bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effects of Chronic Sodium Bicarbonate Ingestion and Interval Training in Highly Trained Rowers
Authors: Driller Matthew W. , Gregory John R. , Williams Andrew D. , Fell James W.
Published: August 2016

Recent research has reported performance improvements after chronic NaHCO3 ingestion in conjunction with high-intensity interval training (HIT) in moderately trained athletes. The purpose of the current study was to determine the effects of altering plasma H+ concentration during HIT through NaHCO3 ingestion over 4 wk (2 HIT sessions/wk) in 12 Australian representative rowers (M ± SD; age 22 ± 3 yr, mass 76.4 ± 4.2 kg, VO2peak 65.50 ± 2.74 ml · kg−1 · min−1). Baseline testing included a 2,000-m time trial and an incremental exercise test. After baseline testing, rowers were allocated to either a chronic NaHCO3 (ALK) or placebo (PLA) group. Starting 90 min before each HIT session, subjects ingested a 0.3-g/kg body mass dose of NaHCO3 or a placebo substance. Fingertip blood samples were taken throughout the study to analyze bicarbonate and pH levels. The ALK group did not produce any additional improvements in 2,000-m rowing performance time compared with PLA (p > .05). Magnitude-based inferential analysis indicated an unclear or trivial effect on 2,000-m power, 2,000-m time, peak power output, and power at 4 mmol/L lactate threshold in the ALK group compared with the PLA group. Although there was no difference between groups, during the study there was a significant mean (± SD) 2,000-m power improvement in both the ALK and PLA groups of 17.8 ± 14.5 and 15.2 ± 18.3 W, respectively. In conclusion, despite overall improvements in rowing performance after 4 wk of HIT, the addition of chronic NaHCO3 supplementation during the training period did not significantly enhance performance further.
Opposition of Carbohydrate in a Mouth-Rinse Solution to the Detrimental Effect of Mouth Rinsing During Cycling Time Trials
Authors: Gam Sharon , Guelfi Kym J. , Fournier Paul A.
Published: August 2016

Studies have reported that rinsing the mouth with a carbohydrate (CHO) solution improves cycling time-trial performance compared with rinsing with a placebo solution. However, no studies have compared the effect of mouth rinsing with a no-mouth-rinse control condition. The aim of this study was to compare the effects of a CHO mouth rinse with those of a placebo rinse and a no-rinse condition. Ten male cyclists completed three 1,000-kJ cycling time trials in a randomized, counterbalanced order. At every 12.5% of the time trial completed, participants were required to rinse their mouths for 5 s with either a 6.4% maltodextrin solution (CHO), water (WA), or no solution (CON). Heart rate and ratings of perceived exertion (RPE) were recorded every 25% of the time trial completed. Time to completion was faster in both CHO (65.7 ± 11.07 min) and CON (67.6 ± 12.68 min) than in WA (69.4 ± 13.81 min; p = .013 and p = .042, respectively). The difference between CHO and CON approached significance (p = .086). There were no differences in heart rate or RPE between any conditions. In summary, repeated mouth rinsing with water results in decreased performance relative to not rinsing at all. Adding CHO to the rinse solution appears to oppose this fall in performance, possibly providing additional benefits to performance compared with not rinsing the mouth at all. This brings into question the magnitude of the effect of CHO mouth rinsing reported in previous studies that did not include a no-rinse condition.
Effects of DHA-Rich Fish Oil Supplementation on Lymphocyte Function Before and After a Marathon Race
Authors: Santos Vinicius Coneglian , Levada-Pires Adriana Cristina , Alves Sâmia Rocha , Pithon-Curi Tânia Cristina , Curi Rui , Cury-Boaventura Maria Fernanda
Published: August 2016

Purpose:

To investigate the effects of docosahexaenoic-(DHA)-rich fish oil (FO) supplementation on lymphocyte function before and after a marathon race.

Methods:

Twenty-one athletes participated in this study. Eight marathon runners were supplemented with 3 g of FO daily for 60 d (FO group), and 13 athletes were not supplemented (C group). The following measures of lymphocytes were taken before and after the marathon: cell proliferation, cytokine production (IL-2, IL-10, TNF-α, and IL-4), and signs of cell death.

Results:

In the C group, the marathon had no effect on lymphocyte proliferation, DNA fragmentation, or mitochondrial membrane polarization; however, the marathon increased phosphatidylserine externalization (by 2.5-fold), induced a loss of plasma membrane integrity (by 20%), and decreased IL-2, TNF-α, and IL-10 production (by 55%, 95%, and 50%, respectively). FO supplementation did not prevent lymphocyte death induced by the marathon, as indicated by cell viability, DNA fragmentation, and phosphatidylserine externalization. However, FO supplementation increased lymphocyte proliferation before and after the marathon, and before the race, FO supplementation decreased IL-2, TNF-α, and IL-10 production in concanavalin-A-stimulated lymphocytes (by 55%, 95%, and 58%, respectively) compared with cells from the C group. The production of cytokines was not altered before or after the race in the FO group.

Conclusions:

DHA-rich FO supplementation increased lymphocyte proliferation and prevented a decrease in cytokine production, but it did not prevent lymphocyte death induced by participation in the marathon. Overall, DHA rich-FO supplementation has beneficial effects in preventing some of the changes in lymphocyte function induced by marathon participation.
Predictors of the Relationships Between Nutritional Supplement Use and Weight-Modification Goals of U.S. Army Soldiers
Authors: Austin Krista G. , Carvey Christina E. , Farina Emily K. , Lieberman Harris R.
Published: August 2016

Background:

U.S. Army Soldiers must meet body weight and composition standards and consequently may use nutritional supplements (NS) purported to assist in weight modification (WM). Nutritional supplements are dietary supplements (DS) and foods intended to supplement the diet.

