Trainingsphysiologische Faktoren der Gewichtsreduktion im Sport

Publication: Book/ReportDissertations


Introduction: Taekwondo (TKD), judo, wrestling and boxing are the Olympic combat sports in which different weight categories are applied. The goal of weight categories is to ensure the athletes a fair and interesting combat. In Taekwondo, Judo and wrestling, the weigh-in takes place in the afternoon prior to the competition day. Several practices of weight reduction are used for the weigh-in. In order to compete against smaller and weaker opponents in the next lighter weight class, rapid weight reduction (RWR) is often favored by combat athletes. The outcomes of previous studies, because of the study protocol, are not comparable or consistent. In previous studies, gradual weight reduction (longer than four weeks) was rarely conducted in TKD athletes. The aim of the present dissertation was to conduct the sport-specific measurements regarding rapid and gradual weight reduction (GWR). Consequently, the effects of physiological, hemorheological, and psychological changes and athletic performance could be compared and determined.
Methods: In order to determine a better method of body weight reduction between RWR and GWR prior to the competition physiological, psychological, and hemorheological parameters in TKD athletes were analyzed and separated into two studies. RWR by 5% of body weight was performed for four days, while GWR by 5% was conducted for four weeks. A one week break was scheduled between both interventions. A measurement after both weight reductions was generated and took place on the official competition day. Subsequently, a review study of several scientific factors regarding RWR were performed.
Results: The body water during RWR compared to GWR was decreased. Furthermore, physiological parameters such as glucose, creatine kinase, creatinine, urea and electrolytes were also decreased. Scale values of the mood state were clearly more impaired in RWR phase than in GWR phase. The TKD-kickfrequency during RWR compared to GWR was decreased. During RWR, deformability and aggregation of red blood cells (RBC) were negatively affected, which were predominantly caused by the decreased activation of nitric oxide synthase (RBC-NOS). During review study, negative effects of several physiological indicators, such as stress hormones, oxidative stresses, plasminogen-activator-inhibitor-1 (PAI-1) and recovery period of RWR between weigh-in and competition day, were considered.
Discussion/Conclusion: The results of our studies lead to information of physiological, psychological, and hemorheological impairments of four day RWR compared to four week
GWR. Also, several studies indicated negative effects of RWR on the physiological factors prior to the official competition. The impaired indicators can decrease athletic performances. The time between weigh-in and competition day after RWR may play a key role for the successful competition of athletes, but this was rarely considered in previous studies. In order to avoid a decrease of the performance athletes, trainers should schedule a weight reduction at least four weeks prior to competition. Athletes should avoid high intensity exercise sessions in the morning during RWR phase because of the impaired physiological responses. Indeed, International, National, and Regional federations of Olympic combat sports should control weight cutting.
Original languageGerman
Place of PublicationKöln
PublisherDeutsche Sporthochschule Köln
Number of pages43
Publication statusPublished - 2017