Effects of beta-blockers on archery performance, body sway and aiming behaviour.

OBJECTIVES: This study aimed to determine the effect of selective (bisoprolol-5 mg) and non-selective (propranolol-40 mg) beta-blockers on archery performance, body sway and aiming behaviour. METHODS: Fifteen male archers participated in a randomised, double-blind, placebo-controlled, cross-over study and competed four times (control, placebo, selective (bisoprolol) and non-selective (propranolol) beta-blocker trials). Mechanical data related to the changes in the centre of pressure during body sway and aim point fluctuation and when shooting was collected. During the shots, heart rate was recorded continuously. RESULTS: Results indicated that, in beta-blocker trials, although shooting heart rates were lowered by 12.8% and 8.6%, respectively, for bisoprolol and propranolol, no positive effect of beta-blockers was observed on shooting scores. Also, the use of beta-blockers did not affect shooting behaviour and body sway. CONCLUSION: The use of either selective or non-selective single dose beta-blockers had no positive effect on shooting performance in archery during simulated match conditions.

Effect of heart rate on shooting performance in elite archers.

AIM: The aim of the present study was to examine the effect of heart rate on shooting performance in elite archers. METHODS: Regularly trained 13 (7 female, 6 male) international level elite archers performed a (specific) protocol twice with 3 days interval in an indoor area. In order to raise the heart rate (HR) and related physiological stress the archers performed 4 sets of steady pace shuttle runs (males 10 km h-1; females 8 km h-1) for 3 minutes in a 20 m course following with 1 minute stop during which they performed 3 shots to 18 meter distance indoor target, and followed by 1 minute rest, where blood sample was collected from ear lobe for blood lactate (BL) analysis. Heart rate monitors were used for heart rate (HR) recordings with 5 seconds intervals for resting, running, shooting, and recovery periods. The score of the shots were recorded as in the normal archery indoor competition. Average (overall) results were taken into account for statistical analysis. RESULTS: Mean HR and BL during resting shoot in 1st and 2nd tests were 119.0 and 112.2 bpm (range 1st test: 101-142 bpm, 2nd test: 96-135 bpm) and 1.72 and 1.65 mmol.L-1 (range 1st test: 0.9-2.6 mmol.L-1, 2nd test: 0.8-2.3 mmol.L-1) respectively. Mean HR and BL during post exercise shooting in 1st and 2nd tests were 168 and 166 bpm (range 1st test: 152-191 bpm, 2nd test: 147-188 bpm) and 4.21 and 3.44 mmol.L-1 (range 1st test: 1.3-7.0 mmol.L-1, 2nd test: 1.3-5.7 mmol.L-1) respectively. There was not any statistically difference between shooting scores (27.50-27.23 points) after running exercise and resting (p > 0.05). CONCLUSION: It was concluded that, under simulated indoor competition environment, high HR values do not influence short distance shooting scores.

Objectively measured activity in 8-10-year-old Turkish children: relationship to health-related fitness.

BACKGROUND: No objective data regarding the physical activity (PA) levels of young Turkish children currently exist. Furthermore, whether habitual PA is associated with the components of health-related fitness among children is unclear. The aim of this study was to evaluate the patterns and levels of objectively measured PA in prepubertal Turkish children and its relationship with body fatness, aerobic and anaerobic fitness. METHODS: Eighty-nine 8-10-year-old children (47 boys and 42 girls) participated in this study. The intensity, duration and frequency of PA were assessed from 4 days of heart rate monitoring with 15 s sampling intervals. Body fatness was determined by measuring skinfold thickness. Anaerobic fitness was evaluated using the Wingate test. All the children performed the shuttle run test to assess aerobic fitness. RESULTS: The PA of boys was significantly higher than that of girls (P < 0.05). Gender difference is more marked for vigorous PA. Instead of sustained PA, short bouts of PA, lasting up to 1 min, were characteristic of PA patterns of children. The duration and frequency of PA were positively related to aerobic fitness and negatively related to fatness for both gender groups (P < 0.05). These relationships were more prominent for accumulated PA than for other measures of PA. No relationship was obtained between PA and anaerobic fitness in either gender group (P > 0.05). CONCLUSIONS: Intermittent, accumulated moderate intensity PA may be more important than sustained vigorous intensity PA in influencing children's fitness and fatness levels. Detailed studies are needed to clarify which dimension of PA is more beneficial for health-related fitness in children.

Metabolic demands of match performance in young soccer players.

