnej próbie o przebiegu podobnym do 5-rundowej walki bokserskiej, 2. zbadanie wp³ywu takiego oddzia³ywania próby laboratoryjnej o przebiegu podobnym do 5-rundowej walki bokserskiej na zmiany stê¿enia we krwi kortyzolu, testosteronu i mleczanu, 3. poszukiwanie zale¿noœci miêdzy zmierzonym we krwi stê¿eniem kortyzolu, testosteronu i mleczanu a poziomem wykonania zadania, tzn. œrednim czasem reakcji oraz œredni¹ si³¹ ciosów. - This copy is for personal use only - distribution prohibited. - This copy is for personal use only - distribution prohibited. - This copy is for personal use only - distribution prohibited. - This copy is for personal use only - distribution prohibited. - Obmiñski Z. et al., Hormone level and psychomotor skills in boxers 13 kit. Spectrophotometric blood hematocrit and hemoglobin assay was performed using Dr LANGE kit. Post exercise changes in blood volume were determined based on hematocrit and hemoglobin content according to Dill and Costil's pattern (1974). The differences between mean values of measured parameters were tested by repeated measures analysis of variance (ANOVA), while linear correlations between the parameters were tested by correlation coefficients using STATISTICA 7.1 software. Wyniki Results -d istr ibu Tables 1-2 present the results of the measurement of the mean strength of blows struck with the forward and backward hand separately, as well as mean reaction time for the backward hand and forward hand (for each of the five rounds). The comparison of mean reaction times and blow force did not reveal statistically significant differences in these values between the rounds. During the first round, reaction times were slightly shorter and the blows were slightly weaker compared to the fifth round. Therefore we can accept mean repeatability of the eo nly Tab. 1. Œrednie czasy reakcji na sygna³ œwietlny (ms) rejestrowany dla ciosów rêk¹ wysuniêt¹ (lew¹) i cofniêt¹ (praw¹) w kolejnych rundach u bokserów (n=33) Tab. 1. Mean time reaction (msec) to light signal recorded for blows performed by forward (left) and backward hand (right) in successive rounds in boxers (n=33) us for pe rs on al Tab. 2. Œrednie wartoœci maksymalnej si³y ciosów (N) wykonanych rêk¹ wysuniêt¹ (lew¹) i cofniêt¹ (praw¹) w kolejnych rundach u bokserów (n=33) Tab. 2. Mean maximal blows force (N) for forward (left) and backward hand (right) in successive rounds in boxers (n=33) - This copy is for personal use only - distribution prohibited. tio np roh ibit Wyniki pomiarów œredniej si³y ciosów zadanych osobno rêk¹ wysuniêt¹ i cofniêt¹ oraz œredni czas reakcji na sygna³ dla rêki cofniêtej i wysuniêtej (dla ka¿dej z piêciu rund) przedstawiono w Tabelach 1-2. Porównuj¹c œrednie czasy reakcji oraz si³y uderzeñ, nie odnotowano istotnych ró¿nic miêdzy rundami. W pierwszej rundzie czasy reakcji by³y minimalnie krótsze, a si³a uderzeñ nieznacznie s³absza ni¿ w pi¹tej rundzie. Zatem mo¿na uznaæ dobr¹, œredni¹ dla grupy powtarzalnoœæ wyników zmiennych w 5 rundach. Obliczenia wartoœci œrednich (n=33) w kolej- Th is c op y is Tab. 3. Stê¿enia kortyzolu (C) i testosteronu (T) w nmol/L w surowicy krwi pobranej rano (8:00) oraz przed wysi³kiem (-3 min), w 3 minucie (+3 min) i 30 minucie (+30 min) powysi³kowej restytucji u bokserów (n=33) Tab. 3. Concentrations of cortisol (C) and testosterone (T) in nmol/L in plasma samples taken in the morning (8: 00), prior to laboratory task (-3 min) and within 3 (+3 min) and 30 (+30 min) minutes of post task recovery in boxers (n=33) - This copy is for personal use only - distribution prohibited. ed . GE. Po wysi³ku zmiany objêtoœci krwi okreœlono na podstawie hematokrytu i hemoglobiny wg