Effects of a Short-Term Detraining Period on the Strength Deficit and Functional Performance of Highly Trained Soccer Players.

ABSTRACT: Loturco, I, Grazioli, R, Veeck, F, Nakamura, FY, Inácio, M, Schons, P, Preissler, A, Pinto, RS, Pereira, LA, McGuigan, MR, and Cadore, EL. Effects of a short-term detraining period on the strength deficit and functional performance of highly trained soccer players. J Strength Cond Res 37(10): 2058-2063, 2023-The aim of this study was to examine the effects of a 4-week detraining period on the neuromuscular performance of highly trained soccer players. Pre and post detraining, 18 adult soccer players (age: 27 ± 4.9 years; height: 180.2 ± 7.1 cm; body mass [BM]: 78.9 ± 7.6 kg) performed vertical jumps, 20-m linear sprints, curve sprint and change of direction speed tests, and a progressive loading test in the half-squat exercise with loads corresponding to 50, 100, and 150% of the players' BM to assess the peak-force (PF), mean power (MP), and strength-deficit (SDef). Pre and post differences in the variables of interest were analyzed using paired t -tests and effect sizes (ES). No significant changes were detected for vertical jumping height and sprint times. Higher PF at 50 and 100% BM and lower SDef were shown when comparing pre- and postassessments (ES = 0.66, 0.68, 0.55; p = 0.018, 0.016, and 0.046, respectively). The MP at 50 and 100% BM increased significantly after the detraining phase (ES = 0.56, 0.82; p = 0.049 and 0.007, respectively). The results indicate that these athletes were able to maintain and achieve satisfactory levels of performance after a short period of training cessation. Interestingly, some strength- and power-derived parameters improved significantly after short-term detraining, which may have important implications for training programs aimed at maximizing speed and power performance. It is recommended that coaches test their players not only at the beginning but also at the end of the season, to better evaluate variations in performance and thus create more efficient and tailored training strategies.

External Loads of Elite Soccer Referees: A Systematic Review with meta-analysis.

The objective of the present study was to describe the total and fragmented external loads, at different intensities, of soccer referees in European and South American competitions during official matches through a systematic review and meta-analysis of cross-sectional studies. A systematic review was conducted in April, 2020. In all, 32 studies were included, incorporating 578 referees evaluated in 3170 games through video analysis or a global positioning system. Regarding external loads, it was observed that the total average distance covered by the referees was 10,461.74 m, with running speeds predominantly below 13 km.h-1. The total distance covered by the referees in the European competitions was higher and more intense than that of the referees in the South American tournaments, being 11,187.02 m and 9319.61 m, respectively. We suggest that referees' training can be organized according to the distances found at different intensities, in which low-intensity races can be performed below 13 km.h-1 with distances of approximately 4500 m, while high-intensity training can be developed with speeds from 18 to 24 km.h-1 for approximately 800 m. In addition, planning must consider the competition characteristics.

Mathematical models to identify high-performance players for the Brazilian under-19 men's volleyball team.

The objective of this study was to identify parameters that best discriminate between selected and non-selected players for the Brazilian under-19 men's volleyball team and propose mathematical models to identify high-performance players. To this end, 18 selected (16.89±0.96 years) and 138 non-selected (16.91±0.74 years) players for the under-19 team were assessed for the training profile, anthropometric profile, and physical performance level. The discriminant function analysis was used to build the models, with a significance of α<0.05. The spike jump reach showed a greater correlation with the discriminant scores obtained in the two models (r=0.701; r=0.782). The 10 variables included in Model 1 helped identify 88.9% of the players selected in their group of origin; Model 2 - obtained by the spike jump reach and duration of playing experience - identified 83.3% of the players selected. Therefore, coaches should be aware that differences between the selected and non-selected players are multi-factorial, with the spike jump reach being the most relevant assessment factor. Furthermore, good players for the selection can be identified using the two models: Model 1 promises greater success with ten assessments, whereas Model 2 allows the identification of suitable players for the under-19 men's volleyball team with only two simple assessments.

Correlations between linear sprint with the ball, linear sprint without the ball, and change-of-direction without the ball in professional female soccer players.

