There is little knowledge about within- and between-referee variation (WBRV) in cardiovascular responses (CVR) and locomotor game demands (LMD). Thus, the primary aim of this study was to assess the WBRV of CVR and LMD in male basketball referees during elite international games in preparation [e.g., warm-up (WU) and re-warm-up (R-WU)] and active game phases. The secondary aim was to explore quarter-by-quarter differences in CVR and LMD. Thirty-five international male referees took part in this study (age, 40.4 ± 5.4 years; body height, 184.9 ± 5.7 cm; body weight, 85.1 ± 7.5 kg; BMI, 24.0 ± 1.7 kg × m−2; fat%, 18.8 ± 4.7% and VO2max, 50.4 ± 2.2 L × kg−1 × min−1. In total, 76 games (e.g., 228 officiating cases) were analyzed during the FIBA elite men’s competition. They officiated 4.5 games on average (range 3–9 games). Each referee used the Polar Team Pro system to measure CVR [e.g., heart rate (HR), time spent in different HR intensity categories] and LMD (e.g., distance covered, maximal and average velocity, and number of accelerations). Results showed that the referees had bigger WBRV during the active and preparation (e.g., W-U than R-WU) phase when variables of higher CVR and LMD intensity were observed (e.g., time spent at higher HR zones, distance covered in higher speed zones). The WBRV, CVR, and LMD were higher during WU than R-WU. Moreover, the referees had a lower CVR and LMD in the second half. In conclusion, the referees should establish and follow consistently a game-to-game preparation routine and attempt to spread their on-court preparation time equally within the crew. A half-time preparation routine should be improved to re-establish a sufficient activation level similar to that achieved in pre-game preparation.

This study aimed to investigate the reliability, validity, and sensitivity of spatiotemporal parameters, during sprint skating, of bandy players. Thirty-two well-trained male bandy players (age: 17.8 ± 1.2 years; height: 1.80 ± 0.06 m; body mass: 75.7 ± 1.2 kg) participated in this study. They performed two 80 m linear skating sprints. To calculate the velocities and obtain glide-by-glide spatiotemporal variables, nine timing gates and two skate-mounted inertial measurement units (IMUs) were synchronized and used. The spatiotemporal variables at each step included the glide time, glide length, double support time, double support length, step length, and step frequency. All the spatiotemporal variables were analyzed separately: averaged over 80 m, during the acceleration, and the maximal steady-state phases. The relative and absolute reliability of the spatiotemporal parameters were good (ICC > 0.70; CV < 10%), except for the step frequency during the steady-state phase. The spatiotemporal parameters showed “good” to “satisfactory” sensitivity during the acceleration phase and whole sprint, and “marginal” sensitivity during the steady-state phase. Content validity was confirmed by a low percentage of the shared variance (17.9–34.3%) between the spatiotemporal parameters obtained during the acceleration and steady-state phases. A “stepwise” regression significantly predicted the steady-state skating velocity from the spatiotemporal metrics obtained during the acceleration [F(5,26) = 8.34, p < 0.001, adj. R2 = 0.62] and steady-state phases [F(5,26) = 13.6, p < 0.01, R2 = 0.67]. Only the step frequency obtained in the acceleration phase significantly predicted the maximal skating velocity (p < 0.01), while the glide length and step frequency derived during the steady-state phase significantly added to the prediction (p < 0.01). In conclusion, the spatiotemporal parameters, obtained by two skate-mounted IMUs, were shown to be reliable and sensitive measures of sprint skating, and they could be used to provide independent information for the different skating phases. The maximal skating velocity could be predicted from the spatiotemporal parameters, with longer gliding and more frequent steps as the most significant determinants.

