Red blood cell omega-3 fatty acid content is negatively associated with purposeful gameplay header frequencies in collegiate women soccer players: Implications for diet and brain health.

Background: Frequent soccer heading negatively affects brain health. Omega-3 fatty acids are neuroprotective against head impacts. A biomarker of omega-3 tissue status, red blood cell (RBC) omega-3 content is reduced during soccer activity. However, whether these changes are associated with frequent heading impacts is unknown. Aim: Explore the association between soccer heading frequencies and RBC omega-3 status. Methods: A prospective cohort study in collegiate women soccer players (n = 16). Players' RBC omega-3 status, Omega-3 Index, and self-reported gameplay header frequencies collected during a competitive season. Results: Mean Omega-3 Index (i.e., pre/postseason) was low (3.95 ± 0.44%). Postseason Omega-3 Index negatively correlated (r = -0.545, p = 0.029) with heading frequencies. Change in Omega-3 Index negatively correlated (r = -0.663, p = 0.005) with average headers per game. Conclusion: RBC omega-3 status is negatively influenced by frequent soccer heading throughout a competitive season which may have concerning implications for player brain health.

Creatine as a Therapeutic Target in Alzheimer's Disease.

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease, affecting approximately 6.5 million older adults in the United States. Development of AD treatment has primarily centered on developing pharmaceuticals that target amyloid-ß (Aß) plaques in the brain, a hallmark pathological biomarker that precedes symptomatic AD. Though recent clinical trials of novel drugs that target Aß have demonstrated promising preliminary data, these pharmaceuticals have a poor history of developing into AD treatments, leading to hypotheses that other therapeutic targets may be more suitable for AD prevention and treatment. Impaired brain energy metabolism is another pathological hallmark that precedes the onset of AD that may provide a target for intervention. The brain creatine (Cr) system plays a crucial role in maintaining bioenergetic flux and is disrupted in AD. Recent studies using AD mouse models have shown that supplementing with Cr improves brain bioenergetics, as well as AD biomarkers and cognition. Despite these promising findings, no human trials have investigated the potential benefits of Cr supplementation in AD. This narrative review discusses the link between Cr and AD and the potential for Cr supplementation as a treatment for AD.

Interassociation Consensus Statement on Sports Nutrition Models for the Provision of Nutrition Services From Registered Dietitian Nutritionists in Collegiate Athletics.

Collegiate athletic programs are increasingly adding nutrition services to interdisciplinary sports medicine and sports performance departments in response to scientific evidence highlighting nutrition's integral role in supporting athletic performance and overall health. Registered Dietitian Nutritionists (RDNs) specializing in sports dietetics (ie, sports RDNs) and credentialed Board-certified Specialists in Sports Dietetics (CSSDs) are the preferred nutrition service providers for these programs. Their extensive training and proficiency in medical nutrition therapy, education and behavioral counseling, food-service management, exercise physiology, physical performance, and administration, as defined by the "Standards of Practice and "Standards of Professional Performance" for Registered Dietitian Nutritionists in Sports Nutrition and Human Performance," make these practitioners uniquely qualified to deliver the breadth of care required in the collegiate setting. Therefore, this document, guided by a multidisciplinary panel, introduces 4 sports nutrition models through which any collegiate athletic program can deliver sports RDN-directed nutrition services. In each model, the most effective staffing and scope of service are indicated and reviewed. In addition, recommended organizational structures for sports RDNs are provided that best support the delivery of the model's nutrition services in a variety of collegiate athletic programs and organizational settings. Lastly, future research initiatives and nutrition interventions to help improve the standard of care through these sport nutrition models are explored.

Anthropometric Factors Associated With Bone Stress Injuries in Collegiate Distance Runners: New Risk Metrics and Screening Tools?