Purpose:

This study assessed relationships between NS use, demographic characteristics, health-related behaviors, and WM goals among U.S. Army personnel.

Methods:

Participants (N = 990) self-reported NS use, categorized as energy drinks, sport nutrition products, or DS, and WM goal (lose, gain, or maintain) was ascertained by survey. DS were subcategorized as health, weight-loss, weight-gain, or other DS. Chi-square and logistic regression were used to assess relationships between predictors, NS use, and WM goal. Most respondents (70.3% ± 1.7%) consumed some NS; however, overall NS use was not related to WM goal. Significant relationships were observed between predictors (tobacco use, age, body-mass index, fitness score, general health, and eating habits) and both WM goal and NS use. Respondents attempting to lose or maintain weight were less likely to consume energy drinks and weight-gain DS.

Conclusion:

WM goal is related to multiple health behaviors including tobacco use, physical fitness score, and self-perception of health and eating behavior. NS are consumed in this population regardless of WM goal.
The Effect of Heat Acclimation on Sweat Microminerals: Artifact of Surface Contamination
Authors: Ely Matthew R. , Kenefick Robert W. , Cheuvront Samuel N. , Chinevere Troy , Lacher Craig P. , Lukaski Henry C. , Montain Scott J.
Published: August 2016

Heat acclimation (HA) reportedly conveys conservation in sweat micromineral concentrations when sampled from arm sweat, but time course is unknown. The observation that comprehensive cleaning of the skin surface negates sweat micromineral reductions during prolonged sweating raises the question of whether the reported HA effect is real or artifact of surface contamination.

Purpose:

To measure sweat mineral concentrations serially during HA and determine if surface contamination plays a role in the reported mineral reductions.

Methods:

Calcium (Ca), copper (Cu), magnesium (Mg), and zinc (Zn) were measured in sweat obtained from 17 male volunteers using an arm bag on Day 1, 5, and 10 of a HA protocol. To study the role of contamination, sweat was simultaneously (n = 10 subjects) sampled twice daily from a cleaned site (WASH) and unclean site (NO WASH) on the scapular surface.

Results:

Sweat Ca, Cu, and Mg from Arm Bag trended progressively downward from Day 1 to Day 10 of HA (p = .10–0.25). Micromineral concentrations from the WASH site did not change between Day 1, 5, or 10 (Ca = 0.30 ± 0.12 mmol/L, Cu 0.41 ± 0.53 μmol/L; Zn 1.11 ± 0.80 μmol/L). Surface contamination can confound sweat mineral estimates, as sweat Ca and Cu from NO WASH site were initially higher than WASH (p < .05) but became similar to WASH when sampled serially.

Conclusion:

Heat acclimation does not confer reductions in sweat Ca, Cu, Mg, or Zn. When the skin surface is not cleaned, mineral residue inflates initial sweat mineral concentrations. Earlier reports of micromineral reductions during HA may have been confounded by interday cleaning variability.
Are Serum Hepcidin Levels Chronically Elevated in Collegiate Female Distance Runners?
Authors: Ma Xiaoya , Patterson Kaitlyn J. , Gieschen Kayla M. , Bodary Peter F.
Published: August 2016

The prevalence of iron deficiency tends to be higher in athletic populations, especially among endurancetrained females. Recent studies have provided evidence that the iron-regulating hormone hepcidin is transiently increased with acute exercise and suggest that this may contribute to iron deficiency anemia in athletes. The purpose of this study was to determine whether resting serum hepcidin is significantly elevated in highly trained female distance runners compared with a low exercise control group. Due to the importance of the monocyte in the process of iron recycling, monocyte expression of hepcidin was also measured. A single fasted blood sample was collected midseason from twenty female distance runners averaging 81.9 ± 14.2 km of running per week. Ten age-, gender-, and BMI-matched low-exercise control subjects provided samples during the same period using identical collection procedures. There was no difference between the runners (RUN) and control subjects (CON) for serum hepcidin levels (p = .159). In addition, monocyte hepcidin gene expression was not different between the two groups (p = .635). Furthermore, no relationship between weekly training volume and serum hepcidin concentration was evident among the trained runners. The results suggest that hepcidin is not chronically elevated with sustained training in competitive collegiate runners. This is an important finding because the current clinical conditions that link hepcidin to anemia include a sustained elevation in serum hepcidin. Nevertheless, additional studies are needed to determine the clinical relevance of the well-documented, transient rise in hepcidin that follows acute sessions of exercise.
Organ Size Increases With Weight Gain in Power-Trained Athletes
Authors: Miyauchi Sakiho , Oshima Satomi , Asaka Meiko , Kawano Hiroshi , Torii Suguru , Higuchi Mitsuru
Published: August 2016

