bluuebunny/crossref_metadata_2025_split huggingface dataset:
Induced Alkalosis and Caffeine Supplementation: Effects on 2,000-m Rowing Performance
Authors: Carr Amelia J. , Gore Christopher J. , Dawson Brian 
Published: August 2016

Introduction:The purpose of this investigation was to determine the effect of ingested caffeine, sodium bicarbonate, and their combination on 2,000-m rowing performance, as well as on induced alkalosis (blood and urine pH and blood bicarbonate concentration [HCO3−]), blood lactate concentration ([La−]), gastrointestinal symptoms, and rating of perceived exertion (RPE).Methods:In a double-blind, crossover study, 8 well-trained rowers performed 2 baseline tests and 4 × 2,000-m rowing-ergometer tests after ingesting 6 mg/kg caffeine, 0.3 g/kg body mass (BM) sodium bicarbonate, both supplements combined, or a placebo. Capillary blood samples were collected at preingestion, pretest, and posttest time points. Pairwise comparisons were made between protocols, and differences were interpreted in relation to the likelihood of exceeding the smallestworthwhile- change thresholds for each variable. A likelihood of >75% was considered a substantial change.Results:Caffeine supplementation elicited a substantial improvement in 2,000-m mean power, with mean (± SD) values of 354 ± 67 W vs. placebo with 346 ± 61 W. Pretest [HCO3−] reached 29.2 ± 2.9 mmol/L with caffeine + bicarbonate and 29.1 ± 1.9 mmol/L with bicarbonate. There were substantial increases in pretest [HCO3−] and pH and posttest urine pH after bicarbonate and caffeine + bicarbonate supplementation compared with placebo, but unclear performance effects.Conclusions:Rowers’ performance in 2,000-m efforts can improve by ~2% with 6 mg/kg BM caffeine supplementation. When caffeine is combined with sodium bicarbonate, gastrointestinal symptoms may prevent performance enhancement, so further investigation of ingestion protocols that minimize side effects is required.
Nutrition Status of Junior Elite Canadian Female Soccer Athletes
Authors: Gibson Jennifer C. , Stuart-Hill Lynneth , Martin Steven , Gaul Catherine 
Published: August 2016

Context:Adolescent female team-sport athletes are faced with the challenge of meeting nutrition requirements for growth and development, as well as sport performance. There is a paucity of evidence describing the dietary adequacy of this population in respect to these physiological demands. Therefore, the aim of this study was to comprehensively evaluate the nutrition status of junior elite female soccer athletes.Method:A total of 33 athletes (15.7 ± 0.7 yr) completed anthropometric assessment, 4-day food records analyzed for macro- and micronutrient intake, and hematological analysis. Energy expenditure was estimated using predictive equations.Results:Mean sum of 7 skinfolds was 103.1 ± 35.2 mm, and body-mass index was 22.7 ± 2.7. Mean energy intake was 2,079 ± 460 kcal/day, and estimated energy expenditure was 2,546 ± 190 kcal/day. Of the athletes, 51.5% consumed <5g/kg carbohydrate, 27.3% consumed <1.2g/kg protein, and 21.2% consumed <25% of energy intake from fat. A large proportion of athletes did not meet Dietary Reference Intakes for pantothenic acid (54.5%), vitamin D (100%), folate (69.7%), vitamin E (100%), and calcium (66.7%). Compared with recommendations for athletes, 89.3% and 50.0% of participants had depleted iron and 25-hydroxyvitamin D, respectively.Conclusion:A high proportion of players were not in energy balance, failed to meet carbohydrate and micronutrient recommendations, and presented with depleted iron and vitamin D status. Suboptimal nutrition status may affect soccer performance and physiological growth and development. More research is needed to understand the unique nutrition needs of this population and inform sport nutrition practice and research.
Restoration of Menses With Nonpharmacologic Therapy in College Athletes With Menstrual Disturbances: A 5-Year Retrospective Study
Authors: Arends Julie C. , Cheung Min-Yuen C. , Barrack Michelle T. , Nattiv Aurelia 
Published: August 2016