The evolution of female soccer is related to the increase in high-intensity actions and choosing the abilities that best characterize the players' performance. Determining the capabilities that best describe the players' performance becomes essential for coaches and technical staff to obtain the results more efficiently within the competitive calendar. Thus, the study aimed to analyze the correlations between performance in the 20-m sprint tests with and without the ball and the Zigzag 20-m change-of-direction (COD) test without the ball in professional female soccer players. Thirty-three high-level professional female soccer players performed the 20-m sprint tests without a ball, 20-m sprint tests with the ball, and the Zigzag 20-m COD test without the ball. The shortest time obtained in the three trials was used for each test. The fastest time in the three trials was used for each test to calculate the average test speed. The Pearson product-moment correlation test was applied to analyze the correlation between the performance in the tests. Pearson's product-moment correlation test was used to analyze the correlation between the performance in the trials, with a significance level of α < 0.05. The average speed in the 20-m sprint tests with ball showed very large and significant correlations with the speed in the Zigzag 20-m COD test (r = 0.822; p < 0.001; 95% CI = 0.666 to 0.909). The 20-m sprint tests with ball and 20-m sprint tests without ball showed moderate, positive and significant correlation (r = 0.363; p = 0.038; 95% CI = 0.023-0.628). The tests of 20-m sprint tests without ball and Zigzag 20-m COD test also showed moderate, positive and significant correlation (r = 0.415; p = 0.016; 95% CI = 0.084-0.664). The female-female soccer players with a better ability to change direction may also have a better technical ability to drive the ball at high speed. However, they will not necessarily be the fastest in the linear sprint without the ball. Coaches and technical staff may choose to perform tests seeking efficiency and practicality, especially in a congested competitive period.

A comparison of the internal and external load demands imposed on professional soccer referees in FIFA's current model of physical test in relation to games.

BACKGROUND: Based on the need to investigate the demands imposed on referees in the current model of physical evaluation and during professional games, this study's objective was to compare these demands in the physical test versus the games. METHODS: Thus, it evaluated the heart rate, distance covered, time, and speed of all 14 referees in the physical test and during Brazil's first division state championship games using a Global Positioning System enabled heart rate monitor. RESULTS: The maximum heart rate (HRmax) and maximum speed were higher in the physical test (183.86±12.79 bpm) and (26.80±0.96 km/h), respectively, than in the games (170.25±17.71 bpm) (P=0.008) and (24.27±1.68 km/h) (P=0.001), respectively. In the HRmax zone ≥90 and ≤100%, the time and percentage distance were greater in the physical test (47.87±16.60% and 58.57±22.78%), respectively, than in the games (17.82±18.29% and 18.84±18.92%, respectively; P<0.001). However, in the speed zone <13 km/h, the time and the percentage distance were longer in the game (93.73±1.26% and 86.13±2.31%), respectively, than in the physical test (68.73±12.31% and 39.65±9.74%, respectively; P<0.001). CONCLUSIONS: Thus, it is concluded that the professional referees perform at greater intensities during the physical test than in the games. In contrast, the demands for intensities corresponding to aerobic metabolism are greater in games or equal to those in physical testing, depending on the intensity reference.

The relationship between height of vertical jumps, functionality and fall episodes in patients with chronic obstructive pulmonary disease: A case-control study.

This study aimed to compare the height of jumps and functional parameters in patients with chronic obstructive pulmonary disease (COPD) to those in healthy people, in addition to assessing the relationship among variables in patients with COPD. Twenty patients with COPD (forced expiratory volume [FEV1] % of predicted: 39.98 ± 11.69%; age: 62.95 ± 8.06 years) and 16 healthy people (FEV1% of predicted: 97.44 ± 14.45%; age: 59.94 ± 6.43 years) were evaluated, and all participants performed the Squat Jump (SJ) and Counter Movement Jump (CMJ) tests to assess rapid force considering the jumping height. Functional capacity was assessed using the self-selected walking speed tests, walking speed in 10 m, walking test in 6 min, balance on one leg, sitting and standing, timed up and go, and a stair-climbing test. In addition, the questionnaires on recall of falls, Falls Efficacy Scale-International (concern with falling), International Physical Activity Questionnaires, and Saint George Respiratory Questionnaire were administered. The height of the jumps showed no difference between the groups, but the COPD group performed worse in most functional tests and was more afraid of falling. The number of falls was correlated with height in the SJ (r = -0.51) and CMJ (r = -0.62) jumps (p < 0.05), and with the performance in different functional tests. We suggest that interventions targeting rapid force may bring improvements in functional mobility and physical fitness as well as reducing fall episodes in patients with COPD.

Short and long-term effects of water-based aerobic and concurrent training on cardiorespiratory capacity and strength of older women.

Studies show that, in the short term, water-based aerobic training (WAT) promotes the same strength gains as water-based concurrent training (WCT). In addition, it is known that some training progression strategy must be employed after the first weeks of training in order to continue stimulating neuromuscular gains. The aim of this paper was to compare the effects of three water-based training on cardiorespiratory capacity and strength of older women in short and long-terms. Fifty-seven participants were randomized into the groups: 1) aerobic training (AT); 2) concurrent training whose resistance training progressed to the use of resistive equipment (CTRE); and 3) concurrent training whose resistance training progressed to multiple sets (CTMS). Participants trained twice a week for 16 weeks. An incremental treadmill test and the one-repetition maximal test of knee extensors were performed before and after 8 and 16 weeks. Peak oxygen consumption showed similar increases from pre to post-16 weeks (AT: 9%, CTRE: 11%, CTMS: 5%). Oxygen consumption at the second ventilatory threshold and strength were increased from pre to post-8 weeks (AT: 15%, CTRE: 16%, CTMS: 3% and AT: 9%, CTRE: 5%, CTMS: 9%, respectively) and from post-8 to post-16 weeks (AT: 6%, CTRE: 3%, CTMS: 12% and AT: 4%, CTRE: 8%, CTMS: 4%, respectively). In conclusion, the three training programs promoted similar increases in the cardiorespiratory capacity and WAT promoted similar strength gains as WCT in short and long terms. Moreover, the use of resistive equipment and the increase in the number of sets are effective progression strategies.

