bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Ramadan Intermittent Fasting on Sports Performance and Training: A Review
Authors: Anis Chaouachi , Leiper John B. , Nizar Souissi , Coutts Aaron J. , Karim Chamari
Published: August 2016

The month-long diurnal Ramadan fast imposes a major challenge to Islamic athletes. Sporting events are programmed throughout the year, with the result that training and competition are often scheduled during Ramadan. The small numbers of well-controlled studies that have examined the effects of Ramadan on athletic performance suggest that few aspects of physical fitness are negatively affected, and only modest decrements are observed. Whereas subjective feelings of fatigue and other mood indicators are often cited as implying additional stress on the athlete throughout Ramadan, most studies show these measures may not be reflected in decreases in performance. The development and early implementation of sensible eating and sleeping strategies can greatly alleviate the disruptions to training and competitiveness, thus allowing the athlete to perform at a high level while undertaking the religious intermittent fast. Nevertheless, further research is required to understand the mechanisms and energy pathways that allow athletes to maintain their performance capacities during Ramadan, and which factors are responsible for the observed decrements in performance of some individuals.
Effect of Two Different Training Programs with the Same Workload on Soccer Overhead Throwing Velocity
Authors: van den Tillaar Roland , Marques Mário C.
Published: August 2016

Purpose:

The purpose of this study was to determine whether two throwing programs, based upon velocity or resistance with the same workload, would enhance soccer overhead throwing velocity.

Methods:

Sports science students (n = 64, age 21.1 ± 2.1 y, mass 71.1 ± 11 kg, height 1.75 ± 0.09 m; mean ± SD) divided into two groups matched on performance, participated in the study. The resistance-training group trained overhead throwing with a 5-kg medicine ball for two sets of 8 reps per session, whereas a velocity training group threw four sets of 16 reps with a regular soccer ball. These training programs were matched on workload. Throwing performance with a soccer ball and a 5-kg medicine ball were tested before and after a training period of 6 wk with two sessions per week.

Results:

Both groups significantly increased the throwing velocity with the soccer ball (resistance-training group: 3.2% [1.0–5.5%)]; P = .003 and velocity-training group: 5.1% [2.6–7.7%]; P < .001), whereas no substantial changes were found for throwing with the 5-kg medicine ball after the training period. No substantial differences between the groups were found, which indicates that both forms of training increased the throwing velocity.

Conclusions:

It is concluded that both velocity and resistance throwing training programs after a short period of training with the same workload can increase throwing velocity and that workload is of importance in designing training programs and comparing them with each other.
Physiological Responses and Perceived Exertion During International Taekwondo Competition
Authors: Bridge Craig A. , Jones Michelle A. , Drust Barry
Published: August 2016

Purpose:

To investigate the physiological responses and perceived exertion during international Taekwondo competition.

Methods:

Eight male Taekwondo black belts (mean ± SD, age 22 ± 4 y, body mass 69.4 ± 13.4 kg, height 1.82 ± 0.10 m, competition experience 9 ± 5 y) took part in an international-level Taekwondo competition. Each combat included three 2-min rounds with 30 s of recovery between each round. Heart rate (HR) was recorded at 5-s intervals during each combat. Capillary blood lactate samples were taken from the fingertip 1 min before competition, directly after each round and 1 min after competition. Competitors’ rating of perceived exertion (RPE) was recorded for each round using Borg’s 6-to-20 scale.

Results:

HR (round 1: 175 ± 15 to round 3: 187 ± 8 beats·min−1; P < .05), percentage of HR maximum (round 1: 89 ± 8 to round 3: 96 ± 5% HRmax; P < .05), blood lactate (round 1: 7.5 ± 1.6 to round 3: 11.9 ± 2.1 mmol·L-1; P < .05) and RPE (round 1: 11 ± 2 to round 3: 14 ± 2; P < .05; mean ± SD) increased significantly across rounds.

Conclusions:

International-level Taekwondo competition elicited near-maximal cardiovascular responses, high blood lactate concentrations, and increases in competitors' RPE across combat. Training should therefore include exercise bouts that sufficiently stimulate both aerobic and anaerobic metabolism.
Effects of SAQ Training and Small-Sided Games on Neuromuscular Functioning in Untrained Subjects
Authors: Polman Remco , Bloomfield Jonathan , Edwards Andrew
Published: August 2016

Purpose:

The main objective of this study was to investigate the efficacy of both programmed (speed, agility, and quickness; SAQ) and random (small-sided games; SSG) conditioning methods on selected neuromuscular and physical performance variables.

Methods:

Twenty volunteers (21.1 ± 4.0 y, 1.71 ± 0.09 m, 66.7 ± 9.9 kg; mean ± SD) completed the study. The study design used two physically challenging periodized experimental conditions (SAQ and SSG conditions) and a non exercise control condition (CON). Participants engaged in 12.2 ± 2.1 h of directed physical conditioning. All participants had at least 24 h of recovery between conditioning sessions, and each 1-h session included 15 min of general warm-up and a 45-min exercise session. Participants completed a battery of tests (15-m sprint, isokinetic flexion/extension, depth jump) before and following the training program.

Results:

There was a 6.9% (95% CI: -4.4 to 18.3) greater improvement in 5-m acceleration time and 4.3% (95% CI: -0.9 to 9.5) in 15-m mean running velocity time for the SAQ group compared with the SSG group. In addition, increases in maximal isokinetic concentric strength for both the flexor and extensor muscles, with the exception of 180 °/s flexion, were greater in the SAQ than SSG condition. The SAQ group also showed 19.5% (95% CI: -11.2 to 50.2) greater gain in reactive strength (contact time depth jump) and 53.8% (95% CI: 11.2 to 98.6) in mean gastrocnemius medialis activity in comparison with SSG.

