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Biological Rhythm Research

2013

Effects of partial sleep deprivation at the end of the night on anaerobic performances in judokas  (  Article in press  )

HajSalem, M.^a , Chtourou, H.^b, Aloui, A.^b, Hammouda, O.^b, Souissi, N.^bc  

^a  Research Unit (EM2S), High Institute of Sport and Physical Education, Sfax University, Sfax, Tunisia
^b  Research Laboratory Sport Performance Optimization, National Centre of Medicine and Sciences in Sport (CNMSS), Tunis, Tunisia
^c  High Institute of Sport and Physical Education, Ksar-Saïd, Manouba University, Tunis, Tunisia

Abstract

The aim of the present study was to examine the effect of partial sleep deprivation at the end of the night (PSDE) on anaerobic performances during the Wingate test (peak (PP) and mean (MP) power) and the hand grip (HG) test in judokas. In a randomized order, twenty-one judokas (age: 19.1 ± 1.2 yrs; height: 176.5 ± 4.2 cm; body mass: 77.3 ± 6.3 kg) performed two sessions after a normal sleep night (NSN) or a PSDE. During each session, they carried out the Wingate and the HG tests before (T0) and after (T1) a judo match. Rating of perceived exertion (RPE) scores were obtained at the end of the combat. PP and MP decreased significantly from T0 to T1 during the two experimental conditions (p < 0.01), and from NSN to PSDE at T0 and T1 (p < 0.05). However, the HG strength decreased only from T0 to T1 (p < 0.001) and was not significantly affected by PSDE. Likewise, the RPE scores were not affected by PSDE. Therefore, PSDE (i) reduced muscle power during the Wingate test and (ii) did not affect muscle strength during the HG test.

Suplementação de glutamina em atletas de judô

Luminescence

2013

Effect of glutamine supplementation on neutrophil function in male judoists  (  Article in press  )

Sasaki, E.^a , Umeda, T.^a, Takahashi, I.^a, Arata, K.^b, Yamamoto, Y.^b, Tanabe, M.^ab, Oyamada, K.^a, Hashizume, E.^c, Nakaji, S.^a  

^a  Department of Social Medicine Hirosaki University Graduate School of Medicine Hirosaki, Aomori Japan
^b  Department of Physical Education Nippon Sport Science University Setagaya Tokyo Japan
^c  Healthcare Products Development Center Kyowa Hakko Bio Co., Ltd. Tsukuba Japan

Abstract

Glutamine is an important amino acid for immune function. Though high intensity and prolonged exercise decreases plasma glutamine concentration and causes immune suppression, the relationship between neutrophil functions and glutamine has not yet been found. The purpose of this study was to investigate the impacts of glutamine supplementation on neutrophil function. Twenty-six male university judoists were recruited. Subjects were classified into glutamine and control groups. The glutamine group ingested 3000 mg of glutamine per day and the control group ingested placebo for 2 weeks. Examinations were performed at the start of preunified loading exercise (pre-ULE), then 1 and 2 weeks after ULE (post-ULE). Reactive oxygen species (ROS) production, phagocytic activity, serum opsonic activity and serum myogenic enzymes were measured. Differences between the levels obtained in pre-ULE and post-ULE for the two groups were compared. In the glutamine group, ROS production activity increased 1 week after ULE, whereas it was not observed in the control group (P<0 .001="" activity="" after="" an="" and="" by="" damage="" during="" enzymes="" especially="" even="" excessive="" function="" glutamine="" group="" has="" in="" increased="" intensive="" muscle="" myogenic="" nbsp="" neutrophil="" of="" p="" period.="" prevented="" production="" remained="" ros="" significantly="" supplementation="" suppression="" the="" though="" training="" ule.="" ule="" unchanged="">

Arbitragem no judô

European Journal of Sport Science

2013

Judges in judo conform to the referee because of the reactive feedback system  (  Article in press  )

Boen, F.^a , Ginis, P.^b, Smits, T.^c  

^a  Department of Kinesiology, KU Leuven, Tervuursevest 101, Heverlee, Leuven 3001, Belgium
^b  Department of Rehabilitation Sciences, KU Leuven, Leuven, Belgium
^c  Institute for Media Studies, KU Leuven, Leuven, Belgium

Abstract

This experiment tested whether the conformism observed among panels of judges in aesthetic sports also occurs among judges in judo. Similar to aesthetic sports, judo judging relies upon a form of open feedback. However, in judo, this system is reactive (i.e. two judges have to publicly 'correct' the score given by the higher-status referee), whereas it is active in aesthetic sports (i.e. judges with equal status report their score simultaneously and can use the feedback about the scores of their colleagues for evaluating later performances). In order to test whether such reactive open-feedback system leads to conformism among judges in judo, we designed an experiment in which this feedback was manipulated. Participants were 20 certified Flemish judges, who had to score two sets of 11 ambiguous video sequences that are used during formation and training of judo judges: one set with feedback about the referee's score and one set without feedback. The results revealed that when participants knew the referee's score, their scores were significantly more in line with this score than when they did not know this score. More specifically, for both sets of sequences at least 10% less deviations from the referee were observed when participants were given feedback about the score of the referee. These results suggest that preventable conformism can occur in typical judo judging, that is with reactive open feedback.