BACKGROUND: Lower limb bone stress injury (BSI) of the pelvis, femur, and tibia is prevalent in collegiate track and field distance runners. Bone mineral density (BMD), body composition (BComp), and anthropometric parameters before initial collegiate injury have not been compared between runners with BSI and their noninjured counterparts. PURPOSE: To characterize bone health in relation to BComp and anthropometric measurements from total-body dual x-ray absorptiometry (DXA) scans in collegiate male and female distance runners before BSI and develop BMD prediction models. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: Distance runners (N = 79) from a single university track and field team were retrospectively enrolled into this study. The runners completed a DXA scan during the fall season (August-November) and participated in sport activities before the scan. Three months after scanning, electronic medical records were reviewed for the occurrence of BSI. An independent-sample t test was used to compare BMD (total and regional [spine, pelvis, and legs]), BComp (% body fat, fat mass, and lean mass), and anthropometric measurements (shoulder width and leg, arm, and trunk length) between runners with versus without BSI (included subgroup analysis by sex). Multiple linear regression with stepwise removal was used to determine variables most predictive of BMD. RESULTS: Of the 79 enrolled participants (42 male, 37 female), 18 runners (22.8%; 11 female, 7 male) sustained a lower limb BSI. Compared with the noninjured group, injured runners had lower total and regional BMD (P < .001 for all) and shorter leg and arm lengths (P < .05 for both), whereas injured male runners had lower fat mass and injured female runners had lower lean mass in the legs (P < .05 for both). Injured runners' age-matched total BMD Z score (-0.1 ± 0.6) was considered clinically normal. BComp and anthropometric measures were predictive of total and regional BMD (P < .05; R 2 = 0.64-0.80; percentage error = 3.8%-4.8%). CONCLUSION: The DXA scans of injured runners prior to incidence indicated lower BMD compared with noninjured runners. Shorter limb lengths, lower fat mass (male), and lower leg lean mass (female) may also be indicative of risk. Certain BComp and anthropometric measures were predictive of BMD.

Assessing Omega-3 Intake in Sport: the Brief Food Frequency Questionnaire and the Omega-3 Index in Collegiate Women Soccer Players.

CONTEXT: Omega-3 fatty acids modulate inflammatory processes and are considered beneficial for sport populations, highlighting a need to assess omega-3 intake in a practical manner. Food frequency questionnaires (FFQs) are inexpensive, noninvasive tools aimed at evaluating nutrient intakes such as omega-3 fatty acids. In healthy adults, a tailored, brief FFQ for estimating omega-3 intake was associated with the erythrocyte omega-3 fatty acid level, a biomarker for omega-3 tissue status and indicative of intake. However, the association between a brief omega-3 FFQ and erythrocyte levels, particularly the Omega-3 Index (eicosapentaenoic acid [EPA], docosahexaenoic acid [DHA], and EPA + DHA), has yet to be explored in a sport population. OBJECTIVE: To examine the association between omega-3 intake using a brief FFQ and the Omega-3 Index in collegiate women soccer players. DESIGN: Cross-sectional study. SETTING: University sport team. PATIENTS OR OTHER PARTICIPANTS: Thirty-one National Collegiate Athletic Association Division I collegiate women soccer players. MAIN OUTCOME MEASURE(S): The brief omega-3 FFQ assessed dietary omega-3 intake: DHA and EPA. The OmegaQuant blood test measured erythrocyte omega-3 fatty acid (EPA, DHA) and Omega-3 Index (EPA + DHA) levels. RESULTS: Brief FFQ intakes of EPA, DHA, and EPA + DHA were positively correlated with the erythrocyte EPA (r = 0.48, P = .007), DHA (r = 0.73, P < .001), and Omega-3 Index (r = 0.73, P < .001). CONCLUSIONS: In a sample of collegiate women soccer players, the brief omega-3 FFQ was correlated with erythrocyte omega-3 fatty acid levels and may offer health practitioners a practical tool for assessing omega-3 intake in this collegiate sport population.

The effect of omega-3 fatty acids on a biomarker of head trauma in NCAA football athletes: a multi-site, non-randomized study.

