bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Bovine Colostrum Supplementation on Salivary IgA in Distance Runners
Authors: Crooks Christine V. , Wall Clare R. , Cross Martin L. , Rutherfurd-Markwick Kay J.
Published: August 2016

Secretory IgA in saliva (s-IgA) is a potential mucosal immune correlate of upper respiratory tract infection (URTI) status. Nutritional supplements may improve mucosal immunity, and could be beneficial to athletes who are at increased risk of URTI. In this study, 35 distance runners (15 female, 20 male, age 35 to 58 y) consumed a supplement of either bovine colostrum or placebo for 12 wk. Saliva samples were taken prior to training at baseline, monthly during supplementation, and 2 wk post supplementation. Median levels of s-IgA increased by 79% in the colostrum group after 12 wk intervention, and the time-dependent change from baseline value was significant (P = 0.0291). This significance was still apparent after adjusting for training volume and self-reporting of upper respiratory symptoms. This study has demonstrated increased s-IgA levels among a cohort of athletes following colostrum supplementation. While this result is statistically significant, its physiological interpretation must be viewed with caution due to the small numbers in this study and the large variability in s-IgA levels.
Disordered Eating and Menstrual Irregularity in High School Athletes in Lean-Build and Nonlean-Build Sports
Authors: Nichols Jeanne F. , Rauh Mitchell J. , Barrack Michelle T. , Barkai Hava-Shoshana , Pernick Yael
Published: August 2016

The authors’ purpose was to determine the prevalence and compare associations of disordered eating (DE) and menstrual irregularity (MI) among high school athletes. The Eating Disorder Examination Questionnaire (EDE-Q) and a menstrual-history questionnaire were administered to 423 athletes (15.7 ± 1.2 y, 61.2 ± 10.2 kg) categorized as lean build (LB; n = 146) or nonlean build (NLB; n = 277). Among all athletes, 20.0% met the criteria for DE and 20.1% for MI. Although the prevalence of MI was higher in LB (26.7%) than NLB (16.6%) athletes (P = 0.01), no differences were found for DE. For both sport types, oligo/amenorrheic athletes consistently reported higher EDE-Q scores than eumenorrheic athletes (P < 0.05). Athletes with DE were over 2 times as likely (OR = 2.3, 95%CI: 1.3, 4.2) to report oligo/amenorrhea than athletes without DE. These data establish an association between DE and MI among high school athletes and indicate that LB athletes have more MI but not DE than NLB athletes.
Carbohydrate-Supplement Form and Exercise Performance
Authors: Campbell Caitlin , Prince Diana , Braun Marlia , Applegate Elizabeth , Casazza Gretchen A.
Published: August 2016

Numerous studies have shown that ingesting carbohydrate in the form of a drink can improve exercise performance by maintaining blood glucose levels and sparing endogenous glycogen stores. The effectiveness of carbohydrate gels or jellybeans in improving endurance performance has not been examined. On 4 separate days and 1–2 hr after a standardized meal, 16 male (8; 35.8 ± 2.5 yr) and female (8; 32.4 ± 2.4 yr) athletes cycled at 75% VO2peak for 80 min followed by a 10-km time trial. Participants consumed isocaloric (0.6 g of carbohydrate per kg per hour) amounts of randomly assigned sports beans, sports drink, gel, or water only, before, during, and after exercise. Blood glucose concentrations were similar at rest between treatments and decreased significantly during exercise with the water trial only. Blood glucose concentrations for all carbohydrate supplements were significantly, p < .05, higher than water during the 80-min exercise bout and during the time trial (5.7 ± 0.2 mmol/L for sports beans, 5.6 ± 0.2 mmol/L for sports drink, 5.7 ± 0.3 mmol/L for gel, and 4.6 ± 0.3 mmol/L for water). There were no significant differences in blood glucose between carbohydrate treatments. The 10-km time trials using all 3 carbohydrate treatments were significantly faster (17.2 ± 0.6 min for sports beans, 17.3 ± 0.6 min for sports drink, and 17.3 ± 0.6 min for gel) than water (17.8 ± 0.7 min). All carbohydrate-supplement types were equally effective in maintaining blood glucose levels during exercise and improving exercise performance compared with water only.
Heart-Rate Response to Sympathetic Nervous Stimulation, Exercise, and Magnesium Concentration in Various Sleep Conditions
Authors: Omiya Kazuto , Akashi Yoshihiro J , Yoneyama Kihei , Osada Naohiko , Tanabe Kazuhiko , Miyake Fumihiko
Published: August 2016

The aim of this study was to clarify the mechanism of impaired exercise tolerance in chronic sleep-restricted conditions by investigating variables related to heart-rate (HR) response to sympathetic nervous stimulation. Sixteen healthy men (mean age 21.5 years) were tested in a control state, acute sleep-loss state, and chronic sleeprestricted state. Participants underwent cardiopulmonary exercise testing in each state. Their norepinephrine (NE) concentration was measured before and immediately after exercise. Intracellular magnesium (Mg) concentration was measured in a resting state. Exercise duration was shorter and the ratio of HR response to the percentage increase in NE was higher in the chronic sleep-restricted state than in the control state. Intracellular Mg gradually decreased from control to chronic sleep restriction. There was a negative correlation between peak exercise duration and the ratios of HR response to the rate of increase in NE. Intracellular Mg was positively correlated with the ratios of HR response to the increase in NE both in control and in acute sleep loss. The authors conclude that the impaired exercise tolerance in a chronic sleep-restricted state is caused by hypersensitivity of the HR response to sympathetic nervous stimulation, which showed a compensation for decreased intracellular Mg concentration.
The Influence of Supplementation with Rhodiola rosea L. Extract on Selected Redox Parameters in Professional Rowers
Authors: Skarpanska-Stejnborn Anna , Pilaczynska-Szczesniak Lucja , Basta Piotr , Deskur-Smielecka Ewa
Published: August 2016

