Jump peak power assessment through power prediction equations in different samples

The aim of this study was to describe the characteristics of jump capacity in a group of secondary school students and to develop 2 specific equations-applied to boys and girls, respectively, to estimate the jump power of secondary school students. Four hundred and fifty-six boys (age, 14.1 ± 0.8 years; mass, 61.9 ± 15.7 kg; height, 1.64 ± 0.10 m) and 465 girls (age, 14.1 ± 0.9 years; mass, 55.1 ± 10.0 kg; height, 1.58 ± 0.07 m), all of them secondary school students, volunteered to participate in this study. They performed a vertical jump test (Abalakov) on a force platform, and jump height and peak power were measured. Most importantly, peak power was also estimated through a series of previously established power equations. For the purpose of establishing statistically significant differences, a p value ≤ 0.05 was fixed. The equations proposed by Canavan and Vesconvi, and Harman were the most precise with respect to actual power, reaching a percentage of 1.9-2.1 and 3.6-4.1%, respectively. The equations by Sayers and Lara showed a greater difference in percentage (9.9-12.4 and 22.4-24.2%, respectively) with that of actual power. Similar results were not obtained in other studies, which means that a specific equation will be required according to the characteristics of the assessed sample. Two equations specifically addressed to secondary school students will be established in this article: boys: ([61.8 jump height (cm)] + [37.1 body mass (kg)] - 1,941.6); girls: ([31 jump height (cm)] + [45 body mass (kg)] - 1,045.4). Crossvalidation tests that were done to prove the validity of said equations showed positive results. Practical applications: Those teachers who wish to estimate the jump power of their pupils can use these equations and thereby calculate jump power by the indirect method from jump height and body mass index, without any need to use any expensive tools.     

Assessing lower-body peak power in elite rugby-union players

Resistance training at the load that maximizes peak power (Pmax) may produce greater increases in peak power than other loads. Pmax for lower-body lifts can occur with no loading but whether Pmax can be increased further with negative loading is unclear. The purpose of this investigation was therefore to determine lower-body Pmax (jump squat) using a spectrum of loads. Box squat 1 repetition maximum (1RM) was measured in 18 elite rugby-union players. Pmax was then determined using loads of -28 to 60%1RM. Elastic bands were used to unload body weight for negative loads. Jump squat Pmax occurred with no loading (body weight: 8,880 ± 2,186 W) in all but 2 subjects. There was a discontinuity in the power-load relationship for the jump squat, possibly because of the increased countermovement in the body weight jump. The self-selected depth (dip) before the propulsive phase of the jump was greater by 24 ± 11 to 40 ± 16% (moderate to large effect size) than all positive loads. These findings highlight methodological issues that need to be taken into consideration when comparing power outputs of loaded and unloaded jumps.     

Effects of complex training on explosive strength in adolescent male basketball players

The purpose of this study was to evaluate the effects of a complex training program, a combined practice of weight training and plyometrics, on explosive strength development of young basketball players. Twenty-five young male athletes, aged 14-15 years old, were assessed using squat jump (SJ), countermovement jump (CMJ), Abalakov test (ABA), depth jump (DJ), mechanical power (MP), and medicine ball throw (MBT), before and after a 10-week in-season training program. Both the control group (CG; n = 10) and the experimental group (EG; n = 15) kept up their regular sports practice; additionally, the EG performed 2 sessions per week of a complex training program. The EG significantly improved in the SJ, CMJ, ABA, and MBT values (p < 0.05). The CG significantly decreased the values (p < 0.05) of CMJ, ABA, and MP, while significantly increasing the MBT values (p < 0.05). Our results support the use of complex training to improve the upper and lower body explosivity levels in young basketball players. In conclusion, this study showed that more strength conditioning is needed during the sport practice season. Furthermore, we also conclude that complex training is a useful working tool for coaches, innovative in this strength-training domain, equally contributing to a better time-efficient training.     