BACKGROUND: American-style football (ASF) athletes are at risk for cardiovascular disease (CVD) and exhibit elevated levels of serum neurofilament light (Nf-L), a biomarker of axonal injury that is associated with repetitive head impact exposure over the course of a season of competition. Supplementation with the w-3 fatty acid (FA) docosahexaenoic acid (DHA) attenuates serum Nf-L elevations and improves aspects of CVD, such as the omega-3 index (O3I). However, the effect of combining the w-3 FA eicosapentaenoic acid (EPA) and docosapentaenoic acid (DPA) with DHA on, specifically, serum Nf-L in ASF athletes is unknown. Therefore, this study assessed the effect of supplemental w-3 FA (EPA+DPA+DHA) on serum Nf-L, plasma w-3 FAs, the O3I, and surrogate markers of inflammation over the course of a season. METHODS: A multi-site, non-randomized design, utilizing two American football teams was employed. One team (n = 3 1) received supplementation with a highly bioavailablew-3 FA formulation (2000mg DHA, 560mg EPA, 320mg DPA, Mindset®, Struct Nutrition, Missoula, MT) during pre-season and throughout the regular season, while the second team served as the control (n = 35) and did not undergo supplementation. Blood was sampled at specific times throughout pre- and regular season coincident w ith changes in intensity, physical contact, and changes in the incidence and severity of head impacts. Group differences were determined via a mixed-model between-within subjects ANOVA. Effect sizes were calculated using Cohen's dfor all between-group differences. Significance was set a priori at p< .05. RESULTS: Compared to the control group, ASF athletes in the treatment group experienced large increases in plasma EPA (p < .001, d = 1.71) and DHA (p < .001, d = 2.10) which contributed to increases in the O3I (p < .001, d = 2.16) and the EPA:AA ratio (p = .001, d = 0.83) and a reduction in the w-6: w-3 ratio (p < .001, d = 1.80). w-3 FA supplementation attenuated elevations in Nf-L (p = .024). The control group experienced a significant increase in Nf-L compared to baseline at several measurement time points (T2, T3, and T4 [p range < .001 - .005, drange = 0.59-0.85]). CONCLUSIONS: These findings suggest a cardio- and neuroprotective effect of combined EPA+DPA+DHA w-3 FA supplementation in American-style football athletes. TRIAL REGISTRATION: This trial was registered with the ISRCTN registry ( ISRCTN90306741 ).

Positional Body Composition of Female Division I Collegiate Volleyball Players.

Bisch, KL, Bosch, TA, Carbuhn, A, Stanforth, PR, Oliver, JM, Bach, CW, and Dengel, DR. Positional body composition of female division I collegiate volleyball players. J Strength Cond Res 34(11): 3055-3061, 2020-The primary study objective was to measure positional differences in total and regional body composition among female NCAA Division I collegiate volleyball players using dual X-ray absorptiometry (DXA). The secondary objective was to examine normative age curves for fat and lean mass (LM) variables. Ninety female volleyball players from 5 universities received a DXA scan. Athletes were categorized by position: middle blocker (MB = 31), outside hitter (OH = 32), setter (ST = 9), and Libero (LB = 18). Height, body mass, total and regional fat mass (FM), LM, bone mineral density (BMD), and abdominal visceral adipose tissue were measured by DXA. Body mass distribution ratios were calculated. The secondary age analysis included a subset of 153 DXA scans (n = 83, ages 18-21 years). Front row players (i.e., MB and OH) had significantly greater total and regional LM and BMD measures (p < 0.05, all), compared with non-front row players (i.e., LB and ST). Differences in total LM (p < 0.001) were significantly influenced by height. Front row players had consistently lower mass distribution ratios compared with non-front row players (p < 0.05, all). Lean mass index (LMI, p = 0.752) and FM index (FMI, p = 0.392) were not significantly different across ages. Back row players have greater relative upper body mass, whereas mass in front row players is more evenly distributed between the upper and lower body. Bone mineral density differences may be influenced by repeated impact of jumping during the attacking and blocking actions of front row players. Minimal changes in LMI and fluctuations in FMI can be expected across an athlete's career.

