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Changes in selected physical, motor performance and anthropometric components of university-level rugby players after one microcycle of a combined rugby conditioning and plyometric training program
No full textPienaar, C and Coetzee, B. Changes in selected physical, motor performance and anthropometric components of university-level rugby players after one microcycle of a combined rugby conditioning and plyometric training program. J Strength Cond Res 27(2): 398–415, 2013. The purpose of this study was to determine the effects of a microcycle (4 weeks) combined rugby conditioning plyometric compared with a nonplyometric rugby conditioning program on selected physical and motor performance components and anthropometric measurements of university-level rugby players. Players (18.94 ± 0.40 years) were assigned to either a control (n = 16) or experimental group (n = 19) from the U/19 rugby teams of the North-West University (South Africa). Twenty-six direct and indirect anthropometric measurements were taken, and the players performed a battery of 5 physical and motor performance tests before and after a microcycle (4 week) combined rugby conditioning plyometric (experimental group) and a nonplyometric rugby conditioning program (control group). The dependent t-test results showed that the control group's upper-body explosive power decreased significantly, whereas the stature, skeletal mass, and femur breadth increased significantly from pre- to posttesting. The experimental group showed significant increases in wrist breadth, speed over 20 m, agility, and power and work measurements of the Wingate anaerobic test (WAnT). Despite these results, the independent t-test revealed that speed over 20 m, average power output at 20 seconds, relative work of the WAnT, and agility were the only components of the experimental group that improved significantly more than the control group. A microcycle combined rugby conditioning plyometric program therefore leads to significantly bigger changes in selected physical and motor performance components of university-level rugby players than a nonplyometric rugby conditioning program alone. Based on these findings, coaches and sport scientists should implement 3 weekly combined rugby conditioning plyometric programs in rugby players' training regimens to improve the players' speed, agility, and power
The use of heart rates and graded maximal test values to determine rugby union game intensities
No full textThe aim of this study was to determine the intensities of university rugby union games using heart rates and graded maximal test values. Twenty-one rugby players performed a standard incremental maximal oxygen uptake (V[Combining Dot Above]O2max) test to the point of exhaustion in the weeks between 3 rugby matches. The heart rates that corresponded to the first and second ventilatory thresholds were used to classify the heart rates into low-, moderate-, and high-intensity zones. The heart rates recorded through heart rate telemetry during the matches were then categorized into the different zones. The average heart rates for the different intensity zones as well the percentages of the maximum heart rate (HRmax) were as follows: low, 141–152 b·min−1 (76.2–82.0% HRmax); moderate, 153–169 b·min−1 (82.7–91.4% HRmax); and high, 170–182 b·min−1 (91.9–100% HRmax). The percentages of time players spent in the different intensity zones were as follows: 22.8% for the low-intensity, 33.6% for the moderate-intensity, and 43.6% for the high-intensity zones. The dependant t-test revealed significant differences (p < 0.05) between the low- and high-intensity zones for the second halves, between the low- and moderate- as well as between the low- and high-intensity zones for the matches overall. To conclude, the results of the study showed that the above-mentioned method can be used to determine the intensities of university rugby union games. It also revealed that university rugby games are categorized by significantly more high-intensity activities than was previously reported by other rugby match analyzing–related studies. Thus, sport scientists and conditioning coaches should concentrate more on high-intensity activities for longer periods during training sessions
Comparative effect of land- and aquatic-based plyometric training on jumping ability and agility of young basketball players
No full textThe effect of land- and aquatic-based plyometric training on jumping ability and agility of young basketball players was investigated. Eighteen young male, semi-professional basketball players (age: 18.81±1.46 years) were randomly assigned to aquatic plyometric training (AP), land plyometric training (LP) or a control group (CON). The plyometric training groups were subjected to an 8-week long plyometric training program that consisted of three plyometric training sessions per week of 40 minutes per session. The players performed jumping ability and agility tests before and after the training or non-training period. The 2×3 analysis of variance and Tukey post hoc test revealed no significant differences (p>0.05) between the AP and LP for any of the jumping ability and agility test values. A significant training effect (p<0.05) was seen in the experimental groups (AP and LP) for all the test variables from pre- to post-training. Significantly greater gains were observed with regard to all measurements in the AP compared to the CON. The LP only achieved significant greater gains in the Vertical Jump Test compared to the CON. The 8-week aquatic-based plyometric training program provided the same or more benefits for jumping and agility ability of young basketball players than the land-based plyometric training program of the same duratio
The use of anthropometric measurements and the Influence of demographic factors on the prediction of vo2max in a cohort of adolescents: the Pahl study
No full textBackground:
prediction models have not focused on children and adolescents from South Africa and have not included various demographic factors as possible predictors.
Aim: The purpose of this study was, therefore, to determine whether a valid prediction function can be developed from several anthropometric measurements and demographic factors of a cohort of adolescents in South Africa.
