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This study investigated the effects of match location, quality of opposition (classified into: strong [1st to 4th position]; intermediate [5th to 15th position]; weak [16th to 20th position]), and match outcome on the match running performance of starters and non-starters from a top elite Brazilian soccer team. Absolute measures were calculated using total distance, high-speed (19.8-25.2 km·h-1), sprinting (≥ 25.2 km·h-1), total distance high-acceleration (> 2m·s2), and deceleration (< -2m·s2) were recorded by GPS units from a sample of young soccer players (N = 25) in a total of 17 matches. Relative measures were calculated by dividing absolute measures by the total duration of the matches. Non-starters covered greater total distance (p = 0.02), sprinting (p = 0.02), high-acceleration and deceleration (p = 0.04), sprinting distance relative per minute played (p = 0.005), and high-acceleration and deceleration relative per minute played (p < 0.001) when the team plays at home, strong opponents, and wins the matches. Starters covered greater total distance in high-speed running (p = 0.04), high-acceleration and deceleration (p = 0.03), and high-speed running relative per minute played (p = 0.04) when the team plays strong opponents and wins the matches. These findings highlight the impact of contextual factors during matches on the locomotor performance of young soccer players.

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The aim of this study was to analyse the load-velocity and load-power relationships in the free-weight back-squat (BSQ) and hexagonal bar deadlift (HBD) exercises. Twenty-five (n = 25) resistance-trained men (age = 23.7 ± 2.8 years) performed a progressive load test at maximal intended velocity to determine their BSQ and HBD one-repetition maximum (1RM). Mean propulsive velocity (MPV) during the concentric phase of the lift was recorded through a linear encoder. Load-velocity and load-power relationships were analysed by fitting linear regression and the second-order polynomial, respectively, to the data. Maximum strength (1RM), MPV (30-80% 1RM), and power output (30-90% 1RM) were higher for HBD compared to BSQ exercise (p < 0.05). A very strong relationship between MPV and relative intensity was found for both BSQ (R2 = 0.963) and HBD (R2 = 0.967) exercises. The load that maximizes power output (Pmax) was 64.6 ± 2.9% (BSQ) and 59.6 ± 1.1% (HBD) 1RM. There was a range of loads at which power output was not different than Pmax (BSQ: 40-80% 1RM; HBD: 50-70% 1RM). In conclusion, the load-velocity and load-power relationships might assist strength and conditioning coaches to monitor and prescribe exercise intensity in the BSQ and HBD exercises using the velocity-based training approach.

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We examined the effects of different small-sided games (SSG) configurations on heart rate (HR), rating of perceived exertion (RPE), and running demands in soccer players. Twelve male soccer players (U18) participated in this randomized cross-over study. Players performed three SSG in different "fixed" and "dynamic" pitch sizes (3v3 in large (SSGL) and small (SSGS) fixed area; or 3v3 in dynamic dimensions [SSGD]), with 4x4 minutes interspersed by 2 minutes of rest. HR measures (maximum [HRmax], average [HRavg], and percentage of maximum [%HRmax]), RPE, and running demands were collected across the SGG sessions. The following running activities were recorded: total distance covered (TD), distance covered (DC) at 6-12 km·h-1, ≥ 12-18 km·h-1, and >18 km·h-1, peak running speed, acceleration (ACC) and deceleration (DEC) at 1-2 m·s-2 and 2-3 m·s-2, player load, and high metabolic load distance (HMLD). SSGL displayed higher HRavg, %HRmax, and RPE values than SSGS (p < 0.05). SSGL resulted in higher TD, DC at 6-12 km·h-1, ≥ 12-18 km·h-1, > 18 km·h-1, and higher peak speed than SSGS and SSGD (p < 0.05). Moreover, SSGD presented higher TD and DC at 6-12 km·h-1 and ≥ 12-18 km·h-1 than SSGS (p < 0.05). In contrast, SSGD and SSGS showed higher number of ACC and DEC at 1-2 m·s-2 than SSGL (p < 0.05). In conclusion, the pitch size and playing area of the SSG can be manipulated to promote desired physiological and physical demands in young soccer players.HighlightsWe examined how fixed (small and large) or variable (dynamic) pitch sizes affected the psychophysiological and running demands of young soccer players during small-sided games.Small-sided games with larger pitch sizes and areas per player elicited greater psychophysiological and running demands than small areas.The pitch size designed in the current study does not appear to affect the number of acceleration and deceleration (> 2 m·s-2).Varying the pitch size during the small-sided games (i.e. dynamic condition) could be an interesting constraint to be considered by soccer coaches in order to enhance task variability.

