bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of an Audio-Paced Incremental Swimming Test in Young National-Level Swimmers
Authors: Turner Anthony P. , Smith Taylor , G.S. Coleman Simon
Published: August 2016

Purpose:

To evaluate the reliability and sensitivity to training of an audio-paced incremental swimming test.

Methods:

Eight young national-level male swimmers (age 15 ± 1 year) performed a 7 × 200-m incremental swimming test (velocities 1.19, 1.24, 1.28, 1.33, 1.39, and 1.45 m/s and maximal sprint pace) using an audio-pacing device. The same test was performed 4 times by each participant, 1 wk apart to assess reliability (WK1, WK2) and after 9 and 20 wk of training (WK9, WK20). Blood lactate concentration ([La−]) and heart rate (HR) were recorded after each stage. Outcome measures were the velocity (v) and HR at lactate markers of 2 mM, 4 mM, and Δ1 mM.

Results:

Velocities at the lactate markers proved to be more reliable than HR, with typical errors ranging from 0.66% to 2.30% and 1.28% to 4.50%, respectively (shifts in mean ranged –0.91% to 0.73% and –0.84% to 1.79%, respectively). Across WK1, WK9, and WK20 there were significant improvements in peak velocity (P < .001) and each of the velocities associated with the lactate markers (P < .05), whereas only HR at Δ1 mM improved (P < .05).

Conclusions:

This article demonstrates that an audio-paced incremental swimming test is reliable for use with junior swimmers and is sensitive to changes observed after training. The postswimming measurement of HR in the pool was comparatively less reliable.
Effect of Specific Resistance Training on Overarm Throwing Performance
Authors: Ettema Gertjan , Gløsen Tommy , van den Tillaar Roland
Published: August 2016

Purpose:

The main purpose of this study was to compare the effect of a specific resistance training program (throwing movement with a pulley device) with the effect of regular training (throwing with regular balls) on overarm throwing velocity under various conditions.

Methods:

The training forms were matched for total training load, ie, impulse generated on the ball or pulley device. Both training groups (resistance training n = 7 and regular training n = 6) consisted of women team handball players, and trained 3 times per week for 8 weeks, according to an assigned training program alongside their normal handball training.

Results:

An increase in throwing velocity with normal balls after the training period was observed for both groups (P = .014), as well as throwing with heavier balls and throwing like actions in the pulley device. Although the regular training group seemed to improve more (6.1%) in throwing velocity with normal balls than the resistance training group (1.4%), this difference was not statistically significant.

Conclusions:

These findings indicate that resistance training does not surpass standard throwing training in improvement of overarm throwing velocity.
Anaerobic Capacity of the Upper Arms in Top-Level Team Handball Players
Authors: Kounalakis Stylianos N. , Bayios Ioannis A. , Koskolou Maria D. , Geladas Nickos D.
Published: August 2016

Purpose:

Handball is a sport with high anaerobic demands in lower body as has been indicated by Wingate test (WT) performed with the legs, but there are no data available concerning power production during a WT performed with the arms in handball players (HndP). Therefore, the purpose of this study was to explore the arm anaerobic profile of HndP during a WT.

Methods:

Twenty-one elite HndP and 9 physical education students (CON), performed a 30-s arm WT. Power production and muscle oxy-genation were recorded.

Results:

Peak power (PP) as well as mean power (MP) was higher (P = .017 and 0.03, and ES = 1.00 and 0.86, respectively) for HndP (HndP PP: 7.6 ± 0.8 W·kg−1, CON PP: 6.7 ± 1.1 W·kg−1; HndP MP 5.3 ± 0.6 W·kg−1, CON MP 4.6 ± 0.9 W·kg−1) with no significant difference in fatigue index between the two groups. Muscle oxygen saturation (StO2) declined ~30% with exercise with no differences between groups. During recovery the HndP group had higher StO2 (P = .01, ES= 3.04), total hemoglobin and oxygenated hemoglobin compared with the CON group (P < .01 ES = 3.29 and 0.99, respectively). StO2 returned to resting values in 29.5 ± 2.3 s in HndP, whereas this variable did not recover after 2 min in CON.

Conclusions:

The arm anaerobic capacity of the HndP was “excellent,” significantly higher than that by the control group. Moreover, HndP exhibited faster recovery of StO2 compared with the control group. The greater power output and the faster muscle reoxygenation of arms in HndP can be attributed to specific training adaptations related to high performance in handball.
Effect of Short-Term Failure Versus Nonfailure Training on Lower Bod Muscular Endurance
Authors: Willardson Jeffrey M. , Emmett John , Oliver Jon A. , Bressel Eadric
Published: August 2016

Purpose:

This study compared failure versus nonfailure training with equated intensity and volume on lower body muscular endurance in trained men.

Methods:

Each subject performed one lower body workout per week for 6 weeks; the Failure group performed 3 sets of the squat, leg curl, and leg extension exercises to the point of voluntary exhaustion, while the Nonfailure group performed 4 sets for each of these exercises, but with a submaximal number of repetitions that did not allow failure to occur on any set. All subjects performed a pre- and postintervention muscular endurance test that involved 3 sets each for the squat, leg curl, and leg extension exercises. Blood lactate concentration (BL) was assessed before, and at 5 and 10 minutes following the test. Heart rate (HR) was assessed before the test, following the last set of each exercise, and for 10 minutes following the test.