Acute effects of static stretching on peak torque and mean power output in National Collegiate Athletic Association Division I women's basketball players

The purpose of this study was to examine the acute effects of static stretching on peak torque (PT) and mean power output (MP) during maximal, voluntary concentric isokinetic leg extensions at 60 and 300 degrees .s(-1) in National Collegiate Athletic Association Division I Women's Basketball players. Eleven members of a women's basketball team volunteered to perform maximal concentric isokinetic leg extensions at 60 and 300 degrees .s(-1) on a calibrated Biodex System 3 dynamometer. After the initial isokinetic testing, the dominant leg extensors were stretched using 1 unassisted and 3 assisted static stretching exercises. The poststretching isokinetic assessments were repeated at 5, 15, 30, and 45 minutes after the static stretching (post-5, post-15, post-30, and post-45). PT (N.m) and MP (W) were recorded by dynamometer software. The results indicated no stretching-related changes in PT (p = 0.161) or MP (p = 0.088) from pre- to poststretching for any of the testing intervals (post-5, post-15, post-30, and post-45). These findings indicated that the static stretching had no impact on PT or MP during maximal, voluntary concentric isokinetic muscle actions in collegiate women's basketball players. In conjunction with previous studies, these findings suggested that trained athletes may be less susceptible to the stretching-induced force deficit than untrained, nonathletes.     

Speed and agility of 12- and 14-year-old elite male basketball players

The aims of this study were (a) to identify and compare the speed and agility of 12- and 14-year-old elite male basketball players and (b) to investigate relations between speed and agility for both age groups of basketball players, to help coaches to improve their work. Sixty-four players aged 12 (M = 11.98 years, SD = 0.311) and 54 players aged 14 (M = 14.092 years, SD = 0.275) were tested. Three agility tests: agility t-test, zigzag agility drill, and agility run 4 × 15 m and 3 speed tests: 20-m run, 30-m run, and 50-m run were applied. Fourteen-year-old players achieved significantly better results in all speed and agility tests compared with 12-year-old players. The correlation coefficient (r = 0.81, p = 0.001) showed that 12-year-old players have the same ability in the 30- and 50-m runs. The other correlation coefficient (r = 0.59, p = 0.001) indicated that 20- and 30-m runs had inherently different qualities. The correlation coefficients between agility tests were <0.71, and therefore, each test in this group represents a specific task. In 14-year-old players, the correlation coefficients between the speed test results were <0.71. In contrast, the correlation coefficients between the agility tests were >0.71, which means that all the 3 tests represent the same quality. During the speed training of 12-year-old players, it is advisable to focus on shorter running distances, up to 30 m. During the agility training of the same players, it is useful to apply exercises with various complexities. In speed training of the 14-year-old players, the 30- and 50-m runs should be applied, and agility training should include more specific basketball movements and activities.     

Relation between maximal aerobic power and the ability to repeat sprints in young basketball players

The aim of this study was to examine the effects of maximal aerobic power (V(.-)O2max peak) level on the ability to repeat sprints (calculated as performance decrement and total sprinting time) in young basketball players. Subjects were 18 junior, well-trained basketball players (age, 16.8 +/- 1.2 years; height, 181.3 +/- 5.7 cm; body mass, 73 +/- 10 kg; V(.-)O2max peak, 59.6 +/- 6.9 ml x kg(-1) x min(-1)). Match analysis and time-motion analysis of competitive basketball games was used to devise a basketball-specific repeated-sprint ability protocol consisting of ten 15-m shuttle run sprints with 30 s of passive recovery. Pre, post, and post plus 3-minute blood lactate concentrations were 2.5 +/- 0.7, 13.6 +/- 3.1, and 14.2 +/- 3.5 mmol x L(-1), respectively. The mean fatigue index (FI) value was 3.4 +/- 2.3% (range, 1.1-9.1%). No significant correlations were found between V(.-)O2max peak and either FI or total sprint time. A negative correlation (r = -0.75, p = 0.01) was found between first-sprint time and FI. The results of this study showed that V(.-)O2max peak is not a predictor of repeated-sprint ability in young basketball players. The high blood lactate concentrations found at the end of the repeated-sprint ability protocol suggest its use for building lactate tolerance in conditioned basketball players.     