The purpose of this study was to determine whether overfeeding and high-intensity physical training increase organ mass. We examined this question using cross-sectional and longitudinal studies in which we measured collegiate male American football players. Freshman (n = 10) and senior players in their second and third years of college (n = 17) participated in the cross-sectional study. The same measurements of the same freshman players (n = 10) were assessed after the one-year weight gain period in the longitudinal study. Fat-free mass (FFM), skeletal muscle, and adipose tissue mass were obtained using dual-energy X-ray absorptiometry. Liver, kidney, brain, and heart volumes were calculated using magnetic resonance imaging or echocardiography. Compared with the freshman players, the senior players had 10.8 kg more FFM, and 0.29 kg, 0.08 kg, and 0.09 kg greater liver, heart, and kidney mass, respectively. In the longitudinal study, FFM, liver, heart, and kidney mass of the freshman players increased by 5.2 kg, 0.2 kg, 0.04 kg, and 0.04 kg, respectively, after one year of overfeeding and physical training. On the other hand, the organ-tissue mass to FFM ratio did not change, except for the brain, in either the cross-sectional or longitudinal studies. Our results indicated that the organtissue masses increased with overfeeding and physical training in male collegiate American football players.
Young Men With Poor Cardiorespiratory Fitness Combined With lower Testosterone Have High Levels of Oxidized LDL Lipids—Being Fit Alters This Relationship
Authors: Kosola Jussi , Ahotupa Markku , Kyröläinen Heikki , Santtila Matti , Vasankari Tommi
Published: August 2016

Purpose:

We hypothesized that lower androgen status together with poor physical fitness associates with atherogenic lipid profile and oxidative stress.

Methods:

Volunteered young men (N = 846, mean age 25.1 ± 4.6 years) were categorized into unfit, average fit, and fit groups according to tertiles of maximal oxygen uptake, series of muscle endurance tests, and maximal upper and lower body strength. Furthermore, concentrations of serum testosterone (TT) and free testosterone (FT) were determined to divide participants into lower and higher testosterone (loTT, hiTT) and free testosterone (loFT, hiFT) subgroups, using medians as cut-off points. The participants were divided into subgroups according to Fitness × Testosterone (Unfit/Average Fit/Fit × Low/High TT/FT), and the concentrations of serum lipids and ox-LDL were measured. Results: The loTT/unfit cardiorespiratory subgroup had 29% higher concentration of ox-LDL compared with the loTT/fit cardiorespiratory subgroup (p = .044). The loTT / unfit cardiorespiratory subgroup had a significantly higher ratio of ox-LDL/HDL-cholesterol compared with the other five TT subgroups (p < .05, in all). While ox-LDL showed a gradual form of decrease from unfit to fit in loTT cardiorespiratory subgroups, no differences were seen in muscular fitness or maximal strength (upper and lower body) subgroups.

Conclusions:

Young men with poor cardiorespiratory fitness together with lower levels of TT have higher concentrations of ox-LDL. Good cardiorespiratory fitness combined with lower androgen levels is not related to atherogenic lipid profile. The combination of poor muscular fitness, or maximal muscle strength, and lower TT levels does not cause atherogenic lipid profile.
The Water-Polo Intermittent Shuttle Test: A Match-Fitness Test for Water-Polo Players
Authors: Mujika Iñigo , McFadden Greg , Hubbard Mark , Royal Kylie , Hahn Allan
Published: August 2016

Purpose:

To develop and validate an intermittent match-fitness test for water-polo players.

Methods:

Eight male junior players performed the Water Polo Intermittent Shuttle Test (WIST) twice to assess test reliability. To assess test sensitivity and validity, 104 male and female players from different competition standards and playing positions were tested. Eighteen players performed the WIST 5 times throughout a season to track fitness changes. Twelve players performed the WIST 48 hours before 4 consecutive National League games, and coaches awarded individual match-fitness scores based on game performances to assess the relationship between match fitness and test results. Heart rate (HR) and blood lactate (Lablood) were measured during and after each test, respectively.

Results:

Test–retest performance values were 216 ± 90 vs 229 ± 96 m (r = .98, P = .0001, coefficient of variation [CV] = 5.4%), peak HR 190 ± 8 vs 192 ± 10 bpm (r = .96, P = .0002, CV = 1.2%), and Lablood 7.0 ± 1.8 vs 6.4 ± 1.6 mmol/L (r = .84, P = .0092, CV = 8.8%). Significant differences were observed among different standards of play (range junior regional females 102 ± 10 m, senior international males 401 ± 30 m) and playing positions (field players 305 ± 154 m, center forwards 255 ± 118, goal keepers 203 ± 135 m). Test performance was lower in the early season (344 ± 118 m) than the remainder of the season (range 459 ± 138 to 550 ± 176 m). WIST performance and match-fitness scores correlated for all field players (r = .57, P = .054) but more highly for field players other than center forwards (r = .83, P = .0027).

Conclusions:

The WIST is a reliable, sensitive, and valid match-fitness test for water-polo players. It could become a useful tool to assess the effects of different interventions on match fitness.
Effect of High-Intensity Resistance Training on Performance of Competitive Distance Runners
Authors: Hamilton Ryan J. , Paton Carl D. , Hopkins William G.
Published: August 2016

