Shot Distribution and Accuracy in Senior and Youth International Basketball Games: Changes over the Decade of the 2010s.

This study aimed to investigate the changes in shot distribution and accuracy in senior and under-17 international basketball tournaments in the 2010s. A retrospective cross-sectional design was employed, and a total of 1055 games from 20 world-level tournaments held between 2010 and 2019 were analyzed. The tournaments held in 2010 were played under the old three-point line (6.25 m), and the rest of the tournaments were played under the new three-point line (6.75 m). The numbers of two- and three-point shot attempts in each game were normalized to 100 possessions. Differences in mean values of two- and three-point shot attempts were analyzed by a two-way (category × year) between-subjects analysis of variance (ANOVA). Differences in the success rates of two- and three-point shots were analyzed by Fisher's exact test. There was no significant category × year interaction for two-point shot attempts. However, there were significant main effects of category and year for two-point shot attempts. The number of two-point shot attempts increased significantly in 2012 and, in 2016, returned to a level not significantly different from that in 2010, independent of categories. There was a significant category × year interaction for three-point shot attempts. The number of three-point shot attempts decreased significantly in 2012 and, by 2016, returned to a level not significantly different from that in 2010 in senior men and under-17 women. There was no significant change in the number of three-point shot attempts in under-17 men. The effect of the extension of the three-point line on shot accuracy was limited. Differences in shot accuracy were prominent between age categories: the accuracy was lower in under-17 games than in senior games for both sexes. Although under-17 men attempted fewer three-point shots than senior men, under-17 women attempted a similar number of or more three-point shots than senior women. These findings can contribute to a better understanding of age and sex differences in recent trends in international basketball.

Basketball Game-Related Statistics that Discriminate among Continental Championships for Under-18 Women.

The purposes of this study were (a) to evaluate differences in basketball game-related statistics among continental championships for under-18 (U18) women, and (b) to identify game-related statistics that discriminate among the continents. The analysis was performed on all matches (n = 136) in the four continental championships (Africa, America, Asia, Europe) of 2016. Differences in game-related statistics among the continents were analyzed by an analysis of variance (ANOVA) with effect size statistics. Game-related statistics that discriminate among the continents were assessed by discriminant analysis. The ANOVA yielded significant F-values for 13 of 16 variables and large effect size differences for 10 of 16 variables. The discriminant analysis yielded three significant functions. The Asian championship was discriminated from the other continental championships by ball possessions, defensive rebounds, assists, and fouls. The African championship was discriminated from the European championship by ball possessions, successful 3-point field goals, unsuccessful free throws, and turnovers, and from the American championship by ball possessions, unsuccessful 2-point field goals, successful 3-point field goals, successful free throws, and assists. The results of this study suggest that U18 women's basketball games are played differently in each continent.

Regional Differences in Women's Basketball: A Comparison among Continental Championships.

The aims of this study were (i) to compare basketball game-related statistics in women by region (Africa, America, Asia, Europe), and (ii) to identify characteristics that discriminate performances for each region. A total of 134 games from each continental championship held in 2017 were analyzed. A one-way ANOVA followed by a Bonferroni-adjusted pairwise comparison was performed to evaluate differences in each variable between the continents. A discriminant analysis was performed to identify game-related statistics that discriminate among the continents. The Asian and European championships overall showed similar performance profiles: Low numbers of possessions and turnovers, and high numbers of successful field goals and assists. However, the European championship was more closely contested than the Asian championship. The African championship was characterized by high numbers of possessions, free throws, and turnovers. The homogeneity of the American championship was low, and some of the cases have similarities with the African championship, whereas other cases have similarities with the European championship. On average, the American championship was characterized by low numbers of successful field goals and assists, and high numbers of steals and turnovers. It is suggested that women's basketball games are played in a different manner in each region of the world.

Postexercise blood flow restriction does not enhance muscle hypertrophy induced by multiple-set high-load resistance exercise.

To test the applicability of postexercise blood flow restriction (PEBFR) in practical training programmes, we investigated whether PEBFR enhances muscle hypertrophy induced by multiple-set high-load resistance exercise (RE). Seven men completed an eight-week RE programme for knee extensor muscles. Employing a within-subject design, one leg was subjected to RE + PEBFR, whereas contralateral leg to RE only. On each exercise session, participants performed three sets of unilateral knee extension exercise at approximately 70% of their one-repetition maximum for RE leg first, and then performed three sets for RE + PEBFR leg. Immediately after completion of the third set, the proximal portion of the RE + PEBFR leg was compressed with an air-pressure cuff for 5 min at a pressure ranging from 100 to 150 mmHg. If participants could perform 10 repetitions for three sets in two consecutive exercise sessions, the work load was increased by 5% at the next exercise session. Muscle thickness and strength of knee extensor muscles were measured before and after the eight-week training period and after the subsequent eight-week detraining period. There was a main effect of time but no condition × time interaction or main effect of condition for muscle thickness and strength. Both muscle thickness and strength increased after the training period independent of the condition. This result suggests that PEBFR would not be an effective training method at least in an early phase of adaptation to high-load resistance exercise.

