Jonatas Ferreira da Silva Santos

Physical and Physiological Profiles of Taekwondo Athletes

Taekwondo has evolved into a modern-day Olympic combat sport. The physical and physiological demands of modern-day taekwondo competition require athletes to be competent in several aspects of fitness. This review critically explores the physical and physiological characteristics of taekwondo athletes and presents implications for training and research. International taekwondo athletes possess low levels of body fat and a somatotype that characterises a blend of moderate musculoskeletal tissue and relative body linearity. While there is some variation in the maximum oxygen uptake of taekwondo athletes, moderate to high levels of cardio-respiratory fitness are necessary to support the metabolic demands of fighting and to facilitate recovery between consecutive matches. Taekwondo athletes demonstrate high peak anaerobic power characteristics of the lower limbs and this attribute appears to be conducive to achieving success in international competition. The ability to generate and sustain power output using both concentric and ‘stretch-shortening cycle’ muscle actions of the lower limbs may be important to support the technical and tactical actions in combat. Taekwondo competitors also display moderate to high maximum dynamic strength characteristics of the lower and upper extremities, and moderate endurance properties of the trunk and hip flexor musculature. The dynamic nature of the technical and tactical actions in the sport demand high flexibility of the lower limbs. More extensive research is required into the physical and physiological characteristics of taekwondo athletes to extend existing knowledge and to permit specialised conditioning for different populations within the sport.

Caffeine Ingestion Increases Estimated Glycolytic Metabolism during Taekwondo Combat Simulation but Does Not Improve Performance or Parasympathetic Reactivation

Objectives The aim of this study was to evaluate the effect of caffeine ingestion on performance and estimated energy system contribution during simulated taekwondo combat and on post-exercise parasympathetic reactivation. Methods Ten taekwondo athletes completed two experimental sessions separated by at least 48 hours. Athletes consumed a capsule containing either caffeine (5 mg∙kg-1) or placebo (cellulose) one hour before the combat simulation (3 rounds of 2 min separated by 1 min passive recovery), in a double-blind, randomized, repeated-measures crossover design. All simulated combat was filmed to quantify the time spent fighting in each round. Lactate concentration and rating of perceived exertion were measured before and after each round, while heart rate (HR) and the estimated contribution of the oxidative (WAER), ATP-PCr (WPCR), and glycolytic (W[La-]) systems were calculated during the combat simulation. Furthermore, parasympathetic reactivation after the combat simulation was evaluated through 1) taking absolute difference between the final HR observed at the end of third round and the HR recorded 60-s after (HRR60s), 2) taking the time constant of HR decay obtained by fitting the 6-min post-exercise HRR into a first-order exponential decay curve (HRRτ), or by 3) analyzing the first 30-s via logarithmic regression analysis (T30). Results Caffeine ingestion increased estimated glycolytic energy contribution in relation to placebo (12.5 ± 1.7 kJ and 8.9 ± 1.2 kJ, P = 0.04). However, caffeine did not improve performance as measured by attack number (CAF: 26. 7 ± 1.9; PLA: 27.3 ± 2.1, P = 0.48) or attack time (CAF: 33.8 ± 1.9 s; PLA: 36.6 ± 4.5 s, P = 0.58). Similarly, RPE (CAF: 11.7 ± 0.4 a.u.; PLA: 11.5 ± 0.3 a.u., P = 0.62), HR (CAF: 170 ± 3.5 bpm; PLA: 174.2 bpm, P = 0.12), oxidative (CAF: 109.3 ± 4.5 kJ; PLA: 107.9 kJ, P = 0.61) and ATP-PCr energy contributions (CAF: 45.3 ± 3.4 kJ; PLA: 46.8 ± 3.6 kJ, P = 0.72) during the combat simulation were unaffected. Furthermore, T30 (CAF: 869.1 ± 323.2 s; PLA: 735.5 ± 232.2 s, P = 0.58), HRR60s (CAF: 34 ± 8 bpm; PLA: 38 ± 9 bpm, P = 0.44), HRRτ (CAF: 182.9 ± 40.5 s, PLA: 160.3 ± 62.2 s, P = 0.23) and HRRamp (CAF: 70.2 ± 17.4 bpm; PLA: 79.2 ± 17.4 bpm, P = 0.16) were not affected by caffeine ingestion. Conclusions Caffeine ingestion increased the estimated glycolytic contribution during taekwondo combat simulation, but this did not result in any changes in performance, perceived exertion or parasympathetic reactivation.