Conclusions:

SAQ training should benefit the physical conditioning programs of novice players performing invasion games.
Effects of Shoe Cleat Position on Physiology and Performance of Competitive Cyclists
Authors: Paton Carl D.
Published: August 2016

Purpose:

Aerobic economy is an important factor that affects the performance of competitive cyclists. It has been suggested that placing the foot more anteriorly on the bicycle pedals may improve economy over the traditional foot position by improving pedaling efficiency. The current study examines the effects of changing the anterior-posterior pedal foot position on the physiology and performance of well-trained cyclists.

Methods:

In a crossover study, 10 competitive cyclists completed two maximal incremental and two submaximal tests in either their preferred (control) or a forward (arch) foot position. Maximum oxygen consumption and peak power output were determined from the incremental tests for both foot positions. On two further occasions, cyclists also completed a two-part 60-min submaximal test that required them to maintain a constant power output (equivalent to 60% of their incremental peak power) for 30 min, during which respiratory and blood lactate samples were taken at predetermined intervals. Thereafter, subjects completed a 30-min self-paced maximal effort time trial.

Results:

Relative to the control, the mean changes (±90% confidence limits) in the arch condition were as follows: maximum oxygen consumption, -0.5% (±2.0%); incremental peak power output, -0.8% (±1.3%); steady-state oxygen consumption at 60%, -2.4% (±1.1%); steady-state heart rate 60%, 0.4% (±1.7%); lactate concentration 60%, 8.7% (±14.4%); and mean time trial power, -1.5% (±2.9%).

Conclusions:

We conclude that there was no substantial physiological or performance advantage in this group using an arch-cleat shoe position in comparison with a cyclist’s normal preferred condition.
Effects of Acute Multinutrient Supplementation on Rugby Union Game Performance and Recovery
Authors: Minett Geoff , Duffield Rob , Bird Stephen P.
Published: August 2016

Purpose:

To investigate the effects of an acute multinutrient supplement on game-based running performance, peak power output, anaerobic by-products, hormonal profiles, markers of muscle damage, and perceived muscular soreness before, immediately after, and 24 h following competitive rugby union games.

Methods:

Twelve male rugby union players ingested either a comprehensive multinutrient supplement (SUPP), [RE-ACTIVATE:01], or a placebo (PL) for 5 d. Participants then performed a competitive rugby union game (with global positioning system tracking), with associated blood draws and vertical jump assessments pre, immediately post and 24 h following competition.

Results:

SUPP ingestion resulted in moderate to large effects for augmented 1st half very high intensity running (VHIR) mean speed (5.9 ± 0.4 vs 4.8 ± 2.3 m·min−1; d = 0.93). Further, moderate increases in 2nd half VHIR distance (137 ± 119 vs 83 ± 89 m; d = 0.73) and VHIR mean speed (5.9 ± 0.6 v 5.3 ± 1.7 m·min−1; d = 0.56) in SUPP condition were also apparent. Postgame aspartate aminotransferase (AST; 44.1 ± 11.8 vs 37.0 ± 3.2 UL; d = 1.16) and creatine kinase (CK; 882 ± 472 vs. 645 ± 123 UL; d = 0.97) measures demonstrated increased values in the SUPP condition, while AST and CK values correlated with 2nd half VHIR distance (r = −0.71 and r = −0.76 respectively). Elevated C-reactive protein (CRP) was observed postgame in both conditions; however, it was significantly blunted with SUPP (P = .05).

Conclusions:

These findings suggest SUPP may assist in the maintenance of VHIR during rugby union games, possibly via the buffering qualities of SUPP ingredients. However, correlations between increased work completed at very high intensities and muscular degradation in SUPP conditions, may mask any anticatabolic properties of the supplement.
The Effect of Recovery Time on Strength Performance Following a High-Intensity Bench Press Workout in Males and Females
Authors: Judge Lawrence W. , Burke Jeanmarie R.
Published: August 2016

Purpose:

To determine the effects of training sessions, involving high-resistance, low-repetition bench press exercise, on strength recovery patterns, as a function of gender and training background.

Methods:

The subjects were 12 athletes (6 males and 6 females) and age-matched college students of both genders (4 males and 4 females). The subjects completed a 3-wk resistance training program involving a bench press exercise, 3 d/wk, to become familiar with the testing procedure. After the completion of the resistance training program, the subjects, on three consecutive weeks, participated in two testing sessions per week, baseline session and recovery session. During the testing sessions, subjects performed fve sets of the bench press exercise at 50% to 100% of perceived fve repetition maximum (5-RM). Following the weekly baseline sessions, subjects rested during a 4-, 24-, or 48-h recovery period. Strength measurements were estimates of one repetition maximum (1-RM), using equivalent percentages for the number of repetitions completed by the subject at the perceived 5-RM effort of the bench press exercise.

Results:

The full-factorial ANOVA model revealed a Gender by Recovery Period by Testing Session interaction effect, F(2, 32) = 10.65; P < .05. Among male subjects, decreases in estimated 1-RM were detected at the 4- and 24-h recovery times. There were no differences in muscle strength among the female subjects, regardless of recovery time.