Effects of continuous and interval running training on serum growth and cortisol hormones in junior male basketball players

Effects of two different eight-week aerobic training programs consisting of continuous (CR) or extensive interval running (IR) on serum growth (GH) and cortisol hormones in 33 male basketball players aged 15-16 were assessed. The CR group ran 4.8 km and the IR group ran 4 x 1.2 km, using equal work-to-rest ratio, three times per week. Aerobic power scores of all subjects and anaerobic power marks of the training subjects increased (p<0.01). Upon exertion, though serum GH levels increased in both exercise groups (p<0.01) prior to and following training; cortisol levels increased only in the IR group prior to training, and in both exercise groups following training (p<0.05). Following the eight week period, resting cortisol levels rose in the training (p<0.05) and control (p<0.01) groups. To conclude, an 8-week training program consisting of continuous or extensive interval running has been effective on acute GH and cortisol secretion in 15-16 year-old male athletes.     

Body composition and peak aerobic power in male international level Hungarian athletes

Body size, physique, body composition and physiological performance of elite athletes are independent aspects, have aroused the interest of exercise scientists, but studies that combine these aspects in elite athletes are scarcely available. The aim of the present study was to describe the selected anthropometric and exercise physiological characteristics of some Hungarian top athletes. The investigated subjects were qualified Hungarian water polo players (n=25), paddlers (n=24) and modem pentathlonists (n=20), all of whom had been medalists at several continental and intercontinental competitions. The athletes' body composition was estimated by the Drinkwater-Ross (45) body mass fractionation technique. Peak physiological performance was estimated by graded exhausting spiroergometric treadmill exercise. Intergroup differences in mean height, body mass and body composition characteristics were significant at the 5% level of random error. By the results of spiroergometry, all the three groups compared could be qualified as physically excellently trained. The greatest oxygen uptake relative to body mass was found in the modern pentathlonists (73.22 ml x kg(-1) x min(-1)) and the lowest one (59.79) in the water polo players. The authors do not disregard the favourable effects of regular and adequate trainings in the development of the studied characteristics, but in their opinion the process of proper selection has been the most important factor that explains the observed significant intergroup differences.     

Profiling in basketball: physical and physiological characteristics of elite players

The purpose of this study was to describe structural and functional characteristics of elite Serbian basketball players and to evaluate whether players in different positional roles have different physical and physiological profiles. Five men's basketball teams participated in the study and competed in the professional First National League. Physiological measurements were taken of 60 players during the final week of their preparatory training for competition. According to positional roles, players were categorized as guards (n = 20), forwards (n = 20), and centers (n = 20). Guards were older (p < 0.01) and more experienced (p < 0.01) as compared with both forwards and centers. Centers were taller and heavier than guards and forwards (p < 0.01), whereas forwards had significantly higher height and weight than guards (p < 0.01). Centers had more body fat (p < 0.01) as compared with forwards and guards. Also, centers had significantly lower estimated VO(2)max values (p < 0.01) compared with forwards and guards. In addition, the highest heart rate frequencies during the last minute of the shuttle run test were lower in guards (p < 0.01) as compared with forwards and centers. Vertical jump power was significantly higher in centers (p < 0.01) as compared with guards. The results of the present study demonstrate that a strong relationship exists between body composition, aerobic fitness, anaerobic power, and positional roles in elite basketball.     

A caffeinated energy drink improves jump performance in adolescent basketball players

This study aimed at investigating the effects of a commercially available energy drink on shooting precision, jump performance and endurance capacity in young basketball players. Sixteen young basketball players (first division of a junior national league; 14.9 ± 0.8 years; 73.4 ± 12.4 kg; 182.3 ± 6.5 cm) volunteered to participate in the research. They ingested either (a) an energy drink that contained 3 mg of caffeine per kg of body weight or (b) a placebo energy drink with the same appearance and taste. After 60 min for caffeine absorption, they performed free throw shooting and three-point shooting tests. After that, participants performed a maximal countermovement jump (CMJ), a repeated maximal jumps test for 15 s (RJ-15), and the Yo–Yo intermittent recovery test level 1 (Yo–Yo IR1). Urine samples were obtained before and 30 min after testing. In comparison to the placebo, the ingestion of the caffeinated energy drink did not affect precision during the free throws (Caffeine = 70.7 ± 11.8 % vs placebo = 70.3 ± 11.0 %; P = 0.45), the three-point shooting test (39.9 ± 11.8 vs 38.1 ± 12.8 %; P = 0.33) or the distance covered in the Yo–Yo IR1 (2,000 ± 706 vs 1,925 ± 702 m; P = 0.19). However, the energy drink significantly increased jump height during the CMJ (38.3 ± 4.4 vs 37.5 ± 4.4 cm; P < 0.05) mean jump height during the RJ-15 (30.2 ± 3.6 vs 28.8 ± 3.4 cm; P < 0.05) and the excretion of urinary caffeine (1.2 ± 0.7 vs 0.1 ± 0.1 μg/mL; P < 0.05). The intake of a caffeine-containing energy drink (3 mg/kg body weight) increased jump performance although it did not affect basketball shooting precision.     