Body Composition of National Collegiate Athletic Association (NCAA) Division I Female Soccer Athletes through Competitive Seasons.

The purpose of this study was to examine body composition of National Collegiate Athletic Association Division I female soccer players by position and season. One hundred seventy-five female athletes were categorized by positions of forward (n=47), midfielder (n=51), defender (n=57), and goalkeeper (n=20). A dual X-ray absorptiometry scan assessed percent body fat, total lean mass, total fat mass, arm and leg lean mass and fat mass, and visceral adipose tissue. Goalkeepers had significantly higher total, arm, and leg lean mass and fat mass compared to all other positions (p<0.05). For seasonal changes, body fat percentage was significantly higher in winter off-season (26.7%) compared to summer off-season (25.7%) and pre-season (25.8%; p<0.01) for all positions. Total and leg lean mass was significantly lower in winter off-season compared to all other seasons, and total lean mass was significantly higher in summer off-season than pre-season (p<0.01). Overall, goalkeepers were significantly different than all other positions. Body fat percentage increased and lean mass decreased in winter off-season indicating potential undesired changes in training and/or nutrition over the break whereas lean mass was the highest in summer off-season potentially reflecting the emphasis on resistance training and increased volume of training.

Total and Regional Body Composition of NCAA Division I Collegiate Basketball Athletes.

This study aimed to examine body composition using dual X-ray absorptiometry (DXA) in male and female NCAA Division I collegiate basketball athletes. Two-hundred ten (male [M]/female [F]=88/122) basketball athletes' total and regional fat mass, lean mass, bone mineral density, and visceral adipose tissue were measured. Athletes were classified as: point guards (M/F=27/34), shooting guards (M/F=18/27), small forwards (M/F=13/18), power forwards (M/F=21/27), and centers (M/F=9/16). ANOVA and Tukey's HSD assessed positional differences by sex. In males, centers and power forwards had greater total fat mass (p<0.025), lean mass (p≤0.001), and visceral adipose tissue (p<0.001) than other positions. Male centers had greater arm and leg fat mass and lean mass than point guards, shooting guards, and small forwards (p≤0.049), and greater arm bone mineral density than point guards (p=0.015). In females, centers had greater total fat mass (p<0.001) vs. other positions and greater total lean mass, arm fat and lean masses, arm and leg bone mineral density, and visceral adipose tissue vs. point guards and shooting guards (p≤0.005). Female point guards had lower total bone mineral density than power forwards (p=0.008). In conclusion, these sex- and position-specific total and regional body composition measurements in collegiate basketball players provide population-specific normative data.

Body Composition and Bone Mineral Density of Division 1 Collegiate Track and Field Athletes, a Consortium of College Athlete Research (C-CAR) Study.

The purpose of the present study was to generate normative values for total and regional body composition in male and female Division 1 collegiate track and field athletes using dual X-ray absorptiometry. We also sought to examine body composition by event and sex. Data were used from the Consortium of College Athlete Research group. A total of 590 (male [M]/female [F] = 274/316) athletes had their height, weight, total and regional fat mass (FM), lean mass, and bone mineral density (BMD) measured. Athletes were classified into 1 of 7 categories: Jumps (M/F = 28/30); Long Distance (M/F = 104/110), Middle Distance (M/F = 27/24), Multievent (M/F = 11/9), Pole Vault (M/F = 21/27), Sprints (M/F = 54/96), and Throws (M/F = 29/20). Total and regional differences between events and sex were assessed by analysis of variance. Except for male and female throwers, all other track and field athletes' mean percent body fat (M: 10.3%-12.6%, F: 17.5%-21.6%) and visceral FM (<500 g) was low, but in a healthy range. As expected, throwers had significantly (p < 0.05) higher total and regional FM and lean mass than other events. In addition, male (1.55 ± 0.11 g/cm2) and female (1.40 ± 0.12 g/cm2) throwers had significantly greater BMD than all other events while male (1.25 ± 0.10 g/cm2) and female (1.16 ± 0.09 g/cm2) distance runners had significantly lower BMD than all other events. In conclusion, track athletes' body composition differed across events for both males and females. These measurements provide normative data on NCAA Division 1 male and female track and field athletes.