Conclusions:

For bench press exercises, using different recovery times of 48 h for males and 4 h for females may optimize strength development as a function of gender.
World Records: How Much Athlete? How Much Technology?
Authors: de Koning Jos J.
Published: August 2016

The quality of performance during international competitions such as the Olympic Games and various world championships is often judged by the number of world records attained. The simple fact that world records continue to improve is evidence that sports performance is progressing. Does this also mean that athletes are improving? Is the continual progression of world-record performances evidence that contemporary athletes are superior to the athletes who performed in the past? Technological developments may obscure insight into the athletic enhancement made by athletes over the years. This commentary tries to separate technological and athletic enhancement in the progression of world records by the use of a power balance model.
Are Oxygen Uptake Kinetics Modified When Using a Respiratory Snorkel?
Authors: Reis Joana F. , Millet Gregoire P. , Malatesta Davide , Roels Belle , Borrani Fabio , Vleck Veronica E. , Alves Francisco B.
Published: August 2016

Purpose:

The aim of this study was to compare VO2 kinetics during constant power cycle exercise measured using a conventional facemask (CM) or a respiratory snorkel (RS) designed for breath-by-breath analysis in swimming.

Methods:

VO2 kinetics parameters—obtained using CM or RS, in randomized counterbalanced order—were compared in 10 trained triathletes performing two submaximal heavy-intensity cycling square-wave transitions. These VO2 kinetics parameters (ie, time delay: td1, td2; time constant: τ1, τ2; amplitude: A1, A2, for the primary phase and slow component, respectively) were modeled using a double exponential function. In the case of the RS data, this model incorporated an individually determined snorkel delay (ISD).

Results:

Only td1 (8.9 ± 3.0 vs 13.8 ± 1.8 s, P < .01) differed between CM and RS, whereas all other parameters were not different (τ1 = 24.7 ± 7.6 vs 21.1 ± 6.3 s; A1 = 39.4 ± 5.3 vs 36.8 ± 5.1 mL·min−1·kg−1; td = 107.5 ± 87.4 vs 183.5 ± 75.9 s; A2' (relevant slow component amplitude) = 2.6 ± 2.4 vs 3.1 ± 2.6 mL·min−1·kg−1 for CM and RS, respectively).

Conclusions:

Although there can be a small mixture of breaths allowed by the volume of the snorkel in the transition to exercise, this does not appear to significantly influence the results. Therefore, given the use of an ISD, the RS is a valid instrument for the determination of VO2 kinetics within submaximal exercise.
Physiological Responses to Ergometer and On-Water Incremental Rowing Tests
Authors: Vogler Andrew J. , Rice Anthony J. , Gore Christopher J.
Published: August 2016

Purpose:

This study evaluated the validity of ergometer tests against the criterion of on-water rowing and determined the reliability of feld measurements by comparing results between ergometer (ERG) and on-water (OW) tests.

Methods:

Seven male rowers completed incremental tests on a Concept2 rowing ergometer and in a single scull. Average power output, oxygen consumption (VO2), heart rate (HR), blood lactate concentration (BLa) and distance completed were measured during each ERG and OW workload.

Data treatment:

Linear regression between power output and HR, BLa, VO2 and distance allowed submaximal results to be compared between ERG and OW tests at equivalent intensities based on five standard power outputs. Submaximal results were analyzed using repeated measure factorial ANOVAs and maximal data used dependent t tests (P < .05), the magnitude of differences were also classified using effect size analyses. The reliability of repeated measurements was established using Typical Error.

Results:

Differences between ERG and OW submaximal results were not statistically significant for power output, HR, BLa, and VO2, but distance completed (P < .001) was higher during the ERG test. However, the magnitude of physiological response differences between the ERG and OW tests varied between individuals. Mean HR at anaerobic threshold showed good agreement between both tests (r = .81), but the standard error of the estimate was 9 beats per minute.

Conclusions:

Individual variation in physiological response differences between ERG and OW tests meant that training intensity recommendations from the ERG test were not applicable to on-water training for some rowers, but provided appropriate prescriptions for most athletes.
Measuring Training Load in Sports
Authors: Lambert Michael Ian , Borresen Jill
Published: August 2016

The principle of training can be reduced to a simple “dose-response” relationship. The “response” in this relationship can be measured as a change in performance or the adaptation of a physiological system. The “dose” of training, or physiological stress associated with the training load, is more difficult to measure as there is no absolute “gold standard” which can be used in the field, making it difficult to validate procedures. Attempts have been made to use heart rate as a marker of intensity during training, but the theoretical attractiveness of this method is not supported by the accuracy and the practicality of using this method during training or competition. The session RPE, based on the product of training duration and perceived intensity is more practical and can be used in a variety of sports. However, the score depends on a subjective assessment, and the intersubject comparisons may be inaccurate. The demands of different sports vary and therefore the methods of assessing training need to vary accordingly. The time has come to reach consensus on assessing training accurately in different sports. There is a precedent for this consensus approach with scientists having already done so for the assessment of physical activity, and for defining injuries in rugby, football and cricket. Standardizing these methods has resulted in the quality of research in these areas increasing exponentially.
Hypoxia Increases Muscle Hypertrophy Induced by Resistance Training
Authors: Nishimura Akinobu , Sugita Masaaki , Kato Ko , Fukuda Aki , Sudo Akihiro , Uchida Atsumasa
Published: August 2016

Purpose:

Recent studies have shown that low-intensity resistance training with vascular occlusion (kaatsu training) induces muscle hypertrophy. A local hypoxic environment facilitates muscle hypertrophy during kaatsu training. We postulated that muscle hypertrophy can be more efficiently induced by placing the entire body in a hypoxic environment to induce muscle hypoxia followed by resistance training.