Subjects and methods: A total of 214 adolescent boys (n = 88) and girls (n = 126) (15.82 ± 0.68 years) were selected. Demographic, sport and maturation data were collected by means of questionnaires, whereas anthropometric measurements were taken by accredited anthropometrists and the 20-m Shuttle Run Test (SRT) executed to determine indirect
values. A forward stepwise multiple regression analysis was performed to identify the cluster analysis reduced
predictors and a cross-validation was performed in order to validate the prediction function.
Results: Muscle mass percentage, sport participation level, stature, hip circumference and ectomorphy acted as significant predictors (p < 0.05) of the adolescents’ indirect, 20-m SRT values. Seventy per cent of the variance in the indirect, 20-m SRT
values could be explained by this model. Cross-validation also confirmed the model’s validity.
Conclusion: Results indicate that the of adolescents from different racial backgrounds, living areas and gender groups can be accurately predicted by making use of a population-specific model
Relationship between autonomic markers of heart rate and subjective indicators of recovery status in male, elite badminton players
Full text linkThe primary aim of the study was to determine if heart rate variability (HRV), and heart rate recovery (HRR) are related to several subjective indicators of recovery status (muscle soreness, hydration status, sleep quality and quantity as well as pre-competition mood states) for different match periods in male, elite, African, singles badminton players. HRV and HRR were measured in twenty-two badminton players before (pre-match), during (in-match), after (post-match) and during rest periods (in-match rest) of 46 national and international matches. Muscle soreness, hydration status, and sleep quality and quantity were measured on a daily basis whereas mood states were measured just before each match via questionnaires. Prior to each match warm-up, players were fitted with a Fix Polar Heart Rate Transmitter Belt to record heart rate every second during each match and HRR during service breaks and after matches. Kubios HRV software was used for final HRV analyses from the series of R-R-intervals. A strong, significant canonical correlation (Rc = 0.96, p = 0.014) was found between HRV, HRR and subjective indicators of recovery status for the in-match period, but only strong, non-significant relationships were observed for pre-match (Rc = 0.98, p = 0.626) and post-match periods (Rc = 0.98, p = 0.085) and a low non-significant relationship (Rc = 0.69, p = 0.258) for the in-match rest period. Canonical functions accounted for between 47.89% and 96.43% of the total variation between the two canonical variants. Results further revealed that Ln-HFnu, the energy index and vigour were the most prominent variables in the relationship between the autonomic markers of heart rate and recovery-related variables. In conclusion, this study proved that subjective indicators of recovery status influence HRV and HRR measures obtained in a competitive badminton environment and should therefore be incorporated in protocols that evaluate these ANS-related parameter
Notational singles match analysis of male badminton players who participated in the African Badminton Championships
No full textPurposes of this study were firstly, to determine the notational singles match analysis results of male badminton players and secondly, to determine relationships between notational singles match analysis determined strokes and foot movements in male badminton players, who participated in the African Badminton Championships. Twenty male singles matches from the team and individual events of the 2014 All Africa Badminton Championships were recorded live via video cameras and analysed using the Dartfish video analysis software package. Average match duration (1470.4 s), real time (432.9 s) and percentage of real time played (29.8%), number of rallies per match (68.4) and shots per rally (6.5) were calculated. Average shots per rally were found to be 6.5 and the work density, .4. Average stroke frequency per match was: drive – 122.1, clear – 118, smash – 56.2, net strokes – 54.3, drop-shot – 24.2 and the round-the-head stroke – 1.2. Foot movements delivered the following average results per match: chasse-step – 174.6, shuffle – 161.7, split-step – 61.6, half-lunge – 52.20, forward-lunge – 46.1 and scissors kick – 38.3. Significant Spearman Rank Correlation Coefficients existed between various foot movements and strokes. The study confirmed the applicability of computerised notational analyses in determining singles badminton match characteristic
Die antropometriese vloeritem-prestasiedeterminante van jong dogtergimnaste
No full textThe purposes of this study were firstly, to determine the anthropometric variables that differ significantly (p 0.05) between successful and less successful young, South-African female gymnasts who participate in the floor item and secondly, to determine the anthropometric variables that contribute to the floor item performance of those gymnasts. Twelve young, female gymnasts (13.39 ± 2.14 years) from a gymnastics club in the North-West Province of South Africa participated in the study. Only gymnasts who participated at level 6-9 and junior as well as senior Olympic level were selected to participate in the study. Sixty-one anthropometric variables were measured on the dominant side of the body according to the methods of Norton et al. (1996). Independent t-tests revealed that the gymnast who obtained the highest marks (top 5) during the execution of the floor item during the South African Gymnastics Championships had statistical and practical significantly larger relaxed and flexed upper arm, wrist and ankle circumferences as well as mesomorphy values than the less successful gymnasts. The cluster analysis-reduced variables were used to perform a forward, stepwise multiple regression analysis which showed that bi-trochanterion (34.86%), femur (17.07%) and bi-deltoid breadth (4.93%); front thigh skinfold (19.71%); fat percentage (7.68%); acromialradial (4.09%) and foot length (0.05%) as well as waist (6.68%), chest (2.92%) and gluteal thigh circumference (2.02%) contributed 100% to the variance in gymnasts’ floor performances. The contributions of bi-trochanterion breadth, femur breadth, gluteal thigh circumference and foot length to floor-gymnastic performance were significant. Only gluteal thigh circumference showed a negative relationship with floor-gymnastic performance. The conclusion that can therefore be drawn is that larger limb and torso circumferences, waist breadths, fat percentages and front thigh skinfolds, as well as upper arm and foot lengths are important anthropometric floor performance determinants for young, South African female gymnasts and should be included in the sports-scientific testing protocols of gymnasts.Key words: Gymnastics; Floor; Anthropometry; Performance; Females; Girls
