Background : Rare are the studies which treated the effect of training and successive fights of karate on haemodynamic and blood lactate concentrations responses. Objectives : To evaluate and analyze the aerobic capacity of elite Congolese karate athletes, as well as their haemodynamic and blood lactate concentrations responses changes during Ruffier test and stimulated competition. Methods : Twelve karate athletes (6 seniors and 6 juniors) took part in the study. These karate athletes were selected within the national karate teams (senior and junior) of Congo-Brazzaville. Anthropometric, bioenergetic and haemodynamic (HR, SBP, DBP) parameters and blood lactate [La] concentrations were measured at rest, immediately after the end of Ruffier test and each fight (n = 3). Results : Peak aerobic power (PAP) and maximum oxygen uptake (VO 2 max) values averaged 437 ± 23 watts and 57.61 ± 2.2 ml/kg/mn, values varying as function as age division (senior vs junior). The recovery index was 5.4 ± 3.4 for juniors and 6.8 ± 3.2 for seniors. SBP, HR and [La] concentrations increased significantly during fights, compared to the resting values. HR max w as 182.3 ± 1.6 bpm (89% theor eti cal HR max ) for seniors and 182.0 ± 13.5 bpm (86% theor eti cal HR max ) for juniors. Peak [La] concentrations were 10.3 ± 1.5 mmol/l for seniors and 10.8 ± 1.2 mmol/l for juniors. Conclusion : Congolese karate athletes call upon high levels of the anaerobic and aerobic capacities. The karate training program in Congo should emphasize more gold improvising lower body anaerobic power and endurance.
Karate is a martial art of Japanese origin, attack and defense using the arms and legs [
The study, observational and experimental, was carried out from September 27 2019 to October 9 2019 in Brazzaville, Congo-Brazzaville. The sample of study was made up starting from the karate athletes qualified with the national karate championship. To participate in this study, a clinical examination and an electrocardiogram made it possible to determine the following medical history: neuropathy, unstable angina, history of effort syncope, tight aortic stenosis or obstructive cardiomyopathy; karate athletes not presenting these exclusion criteria and those not carrying associated pathologies or cardiorespiratory complications were selected. Other exclusion criteria were: taking medication that could affect metabolism or change body; participation in a rapid weight loss (2% - 10%) program for competing in a designated weight category. Twelve sportsmen, all black belts and no smokers, were included in the study after written informed agrees. They were distributed according to the age in 6 seniors (20 - 30 years, 24.7 ± 3.5 years) and 6 juniors (16 - 19 years, 17.1 ± 1.2 years). They have 7 years of training experiment. Seven subjects took part in at least an international competition, the others with a national tournament. Among the first subjects, among then two of the subjects had obtained a silver medal to African Games 2015. The study received the approval of the National Committee of Ethics for Research in Health Sciences. Employment status of each subject was assessed by the question, “Are you currently working?”. Consumption of alcohol was determined based on the respondent’s declaration of drinking alcohol (not drinking or formerly drinking alcohol). Participants were also categorized for smoking status as current smokers, ex-smokers, and non-smokers.
During the period of study, the time volume of training was 15 hours per week, at a rate of 3 hours per day, to Monday on Friday. A training session was generally made up of three parts: physical preparation, technico-tactic specific training to karate (including fights) and recovery period. The physical training (duration one hour per meeting) associated limbering up exercises, games, muscular exercises and jogging (from 30 - 45 minutes during Sunday). The athletes who did not enjoy a perfect health at the time the study and at least 3 months before, and the irregular athletes at training sequences were excluded from the study. Concerning the technico-tactic training, HR, SBP, DBP and lactatemia were measured at half-course and at the end of precompetitive period; the meetings proceeded to 70% - 99% of theoretical HRmax. Durations of meetings were in conformity with those recommended by the International Karate Federation, in the two categories of age.
Anthropometric measurements consisted of the determination of weight using electronic balance to nearest 100 g (Seca Instruments Ltd., Hamburg, Germany), height and percentage of fatty mass (% FM) evaluated from the 4 cutaneous skinfolds (biceps, triceps, subscapular, iliac-crest) using Harpenden caliper (Lange, Cambridge, MA, USA), according to formula of Durnin and Rahaman [
HR measurements were taken during Ruffier test and a series of fights. Ruffier test made it possible to evaluate the cardiac recovery capacity of a subject following a submaximal exercise. Ruffier test [
A continuous exercise with increasing load on ergocycle allowed the determination by direct measurement of PAP and VO2 max, using an automated system of measurement of gaseous exchanges (CPX, Medical Graphics, Munich, Germany). The test started with a heating of 3 min to 30 watts. For the determination of PAP, cycling frequency was fixed at 75 rpm, the power at the first stage was 75 w, and the increments at 30 w. Duration at the first stage was 4 min and that of the 2 minute old following. The test was stopped when the subject did not manage anymore to maintain imposed cycling frequency, in spite of the lavished encouragements. PAP value corresponds to the power supported at the last stage of this test. However, when this one was stopped before its term. Value of selected power was calculated according to following procedure:
PAP = Pcomplete + ∆P × t/t stage
where Pcomplete is the power at the last stage carried out completely, t the time of cycling put at the last incomplete stage, t stage the time of a complete stage and ∆P the increment of power for each stage.