The aim of this study was to investigate the effect of Rhodiola rosea supplementation on the balance of oxidants and antioxidants in the serum and erythrocytes of competitive rowers. This double-blinded study included 22 members of the Polish Rowing Team who were participating in a preparatory camp. Participants were randomly assigned to the supplemented group (n = 11), who received 100 mg of R. rosea extract twice daily for 4 wk, or the placebo group (n = 11). At the beginning and end of the study, participants performed a 2,000-m maximum test on a rowing ergometer. Blood samples were taken from the antecubital vein before each exercise test, 1 min after completing the test, and after a 24-hr restitution period. The following redox parameters were assessed in erythrocytes: superoxide dismutase activity, glutathione peroxidase activity, and thiobarbituric-acid-reactive substances concentrations. In addition, creatine kinase activity and total antioxidant capacity were measured in plasma samples, lactate levels were determined in capillary blood samples, and uric acid concentrations were measured in serum. After supplementation, the total plasma antioxidant capacity was significantly higher (p = .0002) in the supplemented group than in the placebo group, and superoxide dismutase activity in erythrocytes directly after and 24 hr after the ergometry was significantly (p = .0461) lower in athletes receiving R. rosea extracts than in the placebo group. In conclusion, supplementation with R. rosea increased antioxidant levels in the plasma of professional rowers but had no effect on oxidative damage induced by exhaustive exercise.
Carbohydrate Mouth Rinsing in the Fed State: Lack of Enhancement of Time-Trial Performance
Authors: Beelen Milou , Berghuis Jort , Bonaparte Ben , Ballak Sam B. , Jeukendrup Asker E. , van Loon Luc J.C
Published: August 2016

It has been reported previously that mouth rinsing with a carbohydrate-containing solution can improve cycling performance. The purpose of the current study was to investigate the impact of such a carbohydrate mouth rinse on exercise performance during a simulated time trial in a more practical, postprandial setting. Fourteen male endurance-trained athletes were selected to perform 2 exercise tests in the morning after consuming a standardized breakfast. They performed an ~1-hr time trial on a cycle ergometer while rinsing their mouths with either a 6.4% maltodextrin solution (CHO) or water (PLA) after every 12.5% of the set amount of work. Borg’s rating of perceived exertion (RPE) was assessed after every 25% of the set amount of work, and power output and heart rate were recorded continuously throughout the test. Performance time did not differ between treatments and averaged 68.14 ± 1.14 and 67.52 ± 1.00 min in CHO and PLA, respectively (p = .57). In accordance, average power output (265 ± 5 vs. 266 ± 5 W, p = .58), heart rate (169 ± 2 vs. 168 ± 2 beats/min, p = .43), and RPE (16.4 ± 0.3 vs. 16.7 ± 0.3 W, p = .26) did not differ between treatments. Furthermore, after dividing the trial into 8s, no differences in power output, heart rate, or perceived exertion were observed over time between treatments. Carbohydrate mouth rinsing does not improve time-trial performance when exercise is performed in a practical, postprandial setting.
Effect of Two Different Weight-Loss Rates on Body Composition and Strength and Power-Related Performance in Elite Athletes
Authors: Garthe Ina , Raastad Truls , Refsnes Per Egil , Koivisto Anu , Sundgot-Borgen Jorunn
Published: August 2016

When weight loss (WL) is necessary, athletes are advised to accomplish it gradually, at a rate of 0.5–1 kg/wk. However, it is possible that losing 0.5 kg/wk is better than 1 kg/wk in terms of preserving lean body mass (LBM) and performance. The aim of this study was to compare changes in body composition, strength, and power during a weekly body-weight (BW) loss of 0.7% slow reduction (SR) vs. 1.4% fast reduction (FR). We hypothesized that the faster WL regimen would result in more detrimental effects on both LBM and strength-related performance. Twenty-four athletes were randomized to SR (n = 13, 24 ± 3 yr, 71.9 ± 12.7 kg) or FR (n = 11, 22 ± 5 yr, 74.8 ± 11.7 kg). They followed energy-restricted diets promoting the predetermined weekly WL. All athletes included 4 resistance-training sessions/wk in their usual training regimen. The mean times spent in intervention for SR and FR were 8.5 ± 2.2 and 5.3 ± 0.9 wk, respectively (p < .001). BW, body composition (DEXA), 1-repetition-maximum (1RM) tests, 40-m sprint, and countermovement jump were measured before and after intervention. Energy intake was reduced by 19% ± 2% and 30% ± 4% in SR and FR, respectively (p = .003). BW and fat mass decreased in both SR and FR by 5.6% ± 0.8% and 5.5% ± 0.7% (0.7% ± 0.8% vs. 1.0% ± 0.4%/wk) and 31% ± 3% and 21 ± 4%, respectively. LBM increased in SR by 2.1% ± 0.4% (p < .001), whereas it was unchanged in FR (–0.2% ± 0.7%), with significant differences between groups (p < .01). In conclusion, data from this study suggest that athletes who want to gain LBM and increase 1RM strength during a WL period combined with strength training should aim for a weekly BW loss of 0.7%.
Effects of Lactate Consumption on Blood Bicarbonate Levels and Performance During High-Intensity Exercise
Authors: Morris David M. , Shafer Rebecca S. , Fairbrother Kimberly R. , Woodall Mark W.
Published: August 2016