In a recent study competitive road cyclists experienced substantial gains in sprint and endurance performance when sessions of high-intensity interval training were added to their usual training in the competitive phase of a season. The current study reports the effect of this type of training on performance of 20 distance runners randomized to an experimental or control group for 5 to 7 weeks of training. The experimental group replaced part of their usual competitive-phase training with 10 × 30-minute sessions consisting of 3 sets of explosive single-leg jumps (20 for each leg) alternating with 3 sets of resisted treadmill sprints (5 × 30-second efforts alternating with 30-second recovery). Before and after the training period all runners completed an incremental treadmill test for assessment of lactate threshold and maximum running speed, 2 treadmill runs to exhaustion for prediction of 800- and 1500-m times, and a 5-km outdoor time trial. Relative to the control group, the mean changes (±90% confidence limits) in the experimental group were: maximum running speed, 1.8% (± 1.1%); lactate-threshold speed, 3.5% (±3.4%); predicted 800-m speed, 3.6% (± 1.8%); predicted 1500-m speed, 3.7% (± 3.0%); and 5-km time-trial speed, 1.2% (± 1.1%). We conclude that high-intensity resistance training in the competitive phase is likely to produce beneficial gains in performance for most distance runners.
Assessment of an International Breaststroke Swimmer Using the 7 × 200-m Step Test
Authors: Thompson Kevin , Garland Stephen , Lothian Fiona
Published: August 2016

Thompson and Cooper1 observed that improvements in the swimming speed at 2-mM and 6-mM lactate concentration coincided with improvements in competitive breaststroke performances, whereas Pyne et al2 concluded that changes in swimming speed at lactate threshold were not directly associated with competition performances in a mixed-stroke group of 12 elite swimmers. This case study presents data from eleven (7 × 200 m) step tests over a 3-year period for a world-class 200-m male breaststroke swimmer. Personal-best race times were reduced by 9.5 seconds over this period. For this individual, step-test data provided valuable information with regard to the swimmer’s readiness for performance, health and training status, and nutritional habits.
The Development of a Standardized Skill Assessment for Junior Volleyball Players
Authors: Gabbett Tim J. , Georgieff Boris
Published: August 2016

Purpose:

To develop a skill assessment for junior volleyball players and to evaluate the reliability, validity, and sensitivity of the test for detecting training-induced improvements in skill.

Methods:

Thirty junior volleyball players (mean ± SD age, 15.5 ± 1.0 years) participated in this study. Subjects performed tests of spiking, setting, serving, and passing skills on 2 separate occasions to determine test–retest reliability of accuracy. Two expert coaches evaluated the players’ technique and reevaluated it 1 month after the initial evaluation to determine the intratester reliability for technique measurements. A third expert coach determined the intertester reliability for technique measurements. The validity of the test to discriminate players of different playing abilities was evaluated by testing junior national, state, and novice volleyball players. Finally, each player participated in an 8-week skill-based training program.

Results:

Accuracy measurements and intratester and intertester ratings of players’ technique proved to be highly reproducible (intraclass correlation coefficient, r, .85 to .98, range of typical error of measurement 0.2% to 10.0%). A progressive improvement in skill was observed with increases in playing level, while training-induced improvements were present in all skill tasks.

Conclusions:

These results demonstrate that skill-based testing offers a reliable method of quantifying development and progress in junior volleyball players. In addition, the skill-testing battery was useful in successfully discriminating playing ability among junior volleyball players of varying levels, and it was sensitive to changes in skill with training. These fi ndings demonstrate that skill-based testing is useful for monitoring the development of junior volleyball players.
High-Intensity Kayak Performance After Adaptation to Intermittent Hypoxia
Authors: Bonetti Darrell L. , Hopkins Will G. , Kilding Andrew E.
Published: August 2016

Context:

Live-high train-low altitude training produces worthwhile gains in performance for endurance athletes, but the benefits of adaptation to various forms of artificial altitude are less clear.

Purpose:

To quantify the effects of intermittent hypoxic exposure on kayak performance.

Methods:

In a crossover design with a 6-week washout, we randomized 10 subelite male sprint kayak paddlers to hypoxia or control groups for 3 weeks (5 days/week) of intermittent hypoxic exposure using a nitrogen-filtration device. Each day's exposure consisted of alternately breathing hypoxic and ambient air for 5 minutes each over 1 hour. Performance tests were an incremental step test to estimate peak power, maximal oxygen uptake, exercise economy, and lactate threshold; a 500-m time trial; and 5 × 100-m sprints. All tests were performed on a wind-braked kayak ergometer 7 and 3 days pretreatment and 3 and 10 days post treatment. Hemoglobin concentration was measured at 1 day pretreatment, 5 and 10 days during treatment, and 3 days after treatment.

Results:

Relative to control, at 3 days post treatment the hypoxia group showed the following increases: peak power 6.8% (90% confidence limits, ± 5.2%), mean repeat sprint power 8.3% (± 6.7%), and hemoglobin concentration 3.6% (± 3.2%). Changes in lactate threshold, mean 500-m power, maximal oxygen uptake, and exercise economy were unclear. Large effects for peak power and mean sprint speed were still present 10 days posthypoxia.

Conclusion:

These effects of intermittent hypoxic exposure should enhance performance in kayak racing. The effects might be mediated via changes in oxygen transport.
Relationship Between Running Velocity of 2 Distances and Various Lactate Parameters
Authors: Papadopoulos Charilaos , Doyle J. Andrew , LaBudde Brian D.
Published: August 2016

Purpose:

The purpose of this study was to determine the relationship between various lactate-threshold (LT) definitions and the average running velocity during a 10-km and a 21.1-km time trial (TT).

Methods:

Thirteen well-trained runners completed an incremental maximal exercise test, a 10-km TT, and a 21.1-km TT on a motorized treadmill. Blood samples were collected through a venous catheter placed in an antecubital vein. Pearson's correlation coefficients were used to determine the relationship between the running velocity at the different LT definitions and the average running velocity during each TT. A dependent t test was used to determine statistical differences for the mean lactate response between the 2 running distances.