Age and sex differences in game-related statistics which discriminate winners from losers in elite basketball games

AIMS: To advance knowledge of long-term development of basketball players, this study investigated age and sex differences in game-related statistics which discriminate winners from losers in World Basketball Championships held after the 2010 rule change. METHODS: A total of 935 games from six categories (under-17, under-19 and open age for both men and women) were analyzed. All games were classified into three types (balanced, unbalanced and very unbalanced) according to point differential by a k-means cluster analysis. A discriminant analysis was performed to identify game-related statistics which discriminate winners from losers in each game type. An absolute value of a structural coefficient (SC) equal to or above 0.30 was considered relevant for the discrimination. RESULTS: In balanced games, assists discriminated winners from losers in open games (men, -SC- = 0.32; women, -SC- = 0.34), whereas successful free throws did so in under-17 games (men, -SC- = 0.30; women, -SC- = 0.31). Successful 2-point field goals discriminated winners from losers only in women's games (under-19, -SC- = 0.38; open, -SC- = 0.36). CONCLUSION: There were three novel findings in balanced games: 1) successful free throws but not assists discriminated winners from losers in under-17 games; 2) successful 2-point field goals discriminated winners from losers in women's games but not in men's games; and 3) discriminating power of successful 3-point field goals was extremely small in women's games. These results may be related to the new rules for the shot clock and the 3-point distance.(AU)

Are regional differences in basketball already established in under-18 games?

To identify regional differences in basketball games for under-age categories, this study analyzed game-related statistics of four continental championships for under-18 (U18) men. Methods: A total of 149 games from each continental championship for U18 men held in 2016 were analyzed. A one-way analysis of variance followed by a Bonferroni post hoc test was performed to assess differences in game-related statistics between the continents (Europe, Africa, America, Asia). A discriminant analysis was performed to identify game-related statistics which discriminate among the continents. Results: The U18 African championship, which was characterized by a high number of free throws, was clearly discriminated from any other U18 continental championship. Among the other U18 continental championships excluding the African championship, the biggest difference was observed between the European and the Asian championships. The U18 European championship was characterized by a low number of possessions and a high number of assists, whereas the U18 Asian championship was characterized by a high number of possessions and a low number of assists. Both possessions and assists showed high numbers in the U18 American championship. Conclusion: This study identified regional differences in basketball games among four continental championships for U18 men held in 2016. It is suggested that basketball games for under-age categories are played in a different manner in each region of the world. The information derived from this study will help players and coaches of under-age national teams prepare for international competitions.(AU)

Effect of very low-intensity resistance training with slow movement on muscle size and strength in healthy older adults.

We previously reported that low-intensity [50% of one repetition maximum (1RM)] resistance training with slow movement and tonic force generation (LST) causes muscle hypertrophy and strength gain in older participants. The aim of this study was to determine whether resistance training with slow movement and much more reduced intensity (30%1RM) increases muscle size and strength in older adults. Eighteen participants (60-77 years) were randomly assigned to two groups. One group performed very low-intensity (30% 1RM) knee extension exercise with continuous muscle contraction (LST: 3-s eccentric, 3-s concentric, and 1-s isometric actions with no rest between each repetition) twice a week for 12 weeks. The other group underwent intermitted muscle contraction (CON: 1-s concentric and 1-s eccentric actions with 1-s rest between each repetition) for the same time period. The 1RM, isometric and isokinetic strengths, and cross-sectional image of the mid-thigh obtained by magnetic resonance imaging were examined before and after the intervention. LST significantly increased the cross-sectional area of the quadriceps muscle (5.0%, P<0.001) and isometric and isokinetic knee extension strengths (P<0.05). CON failed to increase muscle size (1.1%, P = 0.12), but significantly improved its strength (P<0.05). These results indicate that even if the intensity is as low as 30% 1RM, LST can increase muscle size and strength in healthy older adults. The large total contraction time may be related to muscle hypertrophy and strength gain. LST would be useful for preventing sarcopenia in older individuals.

Haemostatic and inflammatory responses to blood flow-restricted exercise in patients with ischaemic heart disease: a pilot study.