The aim of the present study was to determine metabolic responses, movement patterns and distance covered at running speeds corresponding to fixed blood lactate concentrations (FBLs) in young soccer players during a match play. A further aim of the study was to evaluate the relationships between FBLs, maximal oxygen consumption (VO2max) and distance covered during a game. A multistage field test was administered to 32 players to determine FBLs and VO2max. Blood lactate (LA), heart rate (HR) and rate of perceived exertion (RPE) responses were obtained from 36 players during tournament matches filmed using six fixed cameras. Images were transferred to a computer, for calibration and synchronization. In all players, values for LA and HR were higher and RPE lower during the 1(st) half compared to the 2(nd) half of the matches (p < 0.01). Players in forward positions had higher LA levels than defenders, but HR and RPE values were similar between playing positions. Total distance and distance covered in jogging, low-moderate-high intensity running and low intensity sprint were higher during the 1(st) half (p < 0.01). In the 1(st) half, players also ran longer distances at FBLs [p<0.01; average running speed at 2mmol·L(-1) (FBL2): 3.32 ± 0.31m·s(-1) and average running speed at 4mmol·L(-1) (FBL4): 3.91 ± 0.25m·s(-1)]. There was a significant difference between playing positions in distance covered at different running speeds (p < 0.05). However, when distance covered was expressed as FBLs, the players ran similar distances. In addition, relationships between FBLs and total distance covered were significant (r = 0.482 to 0.570; p < 0.01). In conclusion, these findings demonstrated that young soccer players experienced higher internal load during the 1(st) half of a game compared to the 2(nd) half. Furthermore, although movement patterns of players differed between playing positions, all players experienced a similar physiological stress throughout the game. Finally, total distance covered was associated to fixed blood lactate concentrations during play. Key pointsBased on LA, HR and RPE responses, young top soccer players experienced a higher physiological stress during the 1(st) half of the matches compared to the 2(nd) half.Movement patterns differed in accordance with the players' positions but that all players experienced a similar physiological stress during match play.Approximately one quarter of total distance was covered at speeds that exceeded the 4 mmol·L(-1) fixed LA threshold.Total distance covered was influenced by running speeds at fixed lactate concentrations in young soccer players during match play.

Daily Physical Activity and Physical Fitness in 11-to 15-year-old Trained and Untrained Turkish Boys.

The aims of this study were to assess levels and patterns of physical activity (PA) in relation to age and regular sport activity, and to examine its relationship to physical fitness in trained and untrained boys. One hundred forty-seven 11-to 15- year-old boys (73 trained and 74 untrained) participated in this study. Trained boys, comprised of 26 soccer, 25 handball and 22 volleyball players, had been training regularly for at least one year. The intensity, duration and frequency of PA were assessed from four complete days of heart rate monitoring with 15-seconds sampling intervals. Aerobic fitness was assessed by determining peakVO2 with a portable breath-by-breath gas analyzer (Cosmed K4b(2)) and the running speeds at fixed lactate concentrations during an incremental running test. Anaerobic fitness was evalu-ated with the Wingate Anaerobic Test. Skinfold thicknesses from eight sites and Tanner stages of pubic hair were also obtained. Based on 15-s heart rate data, instead of continuous activity, multiple short bouts of moderate and vigorous PA, lasting up to one minute, were characteristic of daily PA patterns of both trained and untrained boys. PA levels of trained boys were higher than untrained boys (p < 0.01) and the levels of PA decreased with age and maturation in both groups (p < 0.05). Daily PA variables were related to body fatness in both groups (p < 0.05), but the relationships were not consistent in the trained group. Daily PA variables were also related to aerobic fitness in the untrained group (p < 0.05) and these relationships were somewhat better with vigorous PA, whereas in the trained group, none of the PA variables were related to any of the aerobic fitness indices (p > 0.05). No relationship was observed between PA variables and anaerobic fitness in either group (p> 0.05). It seems that such relationships may somewhat depend on the fitness level of the subjects. Key pointsPA levels of trained boys were higher than untrained boys and the levels of PA decreased with age and maturation in both groups.Based on the 15-s HR data, instead of continuous activity, multiple short bouts of moderate and vigorous PA, lasting up to one minute, were characteristic of daily PA patterns of both trained and untrained boys.Daily PA variables were related to aerobic fitness in the untrained group and these relationships were somewhat better with vigorous PA (>70% HRR), whereas in the trained group, none of the PA variables were related to any of the aerobic fitness indices.Neither peak nor mean power values were related to any of the daily PA variables in both trained and untrained groups.

Relationships among jumping performances and sprint parameters during maximum speed phase in sprinters.

