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Oliver Gonzalo-Skok, Julio Tous-Fajardo, Carlos Valero-Campo, César Berzosa, Ana Vanessa Bataller, José Luis Arjol-Serrano, Gerard Moras and Alberto Mendez-Villanueva

Purpose:

To analyze the effects of 2 different eccentric-overload training (EOT) programs, using a rotational conical pulley, on functional performance in team-sport players. A traditional movement paradigm (ie, squat) including several sets of 1 bilateral and vertical movement was compared with a novel paradigm including a different exercise in each set of unilateral and multi-directional movements.

Methods:

Forty-eight amateur or semiprofessional team-sport players were randomly assigned to an EOT program including either the same bilateral vertical (CBV, n = 24) movement (squat) or different unilateral multidirectional (VUMD, n = 24) movements. Training programs consisted of 6 sets of 1 exercise (CBV) or 1 set of 6 exercises (VUMD) × 6–10 repetitions with 3 min of passive recovery between sets and exercises, biweekly for 8 wk. Functional-performance assessment included several change-of-direction (COD) tests, a 25-m linear-sprint test, unilateral multidirectional jumping tests (ie, lateral, horizontal, and vertical), and a bilateral vertical-jump test.

Results:

Within-group analysis showed substantial improvements in all tests in both groups, with VUMD showing more robust adaptations in pooled COD tests and lateral/horizontal jumping, whereas the opposite occurred in CBV respecting linear sprinting and vertical jumping. Between-groups analyses showed substantially better results in lateral jumps (ES = 0.21), left-leg horizontal jump (ES = 0.35), and 10-m COD with right leg (ES = 0.42) in VUMD than in CBV. In contrast, left-leg countermovement jump (ES = 0.26) was possibly better in CBV than in VUMD.

Conclusions:

Eight weeks of EOT induced substantial improvements in functional-performance tests, although the force-vector application may play a key role to develop different and specific functional adaptations.

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Dean G. Higham, David B. Pyne, Judith M. Anson and Anthony Eddy

Although the characteristics of 15-a-side rugby union players have been well defined, there is little information on rugby sevens players.

Purpose:

The authors profiled the anthropometric, physiological, and performance qualities of elite-level rugby sevens players and quantified relationships between these characteristics.

Methods:

Eighteen male international rugby sevens players undertook anthropometric (body mass, height, sum of 7 skinfolds, lean-mass index), acceleration and speed (40-m sprint), muscle-power (vertical jump), repeatedsprint- ability (6 × 30-m sprint), and endurance (Yo-Yo Intermittent Recovery test and treadmill VO2max) testing. Associations between measurements were assessed by correlation analysis.

Results:

Rugby sevens players had anthropometric characteristics (body mass 89.7 ± 7.6 kg, height 1.83 ± 0.06 m, sum of 7 skinfolds 52.2 ± 11.5 mm; mean ± SD) similar to those of backs in international 15-player rugby union. Acceleration and speed (40-m sprint 5.11 ± 0.15 s), muscle-power (vertical jump 66 ± 7 cm), and endurance (VO2max 53.8 ± 3.4 mL · kg−1 · min−1 ) qualities were similar to, or better than, those of professional 15-a-side players. Coefficients of variation ranged from 2.5% to 22%. Relative VO2max was largely correlated with Yo-Yo distance (r = .60, .21−.82; 90% confidence interval) and moderately correlated with 40-m sprint time (r = −.46, −.75 to −.02) and repeated-sprint ability (r = −.38, −.72 to .09).

Conclusions:

International rugby sevens players require highly developed speed, power, and endurance to tolerate the demands of competition. The small between-athletes variability of characteristics in rugby sevens players highlights the need for relatively uniform physical and performance standards in contrast with 15-a-side players.

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Jason D. Vescovi, Teena M. Murray and Jaci L. VanHeest

Purpose:

The primary purpose of this study was to determine whether positional profiling is possible for elite ice hockey players by examining anthropometric characteristics and physiological performance. In addition, performance ranges and percentiles were determined for each position (forwards, defensemen, and goalkeepers) on all dependent variables.

Methods:

A retrospective, cross-sectional study design was used with performance data from ice hockey players (mean age = 18.0 ± 0.6 years) attending the 2001 (n = 74), 2002 (n = 84), and 2003 (n = 92) Combines. Four anthropometric characteristics and 12 performance tests were the dependent variables. A 3 × 3 (position × year) 2-way ANOVA was used to determine whether any significant interactions were present. No significant interactions were observed, so the data were collapsed over the 3-year period and positional characteristics were analyzed using a 1-way ANOVA.

Results:

Defenders were heavier and/or taller compared with the other 2 positions (P ≤ .01), whereas goalkeepers showed greater body-fat percentage compared with that of forwards (P = .001). It was found that goalkeepers had significantly lower strength measures for the upper body (P ≤ .043) and lower anaerobic capacity (P ≤ .039) values compared with at least one other position, but they had greater flexibility (P ≤ .013). No positional differences were observed for the broad jump, vertical jump, aerobic power, or curl-ups.

