Allometric Scaling of Force-velocity Test Output Among Pre-pubertal Basketball Players.

Basketball is characterized by high-intensity episodes predominantly reliant on anaerobic metabolism. The force-velocity test enables individual determination of an optimal braking force and emerged as appropriate to estimate optimal peak power. It has rarely been used in youth basketball. This study aimed to examine the contribution of body size, composition, and biological maturation to interindividual variation in force-velocity test output among pre-pubertal basketball players. The sample consisted of 64 male participants (8.4-12.3 years). Stature, sitting height, body mass and two skinfolds were measured, and leg length estimated. Fat-free mass and lower limb volume were estimated from anthropometry. Age at peak height velocity was predicted from maturity offset. Optimal peak power was correlated with all body size descriptors (correlation: 0.541-0.700). Simple allometric models explained 30-47% of inter-individual variance, with fat-free mass being the best predictor of performance. Whole-body fat-free mass (as a surrogate for active muscle mass) plus the indicator of maturation emerged as the best proportional allometric model (53% explained variance). Even at pre-pubertal ages, the interpretation of the force-velocity test requires assessing the metabolically active component of body mass.

Effects of Plyometric Versus Optimum Power Load Training on Components of Physical Fitness in Young Male Soccer Players.

PURPOSE: The current study aimed to compare the effects of plyometric (PT) versus optimum power load (OPL) training on physical performance of young high-level soccer players. METHODS: Athletes were randomly divided into PT (horizontal and vertical drills) and OPL (squat + hip thrust exercises at the load of maximum power output) interventions, applied over 7 weeks during the in-season period. Squat and countermovement jumps, maximal sprint (10 and 30 m), and change of direction (COD; agility t test) were the pretraining and posttraining measured performance variables. Magnitude-based inference was used for within- and between-group comparisons. RESULTS: OPL training induced moderate improvements in vertical squat jump (effect size [ES]: 0.97; 90% confidence interval [CI], 0.32-1.61) and countermovement jump (ES: 1.02; 90% CI, 0.46-1.57), 30-m sprint speed (ES: 1.02; 90% CI, 0.09-1.95), and COD performance (ES: 0.93; 90% CI, 0.50-1.36). After PT training method, vertical squat jump (ES: 1.08; 90% CI, 0.66-1.51) and countermovement jump (ES: 0.62; 90% CI, 0.18-1.06) were moderately increased, while small enhancements were noticed for 30-m sprint speed (ES: 0.21; 90% CI, -0.02 to 0.45) and COD performance (ES: 0.53; 90% CI, 0.24-0.81). The 10-m sprint speed possibly increased after PT intervention (small ES: 0.25; 90% CI, -0.05 to 0.54), but no substantial change (small ES: 0.36; 90% CI, -0.40 to 1.13) was noticed in OPL. For between-group analyses, the COD ability and 30-m sprint performances were possibly (small ES: 0.30; 90% CI, -0.20 to 0.81; Δ = +1.88%) and likely (moderate ES: 0.81; 90% CI, -0.16 to 1.78; Δ = +2.38%) more improved in the OPL than in the PT intervention, respectively. CONCLUSIONS: The 2 different training programs improved physical performance outcomes during the in-season period. However, the combination of vertically and horizontally based training exercises (squat + hip thrust) at optimum power zone led to superior gains in COD and 30-m linear sprint performances.

Comparação da qualidade de vida entre atletas e paratletas brasileiros de alto rendimento / Comparison of the quality of life among high performance Brazilian athletes and parathletes

O objetivo do estudo foi comparar as características antropométricas e produção de potência aeróbia (pico de velocidade no teste de Carminatti [PVT-CAR]) entre diferentes categorias e níveis maturacionais em atletas de futebol. Cinquenta e três atletas do sexo masculino participaram do estudo divididos entre as categorias sub-11 (n=17), sub-13 (n=16), sub-15 (n=11) e sub-17 (n=9), e realizaram duas visitas: a primeira consistiu em avaliações antropométricas com massa corporal, estatura e dobras cutâneas, e questionário do estado pubertário; e a segunda visita foi avaliada a produção de potência aeróbia realizada com um teste progressivo com 5 séries de corrida vai-e-vem de 12 segundos, com 6 segundos de repouso, até a exaustão voluntária. A distância inicial do teste foi de 15 metros, com aumentos de progressivos de 1 metro a cada série, a maior velocidade atingida no teste (km.h-1 ) foi determinada como máxima produção de potência aeróbia (PVT-CAR). Os resultados demonstraram que as variáveis idade, estatura, massa corporal e PVT-CAR se diferenciam entre as categorias, e estágios maturacionais (púberes e pós-púberes, comparado com pré-púberes) (p<0,05), quanto a gordura corporal, não houve diferença entre as categorias e estágios maturacionais, assim como FCMÁXT-CAR (p>0,05). Em conclusão, a idade cronológica e os estágios maturacionais exercem importante função em relação as variáveis antropométricas e potência aeróbia. Por fim, o PVT-CAR se apresenta como uma ferramenta útil para classificação de um grupo, visto que atletas maturados suportam maiores cargas de treino....(AU)