Results:

Both groups demonstrated significant increases in total work (P < .0001) for the postintervention test, with no significant differences between the groups (P = .882). When comparing the pre- and postintervention tests, BL and HR were not significantly different at any time point (P > .05).

Conclusions:

These results indicate that when intensity and volume are equated, failure or nonfailure training results in similar gains in lower body muscular endurance. Therefore, when assessed over relatively short training cycles, the total volume of training might be more important versus whether sets are performed to failure for muscular endurance-related adaptations.
Swimming Performance After Passive and Active Recovery of Various Durations
Authors: Toubekis Argyris G. , Tsolaki Argiro , Smilios Ilias , Douda Helen T. , Kourtesis Thomas , Tokmakidis Savvas P.
Published: August 2016

Purpose:

To examine the effects of active and passive recovery of various durations after a 100-m swimming test performed at maximal effort.

Methods:

Eleven competitive swimmers (5 males, 6 females, age: 17.3 ± 0.6 y) completed two 100-m tests with a 15-min interval at a maximum swimming effort under three experimental conditions. The recovery between tests was 15 min passive (PAS), 5 min active, and 10 min passive (5ACT) or 10 min active and 5 min passive (10ACT). Self-selected active recovery started immediately after the first test, corresponding to 60 ± 5% of the 100-m time. Blood samples were taken at rest, 5, 10, and 15 min after the first as well as 5 min after the second 100-m test for blood lactate determination. Heart rate was also recorded during the corresponding periods.

Results:

Performance time of the first 100 m was not different between conditions (P > .05). The second 100-m test after the 5ACT (64.49 ± 3.85 s) condition was faster than 10ACT (65.49 ± 4.63 s) and PAS (65.89 ± 4.55 s) conditions (P < .05). Blood lactate during the 15-min recovery period between the 100-m efforts was lower in both active recovery conditions compared with passive recovery (P < .05). Heart rate was higher during the 5ACT and 10ACT conditions compared with PAS during the 15-min recovery period (P < .05).

Conclusion:

Five minutes of active recovery during a 15-min interval period is adequate to facilitate blood lactate removal and enhance performance in swimmers. Passive recovery and/or 10 min of active recovery is not recommended.
The Applied Physiology of American Football
Authors: Hoffman Jay R.
Published: August 2016

American football is the most popular sport in the United States. Its popularity is likely related to the intense, fast-paced, physical style of play. The importance of strength and conditioning to success in football has been long understood. In fact, the strength and conditioning profession in North America can take its roots from American football. However, only recently has scientific study confirmed the positive relationships between strength, speed, and power to success in this sport. Although strength and conditioning are integral to every American football program, the collaboration with sport scientists has not been as fruitful. Only limited studies are available examining the physiological effects of actual competition and physiological adaptations or maladaptations during a season of competition. Most studies on American football have primarily focused on physical performance characteristics of these athletes and how various training paradigms can be used to improve performance.
A Review of Fluid and Hydration in Competitive Tennis
Authors: Kovacs Mark S.
Published: August 2016

Hypohydration is known to impair performance and increases the risk of heat injury. Therefore, the consumption of appropriate fluid volumes before, during, and after tennis play is important to maintain physiological homeostasis and performance. Tennis is a sport that typically has points lasting fewer than ten seconds, with short-to-moderate rest periods between each work bout. This sequence is repeated over hours. Most fuid and hydration research has focused on continuous aerobic exercise, which provides vastly different physiological strain compared with tennis practice and competition. Consequently, practical recommendations on maintaining hydration status for aerobic continuous exercise may not be appropriate for tennis athletes. Tennis players can sweat more than 2.5 L·h−1 and replace fluids at a slower rate during competition than in practice. In warm and hot environments, electrolyte-enhanced fluid should be consumed at greater than >200 mL per changeover and ideally closer to 400 mL per changeover. Tennis scientists, coaches, and players need to individualize hydration protocols to arrive at the optimal hydration strategy.
Inference About Magnitudes of Effects
Authors: Barker Richard J. , R. Schofield Matthew
Published: August 2016

In a recent commentary on statistical inference, Batterham and Hopkins1 advocated an approach to statistical inference centered on expressions of uncertainty in parameters. After criticizing an approach to statistical inference driven by null hypothesis testing, they proposed a method of “magnitude-based” inference and then claimed that this approach is essentially Bayesian but with no prior assumption about the true value of the parameter. In this commentary, after we address the issues raised by Batterham and Hopkins, we show that their method is “approximately” Bayesian and rather than assuming no prior information their approach has a very specific, but hidden, joint prior on parameters. To correctly adopt the type of inference advocated by Batterham and Hopkins, sport scientists need to use fully Bayesian methods of analysis.
Sprint Training in Preadolescent Soccer Players
Authors: Venturelli Massimo , Bishop David , Pettene Lorenzo
Published: August 2016

