The purpose of this monitoring study was to investigate how alterations in training affect changes in force-related characteristics and weightlifting performance. Subjects: Seven competitive weightlifters participated in the study. Methods: The weightlifters performed a block style periodized plan across 20 weeks. Force plate data from the isometric mid-thigh pull and static jumps with 0 kg, 11 kg, and 20 kg were collected near the end of each training block (weeks 1, 6, 10, 13, 17, and 20). Weightlifting performance was measured at weeks 0, 7, 11, and 20. Results: Very strong correlations were noted between weightlifting performances and isometric rate of force development (RFD), isometric peak force (PF), peak power (PP), and jump height (JH). Men responded in a more predictable manner than the women. During periods of higher training volume, RFD was depressed to a greater extent than PF. JH at 20 kg responded in a manner reflecting the expected fatigue response more so than JH at 0 kg and 11 kg. Conclusions: PF appears to have been more resistant to volume alterations than RFD and JH at 20 kg. RFD and JH at 20 kg appear to be superior monitoring metrics due to their “sensitivity.”

No description available.

Lower body explosive power (LBEP) forms a critical component in any individual and team sport performance and it is therefore essential to develop a means of predicting LBEP in adolescents for early identification of future talent in various sporting codes. LBEP is frequently used by athletes during matches or competitions where explosive movements such as jumping, agility running and sprinting are required for successful performance. These movements are usually found in individual sports such as long jump and high jump as well as in team sports such as basketball, volleyball and soccer. To date not much literature is available on LBEP, especially with regard to LBEP prediction models. Furthermore, studies on adolescents are scarce and a LBEP prediction model has not yet been developed for a South African adolescent population. It is against this background that the objectives of this study were firstly, to develop a LBEP prediction model from various physical and motor performance components among a cohort of adolescents living in the Tlokwe local municipality of Dr Kenneth Kaunda district in the North-West Province, South Africa; and secondly, to develop a LBEP prediction model from several anthropometric measurements among a cohort of male and female adolescents living in the Tlokwe local municipality of Dr Kenneth Kaunda district in the North-West Province, South Africa. Two hundred and fourteen (15.8±0.68 years) 15-year-old adolescents (126 females, 88 males) from 6 surrounding schools within the Tlokwe local municipality of Dr Kenneth Kaunda district in the North-West Province of South Africa were purposefully selected from pre-acquired class lists took part in the study. Data was collected by means of various questionnaires as well as anthropometrical, physical and motor performance tests. For representation of LBEP a principal component factor analysis was done and the results indicated that the vertical jump test (VJT) was the best indicator of LBEP in the cohort of adolescents. With regard to the anthropometrical related LBEP prediction model, the forward stepwise regression analysis yielded a correlation coefficient of R2 = 0.69. The following variables contributed significantly (p≤0.001) to the anthropometrical LBEP prediction model: stature (57%), muscle mass percentage (10%) and maturity age (3%). The LBEP prediction model that was developed equated to LBEP (vertical jump) = -136.30 + 0.84(stature) + 0.7(muscle mass percentage) + 4.6(maturity age). Variables other than the variables that formed part of the study could explain the further 31% variance in the LBEP of the adolescents. The physical and motor performance LBEP prediction model indicated that gender (39%) and 10 m speed (7%) contributed significantly (p ≤ 0.001) to the overall prediction of the LBEP of the adolescents. The LBEP prediction model delivered a stepwise forward regression analysis coefficient of R2=0.458 and a prediction formula LBEP = 68.21 + 9.82 (gender) – 18.33(10 m speed). The remaining 56% of the variance in the results could be explained by other factors than the variables considered in the study. In conclusion, to the best of the researchers’ knowledge, this is the first study which has made an attempt at developing LBEP prediction models from the anthropometrical, physical and motor performance components of a cohort of adolescents of South Africa. The prediction models developed in the study will assist teachers sport scientists and sporting coaches who have limited resources available, to measure and calculate LBEP in adolescents, with the means to do so in South Africa. Further high quality studies are necessary to further improve and develop such prediction models for various age groups of adolescents in the greater South Africa. / MSc (Sport Science), North-West University, Potchefstroom Campus, 2014