The aim study was compare anthropometric characteristics and power aerobic production (peak velocity in Carminatt's Test [PVT-CAR]) between differences categories and levels maturational in soccer athletes. Fifty-three male athletes divided between categories under-11 (n=17), under-13 (n=16),under-15 (n=11) and under-17 (n=9) and performed two visits; the first consisted in evaluation anthropometrics with body mass, height and skinfolds, and pubertal status questionnaire; the second visit was evaluated the aerobic power production realized as the progressive test with 5 series running shuttlerun in 12 seconds, with 6 second rest, until the voluntary exhaustion. The distance initial the test was of 15 meters, with progressives increases in 1 meters every series, the highest velocity reached in the test (km.h1) was determined as maximum yield of aerobic power (PVT-CAR). The results demostred that variables age,stature, body mass and PVT-CAR differentiate between categories, and maturational stages (pre-pubertal and pubertal, compared with post-pubertal) (P<0.05), how much the body fat, there was no differences between categories and levels maturational, as HRMÁX-TCAR (P>0.05). In conclusion, the chronological age and maturational stages exert important function on anthropometric variables and aerobic power. Finally,the PVT-CAR presents itself as an useful tool for classifying a group, since mature athletes support higher training loads...(AU)

Comparação das características antropométricas e da potência aeróbia de atletas de futebol em diferentes categorias e estágios maturacionais / Comparation of anthropometric characteristics and aerobic power of soccer athletes in different categories and maturational stages

O objetivo do estudo foi comparar as características antropométricas e produção de potência aeróbia (pico de velocidade no teste de Carminatti [PVT-CAR]) entre diferentes categorias e níveis maturacionais em atletas de futebol. Cinquenta e três atletas do sexo masculino participaram do estudo divididos entre as categorias sub-11 (n=17), sub-13 (n=16), sub-15 (n=11) e sub-17 (n=9), e realizaram duas visitas: a primeira consistiu em avaliações antropométricas com massa corporal, estatura e dobras cutâneas, e questionário do estado pubertário; e a segunda visita foi avaliada a produção de potência aeróbia realizada com um teste progressivo com 5 séries de corrida vai-e-vem de 12 segundos, com 6 segundos de repouso, até a exaustão voluntária. A distância inicial do teste foi de 15 metros, com aumentos de progressivos de 1 metro a cada série, a maior velocidade atingida no teste (km.h-1 ) foi determinada como máxima produção de potência aeróbia (PVT-CAR). Os resultados demonstraram que as variáveis idade, estatura, massa corporal e PVT-CAR se diferenciam entre as categorias, e estágios maturacionais (púberes e pós-púberes, comparado com pré-púberes) (p<0,05), quanto a gordura corporal, não houve diferença entre as categorias e estágios maturacionais, assim como FCMÁXT-CAR (p>0,05). Em conclusão, a idade cronológica e os estágios maturacionais exercem importante função em relação as variáveis antropométricas e potência aeróbia. Por fim, o PVT-CAR se apresenta como uma ferramenta útil para classificação de um grupo, visto que atletas maturados suportam maiores cargas de treino....(AU)

The aim study was compare anthropometric characteristics and power aerobic production (peak velocity in Carminatt's Test [PVT-CAR]) between differences categories and levels maturational in soccer athletes. Fifty-three male athletes divided between categories under-11 (n=17), under-13 (n=16), under-15 (n=11) and under-17 (n=9) and performed two visits; the first consisted in evaluation anthropometrics with body mass, height and skinfolds, and pubertal status questionnaire; the second visit was evaluated the aerobic power production realized as the progressive test with 5 series running shuttlerun in 12 seconds, with 6 second rest, until the voluntary exhaustion. The distance initial the test was of 15 meters, with progressives increases in 1 meters every series, the highest velocity reached in the test (km.h1) was determined as maximum yield of aerobic power (PVT-CAR). The results demostred that variables age, stature, body mass and PVT-CAR differentiate between categories, and maturational stages (pre-pubertal and pubertal, compared with post-pubertal) (P<0.05), how much the body fat, there was no differences between categories and levels maturational, as HRMÁX-TCAR (P>0.05). In conclusion, the chronological age and maturational stages exert important function on anthropometric variables and aerobic power. Finally, the PVT-CAR presents itself as an useful tool for classifying a group, since mature athletes support higher training loads....(AU)