Young soccer players are usually trained with adult-training methods, even though the physiological adaptations are likely to be very different compared with adults. In contrast, some have suggested training preadolescents only with coordination training. The purpose of this study was to investigate whether coordination or repeated-sprint training better improved speed over 20 m, with and without the ball. Sixteen soccer players (mean age 11 ± 0.5 y) were randomly assigned to a sprint-training group (STG = 7) or a coordination-training group (CTG = 9). The STG trained twice a week for 12 wk and performed 20 repetitions of 20- and 10-m sprints; the CTG performed coordination training (eg, speed ladder running) for the same training duration. Maximal jump height, anthropometric measures, and 20-m sprint time, with and without ball, were evaluated before and after the training period. Statistical significance was determined using two-way ANOVA with repeated measure and Pearson test for correlation. Both groups improved speed without the ball: STG = 3.75 ± 0.10 s to 3.66 ± 0.09 s (P < .05); CTG = 3.64 ± 0.13 s to 3.56 ± 0.13 s (P < .05), with no difference between groups. Sprint time with the ball pre- and posttraining was 4.06 ± 0.11 s and 4.05 ± 0.19 s (P > .05) for STG and 4.04 ± 0.12 s and 3.82 ± 0.15 s (P < .05) for CTG, with a significant difference between groups posttraining (P < .05). There were significant correlations between sprint time without ball, CMJ, and SJ. These data suggest that coordination training increases the speed with the ball more than typical repeated-sprint training. It can be hypothesized that running speed with ball improved more in CTG because this particular action requires improvements in coordination.
Inspiratory Muscle Training and Endurance: A Central Metabolic Control Perspective
Authors: Edwards Andrew M. , Walker Raewyn E.
Published: August 2016

The efficacy of inspiratory muscle training (IMT) has been the subject of considerable controversy in terms of whether it is beneficial to endurance athletes and because a convincing physiological rationale has not been identified to explain its mechanism of action. Early studies suggested that IMT was an ineffectual intervention for gains in either maximal aerobic power or endurance-specific performance. More rigorous recent research supports the observation that maximal aerobic power is not receptive to IMT; however, closer evaluation of both early and contemporary research indicates that responses to endurance-specific performance tests are sensitive to IMT. As the aim of endurance training is to improve endurance performance rather than maximal aerobic power, it is plausible that IMT may be useful in specific performance-related circumstances. Performance adaptations following IMT appear to be connected with post training reports of attenuated effort sensations, but this common observation has tended to be overlooked by researchers in preference for a reductionist explanation. This commentary examines the pertinent research and practical performance implications of IMT from the holistic perspective of complex central metabolic control.
Improved Race Performance in Elite Middle-Distance Runners After Cumulative Altitude Exposure
Authors: Saunders Philo U. , Telford Richard D. , Pyne David B. , Gore Christopher J. , Hahn Allan G.
Published: August 2016

We quantified the effect of an extended live high-train low (LHTL) simulated altitude exposure followed by a series of training camps at natural moderate altitude on competitive performance in seven elite middle-distance runners (Vo2max 71.4 ± 3.4 mL·min−1·kg−1, mean ± SD). Runners spent 44 ± 7 nights (mean ± SD) at a simulated altitude of 2846 ± 32 m, and a further 4 X 7- to 10-d training at natural moderate altitude (1700–2200 m) before racing. The combination of simulated LHTL and natural altitude training improved competitive performance by 1.9% (90% confidence limits, 1.3-2.5%). Middle-distance runners can confidently use a combination of simulated and natural altitude to stimulate adaptations responsible for improving performance.
Influence of Hypohydration on Intermittent Sprint Performance in the Heat
Authors: Maxwell Neil S. , Mackenzie Richard W.A. , Bishop David
Published: August 2016

Purpose:

To examine the effect of hypohydration on physiological strain and intermittent sprint exercise performance in the heat (35.5 ± 0.6°C, 48.7 ± 3.4% relative humidity).

Methods:

Eight unacclimatized males (age 23.4 ± 6.2 y, height 1.78 ± 0.04 m, mass 76.8 ± 7.7 kg) undertook three trials, each over two days. On day 1, subjects performed 90 min of exercise/heat-induced dehydration on a cycle ergometer, before following one of three rehydration strategies. On day 2, subjects completed a 36-min cycling intermittent sprint test (IST) with a -0.62 ± 0.74% (euhydrated, EUH), -1.81 (0.99)% (hypohydrated1, HYPO1), or -3.88 ± 0.89% (hypohydrated2, HYPO2) body mass defcit.

Results:

No difference was observed in average total work (EUH, 3790 ± 556 kJ; HYPO1, 3785 ± 628 kJ; HYPO2, 3647 ± 339 kJ, P = 0.418), or average peak power (EUH, 1315 ± 129 W; HYPO1, 1304 ± 175 W; HYPO2, 1282 ± 128 W, P = 0.356) between conditions on day 2. Total work and peak power output in the sprint immediately following an intense repeated sprint bout during the IST were lower in the HYPO2 condition. Physiological strain index was greater in the HYPO2 vs. the EUH condition, but without changes in metabolic markers.