Methods:

Fourteen male university students were randomly assigned to hypoxia (Hyp) and normoxia (Norm) groups (n = 7 per group). Each training session proceeded at an exercise intensity of 70% of 1 repetition maximum (RM), and comprised four sets of 10 repetitions of elbow extension and fexion. Students exercised twice weekly for 6 wk and then muscle hypertrophy was assessed by magnetic resonance imaging and muscle strength was evaluated based on 1RM.

Results:

Muscle hypertrophy was significantly greater for the Hyp-Ex (exercised fexor of the hypoxia group) than for the Hyp-N (nonexercised fexor of the hypoxia group) or Norm-Ex fexor (P < .05, Bonferroni correction). Muscle hypertrophy was significantly greater for the Hyp-Ex than the Hyp-N extensor. Muscle strength was significantly increased early (by week 3) in the Hyp-Ex, but not in the Norm-Ex group.

Conclusion:

This study suggests that resistance training under hypoxic conditions improves muscle strength and induces muscle hypertrophy faster than under normoxic conditions, thus representing a promising new training technique.
Blood Lactate Concentration and Clearance in Elite Swimmers During Competition
Authors: Vescovi Jason D. , Falenchuk Olesya , Wells Greg D.
Published: August 2016

Purpose:

Blood lactate concentration, [BLa], after swimming events might be influenced by demographic features and characteristics of the swim race, whereas active recovery enhances blood lactate removal. Our aims were to (1) examine how sex, age, race distance, and swim stroke influenced [BLa] after competitive swimming events and (2) develop a practical model based on recovery swim distance to optimize blood lactate removal.

Methods:

We retrospectively analyzed postrace [BLa] from 100 swimmers who competed in the finals at the Canadian Swim Championships. [BLa] was also assessed repeatedly during the active recovery. Generalized estimating equations were used to evaluate the relationship between postrace [BLa] with independent variables.

Results:

Postrace [BLa] was highest following 100–200 m events and lowest after 50 and 1500 m races. A sex effect for postrace [BLa] was observed only for freestyle events. There was a negligible effect of age on postrace [BLa]. A model was developed to estimate an expected change in [BLa] during active recovery (male = 0; female = 1): [BLa] change after active recovery = –3.374 + (1.162 × sex) + (0.789 × postrace [BLa]) + (0.003 × active recovery distance).

Conclusions:

These findings indicate that swimmers competing at an elite standard display similar postrace [BLa] and that there is little effect of age on postrace [BLa] in competitive swimmers aged 14 to 29 y.
Application of Critical Power in Sport
Authors: Vanhatalo Anni , Jones Andrew M. , Burnley Mark
Published: August 2016

The critical power (CP) is mathematically defined as the power-asymptote of the hyperbolic relationship between power output and time-to-exhaustion. Physiologically, the CP represents the boundary between the steady-state and nonsteady state exercise intensity domains and therefore may provide a more meaningful index of performance than other well-known landmarks of aerobic fitness such as the lactate threshold and the maximal O2 uptake. Despite the potential importance to sports performance, the CP is often misinterpreted as a purely mathematical construct which lacks physiological meaning and only in recent years has this concept begun to emerge as valid and useful technique for monitoring endurance fitness. This commentary defines the basic principles of the CP concept, outlines its importance to high-intensity exercise performance, and provides an overview of the current methods available for its assessment. Interventions including training, pacing and prior exercise can be used to alter the parameters of the power-time relationship. A future challenge lies in optimizing such interventions in order to positively affect the parameters of the power-time relationship and thereby enhance sports performance in specific events.
Rate of Muscle Activation in Power-and Endurance-Trained Boys
Authors: Mitchell Cameron , Cohen Rotem , Dotan Raffy , Gabriel David , Klentrou Panagiota , Falk Bareket
Published: August 2016

Previous studies in adults have demonstrated power athletes as having greater muscle force and muscle activation than nonathletes. Findings on endurance athletes are scarce and inconsistent. No comparable data on child athletes exist.

Purpose:

This study compared peak torque (Tq), peak rate of torque development (RTD), and rate of muscle activation (EMG rise, Q30), in isometric knee extension (KE) and fexion (KF), in pre- and early-pubertal power- and endurance-trained boys vs minimally active nonathletes.

Methods:

Nine gymnasts, 12 swimmers, and 18 nonathletes (7–12 y), performed fast, maximal isometric KE and KF. Values for Tq, RTD, electromechanical delay (EMD), and Q30 were calculated from averaged torque and surface EMG traces.

Results:

No group differences were observed in Tq, normalized for muscle cross-sectional area. The Tq-normalized KE RTD was highest in power athletes (6.2 ± 1.9, 4.7 ± 1.2, 5.0 ± 1.5 N·m·s–1, for power, endurance, and nonathletes, respectively), whereas no group differences were observed for KF. The KE Q30 was significantly greater in power athletes, both in absolute terms and relative to peak EMG amplitude (9.8 ± 7.0, 5.9 ± 4.2, 4.4 ± 2.2 mV·ms and 1.7 ± 0.8, 1.1 ± 0.6, 0.9 ± 0.5 (mV·ms)/(mV) for power, endurance, and nonathletes, respectively), with no group differences in KF. The KE EMD tended to be shorter (P = .07) in power athletes during KE (71.0 ± 24.1, 87.8 ± 18.0, 88.4 ± 27.8 ms, for power, endurance, and nonathletes), with no group differences in KF.

