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  • Author: Bianca Miarka x
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Montassar Tabben, Bianca Miarka, Karim Chamari and Ralph Beneke

Purpose: To evaluate the concept of decisive moment (DM) as a novel analysis approach providing insights into factors leading to successful high-performance k umite karate outcomes using time–motion variables. DM represents the moment from which 1 of the 2 opponents uninterruptedly dominates the other until the end of the fight. Methods: A total of 120 elite seniors (60 men and 60 women) World Karate Federation combats were analyzed during 2 World Championships (2012 and 2014). Specific characteristics of karate combat (strategy, technique, tactic, target, and effectiveness) were evaluated and classified in 3 sections: at, before, and after DM. Results: DM occurred at about 49% (32.8%) of bout duration. Up to DM no clearly identifiable differences in performance characteristics were found between winners and losers. At and after DM, an offensive strategy with focus on upper-limb techniques, attack and counterattack, targeting the head showed highest potential to achieve and maintain dominance and to win. After DM, losers showed increasingly reactive techniques, mainly timed attacks and combinatory techniques. Conclusion: The DM concept presents a novel approach to time–motion analysis, which for the first time allowed identification of clear discriminating factors of success and defeat in kumite karate at the highest performance level.

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Maamer Slimani, Helmi Chaabene, Bianca Miarka and Karim Chamari

Purpose:

To determine the performance aspects (time–motion and technical-tactical analysis) of top-level low-kick kickboxers according to gender, weight category, combat round, and match outcome.

Methods:

Seventy-two kickboxers (44 male, 28 female) were studied. Thirty-six bouts (male = 61, female = 41 rounds) were analyzed using a time–motion system. Time structure was classified into 3 phases: preparatory-activity time (PT), fighting time (FT), and stoppage time (ST).

Results:

Referee decisions caused an overall effort:pause ratio (E:P) of ~1:1.5, with a significant difference between weight categories (light and middleweights = 1:1.5, heavyweight = 1:1). This ratio was ~1:6 when high-intensity actions–to-pause activities were considered. Significant differences were also observed between rounds (all P < .001), with 1st-, 2nd-, and 3rd-round E:Ps of 1:1, 1:1.5, and ~1:2, respectively. The relative times of FT and PT, total attacking actions, upper-limb actions, number of technical actions performed on the head, and the number of high-intensity actions were higher in males than females (all P = .05). Males performed more jab-cross actions and fewer low kicks than females (P < .001). Males used upper-limb (63.4%) more than lower-limb techniques (36.6%), targeting the head (56.9%) more than the body/leg (43.1%), with no significant difference from females (P > .05). E:P was similar between winners and losers. However, the numbers of technical actions performed on the head, counterattack actions, jab-cross technique, and total punches were higher in winners than losers (all P < .05).

Conclusions:

Training programs need to be adapted to the specific requirements of kickboxers’ weight categories and gender to develop the technical-tactical abilities that improve athletes’ chances of winning.

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Bianca Miarka, Katarzyna Sterkowicz-Przybycien and David H. Fukuda

The purpose of the present study was to create a probabilistic neural network to clarify the understanding of movement patterns in international judo competitions by gender. Analysis of 773 male and 638 female bouts was utilized to identify movements during the approach, gripping, attack (including biomechanical designations), groundwork, defense, and pause phases. Probabilistic neural network and chi-square (χ2) tests modeled and compared frequencies (p ≤ .05). Women (mean [interquartile range]: 9.9 [4; 14]) attacked more than men (7.0 [3; 10]) while attempting a greater number of arm/leg lever (women: 2.7 [1; 6]; men: 4.0 [0; 4]) and trunk/leg lever (women: 0.8 [0; 1]; men: 2.4 [0; 4]) techniques but fewer maximal length-moment arm techniques (women: 0.7 [0; 1]; men: 1.0 [0; 2]). Male athletes displayed one-handed gripping of the back and sleeve, whereas female athletes executed a greater number of groundwork techniques. An optimized probabilistic neural network model, using patterns from the gripping, attack, groundwork, and pause phases, produced an overall prediction accuracy of 76% for discrimination between men and women.