Conclusion:

A greater physiological strain was observed with the greatest degree of hypohydration; however, sprint performance only diminished in the most hypohydrated state near the end of the IST, following an intense bout of repeating sprinting.
The Effect of Carbohydrate Ingestion on the Interleukin-6 Response to a 90-Minute Run Time Trial
Authors: Robson-Ansley Paula , Barwood Martin , Eglin Clare , Ansley Les
Published: August 2016

Fatigue is a predictable outcome of prolonged physical activity; yet its biological cause remains uncertain. During exercise, a polypeptide messenger molecule inter-leukin-6 (IL-6) is actively produced. Previously, it has been demonstrated that administration of recombinant IL-6 (rhIL-6) impairs 10-km run performance and heightened sensation of fatigue in trained runners. Both high carbohydrate diets and carbohydrate ingestion during prolonged exercise have a blunting effect on IL-6 levels post endurance exercise. We hypothesized that carbohydrate ingestion may improve performance during a prolonged bout of exercise as a consequence of a blunted IL-6 response. Seven recreationally trained fasted runners completed two 90-min time trials under CHO supplemented and placebo conditions in a randomized order. The study was of a double-blinded, placebo-controlled, cross-over study design. Distance covered in 90 min was significantly greater following exogenous carbohydrate ingestion compared with the placebo trial (19.13 ± 1.7 km and 18.29 ± 1.9 km, respectively, p = .0022). While post exercise IL-6 levels were significantly lower in the CHO trial compared with the placebo trial (5.3 ± 1.9 pg·mL−1 and 6.6 ± 3.0 pg·mL−1, respectively; p = .0313), this difference was considered physiologically too small to mediate the improvement in time trial performance.
Comparison of Progressive Maximal Swimming Tests in Elite Female Water Polo Players
Authors: Tan Frankie H.Y. , Polglaze Ted , Dawson Brian
Published: August 2016

Purpose:

To compare the Multistage Shuttle Swim Test (MSST), Water Polo Intermittent Shuttle Test (WIST) and 5 × 200 m Incremental Swimming Test (IST) responses in elite female water polo players.

Methods:

Fourteen Australian Women’s National Water Polo Squad members performed the MSST and WIST, and 13 players from a National Water Polo League club performed the IST, MSST and WIST on separate occasions (no goalkeepers were involved). Peak heart rate, blood lactate and ratings of perceived exertion were obtained for all tests. Expired air was collected following all tests for the National League players.

Results:

The National Squad players scored significantly better (ie, distance covered) in the MSST and WIST than the National League players (effect sizes = 1.60 to 1.79, P < .001). The MSST and WIST scores were significantly correlated (r = .80 to 0.88, P < .001). The MSST scores were significantly correlated with peak oxygen uptake (VO2peak; mL·kg−1·min−1) obtained for all tests (r = .58 to 0.59, P < .05). In contrast, there were no significant correlations between the WIST scores and VO2peak obtained for any of the tests (r = .43 to 0.52, P > .05). Differences in VO2peak for the IST, MSST and WIST were nonsignificant (P > .05).

Conclusions:

The MSST and WIST can discriminate players of different competition standards. The MSST can be used to estimate a player’s aerobic fitness and peak heart rate. The WIST appears to better mimic the intermittent activity pattern of the game, but its application to female players, to assess maximal intermittent endurance swimming performance, requires further evaluation.
Recovery of Voluntary and Evoked Muscle Performance Following Intermittent-Sprint Exercise in the Heat
Authors: Duffield Rob , King Monique , Skein Melissa
Published: August 2016

Purpose:

This study investigated the effects of hot conditions on the acute recovery of voluntary and evoked muscle performance and physiological responses following intermittent exercise.

Methods:

Seven youth male and six female team-sport athletes performed two sessions separated by 7 d, involving a 30-min exercise protocol and 60-min passive recovery in either 22°C or 33°C and 40% relative humidity. The exercise protocol involved a 20-s maximal sprint every 5 min, separated by constant-intensity exercise at 100 W on a cycle ergometer. Maximal voluntary contraction (MVC) and a resting evoked twitch (Pf) of the right knee extensors were assessed before and immediately following exercise and again 15, 30, and 60 min post exercise, and capillary blood was obtained at the same time points to measure lactate, pH, and HCO3. During and following exercise, core temperature, heart rate and rating of perceived exertion (RPE) were also measured.

Results:

No differences (P = 0.73 to 0.95) in peak power during repeated sprints were present between conditions. Post exercise MVC was reduced (P < .05) in both conditions and a moderate effect size (d = 0.60) indicated a slower percentage MVC recovered by 60 min in the heat (83 ± 10 vs 74 ± 11% recovered). Both heart rate and core temperature were significantly higher (P < .05) during recovery in the heat. Capillary blood values did not differ between conditions at any time point, whereas sessional RPE was higher 60 min post exercise in the heat.

Conclusions:

The current data suggests that passive recovery in warm temperatures not only delays cardiovascular and thermal recovery, but may also slow the recovery of MVC and RPE.
Development of a Simulated Round of Golf
Authors: Hayes Philip R. , van Paridon Kjell , French Duncan N. , Thomas Kevin , Gordon Dan A.
Published: August 2016

Purpose:

The aim of this study was to develop a laboratory-based treadmill simulation of the on-course physiological demands of an 18-hole round of golf and to identify the underlying physiological responses.

Methods:

Eight amateur golfers completed a round of golf during which heart rate (HR), steps taken, and global positioning system (GPS) data were assessed. The GPS data were used to create a simulated discontinuous round on a treadmill. Steps taken and HR were recorded during the simulated round.

