The aim of the current study was to investigate the hormonal, physiological, and physical responses of simulated kickboxing competition and evaluate if there was a difference between winners and losers. Twenty athletes of regional and national level participated in the study (mean ± SD age 21.3 ± 2.7 y, height 170.0 ± 5.0 cm). Hormone (cortisol, testosterone, growth hormone), blood lactate [La], and glucose concentrations, as well as upper-body Wingate test and countermovement-jump (CMJ) performances, were measured before and after combats. Heart rate (HR) was measured throughout rounds 1, 2, and 3 and rating of perceived exertion (RPE) was taken after each round. All combats were recorded and analyzed to determine the length of different activity phases (high-intensity, low-intensity, and referee pause) and the frequency of techniques. Hormones, glucose, [La], HR, and RPE increased (all P < .001) precombat to postcombat, while a decrease was observed for CMJ, Wingate test performance, body mass (all P < .001), and time of high-intensity activities (P = .005). There was no difference between winners and losers for hormonal, physiological, and physical variables (P > .05). However, winners executed more jab cross, total punches, roundhouse kicks, total kicks, and total attacking techniques (all P < .042) than losers. Kickboxing is an intermittent physically demanding sport that induces changes in the stress-related hormones soliciting the anaerobic lactic system. Training should be oriented to enhance kickboxers’ anaerobic lactic fitness and their ability to strike at a sufficient rate. Further investigation is needed to identify possible differences in tactical and mental abilities that offer some insight into what makes winners winners.
Ibrahim Ouergui, Philip Davis, Nizar Houcine, Hamza Marzouki, Monia Zaouali, Emerson Franchini, Nabil Gmada and Ezzedine Bouhlel
Ida A. Heikura, Marc Quod, Nicki Strobel, Roger Palfreeman, Rita Civil and Louise M. Burke
-day racing. Our aim was to (1) assess energy and carbohydrate availability and changes in blood hormones as a consequence of changes in EA in professional male cyclists over 4 separate single-day races within an 8-day period and (2) to investigate the robustness of our methodology to collect data in a
Bruno P. Melo, Débora A. Guariglia, Rafael E. Pedro, Dennis A. Bertolini, Solange de Paula Ramos, Sidney B. Peres and Solange M. Franzói de Moraes
mellitus, or obesity. 14 – 16 However, as there was no increase in cortisol after combined exercise in the present study, it is possible to suggest that the 3 sets of 15 maximum repetitions used in this study can be considered safe for ILWHA. Testosterone is a hormone associated with several anabolic
Alan D. Rogol
Most hormonal agents used for nonmedical purposes in athletes have legitimate medical uses. This review introduces each compound by its pharmacology, clinical pharmacology, and legitimate medical use and reviews information on its abuse. Human growth hormone is presently available in virtually unlimited quantities due to its production by recombinant DNA technology. Its use in athletes is considered for its muscle-building, fat-depleting properties. Erythropoietin is a kidney hormone that increases red cell mass. It is used for renal dialysis patients to avoid blood transfusions. Its use in athletes is to raise red blood cell mass in an attempt to augment maximal oxygen capacity and the ability to do endurance work. Human chorionic gonadotropin has the biological activity of luteinizing hormone to increase testosterone synthesis and to maintain (partially) testicular volume when exogenous androgens are taken. Clenbuterol is a beta2 adrenergic agonist with muscle-building properties that are seemingly specific to striated muscle; clenbuterol may cause reduction in body fat.
Dietrich Rothenbacher, Dhayana Dallmeier, Michael D. Denkinger, Bernhard O. Boehm, Wolfgang Koenig, Jochen Klenk and ActiFE Study Group
Sex hormone-binding globulin (SHBG) is the blood transport protein for testosterone and other steroids. Low SHBG serum levels are associated with many adverse health effects in older adults, including metabolic syndrome, diabetes, endothelial function, specific cancers, and low bone mineral density
Marquis Hawkins, Deirdre K. Tobias, Hala B. Alessa, Andrea K. Chomistek, Junaidah B. Barnett, Walter C. Willett and Susan E. Hankinson
Physical activity (PA) has been associated with a reduced risk of developing breast cancer. Indeed, physical inactivity has been attributed to an estimated 10% of breast cancer cases worldwide. 1 The relationship between PA and breast cancer risk may be mediated through its effects on sex hormones
Valerie J. Wirth and Joe Gieck
Growth hormone is one of the many dangerous and illegal ergogenic aids currently used by athletes. In those who suffer from a growth hormone deficiency, supplementation does produce positive results: Muscle volume increases while adipose tissue volume is significantly reduced. Growth hormone supplementation can also lead to strength increases in the deficient population (2, 6, 13) as well as in the elderly population (16, 18, 25). In healthy young men, growth hormone supplementation has been shown to increase fat-free mass and to decrease fat mass. However, these changes are not accompanied by strength gains (5, 7, 23, 24). This finding, coupled with the numerous side effects associated with the drug, presents a strong case for athletes to abandon its use as an ergogenic aid.
Paola Rodriguez-Giustiniani and Stuart D.R. Galloway
as drink composition and volume ( Shirreffs & Maughan, 2000 ), but it is also believed that hormonal changes associated with the menstrual cycle can influence fluid retention ( Fortney, 1996 ). Although fluid replacement after dehydration has been extensively studied in males, there have been few
Linn Bøhler, Sílvia Ribeiro Coutinho, Jens F. Rehfeld, Linda Morgan and Catia Martins
the improvement in meal-related satiety seen after an exercise intervention may result from changes in postprandial satiety signaling, specifically the postprandial plasma concentrations of appetite-related hormones. Even though the precise reasons for the more sensitive eating behavior in response to
Ioanna Athanasiadou, Sven Christian Voss, Wesal El Saftawy, Hind Al-Jaber, Najib Dbes, Sameera Al-Yazedi, Waseem Samsam, Vidya Mohamed-Ali, Mohammed Alsayrafi, Georgia Valsami and Costas Georgakopoulos
Luteinizing hormone (LH) is a glycoprotein with an approximate molecular weight of 28.5 kDa. It is physiologically produced and secreted by the gonadotropic cells in the anterior pituitary gland. This heterodimer protein is composed of two polypeptide chains, alpha and beta. Nonetheless, only the