Die antropometriese sprongitem-prestasiedeterminante van jong dogtergimnaste
No full textThe purposes of this study were firstly to determine the anthropometric variables that differ significantly (p ≤ 0.05) between successful and less successful young, South-African (SA), female gymnasts in the vault item and secondly, to determine the anthropometric variables that contribute to the performance of young SA female gymnasts in the vault item. Twelve young, female gymnasts (13.39 +- 2.14 years) from a gymnastics club in the North-West Province of South Africa participated in this study. Only gymnasts who participated at level 6-9 and junior as well as at the senior Olympic level were selected to participate in this study. Sixty-one anthropometric variables were measured on the dominant side of the body according to the methods of Norton et al. (1996). Independent t-tests and effect sizes revealed that the gymnasts who obtained the highest points (top 5) during the execution of the vault item during the South African Gymnastics Championships had statistical and practical significantly larger relaxed and flexed upper arm, wrist and ankle circumferences as well as higher mesomorphy values than the less successful gymnasts. The cluster analysis-reduced variables were used to perform a forward, stepwise multiple regression analysis, which showed that flexed upper arm circumference (53.93%), midstillion dactillion length (12.38%), foot length(11.50%), fat percentage (8.93%), trochanterion-tibial lateral length (5.77%), chest circumference (3.69%), ectomorphy (1.96%), bideltoied breadth (1.54%), triceps skinfold (0.23%) and iliospinal box height (0.07%) contributed 100% to the variance in gymnasts’ vault performances. Therefore the conclusion that can be drawn is that larger upper arm and upper body circumferences; hand, foot, upper leg and total leg lengths; triceps skinfold and fat percentage as well as a higher ectomorphy value are important anthropometric vaulting performance determinants for young, South African, female gymnasts and should be included in the sport-scientific testing protocols of gymnasts.Key words: Gymnastics; Vault; Anthropometry; Performance; Female; Girls
Laboratory-Based Physical and Physiological Test Results That Serve as Predictors of Male, Amateur Road Cyclists' Performance Levels
No full textLaboratory-based physical and physiological test results that serve as predictors of male, amateur road cyclists' performance levels. J Strength Cond Res 32(10): 2897–2906, 2018—The purposes of this study were first, to determine the practical significant differences of laboratory-based physical and physiological test results between a selected group of successful and less successful amateur, male road cyclists from Africa; and second, to determine the significance, adequacy, accurateness, and usefulness of laboratory-based physical and physiological test results to serve as predictors of these amateur, male road cyclists' performance levels. Male road cyclists, identified as the top amateur road cyclists of the cycling federations of 13 African countries, were subjected to a test battery for the measurement of lower-body flexibility, abdominal strength, peak and average anaerobic power output as well as maximum aerobic power. Practical significant differences between the successful and less successful road cyclists were found for almost all the Wingate related variables, some of the sub-maximum parameters, and most of the maximum physiological variables. Finally, the abdominal muscle strength test value, vertical jump distance, Wingate relative peak power, and respiratory compensation point expressed as percentage of V[Combining Dot Above]O2max and as relative power output were the physiological components that acted as adequate, accurate, and useful predictors of performance levels. Coaches and sport scientists should therefore include these components in testing protocols that are aimed at evaluating and improving cyclists' physical conditioning program
Heart rate variability and recovery as predictors of elite, African, male badminton players’ performance levels
No full textThe aim of this study was to determine whether pre-match, in-match, resting and post-match heart rate variability (HRV) as well as resting and post-match heart rate recovery (HRR) can serve as significant predictors of male, elite, African, singles badminton players’ performance levels. Twenty-two male badminton players were categorised into successful and less successful player groups according to match results. Heart rates were recorded every second before (pre-match), during (in-match) and directly after (post-match) 46 matches to determine 14 HRV and 2 HRR indices. Binary, forward, stepwise logistic regression analyses’ results showed that log transformed low frequency to high frequency ratio (Ln-LFnu/Ln-HFnu ratio) and peak very low frequency power (VLF power (Hz)), were significantly (p < .05) related to group allocation of successful and less successful badminton players. Overall model fit was good and 75% of players could be classified into their original groups by making use of the HRV-based logistic regression formulas. Furthermore, all models had a large effect in predicting player classification, although only the pre- and in-match models emerged as being useful. In conclusion, short-term frequency domain-related HRV variables are related to badminton match performances and should be considered when measuring HRV in sport and exercise settin
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