wzoru Dill i Costil (1974). Ró¿nice miêdzy wartoœciami œrednimi dla mierzonych parametrów testowano analiz¹ wariancji z powtarzanymi pomiarami (ANOVA), a liniowe zale¿noœci miêdzy parametrami – wspó³czynnikami korelacji z u¿yciem komputerowego programu (STATISTICA 7.1). - This copy is for personal use only - distribution prohibited. - This copy is for personal use only - distribution prohibited. - Obmiñski Z. i wsp., Poziom hormonów oraz zdolnoœci psychomotoryczne bokserów 14 variables during these five rounds as good. Calculation of the mean values (n=33) during consecutive rounds and the mean values for the entire test (n=165) showed that blows struck with the left, forward hand, although markedly faster, are weaker than the blows struck with the right hand. No statistically significant differences were shown between the force of blows and body mass (r=0.220) or between the body mass and reaction time (r=0.305). The participants' age correlated positively with the total relative (N/kg of body mass) blow force (r=0.414 p<0.05), but not with the total reaction time for both hands (r=0.198). Significant negative correlations (p<0.05) were noted between testosterone level in the morning and mean reaction time for the forward (r=-0.465) and backward (r=-0.395) hand during the whole test, and between testosterone level prior to the test and the reaction time during the first round for the forward (r=-0.494) and backward (r=-0.418) hand. No correlation was noted between testosterone or cortisol level and the force of blows, and between cortisol level and reaction time. Although the exercise did not cause a statistically significant increase in cortisol (by 44 nmol/L in +30th minute) and testosterone concentration (by 1.6 nmol/L in +3rd minute), those changes accompanied by a mere hemoconcentration during the third minute following exercise (by 1.6%) indicate slight post-exercise secretion. A low mean post-exercise lactate level (4.7 mmol/L) indicates low effort intensity. Dyskusja Discussion tio np roh ibit ibu -d istr nly eo During medical examinations, boxers focus mainly neurologists' attention (due to head injury sequelae) [19,20]. Existing research has shown that after a few days following head injuries and short lasting consciousness loss, reaction time is somehow slower and certain cognitive functions somehow impaired in boxers [21] or other sportsmen [22]. On contrary, very little attention has been paid to psychomotor fitness examination in boxers and evaluation of physiological responses to exercise during training and competition. Preparation for boxing competition consists in aerobic fitness and endurance improvement. After that, attention is focused on technical training. The intensity of such training is low and corresponds to a continuous run with the speed of 9 km/h [23]. Our study was carried out on completion of endurance training. Such training decreases resting testosterone level [24-26], what is reflected by our own study results. Surprisingly, the diurnal rhythm of this hormone is not very well marked despite relatively late hours of laboratory study commencement. Mean testosterone level before the study, measured from 1 p.m till 4 p.m, was only 15% lower compared to morning hours, so the expected speed of decrease was significantly lower than that observed in men of the same age [27] and the observed decrease in testosterone concentration in other sportsmen [28,29]. The effect of diurnal rhythmicity of cortisol concentration is clearly marked [30]. Physical exercise intensity was low during the test with a punching bag, what was manifested by a relatively low post-exercise lactate level. Contrary