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Helmi Chaabène, Emerson Franchini, Bianca Miarka, Mohamed Amin Selmi, Bessem Mkaouer and Karim Chamari

Purpose:

The aim of this study was to measure and compare physiological and time–motion variables during karate fighting and to assess eventual differences between winners and defeated elite karatekas in an ecologically valid environment.

Methods:

Fourteen elite male karatekas who regularly participated in national and international events took part in a national-level competition.

Results:

There were no significant differences between winners and defeated karatekas regarding all the studied variables. Karatekas used more upper-limb (76.19%) than lower-limb techniques (23.80%). The kisami-zuki represented the most frequent technique, with 29.1% of all used techniques. The duration of each fighting activity ranged from <1 s to 5 s, with 83.8% ± 12.0% of the actions lasting less than 2 s. Karatekas executed 17 ± 7 high-intensity actions per fight, which corresponded to ~6 high-intensity actions per min. Action-to-rest ratio was about 1:1.5, and high-intensityaction- to-rest ratio was ~1:10. The mean blood lactate response at 3 min postcombat (Lapost) elicited during karate fighting was 11.18 ± 2.21 mmol/L (difference between Lapre and Lapost = 10.01 ± 1.81 mmol/L). Mean heart rate (HR) was 177 ± 14 beats/min (91% ± 5% of HRpeak). Karatekas spent 65% of the time exercising at HR >90% of the individual HRpeak.

Conclusion:

Karatekas predominantly use upper-limb karate techniques. Karate’s nature is intermittent, with fighting activities representing ~6% of total combat’s duration and ~84% of actions lasting less than 2 s, with ~21-s mean time interval in between. Kumite combat sessions induced high La and near-maximal cardiovascular strain. Other key success factors should be investigated to properly discriminate winners and defeated athletes.

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Bianca Miarka, Fábio Dal Bello, Ciro J. Brito, Fabrício B. Del Vecchio, John Amtmann and Karim Chamari

Purposes: To determine actions during bouts that generate serious enough injury to stop the bout; verifying the injury incidence, types, and prevalence of doctor stoppages (doc-stoppage); and identify potential risk factors by analyzing technical-tactical profiles for injury in sanctioned mixed martial arts bouts taking place over a 12-y period. Methods: This research analyzed 440 paired mixed martial arts matches separated by doc-stoppage (n = 220) and no doc-stoppage (n = 220) from 2002 to 2014. Technical knockouts for doc-stoppage were diagnosed and managed by attending ringside doctors, and the time–motion variables were categorized into total combat time separated by low- or high-intensity activities per round, stand-up, or groundwork actions, P ≤ .05. Results: The main cause of injuries in doc-stoppage situations was due to facial injuries (>90%), with 87.1% occurring after striking actions during the second round. Lacerations were the leading type of injury, which occurred with 80% frequency. The results showed differences between doc-stoppage and no doc-stoppage for standing combat with low-intensity actions (130.6 [8.5] s vs 83.3 [6.9] s for first round; 115.7 [10.5] s vs 100.1 [9.6] s for second round, and 121.5 [19.5] s vs 106.3 [11.7] s for third round) and total strike attempts (34.5, 23.0–51.8 vs 25.0, 12.0–40.8); in standing combat, head strike attempts (21, 10–33 vs 11, 4–21) and body strikes (2.5, 1.0–5.8 vs 1.0–2), and in groundwork combat, head strikes landed (0.0–3.0 vs 0.0–5.0). Conclusions: This research showed higher values of strike attempts with 2 main orientations, namely the head (on the ground and in stand-up actions) and body (in stand-up actions), and may provide important information regarding the technical knockout and when it can be called by officials supervising mixed martial arts bouts.

