bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Quercetin Supplementation on Endurance Performance and Maximal Oxygen Consumption: A Meta-Analysis
Authors: Pelletier Denis M. , Lacerte Guillaume , Goulet Eric D.B.
Published: August 2016

Lately, the effect of quercetin supplementation (QS) on endurance performance (EP) and maximal oxygen consumption (VO2max) has been receiving much scientific and media attention. Therefore, a meta-analysis was performed to determine QS’s ergogenic value on these variables. Studies were located with database searches (PubMed and SPORTDiscus) and cross-referencing. Outcomes represent mean percentage changes in EP (measured via power output) and VO2max between QS and placebo. Random-effects model meta-regression, mixed-effects model analog to the ANOVA, random-effects weighted mean effect summary, and magnitudebased inferences analyses were used to delineate the effects of QS. Seven research articles (representing 288 subjects) were included, producing 4 VO2max and 10 EP effect estimates. Mean QS daily intake and duration were, respectively, 960 ± 127 mg and 26 ± 24 d for the EP outcome and 1,000 ± 0 mg and 8 ± 23 d for the VO2max outcome. EP was assessed during exercise with a mean duration of 79 ± 82 min. Overall, QS improved EP by 0.74% (95% CI: 0.10–1.39, p = .02) compared with placebo. However, only in untrained individuals (0.83% ± 0.78%, p = .02) did QS significantly improve EP (trained individuals: 0.09% ± 2.15%, p = .92). There was no relationship between QS duration and EP (p = .69). Overall, QS increased VO2max by 1.94% (95% CI: 0.30–3.59, p = .02). Magnitude-based inferences suggest that the effect of QS on EP and VO2max is likely to be trivial for both trained and untrained individuals. In conclusion, this meta-analysis indicates that QS is unlikely to prove ergogenic for aerobic-oriented exercises in trained and untrained individuals.
The Effect of Ice Slushy Ingestion and Mouthwash on Thermoregulation and Endurance Performance in the Heat
Authors: Burdon Catriona A. , Hoon Matthew W. , Johnson Nathan A. , Chapman Phillip G. , O’Connor Helen T.
Published: August 2016

Purpose:

The purpose of this study was to establish whether sensory factors associated with cold-beverage ingestion exert an ergogenic effect on endurance performance independent of thermoregulatory or cardiovascular factors.

Methods:

Ten males performed three trials involving 90 min of steady state cycling (SS; 62% VO2max) in the heat (32.1 ± 0.9 °C, 40 ± 2.4% relative humidity) followed by a 4 kJ/kg body mass time trial (TT). During SS, participants consumed an identical volume (260 ± 38g) of sports beverage (7.4% carbohydrate) every 15 min as either ice slushy (–1 °C; ICE), thermoneutral liquid (37 °C; CON), or thermoneutral liquid consumption with expectorated ice slushy mouthwash (WASH).

Results:

Rectal temperature, hydration status, heart rate, and skin blood flow were not different between trials. Gastrointestinal (pill) temperature was lower in ICE (35.6 ± 2.7 °C) versus CON (37.4 ± 0.7 °C, p = .05). Heat storage tended to be lower with ICE during SS (14.7 ± 8.4W.m−2, p = .08) and higher during TT (68.9 ± 38.6W.m−2, p = .03) compared with CON (22.1 ± 6.6 and 31.4 ± 27.6W.m−2). ICE tended to lower the rating of perceived exertion (RPE, 12.9 ± 0.6, p = .05) and improve thermal comfort (TC, 4.5 ± 0.2; p = .01) vs. CON (13.8 ± 1.0 and 5.2 ± 0.2 respectively). WASH RPE (13.0 ± 0.8) and TC (4.8 ± 0.2) tended to be lower versus CON (p = .07 and p = .09 respectively). ICE improved performance (18:28 ± 1:03) compared with CON (20:24 ± 1:46) but not WASH (19:45 ± 1:43).

Conclusion:

Improved performance with ICE ingestion likely resulted from the creation of a gastrointestinal heat sink, reducing SS heat storage. Although the benefits of cold-beverage consumption are more potent when there is ingestion, improved RPE, TC, and meaningful performance improvement with WASH supports an independent sensory effect of presenting a cold stimulus to the mouth.
The Effect of Nitrate Supplementation on Exercise Performance in Healthy Individuals: A Systematic Review and Meta-Analysis
Authors: Hoon Matthew W. , Johnson Nathan A. , Chapman Phillip G. , Burke Louise M.
Published: August 2016

The purpose of this review was to examine the effect of nitrate supplementation on exercise performance by systematic review and meta-analysis of controlled human studies. A search of four electronic databases and cross-referencing found 17 studies investigating the effect of inorganic nitrate supplementation on exercise performance that met the inclusion criteria. Beetroot juice and sodium nitrate were the most common supplements, with doses ranging from 300 to 600 mg nitrate and prescribed in a manner ranging from a single bolus to 15 days of regular ingestion. Pooled analysis showed a significant moderate benefit (ES = 0.79, 95% CI: 0.23–1.35) of nitrate supplementation on performance for time to exhaustion tests (p = .006). There was a small but insignificant beneficial effect on performance for time trials (ES = 0.11, 95% CI: –0.16–0.37) and graded exercise tests (ES = 0.26, 95% CI: –0.10–0.62). Qualitative analysis suggested that performance benefits are more often observed in inactive to recreationally active individuals and when a chronic loading of nitrate over several days is undertaken. Overall, these results suggest that nitrate supplementation is associated with a moderate improvement in constant load time to exhaustion tasks. Despite not reaching statistical significance, the small positive effect on time trial or graded exercise performance may be meaningful in an elite sport context. More data are required to clarify the effect of nitrate supplementation on exercise performance and to elucidate the optimal way to implement supplementation.
The Yo-Yo Test: Reliability and Association with a 20-m Shuttle Run and VO2max
Authors: Thomas Andrew , Dawson Brian , Goodman Carmel
Published: August 2016

Purpose:

The purpose of the study was to determine the reliability of yo-yo intermittent recovery test (yo-yo) scores and their degree of association with a 20-m shuttle run (20MSR) and VO2max values.