to this metabolic response, 421 blows struck with maximal force evoked significant hemoconcentration (3.3%) and high lactate concentration (14 mmol/L) [31]. Th is c op y is for pe rs on al us W badaniach medycznych bokserzy skupiaj¹ uwagê g³ównie neurologów (z powodu zdrowotnych konsekwencji urazów g³owy) [19,20]. Wykazano, ¿e po kilku dniach od urazu g³owy i krótkotrwa³ej utracie œwiadomoœci u bokserów [21] lub innych sportowców [22], czas reakcji jest nieco wolniejszy, a pewne funkcje poznawcze oraz pamiêæ nieco upoœledzone. Natomiast bardzo niewiele uwagi poœwiêcono na badania sprawnoœci psychomotorycznej bokserów i ocenê reakcji fizjologicznych na wykonywane przez nich wysi³ki treningowe i startowe. Przygotowania do sezonu startowego w boksie polegaj¹ na podnoszeniu wydolnoœci tlenowej i wytrzyma³oœci. Po jej uzyskaniu uwaga skupia siê na treningach technicznych, których intensywnoœæ jest niewielka i odpowiada ci¹g³emu biegowi z szybkoœci¹ 9 km/h [23]. Nasze badania przeprowadzono po zakoñczeniu treningów wytrzyma³oœci. Taki rodzaj treningów obni¿a spoczynkowy poziom testosteronu [24-26], co znalaz³o odbicie w badaniach w³asnych. Zaskakuj¹cy jest s³abo zaznaczony dzienny rytm tego hormonu, pomimo wzglêdnie póŸnej pory dnia rozpoczêcia prób laboratoryjnych. Œredni poziom tego hormonu przed prób¹, badany w godzinach 13:00-16:00, by³ jedynie o 15% ni¿szy ni¿ rano, a wiêc oczekiwana szybkoœæ spadku stê¿enia w ci¹gu dnia by³a znacznie mniejsza od tego, co obserwuje siê u zdrowych m³odych mê¿czyzn w tym wieku [27] oraz od obserwowanego ju¿ przed po³udniem spadku stê¿enia testosteronu u innych sportowców [28,29]. Bardzo wyraŸnie za to zaznaczony jest efekt dziennej rytmiki stê¿enia kortyzolu [30]. Intensywnoœæ wysi³ku fizycznego w czasie badañ na worku bokserskim by³a niedu¿a, o czym œwiadczy stosunkowo niewysoki powysi³kowy poziom mleczanu. W przeciwieñstwie do wzglêdnie niewielkiej reakcji me- ed . nych rundach oraz œrednich z ca³ego testu (n=165) wykaza³y, ¿e lewa wysuniêta rêka zadaje ciosy znacznie szybciej ni¿ prawa, ale ich si³a jest mniejsza. Nie wykazano istotnych zale¿noœci pomiêdzy si³¹ ciosu a mas¹ cia³a (r=0.220) lub mas¹ cia³a a czasem reakcji (r=0.305). Wiek badanych korelowa³ dodatnio z ca³kowit¹, wzglêdn¹ (N/kg masy cia³a) sum¹ si³ wszystkich uderzeñ (r=0.414 dla p<0.05), lecz nie stwierdzono istnienia takiego zwi¹zku z ³¹cznym czasem reakcji obu r¹k (r=0.198). Znacz¹ce ujemne korelacje (p<0.05) odnotowano pomiêdzy poziomem testosteronu rano a œrednim czasem reakcji w ca³ym teœcie dla rêki wysuniêtej (r=-0.465) i cofniêtej (r=-0.395) oraz pomiêdzy poziomem testosteronu przed testem a czasem reakcji w pierwszej rundzie dla rêki wysuniêtej (r=-0.494) i cofniêtej (r=-0.418). Nie odnotowano zale¿noœci pomiêdzy stê¿eniem testosteronu lub kortyzolu a si³¹ uderzeñ oraz stê¿eniem kortyzolu a czasem reakcji. Wysi³ek nie spowodowa³ wprawdzie istotnego statystycznie wzrostu stê¿enia kortyzolu (o 44 nmol/L w +30 minucie) ani testosteronu (o 1.6 nmol/L w +3 minucie), lecz odnotowane zmiany (o 1.6%) w odniesieniu do znikomego zagêszczenia krwi w 3 minucie po wysi³ku wskazuj¹ na wywo³an¹ wysi³kiem niewielk¹ sekrecjê. Niewielki œredni poziom mleczanu po wysi³ku (4.7 mmol/L) wskazuje na ma³¹ intensywnoœæ pracy. - This copy is for personal use only - distribution prohibited. - This copy is for personal use only - distribution prohibited. - This copy is for personal use only - distribution prohibited. - This copy is for personal use only - distribution prohibited. - Obmiñski Z. et al., Hormone level and psychomotor skills in boxers 15 eo nly -d istr ibu tio np roh ibit ed . During our own study, a noticeable, although