Purpose: The aim of the present study was to investigate whether street basketball organized as 3 v 3 on either a half court(HC) with 1 basket or a full court(FC) with 2 baskets could improve fitness and health profil...Purpose: The aim of the present study was to investigate whether street basketball organized as 3 v 3 on either a half court(HC) with 1 basket or a full court(FC) with 2 baskets could improve fitness and health profiles of untrained men after 3 months of supervised training.Methods: Thirty-five untrained men(aged 20—42 years) completed the pre-and post-intervention testing(FC: n = 13, HC: n = 12, CO(control):n = 10). The training attendance was 2.0 ± 0.4 and 1.9 ± 0.3 times per week in FC and HC, respectively. Mean heart rate(HR) was 83.8 ± 6.0 percent of maximal heart rate(%HR_(max)) and 84.5 ± 2.9 %HR_(max) in FC and HC, respectively.Results: The 3 months of street basketball training on an FC with 2 baskets increased maximal oxygen uptake(2.4 mL/min/kg(95% confidence interval(CI): 1.0—3.9)), time to exhaustion(47 s(95%CI: 26—67)), lean body mass(0.8 kg(95%CI: 0.1—1.5)), and bone mineral density(0.021 g/cm^2(95%CI: 0.011—0.031)), whereas mean arterial pressure(—5.6 mm Hg(95%CI: —7.5 to 3.7)), body fat percentage(—1.6%,(95%CI: —2.5 to —0.7)), heart rate(—18 bpm(95%CI: —24 to —12)), and blood lactate(median: —1.4 mmol/L(interquartile range: —1.5 to —0.6)) during submaximal running were lowered. The changes were less pronounced after the training period when playing on an HC with 1 basket, but increases in maximal oxygen uptake(1.6 mL/min/kg(95%CI: —0.1 to 3.3)), time to exhaustion(28 s(95%CI: 9—47)), lean body mass(1.3 kg(95%CI: 0.3—2.4)), and lower body fat percentage(—0.9%(95%CI: —1.9 to —0.1)) were observed in this group.Conclusion: Three months of 3 v 3 street basketball training improved fitness and led to broad-spectrum improvements in variables related to overall health profile, with the most marked effects observed when playing on an FC with 2 baskets.展开更多
Purpose: The aims of this study were to:(1) provide a comprehensive physiological profile of simulated basketball activity and(2) identify temporal changes in player responses in controlled settings.Methods: State-lev...Purpose: The aims of this study were to:(1) provide a comprehensive physiological profile of simulated basketball activity and(2) identify temporal changes in player responses in controlled settings.Methods: State-level male basketball players(n = 10) completed 4 × 10 min simulated quarters of basketball activity using a reliable and valid courtbased test. A range of physiological(ratings of perceived exertion, blood lactate concentration([BLa~—]), blood glucose concentration([BGlu]), heart rate(HR), and hydration) and physical(performance and fatigue indicators for sprint, circuit, and jump activity) measures were collected across testing.Results: Significantly reduced [BLa~—](6.19 ± 2.30 vs. 4.57 ± 2.33 mmol/L; p = 0.016) and [BGlu](6.91 ± 1.57 vs. 5.25 ± 0.81 mmol/L;p = 0.009) were evident in the second half. A mean HR of 180.1 ± 5.7 beats/min(90.8% ± 4.0% HR max) was observed, with a significant increase in vigorous activity(77%—95% HR max)(11.31 ± 6.91 vs. 13.50 ± 6.75 min; p = 0.024) and moderate decrease in near-maximal activity(>95% HR_(max))(7.24 ± 7.45 vs. 5.01 ± 7.20 min) in the second half. Small increases in performance times accompanied by a significantly lower circuit decrement(11.67% ± 5.55% vs. 7.30% ± 2.16%; p = 0.032) were apparent in the second half.Conclusion: These data indicate basketball activity imposes higher physiological demands than previously thought and temporal changes in responses might be due to adapted pacing strategies as well as fatigue-mediated mechanisms.展开更多
A new vision-based approach was presented for predicting the behavior of the ball carrier—shooting, passing and dribbling in basketball matches. It was proposed to recognize the ball carrier’s head pose by classifyi...A new vision-based approach was presented for predicting the behavior of the ball carrier—shooting, passing and dribbling in basketball matches. It was proposed to recognize the ball carrier’s head pose by classifying its yaw angle to determine his vision range and the court situation of the sportsman within his vision range can be further learned. In basketball match videos characterized by cluttered background, fast motion of the sportsmen and low resolution of their head images, and the covariance descriptor, were adopted to fuse multiple visual features of the head region, which can be seen as a point on the Riemannian manifold and then mapped to the tangent space. Then, the classification of head yaw angle was directly completed in this space through the trained multiclass LogitBoost. In order to describe the court situation of all sportsmen within the ball carrier’s vision range, artificial potential field (APF)-based information was introduced. Finally, the behavior of the ball carrier—shooting, passing and dribbling, was predicted using radial basis function (RBF) neural network as the classifier. Experimental results show that the average prediction accuracy of the proposed method can reach 80% on the video recorded in basketball matches, which validates its effectiveness.展开更多