The purpose of this study was to investigate the relationships among jumping performances and speed parameters during maximum speed phase in sprinters. Twenty-one men sprinters volunteered to participate at the beginning of the preparation training phase. All tests-including 100-m sprint running, squat jump (SJ), countermovement jump (CMJ), drop jump (DJ), 60-second repetitive jump (RJ), standing long jump (SLJ), standing triple jump (STJ), standing quintuple jump (SQJ), and standing 10-stride jump (STENJ)-were done on switching mats. Flight (FT) and contact times (CT) during the vertical jump tests and 10-m split times during 100-m sprint running were measured by a 2-channel precision timing system (PTS) connected to the mats. The trace marking method was used for measuring the stride length (SL) through 60 m in 100-m sprint running. Stride frequency (SF), maximum velocity (Vmax), jump height for all vertical jumps, and lower-body power in DJ and RJ were calculated. Statistical analysis showed that the highest significant correlation was found between Vmax and DJ height (r = 0.69; p < 0.05). However, the lowest significant correlation coefficient was found between SL at maximum velocity phase of sprint running and SJ (r = 0.39; p < 0.05). In conclusion, DJ height is demonstrated to be a more effective way to reflect Vmax during sprint running than the other vertical and horizontal jump tests at the beginning of the preparation training phase.

Power production among different sports with similar maximum strength.

The purpose of this study was to compare 1 repetition maximum (1RM) strength, maximum power (MP), linear momentum (Mp), and the loads of 1RM responsible for maximum power (MP%) and for linear momentum (Mp%) generated in explosive concentric bench press (CBP) motion among athletes from different sports. A total of 56 athletes (13 sprinters, 16 basketball players, 16 handball players, 5 volleyball players, and 6 bodybuilders) performed CBP in the loads of 40, 50, 60, 70, and 80% of 1RM with 1-minute rest intervals. MP and Mp were assessed during CBP by customized apparatus with 3 separate displacement transducers. There were no significant differences in MP, Mp, MP%, and Mp% among the athletes. The only significant positive correlation was found between overall 1RM and Mp for athletes (r = 0.37). In conclusion, long-term sport-specific training adaptations do not play a major role on speed-strength parameters in athletes with similar strength from different sports backgrounds.

Influence of Ramadan Fasting on Anaerobic Performance and Recovery Following Short time High Intensity Exercise.

The aim of this study was to investigate the effects of Ramadan fasting on anaerobic power and capacity and the removal rate of lactate after short time high intensity exercise in power athletes. Ten male elite power athletes (2 wrestlers, 7 sprinters and 1 thrower, aged 20-24 yr, mean age 22.30 ± 1.25 yr) participated in this study. The subjects were tested three times [3 days before the beginning of Ramadan (Pre-RF), the last 3 days of Ramadan (End-RF) and the last 3 days of the 4(th) week after the end of Ramadan (After-RF)]. Anaerobic power and capacity were measured by using the Wingate Anaerobic Test (WAnT) at Pre-RF, End-RF and After- RF. Capillary blood samples for lactate analyses and heart rate recordings were taken at rest, immediately after WAnT and throughout the recovery period. Repeated measures of ANOVA indicated that there were no significant changes in body weight, body mass index, fat free mass, percentage of body fat, daily sleeping time and daily caloric intake associated with Ramadan fasting. No significant changes were found in total body water either, but urinary density measured at End-RF was significantly higher than After-RF. Similarity among peak HR and peak LA values at Pre-RF, End- RF and After-RF demonstrated that cardiovascular and metabolic stress caused by WAnT was not affected by Ramadan fasting. In addition, no influence of Ramadan fasting on anaerobic power and capacity and removal rate of LA from blood following high intensity exercise was observed. The results of this study revealed that if strength-power training is performed regularly and daily food intake, body fluid balance and daily sleeping time are maintained as before Ramadan, Ramadan fasting will not have adverse effects on body composition, anaerobic power and capacity, and LA metabolism during and after high intensity exercise in power athletes. Key pointsNo significant changes were assessed on body composition, daily sleeping time and caloric intake, and body fluid balance in regularly trained power athletes during Ramadan fasting.Ramadan fasting has no adverse effect on power outputs of short time high intensity exercise.No influence of Ramadan fasting on LA metabolism during high intensity exercise and passive recovery in regularly trained power athletes.

[Training in children]. / Cocuk ve antrenman.

Early participation of children in elite sports and significant achievements at younger ages have brought about the need for longer training years and intensive training programmes for child athletes. However, the response of children to training loads presents some differences from those of adults owing to characteristics associated with growth and development. Considering the influences of growth and development and in consistent with diverse stages of child growth, the course of training is divided into several stages including participation, general involvement, special preparation, and elite performance, each of which is characterized by distinct responses depending on functional and biological features. This article reviews particular aspects of child training in relation to growth, endurance, sexual development and maturation, and psychosocial development.