statistically insignificant increase in cortisol level (in +30 minute) and a slightly lower increase in testosterone level (in +3 minute) was probably due to secretion, as the effect of hemoconcentration may be ignored. Even a slight stimulation of the adrenal cortex, with such a weak physical stimulus in well trained sportsmen, may be surprising in comparison with a frequently noted lack of cortisol response to maximal effort [32, 33] and post exercise increase in ACTH concentration [34]. In our attempts to explain hormonal changes in the studied boxers, we should consider two simultaneous kinds of stimuli while simulating initial effort of hitting a punching bag (mental and physical). Their stimulating effects might have been additive or even synergistic. There is a wealth of studies indicating that mental effort involving attention may evoke adrenaline [1] or even cortisol [35] secretion, although the pituitary-adrenal axis is not as sensitive to physical stimuli as the adrenergic system [36]. The study conducted by the same authors, on the hormonal response to mental effort repeated twice a day (in the morning and next in the afternoon) may suggest accumulation of mental stress, manifested by a greater increase in salivary cortisol and urinary noradrenaline secretion in the afternoon, as compared to the controls [37], although we cannot exclude that response to stress depends on time of the day. The results have also shown that the tasks requiring simultaneous mental and physical effort, evoke greater fatigue as well as urinary catecholamine (A and NA) and cortisol secretion than any kind of effort alone [38]. It is possible that in our study, stimulation of the adrenal cortex, simultaneous with mental load, was responsible for the observed hormonal changes. The results of other author's studies on mental stress, evoking the increase in cortisol and testosterone concentration after shooting competition, show that hormone secretion is due to psychogenic stimulation [39]. The inversely proportional, statistically significant correlation between testosterone concentration and reaction time is in accordance with the phenomenon observed in young men (students) by other authors [12]. In our study, the correlation between those parameters was not so strong. Probably other studied factors, apart from testosterone level, were involved in this phenomenon. No correlation was noted between cortisol concentration and reaction time. Other authors' reports on poorer mental effort performance in persons with higher cortisol level might suggest a relationship between stress level due to participation in the trial and ability to perform mental tasks. During task performance, perfectionists may be under greater stress, which may result higher cortisolemia [41]. Finally it was proved that the amount of response to a standard stressful stimulus enables differentiation between the subjects with low and high reactivity. Observation of catecholamines does not reveal it to such an extent [42]. In our study, no significant subject to subject differences were noted in cortisol response to a psychometric test, what suggests a relative homogeneity of the studied a cohort of boxers as for responses to stress, despite the differences in age and body mass. It may also suggest that the stimulus (participation in the trial) was not strong enough to reveal such differences. Th is c op y is for pe rs on al us tabolicznej, 421 szybkich uderzeñ wykonanych z maksymaln¹ si³¹ wywo³a³o znacz¹c¹ hemokoncentracjê (3.3%) i wysokie stê¿enie mleczanu (14 mmol/L) [31]. W badaniach w³asnych zauwa¿alny, choæ nieznamienny statystycznie, wzrost stê¿enia