Results:

The LTDmax, the point on the regression curve that yielded the maximal perpendicular distance to the straight line formed by the 2 endpoints, was the LT definition with the highest correlation for both 10-km (r = .844) and 21.1-km TTs (r = .783). The velocity at the LTDmax was not, however, the velocity closest to the performance velocity for either distance. The mean running velocity at each LT was significantly different and tended to overestimate the mean TT performance velocities. The mean lactate concentration during the 10-km TT (3.52 ± 1.58 mmol) was significantly higher than during the 21.1-km TT (1.86 ± 0.90 mmol).

Conclusion:

These results indicate that a single LT point cannot be reliably associated with different running distances. Furthermore, these data suggest that a different methodology for estimating the LT that considers individual responses might be required for different running distances.
Plyometric Training in Gaelic Games: A Case Study on a County-Level Hurler
Authors: Duncan Michael J.
Published: August 2016

A 10-week plyometrics-based intervention was carried out with a county-level hurler during preseason preparation. The intervention resulted in a number of physiological changes specific to hurling performance. Most notably, it enabled the athlete to complete repeated sprints with less decrement in performance compared with baseline scores.
Autonomic-Nervous-System Activity During the Preparation Phase for the Snatch in Olympic Weight Lifting
Authors: Collet Christian , Guillot Aymeric , Bolliet Olivier , Dittmar André
Published: August 2016

Purpose:

To examine the preparation phase for the snatch lift in Olympic weight lifting. Two behavioral periods were studied, each corresponding to specific mental processes: a stance in front of the bar and placement of hands on the bar. Each period was hypothesized to elicit different responses of autonomic-nervous-system activity.

Methods:

Twelve elite male subjects completed 12 lifts at 90% to 95% of their best grade after warm-up (80% of their best grade). Because peripheral autonomic-nervous-system activity is related to arousal and activation variation, 6 variables were continuously recorded: electrodermal (skin resistance and potential), thermovascular (skin temperature and skin blood flow), and cardiorespiratory (heart rate and respiratory frequency).

Results:

Responses (ie, phasic activities) were evident during the fi rst behavioral period. Decrease in heart rate (mean = 19 beats/min) or in respiratory frequency (mean = 8.6 beats/min) was related to attention processes. These responses were weaker (−0.16°C vs −0.25°C in skin temperature) and shorter (2.7 seconds vs 4.3 seconds in skin resistance) than those recorded during execution. The second phase showed variations in basal levels (mean increase in heart rate of 25%), related to increase in activation, thus attesting the muscle system’s process of preparation for effort.

Conclusion:

Weight lifters separated the preparation phase into 2 stages that were closely matched by different physiological activities. Weight lifting requires participants to share their mental resources among the 2 demanding concentration phases by first focusing their attention on the execution and then mobilizing energizing resources.
The Use of Electrostimulation Exercise in Competitive Sport
Authors: Maffiuletti Nicola A.
Published: August 2016

After a brief introduction on electro stimulation methodology and applications in competitive sport for performance optimization, this technical report presents the principal effects of electro stimulation-induced resistance exercise on neuromus-cular features. The advantages and limitations of this technique compared with those of voluntary exercise training are also discussed.
Fluid and Food Intake During Professional Men’s and Women’s Road-Cycling Tours
Authors: Ebert Tammie R. , Martin David T. , Stephens Brian , McDonald Warren , Withers Robert T.
Published: August 2016

Purpose:

To quantify the fluid and food consumed during a men’s and women’s professional road-cycling tour.

Methods:

Eight men (age 25 ± 5 y, body mass ± 7.4 kg, and height 177.4 ± 4.5 cm) and 6 women (age 26 ± 4 y, body mass ± 5.6 kg, and height 170.4 ± 5.2 cm) of the Australian Institute of Sport Road Cycling squads participated in the study. The men competed in the 6-d Tour Down Under (Adelaide, Australia), and the women, in the 10-d Tour De L’Aude (Aude, France). Body mass was recorded before and immediately after the race. Cyclists recalled the number of water bottles and amount of food they had consumed.

Results:

Men and women recorded body-mass losses of ~2 kg (2.8% body mass) and 1.5 kg (2.6% body mass), respectively, per stage during the long road races. Men had an average fluid intake of 1.0 L/h, whereas women only consumed on average 0.4 L/h. In addition, men consumed CHO at the rate suggested by dietitians (average CHO intake of 48 g/h), but again the women failed to reach recommendations, with an average intake of ~21 g/h during a road stage.

Conclusions:

Men appeared to drink and eat during racing in accordance with current nutritional recommendations, but women failed to reach these guidelines. Both men and women finished their races with a body-mass loss of ~2.6% to 2.8%. Further research is required to determine the impact of this loss on road-cycling performance and thermoregulation.
Using Microtechnology to Monitor Thermal Strain and Enhance Performance in the Field
Authors: Sleivert Gordon G.
Published: August 2016

Wireless microtechnologies are rapidly emerging as useful tools for sport scientists to move their work out of the laboratory and into the field. The purpose of this report is to describe some of the practical aspects of using ingestible radiotelemetric temperature sensors in sport physiology. Information is also presented to demonstrate the utility of this technology in understanding individual differences in coping with environmental stress, optimizing heat adaptation, and fine-tuning competition strategy (pacing). Wireless core-temperature technology has already revolutionized field monitoring of elite athletes training and competing in extreme environments. These technologies are valuable tools for sport scientists to better understand the interaction between the physiology of exercise and the environment.
The Effect of Superoxygenated Water on Blood Gases, Lactate, and Aerobic Cycling Performance
Authors: McNaughton Lars R. , Kenney Steve , Siegler Jason , Midgley Adrian W. , Lovell Ric J. , Bentley David J.
Published: August 2016

Context:

Recently, superoxygenated-water beverages have emerged as a new purported ergogenic substance.