Background： The majority of injuries reported in female basketball players are ankle sprains and mechanisms leading to injury have been debated. Investigations into muscular imbalances in barefoot versus shod conditi...Background： The majority of injuries reported in female basketball players are ankle sprains and mechanisms leading to injury have been debated. Investigations into muscular imbalances in barefoot versus shod conditions and their relationship with injury severity have not been performed. The purpose of this study was to investigate the effects of wearing athletic shoes on muscular strength and its relationship to lower extremity injuries, specifically female basketball players due to the high incidence of ankle injuries in this population. Methods： During pre-season, 11 female collegiate basketball players underwent inversion and eversion muscle strength testing using an iso- kinetic dynamometer in both a barefoot and shod conditions. The difference between conditions was calculated for inversion and eversion peak torque, time to peak torque as well as eversion-to-inversion peak torque percent strength ratio for both conditions. Lower extremity injuries were documented and ranked in severity. The ranked difference between barefoot and shod conditions for peak torque and time to peak torque as well as percent strength ratio was correlated with injury ranking using a Spearman rho correlation （p） with an a level of 0.05. Results： The ranked differences in barefoot and shod for peak eversion and inversion torque at 120°/s were correlated with their injury ranking. Ranking of the athletes based on the severity of injuries that were sustained during the season was found to have a strong, positive relationship with the difference in peak eversion torque between barefoot and shod （p = 0.78; p = 0.02）. Conclusion： It is possible that a large discrepancy between strength in barefoot and shod conditions can predispose an athlete to injury. Nar- rowing the difference in peak eversion torque between barefoot and shod could decrease propensity to injury. Future work should investigate the effect of restoration of muscular strength during barefoot and shod exercise on injury rates.展开更多
文摘Purpose: The aim of the present study was to investigate whether street basketball organized as 3 v 3 on either a half court(HC) with 1 basket or a full court(FC) with 2 baskets could improve fitness and health profiles of untrained men after 3 months of supervised training.Methods: Thirty-five untrained men(aged 20—42 years) completed the pre-and post-intervention testing(FC: n = 13, HC: n = 12, CO(control):n = 10). The training attendance was 2.0 ± 0.4 and 1.9 ± 0.3 times per week in FC and HC, respectively. Mean heart rate(HR) was 83.8 ± 6.0 percent of maximal heart rate(%HR_(max)) and 84.5 ± 2.9 %HR_(max) in FC and HC, respectively.Results: The 3 months of street basketball training on an FC with 2 baskets increased maximal oxygen uptake(2.4 mL/min/kg(95% confidence interval(CI): 1.0—3.9)), time to exhaustion(47 s(95%CI: 26—67)), lean body mass(0.8 kg(95%CI: 0.1—1.5)), and bone mineral density(0.021 g/cm^2(95%CI: 0.011—0.031)), whereas mean arterial pressure(—5.6 mm Hg(95%CI: —7.5 to 3.7)), body fat percentage(—1.6%,(95%CI: —2.5 to —0.7)), heart rate(—18 bpm(95%CI: —24 to —12)), and blood lactate(median: —1.4 mmol/L(interquartile range: —1.5 to —0.6)) during submaximal running were lowered. The changes were less pronounced after the training period when playing on an HC with 1 basket, but increases in maximal oxygen uptake(1.6 mL/min/kg(95%CI: —0.1 to 3.3)), time to exhaustion(28 s(95%CI: 9—47)), lean body mass(1.3 kg(95%CI: 0.3—2.4)), and lower body fat percentage(—0.9%(95%CI: —1.9 to —0.1)) were observed in this group.Conclusion: Three months of 3 v 3 street basketball training improved fitness and led to broad-spectrum improvements in variables related to overall health profile, with the most marked effects observed when playing on an FC with 2 baskets.