A Simplified Prediction Model for Lower Extremity Long Bone Stress Injuries in Male Endurance Running Athletes.

OBJECTIVE: Develop a prediction model for lower extremity long bone injuries (LBIs) in male endurance running athletes using dual-energy x-ray absorptiometry (DEXA). DESIGN: Retrospective. SETTING: Sports medicine department in a university athletic setting. PARTICIPANTS: National Collegiate Athletic Association (NCAA) Division 1 white male endurance athletes (n = 27). INDEPENDENT VARIABLES: Backward stepwise elimination was used to achieve a model that predicts LBI, by removing noncontributory variables (P > 0.10), using binary logistic regression. Independent prediction variables analyzed for model were as follows: (1) height (cm), body mass index (BMI) (kg/m), and total mass (kg); and (2) regional and total lean mass, fat mass, and bone density assessed using DEXA. MAIN OUTCOME MEASURES: Dichotomous dependent variable was LBI. RESULTS: Final constructed model predicted 96.3% of athletes with and without LBI. Prediction model were as follows: predict lower extremity long bone stress injury = 23.465 - 0.896 BMI + 1.043 (total upper-body mass) TUB - 34.536 leg bone mineral density (BMD). Predict lower extremity long bone stress injury is the LBI prediction, and TUB (kg) is total fat, muscle, and bone weight in trunk and arms. CONCLUSIONS: These preliminary data suggest that Division 1 white male endurance running athletes are at risk of LBI with higher relative TUB and lower BMI in combination with a lower leg BMD.

Total and Regional Body Composition of NCAA Division I Collegiate Female Softball Athletes.

The purpose of this study was to evaluate total, regional, and throwing versus non-throwing arm body composition measures across the 4 major positions of NCAA Division I female softball players using dual X-ray absorptiometry (DXA) (n=128). Total and regional total mass (TM), fat mass (FM), lean mass (LM), bone mineral density (BMD), bone mineral content (BMC), and visceral adipose tissue were measured. Athletes were separated into: pitchers (n=32), catchers (n=13), outfielders (n=39), and infielders (n=44). ANOVA and Tukey's HSD assessed total and regional differences between positions. Although no significant total or regional LM differences were observed across positions, outfielders had significantly (p=0.006-0.047) lower total-body, arm, and trunk TM and FM, leg FM, and leg BMC in comparison to pitchers. The throwing arm had significantly (p<0.0001-0.018) greater LM, BMD, and BMC than the non-throwing arm for all positions. Notably, there were minimal body composition differences among softball positions, with the primary differences being that pitchers had larger total and regional fat values than outfielders. The throwing arm of all positions had greater LM, BMD, and BMC than the non-throwing arm. These values can be used by coaches and trainers as descriptive DXA data for collegiate softball players.

Total and Regional Body Composition of NCAA Division I Collegiate Baseball Athletes.

