Nuell, S, Illera-Domínguez, V, Carmona, G, Macadam, P, Lloret, M, Padullés, JM, Alomar, X, and Cadefau, JA. Hamstring muscle volume as an indicator of sprint performance. J Strength Cond Res 35(4): ...902-909, 2021-This study aimed to compare mechanical properties and performance during sprinting, as well as thigh muscle volumes (MVs), between national-level sprinters and physically active males. In addition, the relationships between thigh MVs and sprint mechanical properties and performance were investigated. Seven male sprinters and 9 actives performed maximal-effort 40-m sprints. Instantaneous velocity was measured by radar to obtain theoretical maximum force (F0), the theoretical maximum velocity (V0), and the maximum power (Pmax). For MV assessment, series of cross-sectional images of each subject's thigh were obtained by magnetic resonance imaging for each of the quadriceps and hamstring muscles and the adductor muscle group. Sprinters were faster over 10 m (7%, effect size ES = 2.12, p < 0.01) and 40 m (11%, ES = 3.68, p < 0.01), with significantly higher V0 (20%, ES = 4.53, p < 0.01) and Pmax (28%, ES = 3.04, p < 0.01). Sprinters had larger quadriceps (14%, ES = 1.12, p < 0.05), adductors (23%, ES = 1.33, p < 0.05), and hamstrings (32%, ES = 2.11, p < 0.01) MVs than actives. Hamstrings MV correlated strongly with 40-m sprint time (r = -0.670, p < 0.01) and V0 (r = 0.757, p < 0.01), and moderately with Pmax (r = 0.559, p < 0.05). Sprinters were significantly faster and had greater V0 and Pmax than active males. Larger MVs were found in sprinters' thighs, especially in the hamstring musculature, and strong correlations were found between hamstring MV and sprint mechanical properties and sprint performance.
PURPOSE This study aimed to investigate the correlation between repeated sprint ability (RSA) and Hoff test performance in high school soccer players. METHODS Fourteen male high school football ...players participated in this study. After measuring body composition, the Bangsbo Sprint Test for RSA and Hoff test were performed. The tests were conducted in the field to create an experimental environment similar to that during actual training and competition. RESULTS A significant correlation was observed between the fatigue index (FI) in the RSA and running distance in the Hoff test (p<.05). A high level of correlation between the performance distance and body fat percentage and muscle mass in the Hoff test was observed (p<.001). There was no significant relationship between the best and average RSA records using the Hoff test. CONCLUSIONS It was confirmed that the running distance in the Hoff test developed for event specificity affects the FI in RSA. In subsequent studies, it will be necessary to examine the variables affecting the best and average RSA records.
On-ice skating sprint performance is a significant predictor and requirement for playing at the highest levels of hockey. The purpose of this study was to determine the relationship between maximum ...and dynamic strength measures and on-ice sprint performance in university level ice hockey athletes. Both male (n=18) and female (n=13) hockey players participated in this study. The off-ice measures included two assessment procedures utilizing a force plate; an isometric mid-thigh pull (IMTP) to assess maximum strength and a countermovement jump (CMJ) to assess dynamic strength. Both off-ice measures were analyzed from both a relative (CMJr and IMTPr) and absolute (CMJa and IMTPa) perspective. The on-ice measures were 7.71m and 15.42m sprint times. Pearson product moment correlations were used to quantify the relationships between variables. CMJa (r = -0.56 to -0.61), IMTPa (r = -0.65 to -0.67) and IMTPr (r = -0.55) were significantly correlated (p < 0.05) with on-ice sprint performance. When analyzed by sex, no significant relationships (p > 0.05) were observed between CMJ measures and on-ice sprint times. No significant relationships (p > 0.05) were observed between IMTP measures and on-ice sprint times when individually analyzing male participants, while significant relationships (p < 0.05) were observed in females between IMTPa (r = -0.70 to -0.71) and IMTPr (r = -0.68 to -0.71) and on-ice sprint times. It is concluded that both maximum and dynamic strength are important factors in on-ice sprint performance in hockey players. Furthermore, maximum strength seems to be an important characteristic in on-ice sprint ability in females.