Lower body explosive power (LBEP) forms a critical component in any individual and team sport performance and it is therefore essential to develop a means of predicting LBEP in adolescents for early identification of future talent in various sporting codes. LBEP is frequently used by athletes during matches or competitions where explosive movements such as jumping, agility running and sprinting are required for successful performance. These movements are usually found in individual sports such as long jump and high jump as well as in team sports such as basketball, volleyball and soccer. To date not much literature is available on LBEP, especially with regard to LBEP prediction models. Furthermore, studies on adolescents are scarce and a LBEP prediction model has not yet been developed for a South African adolescent population. It is against this background that the objectives of this study were firstly, to develop a LBEP prediction model from various physical and motor performance components among a cohort of adolescents living in the Tlokwe local municipality of Dr Kenneth Kaunda district in the North-West Province, South Africa; and secondly, to develop a LBEP prediction model from several anthropometric measurements among a cohort of male and female adolescents living in the Tlokwe local municipality of Dr Kenneth Kaunda district in the North-West Province, South Africa. Two hundred and fourteen (15.8±0.68 years) 15-year-old adolescents (126 females, 88 males) from 6 surrounding schools within the Tlokwe local municipality of Dr Kenneth Kaunda district in the North-West Province of South Africa were purposefully selected from pre-acquired class lists took part in the study. Data was collected by means of various questionnaires as well as anthropometrical, physical and motor performance tests. For representation of LBEP a principal component factor analysis was done and the results indicated that the vertical jump test (VJT) was the best indicator of LBEP in the cohort of adolescents. With regard to the anthropometrical related LBEP prediction model, the forward stepwise regression analysis yielded a correlation coefficient of R2 = 0.69. The following variables contributed significantly (p≤0.001) to the anthropometrical LBEP prediction model: stature (57%), muscle mass percentage (10%) and maturity age (3%). The LBEP prediction model that was developed equated to LBEP (vertical jump) = -136.30 + 0.84(stature) + 0.7(muscle mass percentage) + 4.6(maturity age). Variables other than the variables that formed part of the study could explain the further 31% variance in the LBEP of the adolescents. The physical and motor performance LBEP prediction model indicated that gender (39%) and 10 m speed (7%) contributed significantly (p ≤ 0.001) to the overall prediction of the LBEP of the adolescents. The LBEP prediction model delivered a stepwise forward regression analysis coefficient of R2=0.458 and a prediction formula LBEP = 68.21 + 9.82 (gender) – 18.33(10 m speed). The remaining 56% of the variance in the results could be explained by other factors than the variables considered in the study. In conclusion, to the best of the researchers’ knowledge, this is the first study which has made an attempt at developing LBEP prediction models from the anthropometrical, physical and motor performance components of a cohort of adolescents of South Africa. The prediction models developed in the study will assist teachers sport scientists and sporting coaches who have limited resources available, to measure and calculate LBEP in adolescents, with the means to do so in South Africa. Further high quality studies are necessary to further improve and develop such prediction models for various age groups of adolescents in the greater South Africa. / MSc (Sport Science), North-West University, Potchefstroom Campus, 2014

O presente estudo teve como objetivo monitorar parâmetros subjetivos: Carga Interna de Treinamento (CIT) e Escala de Qualidade Total da Recuperação (TQR) e objetivos: (cortisol, testosterona e razão T:C) na primeira fase da temporada competitiva, composta por 8 semanas, comparando semanas com duas ou apenas uma partida por semana, em atletas profissionais de Voleibol. Quatorze jogadores profissionais de voleibol participaram da investigação. As variáveis dependentes foram avaliadas durante as 8 primeiras semanas da SuperLiga Masculina de Voleibol, afim de estabelecer a comparação entre semanas com duas partidas e semanas com uma única partida. A CIT foi calculada por semana, pelo método da PSE da sessão, bem como, o índice de monotonia. O escore da TQR e as amostras salivares (analisadas por ELISA) foram coletados semanalmente sempre no primeiro dia útil da semana. Além disso, foi avaliado o desempenho do salto contra movimento (CMJ). Os principais resultados da presente investigação são: o comportamento da CIT refletiu o planejamento da CET. As semanas 2, 3, 7 e 8 (duas partidas por semana) apresentaram maior magnitude de CIT ~6000 UA e as semanas 1, 4, 5 e 6 (uma partida por semana) com menor magnitude de CIT ~4500; o escore da escala TQR sofreu maior redução nas semanas 2, 3, 7 e 8 (duas partidas por semana, apresentando escore de ~6,7 UA) em comparação as semanas 1, 4, 5, 6 (uma partida por semana) que apresentaram escore de ~7,8); as respostas hormonais, testosterona e cortisol, não apresentaram diferenças entre as semanas com uma ou duas partidas disputadas; a maior magnitude das correlações entre as respostas endócrinas e a CIT foi observada nos períodos com duas partidas; foi observado aumento do salto vertical após o período de investigação (TE = 0,30); a associação entre a menor variabilidade semanal na escala de recuperação e melhora do salto. Este estudo revela que o planejamento da CET foi acompanhado pelo comportamento da CIT durante atemporada competitiva, sendo que as semanas com duas partidas apresentaram maior CIT em comparação às semanas com apenas uma partida disputada, que, por sua vez, apresentaram menor CIT. O escore da escala TQR apresentou maior redução nas semanas com duas partidas em comparação às semanas com apenas uma partida. Os hormônios cortisol e testosterona não apresentaram alteração ao longo das 8 semanas de investigação. As correlações entre as variáveis do presente estudo apresentaram maior magnitude nos períodos de maior CET, reforçando a hipótese que em períodos de maior CET, há maior sensibilidade dos parâmetros subjetivos. Por fim, o planejamento adotado, durante as 8 primeiras semanas do período competitivo, foi eficaz para promover aumento do CMJ em jogadores profissionais de voleibol. Os atletas que apresentam a menor variabilidade semanal no escore da TQR apresentaram o maior aumento do CMJ. Esses resultados