Results:

During the on-course round, players covered a mean (±SD) of 8,251 ± 450 m, taking 12,766 ± 1,530 steps. The mean exercise intensity during the on-course round was 31.4 ± 9.3% of age-predicted heart rate reserve (%HRR) or 55.6 ± 4.4% of age-predicted maximum HR (%HRmax). There were no significant differences between the simulated round and the on-course round for %HRR (P = .537) or %HR max (P = .561) over the entire round or for each individual hole. Furthermore, there were no significant differences between the two rounds for steps taken. Typical error values for steps taken, HR, %HRmax, and %HRR were 1,083 steps, ±7.6 b·min-1, ±4.5%, and ±8.1%, respectively.

Conclusion:

Overall, the simulated round of golf successfully recreated the demands of an on-course round. This simulated round could be used as a research tool to assess the extent of fatigue during a round of golf or the impact of various interventions on golfers.
Talent Development in Adolescent Team Sports: A Review
Authors: Burgess Darren J. , Naughton Geraldine A.
Published: August 2016

Traditional talent development pathways for adolescents in team sports follow talent identification procedures based on subjective games ratings and isolated athletic assessment. Most talent development models are exclusive rather than inclusive in nature. Subsequently, talent identification may result in discontentment, premature stratification, or dropout from team sports. Understanding the multidimensional differences among the requirements of adolescent and elite adult athletes could provide more realistic goals for potential talented players. Coach education should include adolescent development, and rewards for team success at the adolescent level should reflect the needs of long-term player development. Effective talent development needs to incorporate physical and psychological maturity, the relative age effect, objective measures of game sense, and athletic prowess. The influences of media and culture on the individual, and the competing time demands between various competitions for player training time should be monitored and mediated where appropriate. Despite the complexity, talent development is a worthy investment in professional team sport.
Prolonged Repeated-Sprint Ability Is Related to Arterial O2 Desaturation in Men
Authors: Billaut François , Smith Kurt
Published: August 2016

The ability to repeatedly generate maximum power output is usually accompanied by neuromuscular adjustments.

Purpose:

This study aimed to explore the occurrence of arterial O2desaturation during prolonged repeated-sprint ability (RSA) testing and its relationship to neuromuscular activity, as evidenced by changes in surface integrated electromyogram (iEMG).

Methods:

Fifteen, national-level soccer players performed twenty 5-s cycle sprints (25 s of rest). Mechanical work and surface iEMG of the vastus lateralis (VL) and rectus femoris (RF) of the dominant lower limb were recorded for every sprint. Arterial O2saturation (S O2) was estimated via pulse oximetry and rating of perceived exertion (RPE) recorded immediately after every sprint.

Results:

Over the sprints, mechanical work (23.5%), iEMG (VL: 14.2%, RF: 16.4%) and S O2 (3.5%) decreased, and RPE progressed to 19 (allP< .05). There was a strong linear relationship (R2= .83,P <.05) between the changes in mechanical output and iEMG during the sprints. More importantly, changes in S O2accompanied changes in mechanical work, iEMG and RPE (R2= .68,R2= .64,R2= .62,P <.05, respectively).

Conclusion:

The study suggests that in a homogenous group of athletes a progressive arterial O2 desaturation develops during a prolonged RSA test, which may contribute toward performance regulation via an effect on sense of effort and neuromuscular activity.
Variation in Performance Times of Elite Flat-Water Canoeists From Race to Race
Authors: Bonetti Darrell L. , Hopkins Will G.
Published: August 2016

Purpose:

To estimate variability in performance time and smallest worthwhile changes for elite fat-water canoeists competing in 200-, 500- or 1000-m events at international regattas.

Methods:

The data came from A and B finals held at 7 to 13 regattas in 2003 to 2007. A linear mixed-model analysis of log-transformed official race times provided estimates of variability as coefficients of variation and included terms to account for changes in performance between years, venues, and A and B finals.

Results:

For men, the within-athlete variation in A finals was similar in canoeing and kayaking events, with the 200-m men’s events demonstrating probably less variability than the longer events (by an overall factor of 0.75, ×/÷1.33) that may reflect differences in pacing strategies. In contrast, the within-athlete variation for women kayakers in A finals of the 500-m event was only half that of the other distances (ratio 0.54, ×/÷1.29), possibly because of differences in competitive experience or depth of competition. Predictability of performance in A finals was moderate to very high (interclass correlations 0.40 to 0.89). Within-athlete variation in the B finals was generally greater than in the A finals for the three distances for men, but there was no clear pattern for women.

Conclusion:

The smallest worthwhile changes in performance time (0.3× within-athlete variability) in canoeing and kayaking are approx. 0.3% to 0.6%. Effects of 1% to 2% in power output would be required to achieve such changes in this generally highly predictable sport.
A Comparison of the Physiological Demands of Wheelchair Basketball and Wheelchair Tennis
Authors: Croft Louise , Dybrus Suzanne , Lenton John , Goosey-Tolfrey Victoria
Published: August 2016

Purpose:

To examine the physiological profiles of wheelchair basketball and tennis and specifically to: (a) identify if there are differences in the physiological profiles of wheelchair basketball and tennis players of a similar playing standard, (b) to determine whether the competitive physiological demands of these sports differed (c) and to explore the relationship between the blood lactate [Bla−] response to exercise and to identify the sport specific heart rate (HR) training zones.