Methods:

Subjects were elite (Australian Football League [AFL], n = 23), state-level (hockey, n = 15, and cricket, n = 27), and recreational team-sport players (n = 33). All performed a 20MSR and the yo-yo at either level 1 (recreational and state level) or level 2 (AFL). A recreational subgroup (n = 19) also performed a treadmill VO2max test.

Results:

Test–retest results found the yo-yo (levels 1 and 2) to be reliable (ICC = .86 to .95). The 20MSR and yo-yo level 1 scores correlated (P < .01) in the recreational (r = .81 to .83) and state-level groups (r = .84 to .86), and 20MSR and yo-yo level 2 scores, in the elite (r = .86) and recreational groups (r = .55 to .57). The VO2max and yo-yo level 1 scores in the recreational group correlated (P < .01, r = .87), but no association was found with yo-yo level 2 (r = .40 to .43, non significant).

Conclusions:

We conclude that level 1 (recreational and state level) and level 2 (elite) yo-yo scores were both strongly associated with 20MSR scores and VO2max (level 1: recreational subjects only). The yo-yo appears to measure aerobic fitness similarly to the 20MSR but may also be used as a field test of the ability to repeat high-intensity efforts.
Physical Fitness Components Associated With Performance in a Multiple-Sprint Test
Authors: Durandt Justin , Tee Jason C. , Prim Sebastian K. , Lambert Michael I.
Published: August 2016

Purpose:

The 5-m repeat-sprint test (5-m RST) measures resistance to fatigue after repeated bouts of short-duration, high-intensity activity. This study determined the components of fitness associated with performance in 5-m RSTs.

Methods:

Speed (10-m and 40-m sprints), strength (bench press), agility, strength endurance (pull-ups and push-ups), and aerobic power (20-m shuttle-run test) were measured in male provincial- or national-level rugby (n = 110), hockey (n = 59), and soccer (n = 55) players.

Results:

Subjects with either high (HI) or low (LO) resistance to fatigue in the 5-m RST differed in body mass (76.9 ± 11.6 kg vs 102.1 ± 18.9 kg, HI vs LO, respectively, P < .001), agility (14.55 ± 0.41 seconds vs 15.56 ± 0.30 seconds, P < .001), bench press (86 ± 20 kg vs 114 ± 33 kg, P = .03), pull-ups (13 ± 4 vs 8 ± 5, P = .02), push-ups (56 ± 12 vs 39 ± 13, P = .002), and 20-m shuttle-run test (20-m SRT; 133 ± 11 vs 87 ± 12 shuttles, P < .001). Body mass, strength, and aerobic power were the best predictors of 5-m RST performance: 5-m RST = –1.274(mass) + 0.756(1RM bench press) + 2.053(number of 20-m SRT shuttles) + 549.409 (R2 = .66).

Conclusions:

Performance in the 5-m RST is predicted best by a combination of factors including body mass, strength, and aerobic ability, rather than by any single component of fitness.
Water Immersion: Does It Enhance Recovery From Exercise?
Authors: Wilcock Ian M. , Cronin John B. , Hing Wayne A.
Published: August 2016

Purpose:

To assess the effect that post exercise immersion in water has on subsequent exercise performance.

Methods:

A literary search and review of water-immersion and performance studies was conducted.

Results:

Seven articles were examined. In 2, significant benefits to performance were observed. Those 2 articles revealed a small to large effect on jump performance and isometric strength.

Practical Application and Conclusions:

It is possible that water immersion might improve recovery from plyometric or muscle-damaging exercise. Such a statement needs to be verified, however, because of the scarcity of research on water immersion as a recovery strategy.
Side Effects of Creatine Supplementation in Athletes
Authors: Francaux Marc , Poortmans Jacques R.
Published: August 2016

Context:

Allegations about side effects of creatine supplementation by athletes have been published in the popular media and scientific publications.

Purpose:

To examine the experimental evidence relating to the physiological effects of creatine supplementation.

Results:

One of the purported effects of oral creatine supplementation is increased muscle mass. A review of the literature reveals a 1.0% to 2.3% increase in body mass, which is attributed to fat-free mass and, more specifically, to skeletal-muscle mass. Although it is unlikely that water retention can completely explain these changes, increase in muscle-protein synthesis has never been observed after creatine supplementation. Indirect evidence based on mRNA analyses suggests that transcription of certain genes is enhanced. Although the effect of creatine on muscle-protein synthesis seems irrefutable according to advertising, this allegation remains under debate in the scientific literature. The kidneys appear to maintain their functionality in healthy subjects who supplement with creatine, even over several months.