reforçam a relevância da adoção estratégias de monitoramento integrado, utilizando parâmetros objetivos e subjetivos. Esse constante acompanhamento pode fornecer informações valiosas sobre a forma que os atletas lidam com as demandas da temporada competitiva, auxiliando a retro-alimentação do planejamento da CET ao longo do processo / The current study aimed to monitor subjective parameters: Internal Training Load (ITL) and Total Recovery Quality Scale (TQR) and objectives parameters: (cortisol, testosterone and T: C ratio) during the first phase of the competitive season, comparing weeks with two or only one match per week in professional volleyball players. Fourteen professional volleyball players participated of research. The dependent variables were evaluated during the first 8 weeks of the Men\'s Volleyball SuperLiga, to compare the weeks with 2 matches and the weeks with a single match. ITL was calculated per week by the session RPE method, as well as, the monotony index. The TQR score and the salivary samples (analyzed by ELISA) were collected weekly on the first day of the week. In addition, the performance of the counter movement jump (CMJ) was evaluated. The main results of the present investigation are: ITL reflected the ETL planned. Weeks 2, 3, 7 and 8 (2 matches per week) with a higher magnitude of CIT ~ 6000 AU and weeks 1, 4, 5 and 6 (one match per week) with a lower magnitude of CIT ~ 4500; the TQR score had a greater reduction at weeks 2, 3, 7 and 8 (2 matches per week, presenting a score of ~6.7 AU) compared to weeks 1, 4, 5, 6 (one match per week) presenting a score of ~ 7.8); the endocrine responses did not show differences between the weeks with 2 or 1 matches played; the greater magnitude of the correlations between the endocrine responses and the ITL was observed in weeks with 2 matches; there was an increase in CMJ after the investigation period and (Effect Size = 0,30); the association between the lower weekly variability in the recovery scale (TQR) and the improvement in the CMJ. This study reveals that the ETL planning was accompanied by the ITL during the competitive season, and the weeks with 2 matches had a higher ITL compared to the weeks with only 1 match played, which, in turn, presented lower ITL. The TQR score showed a greater reduction in the weeks with 2 matches compared to the weeks with only 1 match played, following the ITL behavior. The hormonal responses were not affected during the 8 weeks of investigation, withoutdifference between the weeks with 2 or 1 match disputed. The correlations between the variables of this research showed greater magnitude in weeks of higher ETL (2 matches), reinforcing the hypothesis that in periods of higher ETL, there is greater sensitivity of the subjective parameters. Finally, the ETL periodization adopted, during the first 8 weeks of the competitive period, was effective to promote increase of CMJ in professional players of volleyball. The athletes with the lowest weekly variability in the TQR score had the highest increase in CMJ. These results reinforce the relevance of adopting integrated monitoring strategies, using objective and subjective parameters. This constant monitoring can provide valuable insight into how athletes cope with the demands of the competitive season, provinding feed-back for the ETL planning throughout the process

Syftet med denna studie var att analysera vilken del av försäsongsträningens två cykler som påverkade styrka och explosivitet i nedre extremitet, accelerationsförmåga, agility och anaerob uthållighet genom att sammanställa dessa egenskaper hos kvinnliga elitfotbollsspelare, för att därefter kunna utvärdera om försäsongsträningen förbättrade dessa egenskaper. Tester som kunnat påvisa viktiga och avgörande fysiska kvalitéer hos elitfotbollsspelarevaldes ut och dessa genomfördes vid tre tillfällen; före, under och efter försäsongsträningen. Testerna var; knäböj, vertikalhopp, 15 m sprint, T-test och YO-YO Intermittent Återhämtningstest (YO-YO IÅ).Studien innefattade 24 damfotbollsspelare på elitnivå från alla spelarpositioner. Till den andra testomgången observerades en signifikant förbättring av styrka, agility och anaerob uthållighet. Vid de andra testerna observerades ingen skillnad. Första delen av försäsongsträningen utvecklade till viss del spelarna åt rätt håll genom en förbättring av styrkan i nedre extremiteten. Den signifikanta förbättringen i agility och anaerob uthållighet kom lite för tidigt, det vill säga under den första cykeln avförsäsongsträningen, vilket hade varit mer önskvärt efter den andra cykeln. Detta innebär attandra viktiga egenskaper kan ha försummats. / The purpose of this study was to analyze which part of the pre-season trainings two cycles that affected strength and power in lower extremities, acceleration, agility and anaerobic endurance by compiling these abilities of a female elite soccer player team, and then evaluate whether the pre-season training improved these abilities. Tests that could prove important and crucial physical qualities in elite soccer players were selected and then performed on three occasions; before, during and after the pre-seasontraining. The selected tests were; squat, vertical jump, 15 m sprint, T-test and YO-YO Intermittent Recovery Test (YO-YO IR). The study included 24 female elite soccer playersfrom all playing positions. A significant improvement in strength, agility and anaerobic endurance were measured in the second test round. In the other tests there were no difference observed. The first cycle of the pre-season training partly developed the players in the right direction, which the significant improvement in strength revealed. The significant improvement in the agility and anaerobic endurance occurred a little too early, it would have been more beneficial after the second cycle. This means that other important qualities might have been neglected.