With regard to determination of VO2 max, the load increased by 30 w/min except at the end of the test where the increase was reduced to 20 w/min in order to approach in a precise way measurement of the maximal parameters. A valid VO2 max was obtained when at least 2 of these 3 criteria were met: 1) plateau in VO2 lower than 200 ml/min in spite of increasing work rate, 2) maximal HR > 90% of predicted theoretical maximum HR according to formula [
Blood lactate concentrations were measured using the instructions of the KDK Corporation (Lactate Pro-LT 1710, Tokyo, Japan). The taking away were carried out on the level of the index, at rest and at the end of each fight. All measurements were carried out in an identical way with the same material, according to the same protocol and in the same room of fight.
During the experimentation, each subject was regarded as its own witness. A meeting of familiarization with the experimental protocol and the material was carried out for each subject. At this meeting of familiarization, the unfolding of fights was carried out with a cardiofrequencemeter similar to that used in the experimentation. If VO2 max were measured at a subject at rest before the series of fights, HRmax, SBP and DBP were measured at rest and during the phases of fight. Each subject carried out a fight with the same partner of the same weight category. Each karate meeting included/understood a cardiovascular activation, an articular and muscular heating, and a specific heating of karate. Lastly, the 2 min 30 of fight took place. The time of fight being an effective time, it was proceeded to a chronometric statement of the durations of the various phases of work and recovery to facilitate the analysis of results. The combat organized in return ticket were spaced one day. To work out the situations of karate fight, we took into account two constraints: on the one hand the brittleness of portable cardiofrequencemeter and on the other hand, the concern of preserving the uncertainty (characteristic of the combat sports which gives the possibility for the two protagonists of gaining).
Data are expressed on mean ± standard deviation. The comparison of two means was carried out using Student t test for paired series. The variations of HR, SBP and DBP values, [La] concentrations between the rest and the end of each fight were examined by an ANOVA with one way and 4 factors. Thereafter, the post hoc Scheffe test made it possible to specify between which levels these differences were exactly. Differences were considered statistically significant when p < 0.05. Statistical analysis was performed using the SPSS/PC Statistical Social Package for Science (version 23.0).
Examination of morphological data (
Seniors (n = 6) | Juniors (n = 6) | |
---|---|---|
Anthropometric data | ||
Height (cm) | 170.4 ± 3.9 | 163.5 ± 3.4 |
Weight (kg) | 65.1 ± 2.6 | 58.3 ± 3.8 |
BMI (kg/m2) | 22.4 ± 1.2 | 22.8 ± 1.3 |
Leg length (cm) | 98.2 ± 2.7 | 95.4 ± 3.5 |
Arm length (cm) | 76.3 ± 2.2 | 73.5 ± 3.4 |
Body fat (%) | 11.2 ± 2.2 | 10.7 ± 2.2 |
Demographic data | ||
Employment status | ||
Yes | 6 | 2 |
No | 0 | 4 |
Years at school, mean (SD) | 16.43 (3.57) | 10.59 (2.11) |
Educational status | ||
High school | 04 | 05 |
University | 02 | 01 |
Clinical status | ||
Alcohol intake, n (%) | ||
Drinker | 02 (100) | 00 |
Former drinker | 01 (100) | 00 |
Non drinker | 03 (33.4) | 06 (66.6) |
Smoking | ||
Current smoker | 01 (100) | 00 |
Ex-smoker | 01 (100) | 00 |
Non smoker | 04 (40) | 06 (60) |
Abbreviation: BMI, body mass index.
HR, SBP and DBP values at rest (
HR, SBP and DBP values at rest and at the end of Ruffier test are presented in
PAP and VO2 max values are shown in
The evolution of the HR during 3 fights is described in
Seniors (n = 6) | Juniors (n = 6) | P | |
---|---|---|---|
HR0 (bpm) | 76.2 ± 9.4 | 72.7 ± 11.3 | NS |
SBP0 (mmHg) | 118.2 ± 10.2 | 116.7 ± 9.3 | NS |
DBP0 (mmHg) | 85.6 ± 1.6 | 87.1 ± 1.3 | NS |
RI | 6.8 ± 3.2 | 5.4 ± 3.4 | NS |
Abbreviations: HR0, heart rate at rest; SBP0, systolic blood pressure at rest; DBP0, diastolic blood pressure at rest; RI, recuperation index.
Rest | End of Ruffier test | P | |
---|---|---|---|
Seniors (n = 6) | |||
HR (bpm) | 76.2 ± 8.3 | 148.6 ± 10.3 | < 0.05 |
SBP (mmHg) | 118.2 ± 4.2 | 132.8 ± 2.5 | < 0.001 |
DBP (mmHg) | 85.6 ± 1.6 | 87.8 ± 1.2 | NS |
Juniors (n = 6) | |||
HR (bpm) | 72.7 ± 7.5 | 145.3 ± 9.7 | < 0.05 |
SBP (mmHg) | 116.7 ± 3.9 | 134.3 ± 3.2 | < 0.001 |
DBP (mmHg) | 87.1 ± 1.3 | 88.5 ± 1.1 | NS |
Abbreviations: HR, heart rate; SBP, systolic blood pressure; DBP, diastolic blood pressure.