We investigated the acute effects of different whole-body vibration (WBV) interventions on the jump height of highly trained karate practitioners. Fifteen male karate club athletes (age: 20.0 ± 3.8 years; stature: 177.3 ± 4.7 cm; body mass: 76.9 ± 11.2 kg; % body fat: 9.2 ± 4.3) performed six randomized interventions: [a] static half-squat (SHS); [b] SHS with external loads at 30% of the body weight (SHS + 30%BW); [c] WBV at frequency (f) 25 Hz, and 2 mm amplitude (A) (WBV 25/2); [d] WBV 25/2 with external loads of 30% of the body weight (WBV 25/2 + 30% BW); [e] WBV at f = 50 Hz, and A = 4 mm (WBV 50/4), and [f] WBV 50/4 with external loads of 30% of the body weight (WBV 50/4 + 30% BW). Each intervention was performed for 5 sets at 60 s/set, with a rest interval of 30 s between sets. Countermovement jump (CMJ) data were collected at 2, 4, 6, 8 and 10 min after each preconditioning intervention. Two-way repeated-measures ANOVA revealed a non-significant main effect of intervention [F(5, 10) = 1.44, η2 = 0.42, p = 0.29)] and a significant main effect of the rest interval [F(4, 11) = 3.51, η2 = 0.56, p = 0.04)] on CMJ height. A rest interval of 4 min resulted in significantly higher CMJ values than a rest interval of 2 min (p = 0.031). In conclusion, utilizing a 4-min rest interval irrespective of the intervention schemes may have potential for enhancing jumping performance among highly trained karate athletes.

Introduction Although previous research found that small-sided game (SSG) training was more enjoyable than high-intensity interval training (HIT) in various sports, no data were provided during longer training period in basketball. Furthermore, the comparison of internal loads between the two training approaches needs to be further examined. Thus, this study aimed to examine the acute physiological, perceived exertion and enjoyment responses during 4-week progressive basketball SSG or HIT programs. Methods Nineteen female collegiate basketball players were randomly assigned to two groups that performed either HIT (n = 10) or SSG (n = 9) 3 times per week for 4 continuous weeks. Average and percentage of maximal heart rate (HRmean and %HRmax), rating of perceived exertion (RPE), and physical activity enjoyment (PACES) were determined during each training session. Results There was a main group effect in PACES (p < 0.001; η p 2 = 0.44, moderate), and SSG had higher PACES than HIT in each week (p < 0.05). There were no significant interactions or main group effects in HRmean, %HRmax or RPE, but a main time effect was found in HRmean (p = 0.004; η p 2 = 0.16, minimum), %HRmax (p < 0.001; η p 2 = 0.25, minimum), and RPE (p < 0.001; η p 2 = 0.31, moderate), respectively. In the SSG group, although no significant differences were found in HR responses, %HRmax was below 90% in week 1 and week 2. Accompanied with changes in %HRmax, RPE in week 1 and week 2 was lower than that in week 3 and week 4 (p < 0.05). Conclusion Our findings suggest that SSG and HIT elicit similar acute HR response and RPE level, but SSG is perceived as more enjoyable and therefore it is more likely to increase exercise motivation and adherence comparing to HIT. Moreover, it seems that half-court, 2 vs. 2 SS Gtraining format with modified rules and lasting ≥ 7.5 min should be prescribed as an enjoyable training alternative to provide optimal cardiovascular stimuli (> 90% of HRmax) for female basketball players.

This study aimed to compare sprint skating profile characteristics of the different playing positions of junior and senior bandy players. In total, 111 male national-level bandy players (age: 20.7 ± 5.0 years, height: 1.80 ± 0.05 m, body mass: 76.4 ± 0.4 kg, training experience: 13.8 ± 5.0 yrs) were tested on their sprint skating profile over 80 m. The main findings were that no differences between positions were found in sprint skating performance (speed and acceleration), but that elite players were in general heavier (p < 0.05) than junior players (80.0 ± 7.1 vs. 73.1 ± 8.1 kg), they could accelerate faster (2.96 ± 0.22 vs. 2.81 ± 0.28 m/s2), and they reached a higher velocity (10.83 ± 0.37 vs. 10.24 ± 0.42 m/s) earlier over 80 m than the junior players. This implies that junior level players should spend more time in power and sprint training to meet the specific demands of playing at a higher, elite level.