kortyzolu (w +30 minucie) i nieco mniejszy testosteronu (w +3 minucie) musia³ byæ spowodowany sekrecj¹, gdy¿ udzia³ hemokoncentracji mo¿na pomin¹æ. Nawet niewielkie pobudzenie kory nadnerczy tak s³abym bodŸcem fizycznym u dobrze wytrenowanych sportowców mo¿e byæ zaskakuj¹ce, w zestawieniu z czêsto notowanym brakiem reakcji kortyzolu na wysi³ki maksymalne [32,33] oraz brakiem takiej reakcji na powysi³kowy wzrost stê¿enia ACTH [34]. W poszukiwaniu wyjaœnienia zmian hormonalnych u badanych bokserów nale¿y wzi¹æ pod uwagê dwa jednoczeœnie typy bodŸców w czasie symulacji wysi³ku startowego na worku (mentalny i fizyczny), których efekty stymuluj¹ce mog³y byæ addytywne lub nawet synergistyczne. Z licznych badañ wynika, ¿e wysi³ek mentalny anga¿uj¹cy uwagê mo¿e wywo³aæ sekrecjê adrenaliny [1], a nawet kortyzolu [35], pomimo ¿e oœ przysadkowo-nadnerczowa nie jest tak wra¿liwa na bodŸce fizyczne jak uk³ad adrenergiczny [36]. Badania tych samych autorów nad hormonaln¹ odpowiedzi¹ na 2-krotnie powtarzany w ci¹gu dnia wysi³ek mentalny (raz przed po³udniem, a potem po po³udniu) mog¹ sugerowaæ kumulacjê stresu mentalnego, co uwidoczni³o siê wiêkszym (w porównaniu do sytuacji kontrolnej) wzrostem poziomu kortyzolu w œlinie i wydalaniem noradrenaliny z moczem po po³udniu [37], chocia¿ nie mo¿na wykluczyæ, ¿e odpowiedŸ na stres zale¿y od pory dnia. Badania wykaza³y równie¿, ¿e zadania wymagaj¹ce jednoczeœnie wysi³ku mentalnego i fizycznego wywo³uj¹ wiêksze ogólne zmêczenie i wydalanie z moczem amin katecholowych (A i NA) oraz kortyzolu ni¿ ka¿dy z osobna rodzaj wysi³ku [38]. W naszych badaniach jednoczesna stymulacja kory nadnerczy wysi³kiem fizycznym i obci¹¿eniem mentalnym mog³a byæ odpowiedzialna za obserwowane zmiany hormonalne. Za udzia³em psychogennego pobudzenia sekrecji hormonów u badanych bokserów przemawiaj¹ tak¿e wyniki badañ innych autorów nad stresem psychologicznym wywo³uj¹cym wzrost stê¿enia kortyzolu i testosteronu po zawodach strzeleckich [39]. Obserwowana w naszych badaniach znamiennie statystyczna, odwrotnie proporcjonalna zale¿noœæ miêdzy stê¿eniem testosteronu a czasem reakcji jest zgodna ze zjawiskiem obserwowanym u m³odych mê¿czyzn (studenci) przez innych autorów [12]. Zwi¹zek korelacyjny miêdzy tymi parametrami w naszych badaniach nie by³ jednak silny. Prawdopodobnie inne badane czynniki, oprócz poziomu testosteronu, mia³y udzia³ w tym zjawisku. Nie odnotowano zale¿noœci miêdzy stê¿eniem kortyzolu a czasem reakcji. Doniesienia autorów o gorszym wykonaniu wysi³ku mentalnego przez osoby z wy¿szym poziomem kortyzolu [40] mog³yby sugerowaæ, ¿e istnieje zwi¹zek pomiêdzy poziomem stresu wywo³anego prób¹ a zdolnoœci¹ do rozwi¹zania zadañ mentalnych. W sytuacjach zadaniowych wiêkszy stres mog¹ wykazywaæ osoby z perfekcyjnym nastawieniem do próby, co mo¿e w konsekwencji spowodowaæ u nich wy¿sz¹ kortyzolemiê [41]. Ostatecznie ujawniono, ¿e wielkoœæ odpowiedzi kortyzolu na standardowy bodziec stresuj¹cy pozwala ró¿nicowaæ badanych na s³abo lub silnie reaktywnych, czego w takim stopniu nie ujawniaj¹ obserwacje amin - This copy is for personal use only - distribution prohibited. - This copy is for personal use only - distribution prohibited. - This copy is for personal use only - distribution prohibited. - This copy is for personal use only - distribution prohibited. - Obmiñski Z. i wsp., Poziom hormonów oraz zdolnoœci psychomotoryczne bokserów 16 eo nly -d istr ibu tio np roh ibit ed . The relation between strength and testosterone level in boxers deserves broader discussion, as no statistical correlations were revealed between those two factors, although they were expected, based on numerous study results, including