Conclusions:

Pre- and early-pubertal power athletes have enhanced rate of muscle activation in specifically trained muscles compared with controls or endurance athletes, suggesting that specific training can result in muscle activation-pattern changes before the onset of puberty.
The Construct Validity of Session RPE During an Intensive Camp in Young Male Taekwondo Athletes
Authors: Haddad Monoem , Chaouachi Anis , Castagna Carlo , Wong Del P. , Behm David G. , Chamari Karim
Published: August 2016

Purpose:

The session rating of perceived exertion (RPE) is a practical and non-invasive method that allows a quantification of the internal training load (TL) in individual and team sports, but no study has investigated its construct validity in martial arts. Therefore, the purpose of this study was to examine the convergent validity between the session-RPE method and two objective HR-based methods for quantifying the similar TL during a high-TL camp in young Taekwondo (TKD) athletes.

Methods:

Ten young TKD athletes (mean ± SD: age, 13.1 ± 2.4 y; body mass, 46.1 ± 12.7 kg; height, 1.53 ± 0.15 m; maximum heart rate (HRmax), 201.0 ± 8.2 bpm) participated in this study. During the training period, subjects performed 35 TKD training sessions, including two formal competitions during which RPE and HR were recorded and analyzed (308 individual training sessions). Correlation analysis was used to evaluate the convergent validity between session-RPE method and the two commonly used HR-based methods for assessing TL in a variety of training modes.

Results:

Significant relationships were found between individual session-RPE and all the HR-based TLs (r values from 0.55 to 0.90; P < .001). Significant correlations were observed in all mode of exercises practiced in TKD.

Conclusions:

This study shows that session-RPE can be considered as a valid method to assess TL in TKD.
Seasonal Monitoring of Sprint and Jump Performance in a Soccer Youth Academy
Authors: Williams Craig A. , Oliver Jon L. , Faulkner James
Published: August 2016

Purpose:

The aim of the study was to longitudinally assess speed and jump performance characteristics of youth football players over a 3 y period.

Methods:

Two hundred players across five age squads (U12–U16) from an English Football League academy participated. Sprint performance (10 and 30 m) and countermove-ment jump height were assessed at 6 mo intervals. Pairwise analyses determined the level of change in performance between consecutive intervals.

Results:

Sprint performance changes tended to be greatest during the early teenage years, with observed changes exceeding the smallest worthwhile effect (1.0% for 10 and 30 m sprints). Changes in jump performance were above the smallest worthwhile effect of 1.8% for all but one interval. Large individual variability in the magnitude of change in sprint and jump performance, perhaps due to the confounding effect of growth and maturation, revealed few significant differences across the 6 mo intervals. Cumulative changes in performance demonstrated strong linear relationships, with a yearly rate of change of 6.9% for jump height, and 3.1 and 2.7% for 10 m and 30 m sprint time respectively. The magnitude of change in performance tended not to differ from one interval to another.

Conclusions:

The results of this study may primarily be used to monitor and predict the rate of progression of youth football players. In addition, these results may be used as a benchmark to evaluate the effectiveness of a current training program.
The Reliability of MinimaxX Accelerometers for Measuring Physical Activity in Australian Football
Authors: Boyd Luke J. , Ball Kevin , Aughey Robert J.
Published: August 2016

Purpose:

To assess the reliability of triaxial accelerometers as a measure of physical activity in team sports.

Methods:

Eight accelerometers (MinimaxX 2.0, Catapult, Australia) were attached to a hydraulic universal testing machine (Instron 8501) and oscillated over two protocols (0.5 g and 3.0 g) to assess within- and between-device reliability. A static assessment was also conducted. Secondly, 10 players were instrumented with two accelerometers during Australian football matches. The vector magnitude was calculated, expressed as Player load and assessed for reliability using typical error (TE) ± 90% confidence intervals (CI), and expressed as a coefficient of variation (CV%). The smallest worthwhile difference (SWD) in Player load was calculated to determine if the device was capable of detecting differences in physical activity.

Results:

Laboratory: Within- (Dynamic: CV 0.91 to 1.05%; Static: CV 1.01%) and between-device (Dynamic: CV 1.02 to 1.04%; Static: CV 1.10%) reliability was acceptable across each test. Field: The between-device reliability of accelerometers during Australian football matches was also acceptable (CV 1.9%). The SWD was 5.88%.

Conclusions:

The reliability of the MinimaxX accelerometer is acceptable both within and between devices under controlled laboratory conditions, and between devices during field testing. MinimaxX accelerometers can be confidently utilized as a reliable tool to measure physical activity in team sports across multiple players and repeated bouts of activity. The noise (CV%) of Player load was lower than the signal (SWD), suggesting that accelerometers can detect changes or differences in physical activity during Australian football.
Effect of the Number of Ball Contacts Within Bouts of 4 vs. 4 Small-Sided Soccer Games
Authors: Dellal Alexandre , Lago-Penas Carlos , Wong Del P. , Chamari Karim
Published: August 2016

Purpose:

The aim of this study was to examine the influence of the number of ball touches authorized per possession on the physical demands, technical performances and physiological responses throughout the bouts within 4 vs. 4 soccer small-sided games (SSGs).

Methods:

Twenty international soccer players (27.4 ± 1.5 y, 180.6 ± 2.3 cm, 79.2 ± 4.2 kg, body fat 12.7 ± 1.2%) performed three different 4 vs. 4 SSGs (4 × 4 min) in which the number of ball touches authorized per possession was manipulated (1 touch = 1T; 2 touches = 2T; Free Play = FP). The SSGs were divided in 4 bouts (B1, B2, B3 and B4) separated by 3 min of passive recovery. The physical performances, technical activities, heart rate responses, blood lactate and RPE were analyzed.