Methods:

Six elite athletes (4 male, 2 female) from each sport performed a submaximal and VO2 peak test in their sport specific wheelchair. Heart rate, VO2, and [Bla−] were measured. Heart rate was monitored during international competitions and VO2 was calculated from this using linear regression equations. Individual HR training zones were identified from the [Bla–] profile and time spent within these zones was calculated for each match.

Results:

Despite no differences in the laboratory assessment of HRpeak, the VO2peak was higher for the basketball players when compared with the tennis players (2.98 ± 0.91 vs 2.06 ± 0.71; P = .08). Average match HR (163 ± 11 vs 146 ± 16 beats-min–1; P = .06) and average VO2 (2.26 ± 0.06 vs 1.36 ± 0.42 L-min-1; P = .02) were higher during actual playing time of basketball when compared with whole tennis play. Consequently, differences in the time spent in the different training zones within and between the two sports existed (P < .05).

Conclusions:

Wheelchair basketball requires predominately high-intensity training, whereas tennis training requires training across the exercise intensity spectrum.
Sweat Rate and Electrolyte Concentration in Swimmers, Runners, and Nonathletes
Authors: Henkin Simone D. , Sehl Paulo L. , Meyer Flavia
Published: August 2016

Because swimmers train in an aquatic environment, they probably do not need to sweat as much as runners who train on land and, therefore, should not develop the same magnitude of sweating adaptations.

Purpose:

To compare sweat rate and electrolyte concentration in swimmers, runners and nonathletes.

Methods:

Ten swimmers (22.9 ± 3.1 years old), 10 runners (25 ± 2.9 y) and 10 nonathletes (26.5 ± 2.2 y) cycled in the heat (32°C and 40% relative humidity) for 30 min at similar intensity relative to their maximal cycle test. Sweat volume was calculated from the difference of their body mass before and after cycling, since they were not allowed to drink. Sweat was collected from the scapula using absorbent patch placed on the skin that was cleaned with distilled water. After cycling, the patch was transferred to syringe and the sample was obtained when squeezing it to a tube. Concentration of sodium ([Na+]), chloride ([Cl–]) and potassium ([K+]) were analyzed using an ion selector analyzer.

Results:

The sweat volume, in liters, of swimmers (0.9 ± 0.3) was lower (P < .05) than that of runners (1.5 ± 0.2) and similar to that of nonathletes (0.6 ± 0.2). [Na+] and [Cl-], in mmolL-1, of swimmers (65.4 ± 5.5 and 61.2 ± 81), and nonathletes (67.3 ± 8.5 and 58.3 ± 9.6) were higher (P < .05) than those of runners (45.2 ± 7.5 and 38.9 ± 8.3). [K+] was similar among groups.

Conclusions:

The lower sweat volume and higher sweat [Na+] and [Cl-] of swimmers, as compared with runners, indicate that training in the water does not cause the same magnitude of sweating adaptations.
The Validity and Reliability of 1-Hz and 5-Hz Global Positioning Systems for Linear, Multidirectional, and Soccer-Specific Activities
Authors: Portas Matthew D. , Harley Jamie A. , Barnes Christopher A. , Rush Christopher J.
Published: August 2016

Purpose:

The study aimed to analyze the validity and reliability of commercially available nondifferential Global Positioning System (NdGPS) devices for measures of total distance during linear, multidirectional and soccer-specific motion at 1-Hz and 5-Hz sampling frequencies.

Methods:

Linear (32 trials), multidirectional (192 trials) and soccer-specific courses (40 trials) were created to test the validity (mean ± 90% confidence intervals), reliability (mean ± 90% confidence intervals) and bias (mean ± 90% confidence intervals) of the NdGPS devices against measured distance. Standard error of the estimate established validity, reliability was determined using typical error and percentage bias was established.

Results:

The 1-Hz and 5-Hz data ranged from 1.3% ± 0.76 to 3.1% ± 1.37 for validity and 2.03% ± 1.31 to 5.31% ± 1.2 for reliability for measures of linear and soccer-specific motion. For multidirectional activity, data ranged from 1.8% ± 0.8 to 6.88% ± 2.99 for validity and from 3.08% ± 1.34 to 7.71% ± 1.65 for reliability. The 1-Hz underestimated some complex courses by up to 11%.

Conclusions:

1-Hz and 5-Hz NdGPS could be used to quantify distance in soccer and similar field-based team sports. Both 1-Hz and 5-Hz have a threshold beyond which reliability is compromised. 1-Hz also underestimates distance and is less valid in more complex courses.
The Influence of Elliptical Chainrings on 10 km Cycling Time Trial Performance
Authors: Peiffer Jeremiah J. , Abbiss Chris R.
Published: August 2016