those obtained in sportsmen and reported in other papers. There has been a long tradition of studying such relationships between maximal strength and/or power and testosterone level in persons of both genders and different age. Analysis of the correlation between age, strength and androgen level in elderly men and women has shown that strength and testosterone level (total and free) decrease with age [43], the lack of correlation however, may suggest that those phenomena are either unrelated or masked by other essential factors. The recommended strength training is told to inhibit this age-related decrease. The expected effect however, has turned out to be limited in elderly people by a very low testosterone level, correlating with posttraining increase of the transverse cross-section of muscular fibres [44]. In the adolescence period, a significant increase in strength and gender – related differences are believed to be due to hormone levels [46} at a certain stage of maturity [45]. Positive linear correlations were noted between testosterone level in young boys (r=+0.64) and girls (r=+0.46) in their stage of adolescence and the total strength. An earlier study however, carried out in physically retarded boys, treated for 3 months with exogenous testosterone, has shown that growth advancement and the increase in lean body mass do not result in strength increase, what may suggest that testosterone itself is not a direct predictor of strength development [47]. Contrary to this, testosterone given to adult males of different age resulted in simultaneous increase in muscular mass and strength [48]. The studies conducted in sportsmen have revealed discipline – related resting testosterone levels and different effect of training on strength and hormonal status. The strength level and blood testosterone concentration were higher in strength and quickness training sportsmen (weightlifting), compared to endurance training sportsmen (road cycling) [49]. These parameter values were also higher in sprinters than in football players and orienteering runners[50]. The analyses of between – subjects correlations however, do not lead to the same conclusions. Most of the studies on strength and blood hormone concentration were carried out in weightlifters, as one may expect that maximal strength level determines results in sport. It has been shown that during competitions, the contestants with higher cortisol level obtained better results and these were top (international) class sportsmen [51]. Resting cortisol and testosterone levels were slightly higher in contestants attaining better results in two hand clean and jerk and two hand snatch [52]. Long lasting training disturbs the relation between strength and testosterone. During the first 20 weeks of the training period, blood free testosterone level gradually decreased, while maximal isometric force paradoxically increased. During next 4 weeks, both testosterone fractions, free and total, increased with the force and the relative changes in both variables significantly correlated (r=0..60) [53]. Some authors observed a gradual decrease in maximal force and increase in testosterone level on finishing the train- Th is c op y is for pe rs on al us katecholowych [42]. W naszych badaniach nie zauwa¿ono du¿ego miêdzyosobniczego zró¿nicowania odpowiedzi kortyzolu na test psychometryczny, co sugeruje, ¿e badana grupa bokserów, pomimo ró¿nic w wieku i masie cia³a, jest doœæ homogeniczna w odniesieniu do sposobu reagowania na stres lub te¿, ¿e ta próba nie by³a wystarczaj¹co silnym bodŸcem, by takie ró¿nice ujawniæ. U bokserów relacje si³a-testosteron zas³uguj¹ na wnikliwe omówienie, gdy¿ nie wykryto ¿adnych statystycznych zale¿noœci, a spodziewano siê takich na podstawie licznych cytowanych w literaturze wyników badañ u innych osób, w tym sportowców. Badanie takich zwi¹zków miêdzy si³¹ i/lub moc¹ maksymaln¹ a poziomem testosteronu u obu p³ci w ró¿nym wieku ma wieloletni¹ tradycjê. Analiza zale¿noœci wiek-si³a-androgeny u starszych mê¿czyzn i kobiet wskaza³a, ¿e z wiekiem spada si³a i równolegle poziom testosteronu (ca³kowitego i wolnego) [43], ale brak korelacji mo¿e sugerowaæ, ¿e s¹ to zjawiska albo niezale¿ne, albo wiele innych, istotnych czynników maskuje oczekiwan¹ zale¿noœæ. Zalecane treningi si³y u tych osób maj¹ hamowaæ tempo jej utraty wraz z wiekiem. Okazuje siê jednak, ¿e oczekiwane efekty tych treningów u starszych osób s¹ ograniczone bardzo niskim poziomem testosteronu, który korelowa³ z potreningowym wzrostem przekroju poprzecznego w³ókien miêœniowych [44]. Z kolei u dojrzewaj¹cej m³odzie¿y, która nie trenuje, istotny wzrost si³y i jej zale¿ne od p³ci zró¿nicowanie po osi¹gniêciu pewnego etapu dojrza³oœci [45] przypisuje siê hormonom [46]. U dojrzewaj¹cej m³odzie¿y stwierdzono dodatnie korelacje liniowe pomiêdzy poziomem testosteronu we krwi u ch³opców (r=+0.64) i dziewcz¹t (r=+0.46) a ca³kowit¹ si³¹. Jednak wczeœniejsze badania ch³opców z opóŸnionym rozwojem fizycznym (leczonych przez 3 miesi¹ce egzogennym testosteronem) wykaza³y, ¿e przyspieszenie wzrostu i zwiêkszenie bezt³uszczowej masy cia³a nie poci¹ga³o za sob¹ wzrostu si³y [47], co mo¿e sugerowaæ, ¿e u m³odzie¿y sam poziom testosteronu nie jest bezpoœrednim predyktorem rozwoju si³y. W przeciwieñstwie do tego, podawanie testosteronu doros³ym mê¿czyznom w ró¿nym wieku, starszym i m³odszym, spowodowa³o równoleg³y wzrost masy miêœni i ich si³y [48]. Badania sportowców ujawni³y, zale¿ne od typu dyscypliny, spoczynkowe stê¿enia testosteronu oraz ró¿noraki wp³yw treningów na si³ê i status hormonalny. Poziom si³y i stê¿enie testosteronu we krwi u sportowców dyscyplin si³owo-szybkoœciowych (podnoszenie ciê¿arów) by³y wy¿sze ni¿ u sportowców trenuj¹cych wytrzyma³oœæ (kolarstwo szosowe) [49], a u sprinterów wy¿szy ni¿ u pi³karzy lub biegaczy na orientacjê [50]. Jednak analizy zale¿noœci wewn¹trz grup nie zawsze prowadz¹ do tych samych wniosków. Wiêkszoœæ badañ nad si³¹ i zachowaniem hormonów we krwi prowadzono u zawodników podnosz¹cych ciê¿ary, gdy¿ mo¿na oczekiwaæ, ¿e w tym sporcie poziom maksymalnej si³y determinuje wynik sportowy. Wykazano, ¿e w czasie oficjalnych zawodów lepsze wyniki uzyskali zawodnicy, u których poziom kortyzolu by³ wy¿szy i byli to sportowcy wy¿szej klasy sportowej (miêdzynarodowej) [51]. Spoczynkowe poziomy kortyzolu i testosteronu by³y nieco wy¿sze u zawodników osi¹gaj¹cych lepsze wyniki w rwaniu i podrzucie [52]. D³ugotrwa³y trening si³y zaburza relacjê si³a-testosteron. W trakcie pierwszych 20 tygodni okresu treningowego po- - This copy is for personal use only - distribution prohibited. - This copy is for personal use only - distribution prohibited. - This copy is for personal use only - distribution prohibited. - This copy is for personal use only - distribution prohibited. - Obmiñski Z. et al., Hormone level and psychomotor skills in boxers 17 ing. This is a manifestation of gradual decrease in the previously acquired neural adaptation, thought to be the main factor responsible for maximal force [54]. In our study no expected correlations have been found between blow force and testosterone concentration. This may result from the fact that the sportsmen did not try to develop maximal power and force of blows. They developed blow force which allowed them to obtain good results of reaction time. The possible