Background:Functional hypothalamic amenorrhea is common among female athletes and may be difficult to treat. Restoration of menses (ROM) is crucial to prevent deleterious effects to skeletal and reproductive health.Objectives:To determine the natural history of menstrual disturbances in female college athletes managed with nonpharmacologic therapies including increased dietary intake and/or decreased exercise expenditure and to identify factors associated with ROM.Study Design:A 5-yr retrospective study of college athletes at a major Division I university.Methods:373 female athletes’ charts were reviewed. For athletes with menstrual disturbances, morphometric variables were noted. Months to ROM were recorded for each athlete.Results:Fifty-one female athletes (19.7%) had menstrual disturbances (14.7% oligomenorrheic, 5.0% amenorrheic). In all, 17.6% of oligo-/amenorrheic athletes experienced ROM with nonpharmacologic therapy. Mean time to ROM among all athletes with menstrual disturbances was 15.6 ± 2.6 mo. Total absolute (5.3 ± 1.1 kg vs. 1.3 ± 1.1 kg, p < .05) and percentage (9.3% ± 1.9% vs. 2.3% ± 1.9%, p < .05) weight gain and increase in body-mass index (BMI; 1.9 ± 0.4 kg/m2 vs. 0.5 ± 0.4 kg/m2, p < .05) emerged as the primary differentiating characteristics between athletes with ROM and those without ROM. Percent weight gain was identified as a significant positive predictor of ROM, OR (95% CI) = 1.25 (1.01, 1.56), p < .05.Conclusions:Nonpharmacologic intervention in college athletes with menstrual disturbances can restore regular menstrual cycles, although ROM may take more than 1 yr. Weight gain or an increase in BMI may be important predictors of ROM.
Effects of Caffeine, Sodium Bicarbonate, and Their Combined Ingestion on High-Intensity Cycling Performance
Authors: Kilding Andrew E. , Overton Claire , Gleave Jonathan 
Published: August 2016

Purpose:To determine the effects of ingesting caffeine (CAFF) and sodium bicarbonate (SB), taken individually and simultaneously, on 3-km cycling time-trial (TT) performance.Method:Ten well-trained cyclists, age 24.2 ± 5.4 yr, participated in this acute-treatment, double-blind, crossover study that involved four 3-km cycling TTs performed on separate days. Before each TT, participants ingested either 3 mg/kg body mass (BM) of CAFF, 0.3 g · kg−1 · BM−1 of SB, a combination of the two (CAFF+SB), or a placebo (PLAC). They completed each 3-km TT on a laboratory-based cycle ergometer, during which physiological, perceptual, and performance measurements were determined. For statistical analysis, the minimal worthwhile difference was considered ~1% based on previous research.Results:Pretrial pH and HCO3 were higher in SB and CAFF+SB than in the CAFF and PLAC trials. Differences across treatments for perceived exertion and gastric discomfort were mostly unclear. Compared with PLAC, mean power output during the 3-km TT was higher in CAFF, SB, and CAFF+SB trials (2.4%, 2.6%, 2.7% respectively), resulting in faster performance times (–0.9, –1.2, –1.2% respectively). Effect sizes for all trials were small (0.21–0.24).Conclusions:When ingested individually, both CAFF and SB enhance high-intensity cycling TT performance in trained cyclists. However, the ergogenic effect of these 2 popular supplements was not additive, bringing into question the efficacy of coingesting the 2 supplements before short-duration high-intensity exercise. In this study there were no negative effects of combining CAFF and SB, 2 relatively inexpensive and safe supplements.
Influence of Beverage Temperature on Palatability and Fluid Ingestion During Endurance Exercise: A Systematic Review
Authors: Burdon Catriona A. , Johnson Nathan A. , Chapman Phillip G. , O’Connor Helen T. 
Published: August 2016

Beverage palatability is known to influence fluid consumption during exercise and may positively influence hydration status and help prevent fatigue, heat illness, and decreased performance.Purpose:The aims of this review were to evaluate the effect of beverage temperature on fluid intake during exercise and investigate the influence of beverage temperature on palatability.Methods:Citations from multiple databases were searched from the earliest record to November 2010 using the terms beverage, fluid, or water and palatability, preference, feeding, and drinking behavior and temperature. Included studies (N = 14) needed to use adult (≥18 yr) human participants, have beverage temperatures ≤50 °C, and measure consumption during exercise and/or palatability.Results:All studies reporting palatability (n = 10) indicated that cold (0–10 °C) or cool (10–22 °C) beverages were preferred to warmer ones (control, ≥22 °C). A meta-analysis on studies reporting fluid consumption (n = 5) revealed that participants consumed ~50% (effect size = 1.4, 0.75–2.04, 95% CI) more cold/cool beverages than control during exercise. Subanalysis of studies assessing hydration status (n = 4) with consumption of cool/cold vs. warm beverages demonstrated that dehydration during exercise was reduced by 1.3% of body weight (1.6–0.9%, 95% CI; p < .001).Conclusion:Cool beverage temperatures (<22 °C) significantly increased fluid palatability, fluid consumption, and hydration during exercise vs. control (≥22 °C).
Weight and Body-Composition Change during the College Freshman Year in Male General-Population Students and Army Reserve Officer Training Corps (ROTC) Cadets
Authors: Crombie Aaron P. , Liu Pei-Yang , Ormsbee Michael J. , Ilich Jasminka Z. 
Published: August 2016