Conclusion:

The authors, however, think that creatine supplementation should not be used by an individual with preexisting renal disease and that risk should be evaluated before and during any supplementation period. Even if there is a slight increase in mutagenic agents (methylamine and formaldehyde) in urine after a heavy load of creatine (20 g/day), their excretion remains within a normal range. No data are currently available regarding the potential production of heterocyclic amines with creatine supplementation. In summary, the major risk for health is probably associated with the purity of commercially available creatine.
Power Output During a Professional Men’s Road-Cycling Tour
Authors: Ebert Tammie R. , Martin David T. , Stephens Brian , Withers Robert T.
Published: August 2016

Purpose:

To quantify the power-output demands of men’s road-cycling stage racing using a direct measure of power output.

Methods:

Power-output data were collected from 207 races over 6 competition years on 31 Australian national male road cyclists. Subjects performed a maximal graded exercise test in the laboratory to determine maximum aerobic-power output, and bicycles were fitted with SRM power meters. Races were described as fl at, hilly, or criterium, and linear mixed modeling was used to compare the races.

Results:

Criterium was the shortest race and displayed the highest mean power output (criterium 262 ± 30 v hilly 203 ± 32 v fl at 188 ± 30 W), percentage total race time above 7.5 W/kg (crite-rium 15.5% ± 4.1% v hilly 3.8% ± 1.7% v fl at 3.5% ± 1.4%) and SD in power output (criterium 250 v hilly 165 v fl at 169 W). Approximately 67%, 80%, and 85% of total race time was spent below 5 W/kg for criterium, hilly and fl at races, respectively. About 70, 40, and 20 sprints above maximum aerobic-power output occurred during criterium, hilly, and fl at races, respectively, with most sprints being 6 to 10 s.

Conclusions:

These data extend previous research documenting the demands of men’s road cycling. Despite the relatively low mean power output, races were characterized by multiple high-intensity surges above maximum aerobic-power output. These data can be used to develop sport-specific interval-training programs that replicate the demands of competition.
Monitoring Different Types of Resistance Training Using Session Rating of Perceived Exertion
Authors: Singh Favil , Foster Carl , Tod David , McGuigan Michael R.
Published: August 2016

Purpose:

To evaluate the effectiveness of session rating of perceived exertion (RPE) to measure effort during different types of resistance training.

Method:

Fifteen male subjects (age 26.7 ± 4.3 years) performed 3 protocols. All protocols consisted of same 5 exercises but with different intensities, rest periods, and numbers of repetitions. One-repetition maximum (1-RM) was defined as the maximal amount of weight that an individual could lift 1 time without support. The strength protocol included 3 sets of 5 repetitions at 90% of 1-RM with 3 minutes rest between. The hypertrophy session included 3 sets of 10 repetitions at 70% with 1 minute of rest, and the power session included 3 sets of 5 repetitions at 50% with 3 minutes of rest. Session RPE is a modification of the standard RPE scale. Session and standard RPE were measured after the completion of each set and 30 minutes postexercise, respectively.

Results:

Results showed a difference between both the 2 RPE values of the strength and hypertrophy protocols (P ≤ .05) but no difference between mean and session RPE values for the power protocol. During the familiarization session, session RPE was measured at 5-minute intervals for 30 minutes postexercise. There was a significant difference (P ≤ .05) between the mean RPE values at the fifth and tenth minutes postexercise when compared with 30 minutes postexercise. All other session RPE values showed no significant difference.

Conclusion:

The session RPE method appears to be effective in monitoring different types of resistance training, and session RPE after 30 minutes was a better indicator of the overall resistance sessions than average RPE.
Bilateral Comparison of Barbell Kinetics and Kinematics During a Weightlifting Competition
Authors: Rossi Stephen J. , Buford Thomas W. , Smith Douglas B. , Kennel Robin , Haff Erin E. , Haff G. Gregory
Published: August 2016

Purpose:

The primary purpose of this study was to simultaneously analyze both ends of the barbell with 19 weightlifters (age 18.0 ± 3.2 years, body mass 84.0 ± 14.2 kg, height 167.3 ± 8.7 cm) participating in a weightlifting competition to determine whether there were asymmetries in barbell kinematics and kinetics between the right and left sides of the barbell. The second purpose was to compare barbell-trajectory classification of the snatch and clean lifts between the right and left sides of the barbell.

Methods:

Barbell kinematic and kinetic data were collected and analyzed with 2 VS-120 weightlifting-analysis systems (Lipman Electronic Engineering Ltd, Ramat Hahayal, Israel). Barbell trajectories (A, B, and C) for the right and left sides were analyzed for each lift.

Results:

No significant difference was found in trajectory classification between sides of the barbell for either lift. The frequencies analysis revealed that type C barbell trajectories were the most prevalent in each lift. When the right and left sides of the barbell were compared during the snatch and clean, no significant differences were determined for any kinematic or kinetic variables.

Conclusions:

The V-scope system appears to facilitate analysis of barbell kinematics, kinetics, and trajectories during weightlifting competition regardless of which side of the barbell is analyzed.
Highland Dance: Heart-Rate and Blood Lactate Differences Between Competition and Class
Authors: Baillie Yvonne , Wyon Matt , Head Andrew
Published: August 2016

Purpose:

This study looked at the physiological effects of performance in Highland-dance competition to consider whether the traditional methods used during class and rehearsal provide an appropriate training stimulus toward this performance.

Methods:

Nine championship standard, female Highland dancers (age 14.2 ± 1.47 years) had their heart rate and blood lactate concentrations measured before and after 3 dances during a championship competition. Heart rate was also measured during the same 3 dances in rehearsal and during class.