Purpose:

This study aimed to determine the effects of superoxygenated water on submaximal endurance performance.

Methods:

Eleven active male subjects, VO2max 52.6 ± 4.8 mL · kg−1 · min−1, height 180.0 ± 2.0 cm, weight 76.0 ± 7.0 kg, age 24 ± 1.0 y (mean ± SD), completed a 45-min cycle-ergometry exercise test at 70% of their previously predicted maximal power output with a 10-min rest period, followed by a 15-min time trial (TT). Thirty minutes before the exercise test subjects consumed 15 mL of either superoxygenated water (E) or placebo (P; water mixed with low-chlorine solution). Subjects then completed the test again a week later for the other condition (double-blind, randomized). The physiological variables measured during exercise were VO2, VCO2, respiratory-exchange ratio (RER), VE, PO2, PCO2, blood lactate (bLa–), and heart rate (HR). Mean distance covered and the average power output for the 15-min TT were also measured as performance indicators.

Results:

There were no significant differences in VO2, VCO2, RER, VE, bLa−, PO2, and HR (P > .05) during the exercise tests. Neither were there any significant improvements in the total distance covered (P 9.01 ± 0.74 km vs E 8.96 ± 0.68 km, P > .05) or the average power output (P 186.7 ± 35.8 W vs E 179.0 ± 25.9 W, P > .05) during the 15-min TT.

Conclusion:

Based on these results the authors conclude that consuming 15 mL of superoxygenated water does not enhance submaximal or maximal TT cycling performance.
Measurement Agreement (Repeatability) for a Countermovement Jump Protocol Using a Portable Forceplate
Authors: Williams Morgan D. , Bradshaw Elizabeth J. , Maschette Wayne E.
Published: August 2016

This study assessed measurement agreement of jump-height measures derived from a portable forceplate sampling at 500 Hz. Female (n = 42) and male (n = 30) participants (total N = 72, age = 19.7 ± 2.8 y, height = 174.5 ± 9.3 cm, mass = 71.4 ± 12.8 kg) performed 25 separate maximal jump attempts. This incorporated 5 sets of 5 single jumps. One minute of rest was allowed between jump attempts, with a 3-min rest period between sets. For each participant, the best jump height for each set of 5 jumps was kept for analysis. No systematic bias was identified, and the best jump height was stable within participants across all 5 sets of jumps. Therefore, factors such as fatigue and learning did not affect the measures. Females did jump lower (P = < .0001) than their male counterparts, justifying additional analysis of agreement for the 2 gender groups. Heteroscedasticity was found, so ratio limits of agreement (LOAs) were calculated by using the antilog of the log-transformed data. The calculated ratio LOAs were ×/÷ 1.08 for the total group, ×/÷ 1.08 for females, and ×/÷ 1.08 for males. From the calculated ratio LOA, the jump protocol was shown to provide stable measures of jump height. In addition, the ratio LOA can be helpful to interpret findings from research that report jump height derived from the same protocol and assessing participants from the studied population (ie, active university-age male, female, or combined-gender groups).
Defining the Volume and Intensity of Sport Participation in Adolescent Rugby Union Players
Authors: Hartwig Timothy B. , Naughton Geraldine , Searl John
Published: August 2016

Purpose:

Investigating adolescent training loads might help us understand optimal training adaptations. GPS tracking devices and training diaries were used to quantify weekly sport and other physical activity demands placed on adolescent rugby union players and profile typical rugby training sessions.

Methods:

Participants were 75 males age 14 to 18 y who were recruited from rugby teams representing 3 levels of participation: schoolboy, national representative, and a selective sports school talent squad.

Results:

Schoolboy players covered a distance of (mean ± SD) 3511 ± 836 m, representative-squad players 3576 ± 956 m, and talent-squad players 2208 ± 637 m per rugby training session. The representative squad recorded the highest weekly duration of sport and physical activity (515 ± 222 min/wk), followed by the talent squad (421 ± 211 min/week) and schoolboy group (370 ± 135 min/wk). Profiles of individual players identified as group outliers showed participation in up to 3 games and up to 11 training sessions per week, with twice the weekly load of the team averages.

Conclusion:

Optimal participation and performance of adolescent rugby union players might be compromised by many high-load, high-impact training sessions and games and commitments to other sports and physical activities. An improved understanding of monitoring and quantifying load in adolescent athletes is needed to facilitate best-practice advice for player management and training prescription.
Reliability of Measures Obtained During Single and Repeated Countermovement Jumps
Authors: Cormack Stuart J. , Newton Robert U. , McGuigan Michael R. , Doyle Tim L.A.
Published: August 2016

Purpose:

To establish the reliability of various measures obtained during single and repeated countermovement jump (CMJ) performance in an elite athlete population.

Methods:

Two studies, each involving 15 elite Australian Rules Football (ARF) players were conducted where subjects performed two days, separated by one week, of AM and PM trials of either a single (CMJ1) or 5 repeated CMJ (CMJ5). Each trial was conducted on a portable force-plate. The intraday, interday, and overall typical error (TE) and coefficient of variation (CV%) were calculated for numerous variables in each jump type.