The use of elliptical chainrings (also called chainwheels or sprockets) has gained considerable interest in the amateur and professional cycling community. Nevertheless, we are unaware of any scientific studies that have examined the performance benefits of using elliptical chainrings during an actual performance trial. Therefore, this study examined the influence of elliptical chainring use on physiological and performance parameters during a 10 km cycling time trial. Nine male cyclists completed, in a counterbalanced order, three 10 km cycling time trials using either a standard chainring or an elliptical chainring at two distinct settings. An attempt was made to blind the cyclists to the type of chainring used until the completion of the study. During the 10 km time trial, power output and heart rate were recorded at a frequency of 1 Hz and RPE was measured at 3, 6, and 8.5 km. Total power output was not different (P = .40) between the circular (340 ± 30 W) or either elliptical chainring condition (342 ± 29 W and 341 ± 31 W). Similarly, no differences (P = .73) in 2 km mean power output were observed between conditions. Further, no differences in RPE were observed between conditions measured at 3, 6, and 8.5 km. Heart rate was significantly greater (P = .02) using the less aggressive elliptical setting (174 ± 10 bpm) compared with the circular setting (171 ± 9 bpm). Elliptical chainrings do not appear to provide a performance benefit over traditional circular chainrings during a mid-distance time trial.
Which Jump Variables Should Be Used to Assess Explosive Leg Muscle Function?
Authors: Young Warren , Cormack Stuart , Crichton Michael
Published: August 2016

Purpose:

The main purpose of this study was to determine the relationships between countermovement jump (CMJ) variables and acceleration and maximum speed performance.

Methods:

Twenty-three elite Australian football players were tested on a CMJ, which yielded several kinematic and kinetic variables describing leg muscle function. A 40 m sprint was also conducted to assess acceleration (10 m time) and an estimate of maximum speed (fying 20 m time). Players from one Australian Football League (AFL) club were tested and Pearson correlations for CMJ variables and sprint performance were calculated.

Results:

Jump height, peak velocity, peak force, and peak power had less than 50% common variance, and therefore represented independent expressions of CMJ performance. Generally, the correlations between CMJ variables and sprinting performance were stronger for maximum speed (small to large effect sizes) than for acceleration (trivial to moderate sizes). The variable that produced the strongest correlation with acceleration was jump height (r = -0.430, P = .041) and with maximum speed was peak power/weight (r = -0.649, P = .001).

Conclusions:

The results indicate that if an integrated system comprising a position transducer and a force platform is available for CMJ assessment, jump height and peak power/weight are useful variables to describe leg muscle explosive function for athletes who perform sprints.
Applications of GPS Technologies to Field Sports
Authors: Aughey Robert J.
Published: August 2016

Global positioning system (GPS) technology was made possible after the invention of the atomic clock. The first suggestion that GPS could be used to assess the physical activity of humans followed some 40 y later. There was a rapid uptake of GPS technology, with the literature concentrating on validation studies and the measurement of steady-state movement. The first attempts were made to validate GPS for field sport applications in 2006. While GPS has been validated for applications for team sports, some doubts continue to exist on the appropriateness of GPS for measuring short high-velocity movements. Thus, GPS has been applied extensively in Australian football, cricket, hockey, rugby union and league, and soccer. There is extensive information on the activity profile of athletes from field sports in the literature stemming from GPS, and this includes total distance covered by players and distance in velocity bands. Global positioning systems have also been applied to detect fatigue in matches, identify periods of most intense play, different activity profiles by position, competition level, and sport. More recent research has integrated GPS data with the physical capacity or fitness test score of athletes, game-specific tasks, or tactical or strategic information. The future of GPS analysis will involve further miniaturization of devices, longer battery life, and integration of other inertial sensor data to more effectively quantify the effort of athletes.
Development of a Soccer Simulation Protocol to Include Repeated Sprints and Agility
Authors: Stone Keeron J. , Oliver Jonathan L. , Hughes Michael G. , Stembridge Michael R. , Newcombe Daniel J. , Meyers Robert W.
Published: August 2016

Existing procedures for the simulation of soccer match play fail to incorporate multidirectional and repeated-sprint activities, even though these movements are considered fundamental to match play. In the current study, selected physiological and performance responses were assessed during an adapted version of an existing soccer simulation protocol. Mean heart rates of 163 ± 14 beats·min–1, mean blood lactates of 4.9 ± 2.3 mmol·L-1 and decrements in single-sprint and repeated-sprint performances were observed. The presented adaptations to an existing soccer simulation protocol better reflect the movement characteristics as well as the physiological and performance responses of soccer match play.
The Challenge of Performing Aerobic Exercise in Tropical Environments: Applied Knowledge and Perspectives
Authors: Hue Olivier
Published: August 2016

The tropical climate is unique in that the seasons are dominated by the movement of the tropical rain belt, resulting in dry and wet seasons rather than the four-season pattern of changes in temperature and day length seen in other parts of the world. More than 33% of the world population lives in the humid tropics, which are characterized by consistently high monthly temperatures and rainfall that exceeds evapotranspiration for most days of the year. Both the 2014 Football World Cup (in Brazil) and the 2016 Olympic Games (in Rio de Janeiro) will take place in this climate. This review focuses on the effects of the tropical environment on human exercise performance, with a special emphasis on prolonged aerobic exercise, such as swimming, cycling, and running. Some of the data were collected in Guadeloupe, the French West Indies Island where all the French teams will be training for the 2016 Olympic Games. We will first fully define the tropical climate and its effects on performance in these sports. Then we will discuss the types of adaptation that help to enhance performance in this climate, as well as the issues concerning the prescription of adequate training loads. We will conclude with some perspectives for future research.
Reliability and Effect of Sodium Bicarbonate: Buffering and 2000-m Rowing Performance
Authors: Carr Amelia J. , Slater Gary J. , Gore Christopher J. , Dawson Brian , Burke Louise M.
Published: August 2016

Purpose:

The aim of this study was to determine the effect and reliability of acute and chronic sodium bicarbonate ingestion for 2000-m rowing ergometer performance (watts) and blood bicarbonate concentration [HCO3−].