Can different conditioning activities and rest intervals affect the acute performance of taekwondo turning kick

Abstract da Silva Santos, JF, Valenzuela, TH, and Franchini, E. Can different conditioning activities and rest intervals affect the acute performance of taekwondo turning kick? J Strength Cond Res 29(6): 1640–1647, 2015—This study compared the acute effect of strength, plyometric, and complex exercises (combined strength and plyometric exercise) in the countermovement jump (CMJ) and frequency speed of kick test (FSKT) and attempted to establish the best rest interval to maximize performance in the CMJ, number of kicks, and impact generated during FSKT. Eleven taekwondo athletes (mean ± SD; age: 20.3 ± 5.2 years; body mass: 71.8 ± 15.3 kg; height: 177 ± 7.2 cm) participated. One control and 9 experimental conditions were randomly applied. Each condition was composed of warm-up, conditioning activity (half-squat: 3 × 1 at 95% 1RM; jumps: 3 × 10 vertical jumps above 40-cm barrier; or complex exercise: half-squat 3 × 2 at 95% 1RM + 4 vertical jumps above 40-cm barrier), followed by different rest intervals (5-, 10-minute, and self-selected) before CMJ and FSKT. The conditions were compared using an analysis of variance with repeated measures, followed by Bonferronis post hoc test. The alpha level was set at 5%. Significant difference was found in the number of kicks (F 9,90 = 1.32; p = 0.239; and &eegr;2 = 0.116 [small]). The complex method with a 10-minute rest interval (23 ± 5 repetitions) was superior (p = 0.026) to the control (19 ± 3 repetitions), maximum strength with a self-selected rest interval (328 ± 139 seconds; 18 ± 2 repetitions) (p = 0.015), and plyometric with a 5-minute rest interval (18 ± 3 repetitions) (p < 0.001). Our results indicate that taekwondo athletes increased the number of kicks in a specific test by using the complex method when 10-minute rest interval was used.

The Effects of Hyperbaric Oxygen Therapy on Post-Training Recovery in Jiu-Jitsu Athletes

Objectives The present study aimed to evaluate the effects of using hyperbaric oxygen therapy during post-training recovery in jiu-jitsu athletes. Methods Eleven experienced Brazilian jiu-jitsu athletes were investigated during and following two training sessions of 1h30min. Using a cross-over design, the athletes were randomly assigned to passive recovery for 2 hours or to hyperbaric oxygen therapy (OHB) for the same duration. After a 7-day period, the interventions were reversed. Before, immediately after, post 2 hours and post 24 hours, blood samples were collected to examine hormone concentrations (cortisol and total testosterone) and cellular damage markers [creatine kinase (CK), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH)]. Moreover, the rating of perceived exertion (RPE) and recovery (RPR) scales were applied. Results Final lactate [La] values (control: 11.9 ± 1.4 mmol/L, OHB: 10.2 ± 1.4 mmol/L) and RPE [control: 14 (13–17 a.u.), OHB: 18 (17–20 a.u.)] were not significantly different following the training sessions. Furthermore, there was no difference between any time points for blood lactate and RPE in the two experimental conditions (P>0.05). There was no effect of experimental conditions on cortisol (F1,20 = 0.1, P = 0.793, η2 = 0.00, small), total testosterone (F1,20 = 0.03, P = 0.877, η2 = 0.00, small), CK (F1,20 = 0.1, P = 0.759, η2 = 0.01, small), AST (F1,20 = 0.1, P = 0.761, η2 = 0.01, small), ALT (F1,20 = 0.0, P = 0.845, η2 = 0.00, small) or LDH (F1,20 = 0.7, P = 0.413, η2 = 0.03, small). However, there was a difference between the two experimental conditions in RPR with higher values at post 2 h and 24 h in OHB when compared to the control condition (P<0.05). Conclusions Thus, it can be concluded that OHB exerts no influence on the recovery of hormonal status or cellular damage markers. Nonetheless, greater perceived recovery, potentially due to the placebo effect, was evident following the OHB condition.

