The Effect of a Commercially Available Caffeine Based Dietary Supplement on 40-Kilometer Time Trial Performance

Purpose: To determine wheather ot not the nutritional supplement PreRace containing L-Taurine, Citrulline Malate, Quercetin, DiMethyl Amino Ethanol, Caffeine, Metabromine, Catechin, and Malic acid will improve performance in an indoor 40 Kilometer cycling time trial.Methods: Seven male cyclists ages 21-58 participated in a placebo-controlled investigation which consisted of two trials in which they consumed either the supplement PreRace or aloe vera juice. In each of the trials the placebo or supplement was mixed with a sports beverage. Subjects performed a 40 kilometer time trial and measurements of oxygen consumption and lactate were taken every 15 minutes as well as 3 kilometers from the end.Results: Treatment effects were observed for average work, average watts, average velocity, oxygen consumption, heart rate, RPE, lactate, percentage of lactate threshold watts, and percentage of VO2max. No significant difference was observed in time to complete trials even though the experimental group finished an average of 3 minutes and 17 seconds faster.Conclusion: Ingestion of the supplement in this study results in effects that may result in an improvement in performance. A larger study is needed to determine if these results are reproducible to a statistically significant leve

Greater Polar Moment of Inertia at the Tibia in Athletes Who Develop Stress Fractures

Background: Several previous investigations have determined potential risk factors for stress fractures in athletes and military personnel. Purpose: To determine factors associated with the development of stress fractures in female athletes. Study Design: Case-control study; Level of evidence, 3. Methods: A total of 88 female athletes (cross-country, n ¼ 29; soccer, n ¼ 15; swimming, n ¼ 9; track and field, n ¼ 14; volleyball, n ¼ 12; and basketball, n ¼ 9) aged 18 to 24 years were recruited to participate in a longitudinal bone study and had their left distal tibia at the 4%, 20%, and 66% sites scanned by peripheral quantitative computed tomography (pQCT). Patients included 23 athletes who developed stress fractures during the following year (cases). Whole body, hip, and spine scans were obtained using dual-energy x-ray absorptiometry (DXA). Analysis of covariance was used to determine differences in bone parameters between cases and controls after adjusting for height, lower leg length, lean mass, fat mass, and sport. Results: No differences were observed between cases and controls in any of the DXA measurements. Cases had significantly greater unadjusted trabecular bone mineral content (BMC), greater polar moment of inertia (PMI) at the 20% site, and greater cortical BMC at the 66% site; however, after adjusting for covariates, the differences became nonsignificant. When analyses were repeated using all individuals who had ever had a stress fracture as cases (n ¼ 31) and after controlling for covariates, periosteal circumference was greater in the cases than the controls (71.1 ± 0.7 vs 69.4 ± 0.5 mm, respectively; P ¼ .04). Conclusion: A history of stress fractures is associated with larger bones. These findings are important because larger bones were previously reported to be protective against fractures and stress fractures, but study findings indicate that may not always be true. One explanation could be that individuals who sustain stress fractures have greater loading that results in greater periosteal circumference but also results in the development of stress fractures

Variation in Cortical Density Within the Cortical Shell of Individuals Across a Range in Densities and Ages

OBJECTIVES: The purpose of this study was to determine variability in cortical volumetric bone density (vBMD) from a single slice tibia image over a range of vBMD readings and ages. METHODS: Males and females (N=80; aged 6-80) were randomly selected from a previous study. Cortical vBMD at the anterior, posterior, medial, and lateral regions as well as the endocortical, mid-cortical, and pericortical regions of the cortical shell were determined using pQCT. RESULTS: Mean anterior ROI cortical vBMD (1111±11 mg/cm(3)) was lower than the posterior and lateral ROIs (1169±7 mg/cm(3) and 1151±9 mg/cm(3), respectively), (p CONCLUSIONS: Variability in cortical vBMD was higher among young individuals and those with lower overall cortical vBMD, while lowest in older individuals and men. The anterior ROI had lower mean cortical vBMD than posterior or lateral regions, and endocortical vBMD was lower than the mid- and pericortical regions

Feasibility, Compliance, and Efficacy of a Randomized Controlled Trial Using Vibration in Pre-pubertal Children

Objective: Interventions utilizing vibration may increase bone mass and size which may reduce forearm fractures in children. This randomized controlled pilot trial tested the feasibility, compliance and efficacy of forearm loading regimes in an after-school program in pre-pubertal children aged 6-10 years. Methods: A 12-week randomized controlled trial incorporated high (HMMS; N=10) and low (LMMS; N=10) magnitude mechanical stimulation vibration, floor exercises (N=9), and controls (N=10). Radial bone measures by DXA and pQCT were compared at the end of intervention (12-weeks) and 4-months post-intervention (4- months post). Results: Percent changes were significantly greater in floor vs. control for ultra-distal areal BMD by DXA at 12- weeks (1%[-2,5] vs.-5%[-8,-2] respectively, p=0.02) and 4-months post (5%[1,8] vs -2%[-5,2], p=0.03) and in HMMS vs. controls for trabecular vBMD by pQCT at 12-weeks (4%[0, 8], vs. -8% [-14, -2], p=0.02). Children exposed to HMMS showed positive changes in cortical BMC, area, and cortical vBMD after 12 weeks that remained 4 months post-intervention. Children exposed to floor exercise showed positive changes in cortical BMC, area, and periosteal circumference 4-months post-intervention. Controls had decreased trabecular BMD, but increased bone area and periosteal circumference. Conclusions: Exposure to floor exercise and HMMS increased trabecular aBMD and vBMD in the radius