O futsal é o esporte de quadra mais praticado no Brasil, suas principais ações são expressas por atividades motoras envolvendo alta intensidade e curta duração (correr, saltar, chutar e etc.) com ...ênfase principalmente nas capacidades físicas força e velocidade. Ambas as capacidades são importantes para o melhor desempenho desses movimentos, diante disto, a avaliação destas é fundamental para nortear o treinamento dos atletas. Objetivo: Correlacionar o desempenho de saltos verticais e sprints em jogadores de futsal da categoria sub-11. Materiais e Métodos: A amostra foi composta por 17 jogadores de futsal da categoria sub 11, os quais foram submetidos à anamnese, avaliação da composição corporal e testes de salto agachado (SA) e salto com contramovimento (SCM) e sprints em linha reta (SLR) e sprint com mudança de direção (SMD). A normalidade dos dados foi verificada pelo teste de Shapiro-Wilk. Para análise das correlações foi utilizado o teste de correlação de Pearson. Resultados: Foi encontrada correlação alta, significativa e negativa entre SA e os SLR 0-10m (r= -0,69) e SMD 12,5-25m (r= -0,60), e entre o SCM e os SLR 0-10m (r= -0,75), SLR 0-20m (r= -0,58) e SMD12,5-25m (r= -0,57). Conclusão: A correlação encontrada foi alta, negativa e significativa entre o SV e Sprints em jogadores de futsal da categoria sub 11 indicando que as tarefas apresentam fatores em comum e que o treinamento de força, por meio dos SV, parece ser efetivo no desempenho da velocidade. Palavras-chave: Futsal. Salto vertical. Sprint. Correlation between performance of vertical jumps and sprints in Futsal players in the sub-11 category Futsal is the most practiced court sport in Brazil, its main actions are expressed by motor activities involving high intensity and short duration (running, jumping, kicking, etc.) with emphasis mainly in strength and speed physical capacities. Both capacities are important for the better performance of these movements, therefore, the evaluation is fundamental to guide the training of the athletes. Objective: Correlate the performance of the vertical jumps and sprint in futsal players of the under-11 category. Materials and Methods: The sample was composed by 17 futsal players of the under-11 category, that where submitted to anamnesis, evaluation of the body composition and jump tests (SJ and CMJ) and sprints (SLS and SCD). The normality of the data was verified by the Shapiro-Wilk test. For the analysis of the correlations was utilized the Pearson correlation test. Results: It was founded high, negative and significant correlation between SJ and SLS 0-10m (r= -0,69) and SCD 12,5-25m (r= -0,60), and between the CMJ and the SLS 0-20m (r= -0,58) and SCD 12,5-25m (r= -0,57). Conclusion: The results show that the training aiming to improve the performance of jumps may contribute to the development of the capacity of sprints in futsal players of the under-11 category. Key words: Futsal. Vertical jump. Sprint.
We investigated the effects of far‐infrared radiation (FIR) lamp therapy on changes in muscle damage and performance parameters following six sets of 15‐min Loughborough intermittent shuttle test ...(LIST), a simulated soccer match. Twenty‐four elite female soccer players (20–24 y) were assigned into FIR or sham treatment group (n = 12/group). The participants received a 60‐min FIR or sham treatment (30 min per muscle) over knee extensors (KE) and flexors (KF) at 2, 25, 49, 73, and 97 h post‐LIST. Maximal voluntary isometric contraction (MVC) torque and muscle soreness of the KE and KF, plasma creatine kinase (CK) activity as muscle damage markers, and several performance parameters including countermovement jump (CMJ) and Yo‐Yo intermittent recovery test level 1 (YYIR1) were measured before and 1, 24, 48, 72, 96, and 120 h post‐LIST. Changes in the measures were compared between groups by a mixed‐design two‐way ANOVA. The running distance covered during LIST and changes in the measures at 1‐h post‐LIST (before the treatment) were similar (p = 0.118–0.371) between groups. Changes in muscle damage markers at 24–120 h post‐LIST were smaller (p < 0.05, η2 = 0.208–0.467) for the FIR (e.g., MVC‐KE torque decrease at 48‐h post‐LIST: −1 ± 2%, peak KE soreness: 16 ± 10 mm, peak CK: 172 ± 42 IU/L) than sham group (−11 ± 9%, 33 ± 7 mm, 466 ± 220 IU/L, respectively). Performance parameters recovered faster (p < 0.05, η2 = 0.142–0.308) to baseline for the FIR (e.g., decreases at 48‐h post‐LIST; CMJ: 0 ± 1%, YYIR1: 0 ± 1%) than sham group (−6 ± 2%, −9 ± 6%, respectively). These results suggest that the FIR lamp therapy was effective for enhancing recovery from a soccer match.