Purpose:To examine relationships between changes in body weight, body composition, and fitness level in male students of the general population and those in the Army Reserve Officer Training Corps (ROTC) program during the freshman year of college.Methods:Thirty-seven (18.4 ± 0.7 yr) healthy, nonsmoking, first-semesterresident male students were divided into 3 groups: low active (LA), high active (HA), and ROTC. Baseline (beginning of freshman year) and 6-month follow-up measurements included anthropometry, body composition (by DXA), 3-day food records, and physical activity (PA) assessment.Results:Weight and body-mass index did not change significantly within or among groups. HA participants compared with LA and ROTC had a significant decrease in body fat (–1.6% ± 2.5% vs. 1.9% ± 1.2% and 0.8% ± 2.2%, respectively). They also had a significant increase in lean mass compared with LA and ROTC (1.8 ± 1.1 kg vs. –0.2 ± 2.0 kg and 0.2 ± 1.7 kg, respectively). All p values were <.05. ROTC and LA participants were similar in all measures of body composition and PA and had significantly lower PA levels than the HA group. No significant relationships were observed between dietary variables and body-composition changes.Conclusions:These results suggest that higher PA was the most powerful determinant in achieving favorable body-composition outcomes. In addition, current physical training conducted by ROTC at Florida State University (which seems to be a practice nationwide) might not be sufficient to offset gains in body fat.
Blood Oxidative-Stress Markers During a High-Altitude Trek
Authors: Miller Lindsey E. , McGinnis Graham R. , Kliszczewicz Brian , Slivka Dustin , Hailes Walter , Cuddy John , Dumke Charles , Ruby Brent , Quindry John C. 
Published: August 2016

Oxidative stress occurs as a result of altitude-induced hypobaric hypoxia and physical exercise. The effect of exercise on oxidative stress under hypobaric hypoxia is not well understood.Purpose:To determine the effect of high-altitude exercise on blood oxidative stress. Nine male participants completed a 2-d trek up and down Mt Rainer, in North America, at a peak altitude of 4,393 m. Day 1 consisted of steady-pace climbing for 6.25 hr to a final elevation of 3,000 m. The 4,393-m summit was reached on Day 2 in approximately 5 hr. Climb–rest intervals varied but were consistent between participants, with approximately 14 hr of total time including rest periods. Blood samples were assayed for biomarkers of oxidative stress and antioxidant potential at the following time points: Pre (before the trek), 3Kup (at ascent to 3,000 m), 3Kdown (at 3,000 m on the descent), and Post (posttrek at base elevation). Blood serum variables included ferric-reducing antioxidant potential (FRAP), Trolox equivalent antioxidant capacity (TEAC), protein carbonyls (PC), and lipid hydroperoxides. Serum FRAP was elevated at 3Kup and 3Kdown compared with Pre and Post values (p = .004, 8% and 11% increase from Pre). Serum TEAC values were increased at 3Kdown and Post (p = .032, 10% and 18% increase from Pre). Serum PC were elevated at 3Kup and 3Kdown time points (p = .034, 194% and 138% increase from Pre), while lipid hydroperoxides were elevated Post only (p = .004, 257% increase from Pre).Conclusions:Findings indicate that high-altitude trekking is associated with increased blood oxidative stress.
Reverse Effects of DPI Administration Combined With Glutamine Supplementation on Function of Rat Neutrophils Induced by Overtraining
Authors: Dong Jingmei , Chen Peijie , Liu Qing , Wang Ru , Xiao Weihua , Zhang Yajun 
Published: August 2016