Sodium bicarbonate ingestion increases glycolytic contribution and improves performance during simulated taekwondo combat

Abstract Purpose: To investigate the effect of sodium bicarbonate (NaHCO3) on performance and estimated energy system contribution during simulated taekwondo combat. Methods: Nine taekwondo athletes completed two experimental sessions separated by at least 48 h. Athletes consumed 300 mg/kg body mass of NaHCO3 or placebo (CaCO3) 90 min before the combat simulation (three rounds of 2 min separated by 1 min passive recovery), in a double-blind, randomized, repeated-measures crossover design. All simulated combat was filmed to quantify the time spent fighting in each round. Lactate concentration [La−] and rating of perceived exertion (RPE) were measured before and after each round, whereas heart rate (HR) and the estimated contribution of the oxidative (WOXI), ATP (adenosine triphosphate)-phosphocreatine (PCr) (WPCR), and glycolytic (W[ La− ]) systems were calculated during the combat simulation. Results: [La−] increased significantly after NaHCO3 ingestion, when compared with the placebo condition (+14%, P = 0.04, d = 3.70). NaHCO3 ingestion resulted in greater estimated glycolytic energy contribution in the first round when compared with the placebo condition (+31%, P = 0.01, d = 3.48). Total attack time was significantly greater after NaHCO3 when compared with placebo (+13%, P = 0.05, d = 1.15). WOXI, WPCR, VO2, HR and RPE were not different between conditions (P > 0.05). Conclusion: NaHCO3 ingestion was able to increase the contribution of glycolytic metabolism and, therefore, improve performance during simulated taekwondo combat.

Normative tables for the dynamic and isometric judogi chin-up tests for judo athletes

BackgroundNo study has elaborated the normative tables to classify judo athletes as to the dynamic and isometric chin-up judogi tests.PurposeTo elaborate normative judogi chin-up tables to classify judo athletes.Methods138 male judo athletes from state, national, and international levels participated in the study. All tests were carried out during the competitive period. The tests can be performed by absolute values or relativized by body mass.ResultsData were distributed as percentile, with absolute values ≤ 10% (very poor ≤ 10 s; ≤ 1 rep), 11 a 25% (poor 11–25 s; 2–6 reps), 26–75% (regular 26–55 s; 7–16 reps), 76–90% (good 56–62 s; 17–19 reps), and > 90% (excellent ≥ 63 s; ≥ 20 reps). The relativized values consist of the following classifications [body mass multiplied per seconds (s) or repetitions (reps)] ≤ 10% (very poor ≤ 1051 kg.s; ≤ 121 kg.rep), 11–25% (poor 1052–2041 kg.s; 122–474 kg.rep), 26–75% (regular 2042–3962 kg.s; 475–1190 kg.rep), 76–90% (good 3963–4008 kg.s; 1191–1463 kg.rep), and > 90% (excellent ≥ 4009 kg.s; ≥ 1464 kg.rep).ConclusionThe normative table can be used as a reference to classify judo athletes as to specific used as a reference to classify judo athletes as to specific dynamic and isometric endurance strength holding the judogi, a specific field test which is low cost and can be implemented with the basic equipment.