The authors sought to determine the effects of oral lactate consumption on blood bicarbonate (HCO3−) levels, pH levels, and performance during high-intensity exercise on a cycle ergometer. Subjects (N = 11) were trained male and female cyclists. Time to exhaustion (TTE) and total work were measured during high-intensity exercise bouts 80 min after the consumption of 120 mg/kg body mass of lactate (L), an equal volume of placebo (PL), or no treatment (NT). Blood HCO3− increased significantly after ingestion of lactate (p < .05) but was not affected in PL or NT (p > .05). No changes in pH were observed as a result of treatment. TTE and total work during the performance test increased significantly by 17% in L compared with PL and NT (p = .02). No significant differences in TTE and total work were seen between the PL and NT protocols (p = .85). The authors conclude that consuming 120 mg/kg body mass of lactate increases HCO3− levels and increases exercise performance during high-intensity cycling ergometry to exhaustion.
The Body Composition, Nutritional Knowledge, Attitudes, Behaviors, and Future Education Needs of Senior Schoolboy Rugby Players in Ireland
Authors: Walsh Michelle , Cartwright Laura , Corish Clare , Sugrue Sheila , Wood-Martin Ruth
Published: August 2016

Purpose:

This study examined the body composition, nutritional knowledge, behaviors, attitudes, and educational needs of senior schoolboy rugby players in Ireland.

Methods:

Participants included 203 male rugby players age 15–18 yr competing at Senior School’s Cup level in Leinster, Ireland. Estimation of body composition included measurement of height, weight, and percentage body fat (PBF; using bioelectrical impedance analysis, Tanita BC-418). Nutritional knowledge, behaviors, attitudes, and education needs were assessed by questionnaire.

Results:

The range of PBF was 5.1–25.3%. Sixty-eight percent of the players in this study had a healthy PBF (10–20%), 32 (22%) were classified as underweight (<10% body fat), and 9.7% (n = 14) were overweight. Assessment of nutritional knowledge demonstrated poor knowledge of the foods required for refueling, appropriate use of sports drinks, and the role of protein in muscle formation. Alcohol consumption and dietary supplement use were reported by 87.7% and 64.5%, respectively. A perception that greater body size enhances sport performance did not predict dietary supplement use. Nutritional advice had been previously sought by 121 players from coaches (66.9%), magazines (42.1%), Web sites (38.8%), peers (35.5%), family (28.1%), sport organizations (16.5%), and health professionals (8.2%). Nutritional knowledge was no better in these players, nor did better nutritional knowledge correlate with positive dietary behaviors or attitudes.

Conclusions:

Most players had a healthy PBF. Despite a positive attitude toward nutrition, poor nutritional knowledge and dietary practices were observed in many players. Young athletes’ nutritional knowledge and dietary practices may benefit from appropriate nutritional education.
Risk of Nutrient Inadequacies in Elite Canadian Athletes With Spinal Cord Injury
Authors: Krempien Jennifer L. , Barr Susan I.
Published: August 2016

Energy intakes of adults with spinal cord injury (SCI) have been reported to be relatively low, with many micronutrients below recommended amounts, but little is known about the diets of athletes with SCI. The purpose of this cross-sectional, observational study was to assess energy intakes and estimate the prevalence of dietary inadequacy in a sample of elite Canadian athletes with SCI (n = 32). Three-day self-reported food diaries completed at home and training camp were analyzed for energy (kcal), macronutrients, vitamins, and minerals and compared with the dietary reference intakes (DRIs). The prevalence of nutrient inadequacy was estimated by the proportion of athletes with mean intakes below the estimated average requirement (EAR). Energy intakes were 2,156 ± 431 kcal for men and 1,991 ± 510 kcal for women. Macronutrient intakes were within the acceptable macronutrient distribution ranges. While at training camp, >25% of men had intakes below the EAR for calcium, magnesium, zinc, riboflavin, folate, vitamin B12, and vitamin D. Thiamin, riboflavin, calcium, and vitamin D intakes were higher at home than training camp. Over 25% of women had intakes below the EAR for calcium, magnesium, folate, and vitamin D, with no significant differences in mean intakes between home and training camp. Vitamin/mineral supplement use significantly increased men’s intakes of most nutrients but did not affect prevalence of inadequacy. Women’s intakes did not change significantly with vitamin/mineral supplementation. These results demonstrate that athletes with SCI are at risk for several nutrient inadequacies relative to the DRIs.
The Effects of Acute Exercise Bouts on Hepcidin in Women
Authors: Newlin Mia K. , Williams Sara , McNamara Tim , Tjalsma Harold , Swinkels Dorine W. , Haymes Emily M.
Published: August 2016

Purpose:

To investigate the effects of acute exercise on serum hepcidin and iron (sFe) in active women. Changes in interleukin-6 (IL-6), hepcidin, ferritin, and sFe in response to 2 different exercise durations were compared.

Methods:

Twelve women age 19–32 yr performed 2 treadmill runs (60 and 120 min) at 65% of VO2max. Blood samples were obtained before, immediately after, and 3, 6, 9, and 24 hr after exercise. Two-way repeatedmeasures ANOVA was conducted to examine changes in measured variables. Significance was accepted at p < .05.

Results:

Significant effects for trial were observed for hepcidin (60 min: 1.15 ± 0.48 nmol/L; 120 min: 2.28 ± 1.44 nmol/L) and for time, with hepcidin significantly increased 3 hr postexercise in both trials (60 min: 3 hr – 1.99 ± 2.00 nmol/L; 120 min: 3 hr – 4.60 ± 4.61 nmol/L). Significant main effects for time occurred for sFe, ferritin, and IL-6. sFe was significantly decreased 9 hr postexercise compared with 3 and 24 hr postexercise. IL-6 was significantly increased immediately postexercise.