Methods:

In a crossover study, 7 well-trained rowers performed paired 2000-m rowing ergometer trials under 3 double-blinded conditions: (1) 0.3 grams per kilogram of body mass (g/kg BM) acute bicarbonate; (2) 0.5 g/kg BM daily chronic bicarbonate for 3 d; and (3) calcium carbonate placebo, in semi-counterbalanced order. For 2000-m performance and [HCO3−], we examined differences in effects between conditions via pairwise comparisons, with differences interpreted in relation to the likelihood of exceeding smallest worthwhile change thresholds for each variable. We also calculated the within-subject variation (percent typical error).

Results:

There were only trivial differences in 2000-m performance between placebo (277 ± 60 W), acute bicarbonate (280 ± 65 W) and chronic bicarbonate (282 ± 65 W); however, [HCO3−] was substantially greater after acute bicarbonate, than with chronic loading and placebo. Typical error for 2000-m mean power was 2.1% (90% confidence interval 1.4 to 4.0%) for acute bicarbonate, 3.6% (2.5 to 7.0%) for chronic bicarbonate, and 1.6% (1.1 to 3.0%) for placebo. Postsupplementation [HCO3−] typical error was 7.3% (5.0 to 14.5%) for acute bicarbonate, 2.9% (2.0 to 5.7%) for chronic bicarbonate and 6.0% (1.4 to 11.9%) for placebo.

Conclusion:

Performance in 2000-m rowing ergometer trials may not substantially improve after acute or chronic bicarbonate loading. However, performances will be reliable with both acute and chronic bicarbonate loading protocols.
The Tour de France: An Updated Physiological Review
Authors: Santalla Alfredo , Earnest Conrad P. , Marroyo José A. , Lucia Alejandro
Published: August 2016

From its initial inception in 1903 as a race premised on a publicity stunt to sell newspapers, the Tour de France had grown and evolved over time to become one of the most difficult and heralded sporting events in the world. Though sporting science and the Tour paralleled each other, it was not until the midlate 1980s, and especially the midlate 1990s (with the use of heart-rate monitors) that the 2 began to unify and grow together. The purpose of this brief review is to summarize what is currently known of the physiological demands of the Tour de France, as well as of the main physiological profile of Tour de France competitors.
Salivary Immunoglobulin A and Upper Respiratory Symptoms During 5 Months of Training in Elite Tetraplegic Athletes
Authors: Leicht Christof A. , Bishop Nicolette C. , Paulson Thomas A.W. , Griggs Katy E. , Goosey-Tolfrey Victoria L.
Published: August 2016

Purpose:

Altered autonomic innervation in tetraplegic individuals has been shown to depress certain immune parameters at rest and alter exercise-related salivary immunoglobulin A (sIgA) responses. The purpose of this study was to examine resting sIgA responses as a function of training load and episodes of upper respiratory symptoms (URS) in elite tetraplegic athletes.

Methods:

Resting saliva samples were obtained from 14 tetraplegic athletes at 12 predefined time points over 5 months and analyzed for sIgA. Occurrence of self-reported URS and training load was recorded throughout the study’s duration. Regression analyses were performed to investigate the relationship between sIgA responses and training load. Furthermore, the relationships between sIgA responses and URS occurrence were examined.

Results:

sIgA secretion rate was negatively correlated with training load (P = .04), which only accounted for 8% of the variance. No significant relationships were found between sIgA responses and subsequent URS occurrence. Finally, sIgA responses did not differ between athletes with and without recorded URS during the study period.

Conclusions:

In line with findings in ablebodied athletes, negative relationships between sIgA secretion rate and training load were found in tetraplegic athletes. This may explain some of the higher infection risk in wheelchair athletes with a high training load, which has been previously observed in paraplegic athletes. However, the nonsignificant relationship between sIgA responses and URS occurrence brings into question the use of sIgA as a prognostic tool for the early detection of URS episodes in the studied population.
Talent Identification and Specialization in Sport: An Overview of Some Unanswered Questions
Authors: Gonçalves Carlos E.B. , Rama Luís M.L. , Figueiredo António B.
Published: August 2016

The theory of deliberate practice postulates that experts are always made, not born. This theory translated to the youth-sport domain means that if athletes want to be high-level performers, they need to deliberately engage in practice during the specialization years, spending time wisely and always focusing on tasks that challenge current performance. Sport organizations in several countries around the world created specialized training centers where selected young talents practice under the supervision of experienced coaches in order to become professional athletes and integrate onto youth national teams. Early specialization and accurate observation by expert coaches or scouts remain the only tools to find a potential excellent athlete among a great number of participants. In the current study, the authors present 2 of the problems raised by talent search and the risks of such a search. Growth and maturation are important concepts to better understand the identification, selection, and development processes of young athletes. However, the literature suggests that sport-promoting strategies are being maintained despite the increased demands in the anthropometric characteristics of professional players and demands of actual professional soccer competitions. On the other hand, identifying biological variables that can predict performance is almost impossible.