Purpose:To examine the excessive reactive oxygen species (ROS) mediated by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and the combined effect of glutamine supplementation and diphenyleneiodonium (DPI) on the function of neutrophils induced by overtraining.Methods:Fifty male Wistar rats were randomly divided into 5 groups: control group (C), overtraining group (E), DPI-administration group (D), glutamine-supplementation group (G), and combined DPI and glutamine group (DG). Blood was sampled from the orbital vein after rats were trained on treadmill for 11 wk. Cytokine and lipid peroxidation in blood plasma were measured by enzyme-linked immunosorbent assay. The colocalization between gp91phox and p47phox of the NADPH oxidase was detected using immunocytochemistry and confocal microscopy. The activity of NADPH oxidase was assessed by chemiluminescence. Neutrophils’ respiratory burst and phagocytosis function were measured by flow cytometry.Results:NADPH oxidase was activated by overtraining. Cytokine and lipid peroxidation in blood plasma and the activity of NADPH oxidase were markedly increased in Group E compared with Group C. Neutrophil function was lower in Group E than Group C. Both lower neutrophils function and higher ROS production were reversed in Group DG. The glutamine and DPI interference alone in Group D and Group G was less effective than DPI and glutamine combined in group DG.Conclusion:Activation of NADPH oxidase is responsible for the production of superoxide anions, which leads to excessive ROS and is related to the decrease in neutrophil function induced by overtraining. The combined DPI administration and glutamine supplementation reversed the decreased neutrophil function after overtraining.
Ad Libitum Fluid Intake Does Not Prevent Dehydration in Suboptimally Hydrated Young Soccer Players During a Training Session of a Summer Camp
Authors: Arnaoutis Giannis , Kavouras Stavros A. , Kotsis Yiannis P. , Tsekouras Yiannis E. , Makrillos Michalis , Bardis Costas N. 
Published: August 2016

There is a lack of studies concerning hydration status of young athletes exercising in the heat.Purpose:To assess preexercise hydration status in young soccer players during a summer sports camp and to evaluate bodywater balance after soccer training sessions.Methods:Initial hydration status was assessed in 107 young male soccer players (age 11–16 yr) during the 2nd day of the camp. Seventy-two athletes agreed to be monitored during 2 more training sessions (3rd and 5th days of the camp) to calculate dehydration via changes in body weight, while water drinking was allowed ad libitum. Hydration status was assessed via urine specific gravity (USG), urine color, and changes in total body weight. Mean environmental temperature and humidity were 27.2 ± 2 °C and 57% ± 9%, respectively.Results:According to USG values, 95 of 107 of the players were hypohydrated (USG ≥ 1.020) before practice. The prevalence of dehydration observed was maintained on both days, with 95.8% and 97.2% of the players being dehydrated after the training sessions on the 3rd and 5th days, respectively. Despite fluid availability, 54 of the 66 (81.8%) dehydrated players reduced their body weight (–0.35 ± 0.04 kg) as a response to training, while 74.6% (47 out of the 63) further reduced their body weight (–0.22 ± 0.03 kg) after training on the 5th day.Conclusion:Approximately 90% of the young soccer players who began exercising under warm weather conditions were hypohydrated, while drinking ad libitum during practice did not prevent further dehydration in already dehydrated players.
Oral Creatine Supplementation’s Decrease of Blood Lactate During Exhaustive, Incremental Cycling
Authors: Oliver Jonathan M. , Joubert Dustin P. , Martin Steven E. , Crouse Stephen F. 
Published: August 2016

Purpose:To determine the effects of creatine supplementation on blood lactate during incremental cycling exercise.Methods:Thirteen male subjects (M ± SD 23 ± 2 yr, 178.0 ± 8.1 cm, 86.3 ± 16.0 kg, 24% ± 9% body fat) performed a maximal, incremental cycling test to exhaustion before (Pre) and after (Post) 6 d of creatine supplementation (4 doses/d of 5 g creatine + 15 g glucose). Blood lactate was measured at the end of each exercise stage during the protocol, and the lactate threshold was determined as the stage before achieving 4 mmol/L. Lactate concentrations during the incremental test were analyzed using a 2 (condition) × 6 (exercise stage) repeated-measures ANOVA. Differences in power at lactate threshold, power at exhaustion, and total exercise time were determined by paired t tests and are presented as M ± SD.Results:Lactate concentrations were reduced during exercise after supplementation, demonstrating a significant condition effect (p = .041). There was a tendency for increased power at the lactate threshold (Pre 128 ± 45 W, Post 143 ± 26 W; p = .11). Total time to fatigue approached significant increases (Pre 22.6 ± 3.2 min, Post 23.3 ± 3.3 min; p = .056), as did maximal power output (Pre 212.5 ± 32.5 W, Post 220 ± 34.6 W; p = .082).Conclusions:Our findings demonstrate that creatine supplementation decreases lactate during incremental cycling exercise and tends to raise lactate threshold. Therefore, creatine supplementation could potentially benefit endurance athletes.
Influence of Female Sports Dietitians’ Physical Characteristics on Athlete Perception of Effectiveness
Authors: Lovell Geoff P. , Parker John K. , Slater Gary J. 
Published: August 2016