Low-intensity resistance exercise can effectively induce muscle hypertrophy and increases in strength when combined with moderate blood flow restriction (BFR). As this type of exercise does not require lifting heavy weights, it might be a feasible method of cardiac rehabilitation, in which resistance exercise has been recommended to be included. Although previous studies with healthy subjects showed relative safety of BFR exercise, we cannot exclude the possibility of unfavourable effects in patients with cardiovascular disease. We therefore aimed to investigate haemostatic and inflammatory responses to BFR exercise in patients with ischaemic heart disease (IHD). Nine stable patients with IHD who were not taking anticoagulant drugs performed four sets of knee extension exercise at an intensity of 20% one-repetition maximum (1RM) either with or without BFR. Blood samples were taken before, immediately after and 1 h after the exercise session and analysed for noradrenaline, D-dimer, fibrinogen/fibrin degradation products (FDP) and high-sensitive C-reactive protein (hsCRP). Plasma noradrenaline concentration increased after the exercise, and the increase was significantly larger after the exercise with BFR than without BFR. On the other hand, increases in concentrations of plasma D-dimer and serum hsCRP were independent of the condition. However, increases in D-dimer and hsCRP were no longer observed after plasma volume correction, suggesting that hemoconcentration was responsible for these increases. Plasma FDP concentration did not change after the exercise. These results suggest that applying BFR during low-intensity resistance exercise does not affect exercise-induced haemostatic and inflammatory responses in stable IHD patients.

Blood flow-restricted training does not improve jump performance in untrained young men.

The purpose of this study was to investigate the effect of blood flow-restricted training (BFRT) on jump performance in relation to changes in muscle strength. Seventeen untrained young men were assigned into either BFRT or normal training (NORT) groups and performed low-intensity [30-40% of one-repetition maximum (1RM)] resistance exercise (horizontal squat, 3-4 sets × 15-30 repetitions) twice a week for 10 weeks. The BFRT performed the exercise with their proximal thighs compressed by air-pressure cuffs for the purpose of blood flow restriction. Squat 1RM, muscle cross-sectional area (CSA) of quadriceps femoris, and countermovement jump (CMJ) height were measured before and after the 10-wk training period. Squat 1RM increased greater in BFRT than in NORT (19.3% vs. 9.7%, P < 0.01). Although the CSA increase was independent of groups, it tended to be larger in BFRT than in NORT (8.3% vs. 2.9%, P = 0.094). On the other hand, CMJ height did not change after the training (P = 0.51). In conclusion, the present study showed that BFRT induced muscle hypertrophy and strength increase, whereas it did not increase CMJ height in previously untrained young men. It is suggested that BFRT is ineffective in improving jump performance.

Increase in serum growth hormone induced by electrical stimulation of muscle combined with blood flow restriction.

The purpose of this study was to investigate the role of muscle metaboreflex on exercise-induced growth hormone (GH) secretion. In order to accumulate metabolites within exercised muscle with minimized central motor activity, electromyostimulation (EMS) was performed combined with blood flow restriction (BFR). Seven men performed one-legged isometric knee extension evoked by EMS (frequency, 20 Hz; pulse duration, 400 µs; on-off ratio, 3-1 s). Just before the exercise, proximal portion of either a stimulated thigh (ST) or a non-stimulated thigh (NT) was compressed at 150 mmHg with an air-pressure cuff for the purpose of BFR. The compression was kept throughout the exercise session, and was released 2 min after the end of the exercise. Two exercise sessions (ST(BFR), BFR for ST; NT(BFR), BFR for NT) were separated by 1 week. ST(BFR) was aimed to accumulate metabolites within exercised muscle, whereas NT(BFR) was aimed to match mechanical stress with ST(BFR) without accumulating metabolites. Blood samples for hormonal measurements were taken from the antecubital vein before and after the exercise. Blood lactate increased immediately after the exercise in the NT(BFR), whereas it increased after the cuff deflation in the ST(BFR), suggesting that locally produced metabolites were retained and accumulated within the exercised muscle in the ST(BFR). Although serum cortisol and plasma noradrenaline increased in a similar manner in two conditions, serum immunoreactive GH (irGH) increased only in the ST(BFR). These results suggest that muscle metaboreflex plays an important role in the exercise-induced GH secretion, at least in terms of irGH secretion.

Pentraxin3 and high-sensitive C-reactive protein are independent inflammatory markers released during high-intensity exercise.