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This study aimed to analyze the effect of playing videogames and using social media applications on smartphones on decision-making and countermovement jump (CMJ) performance in amateur boxers. Twenty one boxers were enrolled in the study and were randomly assigned to all three experimental conditions [smartphone (30SMA), videogame (30VID), and control (CON)]. CMJ was measured before and 30-min after each experimental condition. The athletes ran simulated combat recorded for decision-making analysis. The boxers watched coaching videos (CON), used social media applications on smartphones (30SMA), and played video games (30VID) for 30 min just before the combat simulation. Both attack and defense decision-making performance were worse in both 30SMA and 30VID conditions compared to the CON condition (p = 0.001). Regarding CMJ, despite no condition effect (p = 0.96) been obtained, a time effect (p = 0.001) was observed; So, it was found a decrease in CMJ performance after all experimental conditions (p = 0.001), with no difference between them. Using social media applications on smartphones and playing video game impairs decision-making performance in amateur boxers, with no harms for CMJ performance.

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The purpose of this study was to investigate the effects of three simulated goalball games on neuromuscular, physiological, perceptual, and technical parameters. Ten male players underwent assessments before and immediately after each game. Heart rate was recorded at rest and during all games that were entirely filmed for further technical performance analysis. Exercise significantly decreased knee extensor muscles peak force and percentage of voluntary activation after the second and third games, indicating the presence of central fatigue. Heart rate responses remained predominantly in a range equivalent to moderate activity intensity in all games. In addition, perceptual parameters were associated with reduced frequency of throws and density of actions. These findings suggest significant implications for the management of physical training, game strategy during a competition, and fixture change from three to two games per day.

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This study aimed to verify the effects of congested fixture and matches' participation on internal and external workload indexes in professional Brazilian soccer players. Rate of perceived exertion-based training load (sRPE), distance- and accelerometry-based measures were daily monitored over 119 training sessions and 33 matches performed by 29 male outfield players. Weeks were classified as congested (n = 11, two or more matches within a 7-day period) and regular (n = 10, one match or less within a 7-day period). The players were divided based on the matches' participation: (1) players who played ≥ 60 min (G1); (2) players who played < 60 min (G2); (3) players who did not participate of the match (G3). The findings showed that independent of the levels of participation during the matches, regular weeks presented greater acute, monotony, and strain indices for internal and external workload measures than congested weeks. The G1 presented the highest values for most of the workload indices in both regular and congested weeks, except for monotony indices (internal and external load) that G2 showed greater values than G1 and G3. Coaches and practitioners should plan the training "doses" to reduce disparities of these different match's participation and congested schedule weeks.

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COVID-19 pandemic, has led to several countries adopting the use of masks in public spaces. Mask used during physical exercise it may induce early fatigue. However, despite the results with aerobic exercise, as far as we know, no studies have been carried out on wearing a mask during resistance exercise.This randomized, crossover study verified the acute effect of an FFP2/N95 face mask on moderate- and high-load upper body resistance exercise performance in recreational weight lifters.The FFP2/N95 face mask impacted performance, evaluated with bar velocity, in the high-intensity resistance bench press exercise until movement failure but decreased oxygen saturation and increased rate of perceived effort only in the moderate-intensity exercise.