Conclusions:

Both runs resulted in significant increases in hepcidin 3 hr after exercise. Increases in hepcidin were preceded by significant increases in IL-6 immediately postexercise and followed by significant decreases in sFe 9 hr postexercise. It was concluded that endurance exercise increases the production of hepcidin, which affects sFe. The 2-hr exercise bout stimulated greater changes in serum hepcidin than the 1-hr bout.
Dietary, Anthropometric, Blood-Lipid, and Performance Patterns of American College Football Players during 8 Weeks of Training
Authors: Kirwan Rochelle D. , Kordick Lindsay K. , McFarland Shane , Lancaster Denver , Clark Kristine , Miles Mary P.
Published: August 2016

Purpose:

The purpose of this study was to determine the dietary, anthropometric, blood-lipid, and performance patterns of university-level American football players attempting to increase body mass during 8 wk of training.

Methods:

Three-day diet records, body composition (DEXA scan), blood lipids, and performance measures were collected in redshirt football players (N = 15, age 18.5 ± 0.6 yr) early season and after 8 wk of in-season training.

Results:

There was an increase (p < .05) from early-season to postseason testing for reported energy (+45%), carbohydrate (+82%), and protein (+29%) intakes and no change in the intake of fat. Fat intake was 41% of energy at the early-season test and 32% of energy at the postseason test. Increases (p < .05 for all) in performance measures, lean mass (70.5 ± 7.7–71.8 ± 7.7 kg), fat mass (15.9 ± 6.2–17.3 ± 6.8 kg), plasma total cholesterol (193.5 ± 32.4–222.6 ± 40.0 mg/dl), and low-density lipoproteins (LDL; 92.7 ± 32.7–124.5 ± 34.7 mg/dl) were measured. No changes were measured in triglycerides, very-low-density lipoproteins, or high-density lipoproteins.

Conclusion:

Increases in strength, power, speed, total body mass, muscle mass, and fat mass were measured. Cholesterol and LDL levels increased during the study to levels associated with higher risk for cardiovascular disease. It is possible that this is a temporary phenomenon, but it is cause for concern and an indication that dietary education to promote weight gain in a manner less likely to adversely affect the lipid profile is warranted.
Energy Availability of Female Varsity Volleyball Players
Authors: Woodruff Sarah J. , Meloche Renee D.
Published: August 2016

Female athletes should aim to achieve energy balance to maintain health and have a high performance output. The purpose of this study was to investigate energy availability (EA) among members of a medium-size Canadian Interuniversity Sport women’s volleyball team and to describe exercise energy expenditure (ExEE) during practices, game warm-ups, and games. Total daily energy expenditure was assessed over 7 d using the Bodymedia Sensewear Mini armband, while energy intake (EI) was measured with dietary food logs. Body composition was assessed using air-displacement plethysmography (Bod Pod). Energy availability was calculated using the equation EA = (EIkcal – ExEEkcal)/kg fat-free mass (FFM). Participants consumed 3,435 (± 1,172) kcal/day and expended 3479 (± 604) kcal/day. Mean EA was 42.5 kcal · kg FFM-1 · d-1 across all 7 d, and 2 participants fell below the 30-kcal · kg FFM-1 · d-1 threshold. Furthermore, participants expended 511 (± 216), 402 (± 50), and 848 (± 155) kcal during practices, game warm-ups, and games, respectively. Overall, the participants were relatively weight stable and should be encouraged to continue fueling their exercise and high ExEE needs with appropriate nutritional strategies.
A 6-Month Trial of Resistance Training With Milk Supplementation in Adolescents: Effects on Body Composition
Authors: Lambourne Kate , Washburn Richard , Lee Jaehoon , Betts Jessica L. , Thomas David , Smith Bryan , Gibson Cheryl , Sullivan Debra Kay , Donnelly Joseph
Published: August 2016

Fluid milk consumed in conjunction with resistance training (RT) provides additional protein and calcium, which may enhance the effect of RT on body composition. However, the literature on this topic is inconsistent with limited data in adolescents. Therefore, we examined the effects of a supervised RT program (6 mo, 3 d/wk, 7 exercises, 40–85% 1-repetition maximum) with daily milk supplementation (24 oz/day, one 16-oz dose immediately post-RT) on weight, fat mass (FM), and fat-free mass (FFM) assessed via dual-energy X-ray absorptiometry (baseline, 3 mo, 6 mo) in a sample of middle-school students who were randomly assigned to 1 of 3 supplement groups: milk, isocaloric carbohydrate (100% fruit juice), or water (control). Thirty-nine boys and 69 girls (mean age = 13.6 yr, mean BMI percentile = 85th) completed the study: milk n = 36, juice n = 34, water n = 38. The results showed no significant differences between groups for change in body weight (milk = 3.4 ± 3.7 kg, juice = 4.2 ± 3.1 kg, water = 2.3 ± 2.9 kg), FM (milk = 1.1 ± 2.8 kg, juice = 1.6 ± 2.5 kg, water = 0.4 ± 3.6 kg), or FFM (milk = 2.2 ± 1.9 kg, juice = 2.7 ± 1.9 kg, water = 1.7 ± 2.9 kg) over 6 mo. FFM accounted for a high proportion of the increased weight (milk = 62%, juice = 64%, water = 74%). These results from a sample of predominantly overweight adolescents do not support the hypothesis that RT with milk supplementation enhances changes in body composition compared with RT alone.
The Impact of Making Weight on Physiological and Cognitive Processes in Elite Jockeys
Authors: Dolan Eimear , Cullen SarahJane , McGoldrick Adrian , Warrington Giles D.
Published: August 2016

Purpose:

To examine the impact of making weight on aerobic work capacity and cognitive processes in a group of professional jockeys.