基金support of the players and coaches in the Rockhampton representative U18 team
文摘Purpose: The aims of this study were to:(1) provide a comprehensive physiological profile of simulated basketball activity and(2) identify temporal changes in player responses in controlled settings.Methods: State-level male basketball players(n = 10) completed 4 × 10 min simulated quarters of basketball activity using a reliable and valid courtbased test. A range of physiological(ratings of perceived exertion, blood lactate concentration([BLa~—]), blood glucose concentration([BGlu]), heart rate(HR), and hydration) and physical(performance and fatigue indicators for sprint, circuit, and jump activity) measures were collected across testing.Results: Significantly reduced [BLa~—](6.19 ± 2.30 vs. 4.57 ± 2.33 mmol/L; p = 0.016) and [BGlu](6.91 ± 1.57 vs. 5.25 ± 0.81 mmol/L;p = 0.009) were evident in the second half. A mean HR of 180.1 ± 5.7 beats/min(90.8% ± 4.0% HR max) was observed, with a significant increase in vigorous activity(77%—95% HR max)(11.31 ± 6.91 vs. 13.50 ± 6.75 min; p = 0.024) and moderate decrease in near-maximal activity(>95% HR_(max))(7.24 ± 7.45 vs. 5.01 ± 7.20 min) in the second half. Small increases in performance times accompanied by a significantly lower circuit decrement(11.67% ± 5.55% vs. 7.30% ± 2.16%; p = 0.032) were apparent in the second half.Conclusion: These data indicate basketball activity imposes higher physiological demands than previously thought and temporal changes in responses might be due to adapted pacing strategies as well as fatigue-mediated mechanisms.
基金Project(50808025) supported by the National Natural Science Foundation of ChinaProject(20090162110057) supported by the Doctoral Fund of Ministry of Education, China
文摘A new vision-based approach was presented for predicting the behavior of the ball carrier—shooting, passing and dribbling in basketball matches. It was proposed to recognize the ball carrier’s head pose by classifying its yaw angle to determine his vision range and the court situation of the sportsman within his vision range can be further learned. In basketball match videos characterized by cluttered background, fast motion of the sportsmen and low resolution of their head images, and the covariance descriptor, were adopted to fuse multiple visual features of the head region, which can be seen as a point on the Riemannian manifold and then mapped to the tangent space. Then, the classification of head yaw angle was directly completed in this space through the trained multiclass LogitBoost. In order to describe the court situation of all sportsmen within the ball carrier’s vision range, artificial potential field (APF)-based information was introduced. Finally, the behavior of the ball carrier—shooting, passing and dribbling, was predicted using radial basis function (RBF) neural network as the classifier. Experimental results show that the average prediction accuracy of the proposed method can reach 80% on the video recorded in basketball matches, which validates its effectiveness.
文摘Background： The majority of injuries reported in female basketball players are ankle sprains and mechanisms leading to injury have been debated. Investigations into muscular imbalances in barefoot versus shod conditions and their relationship with injury severity have not been performed. The purpose of this study was to investigate the effects of wearing athletic shoes on muscular strength and its relationship to lower extremity injuries, specifically female basketball players due to the high incidence of ankle injuries in this population. Methods： During pre-season, 11 female collegiate basketball players underwent inversion and eversion muscle strength testing using an iso- kinetic dynamometer in both a barefoot and shod conditions. The difference between conditions was calculated for inversion and eversion peak torque, time to peak torque as well as eversion-to-inversion peak torque percent strength ratio for both conditions. Lower extremity injuries were documented and ranked in severity. The ranked difference between barefoot and shod conditions for peak torque and time to peak torque as well as percent strength ratio was correlated with injury ranking using a Spearman rho correlation （p） with an a level of 0.05. Results： The ranked differences in barefoot and shod for peak eversion and inversion torque at 120°/s were correlated with their injury ranking. Ranking of the athletes based on the severity of injuries that were sustained during the season was found to have a strong, positive relationship with the difference in peak eversion torque between barefoot and shod （p = 0.78; p = 0.02）. Conclusion： It is possible that a large discrepancy between strength in barefoot and shod conditions can predispose an athlete to injury. Nar- rowing the difference in peak eversion torque between barefoot and shod could decrease propensity to injury. Future work should investigate the effect of restoration of muscular strength during barefoot and shod exercise on injury rates.