Comparative Effects of Two Interval Shuttle-Run Training Modes on Physiological and Performance Adaptations in Female Professional Futsal Players.

Teixeira, AS, Arins, FB, De Lucas, RD, Carminatti, LJ, Dittrich, N, Nakamura, FY, and Guglielmo, LGA. Comparative effects of two interval shuttle-run training modes on physiological and performance adaptations in female professional futsal players. J Strength Cond Res 33(5): 1416-1428, 2019-The purpose of this study was to analyze the effects of 2 shuttle-run interval training (SRIT) models with 1 and 3 directional changes per running bout on the aerobic and anaerobic performances of elite female futsal players. Sixteen players competing in the Brazilian National Division League took part in the study. The training protocols consisted of shuttle-run intervals organized in 4 sets of 4-minute bouts with 3 minutes of rest intervals between the sets. The SRIT models were composed of 1 (7.5 seconds running and 7.5 seconds pause [SRIT7.5×7.5]; n = 7) or 3 (15 seconds running and 15 seconds pause [SRIT15×15]; n = 9) directional changes. The athletes performed the following tests before and after a 5-week training period: incremental treadmill test (ITT), futsal intermittent endurance test (FIET) (with respective peak speeds [PSs]), and a repeated sprint ability (RSA) test. After the training period, PSFIET and speed at the second lactate turnpoint were very likely and almost certainly increased in both training regimens, respectively. SRIT15×15 induced possibly greater improvements in PSITT (+3.28%, 90% CL -0.16 to 6.82) and RSAmean (+1.17%, 90% CL -0.68 to 3.05) than SRIT7.5×7.5. In addition, SRIT15×15 resulted in a likely greater improvement in running economy (+4.33%, 90% CL -0.35 to 9.23) compared with SRIT7.5×7.5. In elite female futsal players, SRIT15×15 is a promising strategy to enhance performance-related physical fitness attributes in a short-term period (5 weeks) during the preseason, Because of its superior effects on these important aerobic and anaerobic qualities than a protocol with fewer directional changes.

Skeletal maturity and oxygen uptake in youth soccer controlling for concurrent size descriptors.

Interrelationships among skeletal maturity status, body size, ventilator thresholds (VT) and peak oxygen uptake (VO2peak) were considered in 47 adolescent male soccer players aged 12.5-15.4 years. Body mass, stature, and the triceps and subscapular skinfolds were measured. The latter were used to estimate fat mass and fat-free mass. Skeletal age was assessed with the Fels method. VO2peak and VO2 at the first (VT1) and second (VT2) ventilatory thresholds were determined during an incremental maximal exercise test on a motorized treadmill. Ratio standards and allometric models were used in the analysis. Scaling exponents suggested linearity for all combinations between size descriptors and physiological variables, except between log-transformed values of VT1 and body mass (mL·kg-0.801·min, 95%CI: 0.649 to 0.952). Early maturing players attained greater values than players classified as "on-time" in skeletal maturity for the three ventilatory parameters expressed in absolute terms (d ranged from 0.65 to 0.71). The differences were attenuated after normalizing for mass descriptors using ratio standards and scaled variables (d ranged from 0.00 to 0.31). The results suggested significant variability between maturity groups when moving from VT1 to maximal metabolic conditions expressed by unit of stature (VT1: t = -2.413, p = 0.02, d = 0.60; VT2: t = -2.488, p = 0.02, d = 0.65; VO2peak: t = -2.475, p = 0.02, d = 0.65). Skeletal maturity status and associated variation in overall body size affects VT1, VT2 and VO2peak. The observed scaling of ventilatory outputs for body size may be related to the better running economy and smaller body size of average maturing athletes.

Effect of Jump Interval Training on Kinematics of the Lower Limbs and Running Economy.