Results:

The FP rule presented greater number of duels, induced the lowest decreases of the sprint and high-intensity performances, and affected less the technical actions (successful passes and number of ball losses) from B1 to B4 as compared with 1T and 2T forms. Moreover, the SSG played in 1T form led to reach higher solicitation of the high-intensity actions while players presented more difficulty to perform a correct technical action.

Conclusions:

The modification of the number of ball touches authorized per possession affects the soccer player activity from the first to the last bout of SSG, indicating that the determination of this rule has to be precisely planned by the coach according to the objectives of the training.
The Use of Session-RPE Method for Quantifying Training Load in Diving
Authors: Minganti Carlo , Capranica Laura , Meeusen Romain , Piacentini Maria Francesca
Published: August 2016

Purpose:

The aim of the present study was to assess the effectiveness of perceived exertion (session-RPE) in quantifying internal training load in divers.

Methods:

Six elite divers, three males (age, 25.7 ± 6.1 y; stature, 1.71 ± 0.06 m; body mass, 66.7 ± 1.2 kg) and three females (age, 25.3 ± 0.6 y; stature, 1.63 ± 0.05 m; body mass, 58.3 ± 4.0 kg) were monitored during six training sessions within a week, which included 1 m and 3 m springboard dives. The Edwards summated heart rate zone method was used as a reference measure; the session-RPE rating was obtained using the CR-10 Borg scale modified by Foster and the 100 mm visual analog scale (VAS).

Results:

Significant correlations were found between CR-10 and VAS session-RPE and the Edwards summated heart rate zone method for training sessions (r range: 0.71–0.96; R2 range: 0.50–0.92; P < 0.01) and for divers (r range: 0.67–0.96; R2 range: 0.44–0.92; P < 0.01).

Conclusions:

These findings suggest that session-RPE can be useful for monitoring internal training load in divers.
Effect of Creatine Supplementation Jumping Performance in Elite Volleyball Players
Authors: Lamontagne-Lacasse Martin , Nadon Raymond , Goulet Eric D.B.
Published: August 2016

Jump height is a critical aspect of volleyball players’ blocking and attacking performance. Although previous studies demonstrated that creatine monohydrate supplementation (CrMS) improves jumping performance, none have yet evaluated its effect among volleyball players with proficient jumping skills. We examined the effect of 4 wk of CrMS on 1 RM spike jump (SJ) and repeated block jump (BJ) performance among 12 elite males of the Sherbrooke University volleyball team. Using a parallel, randomized, double-blind protocol, participants were supplemented with a placebo or creatine solution for 28 d, at a dose of 20 g/d in days 1–4, 10 g/d on days 5-6, and 5 g/d on days 7-28. Pre- and postsupplementation, subjects performed the 1 RM SJ test, followed by the repeated BJ test (10 series of 10 BJs; 3 s interval between jumps; 2 min recovery between series). Due to injuries (N = 2) and outlier data (N = 2), results are reported for eight subjects. Following supplementation, both groups improved SJ and repeated BJ performance. The change in performance during the 1 RM SJ test and over the first two repeated BJ series was unclear between groups. For series 3-6 and 7-10, respectively, CrMS further improved repeated BJ performance by 2.8% (likely beneficial change) and 1.9% (possibly beneficial change), compared with the placebo. Percent repeated BJ decline in performance across the 10 series did not differ between groups pre- and postsupplementation. In conclusion, CrMS likely improved repeated BJ height capability without influencing the magnitude of muscular fatigue in these elite, university-level volleyball players.
Influence of Sodium Bicarbonate on Performance and Hydration in Lightweight Rowing
Authors: Kupcis Peter D. , Slater Gary J. , Pruscino Cathryn L. , Kemp Justin G.
Published: August 2016

Purpose:

The effect of sodium bicarbonate (NaHCO3) ingestion on prerace hydration status and on 2000 m ergometer performance in elite lightweight rowers was examined using a randomized, cross-over, double-blinded design.

Methods:

To simulate body mass (BM) management strategies common to lightweight rowing, oarsmen reduced BM by approx. 4% in the 24 h preceding the trials, and, in the 2 h before performance, undertook nutritional recovery consisting of mean 43.2 kJ/kg, 2.2 g of CHO per kilogram, 31.8 mg of Na+ per kilogram, 24.3 mL of H2O per kilogram, and NaHCO3 (0.3 g of NaHCO3 per kilogram BM) or placebo (PL; 0.15 g of corn flour per kilogram BM) at 70 to 90 min before racing.

Results:

At 25 min before performance, NaHCO3 had increased blood pH (7.48 ± 0.02 vs PL: 7.41 ± 0.03, P = .005) and bicarbonate concentrations (29.1 ± 1.8 vs PL: 23.9 ± 1.6 mmol/L, P < .001), whereas BM, urine specific gravity, and plasma volume changes were similar between trials. Rowing ergometer times were similar between trials (NaHCO3: 397.8 ± 12.6; PL: 398.6 ± 13.8 s, P = .417), whereas posttest bicarbonate (11.6 ± 2.3 vs 9.4 ± 1.8 mmol/L, P = .003) and lactate concentration increases (13.4 ± 1.7 vs 11.9 ± 1.9 mmol/L, P = .001) were greater with NaHCO3.

Conclusion:

Sodium bicarbonate did not further enhance rehydration or performance in lightweight rowers when undertaking recommended post-weigh-in nutritional recovery strategies.
Hydration Status in Adolescent Judo Athletes Before and After Training in the Heat
Authors: Rivera-Brown Anita M. , De Félix-Dávila Roberto A.
Published: August 2016

Adolescent judo athletes who train in tropical climates may be in a persistent state of dehydration because they frequently restrict fluids during daily training sessions to maintain or reduce their body weight and are not given enough opportunities to drink.