Results:

A number of CMJ1 and CMJ5 variables displayed high intraday, interday, and overall reliability. In the CMJ1 condition, mean force (CV 1.08%) was the most reliable variable. In the CMJ5, fight time and relative mean force displayed the highest repeatability with CV of 1.88% and 1.57% respectively. CMJ1Mean force was the only variable with an overall TE < smallest worthwhile change (SWC).

Conclusion:

Selected variables obtained during CMJ1 and CMJ5 performance can be used to assess the impact of both acute and chronic training and competition. Variables derived from the CMJ5 may respond differently than their CMJ1 counterparts and should provide insights into differential mechanisms of response and adaptation.
Fluid Intake During Wheelchair Exercise in the Heat: Effects of Localized Cooling Garments
Authors: Goosey-Tolfrey Victoria L. , Diaper Nicholas J. , Crosland Jeanette , Tolfrey Keith
Published: August 2016

Background:

Wheelchair tennis players, competing in hot and humid environments, are faced with an increased risk of heat-related illness and impaired performance. This study examined the effects of head and neck cooling garments on perceptions of exertion (RPE), thermal sensation (TS), and water consumption during wheelchair exercise at 30.4 ± 0.6°C.

Methods:

Eight highly trained wheelchair tennis players (1 amputee and 7 spinal cord injured) completed two 60-min, intermittent sprint trials; once with cooling (COOL) and once without cooling (CON) in a balanced cross-over design. Players could drink water ad libitum at five predetermined intervals during each trial. Heart rate, blood lactate concentration, peak speed, TS, and RPE were recorded during the trials. Body mass and water consumption were measured before and after each trial.

Results:

Water consumption was lower in COOL compared with CON (700 ± 393 mL vs. 1198 ± 675 mL respectively;P= 0.042). Trends in data suggested lower RPE and TS under COOL conditions (N.S.). Total sweat losses ranged from 200 to 1300 mL; this equated to ~1% dehydration after water consumption had been accounted for when averaged across all trials. The ad libitum drinking volumes matched and, in some cases, were greater than the total sweat losses.

Conclusions:

These results suggest that there is a counterproductive effect of head and neck cooling garments on water consumption. However, despite consuming volumes of water at least equivalent to total sweat loss, changes in body mass suggest an incidence of mild dehydration during wheelchair tennis in the heat.
The Effect of Sequence of Skating-Specific Training on Skating Performance
Authors: Farlinger Chris M. , R. Fowles Jonathon
Published: August 2016

Purpose:

To determine the effectiveness of a progressively “skating specific” periodized off-season training program on skating performance in competitive hockey players.

Methods:

Twenty (M = 18; F = 2) highly skilled hockey players (age 15.9 ± 1.5 yr) completed 16 wk of standardized resistance and stability training supplemented with either off-ice simulated skating using the SkateSIM (SIM) or plyometric training (PLY) in a crossover design. Group 1 (PLY-SIM; N = 11) completed 8 wk of PLY followed by 8 wk of SIM. Group 2 (SIM-PLY; N = 9) completed 8 wk of SIM followed by 8 wk of PLY. Subjects completed on- and off-ice testing PRE, MID, and POST training.

Results:

Significant improvements in on-ice 35-m skating sprint (1.0%; P = .009) with significant improvements of 5% to 12% in various off-ice testing measures were observed PRE-MID in both groups. While few off-ice tests improved MID-POST, on-ice 35-m skating sprint times improved MID-POST by 2.3% (P = .000) with greater improvement in PLY-SIM (3.5%) versus SIM-PLY (0.8%; P < .002). Off-ice 30-m sprint (r = 0.56; P = .010) and Edgren side shuffle (r = –0.46; P < .040) were the only off-ice tests that significantly correlated to improvements in on-ice skating sprint performance.

Conclusion:

The initial gains PRE-MID and then the lack of improvement in many off-ice tests from the MID-POST supports the principle of diminishing returns in response to standardized resistance training. The improvement in on-ice skating sprint performance when supplemental training progressed in specificity supports the principle of specificity and promotes transfer to a complex sporting movement such as skating.
A Time-Motion Analysis of International Women’s Water Polo Match Play
Authors: D’Auria Shaun , Gabbett Tim
Published: August 2016

Purpose:

The purpose of this study was to investigate the physiological demands of field players in international women’s water polo match play.

Methods:

Video footage was collected at the 13th FINA Women’s Water Polo World Cup in Perth in 2002. Video recordings were analyzed using a simple hand-based notation system to record predefined activity durations, frequencies, and corresponding subjective intensities.

Results:

Average exercise bout duration was 7.4 ± 2.5 s and exercise to rest ratio within play 1:1.6 ± 0.6. The average pattern of exercise was represented by 64.0 ± 15.3% swimming, 13.1 ± 9.2% contested swimming, 14.0 ± 11.6% wrestling, and 8.9 ± 7.1% holding position. Significant differences existed between outside and center players for percentage time swimming (67.5 ± 14.0% vs 60.2 ± 13.3%, P = .002) and wrestling (9.9 ± 9.3% vs 18.4 ± 11.1%, P = .000). A significant difference was found in the number (P = .017) and duration (P = .010) of high-intensity activity (HIA) bouts performed each quarter for outside (1.8 ± 2.2 bouts, 7.0 ± 3.4 s) and center players (1.2 ± 1.5 bouts, 5.2 ± 3.4 s). Positional differences in HIA were the result of a significant difference (P = .000) in the number of maximal/near maximal swims (outside 1.2 ± 1.5 and center 0.5 ± 0.9 per quarter).