Results:

Repeated-measures analysis of variance showed significant differences in pre dance lactate concentrations between the first dance (Highland Fling, 1.4 ± 0.3 mM/L), the second dance (Sword dance, 2.3 ± 0.8 mM/L), and the third dance (Sean Truibhas, 3.5 ± 1.8 mM/L;F2,16= 11.72,P< .01. This, coupled with a significant rise in lactate concentration during the dances (F1,8= 76.75,P< .001), resulted in a final post dance lactate concentration of 7.3 ± 2.96 mM/L. Heart-rate data during competition, rehearsal, and class (195.0 ± 6.5, 172.6 ± 5.4, and 151.9 ± 7.4 beats/min, respectively) showed significant differences between all 3 (F2,16= 107.1,P< .001); these are comparable to research on other dance forms.

Conclusions:

Given the disparity between the anaerobic predominance of competition and the aerobic predominance during class, it is suggested that the class does not provide an appropriate training stimulus as preparation for competitive performance in Highland dance.
Effect of Instability and Resistance on Unintentional Squat-Lifting Kinetics
Authors: Drinkwater Eric J. , Pritchett Erica J. , Behm David G.
Published: August 2016

Context:

Resistance training while using an instability-training device is known to increase activation of stabilizing muscle groups while decreasing the force generated by the prime movers during isometric contractions.

Purpose:

To investigate differences in squat kinetics during dynamic resistance training in an increasingly unstable training environment.

Methods:

Fourteen active men participated in this study. In each testing session, each participant performed 3 repetitions of squats with a 10-repetition maximum (10-RM) resistance, 40% of their 10-RM resistance, and 20.45 kg. The 3 testing session consisted of standing on a stable foor, foam pads, or BOSU balls. All repetitions were recorded with an optical encoder to record barbell kinetics.

Results:

The transition from stable (floor) to very unstable (BOSU) resulted in high likelihoods (>75%) of clinically meaningful differences ranging from small to large (effect size [ES] 0.31–1.73) in factors relating to concentric kinetics, eccentric power, and squat depth, regardless of the resistance used for training. There were also likely differences at the heaviest resistance in peak concentric power (stable to foam: ES 2.06; foam to BOSU: ES 0.38), eccentric power (stable to foam: ES 1.88; foam to BOSU: ES 0.74), and squat depth (stable to foam: ES 0.50; foam to BOSU: ES 0.67).

Conclusions:

Resistance training in an unstable environment at an intensity sufficient to elicit strength gains of the prime movers results in deleterious effects in concentric squat kinetics and squat technique. Such observations are particularly evident on very unstable platforms.
Relationship Between Throwing Velocity, Muscle Power, and Bar Velocity During Bench Press in Elite Handball Players
Authors: Marques Mário C. , van den Tillaar Roland , Vescovi Jason D. , González-Badillo Juan José
Published: August 2016

Purpose:

The purpose of this study was to examine the relationship between ball-throwing velocity during a 3-step running throw and dynamic strength, power, and bar velocity during a concentric-only bench-press exercise in team-handball players.

Methods:

Fourteen elite senior male team-handball players volunteered to participate. Each volunteer had power and bar velocity measured during a concentric-only bench-press test with 26, 36, and 46 kg, as well as having 1-repetition-maximum (1-RMBP) strength determined. Ball-throwing velocity was evaluated with a standard 3-step running throw using a radar gun.

Results:

Ball-throwing velocity was related to the absolute load lifted during the 1-RMBP (r = .637, P = .014), peak power using 36 kg (r = .586, P = .028) and 46 kg (r = .582, P = .029), and peak bar velocity using 26 kg (r = .563, P = .036) and 36 kg (r = .625, P = .017).

Conclusions:

The results indicate that throwing velocity of elite team-handball players is related to maximal dynamic strength, peak power, and peak bar velocity. Thus, a training regimen designed to improve ball-throwing velocity in elite male team-handball players should include exercises that are aimed at increasing both strength and power in the upper body.
The Application of Postactivation Potentiation to Elite Sport
Authors: Docherty David , Hodgson Matthew J.
Published: August 2016

Recently there has been considerable interest and research into the functional significance of postactivation potentiation (PAP) on sport performance. The interest has evolved around the potential for enhancing acute performance or the long-term training effect, typically in the form of complex training. Complex training usually involves performing a weight-training exercise with high loads before executing a plyometric exercise with similar biomechanical demands. Despite a considerable amount of research in the past 10 years it would seem there is still much research to be done to fully determine whether PAP has a functional role and, if so, how to best exploit it. It is clear from the research that there are many factors that need to be considered when attempting to apply PAP to an athlete. It is possible that a well-conceived sport-specific warm-up might be as or more effective in enhancing acute performance and easier to apply in a practical setting. In addition, despite its current popularity, there has not been 1 study that has effectively examined the efficacy of complex training and whether it has any advantage over other forms of training that combine weight training and plyometrics but not in the same training session.
A Time–Motion Analysis of Elite Solo Synchronized Swimming
Authors: Alentejano Teresa , Marshall Dru , Bell Gordon
Published: August 2016

Purpose:

To determine the total amount and relative time periods of face immersion (FI) in a synchronized swimming solo routine and the relationship between FI, distance covered, and the technical-merit score of the 11 top Canadian soloists at a synchronized swimming national championship (mean age 20 ± 1.8 y, height 173.3 ± 4.1 cm, and body mass 58.3 ± 4 kg).

Methods:

Videotape and timing of solo performances combined with manual tracking of pool patterns.