reason for this is that there seems to be little chance to develop maximal force and speed simultaneously, and that short reaction time was the contestants' priority. This hypothesis is supported by a surprising lack of correlation between blow force and the subject's body mass, despite the broad range of this variable (48-91 kg). Assuming that the recorded mean individual blow force does not fully reflect the contestant's real potential, it is hard to expect any correlation between this variable and testosterone level. Wnioski Conclusions tio np roh ibit ibu -d istr nly eo 1. Mean values of the measured psychomotor parameters are characterized by high stability during subsequent rounds and the effect of fatigue is not noticeable. 2. Different techniques of striking blows with the left or right hand determines the differences in reaction time and force of blows for both extremities. 3. There is a relation between blood testosterone level in boxers and reaction time during exercise, specific for this sport. on al us 1. Œrednie wartoœci mierzonych parametrów psychomotorycznych wykazuj¹ du¿¹ stabilnoœæ w kolejnych rundach i nie widaæ efektu zmêczenia pod koniec próby. 2. Ró¿na technika zadawania ciosów lew¹ lub praw¹ rêk¹ determinuje ró¿nice w czasach reakcji i sile uderzeñ dla obu koñczyn. 3. Istnieje zwi¹zek pomiêdzy poziomem testosteronu we krwi u bokserów a czasem reakcji w trakcie wykonywania specyficznego dla tego sportu wysi³ku. ed . ziom wolnej frakcji hormonu we krwi stopniowo mala³, podczas gdy, paradoksalnie, maksymalna izometryczna si³a ros³a. Natomiast w nastêpnych 4 tygodniach obie frakcje testosteronu, wolna i ca³kowita, ros³y wraz z si³¹, a wzglêdne zmiany obu zmiennych znacz¹co ze sob¹ korelowa³y (r=0.. 60) [53]. Niektórzy autorzy, po zakoñczeniu cyklu treningowego si³y, obserwowali stopniowy spadek si³y maksymalnej i wzrost testosteronu. Takie zjawisko dowodzi stopniowej utraty nabytej wczeœniej adaptacji neuralnej, która uwa¿ana jest za g³ówny czynnik odpowiedzialny za si³ê maksymaln¹ [54]. W naszych badaniach brak spodziewanych zale¿noœci pomiêdzy si³¹ uderzeñ a testosteronem mo¿e wynikaæ st¹d, ¿e sportowcy nie próbowali rozwin¹æ maksymalnej mocy i si³y uderzenia, lecz jedynie tak¹, która gwarantowa³a uzyskanie dobrych wyników czasu reakcji. Mo¿e to wynikaæ st¹d, ¿e jednoczesne uzyskanie maksymalnej si³y i szybkoœci wydaje siê ma³o prawdopodobne i w teœcie laboratoryjnym krótki czas reakcji by³ dla badanych priorytetem. Za tak¹ hipotez¹ przemawia zaskakuj¹cy w naszych obserwacjach brak korelacji pomiêdzy si³¹ ciosu a mas¹ badanego, pomimo szerokiego przedzia³u tej zmiennej (48-91 kg). Przyjmuj¹c wiêc, ¿e rejestrowana w teœcie œrednia osobnicza si³a ciosu nie w pe³ni odzwierciedla rzeczywiste mo¿liwoœci zawodnika, trudno oczekiwaæ zwi¹zku pomiêdzy t¹ zmienn¹ a stê¿eniem testosteronu. pe rs Piœmiennictwo / References Th is c op y is for 1. Sothmann MS, Hart BA, Horn TS. Selected psycho-physiological stress responses in men with high and low body fatness. Med Sci Sports Exerc 1995; 27: 417-422. 2. Sothmann MS, Hart BA, Horn TS. Plasma catecholamine responses to acute psychological stress in humans: Relation to aerobic fitness and exercise training. Med Sci Sports Exerc 1991; 23: 860-867. 3. Fischer LV, Andreassi JL. Stress and personality as factors in women`s cardiovascular reactivity. Int J Psychophysiol 1998; 28: 143-155. 4. Jones KV, Kopolov DL, Outh. KH. Type A, test performance and salivary cortisol. J Psychosom Res 1986; 30: 699707. 5. Bell DG, Jakobs I. Electromechanical response time and rate of force development in males and females. 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