Conclusions:

This study characterizes international women’s water polo match play as a highly intermittent activity. Swimming, particularly high intensity, has greater significance to outside players, whereas wrestling has greater significance to center players.
An Analysis of the Pacing Strategies Adopted by Elite Athletes During Track Cycling
Authors: Corbett Jo
Published: August 2016

Purpose:

To investigate pacing strategy during the 1-km time trial (TT) and 3- and 4-km individual pursuit (IP), in elite cyclists.

Methods:

Total times and intermediate times were obtained from the 2007 and 2008 cycling World Championships in the 1-km TT and 2006, 2007, and 2008 World Championships in the 3- and 4-km IP. Data were analyzed to examine the pacing-profiles employed and pacing strategies of “slow” and “fast” performances.

Results:

Similar pacing-profiles were evident in each event, which were characterized by an initial acceleration followed by a progressive decay in split times. In the 1-km TT, the first 250-m split time was a primary determinant of total time, whereas the rate of fatigue over the remainder of the race did not discriminate between performances. The first 250-m split time was also related to total time in the 3- and 4-km IP, although to a lesser extent than in the 1-km TT, whereas the ability to maintain a consistent pacing-profile was of increased importance. There were differences in the pacing strategies of slow and fast performances in the 3- and 4-km IP, with slow performances characterized by an overly quick start with a concomitant slowing at the finish.

Conclusion:

The pacing profiles adopted were similar to the optimal pacing strategies proposed in simulation models of cycling performance. However, in the 3-km and 4-km IP small alterations in pacing strategy appear to be important, at the elite level.
The Effect of Sampling Time on Blood Lactate Concentration ([Bla]) in Trained Rowers
Authors: Kass Lindsy , Carpenter Roger
Published: August 2016

Purpose:

To compare blood lactate concentration ([Bla]) at 15 s and 45 s during the 1-min rest period between each stage of an incremental test in rowers and to establish the validity of using interchangeable sampling times.

Methods:

Seventeen male club rowers (mean ± SD, age 28.8 ± 5.7 years, height 186.9 ± 5.1 cm, body mass 85.4 ± 6.6 kg) performed an incremental rowing ergometer test, consisting of five stages of 4 min corresponding to approximately 80% HRmax. A 10-µL earlobe blood sample was collected from each subject at 15 s and again at 45 s in the final minute of each test stage and analyzed in duplicate. A maximum of 10 s was allowed for blood collection.

Results:

Statistical analysis using limits of agreement and correlation indicated a high level of agreement between the two [Bla] samples for all fve test stages (agreement >95%, confidence intervals [CI] = -0.5 to 1.5, r = .97, P < .05).

Conclusion:

These results suggest that a sampling time between 15 s and 45 s may be recommended for the valid assessment of the [Bla] threshold in rowing performance monitoring. This extends the current sampling time of 30 s used by physiologists and coaches for National and club-level Rowers.
Validity and Reliability of GPS Units to Monitor Cricket-Specific Movement Patterns
Authors: Petersen Carl , Pyne David , Portus Marc , Dawson Brian
Published: August 2016

Purpose:

The validity and reliability of three commercial global positioning system (GPS) units (MinimaxX, Catapult, Australia; SPI-10, SPI-Pro, GPSports, Australia) were quantified.

Methods:

Twenty trials of cricket-specific locomotion patterns and distances (walking 8800 m, jogging 2400 m, running 1200 m, striding 600 m, sprinting 20- to 40-m intervals, and run-a-three) were compared against criterion measures (400-m athletic track, electronic timing). Validity was quantified with the standard error of the estimate (SEE) and reliability estimated using typical error expressed as a coefficient of variation.

Results:

The validity (mean ± 90% confidence limits) for locomotion patterns walking to striding ranged from 0.4 ± 0.1 to 3.8 ± 1.4%, whereas for sprinting distances over 20 to 40 m including run-a-three (approx. 50 m) the SEE ranged from 2.6 ± 1.0 to 23.8 ± 8.8%. The reliability (expressed as mean [90% confidence limits]) of estimating distance traveled by walking to striding ranged from 0.3 (0.2 to 0.4) to 2.9% (2.3 to 4.0). Similarly, mean reliability of estimating different sprinting distances over 20 to 40 m ranged from 2.0 (1.6 to 2.8) to 30.0% (23.2 to 43.3).

Conclusions:

The accuracy and bias was dependent on the GPS brand employed. Commercially available GPS units have acceptable validity and reliability for estimating longer distances (600–8800 m) in walking to striding, but require further development for shorter cricket-specifc sprinting distances.
The Effect of Competition on Salivary Testosterone in Elite Female Athletes
Authors: Hamilton Lisa Dawn , van Anders Sari M. , Cox David N. , Watson Neil V.
Published: August 2016

The association between androgens and competition in women has been understudied compared with men. The current study examined the link between testosterone (T) and competition in elite female athletes, using a sample of female wrestlers that included athletes competing at both the national and international level. In a repeated-measures design, saliva samples were collected before and after wrestling bouts, with comparable samples of wins and losses, and subsequently analyzed for T. Study results showed a 22% increase in circulating bioavailable T from pre-to postbout, F(1, 12) = 9.71, P = .009. There was no significant difference in T between win or loss outcomes. These findings—showing a link between individual head-to-head competition and T in women—demonstrate that women’s androgenic responses to environmental contexts are dynamic and may be an important factor to address in research on competitive performance.