Roland van den Tillaar

Changes in strength and power performance in elite senior female professional volleyball players during the in-season: a case study.

Marques, MC, van den Tillaar, R, Vescovi, JD, and González-Badillo, JJ. Changes in strength and power performance in elite senior female professional volleyball players during the in-season: a case study. J Strength Cond Res 22: 1147-1155, 2008-It is often recommended that in-season training programs aim to maintain muscular strength and power developed during the off-season. However, improvements in performance may be possible with a well-designed training regimen. The purpose of this case report is to describe the changes in physical performance after an in-season training regimen in professional female volleyball players in order to determine whether muscular strength and power might be improved. Apart from normal practice sessions, 10 elite female volleyball players completed 2 training sessions per week, which included both resistance training and plyometric exercises. Over the 12-week season, the athletes performed 3-4 sets of 3-8 repetitions for resistance and plyometric exercises during each training session. All sessions were supervised by one of the investigators as well as by the team head coach. Muscular strength and power were assessed before and after the 12-week training program using 4 repetition maximum bench press and parallel squat tests, an overhead medicine ball throw (BTd), as well as unloaded and loaded countermovement jumps (CMJs). Strength improved by 15% and 11.5% in the bench press and parallel squat, respectively (p < 0.0001). Distance in the BTd improved by 11.8% (p < 0.0001), whereas unloaded and loaded CMJ height increased between 3.8 and 11.2%. The current findings suggest that elite female volleyball players can improve strength and power during the competition season by implementing a well-designed training program that includes both resistance and plyometric exercises.

Effect of core stability training on throwing velocity in female handball players.

Saeterbakken, AH, van den Tillaar, R, and Seiler, S. Effect of core stability training on throwing velocity in female handball players. J Strength Cond Res 25(3): 712-718, 2011-The purpose was to study the effect of a sling exercise training (SET)-based core stability program on maximal throwing velocity among female handball players. Twenty-four female high-school handball players (16.6 ± 0.3 years, 63 ± 6 kg, and 169 ± 7 cm) participated and were initially divided into a SET training group (n = 14) and a control group (CON, n = 10). Both groups performed their regular handball training for 6 weeks. In addition, twice a week, the SET group performed a progressive core stability-training program consisting of 6 unstable closed kinetic chain exercises. Maximal throwing velocity was measured before and after the training period using photocells. Maximal throwing velocity significantly increased 4.9% from 17.9 ± 0.5 to 18.8 ± 0.4 m·s−1 in the SET group after the training period (p < 0.01), but was unchanged in the control group (17.1 ± 0.4 vs. 16.9 ± 0.4 m·s−1). These results suggest that core stability training using unstable, closed kinetic chain movements can significantly improve maximal throwing velocity. A stronger and more stable lumbopelvic-hip complex may contribute to higher rotational velocity in multisegmental movements. Strength coaches can incorporate exercises exposing the joints for destabilization force during training in closed kinetic chain exercises. This may encourage an effective neuromuscular pattern and increase force production and can improve a highly specific performance task such as throwing.

VELOCITY SPECIFICITY IN EARLY-PHASE SPRINT TRAINING

A comparison of resistance running, normal sprint running, and supramaximal running was performed. Nineteen young, generally well-trained subjects were divided into 3 training groups: resistance, normal, and supramaximal groups. Resistance and supramaximal training was done using a towing device, providing extra resistance or propulsion forces, resulting in running speed differences of about 3.3% (supramaximal) and 8.5% (resistance), compared to normal sprinting. The training period was 6 weeks, with 3 training sessions per week (5 sprint-runs over 22 m). Running times were measured using photocells, and average step length and cadence were recorded by digital video. A small (0.5%) but significant (p < 0.05) overall pre-post difference was found in running velocity, but the 3 groups changed differently over the running conditions. All individual subjects improved sprinting velocity most on the trained form, at 1–2% (p < 0.001), and thus, the principle of velocity specificity in sprint training was supported. This indicates that to obtain short-distance sprinting improvement in a short period of time, one may prefer normal sprinting over other training forms.

INSTRUCTIONS EMPHASIZING VELOCITY, ACCURACY, OR BOTH IN PERFORMANCE AND KINEMATICS OF OVERARM THROWING BY EXPERIENCED TEAM HANDBALL PLAYERS

On motor tasks like the overarm throw, velocity and accuracy are two important parameters of performance that may be incompatible and require different strategies in the execution of the motor task. The purpose was to investigate the effects of instruction (emphasizing velocity, accuracy, or both) on performance and kinematics of overarm throwing. Results for 9 experienced male team handball players (M age = 24 ± 2.2 yr.) showed type of instruction affected the maximal ball velocity. The difference in ball velocity reflected the significant difference in maximal linear velocity of the wrist, elbow, and hip segments together with their absolute timing before ball release. The subjects did not seem to change their throwing technique, i.e., the relative timing of movement initiation of the different body segments.

EFFECT OF DIFFERENT TRAINING PROGRAMS ON THE VELOCITY OF OVERARM THROWING: A BRIEF REVIEW

ABSTRACTThrowing velocity in overarm throwing is of major importance in sports like baseball, team handball, javelin, and water polo. The purpose of this literature review was to give an overview of the effect of different training programs on the throwing velocity in overarm throwing, provide a the

Match analysis of elite adolescent team handball players.