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Victor Silveira Coswig, Bianca Miarka, Daniel Alvarez Pires, Levy Mendes da Silva, Charles Bartel and Fabrício Boscolo Del Vecchio

We aimed to describe the nutritional and behavioral strategies for rapid weight loss (RWL), investigate the effects of RWL and weight regain in winners and losers, and verify mood state and technical–tactical/time–motion parameters in mixed martial arts. The sample consisted of mixed martial arts athletes after a single real match and was separated into two groups: winners (n = 8; age: 25.4 ± 6.1 years, height: 173.9 ± 0.2 cm, habitual body mass: 89.9 ± 17.3 kg) and losers (n = 7; age: 24.4 ± 6.8 years, height: 178.4 ± 0.9 cm, habitual body mass: 90.8 ± 19.5 kg). Both groups exhibited RWL and weight regain, verified their macronutrient intake, underwent weight and height assessments, and completed two questionnaires (Profile of Mood States and RWL) at (a) 24 hr before weigh-in, (b) weigh-in, (c) postbout, and (d) during a validated time–motion and technical–tactical analysis during the bout. Variance analysis, repeated measures, and a logistic regression analysis were used. The main results showed significant differences between the time points in terms of total caloric intake as well as carbohydrate, protein, and lipid ingestion. Statistical differences in combat analysis were observed between the winners and losers in terms of high-intensity relative time (58 [10–98] s and 32 [1–60] s, respectively), lower limb sequences (3.5 [1.0–7.5] sequences and 1.0 [0.0–1.0] sequences, respectively), and ground and pound actions (2.5 [0.0–4.5] actions and 0.0 [0.0–0.5] actions, respectively), and logistic regression confirmed the importance of high-intensity relative time and lower limb sequences on mixed martial arts performance. RWL and weight regain strategies were related to technical–tactical and time–motion patterns as well as match outcomes. Weight management should be carefully supervised by specialized professionals to reduce health risks and raise competitive performance.

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Diego Alves dos Santos, Bianca Miarka, Fabio dal Bello, Andreia Cristiane Carrenho Queiroz, Pedro Henrique Berbert de Carvalho, Ciro José Brito and Ralph Beneke

This study verified the performance probabilities by mixed martial arts rounds by the same athletes, doing paired comparisons of time–motion and actions before and after 10 y. The sample was composed of 845 Ultimate Fighting Championship rounds of 45 athletes separated into before (M1, age range 34–44 y) and after (M2, age range 44–54 y). Motor-control (takedowns, submissions, chokes, locks, strike actions to the head, and body and leg strikes attempted and landed) and time–motion (high and low intensities and standing and ground times) analyses were done. The main results showed significant differences (P ≤ .05) in total strikes landed (M1 22 [13; 34] > M2 18 [10; 31.7]), total strikes attempted (M1 41 [24.5; 62] > M2 35 [21; 48]), single head strikes attempted (M1 19 [9; 34.5] > M2 16.5 [9; 28]), single body strikes landed (M1 1 [0; 4] > M2 1 [0; 2]), single body strikes attempted (M1 2 [0; 5] > M2 1 [0; 3]), takedowns attempted (M1 1 [0; 2] > M2 1 [0; 2]), standing combat time (M1 2:10.28 [1:38.95] > M2 1:55.56 [1:32.17]), and low-intensity time (M1 2:11.45 [1:38.95] > M2 1:56.26 [1:31.89]). Variables that increased the probability to be associated with over the years were body strikes landed, head strikes landed, total strikes landed, and single strikes attempted, whereas body strikes attempted, head strikes attempted, total strikes attempted, and submission attempted had a negative association with mixed martial arts years of experience. Therefore, M2 athletes should be focused on standing combat time combined with strikes-landed actions, targeting the head—it has the highest potential performance probability and avoid unsuccessful body-strike attempts and submissions—which has the lowest potential performance probability over 10 years.