Background: This study aimed to investigate the accuracy and reliability of a free mobile heart rate variability (HRV) application in measuring HRV. Methods: Twelve females and 12 males underwent five-minute simultaneous HRV recording from electrocardiogram (ECG) and chest strap connected to a free mobile HRV application (HRVapp) in a supine position. HRV data from ECG and HRVapp were used to examine accuracy and reliability via relative error and intraclass correlation coefficient respectively. Results: The natural log of the square root of the mean of the sum of the squares of differences between adjacent normal to normal intervals (lnRMSSD) exhibited accuracy and high reliability in HRVapp. Conclusion: lnRMSSD in HRVapp can serve as an alternative, low-cost technology for measurement of autonomic activity.

Abstract The aim of the present study was to compare the aerobic and anaerobic power and capacity of elite male basketball players who played multiple positions. Fifty-five healthy players were divided into the following three different subsamples according to their positional role: guards (n = 22), forwards (n = 19) and centers (n = 14). The following three tests were applied to estimate their aerobic and anaerobic power and capacities: the countermovement jump (CMJ), a multistage shuttle run test and the Running-based Anaerobic Sprint Test (RAST). The obtained data were used to calculate the players’ aerobic and anaerobic power and capacities. To determine the possible differences between the subjects considering their different positions on the court, one-way analysis of variance (ANOVA) with the Bonferroni post-hoc test for multiple comparisons was used. The results showed that there was a significant difference between the different groups of players in eleven out of sixteen measured variables. Guards and forwards exhibited greater aerobic and relative values of anaerobic power, allowing shorter recovery times and the ability to repeat high intensity, basketball-specific activities. Centers presented greater values of absolute anaerobic power and capacities, permitting greater force production during discrete tasks. Coaches can use these data to create more individualized strength and conditioning programs for different positional roles.

Background: The application of whole body vibration (WBV) as a warm-up scheme has been receiving an increasing interest among practitioners. Objectives: The aim of this study was to determine the effect of loaded and unloaded WBV on countermovement jump, speed and agility. Patients and Methods: Twenty-one healthy male college football players (age: 20.14 ± 1.65 years; body height: 179.9 ± 8.34 cm; body mass: 74.4 ± 13.0 kg; % body fat: 9.45 ± 4.8) underwent randomized controlled trials that involved standing in a half squat position (ST), ST with 30% of bodyweight (ST + 30%), whole body vibration at f = 50 Hz, A = 4 mm (WBV), and WBV with 30% bodyweight (WBV + 30% BW) after a standardized warm-up. Post measures of countermovement jump, 15-m sprint, and modified t-test were utilized for analyses. Results: One way repeated measures ANOVA revealed a significant difference in the countermovement jump performance, F (3, 60 = 9.06, η2 = 2.21, P = 0.000. Post-hoc showed that WBV + 30% BW posted significant difference compared to (P = 0.008), ST + 30% BW (P = 0.000) and WBV (P = 0.000). There was also a significant difference in the sprint times among interventions, F (3, 60) = 23.0, η2 = 0.865, P = 0.000. Post hoc showed that WBV + 30% BW displayed significantly lower time values than ST (P = 0.000), ST + 30% BW (P = 0.000) and WBV (P = 0.000). Lastly, there was a significant difference in the agility performance across experimental conditions at F(2.01, 40.1) = 21.0, η2 = 0.954, P = 0.000. Post hoc demonstrated that WBV have lower times than ST (P = 0.013). Also, WBV + 30% BW posted lower times compared to ST (P = 0.000), ST + 30% (P = 0.000) and WBV (P = 0.003). Conclusions: Additional external load of 30% bodyweight under WBV posted superior gains in countermovement jump, speed and agility compared to unloaded WBV, loaded non-WBV and unloaded non-WBV interventions.

The aim of the present study was to compare the effects of different warm-up interventions on jump, sprint and agility performance in collegiate soccer players. Twenty-one healthy male college soccer players (age: 20.14 ± 1.65 years; body height: 179.9 ± 8.34 cm; body mass: 74.4 ± 13.0 kg; % body fat: 9.45 ± 4.8) participated in the study. Subjects underwent four different randomized warm-up protocols separated by at least 48 hours. The warm-up schemes were: 1. no conditioning contraction protocol (NCC); 2. dynamic stretching (DS); 3. prolonged intermittent low-intensity isometric exercise (ST); and, 4. ST with an additional external load equal to 30% of body weight (ST + 30% BW). All interventions were preceded by a general warm-up. Results from one-way repeated measures ANOVA demonstrated a significant difference in countermovement jump (CMJ) at F(3,60) = 10.2, ηρ2 = 0.337, p < 0.01. Post hoc analysis revealed a significant difference in CMJ performance in DS when compared to NCC and ST + 30% BW. No significant difference in CMJ was observed between DS and ST. CMJ scores in NCC, ST, and ST + 30% BW were non-significant. There was a significant difference in speed; F(3, 60) = 6.61, ηρ2 = 0.248, p < 0.01. Post hoc analysis revealed significantly better time in DS than NCC and ST. However, no difference in speed was observed between DS and ST + 30% BW. Similarly, speed was similar in NCC, ST and ST + 30% BW. A significant difference in agility performance was also observed; F(3, 60) = 24.1, ηρ2= 0.546, p < 0.01. Post hoc analysis revealed significantly greater performance gains in DS than NCC. No significant difference in agility was observed in DS, ST and ST + 30% BW. In conclusion, a prolonged intermittent low-intensity isometric protocol using bodyweight only showed similar benefits with dynamic stretching in countermovement jump performance. When the same isometric condition with additional load equal to 30% of bodyweight was applied, effects in speed and agility were similar to dynamic stretching.

The aim of this study was to examine the relationships among physical fitness of professional Bosnianbasketball players (n = 38) and shooting accuracy during one basketball season. A related, secon ...

The aim of this research was the estimation of anthropometric characteristics of elite male basketball players from four Bosnian first league teams, as well as the identification of possible differ ...