This study's purpose was to evaluate total, regional, and throwing versus non-throwing arm body composition measurements between various positions of NCAA Division I male baseball players using dual X-ray absorptiometry (DXA). Two hundred and one collegiate baseball athletes were measured using DXA. Visceral adipose tissue (VAT), total and regional fat mass (FM), lean mass (LM), and bone mineral density (BMD) were measured. Athletes were separated into: pitchers (n=92), catchers (n=25), outfielders (n=43), and infielders (n=41). ANOVA and Tukey's honest significant difference assessed total and regional differences between positions. Infielders had significantly (p<0.05) lower total LM than pitchers and outfielders. Additionally, outfielders had significantly lower total FM compared to pitchers and catchers. No significant differences between positions were observed for total BMD and VAT. Pitchers' and infielders' throwing arm demonstrated significantly greater total mass, FM, LM, and BMD compared to the non-throwing arm. Further, outfielders' throwing arm total mass, LM, and BMD were significantly higher vs. the non-throwing arm. Significant differences were observed in total and regional body composition measurements across position, in addition to differences in throwing arm vs. non-throwing arm composition. These measurement values are important to coaches and trainers as normative positional DXA data for collegiate baseball players.

Predicting V[Combining Dot Above]O2max From Treadmill Performance in American-Style Football Athletes.

Crouse, SF, Tolson, H, Lytle, J, Johnson, KA, Martin, SE, Green, JS, Oliver, J, Carbuhn, A, Lambert, B, and Bramhall, JP. Predicting V[Combining Dot Above]O2max from treadmill performance in American-style football athletes. J Strength Cond Res 33(4): 1028-1034, 2019-Prediction equations are often used to estimate V[Combining Dot Above]O2max in the general population but are lacking for American-style football (ASF) athletes. We sought to develop a regression model to estimate V[Combining Dot Above]O2max from treadmill exercise time in ASF athletes and compare our football V[Combining Dot Above]O2max model with 2 published prediction equations (Foster et al., 1984, and Bruce, 1973). American-style football athletes (N = 472, age = 18 ± 1 year, height = 186.1 ± 8.2 cm, and body mass = 101.8 ± 20.4 kg) underwent treadmill exercise to voluntary exhaustion (Bruce protocol). Maximal exercise time was recorded in minutes (Tmin), and V[Combining Dot Above]O2max was simultaneously measured (M-V[Combining Dot Above]O2max, mlO2·kg·min) by an automated gas-analysis system. Athletes were then randomly divided into validation and cross-validation groups (n = 236). Linear regression yielded estimates of V[Combining Dot Above]O2max from Tmin as follows: validation V[Combining Dot Above]O2max = 4.012 × Tmin - 4.628 (r = 0.678, p < 0.001, and SEE = 4.07); cross-validation V[Combining Dot Above]O2max = 4.025 × Tmin - 4.693 (r = 0.661, p < 0.001, and SEE = -4.16). These equations had a cross-validation coefficient of 0.813 and a double cross-validation coefficient of 0.823. Differences between the slopes of the 2 equations were not significant (t-test, p = 0.9603). Because validation and cross-validation groups were not statistically different on any variables measured (multivariate analysis of variance, p > 0.05), all athletes were combined to yield our final prediction equation: football V[Combining Dot Above]O2max = 4.017 × Tmin - 4.644 (r = 0.670, p < 0.001, and SEE = 4.11). Repeated-measures analysis of variance demonstrated significant differences (p < 0.001) in estimates of V[Combining Dot Above]O2max among Foster (44.1 ± 6.1), Bruce (47.1 ± 5.5), and our football (45.1 ± 5.8) equations. Foster and Bruce V[Combining Dot Above]O2max estimates were also significantly different from M-V[Combining Dot Above]O2max ((Equation is included in full-text article.)diff = -0.975 and 1.995, respectively, p < 0.001). V[Combining Dot Above]O2max of ASF athletes can be reasonably estimated by our football prediction equation using maximal treadmill time as the predictor.

The Omega-3 Index in National Collegiate Athletic Association Division I Collegiate Football Athletes.