Research in sports-science disciplines such as sport psychology has demonstrated that practitioners’ physical characteristics influence clients’ perceptions of their effectiveness, potentially mediating the efficacy of subsequent interventions. However, very little research has been directed toward this issue for sports dietitians (SDs), the health professionals whom athletes are likely to engage to assist with manipulation of traits of physique. Therefore, the purpose of this investigation was to determine whether SDs’ phenotype, specifically body-mass index (BMI), and type of dress influence potential clients’ preference to consult them for dietetic support and if this affects their perceived effectiveness.Methods:One hundred volunteers (mean age 18.7 ± 0 .8 years) all participating in regular competitive sport, classified by gender (male, n = 55, or female, n = 45) and competitive standard (elite/subelite, n = 68, or club/recreational, n = 32) viewed slides representing four concurrently presented computer-generated images of the same female SD manipulated to represent different BMIs and dress types. Participants were asked to rank the SDs in order of their preference to work with them and, second, to rate their perceived effectiveness of each of the SDs.Results:Key findings included the observation of a significant BMI main effect F(6, 91) = 387.39, p < .001 (effect size .96), with participants’ ranking of preference and rating of perceived effectiveness of female SDs decreasing with increasing BMI.Conclusion:SDs should consider their physical appearance when meeting with athletes, as this may affect their perceived efficacy.
Beer as a Sports Drink? Manipulating Beer’s Ingredients to Replace Lost Fluid
Authors: Desbrow Ben , Murray Daniel , Leveritt Michael 
Published: August 2016

Purpose:To investigate the effect of manipulating the alcohol and sodium content of beer on fluid restoration following exercise.Method:Seven male volunteers exercised on a cycle ergometer until 1.96 ± 0.25% body mass (mean± SD) was lost. Participants were then randomly allocated a different beer to consume on four separate occasions. Drinks included a low-alcohol beer (2.3% ABV; LightBeer), a low-alcohol beer with 25 mmol×L−1 of added sodium (LightBeer+25), a full-strength beer (4.8% ABV; Beer), or a full-strength beer with 25 mmol×L−1 of added sodium (Beer+25). Volumes consumed were equivalent to 150% of body mass loss during exercise and were consumed over a 1h period. Body mass and urine samples were obtained before and hourly for 4 hr after beverage consumption.Results:Significantly enhanced net fluid balance was achieved following the LightBeer+25 trial (–1.02 ± 0.35 kg) compared with the Beer (–1.59 ± 0.32 kg) and Beer+25 (–1.64 ± 0.28 kg) treatments. Accumulated urine output was significantly lower in the LightBeer+25 trial (1477 ± 485 ml) compared with the Beer+25 (2101 ± 482 ml) and Beer (2175 ± 372 ml) trials.Conclusion:A low alcohol beer with added sodium offers a potential compromise between a beverage with high social acceptance and one which avoids the exacerbated fluid losses observed when consuming full strength beer.
Monitoring Changes in Lean Mass of Elite Male and Female Swimmers
Authors: Pyne David B. , Anderson Megan E. , Hopkins Will G. 
Published: August 2016

Purpose:To characterize within-subject changes in anthropometric characteristics of elite swimmers within and between seasons.Methods:The subjects were 77 elite swimmers (31 females, 46 males, age 15 to 30 years) monitored over 0.4 to 9.2 years. One anthropometrist recorded their body mass (M) and sum of 7 skin-fold thicknesses (S) on 2042 occasions over 14 years from phase to phase within a season and over consecutive seasons. We estimated change in lean mass using a newly derived index (LMI) that tracked changes in M controlled for changes in S.Results:The LMI is M/Sx, where x = 0.16 ± 0.04 for females and 0.15 ± 0.05 for males (mean ± SD). The LMI of males increased 1.1% (95% confidence limits ± 0.2%) between preseason and taper phases, almost twice as much as that of females (0.6% ± 0.3%). During the same period, M and S fell by ~1% and ~11%, respectively. From season to season LMI increased by 0.9% (0.8% to 1.0%) for males and 0.5% (0.3% to 0.7%) for females. All these within-subject effects on LMI were well defined (±~0.3%). The typical variation (SD) of an individual’s LMI was 1.2% for assessments within a season and 1.9% between seasons, with a short-term technical error of measurement of ~0.5%.Conclusion:Coaches and conditioners should typically expect a twofold greater increase in lean mass in male swimmers within and between seasons than in females. An LMI of the form M/Sx should be useful for monitoring individual swimmers and athletes in other sports in which body composition affects performance.