Handgrip strength and hand dimensions in young handball and basketball players

In handball and basketball the longer the finger length the better the accuracy of the shot or throw. All shots and throws are finished with the wrist and fingers. It can be proposed that athletes with longer fingers and greater hand surface parameters also probably have greater grip strength. The aim of this study was to investigate the influence of general body and hand-specific anthropometric dimensions on handgrip strength in boys participating in handball and basketball training. In total, 193 boys aged 10-17 years participated in this study. They were divided into 6 groups: 10-, 11-, 12-, 13-, 14-15-, and 16-17-year-olds. The body height and body mass were measured and body mass index was calculated as general anthropometric parameters. The outlines of the hands of the boys were drawn on paper with a thin marker. Three groups of hand anthropometric parameters were measured: 5 finger spans, 5 finger lengths, and 5 perimeters of the hand. Handgrip strength was measured on the dominant hand with a Lafayette dynamometer. As a rule, general anthropometric parameters determined the maximal handgrip strength more accurately than did specific hand anthropometric parameters. From the specific hand anthropometric parameters, finger lengths and perimeters of the hand significantly correlated with the maximal handgrip strength. In summary, fingers are the smallest, lightest parts of the motor apparatus, and, therefore, they represent the parts most easily deflected by force from the ball, but at the same time, finger control is especially important for the accuracy of different shots, both in handball and basketball. Thus, it is especially necessary to measure finger length and perimeters of the hand for practical reasons.     

Effect of recovery mode on repeated sprint ability in young basketball players

The aim of this study was to examine the effect of recovery mode on repeated sprint ability in young basketball players. Sixteen basketball players (age, 16.8 +/- 1.2 years; height, 181.3 +/- 5.7 cm; body mass, 73 +/- 10 kg; VO2max, 59.5 +/- 7.9 mL x kg(-1) x min(-1)) performed in random order over 2 separate occasions 2 repeated sprint ability protocols consisting of 10 x 30-m shuttle run sprints with 30 seconds of passive or active (running at 50% of maximal aerobic speed) recovery. Results showed that fatigue index (FI) during the active protocol was significantly greater than in the passive condition (5.05 +/- 2.4, and 3.39 +/- 2.3, respectively, p < 0.001). No significant association was found between VO2peak and FI and sprint total time (TT) in either repeated sprint protocols. Blood lactate concentration at 3 minutes post exercise was not significantly different between the 2 recovery conditions. The results of this study show that during repeated sprinting, passive recovery enabled better performance, reducing fatigue. Consequently, the use of passive recovery is advisable during competition in order to limit fatigue as a consequence of repeated high intensity exercise.     

Effects of basketball training on maximal oxygen uptake, muscle strength, and joint mobility in young basketball players