Results:

Analysis of performance revealed that an average of 18 FI periods, mean of 6.8 s, were performed for an average total time of 133.7 ± 27.1 s (range 102.2 to 199.8 s). The average longest FI time period was 25.45 ± 6.2 s (range 18.18 to 38.72 s), and most (10/11) of these were in the first third of the solo. The mean total horizontal distance covered was 57.61 ± 6.84 m (range 48.61 to 68.2 m), and the total horizontal distance covered relative to time was 0.276 ± 0.034 m/s (range 0.235 to 0.340 m/s). No significant relationships were found between any of the FI periods and the distance covered or between the technical-merit score and FI periods. Each solo contained 6 to 8 underwater sequences, none of which were longer than 40 seconds, the cutoff deemed dangerous by FINA (Fédération Internationale de Natation).

Conclusion:

This study shows that the times underwater for solos in Canada are within safety limits recommended by FINA and that judging in Canada is not related to underwater periods of swimming.
An Investigation of the Type and Frequency of Movement Patterns of National Hockey League Goaltenders
Authors: Bell Gordon J. , Snydmiller Gary D. , Game Alex B.
Published: August 2016

Twenty-four National Hockey League (NHL) goaltenders were observed to determine the types and frequency of their movements during actual games. A secondary purpose was to compare these movements across the 3 periods of game play and between 2 NHL seasons (2003–04 and 2005–06) as a result of several rule changes between seasons. The mean (± SD) age, height, body mass, and years of NHL experience of the goaltenders were 30 ± 4 y, 85.4 ± 4.4 kg, 184.0 ± 3.8 cm, 6.6 ± 4.0 y, respectively. The mean (± SD) number of times and type of movements used during a game in order of most frequent were vertical movement (43.7 ± 10.3), moving laterally (39.7 ± 12.7), moving into full-butterfly position (32.1), anterior–posterior movement in front of goal crease (31.5 ± 11.5), skating out of the goal area to play the puck (19.7 ± 6.3), and using a half butterfly on a single leg pad (left = 5.2 ± 1.9, right = 6.4 ± 2.1). Goaltenders played the puck less frequently during the final period of the game than during the first 2 periods and more frequently between the 2 different NHL seasons after certain rule changes. It was concluded that NHL goaltenders move most frequently vertically, laterally, and out of the net to play the puck. In addition, goaltenders moved out of the goal area to play the puck less often in the third period but more frequently after several league rule changes designed to reduce this movement.
Seasonal Changes of Body Mass, Body Composition, and Muscular Performance in Collegiate Wrestlers
Authors: Buford Thomas W. , Smith Douglas B. , O’Brien Matthew S. , Warren Aric J. , Rossi Stephen J.
Published: August 2016

Purpose:

The purpose of the present investigation was to examine the physiological response of collegiate wrestlers to their competitive season.

Methods:

Eleven Division I collegiate wrestlers (mean ± SD; 19.45 ± 1.13 y) volunteered and completed 4 testing sessions throughout the course of the collegiate wrestling season. Testing sessions were conducted pre-, mid-, and postseason, as well as before the national tournament. Testing consisted of weigh-in, skinfold body composition testing, and a 50-rep concentric, isokinetic leg extension muscle endurance test (180°/s). Muscular performance variables measured included peak torque, peak torque at fatigue, percent decline, and peak torque/body mass ratio.

Results:

A significant increase (P < .05) of 2.9% was observed for body mass between midseason and postseason (2.38 kg). From pre- to postseason, a mean increase of 3.8% (3.1 kg) was observed for body mass. An increase (P < .05) in BF% of 2.9% was observed between prenationals and postseason. No significant differences (P > .05) were observed between consecutive time points for quadriceps peak torque; however, there was a significant increase (P < .05) between preseason and prenationals (23.39 N·m). Peak torque at fatigue was greater (P < .05) at midseason than preseason, representing an increase of 9.82 N·m. Between midseason and prenationals testing, we observed an 11% increase (P < .05) in %DCLN. Finally, we noted an increase (P < .05) from 0.6 to 0.69 in peak torque/body mass ratio between preseason and prenationals.

Conclusions:

Our results indicate that while force values seem to suffer at midseason, the wrestlers compensated and were strongest just before their national competition.
The Use of Sprint Tests for Assessment of Speed Qualities of Elite Australian Rules Footballers
Authors: Young Warren , Russell Andrew , Burge Peter , Clarke Alex , Cormack Stuart , Stewart Glenn
Published: August 2016

Purpose:

The purpose of this study was to determine the relationships between split times within sprint tests over 30 m and 40 m in elite Australian Rules footballers.

Methods:

Data were analyzed from two Australian Football League (AFL) clubs. The first club (n = 35) conducted a 40-m sprint test and recorded split times at 10 m and 20 m. The second club (n = 30) conducted a 30-m sprint test and recorded splits at 10 m and 20 m. Analyses included calculation of Pearson correlations and common variances between all the split times as well as “flying” times (20–40 m for the first club and 20 to 30 m for the second club).

Results:

There was a high correlation (r = 0.94) between 10-m time and 20-m time within each club, indicating these measures assessed very similar speed qualities. The correlations between 10-m time and times to 30 m and 40 m decreased, but still produced common variances of 79% and 66% respectively. However when the “flying” times (20–40 m and 20–30 m) were correlated to 10-m time, the common variances decreased substantially to 25% and 42% respectively, indicating uniqueness.