CONTEXT: The essential omega-3 fatty acids (ω-3 FAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) exhibit vital biological roles and are critical for cardiovascular and neurologic health. Compared with the general population, football athletes may be at an increased risk of cardiovascular disease. Further, those same athletes are also exposed to repetitive head impacts, which may lead to long-term neurologic deficits. Both diets high in ω-3 FAs and supplementation with ω-3 FAs have been reported to reduce the risk of cardiovascular disease, and early evidence suggests a potential neuroprotective effect of supplementation. OBJECTIVE: To determine the (1) erythrocyte content of DHA and EPA, as measured by the Omega-3 Index, expressed as a percentage of total fatty acids, in National Collegiate Athletic Association Division I football athletes and (2) distribution across the Omega-3 Index risk zones established for cardiovascular disease: high risk, <4%; intermediate risk, 4% to 8%; and low risk, >8%. DESIGN: Cross-sectional descriptive study. SETTING: Multicenter trial. PATIENTS OR OTHER PARTICIPANTS: Deidentified data including complete erythrocyte fatty acid profile from the 2017-2018 season, age at time of testing, height, weight, and ethnicity were collected from 404 athletes. MAIN OUTCOME MEASURE(S): Omega-3 Index. RESULTS: About 34% of athletes (n = 138) had an Omega-3 Index considered high risk (<4%), and 66% (n = 266) had a risk considered intermediate (4%-8%). None had a low-risk Omega-3 Index. CONCLUSIONS: The Omega-3 Index is a simple, minimally invasive test of ω-3 FA status. Our data indicate that football athletes may be deficient in the ω-3 FAs DHA and EPA. The fact that no athlete had an Omega-3 Index associated with low risk suggests football athletes may be at increased risk for cardiovascular disease in later life.

Body Composition and Bone Mineral Density of Division 1 Collegiate Football Players: A Consortium of College Athlete Research Study.

Bosch, TA, Carbuhn, AF, Stanforth, PR, Oliver, JM, Keller, KA, and Dengel, DR. Body composition and bone mineral density of Division 1 collegiate football players: a consortium of college athlete research study. J Strength Cond Res 33(5): 1339-1346, 2019-The purpose of this study was to generate normative data for total and regional body composition in Division 1 collegiate football players using dual-energy x-ray absorptiometry (DXA) and examine positional differences in total and regional measurements. Data were used from the Consortium of College Athlete Research (C-CAR) group. Four hundred sixty-seven players were included in this study. Height, body mass, total and regional fat mass, lean mass, and bone mineral density were measured in each athlete in the preseason (June-August). Players were categorized by their offensive or defensive position for comparisons. Linemen tended to have the higher fat and lean mass measures (p ≤ 0.05 for all) compared with other positions. Positions that mirror each other (e.g. linemen) had similar body composition and body ratios. All positions were classified as overweight or obese based on body mass index (BMI) (>25 kg·m), yet other than offensive and defensive linemen, all positions had healthy percent body fat (13-20%) and low visceral fat mass (<500 g). The data presented here provide normative positional data for total and regional fat mass, lean mass, and bone density in Division 1 collegiate football players. Player position had a significant effect on body composition measures and is likely associated with on-field positional requirements. From a player's health perspective, although all positions had relatively high BMI values, most positions had relatively low body fat and visceral fat, which is important for the health of players during and after their playing career. The increased accuracy and reliability of DXA provides greater information, regarding positional differences in college football players compared with other methods.

Effects of Probiotic (Bifidobacterium longum 35624) Supplementation on Exercise Performance, Immune Modulation, and Cognitive Outlook in Division I Female Swimmers.