Purpose:

Determine the body hydration status of adolescent judo athletes before, immediately after, and 24 h after (24H) a training session and document sweat Na+ loss and symptoms of dehydration.

Methods:

Body mass and urine color and specific gravity (USG) were measured before, after, and 24 h after a training session in a high-heat-stress environment (29.5 ± 1.0°C; 77.7 ± 6.1% RH) in 24 adolescent athletes. Sweat sodium loss was also determined. A comparison was made between mid-pubertal (MP) and late pubertal (LP) subjects.

Results:

The majority of the subjects started training with a significant level of dehydration. During the training session, MP subjects lost 1.3 ± 0.8% of their pretraining body mass whereas LP subjects lost 1.9 ± 0.5% (P < .05). Sweat sodium concentration was 44.5 ± 23.3 mmol/L. Fluid intake from a water fountain was minimal. Subjects reported symptoms of dehydration during the session, which in some cases persisted throughout the night and the next day. The 24H USG was 1.028 ± 0.004 and 1.027 ± 0.005 g/mL for MP and LP, respectively.

Conclusions:

Adolescent judo athletes arrive to practice with a fluid deficit, do not drink enough during training, and experience symptoms of dehydration, which may compromise the quality of training and general well-being.
Complex Interplay Between Determinants of Pacing and Performance During 20-km Cycle Time Trials
Authors: Renfree Andrew , West Julia , Corbett Mark , Rhoden Clare , Gibson Alan St Clair
Published: August 2016

Purpose:

This study examined the determinants of pacing strategy and performance during self-paced maximal exercise.

Methods:

Eight well-trained cyclists completed two 20-km time trials. Power output, rating of perceived exertion (RPE), positive and negative affect, and iEMG activity of the active musculature were recorded every 0.5 km, confidence in achieving preexercise goals was assessed every 5 km, and blood lactate and pH were measured postexercise. Differences in all parameters were assessed between fastest (FAST) and slowest (SLOW) trials performed.

Results:

Mean power output was significantly higher during the initial 90% of FAST, but not the final 10%, and blood lactate concentration was significantly higher and pH significantly lower following FAST. Mean iEMG activity was significantly higher throughout SLOW. Rating of perceived exertion was similar throughout both trials, but participants had significantly more positive affect and less negative affect throughout FAST. Participants grew less confident in their ability to achieve their goals throughout SLOW.

Conclusions:

The results suggest that affect may be the primary psychological regulator of pacing strategy and that higher levels of positivity and lower levels of negativity may have been associated with a more aggressive strategy during FAST. Although the exact mechanisms through which affect acts to influence performance are unclear, it may determine the degree of physiological disruption that can be tolerated, or be reflective of peripheral physiological status in relation to the still to be completed exercise task.
Reverse Lactate Threshold: A Novel Single-Session Approach to Reliable High-Resolution Estimation of the Anaerobic Threshold
Authors: Dotan Raffy
Published: August 2016

The multisession maximal lactate steady-state (MLSS) test is the gold standard for anaerobic threshold (AnT) estimation. However, it is highly impractical, requires high fitness level, and suffers additional shortcomings. Existing single-session AnT-estimating tests are of compromised validity, reliability, and resolution. The presented reverse lactate threshold test (RLT) is a single-session, AnT-estimating test, aimed at avoiding the pitfalls of existing tests. It is based on the novel concept of identifying blood lactate’s maximal appearance-disappearance equilibrium by approaching the AnT from higher, rather than from lower exercise intensities. Rowing, cycling, and running case data (4 recreational and competitive athletes, male and female, aged 17–39 y) are presented. Subjects performed the RLT test and, on a separate session, a single 30-min MLSS-type verification test at the RLT-determined intensity. The RLT and its MLSS verification exhibited exceptional agreement at 0.5% discrepancy or better. The RLT’s training sensitivity was demonstrated by a case of 2.5-mo training regimen following which the RLT’s 15-W improvement was fully MLSS-verified. The RLT’s test-retest reliability was examined in 10 trained and untrained subjects. Test 2 differed from test 1 by only 0.3% with an intraclass correlation of 0.997. The data suggest RLT to accurately and reliably estimate AnT (as represented by MLSS verification) with high resolution and in distinctly different sports and to be sensitive to training adaptations. Compared with MLSS, the single-session RLT is highly practical and its lower fitness requirements make it applicable to athletes and untrained individuals alike. Further research is needed to establish RLT’s validity and accuracy in larger samples.
Strength Gains: Block Versus Daily Undulating Periodization Weight Training Among Track and Field Athletes
Authors: Painter Keith B. , Haff Gregory G. , Ramsey Mike W. , McBride Jeff , Triplett Travis , Sands William A. , Lamont Hugh S. , Stone Margaret E. , Stone Michael H.
Published: August 2016

Recently, the comparison of “periodized” strength training methods has been a focus of both exercise and sport science. Daily undulating periodization (DUP), using daily alterations in repetitions, has been developed and touted as a superior method of training, while block forms of programming for periodization have been questioned. Therefore, the purpose of this study is to compare block to DUP in Division I track and field athletes. Thirty-one athletes were assigned to either a 10-wk block or DUP training group in which sex, year, and event were matched. Over the course of the study, there were 4 testing sessions, which were used to evaluate a variety of strength characteristics. Although performance trends favored the block group for strength and rate of force development, no statistically significant differences were found between the 2 training groups. However, statistically different (P ≤ .05) values were found for estimated volume of work (volume load) and the amount of improvement per volume load between block and DUP groups. Based on calculated training efficiency scores, these data indicate that a block training model is more efficient than a DUP model in producing strength gains.
Warm-Up Intensity and Duration’s Effect on Traditional Rowing Time-Trial Performance
Authors: Mujika Iñigo , de Txabarri Rafa González , Maldonado-Martín Sara , Pyne David B.
Published: August 2016

The warm-up procedure in traditional rowing usually involves continuous low-intensity rowing and short bouts of intense exercise, lasting about 60 min.