The purpose of this study was to examine the effects of prolonged basketball skills training on maximal aerobic power, isokinetic strength, joint mobility, and body fat percentage, in young basketball players, and controls of the same age. Twenty basketball players and 18 control boys participated in the study. Basketball players participated both in their school's physical education program and in a children's basketball team training program. Controls participated only in their school's physical education program. All subjects were tested every 6 months (18 months total, 11(1/2), 12, 12(1/2), 13 years old) for VO(2)max, peak torque values of the quadriceps and hamstrings at 180 and 300 degrees x s(-1) and range of motion of the knee and hip joints. Body fat percentage was assessed at the beginning and the end of the experimental period. Results showed that the basketball group had lower heart rate values in all ages and higher VO(2) values in the initial test compared with the control in submaximal intensity. The VO(2)max was altered in both groups on the final test, when compared to the initial test. However, the basketball group had a higher VO(2)max on each of the 6-month follow-up measurements, compared to the control group (p < 0.001). At the end of the 18-month follow-up period no significant differences were observed in isokinetic strength and joint mobility of the lower limbs between the 2 groups. On the contrary, the boys of the trained group had significantly lower percentage body fat values, compared to controls. In conclusion, regular basketball training increased aerobic power and decreased body fat percentage of prepubescent boys, while it did not affect muscle strength and joint mobility of the lower limbs. The major implication suggested by the findings of the present study is that, in order to improve the basic physical components, specific training procedures should be incorporated during the basketball training sessions. It is recommended that all children should be involved in some type of cardiovascular and resistance training program.     

Effects of 8-week in-season upper and lower limb heavy resistance training on the peak power, throwing velocity, and sprint performance of elite male handball players

The aims of this study were to test the potential of in-season heavy upper and lower limb strength training to enhance peak power output (Wpeak), vertical jump, and handball related field performance in elite male handball players who were apparently already well trained, and to assess any adverse effects on sprint velocity. Twenty-four competitors were divided randomly between a heavy resistance (HR) group (age 20 ± 0.7 years) and a control group (C; age 20 ± 0.1 years). Resistance training sessions were performed twice a week for 8 weeks. Performance was assessed before and after conditioning. Peak power (W(peak)) was determined by cycle ergometer; vertical squat jump (SJ) and countermovement jump (CMJ); video analyses assessed velocities during the first step (V(1S)), the first 5 m (V(5m)), and between 25 and 30 m (V(peak)) of a 30-m sprint. Upper limb bench press and pull-over exercises and lower limb back half squats were performed to 1-repetition maximum (1RM). Upper limb, leg, and thigh muscle volumes and mean thigh cross-sectional area (CSA) were assessed by anthropometry. W(peak) (W) for both limbs (p < 0.001), vertical jump height (p < 0.01 for both SJ and CMJ), 1RM (p < 0.001 for both upper and lower limbs) and sprint velocities (p < 0.01 for V(1S) and V(5m); p < 0.001 for V(peak)) improved in the HR group. Upper body, leg, and thigh muscle volumes and thigh CSA also increased significantly after strength training. We conclude that in-season biweekly heavy back half-squat, pull-over, and bench-press exercises can be commended to elite male handball players as improving many measures of handball-related performance without adverse effects upon speed of movement.     

Evaluation of autoantibodies against oxidized LDL and antioxidant status in top soccer and basketball players after 4 months of competition

Antioxidant status and titers of autoantibodies against oxidized low-density lipoproteins (ox-LDL-Ab) were investigated in top soccer (S; n = 21, age 24.6 +/- 4.3 years) and basketball (B; n 3,000 mIU/ml) in ox-LDL-Ab were found in half the players (12S and 4B) with a maximum reaching 6000 mIU/ml (normal range: 200-600 mIU/ml), showing an in vivo LDL oxidation. There was no correlation between ox-LDL-Ab titers and chlolesterol, LDL cholesterol, or antioxidant levels. Nevertheless, plasma vitamin C concentration was lower in athletes having high levels of ox-LDL-Ab when compared with those with normal levels (8.49 +/- 3.14 mirogram/ml vs. 10.39 +/- 2.55 microgram/ml), but this difference was not statistically significant. In conclusion, our data suggest that potential atherogenic and cardiovascular risks as reflected by high titers in ox-LDL-Ab may exist in some top athletes despite a nonaltered antioxidant status.     

The cost of energy and cardiovascular expenditure in basketball players during a game

Energy expenditure was evaluated for 6 Basket players while exercising on a cyclergometer. Oxygen consumption (VO2), pulmonary ventilation (VE), heart rate (HR), respiratory quotient (QR) and other parameters were estimated at various levels of load (25 Watt each step of 3 minutes duration), till to submaximal load of 175 Watt. The same subjects participate to a regular Basket game and their heart rate was continuously stored on a tape recorder (Holter). Arterial blood pressure was also taken whenever possible (timeout, etc). From the laboratory and field data, estimates were made for the oxygen consumption together with energy cost of the game. This can be assume a net value of 0.1339 Kcal X Kg-1 X min-1.     