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The purpose is to analyze the effect of social networks on smartphones before and during velocity-based resistance exercise on the internal training load, heart rate variability (HRV), and cognitive interference control. Twelve trained adults volunteered to participate in this randomized and crossover design research study with three experimental conditions. The participants randomly performed a resistance exercise session, watching TV before (CON) the session or using social networks on a smartphone prior to (30SMA-P) and intra-session (SMA-INT). The participants underwent sets with repetitions [15RM load] up to 20% mean velocity loss. HRV indicators and cognitive interference control were measured before and 30-min after each experimental session. Internal training load was evaluated 30-min after each experimental session, which was calculated by the product between resistance exercise volume and RPE. No condition versus time interaction for HRV indicators (p > 0.05) was observed. It was not revealed a condition versus time interaction for cognitive interference control (p > 0.05). No condition effect for internal training load (p > 0.05) was observed. It was concluded that 30-min of social networks on smartphones before or intra-session resistance exercise had no effects on HRV indicators, cognitive interference control, and internal training load in trained adults.

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Considering the role of autonomic nerve activity in blood pressure control, this study aimed to investigate the cardiac autonomic nerve responses after an aerobic exercise session in Anabolic Androgenic Steroids (AAS) users. Twenty men (AAS, n = 9; control group, n = 11) performed an aerobic exercise session (60 min, 70 to 80% of HRmax). Heart rate variability (HRV) was assessed before and during a 60-min post-exercise recovery period. RMSSD (root mean square successive difference of the RR intervals) and the LF/HF ratio (low frequency/high frequency spectra) were also evaluated. The Student's t-test for independent samples was used to compare differences between initial group characteristics. Repeated measures ANOVA was used to compare pre- and post-exercise HRV recovery (p < 0.05). AAS had a lower SDNN (standard deviation of the intervals) (40.8 ± 16.8 vs. 71.6 ± 24.7 ms; p = 0.04, d = 1.4) and a higher LF/HF (3.4 ± 2.1 vs. 1.8 ± 0.9%; p = 0.03, d = 0.9) before exercise. AAS and controls had similar RMSSD (14.0 ± 15.8 vs. 18.9 ± 12.1 ms; p = 0.20) and a LF/HF (2.8 ± 1.6 vs. 2.4 ± 1.2 ms; p = 0.41) immediately post-exercise. The between-groups comparison revealed a higher HF/LF at 30 min (4.3 ± 1.4 vs. 2.5 ± 1.3%; p = 0.008, d = 1.3) and 60 min (5.0 ± 2.2 vs. 2.3 ± 0.8%; p = 0.001, d = 1.6) for the AAS group in the recovery time. This study demonstrated impaired parasympathetic activity at rest and immediately after the exercise session as an adverse effect of AAS usage, but similar behavior regarding the restoration of sympathetic activity.

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This study aimed to examine the acute physiological effect of shuttle-run-based high-intensity intermittent exercise (HIIE) performed at the same relative speed (i. e., 100% PST-CAR) on sand (SAND) and grass (GRASS) in male junior soccer players. Seven Under-23 Brazilian national league ("Série A") soccer players completed four testing sessions in either SAND or GRASS surface condition. The first two testing sessions consisted of performing a maximal progressive shuttle-run field protocol until volitional exhaustion (Carminatti's test, T-CAR), whereas the third and fourth sessions comprised a HIIE session on each ground surface. The HIIE session consisted of three 5-min bouts [12 s shuttle-run (with a direction change every 6 s)/12 s of passive rest] performed at 100% of T-CAR peak speed (PST-CAR) with 3 min of passive recovery between sets. Measurements of oxygen uptake (VO2), heart rate (HR), blood lactate concentration ([La]), and rating of perceived exertion (RPE) were performed during all conditions. The SAND condition elicited significantly higher %VO2peak (94.58 ± 2.73 vs. 87.45 ± 3.31%, p < 0.001, d = 2.35), %HRpeak (93.89 ± 2.63 vs. 90.31 ± 2.87%, p < 0.001, d = 1.30), RPE (8.00 ± 0.91 vs. 4.95 ± 1.23 a.u., p < 0.001, d = 2.82), and [La] (10.76 ± 2.37 vs. 5.48 ± 1.13 mmol/L, p < 0.010, d = 2.84). This study showed that higher internal workloads are experienced by the players during a single HIIE session performed on a softer surface as SAND, even when the exercise intensity was individualized based on 100%PST-CAR.