High-intensity exercise shares similarities with acute phase responses of inflammatory diseases. We investigated the influences of acute exercise on inflammatory markers, plasma pentraxin3 (PTX3) and serum high-sensitive C-reactive protein (CRP) (hsCRP). Nine healthy male subjects (41 ± 3 years old) participated. Each subject performed three types of exercise; ergometer exercise at 70% workload of anaerobic threshold (AT) for 30 min (70% AT exercise), peak ergometer exercise (peak EX, 20 watt increase/min until fatigue) and resistance exercises of 70% 1 RM (70% RE) until exhaustion. We measured plasma PTX3, serum hsCRP, lactate, noradrenaline (NOR), white blood cells (WBC), interleukin-6 (IL-6) and myeloperoxidase (MPO), a marker of neutrophil degranulation. The effects of exercise on intracellular PTX3 and MPO in neutrophils were also investigated, by using flow cytometry analysis. Circulating PTX3 and hsCRP significantly increased immediately after 70% RE and peak EX, while they did not increase after 70% AT exercise. The exercise-induced fold increase in PTX3 and hsCRP relative to the resting level was positively correlated with the changes in WBC, NOR, lactate and MPO. The exercise-induced fold increase in IL-6 was positively correlated with that in NOR, but not with that in PTX3 and hsCRP. Neutrophils isolated immediately after 70% RE, but not 70% AT exercise, exhibited lower mean fluorescence for PTX3 and MPO than those from pre-exercise blood. These results provide the evidence that high-intensity exercises significantly increase circulatory PTX3 as well as hsCRP. The release from peripheral neutrophils is suggested to be involved in the exercise-induced plasma PTX3 increase.

Effects of low-intensity resistance exercise with blood flow restriction on coagulation system in healthy subjects.

Recent studies have demonstrated that even a low-intensity resistance exercise can effectively induce muscle hypertrophy and strength increase when combined with moderate blood flow restriction (BFR) into the exercising muscle. Although serious side effects of low-intensity resistance exercise with BFR have not been reported, a concern of thrombosis has been suggested, because this type of exercise is performed with restricted venous blood flow and pooling of blood in extremities. Thus, the purpose of this study was to investigate the effects of low-intensity resistance exercise with BFR on coagulation system in healthy subjects. Ten healthy men (25.1 +/- 2.8 year) performed four sets of leg press exercises with and without BFR (150-160 mmHg) at an intensity of 30% of one-repetition maximum (1RM). In each exercise session, one set with 30 repetitions was followed by three sets with 15 repetitions. Blood samples were taken before, and 10 min, 1, 4 and 24 h after the exercise. Prothrombin fragment 1 + 2 (PTF) and thrombin-antithrombin III complex (TAT) were measured as markers of thrombin generation, whereas D-dimer and fibrin degradation product (FDP) were measured as markers of intravascular clot formation. Changes in plasma volume (PV) were calculated from haemoglobin and hematocrit values. PV reduction was significantly greater after the exercise with BFR than without (P<0.05). However, neither markers of thrombin generation nor intravascular clot formation increased after the exercises. These results suggest that low-intensity resistance exercise with BFR does not activate coagulation system in healthy subjects.

Cross-transfer effects of resistance training with blood flow restriction.

PURPOSE: This study investigated whether muscle hypertrophy-promoting effects are cross-transferred in resistance training with blood flow restriction, which has been shown to evoke strong endocrine activation. METHODS: Fifteen untrained men were randomly assigned into the occlusive training group (OCC, N = 8) and the normal training group (NOR, N = 7). Both groups performed the same unilateral arm exercise (arm curl) at 50% of one-repetition maximum (1RM) without occlusion (three sets, 10 repetitions). Either the dominant or nondominant arm was randomly chosen to be trained (OCC-T, NOR-T) or to serve as a control (OCC-C, NOR-C). After the arm exercise, OCC performed leg exercise with blood flow restriction (30% of 1RM, three sets, 15-30 repetitions), whereas NOR performed the same leg exercise without occlusion. The training session was performed twice a week for 10 wk. In a separate set of experiments, acute changes in blood hormone concentrations were measured after the same leg exercises with (N = 5) and without (N = 5) occlusion. RESULTS: Cross-sectional area (CSA) and isometric torque of elbow flexor muscles increased significantly in OCC-T, whereas no significant changes were observed in OCC-C, NOR-T, and NOR-C. CSA and isometric torque of thigh muscles increased significantly in OCC, whereas no significant changes were observed in NOR. Noradrenaline concentration showed a significantly larger increase after leg exercise with occlusion than after exercises without occlusion, though growth hormone and testosterone concentrations did not show significant differences between these two types of exercises. CONCLUSION: The results indicate that low-intensity resistance training increases muscular size and strength when combined with resistance exercise with blood flow restriction for other muscle groups. It was suggested that any circulating factor(s) was involved in this remote effect of exercise on muscular size.