Conclusions:

It was concluded that 10-m time is a good refection of acceleration capabilities and either 20 to 40 m in a 40-m sprint test or 20 to 30 m in a 30-m sprint test can be used to estimate maximum speed capabilities. It was suggested that sprint tests over 30 m or 40 m can be conducted indoors to provide useful information about independent speed qualities in athletes.
Vibration Training in Elite Sport: Effective Training Solution or Just Another Fad?
Authors: Cardinale Marco , Erskine Julie A.
Published: August 2016

The use of vibration as a training intervention has been suggested for more than a decade. Following the initial promising studies, a large number of investigations have been conducted to understand the acute and chronic effects of this novel training modality mainly using special populations, sedentary, physically active, and aged individuals. There is a small number of studies involving athletes. For this reason it is at the moment very difficult to provide safe and effective training guidelines to athletes. We discuss the current findings related to the effectiveness on elite athletes and provide some guidance on practical applications. Vibration is without a doubt an interesting intervention; however, more needs to be done to understand the physiological mechanisms involved in the adaptive responses to vibration exercise. Furthermore, more studies are needed to establish a dose-response relationship to vibration training to provide indications on safe and effective vibration training prescriptions.
Effect of Blood Lactate Sample Site and Test Protocol on Training Zone Prescription in Rowing
Authors: Garland Stephen W. , Atkinson Greg
Published: August 2016

Purpose:

To assess the effect of sample site (earlobe vs toe) and incremental exercise protocol (continuous vs discontinuous) on training zone prescription in rowing.

Methods:

Twenty-six rowers performed two incremental exercise tests on an ergometer: (1) a five-step discontinuous test with 4-min stages and 30-W increment, with blood samples taken from the earlobe and toe at the start of the 1-min break between steps; (2) a continuous test, with 2-min stages and 30-W increment, with blood samples taken from the right first toe at the end of each stage. Blood was analyzed for lactate concentration.

Results:

At a lactate concentration of 2 mmol·L−1, the mean (95% CI) power output was 8.1 (± 15.4) W greater for the continuous protocol, the random error between the methods (1.96 × SD of differences) was ± 58.8 W, and there was no evidence of any relationship between power output and error between methods. At a lactate concentration of 4 mmol·L−1, the mean (95% CI) power output was 24.2 (± 17.0) W greater for the continuous protocol, and the random error was ± 64.8 W. At 4 mmol·L−1, systematic bias between methods increased with high power outputs.

Conclusions:

The continuous protocol with toe sampling led to higher power outputs for a given lactate concentration compared with the discontinuous protocol with earlobe sampling. This was partly due to the choice of sample site and largely due to the choice of protocol. This bias, and also random variability, makes direct comparison of these tests inappropriate.
The Effects of Compression Garments on Intermittent Exercise Performance and Recovery on Consecutive Days
Authors: Duffield Rob , Edge Johann , Merrells Robert , Hawke Emma , Barnes Matt , Simcock David , Gill Nicholas
Published: August 2016

Purpose:

The aim of this study was to determine whether compression garments improve intermittent-sprint performance and aid performance or self-reported recovery from high-intensity efforts on consecutive days.

Methods:

Following familiarization, 14 male rugby players performed two randomized testing conditions (with or without garments) involving consecutive days of a simulated team sport exercise protocol, separated by 24 h of recovery within each condition and 2 weeks between conditions. Each day involved an 80-min high-intensity exercise circuit, with exercise performance determined by repeated 20-m sprints and peak power on a cart dynamometer (single-man scrum machine). Measures of nude mass, heart rate, skin and tympanic temperature, and blood lactate (La−) were recorded throughout each day; also, creatine kinase (CK) and muscle soreness were recorded each day and 48 h following exercise.

Results:

No differences (P = .20 to 0.40) were present between conditions on either day of the exercise protocol for repeated 20-m sprint efforts or peak power on a cart dynamometer. Heart rate, tympanic temperature, and body mass did not significantly differ between conditions; however, skin temperature was higher under the compression garments. Although no differences (P = .50) in La− or CK were present, participants felt reduced levels of perceived muscle soreness in the ensuing 48 h postexercise when wearing the garments (2.5 ± 1.7 vs 3.5 ± 2.1 for garment and control; P = .01).

Conclusions:

The use of compression garments did not improve or hamper simulated team-sport activity on consecutive days. Despite benefits of reduced self-reported muscle soreness when wearing garments during and following exercise each day, no improvements in performance or recovery were apparent.
Effect of Vibration on Forward Split Flexibility and Pain Perception in Young Male Gymnasts
Authors: Sands William A. , McNeal Jeni R. , Stone Michael H. , Haff G. Gregory , Kinser Ann M.
Published: August 2016

Serious stretching in many sports involves discomfort and is often an early ceiling on improvements.

Purpose:

To continue investigation of the use of vibration to enhance acute range of motion while assessing the influence of vibration and stretching on pressure-to-pain threshold perception.

Methods:

Ten young male gymnasts were assessed for split range of motion. One side split was randomly assigned as the experimental condition, and the other side split was assigned as the control. Both side splits were performed on a vibration device; the experimental condition had the device turned on and the control condition was performed with the device turned off. In addition, the athletes were assessed for pressure-to-pain transition using an algometer on the biceps femoris (stretched muscle) and vastus lateralis (nonstretched muscle) bilaterally.