Chelly, MS, Hermassi, S, Aouadi, R, Khalifa, R, Van den Tillaar, R, Chamari, K, and Shephard, RJ. Match analysis of elite adolescent team handball players. J Strength Cond Res 25(9): 2410-2417, 2011—The purposes of this study were to examine the activity profile of elite adolescent players during regular team handball games and to compare the physical and motor performance of players between the first and second halves of a match. Activity patterns (video analysis) and heart-rate (HR) responses (telemetry) were monitored in top national-division adolescent players (18 men, aged 15.1 ± 0.6 years) throughout 6 regulation games (25-minute halves with a 10-minute interval). The total distance covered averaged 1,777 ± 264 m per game (7.4% less in the second than in the first half, p > 0.05). Players ran 170 ± 24 m at high intensity and 86 ± 12 m at maximal speed, with 32 ± 6 bouts of running (duration 2.3 ± 0.3 seconds) at speeds > 18 km·h−1; they stood still for 16% of the playing time. The mean HR during play was 172 ± 2 b·min−1 (82 ± 3% of maximal HR). Blood lactate concentrations at the end of the first and second halves were 9.7 ± 1.1 and 8.3 ± 0.9 mmol·L−1, respectively (difference p < 0.05). We conclude that adolescent handball players cover less distance and engage in fewer technical actions in the second half of a match. This indicates that team handball is physiologically very demanding. The practical implication is that coaches should seek to sustain performance in the second period of a game by modifying playing tactics and maximizing both aerobic and anaerobic fitness during training sessions.

Is there a proximal-to-distal sequence in overarm throwing in team handball?

Abstract Research examining the proximal-to-distal sequencing of segments of the body involved in overarm throwing has been equivocal: some studies have found support for the concept while others have not. The aim of the present study, therefore, was to determine if there is a proximal-to-distal sequence in the timing of the movements of joints and the distal endpoints of segments in overarm throwing. The three-dimensional kinematics of a penalty throw in experienced team handball players (n = 11) were recorded and analysed with regard to the timing of events. We analysed the timing of the maximal velocity of the distal endpoints of six segments and the maximal angular velocity in 11 joints, as well as the initiation of these joint movements. A temporal proximal-to-distal sequence was observed only for the initiation of the joint movements. No such sequence was found for maximal velocity of the joints and distal endpoints of segments.

Relationships Between Vertical Jump and Full Squat Power Outputs With Sprint Times in U21 Soccer Players

Relationships Between Vertical Jump and Full Squat Power Outputs With Sprint Times in U21 Soccer Players The aim of this study was to assess the relationship between power variables in the vertical jump and full squat with the sprint performance in soccer players. Fourteen under-21 soccer players were evaluated in two testing sessions separated by 7 days. In the first testing session, vertical jump height in countermovement was assessed, and power output for both loaded countermovement jump (CMJL) and full squat (FS) exercises in two progressive load tests. The second testing session included sprinting at 10, 20, and 30m (T10, T20, T30, T10-20, T10-30, T20-30). Power variables obtained in the loaded vertical jump with 20kg and full squat exercise with 70kg showed significant relationships with all split times (r=-0.56/-0.79; p≤ 0.01/0.01). The results suggest that power produced either with vertical jump or full squat exercises is an important factor to explain short sprint performance in soccer players. These findings might suggest that certain levels of neuromuscular activation are more related with sprint performance reflecting the greater suitability of loads against others for the improvement of short sprint ability in under-21 soccer players.

A Comparison of Successful and Unsuccessful Attempts in Maximal Bench Pressing

PURPOSE This study was designed to compare the differences in EMG and kinematics between successful and unsuccessful attempts in bench pressing at one repetition maximum (1RM) in recreational weight-trained subjects. We hypothesized that failure occurs during the sticking period (the period during which there is a temporary reduction in movement velocity). METHODS Eleven male subjects (age = 21.9 +/- 1.8 yr, mass = 80.0 +/- 11.2 kg, height = 1.79 +/- 0.08 m) with at least 1 yr of bench press training experience participated in this study. They performed attempts at 1RM and 1RM + 2.5 kg in bench press during which kinematics and muscle activity were recorded. One successful attempt and one unsuccessful attempt were used for further analysis. RESULTS Both attempts showed the same sticking period, but only half of the failures occurred during that period. The main differences in the kinematics occurred during the sticking period. Muscle activity, in contrast, showed the same pattern in both attempts and only differed during the downward and the start of the upward movement of the lift. CONCLUSIONS The sticking period occurs in both successful and unsuccessful attempts in maximal bench press. However, failure does not always occur during the sticking period.

The “sticking period” in a maximum bench press

Abstract The purpose of this study was to examine muscle activity and three-dimensional kinematics in the ascending phase of a successful one-repetition maximum attempt in bench press for 12 recreational weight-training athletes, with special attention to the sticking period. The sticking period was defined as the first period of deceleration of the upward movement (i.e. from the highest barbell velocity until the first local lowest barbell velocity). All participants showed a sticking period during the upward movement that started about 0.2 s after the initial upward movement, and lasted about 0.9 s. Electromyography revealed that the muscle activity of the prime movers changed significantly from the pre-sticking to the sticking and post-sticking periods. A possible mechanism for the existence of the sticking period is the diminishing potentiation of the contractile elements during the upward movement together with the limited activity of the pectoral and deltoid muscles during this period.