Ache-Dias, J, Pupo, JD, Dellagrana, RA, Teixeira, AS, Mochizuki, L, and Moro, ARP. Effect of jump interval training on kinematics of the lower limbs and running economy. J Strength Cond Res 32(2): 416-422, 2017-This study analyzed the effects of the addition of jump interval training (JIT) to continuous endurance training (40-minute running at 70% of peak aerobic velocity, 3 times per week for 4 weeks) on kinematic variables and running economy (RE) during submaximal constant-load running. Eighteen recreational runners, randomized into control group (CG) or experimental group (EG) performed the endurance training. In addition, the EG performed the JIT twice per week, which consisted of 4-6 bouts of continuous vertical jumping (30 seconds) with 5-minute intervals. The oxygen consumption (V[Combining Dot Above]O2) during the submaximal test (performed at 9 km·h) was similar before (EG: 38.48 ± 2.75 ml·kg·min; CG: 36.45 ± 2.70 ml·kg·min) and after training (EG: 37.42 ± 2.54 ml·kg·min; CG: 35.81 ± 3.10 ml·kg·min). No effect of training, group, or interaction (p > 0.05) was found for RE. There was no interaction or group effect for the kinematic variables (p > 0.05). Most of the kinematic variables had a training effect for both groups (support time [p ≤ 0.05]; step rate [SR; p ≤ 0.05]; and step length [SL; p ≤ 0.05]). In addition, according to the practical significance analysis (percentage chances of a better/trivial/worse effect), important effects in leg stiffness (73/25/2), vertical stiffness (73/25/2), SR (71/27/2), and SL (64/33/3) were found for the EG. No significant relationship between RE and stiffness were found for EG and CG. In conclusion, the results suggest that JIT induces important changes in the kinematics of the lower limbs of recreational runners, but the changes do not affect RE.

Efeito agudo da intensidade do exercício sobre as variáveis cardiorrespiratórias e metabólicas em jovens com excesso de peso / Acute effect of exercise intensity on the cardiorespiratory and metabolic variables in young with excess weight

O objetivo do trabalho foi comparar a resposta aguda das variáveis aeróbias durante o exercício intervalado de alta intensidade (EIAI) e o exercício contínuo moderado (ECONT) realizado por jovens com excesso de peso. Participaram do estudo 12 jovens (11,01 ± 1,82 anos; 69,09 ± 22,50kg; 154,43 ± 15,17; 28,27 ± 4,82kg/m2 ). Na primeira visita foi realizado um teste incremental máximo em cicloergômetro para determinação do consumo de oxigênio pico (VO2pico), potência pico e da frequência cardíaca pico (FCpico).Na segunda e terceira visitas foram realizados os protocolos de EIAI (10 repetições de 60s a 90% da potência pico para 60s de intervalo passivo) e ECONT (18 minutos contínuos a 50% da potência pico), ambos equalizados pelo trabalho total (kJ). Durante o EIAI e o ECONT, a FC e o consumo de oxigênio (VO2) foram continuamente mensurados. A concentração de lactato sanguíneo ([La]) foi determinada imediatamente após o término dos protocolos de exercício. Apesar da equalização do trabalho, os valores de FCpico (182 ± 3,34 vs 164 ± 3,34bpm), percentual do VO2pico (91 ± 2,00 vs. 76 ± 2,00 %), potência pico (105,0 ± 2,86 vs. 58,33 ± 2,86 W) e [La] (3,2 ± 0,12 vs. 1,8 ± 0,12 mmol.L-1 ) foram significantemente maiores no EIAI quando comparados ao ECONT. Concluímos que o EIAI resultou em maior estresse cardiovascular e metabólico comparado ao ECONT, refletido pelos valores de %VO2pico, FC e [La]. Por fim, destacamos a possibilidade do EIAI ser incorporado aos exercícios aeróbios de natureza contínua durante diferentes programas de atividade física praticada pelos jovens....(AU)