Results:

Pre-post difference scores between the vibrated split (most improved) and the nonvibrated split were statistically different (P = .001, 95% confidence interval of the difference 2.3 to 5.8 cm). Following the stretching protocol, the force values for the pressure-to-pain threshold comparing the vibrated and nonvibrated biceps femoris muscle were not statistically different. The nonstretched vastus lateralis muscle also showed no statistical difference in pressure-to-pain threshold between the vibration and nonvibration conditions.

Conclusion:

This study showed that vibration improved split range of motion over stretching alone, but did not show a difference in pressure-to-pain perception in either the stretched or nonstretched muscles.
Hypervolemia and Blood Alkalinity: Effect on Physiological Strain in a Warm Environment
Authors: Nelson Michael D. , Stuart-Hill Lynneth A. , Sleivert Gordon G.
Published: August 2016

Purpose:

To evaluate the influence of acute hypervolemia, achieved through the ingestion of a sodium citrate-rich beverage, on cardiovascular strain and thermoregulatory function, during moderate-intensity aerobic exercise in a warm environment. Sodium citrate’s ability to increase buffering capacity was also assessed.

Methods:

Twelve endurance-trained athletes completed two blind randomized treatment trials, separated by a minimum of seven days, on a cycle ergometer under heat stress (30.9°C, 64% RH). The subjects ingested 12 mL·kg−1of (1) Gatorade, the control (CNT), or (2) sodium-citrate plus Gatorade (NaCIT: 170 mmol Na+L−1) before cycling at 15% below ventilatory threshold (VT) for 62 minutes. Core and skin temperature, expired gas samples, heart rate, and perceived exertion were measured throughout exercise. Blood samples were taken before drinking each beverage, before commencing exercise, and throughout the exercise bout.

Results:

Plasma volume (PV) was significantly expanded in the NaCIT trial (3.6 ± 5.5%) and remained significantly higher throughout exercise in the NaCIT trial compared with the CNT trial (P≤ .05). No significant differences were found in heart rate, in core and skin temperature, or in the metabolic data between the treatment groups. NaCIT significantly increased [HCO3−], base excess, and pH throughout the trial.

Conclusion:

Acute oral ingestion of high-sodium citrate beverages before moderate exercise induces mild levels of hypervolemia and improves blood-buffering capacity in humans; however, mild hypervolemia during 62 minutes of moderate exercise does not reduce physiological strain or improve thermoregulation.
Hamstring Activation During Lower Body Resistance Training Exercises
Authors: Ebben William P.
Published: August 2016

Purpose:

The purpose of this study was to evaluate differences in hamstring activation during lower body resistance training exercises. This study also sought to assess differences in hamstring-to-quadriceps muscle activation ratios and gender differences therein.

Methods:

A randomized repeated measures design was used to compare six resistance training exercises that are commonly believed to train the hamstrings, including the squat, seated leg curl, stiff leg dead lift, single leg stiff leg dead lift, good morning, and Russian curl. Subjects included 34 college athletes. Outcome measures included the biceps femoris (H) and rectus femoris (Q) electromyography (EMG) and the H-to-Q EMG ratio, for each exercise.

Results:

Main effects were found for the H (P < 0.001) and Q (P < 0.001). Post hoc analysis identified the specific differences between exercises. In addition, main effects were found for the H-to-Q ratio when analyzed for all subjects (P < 0.001). Further analysis revealed that women achieved between 53.9 to 89.5% of the H-to-Q activation ratios of men, for the exercises assessed. In a separate analysis of strength matched women and men, women achieved between 35.9 to 76.0% of the H-to-Q ratios of men, for these exercises.

Conclusions:

Hamstring resistance training exercises offer differing degrees of H and Q activation and ratios. Women compared with men, are less able to activate the hamstrings and/or more able to activate the quadriceps. Women may require disproportionately greater training for the hamstrings compared with the quadriceps.
Combined Uphill and Downhill Sprint Running Training Is More Efficacious Than Horizontal
Authors: Paradisis Giorgos P. , Bissas Athanassios , Cooke Carlton B.
Published: August 2016

Purpose:

This study examined the effects of sprint running training on sloping surfaces (3°) on selected kinematic and physiological variables.

Methods:

Fifty-four sport and physical education students were randomly allocated to one of two training groups (combined uphill–downhill [U+D] and horizontal (H)) and a control group (C). Pre- and post training tests were performed to examine the effects of 8 wk of training on the maximum running speed (MRS), step rate, step length, step time, contact time, eccentric and concentric phase of contact time (EP, CP), fight time, selected posture characteristics of the step cycle, and 6-s maximal cycle sprint test.

Results:

MRS, step rate, contact time, and step time were improved significantly in a 35-m sprint test for the U+D group (P < .01) after training by 4.3%, 4.3%, -5.1%, and -3.9% respectively, whereas the H group showed smaller improvements, (1.7% (P < .05), 1.2% (P < .01), 1.7% (P < .01), and 1.2% (P < .01) respectively). There were no significant changes in the C group. The posture characteristics and the peak anaerobic power (AWT) performance did not change with training in any of the groups.

Conclusion:

The U+D training method was significantly more effective in improving MRS and the kinematic characteristics of sprint running than a traditional horizontal training method.
Placebo Effects of Caffeine on Short-Term Resistance Exercise to Failure
Authors: Duncan Michael J. , Lyons Mark , Hankey Joanne
Published: August 2016

Purpose:

This study examined the placebo effect of caffeine on number of repetitions (reps), rating of perceived exertion (RPE), blood pressure (BP), and peak heart rate (PHR) during resistance-training exercise with repetitions (reps) performed to volitional failure.