Conclusion:

The current findings provide evidence supporting the use of anthropometric measurements, upper body strength, and anaerobic capacity to effectively distinguish among positions for elite-level ice hockey players.

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Nuttaset Manimmanakorn, Jenny J. Ross, Apiwan Manimmanakorn, Samuel J.E. Lucas and Michael J. Hamlin

Purpose:

To compare whole-body vibration (WBV) with traditional recovery protocols after a high-intensity training bout.

Methods:

In a randomized crossover study, 16 athletes performed 6 × 30-s Wingate sprints before completing either an active recovery (10 min of cycling and stretching) or WBV for 10 min in a series of exercises on a vibration platform. Muscle hemodynamics (assessed via near-infrared spectroscopy) were measured before and during exercise and into the 10-min recovery period. Blood lactate concentration, vertical jump, quadriceps strength, flexibility, rating of perceived exertion (RPE), muscle soreness, and performance during a single 30-s Wingate test were assessed at baseline and 30 and 60 min postexercise. A subset of participants (n = 6) completed a 3rd identical trial (1 wk later) using a passive 10-min recovery period (sitting).

Results:

There were no clear effects between the recovery protocols for blood lactate concentration, quadriceps strength, jump height, flexibility, RPE, muscle soreness, or single Wingate performance across all measured recovery time points. However, the WBV recovery protocol substantially increased the tissue-oxygenation index compared with the active (11.2% ± 2.4% [mean ± 95% CI], effect size [ES] = 3.1, and –7.3% ± 4.1%, ES = –2.1 for the 10 min postexercise and postrecovery, respectively) and passive recovery conditions (4.1% ± 2.2%, ES = 1.3, 10 min postexercise only).

Conclusion:

Although WBV during recovery increased muscle oxygenation, it had little effect in improving subsequent performance compared with a normal active recovery.

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Andrew C. Fry, William J. Kraemer, Michael H. Stone, Beverly J. Warren, Jay T. Kearney, Carl M. Maresh, Cheryl A. Weseman and Steven J. Fleck

To examine the effects of 1 week of high volume weightlifting and amino acid supplementation, 28 elite junior male weightlifting received either amino acid (protein) or lactose (placebo) capsules using double-blind procedures. weightlifting test sessions were performed before and after 7 days of high volume training sessions. Serum concentrations of testosterone (Tes), cortisol (Cort), and growth hormone (GH) as well as whole blood iactate (HLa) were determined from blood draws. Lifting performance was not altered for either group after training, although vertical jump performance decreased for both groups. Both tests elicited significantly elevated exercise-induced hormonal and HLa concentrations. Significant decreases in postexercise hormonal and HLa concentrations from Test 1 to Test 2 were observed for both groups. Tes concentrations at 7 a.m. and preexercise decreased for both groups from Test 1 to Test 2, while the placebo group exhibited a decreased 7 a.m. Tes/ Cort. These data suggest that amino acid supplementation does not influence resting or exercise-induced hormonal responses to 1 week of high volume weight training, but endocrine responses did suggest an impending overtraining syndrome.

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Michael H. Stone, Kimberly Sanborn, Lucille L. Smith, Harold S. O'Bryant, Tommy Hoke, Alan C. Utter, Robert L. Johnson, Rhonda Boros, Joseph Hruby, Kyle C. Pierce, Margaret E. Stone and Brindley Garner

The purpose of this investigation was to study the efficacy of two dietary supplements on measures of body mass, body composition, and performance in 42 American football players. Group CM (n = 9) received creatine monohy-drate, Group P (n = 11) received calcium pyruvate. Group COM (n = 11) received a combination of calcium pyruvate (60%) and creatine (40%), and Group PL received a placebo. Tests were performed before (Tl) and after (T2) the 5-week supplementation period, during which the subjects continued their normal training schedules. Compared to P and PL. CM and COM showed significantly greater increases for body mass, lean body mass, 1 repetition maximum (RM) bench press, combined 1 RM squat and bench press, and static vertical jump (SVJ) power output. Peak rate of force development for SVJ was significantly greater for CM compared to P and PL. Creatine and the combination supplement enhanced training adaptations associated with body mass/composition, maximum strength, and SVJ; however, pyruvate supplementation alone was ineffective.

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Gal Ziv and Ronnie Lidor

The soccer goalkeeper (GK) is required to perform strenuous actions during practice sessions and actual games. One of the objectives of those professionals who work with GKs is to obtain relevant information on physical characteristics and physiological attributes of GKs, and to use it effectively when planning training programs for them. This article has three purposes: (a) to review a series of studies (n = 23) on physical characteristics, physiological attributes, and on-field performances of soccer GKs; (b) to outline a number of methodological limitations and research concerns associated with these studies; and (c) to suggest several practical recommendations for soccer coaches who work with GKs. Four main fndings emerged from our review: (a) professional adult GKs usually are over 180 cm tall and have a body mass of over 77 kg; (b) studies on agility and speed produced mixed results, with some showing similar values between GKs and field players and others showing reduced performance in GKs; (c) GKs usually have higher vertical jump values when compared with players playing the various field positions; (d) GKs cover approximately 5.5 km during a game, mostly by walking and jogging. Four methodological limitations and research concerns associated with the reviewed studies were discussed, among them the lack of a longitudinal approach and the lack of on-field performance studies. Three practical recommendations are made for coaches, one of which is that coaches should adopt a careful approach when selecting testing protocols and devices for the assessment of GKs’ physiological attributes.