Methods:

Nine male jockeys and 9 age-, gender-, and BMI-matched controls were recruited to take part in two experimental trials, conducted 48 hr apart. The jockeys were asked to reduce their body mass by 4% in the 48 hr between trials, and controls maintained usual dietary and physical activity habits between trials. Aerobic work capacity was assessed by performance during an incremental cycle ergometer test. Motor response, decision making, executive function, and working memory were assessed using a computerized cognitive test battery.

Results:

The jockey group significantly reduced their body mass by 3.6 ± 0.9% (p < .01). Mean urine specific gravity (Usg) readings increased from 1.019 ± 0.004–1.028 ± 0.005 (p < .01) following this reduction in body mass. Peak work capacity was significantly reduced between trials in the jockey group (213 ± 27 vs. 186 ± 23 W, p < .01), although VO2peak (46.4 ± 3.7 vs. 47.2 ± 6.3 ml·kg·min-1) remained unchanged. No changes were identified for any cognitive variable in the jockey group between trials.

Conclusion:

Simulation of race day preparation, by allocating a weight that is 4% below baseline body mass caused all jockeys to report for repeat testing in a dehydrated state, and a reduction in aerobic work capacity, both of which may impact on racing performance.
Sports-Science Roundtable: Does Sports-Science Research Influence Practice?
Authors: Bishop David , Burnett Angus , Farrow Damian , Gabbett Tim , Newton Robert
Published: August 2016

As sports scientists, we claim to make a significant contribution to the body of knowledge that influences athletic practice and performance. Is this the reality? At the inaugural congress of the Australian Association for Exercise and Sports Science, a panel of well-credentialed academic experts with experience in the applied environment debated the question, Does sports-science research influence practice? The first task was to define “sports-science research,” and it was generally agreed that it is concerned with providing evidence that improves sports performance. When practices are equally effective, sports scientists also have a role in identifying practices that are safer, more time efficient, and more enjoyable. There were varying views on the need for sports-science research to be immediately relevant to coaches or athletes. Most agreed on the importance of communicating the results of sports-science research, not only to the academic community but also to coaches and athletes, and the need to encourage both short- and long-term research. The panelists then listed examples of sports-science research that they believe have influenced practice, as well as strategies to ensure that sports-science research better influences practice.
Physical Characteristics and Incidence of Injuries in Adult Figure Skaters
Authors: Ferrara Cynthia M. , Hollingsworth Emily
Published: August 2016

Purpose:

To examine relationships between physical characteristics and injuries in adult figure skaters.

Methods:

One hundred thirty adult figure skaters (113 women and 17 men, 43 ± 9 and 55 ± 10 y old, respectively) completed study questionnaires concerning health, height and weight, exercise habits, and injuries in the preceding year.

Results:

The men were older and taller and weighed more than the women (P < .05). Approximately 80% had normal body-mass index (BMI, weight [kg]/height [m]2), and the other 20% were overweight or obese based on BMI. Study participants had been skating for 12 ± 10 y (range 1 to 68 y). Most skate 4 to 5 h/wk (competitive > recreational skaters, P < .05). Although approximately 50% of competitive skaters always warm up or stretch before skating, less than 30% of the recreational skaters always do so (P < .05). Seventy-two skaters (56%) reported at least 1 injury in the preceding year. Most of the injuries were acute injuries to the lower extremity and were related to skating (76%). There were no differences in the incidence of stretching or warm-up activities or the number of hours per week spent skating in those who had incurred a skating-related injury compared with those who had not been injured (P > .05).

Conclusions:

The results suggest that adult skaters have training and exercise habits that might increase their risk of injury and impair athletic performance. This suggests the importance of educational programming for adult skaters designed to address injury prevention and basic exercise-training principles.
Influence of Performance Level on Exercise-Induced Arterial Hypoxemia During Prolonged and Successive Exercise in Triathletes
Authors: Galy Olivier , Hue Olivier , Chamari Karim , Boussana Alain , Chaouachi Anis , Préfaut Christian
Published: August 2016

Purpose:

To study the relationship between performance and exercise-induced arterial hypoxemia (EIAH), 5 internationally ranked (INT) and 8 regionally ranked (REG) triathletes performed cycle-run successions (CR) and control runs (R) in competitionlike conditions: at ≍75% VO2max.

Methods:

Ventilatory parameters and oxyhemoglo-bin saturation (SpO2) data were collected continuously. Arteriolized partial pressure in O2 (PaO2) and alveolar ventilation (VA) were measured before and after cycling (CRcycle), the successive run (CRrun), and R. Pulmonary diffusing capacity (DLco) was measured at rest and 10 minutes post-CR. Training and short-distance triathlon data were collected.

Results:

INT showed signifcantly greater experience than REG in competition years (P > .05), training regimen (P > .05), and swimming (P > .05), and cycling (P > .05) volumes; running showed a trend (P < .06). Cycling, running, and total triathlon performances were significantly higher in INT than REG (P > .01). SpO2 during CR dropped significantly more in INT than in REG. Both groups showed significant inverse correlations between the magnitude of the SpO2 change from CRcy-cle to CRrun and the triathlon running time (r = −0.784; P < .05 and r = −0.699; P < .05; respectively). When compared with CRcycle, PaO2 significantly decreased and VA significantly increased after CRrun and R in both groups (P < .01). DLco significantly dropped between pre- and postexercise in CR and R with no between-group difference (P < .05).