Methods:

Following determination of 1-rep maximum in single-leg leg extension, 15 males performed reps to failure at 60% 1-RM in 3 conditions: control, perceived caffeine condition, and perceived placebo condition presented in a randomized order. Participants were informed they would ingest 250 mL of solution that contained either 3 mg·kg−1caffeine or 3 mg·kg−1placebo 1 h before each exercise trial. A deceptive protocol was employed and subjects consumed a placebo solution in both conditions. During each condition, total reps, RPE for the active muscle and overall body, and PHR were recorded.

Results:

Subjects completed 2 more reps when they perceived they had ingested caffeine. RPE was significantly (P= .04) lower in the perceived caffeine and control conditions and RPE for the active muscle was significantly higher across all conditions compared with RPE for the overall body. No substantial differences were evident in PHR across conditions.

Conclusions:

Results of this study are similar to studies of actual caffeine ingestion. However, the perception of consuming a substance that purportedly enhances performance is sufficient enough to enable individuals to complete a greater number of reps to failure during short-term resistance exercise.
High-Intensity Training in Football
Authors: Iaia F. Marcello , Ermanno Rampinini , Bangsbo Jens
Published: August 2016

This article reviews the major physiological and performance effects of aerobic high-intensity and speed-endurance training in football, and provides insight on implementation of individual game-related physical training. Analysis and physiological measurements have revealed that modern football is highly energetically demanding, and the ability to perform repeated high-intensity work is of importance for the players. Furthermore, the most successful teams perform more high-intensity activities during a game when in possession of the ball. Hence, footballers need a high fitness level to cope with the physical demands of the game. Studies on football players have shown that 8 to 12 wk of aerobic high-intensity running training (>85% HRmax) leads to VO2max enhancement (5% to 11%), increased running economy (3% to 7%), and lower blood lactate accumulation during submaximal exercise, as well as improvements in the yo-yo intermittent recovery (YYIR) test performance (13%). Similar adaptations are observed when performing aerobic high-intensity training with small-sided games. Speed-endurance training has a positive effect on football-specific endurance, as shown by the marked improvements in the YYIR test (22% to 28%) and the ability to perform repeated sprints (~2%). In conclusion, both aerobic and speed-endurance training can be used during the season to improve high-intensity intermittent exercise performance. The type and amount of training should be game related and specific to the technical, tactical, and physical demands imposed on each player.
Oxygen Uptake Kinetics: An Underappreciated Determinant of Exercise Performance
Authors: Jones Andrew M. , Burnley Mark
Published: August 2016

The rate at which VO2 adjusts to the new energy demand following the onset of exercise strongly influences the magnitude of the “O2 defcit” incurred and thus the extent to which muscle and systemic homeostasis is perturbed. Moreover, during continuous high-intensity exercise, there is a progressive loss of muscle contractile efficiency, which is reflected in a “slow component” increase in VO2. The factors that dictate the characteristics of these fast and slow phases of the dynamic response of VO2 following a step change in energy turnover remain obscure. However, it is clear that these features of the VO2 kinetics have the potential to influence the rate of muscle fatigue development and, therefore, to affect sports performance. This commentary outlines the present state of knowledge on the characteristics of, and mechanistic bases to, the VO2 response to exercise of different intensities. Several interventions have been reported to speed the early VO2 kinetics and/or reduce the magnitude of the subsequent VO2 slow component, and the possibility that these might enhance exercise performance is discussed.
Reliability of an In-Water Repeated-Sprint Test for Water Polo
Authors: Tan Frankie H. Y. , Polglaze Ted , Dawson Brian
Published: August 2016

Time-motion studies indicate the importance of repeated high-intensity activities during water polo match play. The purpose of this study was to assess the reliability of an in-water repeated-sprint test, which comprised 6 × 10-m all-out sprints, departing every 17 s. This protocol was chosen to replicate the regular intense periods of match play.
Relationship Between Muscle Strength, Power and Stiffness and Running Economy in Trained Male Runners
Authors: Dumke Charles L. , Pfaffenroth Christopher M. , McBride Jeffrey M. , McCauley Grant O.
Published: August 2016

Purpose:

In this study, a comparison was made between muscle strength, power and muscle and tendon (km and kt respectively) stiffness of the triceps surae muscle group and running economy (RE) in trained male runners.

Methods:

Twelve well-trained male runners (age = 21 + 2.7 y, height = 178.1 ± 7.1 cm, body mass = 66.7 + 3.2 kg, VO2 max = 68.3 + 4.3 mLkg–1min–1, 5000-m time = 15:04 min:s) underwent passive stiffness testing using a free oscillation method. Muscle strength was determined via a maximal isometric squat test and power determined via a maximal countermovement jump (CMJ). On a separate day, subjects performed an incremental treadmill test and their RE, lactate threshold, and VO2 max were determined. Fingertip blood lactate was determined at the end of each 3-min stage. Lactate threshold was defined as a nonlinear increase in lactate accumulation.

Results:

A statistically significant correlation was found between k m and VO at stage 6 (r = -0.69, P = .01). In addition, statistically significant correlations were observed between CMJ peak force production and VO2 at stage 2 (r = .66, P = .02), stage 3 (r = .70, P = .01), and stage 4 (r = .58, P = .04). No other statistically significant correlations were observed.

Conclusion:

These data suggest that greater muscle stiffness and less power are associated with greater RE. Future study in this area should focus on determining the mechanisms behind this relationship and how to best apply them to a running population through training techniques.