Maximal Shuttle Run Test Research Articles

Effects of 3days of citrulline malate supplementation on short-duration repeated sprint running performance in male team sport athletes.

Citrulline malate (CM) is purported to be an ergogenic aid during various types of exercise performance. However, the effects of CM on repeated sprint performance (RSP) are under-explored. In a placebo-controlled, double-blind, counterbalanced cross-over design, male university-level team sport athletes (n=13) performed two familiarization trials, after which CM or placebo (PLA) (8×1g tablets each day) were taken on the 2days prior to, and with breakfast on the morning of, each main experimental trial. The main experimental trials employed a RSP protocol consisting of 10 repetitions of 40m maximal shuttle run test (MST) with a 30s interval between the start of each sprint. Sprint times and heart rate were recorded throughout the MST, and blood lactate concentrations were measured before, immediately after, and 5min after completing the MST. CM resulted in better RSP compared to PLA, as indicated by a lower sprint performance decrement (Sdec: CM, 4.68%±1.82% vs. PLA, 6.10%±1.83%; p=0.03; ES=0.77), which was possibly influenced by the fastest sprint time being faster in CM (CM, 8.16±0.34s vs. PLA, 8.29±0.39s; p=0.011; ES=0.34). There were no differences between CM and PLA in average sprint time (p=0.54), slowest sprint time (p=0.48), blood lactate concentrations (p=0.73) or heart rate (p=0.18), nor was there a condition×time interaction effect across the 10 sprints (p=0.166). Three days of CM supplementation (8g daily) attenuated the sprint performance decrement during short-duration high-intensity exercise in the form of running RSP in male university-level team sport athletes.

Physical capacities related to running performance during simulated matches in young futsal players

This study aimed to verify the relationship between physical capacities and distance covered during simulated matches in young futsal players. Sixteen under-19 male futsal players of regional level (age 18.1 ± 0.96 years, body mass 67.4 ± 9.7 kg, height 176 ± 5 cm) participated in this study. Players performed the futsal intermittent endurance test (FIET), maximal shuttle run test (MST), squat jump and countermovement jump tests. Two simulated futsal matches were performed to assess the distance covered at different intensities. Pearson correlation and multiple linear regression were used for statistical analysis. The main results showed significant correlation of peak velocity obtained in the FIET (PVFIET) (15.8 ± 0.6 km h−1) with distance covered per minute (r = 0.85, p < 0.01) and distance covered at high intensity (r = 0.60, p = 0.03). Fatigue index (5.6 ± 1.9%) correlated with the distance covered at high intensity (r = − 0.70, p = 0.01) and percentage of distance covered in sprint (r = − 0.69, p = 0.01). The PVFIET and best time in the MST (8.48 ± 0.38 s) explained 50% of the variance in the total distance covered; whereas, the PVFIET explained 73% of the distance covered per minute. The fatigue index was a negative predictor of high-intensity running and explained 40% of its variance. PVFIET is one of the most important variables capable of predicting physical futsal match-related performance. Moreover, the capacity to resist fatigue during repeated sprints and the maximal sprinting speed of players were related to high-intensity running performance during the matches.

The Relation of Physical Activity, Sedentary Behaviors, and Academic Achievement Is Mediated by Fitness and Bedtime.

This study investigated the associations of subjectively and objectively measured physical activity (PA) and sedentary behavior with academic achievement. We further examined whether aerobic fitness, obesity, and bedtime mediate these associations. This study included 970 children aged 9-15years (52.3% girls) from 9 schools throughout Finland. Register-based academic achievement [grade point average (GPA)] as well as self-reported and accelerometer-measured PA/sedentary behavior were assessed during spring 2013. Aerobic fitness (assessed via a maximal shuttle run test), body composition (assessed via bioimpedance analysis), and self-reported bedtime were collected. Structural equation modeling was applied to examine the associations. Standardized regression coefficients are presented. Self-reported PA had a direct positive [β = 0.084; 95% confidence interval (CI), 0.023 to 0.145] and an indirect positive association with GPA through higher aerobic fitness (β = 0.061; 95% CI, 0.033 to -0.087). Accelerometer-based PA was not associated with GPA. Self-reported screen time had an indirect negative association with GPA through later bedtime (β = -0.071; 95% CI, -0.096 to -0.035) and lower aerobic fitness (β = -0.039; 95% CI, -0.059 to 0.019). Nonscreen sedentary time had a direct positive (β = 0.193; 95% CI, 0.101 to -0.289) and an indirect negative association with GPA through lower aerobic fitness (β = -0.040; 95% CI, -0.063 to -0.016). Participating in PA, avoiding excessive screen time, and going to bed earlier may benefit academic achievement.

Acute effects of aerobic, resistance and concurrent exercises, and maximal shuttle run test on coagulation and fibrinolytic activity in healthy young non-athletes.

The present study aimed to differentiate the acute effects of aerobic, resistance and concurrent exercises, and 40-meter maximal shuttle run test (MSRT) on coagulation and fibrinolysis in non-athletic healthy young men. Fifty participants (aged 20-30 years old) were randomly divided into a control and four exercise groups: aerobic, resistance, concurrent, and MSRT (N.=10 each). A single session of exercise was performed: the aerobic group used a cycle ergometer (60% heart rate maximum) for 40 minutes, the resistance group performed 3 movements for the upper extremities and 3 movements for the lower extremities with 60% of 1-repetition maximum (each movement in 2 sets of 8-10 repetitions), the concurrent group followed by a combination of aerobic and resistance protocols, and the MSRT group performed four trials of the 40-meter MSRT. The duration for aerobic, resistance and concurrent exercises was 60 minutes, while it was only 30 minutes for MSRT. Before and 30 minutes after exercise, blood samples were collected to evaluate fibrinogen (mg/dL), D-dimer (mg/dL), prothrombin time (PT), partial thromboplastin time (PTT) and platelet count (×103/µL). There was a significant reduction in fibrinogen in all exercise groups compared to before exercise (P<0.01) and to the control group (P<0.05). D-dimer, as the index of fibrinolysis, was significantly increased in all exercise groups compared to before exercise (P<0.01) and to the control group (P<0.05). Aerobic exercise and MSRT also increased the PT and PTT (P<0.001). Finally, the number of platelets had a significant reduction following resistance and concurrent exercise protocols (P<0.001, P<0.01). Based on our findings, both coagulation and fibrinolytic activity are strongly affected by single a session of different exercise protocols.