Conclusions:

EIAH was aggravated in higher performers during simulated cycle-run segments, related to longer experience and heavier training regimens. Possibly, relative hypoventilation caused this aggravated EIAH in INT, although pulmonary diffusion limitation was observed in both groups. Beyond EIAH severity, the magnitude of SpO2 variations during the cycle-run transition may affect triathlon running performance.
Vitamin C Supplementation and Salivary Immune Function Following Exercise-Heat Stress
Authors: Carrillo Andres E. , Murphy René J. L. , Cheung Stephen S.
Published: August 2016

Purpose:

Prolonged physical exertion and environmental heat stress may elicit postexercise depression of immune cell function, increasing upper respiratory tract infection (URTI) susceptibility. We investigated the effects of acute and short-term vitamin C (VC) compared with placebo (PL) supplementation on URTI susceptibility, salivary immunoglobulin A (s-IgA), and cortisol responses in healthy individuals following prolonged exercise-heat stress.

Methods:

Twelve participants were randomized into the VC or PL group in a double-blind design. For 12 days, participants consumed 3 × 500 mg tablets of VC or PL per day, with testing completed at baseline, then following acute (1 d) and short-term (8 d) supplementation. Participants performed 120.1 ± 49.6 min of cycling at 54 ± 6% VO2max in a hot (34.8 ± 1.0°C and 13 ± 3% relative humidity) environment, with saliva samples collected at pre-, post-, and 72 h postexercise. Health logs specifying URTI symptoms were completed for 7 days postexercise.

Results:

A 2 × 3 × 3 mixed ANOVA with a post hoc Bonferroni correction factor revealed a significant linear trend in postexercise cortisol attenuation in the VC group, 21.7 ± 15.1 nmol/L (mean ± SD) at baseline, to 13.5 ± 10.0 at acute, to 7.6 ± 4.2 after short term (P = .032). No differences were detected in ratio of s-IgA to protein or URTI symptoms between groups.

Conclusions:

These data suggest that vitamin C supplementation can decrease postexercise cortisol in individuals performing exercise similar to that of a half-marathon or marathon in hot conditions. However, no changes in s-IgA and URTI were evident, possibly due to previous moderate training and reduced physical and psychological stress compared with athletes participating in ultramarathons.
The Effect of 45 Minutes of Soccer-Specific Exercise on the Performance of Soccer Skills
Authors: Stone Keeron J. , Oliver Jonathan L.
Published: August 2016

Purpose:

The aim of the study was to examine the effect of fatigue, developed during prolonged high-intensity intermittent exercise, on the performance of soccer shooting and dribbling skill.

Methods:

Nine semiprofessional soccer players with a mean age of 20.7 ± 1.4 years volunteered to participate in the study. Participants completed a slalom dribble test and the Loughborough Soccer Shooting Test (LSST), before and directly following the performance of three 15-min bouts of a modified version of the Loughborough Intermittent Shuttle Test (LIST).

Results:

Mean heart rates and mean 15-m sprint times remained unchanged across the three bouts of the LIST. Following the LIST slalom dribbling time increased significantly by 4.5 ± 4.0% (P = .009), while the mean total points scored during the LSST was significantly reduced by 7.6 ± 7.0 points (P = .012). When fatigued the frequency of shots in the LSST achieving the highest score of 5 points was reduced by 47% while the frequency of shots achieving the lowest 0 point score increased by 85%.

Conclusion:

Results show that while 45 min of exercise caused no decrements in sprint performance there were significant reductions in the ability to perform soccer-specific skills. Both the speed (dribbling time) and accuracy (shot performance) with which soccer-specific skills were executed was impaired following exercise replicating one-half of a soccer match.
Training Methods and Intensity Distribution of Young World-Class Rowers
Authors: Arne Guellich , Stephen Seiler , Eike Emrich
Published: August 2016

Purpose:

To describe the distribution of exercise types and rowing intensity in successful junior rowers and its relation to later senior success.

Methods:

36 young German male rowers (31 international, 5 national junior finalists; 19.2 ± 1.4 y; 10.9 ± 1.6 training sessions per week) reported the volumes of defined exercise and intensity categories in a diary over 37 wk. Training categories were analyzed as aggregates over the whole season and also broken down into defined training periods. Training organization was compared between juniors who attained national and international senior success 3 y later.

Results:

Total training time consisted of 52% rowing, 23% resistance exercise, 17% alternative training, and 8% warm-up programs. Based on heart rate control, 95% of total rowing was performed at intensities corresponding to <2 mmol·L-1, 2% at 2 to 4 mmol·L-1, and 3% at >4 mmol·L-1 blood lactate. Low-intensity work remained widely unchanged at ~95% throughout the season. In the competition period, the athletes exhibited a shift within <2 mmol exercise toward lower intensity and within the remaining ~5% of total rowing toward more training near maximal oxygen consumption (VO2max) intensity. Retrospectively, among subjects going on to international success 3 y later had their training differed significantly from their peers only in slightly higher volumes at both margins of the intensity scope.

Conclusion:

The young world-class rowers monitored here exhibit a constant emphasis on low-intensity steady-state rowing exercise, and a progressive polarization in the competition period. Possible mechanisms underlying a potential association between intensity polarization and later success require further investigation.
Hyperthermic Fatigue Precedes a Rapid Reduction in Serum Sodium in an Ironman Triathlete: A Case Report
Authors: Laursen Paul B. , Watson Greig , Abbiss Chris R. , Wall Bradley A. , Nosaka Kazunori
Published: August 2016

Purpose:

To monitor the hydration, core temperature, and speed (pace) of a triathlete performing an Ironman triathlon.