Continuous and interval aerobic sessions: effects on triglyceride concentrations / Sessões aeróbicas intervaladas e contínuas: efeitos sobre as concentrações de triglicerídeos

The regular practice of physical exercise, primarily aerobic, has been recommended as a component of the non-pharmacological treatment for dyslipidemias. However, there is a lack of studies in the literature comparing the acute effects of different aerobic exercise models (continuous and interval) on triglycerides concentrations.The purpose of the present study was to analyze the magnitude of change on triglycerides concentrations after a single session of interval and continuous exercise in persons with dyslipidemia. This study was a randomized crossover clinical trial. Fifteen volunteers performed two different aerobic sessions, a continuous and an interval session. The intensity of the continuous session was maintained between 85-90% of the heart rate at anaerobic threshold (HRAT). The interval session consisted of 9 sets of 4 minutes at 85-90%HRAT followed by one minute below 85%HRAT. Triglycerides concentrations were assessed before, immediately after and at the end of 30 minutes after all sessions. Both sessions models resulted in alterations in triglycerides concentrations immediately after exercise (p = 0.005), without difference between them (p = 0.446). Continuous session increased triglycerides concentrations by 34.9% from pre-exercise to immediately post-exercise and the interval session, by 7.9%. Thirty minutes after exercise, triglyceride concentrations showed no significant difference in relation to the pre-exercise and immediately after exercise moments in both session models. Therefore,it is concluded that aerobic exercise promotes responses in triglycerides concentrations of dyslipidemic patients, independently of the exercise method, either continuous or interval

A prática regular de exercício físico, principalmente aeróbico, tem sido recomendado como componente de tratamento não farmacológico contra as dislipidemias. No entanto, a literatura carece de estudos comparando os efeitos agudos de diferentes modelos de exercício aeróbico (contínuo e intervalado) sobre as concentrações de triglicerídeos. O objetivo do presente estudo foi analisar a magnitude de mudança sobre as concentrações de triglicerídeos após uma sessão de exercício intervalado e contínuo em pessoas com dislipidemia. Além disto, este estudo se caracteriza por ser um ensaio clínico randomizado cruzado. Nele, quinze voluntários realizaram duas sessões aeróbicas diferentes, uma sessão contínua e outra intervalada. A intensidade da sessão contínua se manteve entre 85-90% da frequência cardíaca referente ao limiar anaeróbico (HRAT). A sessão intervalada consistiu de 9 séries de quatro minutos entre 85-90% da HRAT seguidas de um minuto abaixo de 85% da HRAT. As concentrações de triglicerídeos eram verificadas antes, imediatamente após e passados 30 minutos do término de todas as sessões. Ambos os modelos de sessões resultaram em alterações das concentrações de triglicerídeos imediatamente após exercício (p = 0,005), sem diferença entre elas (p = 0,446). A sessão contínua aumentou as concentrações de triglicerídeos em 43,9% do pré-exercício para imediatamente após o exercício e a sessão intervalada aumentou em 7,93% no mesmo período. Trinta minutos após o exercício, as concentrações de triglicerídeos não apresentaram diferença significativa em relação aos momentos pré-exercício e imediatamente após o exercício em ambos os modelos de sessão. Assim, conclui-se que o exercício aeróbico promove alterações nas concentrações de triglicerídeos de pacientes dislipidêmicos, independentemente do método de exercício, se contínuo ou intervalado

Heart rate deflection point as an alternative to determining the anaerobic threshold in dyslipidaemic patients

Aim: The aim of the present study was to verify the agreement between the ventilatory method (VT) and the alternative method of heart rate deflection point (HRDP) in determining the anaerobic threshold (AT) during incremental treadmill test in dyslipidaemic patients. Methods: Twenty-seven dyslipidaemic patients (61.50 ± 10.46 years) performed an incremental treadmill test, in which the AT was determined using both methods. Bland-Altman statistics was adopted in order to verify the agreement between the methods. Results: Agreement in AT determination between the VT and HRDP methods was observed (p < 0.05) for heart rate (138.00 ± 23.80 and 136.26 ± 22.18 bpm, respectively), oxygen uptake (31.00 ± 10.33 and 31.00 ± 11.17 ml.kg−1.min−1), and treadmill velocity (7.67 ± 1.71 km.h-1and 8.00 ± 1.75 km.h-1). Conclusion: Our results suggest that the HRDP method can be adopted for the determination of the AT in dyslipidaemic patients, showing agreement with the VT method.(AU)