The aim of this study was to compare the acute response of aerobic variables during high intensity interval exercise (HIIE) and moderate continuous exercise (MCE) performed by obese adolescents. The study included 12 young (11.01 ± 1.82 years; 69.09 ± 22,50 kg; 154.43 ± 15.17cm; 28.27 ± 4.82 kg/m2 ). At the first visit was done a maximum incremental test on a cycle ergometer to determine the peak power and peak heart rate (HRpeak). At the second and third visits were conducted the EIAI (10 repetitions of 60s to 90% of peak power to 60s passive interval) and ECONT protocols (18 minutes continuously at 50% of peak power), both equalized by work (kJ). During HIIE and MCE, HR and oxygen consumption (VO2) were continuously measured. The blood lactate concentration ([La]) was determined immediately after the end of exercise protocols. Despite the equalization of work, HRpeak values (182 ± 3.34 vs 164 ± 3.34 bpm), percentage of VO2 peak (91 ± 2.00 vs. 2.00 ± 76%), power peak (105.0 ± 2.86 vs. 58.33 ± 2.86 W) and [La] (3.2 ± 1.8 vs. 0.12 ± 0.12 mmol.L-1 ) were significantly higher in HIIE compared to MCE. Concluded that HIIE results in an increase in cardiovascular and metabolic stress when VO2 peak, HR and [La]. Finally, we highlight the possibility to incorporate the HIIE in aerobic exercise continuous during different physical activity programs practiced by obese adolescents....(AU)

Effect of jumping interval training on neuromuscular and physiological parameters: a randomized controlled study.

This study analyzed the effect of 4 weeks of jumping interval training (JIT), included in endurance training, on neuromuscular and physiological parameters. Eighteen recreational runners, randomized in control and experimental groups, performed 40 min of running at 70% of velocity at peak oxygen uptake, for 3 times per week. Additionally, the experimental group performed the JIT twice per week, which consisted of 4 to 6 bouts of continuous vertical jumps (30 s) with 5-min intervals. Three days before and after the training period, the countermovement (CMJ) and continuous jump (CJ30), isokinetic and isometric evaluation of knee extensors/flexors, progressive maximal exercise, and submaximal constant-load exercise were performed. The JIT provoked improvement in neuromuscular performance, indicated by (i) increased jump height (4.7%; effect size (ES) = 0.99) and power output (≈ 3.7%; ES ≈ 0.82) of CMJ and rate of torque development of knee extensors in isometric contraction (29.5%; ES = 1.02); (ii) anaerobic power and capacity, represented by the mean of jump height (7.4%; ES = 0.8), and peak power output (PPO) (5.6%; ES = 0.73) of the first jumps of CJ30 and the mean of jump height (10.2%, ES = 1.04) and PPO (9.5%, ES = 1.1), considering all jumps of CJ30; and (iii) aerobic power and capacity, represented by peak oxygen uptake (9.1%, ES = 1.28), velocity at peak oxygen uptake (2.7%, ES = 1.11), and velocity corresponding to the onset of blood lactate accumulation (9.7%, ES = 1.23). These results suggest that the JIT included in traditional endurance training induces moderate to large effects on neuromuscular and physiological parameters.

Reliability and validity of the Carminatti's test for aerobic fitness in youth soccer players.

In this study, we examined the reliability and validity of peak velocity determined using the Carminatti's test (PVT-CAR) to evaluate the aerobic fitness of young soccer players (age = 13.4 ± 1.2 years; range, 10.3-15.4 years). To determine test-retest reliability of PVT-CAR, 34 adolescents (U-12, n = 13; U-14, n = 21) performed the Carminatti's test twice within 3-5 days. Validity was assessed in 43 adolescents (U-14, n = 20; U-16, n = 23) submitted to both the Carminatti's test and an incremental treadmill test to determine their aerobic fitness indicators. The intraclass correlation of PVT-CAR was 0.89, 0.93, and 0.81 with a coefficient of variation of 2.30% (0.33 km·h), 1.89% (0.26 km·h), and 2.66% (0.39 km·h) for the total sample (pooled data) or separately for the U-12 and U-14 groups, respectively. No significant difference was found between PVT-CAR and maximal aerobic speed (MAS) for the total sample (pooled data) or separately for the U-14 and U-16 groups. In addition, Bland and Altman plots evidenced acceptable agreement between them. The PVT-CAR was significantly related with peak velocity and MAS obtained in the incremental test for the total sample (r = 0.86 and 0.81, p < 0.01, respectively) and separately for the U-14 (r = 0.84 and 0.75, p < 0.01, respectively) and U-16 groups (r = 0.60 and 0.58, p < 0.01, respectively). Furthermore, the PVT-CAR was correlated with the V[Combining Dot Above]O2peak (r = 0.57, p < 0.01) and the velocity associated to the second ventilatory threshold (r = 0.69, p < 0.01) when the data were pooled (total sample). As a result, the Carminatti's test may be considered as a reliable and valid measure for assessing and monitoring the development of MAS of young soccer players during adolescence.