All group (n = 12) | Seniors (n = 6) | Juniors (n = 6) | P | |
---|---|---|---|---|
PAP (watts) | 437 ± 23 | 440.7 ± 24.2 | 433.3 ± 21.8 | >0.05 |
VO2 max (ml/kg/min) | 57.6 ± 2.2 | 58.5 ± 1.8 | 56.7 ± 2.6 | >0.05 |
VO2 max (l/min) | 3.50 ± 0.25 | 3.41 ± 0.27 | 3.59 ± 0.24 | >0.05 |
Abbreviations: PAP, peak aerobic power; VO2 max, maximum oxygen consumption.
analysis showed that as compared to HR values at rest, HR increased significantly between first and third fights in the two age groups, to reach 185.3 ± 2.2 bpm in the senior athletes (F = 15.2; p < 0.001) and 181.7 ± 1.5 bpm among juniors (F = 16.5; p < 0.001), in comparison to values at rest. The rough HR obtained at the end of the third fight represented high percentages compared to the theoretical HRmax. No significant difference was found between juniors and seniors at the time of various fights [end of 1st fight: 152.4 ± 20.1 (72%) bpm vs 160.3 ± 19.4 (78%) bpm; end of 2nd fight: 180.4 ± 12.6 (85%) bpm vs 175.8 ± 14.1 (86%) bpm; end of 3rd fight: 182.0 ± 13.5 (86%) bpm vs 182.3 ± 13.6 (89%) bpm].
In the whole of the subjects, SBP values increased significantly compared to the values at rest (
Blood lactate concentrations (
difference of [La] concentrations between juniors and seniors at the time of the various fights [end of 1stfight: 5.3 ± 0.7 mmol/l vs 4.9 ± 0.5 mmol/l; end of 2ndfight: 7.2 ± 1.0 mmol/l vs 6.8 ± 0.5 mmol/l; end of 3rdfight: 10.8 ± 1.2 mmol/l vs 10.3 ± 1.5 mmol/l].
This study shows mainly that the specific karate exercises and the simulated competition significantly affect the evolution of HR, SBP and [La] concentrations in the athlete. Data obtained reveal that age, weight and height of our subjects (
[
It is about a dynamic and submaximal test a minima. Its total energy cost in 45 s estimated at 27.8 ± 1.95 ml STPD/kg, cardiac cost at 101 beats (60 to 144) and oxygen debt at 22.2 ± 5 ml STPD/kg [
Thus, the adaptation slower to the recovery of our karate athletes testifies to an increase in peripheral resistances, accused in the opposition to the modifications induced by physical exercise. Moreover, it is known that values of the relaxation time differ according to capacities from adaptation in hot medium surrounding [
Our work also highlighted the superiority of our HR values in comparison to those noted by MassambaMiabaou et al. [
In addition, our data show that the distribution of the blood pressure values at rest (
Moreover, HR values were increasing throughout the 3 fights, ranged between 72% - 89% of the theoretical HRmax (
Finally, a fight of karate can be regarded as an intermittent anaerobic exercise, which is close to the concept of alternatively aerobic and anaerobic activity proposed byDel Monte and Menchinelli [
Our study showed that the karate Congolese experts have a moderate recovery capacity and a required aerobic capacity. The evolution of HR, SBP and [La] concentrations during fights shows the importance of anaerobic and aerobic metabolisms to karate practice. This work thus makes it possible to validate the reliability of variables: HR, SBP, DBP, blood lactate concentrations to discriminate a certain number of karate experts during a selection starting from the cardiovascular and metabolic criteria relevant. Thus, the karate trainer, in the sub-Saharan African environment, can start from these criteria simple and easy to implement to build a system of control of training.
The authors gratefully thank Dr. Martin Mvitu for excellent scientific devices and technical assistance, to Dr. Joseph Bonazebi for statistical treatment. We would like to particularly thank all participants who made by to their authorities and commitment this possible study.
MJGA designed the study, participated in the implementation of experimental procedure and wrote the first version of the article. MJM, MELS and MKFN were involved in the acquisition of field data. PTB and MBJR have validated the experimental procedure and reread the first version of article. MA performed the statistical analysis of data and reread the final version of the article that has received the approval of all authors.
None.
Moulongo, J.G.A., Moussoki, J.M., Massamba, E.L.S., Massala Kitanga, F.N., Packa Tchissambou, B., Mabiala Babela, J.R. and Massamba, A. (2020) Recovery Capacity, Haemodynamic and Blood Lactate Changes during Training and Competition in Elite Congolese Karate Athletes. World Journal of Cardiovascular Diseases, 10, 257-273. https://doi.org/10.4236/wjcd.2020.105024