Recent literature supports the importance of horizontal ground reaction force (GRF) production for sprint acceleration performance. Modeling and clinical studies have shown that the hip extensors are ...very likely contributors to sprint acceleration performance. We experimentally tested the role of the hip extensors in horizontal GRF production during short, maximal, treadmill sprint accelerations. Torque capabilities of the knee and hip extensors and flexors were assessed using an isokinetic dynamometer in 14 males familiar with sprint running. Then, during 6-s sprints on an instrumented motorized treadmill, horizontal and vertical GRF were synchronized with electromyographic (EMG) activity of the vastus lateralis, rectus femoris, biceps femoris, and gluteus maximus averaged over the first half of support, entire support, entire swing and end-of-swing phases. No significant correlations were found between isokinetic or EMG variables and horizontal GRF. Multiple linear regression analysis showed a significant relationship (P = 0.024) between horizontal GRF and the combination of biceps femoris EMG activity during the end of the swing and the knee flexors eccentric peak torque. In conclusion, subjects who produced the greatest amount of horizontal force were both able to highly activate their hamstring muscles just before ground contact and present high eccentric hamstring peak torque capability.
PURPOSE This study aimed to investigate the effect of dynamic warm-up (DW), including DW and self-myofascial release (SMFR), on soft tissue stiffness and exercise performance. METHODS Eight adult men ...participated in this study. The procedure was conducted twice every 2 weeks. Soft tissue stiffness measurements and exercise performance were performed as a pre-post-test. DW only and DW with SMFR were performed as an exercise intervention for the two groups, respectively. RESULTS In the group conducted solely by DW, the stiffness of the gastrocnemius and rectus femoris muscles increased (p<.05), and in the DW group including SMFR, the stiffness of the rectus femoris muscle (p<.01) and biceps femoris muscle increased (p<.05). The Achilles and patellar tendon showed no significant changes in either group. A significant increase was observed in both the DW group and the DW group containing SMFR in the 30 m sprint (p<.01). The vertical jump (VJ) showed no significant change in both groups. CONCLUSIONS Therefore, DW, including DW with SMFR, increased muscle stiffness, specifically through a 30-m sprint. In a follow-up study, it is considered necessary to investigate the effect of the VJ through the development of a DW program that changes the stiffness of tendons.
Unlike the short sprint, it is known that the body cannot complete the 400-m race at maximum effort, and sprinters need to utilize mechanical energy effectively to control fatigue during the race. ...The purpose of this study was to clarify the relationship between the effectiveness index (EI) of mechanical energy utilization (assessed by stride length divided by mechanical work) and 400-m sprint performance. Twelve collegiate sprinters ran the 400-m distance. EI was calculated from kinematic data at the 160-m and 360-m points. EI at the 160-m point was negatively correlated with the 400-m running time (r = − 0.797，p <0.01), whereas EI at the 360-m point was positively correlated (r = 0.836，p <0.001). EI at the 160-m point was positively correlated with the segment torque power (r = 0.614，p <−0.05) and hip flexion peak power (r = 0.588，p <0.05) during the forward swing. These results suggest that the key to improving 400-m sprint performance is to utilize mechanical energy effectively in the early phase and generate more mechanical energy in the late phase. Additionally, emphasizing thigh forward swing movements seems to be an effective means of utilizing mechanical energy in the early phase.
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