Abstract Introduction In order to evaluate aerobic, power and strength abilities coaches typically has performed all the physical tests at the same testing session. Today there is a lack of instruments tested for reliability in that kind of setting. Aim The purpose of this study was to investigate intra-session reliability for countermovement jump (CMJ) and Isometric Midthigh Pull (IMTP) after a fatiguing cycle-ergometer VO2-maxtest. Method: A quantitative, descriptive, cross-sectional study design where 25 Swedish elite athletes, 11 women (age 26.9 ± 8.3 year, weight 63.3 ± 7.4 kg, length 169.8 ± 7.4 cm and BMI 21.9 ± 1.4) and 14 men (age 23.4 ± 2.9 year, weight 77.9 ± 12.4 kg, length 179.0 ± 8.3 cm and BMI 24.2 ± 2.0), from different sports were recruited through a stratified comfort selection from the initial survey study within the project: Relative Energy Deficit in Swedish Athletes (the REI-project). The study-participants performed physical testing in one test session, the test-protocol consisted of a incremental VO2-max cycle-ergometer test to fatigue followed by 3 attempts CMJ and 3 attempts IMTP. Results The relative reliability was excellent for both CMJ and IMTP (Intraclass correlation (ICC) 0,948 and 0,983 respectively), not surprisingly due to the heterogeneous population.  The absolute reliability was excellent as well (percentage of typical Error (TE%) 5,84 and 4,02, percentage of coefficient of variation (CV%) 6,81 and 7,63 respectively). Conclusion The CMJ and IMTP are intra-session reliable in measuring jump hight and isometric strength in a state of fatigue. / Abstrakt Introduktion I syfte att utvärdera såväl aerob kapacitet, spänst och styrka utför tränare ofta dessa fysiska tester vid ett och samma testtillfälle. Idag saknas det testinstrument som reliabilitetstestats i en sådan kontext.Syfte Avsikten med denna studie var att undersöka intra-session reliabiliteten i Countermovement Jump (CMJ) och Isometriskt Mid Thigh Pull (IMTP) utförda efter ett utmattande cykelergometertest för VO2-max. Metod En kvantitativ, deskriptiv, tvärsnittsstudie valdes där 25 svenska elitidrottare, 11 kvinnor (ålder 26.9 ± 8.3 år, vikt 63.3 ± 7.4 kg, längd 169.8 ± 7.4 cm and BMI 21.9 ± 1.4) och 14 män (ålder 23.4 ± 2.9 år, vikt 77.9 ± 12.4 kg, längd 179.0 ± 8.3 cm and BMI 24.2 ± 2.0), inom olika idrotter rekryterades genom ett stratifierat bekvämlighetsurval från projektet Relativ energibrist i svensk idrott (REI-projektet) initiala enkätstudie. Forskningspersonerna utförde fysiska tester vid ett tillfälle, testprotokollet bestod av ett stegrat VO2-max cykelergometertest till utmattning följt av 3 maximala försök CMJ och 3 maximala försök IMTP. Resultat Relativ reliabilitet visades utmärkt för både CMJ och IMTP (intraclass correlation (ICC) 0,948 respektive 0,983), vilket inte var förvånande med tanke på den heterogena populationen. Absolut reliabilitet visades även den vara utmärkt (typfel uttryckt i procent (TE%) 5,84 respektive 4,02 och variationskoefficient uttryckt i procent (CV%) 6,81 respektive 7,63). Slutsats CMJ och IMTP är reliabla testinstrument, intra-session, för mätning av hopphöjd och isometrisk styrka i ett utmattat tillstånd. / Projekt: Relativ energibrist i svensk idrott (REI-projektet)