Methods:

A 35-year-old experienced male triathlete participated in the Western Australian Ironman triathlon on December 1, 2006. The participant was monitored for blood Na+ concentration before the race (PRE), at the transitions (T1 and T2), halfway through the run (R21), and after the race (POST; 2hPOST). Core body temperature (T ; pill telemetry) was recorded continuously, and running speed (s3 stride sensor) was measured during the run.

Results:

The participant completed the race in 11 h 38 min, in hot conditions (26.6 ± 5.8°C; 42 ± 19% rel. humidity). His Tc increased from 37.0 to 38.6°C during the 57-min swim, and averaged 38.4°C during the 335-min bike (33.5 km·h-1). After running at 12.4 km·h-1 for 50 min in the heat (33.1°C), T increased to 39.4°C, before slowing to 10.0 km·h-1 for 20 min. T decreased to 38.9°C until he experienced severe leg cramps, after which speed diminished to 6 km·h-1 and T fell to 38.0°C. The athlete’s blood Na+ was constant from PRE to T2 (139-140 mEq·L-1, but fell to 131 mEq·L-1 at R21, 133 mEq·L-1 at POST, and 128 mEq·L-1at 2hPOST The athlete consumed 9.25 L of fuid from PRE to T2, 6.25 L from T2 to POST, and lost 2% of his body mass, indicating sweat losses greater than 15.5 L.

Conclusion:

This athlete slowed during the run phase following attainment of a critically high T and experienced an unusually rapid reduction in blood Na+ that preceded cramping, despite presenting with signs of dehydration.
Influence of Temperature and Performance Level on Pacing a 161 km Trail Ultramarathon
Authors: Parise Carol A. , Hoffman Martin D.
Published: August 2016

Background:

Even pacing has been recommended for optimal performances in running distances up to 100 km. Trail ultramarathons traverse varied terrain, which does not allow for even pacing.

Purpose:

This study examined differences in how runners of various abilities paced their efforts in the Western States Endurance Run (WSER), a 161 km trail ultramarathon in North America, under hot vs cooler temperatures.

Method:

Temperatures in 2006 (hot) and 2007 (cooler) ranged from 7-38°C and 2-30°C, respectively. Arrival times at 13 checkpoints were recorded for 50 runners who finished the race in both years. After stratification into three groups based on finish time in 2007 (<22, 22-24, 24-30 h), paired t tests were used to compare the difference in pace across checkpoints between the years within each group. The χ2 test was used to compare differences between the groups on the number of segments run slower in the hot vs cooler years.

Results:

For all groups, mean pace across the entire 161 km race was slower in 2006 than in 2007 (9:23 ± 1:13 min/km vs 8:42 ± 1:15 min/km, P < .001) and the pace was slower from the start of the race when temperatures were still relatively cool. Overall, the <22 h cohort ran slower in 2006 than 2007 over 12 of the 14 segments examined, the 22–24 h cohort was slower across 10 of the segments, and the >24 h cohort was slower across only 6 of the segments χ22 = 6.00, P = .050). Comparable pacing between the 2 y corresponded with onset of nighttime and cooling temperatures.

Conclusions:

Extreme heat impairs all runners’ ability to perform in 161 km ultramarathons, but faster runners are at a greater disadvantage compared with slower competitors because they complete a greater proportion of the race in the hotter conditions.
Changes in a Top-Level Soccer Referee’s Training, Match Activities, and Physiology Over an 8-Year Period: A Case Study
Authors: Weston Matthew , Gregson Warren , Castagna Carlo , Breivik Simon , Impellizzeri Franco M. , Lovell Ric J.
Published: August 2016

Athlete case studies have often focused on the training outcome and not the training process. Consequently, there is a dearth of information detailing longitudinal training protocols, yet it is the combined assessment of both outcome and process that enhances the interpretation of physical test data. We were provided with a unique opportunity to assess the training load, physical match performance, and physiological fitness of an elite soccer referee from the referee’s final season before attaining full-time, professional status (2002) until the season when he refereed the 2010 UEFA Champions League and FIFA World Cup finals. An increased focus on on-field speed and gym-based strength training was observed toward the end of the study period and longitudinal match data showed a tendency for decreased total distances but an increased intensity of movements. Laboratory assessments demonstrated that VO2max remained stable (52.3 vs 50.8 mL-kg–1-min–1), whereas running speed at the lactate threshold (14.0 vs 12.0 km-h-1) and running economy (37.3 vs 43.4 mLkg–1min–1) both improved in 2010 compared with 2002.
The Effect of a Second Runner on Pacing Strategy and RPE During a Running Time Trial
Authors: Bath Deryn , Turner Louise A. , Bosch Andrew N. , Tucker Ross , Lambert Estelle V. , Thompson Kevin G. , Gibson Alan St. Clair
Published: August 2016

Purpose:

The aim of this study was to examine performance, pacing strategy and perception of effort during a 5 km time trial while running with or without the presence of another athlete.

Methods:

Eleven nonelite male athletes participated in five 5 km time trials: two self-paced, maximal effort trials performed at the start and end of the study, and three trials performed in the presence of a second runner. In the three trials, the second runner ran either in front of the subject, behind the subject, or next to the subject. Performance times, heart rate, RPE, and a subjective assessment of the effect of the second runner on the athlete’s performance were recorded during each of the trials.