Sprint,agility, strength and endurance capacity in wheelchair basketball players

The aims of the present study were, firstly, to determine the reliability and reproducibility of an agility T-test and Yo-Yo 10 m recovery test; and secondly, to analyse the physical characteristics measured by sprint, agility, strength and endurance field tests in wheelchair basketball (WB) players. 16 WB players (33.06 ± 7.36 years, 71.89 ± 21.71 kg and sitting body height 86.07 ± 6.82 cm) belonging to the national WB league participated in this study. Wheelchair sprint (5 and 20 m without ball, and 5 and 20 m with ball) agility (T-test and pick-up test) strength (handgrip and maximal pass) and endurance (Yo-Yo 10 m recovery test) were performed. T-test and Yo-Yo 10 m recovery test showed good reproducibility values (intraclass correlation coefficient, ICC = 0.74-0.94). The WB players’ results in 5 and 20 m sprints without a ball were 1.87 ± 0.21 s and 5.70 ± 0.43 s and with a ball 2.10 ± 0.30 s and 6.59 ± 0.61 s, being better than those reported in the literature. Regarding the pick-up test results (16.05 ± 0.52 s) and maximal pass (8.39 ± 1.77 m), players showed worse values than those obtained in elite players. The main contribution of the present study is the characterization of the physical performance profile of WB players using a field test battery. Furthermore, we demonstrated that the agility T-test and the aerobic Yo-Yo 10 m recovery test are reliable; consequently they may be appropriate instruments for measuring physical fitness in WB.     

The effects of resistance training on explosive strength indicators in adolescent basketball players

ABSTRACT: Santos, EJAM and Janeira, MAAS. The effects of resistance training on explosive strength indicators in adolescent basketball players. J Strength Cond Res 26(10): 2641-2647, 2012-The purpose of this study was to assess the effects of a lower- and upper-body 10-week in-season resistance training program on explosive strength development in young basketball players. Twenty-five adolescent male athletes, aged 14-15 years old, were randomly assigned to an experimental group (EG; n = 15) and a control group (CG; n = 10). The subjects were assessed at baseline and after training for squat jump (SJ), countermovement jump (CMJ), Abalakov test, drop jump, and seated medicine ball throw (MBT). The EG showed significant increases (p < 0.05) in all the variable scores. Conversely, the CG significantly decreased (p < 0.05) in SJ, CMJ, and Abalakov test scores and significantly increased in the results of MBT test (p < 0.05). The groups were similar on pretest, but significant differences (p < 0.05) occurred on posttest in all the variables. The results of this study show that a 10-week in-season resistance training program with moderate volume and intensity loads increased vertical jump and MBT performance in adolescent male basketball players. Coaches should know that such a short resistance training program specifically designed for young basketball players induce increased explosivity levels, which are essential to a better basketball performance, with no extra overload on adolescents' skeletal muscle development.     

Vertical jump, anaerobic power, and shooting accuracy are not altered 6 hours after strength training in collegiate women basketball players

We measured vertical jump, anaerobic power, and shooting accuracy in 18 Division I women basketball players (age 18-22 years) 6 hours following a morning strength training routine called a lift day (LD) and on a control day in which no strength training was performed. Subjects had been strength trained for 4 weeks prior to testing. The strength training session on lift day was a full-body workout and included 7 exercises performed in 3-6 sets at loads ranging from a 5 to 12 repetition maximum (RM). There were no significant differences in jump height with 2 legs (49.5 +/- 4.8 cm and 49.0 +/- 4.8 cm, LD and control, respectively), relative mean power output over 30 seconds on a Wingate bicycle test (6.4 +/- 0.8 W.kg(-1) and 6.6 +/- 0.7 W.kg(-1), LD and control, respectively), or shooting accuracy over 60 seconds (21.5 +/- 3.8 points/min and 21.3 +/- 4.1 points/min, LD and control, respectively). These data suggest that in collegiate women basketball players, a previous bout of strength training has no negative effect on vertical jump height, anaerobic power, or shooting accuracy.