There is no research examining female bandy players, which creates a gap of knowledge of female skating performance and its determinants with male skating performance, not only in bandy but also in exercise science in general. Therefore, the aim of this explorative study was to investigate position and playing-level differences in the sprint skating performance and anthropometrics of 74 elite female bandy players (age: 18.9 ± 4.1 years; height: 1.67 ± 0.06 m; body mass: 63.2 ± 7.4 kg). Participants were categorised according to playing level (26 elite and 48 junior elite players) and position (22 defenders, 35 midfielders, and 17 forwards). They were tested on their anthropometric characteristics and sprint linear skating profile over 80 m with the split times measured at 10, 20, 40, 50, 60, 70, and 80 m to calculate the average velocities between these different 10 m intervals. Results revealed that elite players had more training experience, were heavier, could accelerate faster, and reached a higher maximal velocity than the junior elite players (9.52 ± 0.37 vs 8.84 ± 0.40 m/s, respectively). In general, defenders were heavier than forwards, and the elite forwards accelerated faster in the first 10 m than the midfielders (p = 0.041). In summary, playing level and position, body mass, and training experience modulated skating sprint performance. The findings suggest that female junior-level players should spend more time developing skating sprint and acceleration abilities to meet the specific demands of playing at the elite level. Moreover, the coaches and professionals who work with female bandy players should be aware that the development of acceleration ability is more important for forwards.

Introduction: The aim of this study was to investigate the association between physical fitness, physical activity, and sense of coherence (SOC) in Swedish adolescents (n = 2028 males, n = 1287 females) aged 14 to 18 using a cross-sectional design. Methods: Using the Swedish Physical power Mental harmony and Social capacity (FMS) student profile, participants performed physical tests measuring their cardiovascular ability (CV) and muscular strength. Questionnaires were used to measure physical activity levels (PA), the participation in organized physical training, sedentary behavior (SB), screen time, and SOC value. Multiple linear regression analyses were used to analyze the association between SOC and independent variables. Results: The regression analyses explained a small, shared variance between SOC and the independent variables in boys (4.3%) and girls (3.3%). SB showed a positive association with SOC both in girls (β = 0.114, p = 0.002) and boys (β = 0.109, p = 0.013). Abdominal strength was positively associated, while VO2max was inversely associated, with SOC (β = 0.113, p = 0.022; β = −0.109, p = 0.026, respectively) in boys. Girls had poorer fitness than boys did across all age groups except at age 18. PA levels decreased from age 14 to 18 in girls and boys, but without differences between sexes. Abdominal strength decreased from age 14 to 18 in girls and boys. In general, girls had lower SOC than boys across all age groups. Conclusions: Poor sedentary behavior was significantly associated with weaker SOC for both genders, indicating overall physical activity as the most important factor for stronger SOC. However, emotional support in vulnerable environments may have a bigger impact than physical activity or sedentary behavior on the SOC value for adolescents.

INTRODUCTION MATERIALS AND METHODS

Although high and simulated altitude training has become an increasingly popular training method, no study has investigated the influence of acute hypoxic exposure on balance in team-sport athletes. Therefore, the purpose of this study was to investigate whether acute exposure to normobaric hypoxia is detrimental to balance performance in highly-trained basketball players. Nine elite and nine sub-elite male basketball players participated in a randomized, single-blinded, cross-over study. Subjects performed repeated trials of a single-leg balance test (SLBT) in an altitude chamber in normoxia (NOR; approximately sea level) with FiO2 20.9% and PiO2 ranging from 146.7 to 150.4 mmHg and in normobaric hypoxia (HYP; ~3,800 m above sea level) with FiO2 13.0% and PiO2 ranging from 90.9 to 94.6 mmHg. The SLBT was performed three times: 15 min after entering the environmental chamber in NOR or HYP, then two times more interspersed by 3-min rest. Peripheral oxygen saturation (SpO2) and heart rate (HR) were recorded at four time points: after the initial 15-min rest inside the chamber and immediately after each SLBT. Across the cohort, the balance performance was 7.1% better during NOR than HYP (P < 0.01, ηp2 = 0.58). However, the performance of the elite group was not impaired by HYP, whereas the sub-elite group performed worse in the HYP condition on both legs (DL: P = 0.02, d = 1.23; NDL: P = 0.01, d = 1.43). SpO2 was lower in HYP than NOR (P < 0.001, ηp2 = 0.99) with a significant decline over time during HYP. HR was higher in HYP than NOR (P = 0.04, ηp2 = 0.25) with a significant increase over time. Acute exposure to normobaric hypoxia detrimentally affected the balance performance in sub-elite but not elite basketball players.