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Jeremy Williams, Grant Abt and Andrew E. Kilding

Purpose:

To determine the effects of acute short-term creatine (Cr) supplementation on physical performance during a 90-min soccer-specific performance test.

Methods:

A double-blind, placebo-controlled experimental design was adopted during which 16 male amateur soccer players were required to consume 20 g/d Cr for 7 d or a placebo. A Ball-Sport Endurance and Speed Test (BEAST) comprising measures of aerobic (circuit time), speed (12- and 20-m sprint), and explosive-power (vertical jump) abilities performed over 90 min was performed presupplementation and postsupplementation.

Results:

Performance measures during the BEAST deteriorated during the second half relative to the first for both Cr (1.2–2.3%) and placebo (1.0–2.2%) groups, indicating a fatigue effect associated with the BEAST. However, no significant differences existed between groups, suggesting that Cr had no performance-enhancing effect or ability to offset fatigue. When effect sizes were considered, some measures (12-m sprint, –0.53 ± 0.69; 20-m sprint, –0.39 ± 0.59) showed a negative tendency, indicating chances of harm were greater than chances of benefit.

Conclusions:

Acute short-term Cr supplementation has no beneficial effect on physical measures obtained during a 90-min soccer-simulation test, thus bringing into question its potential as an effective ergogenic aid for soccer players.

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Bruno Marrier, Yann Le Meur, Julien Robineau, Mathieu Lacome, Anthony Couderc, Christophe Hausswirth, Julien Piscione and Jean-Benoît Morin

Purpose:

To compare the sensitivity of a sprint vs a countermovement-jump (CMJ) test after an intense training session in international rugby sevens players, as well as analyze the effects of fatigue on sprint acceleration.

Methods:

Thirteen international rugby sevens players completed two 30-m sprints and a set of 4 repetitions of CMJ before and after a highly demanding rugby sevens training session.

Results:

Change in CMJ height was unclear (–3.6%; ±90% confidence limits 11.9%. Chances of a true positive/trivial/negative change: 24/10/66%), while a very likely small increase in 30-m sprint time was observed (1.0%; ±0.7%, 96/3/1%). A very likely small decrease in the maximum horizontal theoretical velocity (V0) (–2.4; ±1.8%, 1/4/95%) was observed. A very large correlation (r = –.79 ± .23) between the variations of V0 and 30-m-sprint performance was also observed. Changes in 30-m sprint time were negatively and very largely correlated with the distance covered above the maximal aerobic speed (r = –.71 ± .32).

Conclusions:

The CMJ test appears to be less sensitive than the sprint test, which casts doubts on the usefulness of a vertical-jump test in sports such as rugby that mainly involve horizontal motions. The decline in sprint performance relates more to a decrease in velocity than in force capability and is correlated with the distance covered at high intensity.

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Catalina Fernández-Campos, Ana L. Dengo and José Moncada-Jiménez

To determine the acute effect of an energy drink (ED) on physical performance of professional female volleyball players. 19 females (age= 22.3 ± 4.9 yr.; height= 171.8 ± 9.4 cm; weight= 65.2 ± 10.1 kg) participated in a randomized, crossover, double-blind study to measure grip strength, vertical jump and anaerobic power in 3 different sessions (ED, placebo [PL] or no beverage [CTL]). For each session, participants arrived in a fasted state, consumed a standardized breakfast meal, and 1 hr later completed the 3 baseline performance tests without having ingested the beverage. After completing the premeasurements, the athletes drank 6 ml/kg of body weight of the ED or PL and in the CTL condition no beverage was consumed. Posttest measurements were taken 30 min after the ingestion of liquids. A 3 × 2 repeated-measures ANOVA revealed no significant within-session and measurement time interactions for each performance test. Regardless of the measurement time, right hand grip strength was significantly higher in the ED condition (34.6 ± 0.9 kg) compared with PL (33.4 ± 1.1 kg) and CTL (33.6 ± 1.0 kg) (p > 0.05). Regardless of the beverage ingested, averaged right hand grip strength, taking into account all 3 testing conditions, increased from pre to posttesting (Pre = 33.8 ± 0.9 kg vs. Post = 33.9 ± 1.0 kg; p = 0.029), as did the averaged fatigue index, obtained from the anaerobic power test (Pre = 65.9± 2.2% vs. Post = 68.7± 2.0%; p= 0.049). The acute ingestion of an ED did not improve physical performance of professional Costa Rican female volleyball players.