Results:

There was no significant difference in performance times, heart rate or RPE between any of the five trials. Running speed declined from the 1st to the 4th kilometer and then increased for the last kilometer in all five trials. Following the completion of all trials, 9 of the 11 subjects perceived it to be easier to complete the 5 km time trial with another runner in comparison with running alone.

Conclusions:

While the athletes perceived their performance to be improved by the presence of another runner, their pacing strategy, running speed, heart rate and RPE were not significantly altered. These findings indicate that an athlete’s subconscious pacing strategy is robust and is not altered by the presence of another runner.
Quantifying the Gap Between Under 18 and Senior AFL Football: 2003 and 2009
Authors: Burgess Darren , Naughton Geraldine , Norton Kevin
Published: August 2016

Purpose:

The understanding of the gap between Under 18 y (U18) and senior-level competition and the evolution of this gap in Australian Football lack a strong evidence base. Despite the multimillion dollars invested in recruitment, scientific research on successful transition is limited. No studies have compared individual players’ movement rate, game statistics and ball speed in U18 and senior competition of the Australian Football League across time. This project compared differences in player movement and ball speed between matches from senior AFL competitive matches and U18 players in the 2003 and 2009 seasons.

Methods:

TrakPerformance Software and Global Positioning System (GPS) technology were used to analyze the movement of players, ball speed and game statistics. ANOVA compared the two levels of competition over time.

Results:

Observed interactions for distance traveled per minute of play (P = .009), number of sprints per minute of play (P < .001), time spent at sprint speed in the game (P < .001), time on field (P < .001), and ball speed (P < .001) were found. Subsequent analysis identified increases in movement patterns in senior AFL competition in 2009 compared with the same level of competition in 2003 and U18 players in 2003 and 2009.

Conclusions:

Senior AFL players in 2009 were moving further, sprinting relatively more frequently, playing less time and playing at game speeds significantly greater than the same senior competition in 2003 as well as compared with both cohorts of U18 players.
Effects of Short-Term Training With Uncoupled Cranks in Trained Cyclists
Authors: Burns Jack M. , Peiffer Jeremiah J. , Abbiss Chris R. , Watson Greig , Burnett Angus , Laursen Paul B.
Published: August 2016

Purpose:

Manufacturers of uncoupled cycling cranks claim that their use will increase economy of motion and gross efficiency. Purportedly, this occurs by altering the muscle-recruitment patterns contributing to the resistive forces occurring during the recovery phase of the pedal stroke. Uncoupled cranks use an independent-clutch design by which each leg cycles independently of the other (ie, the cranks are not fixed together). However, research examining the efficacy of training with uncoupled cranks is equivocal. The purpose of this study was to determine the effect of short-term training with uncoupled cranks on the performance-related variables economy of motion, gross efficiency, maximal oxygen uptake (VO2max), and muscle-activation patterns.

Methods:

Sixteen trained cyclists were matched-paired into either an uncoupled-crank or a normal-crank training group. Both groups performed 5 wk of training on their assigned cranks. Before and after training, participants completed a graded exercise test using normal cranks. Expired gases were collected to determine economy of motion, gross efficiency, and VO2max, while integrated electromyography (iEMG) was used to examine muscle-activation patterns of the vastus lateralis, biceps femoris, and gastrocnemius.

Results:

No significant changes between groups were observed for economy of motion, gross efficiency, VO2max, or iEMG in the uncoupled- or normal-crank group.

Conclusions:

Five weeks of training with uncoupled cycling cranks had no effect on economy of motion, gross efficiency, muscle recruitment, or VO2max compared with training on normal cranks.
Warm-Up Practices in Elite Snowboard Athletes
Authors: Sporer Ben C. , Cote Anita , Sleivert Gordon
Published: August 2016

Purpose:

The purpose of this project was to observe current warm-up practices in snowboard athletes and evaluate their physiological impact before competition.

Methods:

An observational design was used to monitor 4 athletes (2 female) at an Open National Snowboard Cross Championships. Activity patterns, core temperature, heart rate (HR), and time between warm-up and competition were measured. Athlete ratings of thermal comfort (TC) and thermal sensation (TS) were recorded before competition.

Results:

Significant barriers and challenges to an optimal warm-up included delays, environment, and logistics. Time gaps between structured warm-up and competition start time were in excess of 1 h (median = 68.8 min). Median average HR for 10 min (HR10) did not exceed 120 beats/min in the hour preceding competition, suggesting a suboptimal warmup intensity. Athletes rated their TC between comfortable and slightly uncomfortable and TS as neutral to slightly warm before the start of qualifications and finals.

Conclusions:

The observations of this project suggest significant gaps in current warm-up strategies used in snowboarding. These include inadequate general aerobic warm-up (based on intensity and duration), excessive time between warm-up and competition, and lack of a consistent and structured warm-up protocol. Future work is needed to evaluate the effectiveness of different warm-up strategies on muscle temperature and performance while determining the optimal length of time between warm-up and competition.
Game Location Moderates the Relationship Between Anticipatory Testosterone Changes and Athletic Performance
Authors: Putnam Susan K. , Carré Justin M.
Published: August 2016

The authors examined the extent to which changes in testosterone concentrations before competition would be associated with performance among elite male hockey players. Saliva samples were collected on 2 noncompetition days (baseline) and before 2 playoff games (1 home game, 1 away game). Individual performance was assessed by the coaching staff after each game. Results indicated that changes in testosterone before competition predicted performance, but this effect was influenced by game location. Unexpectedly, the authors found a significant negative relationship between a rise in testosterone and performance for the away game and a nonsignificant positive relationship for the home game. These findings indicate that game location should be considered in studies examining the neuroendocrine correlates of athletic competition.