Purpose:

To compare the effects of a traditional and an experimental 30-min warm-up of lower intensity on indoor rowing time-trial performance.

Methods:

Fourteen highly trained male rowers (age 25.9 ± 5.3 y, height 1.86 ± 0.06 m, mass 80.4 ± 5.2 kg, peak aerobic power 352.0 ± 24.4 W; mean ± SD) performed 2 indoor rowing trials 12 d apart. Rowers were randomly assigned to either LONG or SHORT warm-ups using a crossover design, each followed by a 10-min all-out fixed-seat rowing-ergometer time trial.

Results:

Mean power output during the time trial was substantially higher after SHORT (322 ± 18 vs 316 ± 17 W), with rowers generating substantially more power in the initial 7.5 min of the time trial after SHORT. LONG elicited substantially higher mean warm-up heart rate than SHORT (134 ± 11 vs 121 ± 13 beats/min), higher pre–time-trial rating of perceived exertion (10.2 ± 1.4 vs 7.6 ± 1.7) and blood lactate (1.7 ± 0.4 mM vs 1.2 ± 0.2 mM), but similar heart rate (100 ± 14 vs 102 ± 9 beats/min). No substantial differences were observed between LONG and SHORT in stroke rate (39.4 ± 2.0 vs 39.4 ± 2.2 strokes/min) or mean heart rate (171 ± 6 vs 171 ± 8 beats/min) during the time trial, nor in blood lactate after it (11.8 ± 2.5 vs 12.1 ± 2.0 mM).

Conclusion:

A warm-up characterized by lower intensity and shorter duration should elicit less physiological strain and promote substantially higher power production in the initial stages of a rowing time trial.
All for One and One for All! Disparity Between Overall Crew’s and Individual Rowers’ Pacing Strategies During Rowing
Authors: Renfree Andrew , Martin Louise , Richards Ashley , Gibson Alan St Clair
Published: August 2016

Purpose:

This study examined individual contributions to overall pacing strategy during 2- and 5-km rowing trials in a coxless-4 boat.

Methods:

A crew of 4 male rowers performed maximal-effort on-water trials over 2 and 5 km, and power output during every individual stroke was measured for each crew member. Mean overall boat and individual rower stroke power were calculated for each 25% epoch (25% of total strokes taken), and power for each individual epoch was calculated as a percentage of mean power maintained over the entire distance. The coefficient of variation was used to determine stroke-to-stroke and epoch-to-epoch variability for individual rowers and the overall boat.

Results:

In both trials, the overall pacing strategy consisted of a high power output in the initial 25% that decreased in the middle 50% and increased again in the final 25%. However, individual rower data indicate wide variation in individual power profiles that did not always mimic the overall boat profile.

Conclusions:

This study demonstrates that overall boat power profiles during 2- and 5-km rowing trials are similar to velocity profiles previously reported for individual ergometry and on-water racing events. However, this overall profile is achieved despite considerable variation in individual rower profiles. Further research is warranted to determine the mechanisms through which individual contributions to overall pacing strategy are regulated and the effectiveness or otherwise of seemingly disparate individual strategies on overall performance.
Changes of Whole-Body Power, Muscle Function, and Jump Performance With Prolonged Cycling to Exhaustion
Authors: McIntyre Jordan P.R. , Mawston Grant A. , Cairns Simeon P.
Published: August 2016

Purpose:

To quantify how whole-body power, muscle-function, and jump-performance measures change during prolonged cycling and recovery and determine whether there are relationships between the different fatigue measures.

Methods:

Ten competitive or recreationally active male cyclists underwent repeated 20-min stages of prolonged cycling at 70% VO2peak until exhaustion. Whole-body peak power output (PPO) was assessed using an all-out 30-s sprint 17 min into each cycle stage. Ratings of perceived exertion (RPE) were recorded throughout. Isometric and isokinetic muscle-function tests were made between cycle stages, over ~6 min, and during 30-min recovery. Drop-jump measures were tested at exhaustion and during recovery.

Results:

PPO initially increased or was maintained in some subjects but fell to 81% of maximum at exhaustion. RPE was near maximal (18.7) at exhaustion, with the time to exhaustion related to the rate of rise of RPE. PPO first started to decline only when RPE exceeded 16 (ie, hard). Peak isometric and concentric isokinetic torque (180°/s) for the quadriceps fell to 86% and 83% of pretest at exhaustion, respectively. In contrast, the peak concentric isokinetic torque (180°/s) of the hamstrings increased by 10% before declining to 93% of maximum. Jump height fell to 92% of pretest at exhaustion and was correlated with the decline in PPO (r = .79). Muscle-function and jump-performance measures did not recover over the 30-min postexercise rest period.

Conclusions:

At exhaustion, whole-body power, muscle-function, and jump-performance measures had all fallen by 7–19%. PPO and drop-jump decrements were linearly correlated and are appropriate measures of maximal performance.