Our aim was to determine the effects of probiotic supplementation (Bifidobacterium longum 35624; 1 billion CFU·d-1) on exercise performance, immune modulation, and cognitive outlook in collegiate female athletes during six weeks of offseason training. Seventeen National Collegiate Athletic Association (NCAA) Division 1 collegiate female swimmers participated in this two-group matched, double-blind, placebo controlled design. Via stratified randomization, participants were assigned to probiotic (B. longum 35624; n = 8) or placebo (n = 9) groups. Pre, mid, and post-training, all participants completed exercise performance testing (aerobic/anaerobic swim time trials and force plate vertical jump) as well as provided serum (cytokine and gastrointestinal inflammatory markers) and salivary immunoglobulin A samples. Recovery-stress questionnaire for athletes (RESTQ-Sport) was administered at baseline and conclusion of each week. Data were analyzed by analysis of covariance (ANCOVA) by time point with the respective baseline values of each dependent variable being the covariate. No significant differences in exercise performance and biochemical markers were observed between groups following offseason training. Recovery-Stress Questionnaire for Athletes (RESTQ-sport) values in B. longum 35624 group had significantly higher (i.e., more desired; p < 0.05) values in sport recovery (weeks five and six) than placebo. Probiotic supplementation in collegiate female swimmers did not affect exercise performance or immune function throughout offseason training, but did indicate alterations in cognitive outlook.

Exercise attenuates the increase in plasma monounsaturated fatty acids and high-density lipoprotein cholesterol but not high-density lipoprotein 2b cholesterol caused by high-oleic ground beef in women.

We hypothesized that dietary monounsaturated fatty acids (MUFA) and exercise increase high-density lipoprotein cholesterol (HDL-C) by independent mechanisms, so there would be additive effects between a single, intensive session of exercise and high-MUFA ground beef on HDL-C and blood risk factors for cardiovascular disease. Seventeen postmenopausal women completed a 2-way crossover design in which they consumed five 114-g ground beef patties per week for two 6-week periods separated by a 4-week washout (habitual diet) period. The ground beef patties contained 21% total fat with either 9.97 (low-MUFA) or 12.72 (high-MUFA) g total MUFA. Blood was taken at entry, at the end of each 6-week diet period, after the 4-week washout period, and 24 hours after aerobic exercise sessions (75% VO2peak, 2.07 MJ). After the ground beef intervention, the high-MUFA ground beef increased plasma palmitoleic acid and oleic acid, low-density lipoprotein (LDL) particle density, HDL-C, and HDL2b-C (all P < .05), whereas the low-MUFA ground beef increased LDL density. After the washout (habitual diet) period, the single exercise session increased serum LDL cholesterol, HDL-C, and HDL2a and decreased TAG and oleic acid. After the low-MUFA ground beef diet, exercise increased LDL size and HDL density and decreased LDL density and very low-density lipoprotein cholesterol, but had no effect on HDL-C fractions. After the high-MUFA ground beef intervention, exercise decreased palmitioleic acid, oleic acid, HDL-C, and HDL2a-C, but not HDL2b-C. Contrary to our hypothesis, the effects of exercise and a high-MUFA diet were not additive; instead, exercise attenuated the effects of the high-MUFA ground beef on HDL-C and plasma MUFAs. The differential effects of high-MUFA ground beef and exercise on HDL2a-C and HDL2b-C indicate that diet and exercise affect HDL-C by different mechanisms.

VO2 prediction and cardiorespiratory responses during underwater treadmill exercise.

We compared cardiorespiratory responses to exercise on an underwater treadmill (UTM) and land treadmill (LTM) and derived an equation to estimate oxygen consumption (VO2) during UTM exercise. Fifty-five men and women completed one LTM and five UTM exercise sessions on separate days. The UTM sessions consisted of chest-deep immersion, with 0, 25, 50, 75, and 100% water-jet resistance. All session treadmill velocities increased every 3 min from 53.6 to 187.8 m x min(-1). Cardiorespiratory responses were similar between LTM and UTM when jet resistance for UTM was 50%. Using multiple regression analysis, weight-relative VO2 could be estimated as: VO2 (mLO2 c kg(-1) x min(-1)) = 0.19248 x height (cm) + 0.17422 x jet resistance (% max) + 0.14092 x velocity (m x min(-1)) -0.12794 x weight (kg)-27.82849, R2 = .82. Our data indicate that similar LTM and UTM cardiorespiratory responses are achievable, and we provide a reasonable estimate of UTM VO2.