Weight loss in mixed martial arts athletes

The mixed martial arts (MMA) is among the sports with higher spectators increase in the world. This fact can be observed in growth of exposure on media and increased num ber of practitioners and spectators [1]. This sport is composed by combination of boxing, Muay Thai, karate, taekwondo, wrestling, Brazilian jiu-jitsu, judo and other disciplines specific techniques. Nowadays, the MMA is practiced in various countries being the sixth more popular sport in United States of America [2]. Despite the notoriety achieved, few studies aimed to investigate the different fields of this sport. Among the studies that have been conducted involving MMA, most focused on the injuries happened during combat [2-5]. In many sports, especially in combat sports, the athletes are divided according to body mass. This strategy is adopted to leave the disputes more balanced. However, it is commonly observed that athletes conduct some arrangements to reduce large amounts of body mass to move to lighter categories, in an attempt to compete against smaller and weaker opponents [6]. In fact, there are data indicating that boxers [7,8], judokas [9,10], wrestlers [11], Brazilian jiu-jitsu athletes [9-12], taekwondo athletes [13,14] and karate athletes [9] adopt methods to reduce the body mass prior to a competition, but no study has been conducted involving the MMA. This practice can be harmful, because it negatively alters the humor profile, sports performance and health, especially when the magnitude of reduced mass is high [6,15]. It is not difficult to find reports of combat sports athletes reducing a large percentage of body mass. For example, in university level Olympic wrestling (n = 63), 89% of the athletes reported to be engaged in some procedure to reduce body mass prior

Weight loss practices in Taekwondo athletes of different competitive levels

This study investigated the prevalence, magnitude, and methods of rap-id weight loss among male and female Taekwondo athletes from all competitive levels. A questionnaire was administered to 72 men (regional/state level, n=31; national/international level, n=41) and 44 women (regional/state level, n=9; national/international, n=35). Among the male athletes, 77.4% of the regional/state level and 75.6% of the national/international athletes declared to have reduced weight to compete in lighter weight categories. Among women, 88.9% of regional/state level and 88.6% of national/international level reported the use of rapid weight loss strategies. Athletes reported to usually lose ~3% of their body weight, with some athletes reaching ~7% of their body weight. The methods used to achieve weight loss are potentially dangerous to health and no difference between sexes was found. Four methods were more frequently used by men athletes in higher competitive levels as compared to lower levels, as follows: skipping meals (Z=2.28, P=0.023, η2=0.21), fasting (Z=2.337, P=0.019, η2=0.22), restricting fluids (Z=2.633, P=0.009, η2=0.24) and spitting (Z=2.363, P=0.018, η2=0.22). Taekwondo athletes lost ~3% of their body mass, using methods potentially dangerous for their health. Although no difference was found between sexes, lower level athletes more frequently used methods such as skipping meals, fasting, restricting fluids and spitting. Considering that these health-threating methods are more commonly used by lower level athletes, specific education programs should be directed to them.

Can caffeine supplementation reverse the effect of time of day on repeated sprint exercise performance

The aim of this study was to evaluate if caffeine can reduce the negative influence of diurnal variations on repeated-sprint performance, in addition to investigating if caffeine in the afternoon would potentiate performance compared with the morning. Thirteen physically active men took part in this randomized, double-blind, placebo-controlled and crossover study. All participants underwent a repeated-sprint ability test (10 × 6 s cycle sprints, with 30 s of rest) at 60 min after ingestion of either 5 mg·kg-1 or placebo under 4 different conditions: morning with caffeine ingestion, morning with placebo ingestion, afternoon with caffeine ingestion, and afternoon with placebo ingestion. Total work, peak power (PP) and anaerobic power reserve (APR) were assessed. Oxygen uptake, heart rate, lactate concentration, and rating of perceived exertion were also measured during the repeated-sprint test. Total work (+8%, d = 0.2, small), PP (+6%, d = 0.2), and APR (+9%, d = 0.2) were significantly higher in the afternoon when compared with morning. However, physiological responses were not different between caffeine and placebo conditions. Repeated-sprint (10 × 6 s cycle sprint) performance was influenced by time of day, with lower performance in the morning compared with the afternoon. However, caffeine supplementation did not prevent the reduction in performance in the morning or improve performance in the afternoon.