Estimation of Length or Height in Infants and Young Children Using Ulnar and Lower Leg Length with Dual-energy X-ray Absorptiometry Validation

AIM: We compared the accuracy and reproducibility of using ulnar and lower leg length measurements to predict length and height in infants and children aged 0 to 6 years. METHOD: Length/height and ulnar and lower leg length were measured in 352 healthy preterm and term-born children (167 males, 185 females) (Mean age= 2.6±1.6 years). Ulna length was measured as the distance between the proximal olecranon process and the distal styloid process of the ulna. Tibia length was measured as the distance from the proximal aspect of the medial condyle and the most distal aspect of the medial malleolus of the tibia using a segmometer. Length measurements were taken using an infant length board in children less than 24 months of age, whereas a portable stadiometer was used to measure height in older children. Equations were developed using ulnar and lower leg length and age. Intra- and inter-examiner variability (n=167) was calculated, and dual-energy X-ray absorptiometry scans (n=126) were used to determine accuracy of limb lengths. RESULTS: Ulnar and lower leg length explained over 95% of the variability in length/height in term infants and children, but less in preterm infants (R(2) =0.80-0.87). In preterm infants, the limits of agreement (LOA) for males were -2.44 to 2.44cm and -2.88 to 2.88cm for the ulna and lower leg respectively, whereas the LOA for females were -1.90 to 1.90cm and -1.87 to 1.87cm respectively. In older children, the LOA for males were -5.53 to 4.48cm and -5.59 to 4.62cm for the ulna and lower leg respectively, whereas the LOA for females were -5.57 to 5.01cm and -6.02 to 5.02cm respectively. Intra- and inter-examiner variability was low for all measurements in both sexes and age groups. INTERPRETATION: Length and height measurements using infant length board or stadiometer are reproducible. Because of the wide limits of agreement, estimation of length and height in children using ulnar and lower leg length is not an acceptable alternative to traditional methods

Neuromuscular Performance Changes Throughout the Menstrual Cycle in Physically Active Females

OBJECTIVES: To determine changes in neuromuscular performance throughout the menstrual cycle in females aged 18-25. METHODS: Fifty physically active college females (25 on oral contraceptives (OC)) were recruited to participate. Data collection visits coincided with early-follicular (Fp), ovulatory (Op), and the mid-luteal (Lp) phases. Isokinetic peak torque at the knee (IPT) was measured at 60°/sec, 180°/sec, and 300°/sec. Grip force was measured using a handheld dynamometer. Plasma estradiol and progesterone confirmed menstrual cycle and serum relaxin was screened as a potential covariate. RESULTS: Grip strength was lower during Fp (30.1±0.7kg) than during Op (31.5±0.7 kg, p=0.003) and Lp (32.6±0.7 kg, p CONCLUSIONS: Results indicate that muscular performance is diminished during Fp and the lack of group-by-phase interaction indicates that this effect is not hormone-related. These data indicate that females may be at a greater risk of injury due to decreased strength during Fp than other phases of their cycle

South Dakota Pregnancy Survey 2016 Data Report

The South Dakota Department of Health, in conjunction with the EA Martin Program at South Dakota State University, conducted a 2016 Pregnancy Risk Assessment Monitoring System (PRAMS)-like surveillance project. The 2016 South Dakota PRAMS-like survey was a statewide population-based survey based on a stratified random sample of women who gave birth to a live-born infant, thereby allowing rates to be estimated for South Dakota mothers giving birth in 2016. The topics included in this survey were selected to enhance our understanding of maternal attitudes and behaviors around the time of pregnancy and the weighted response rate was 67.6%

Resistant Starch Type 4-enriched Diet Lowered Blood Cholesterols and Improved Body Composition in a Double Blind Controlled Cross-over Intervention

A metabolic health crisis is evident as cardiovascular diseases (CVD) remain the leading cause of mortality in the United States. Effects of resistant starch type 4 (RS4), a prebiotic fiber, in comprehensive management of metabolic syndrome (MetS) remain unknown. This study examined the effects of a blinded exchange of RS4-enriched flour (30% v/v) with regular/control flour (CF) diet on multiple MetS comorbidities. In a double blind (participants-investigators), placebo-controlled, cluster cross-over intervention (n = 86, age≥18, 2-12 week interventions, 2-week washout) in the United States, individuals were classified as having MetS (With-MetS) or not (No-MetS) following International Diabetes Federation (IDF)-criteria. RS4 consumption compared with CF resulted in 7.2% (p = 0.002) lower mean total cholesterol, 5.5% (p = 0.04) lower non-HDL, and a 12.8% (p \u3c 0.001) lower HDL cholesterol in the With-MetS group. No-MetS individuals had a 2.6% (p = 0.02) smaller waist circumference and 1.5% (p = 0.03) lower percent body fat following RS4 intervention compared to CF. A small but significant 1% increase in fat-free mass was observed in all participants combined (p = 0.02). No significant effect of RS4 was observed for glycemic variables and blood pressures. RS4 consumption improved dyslipidemia and body composition. Incorporation of RS4 in routine diets could offer an effective strategy for public cardio-metabolic health promotion

Rural vs. Non-rural Differences and Longitudinal Bone Changes by DXA and pQCT in Men Aged 20-66 Years: A Population-Based Study

The purpose of this research was to determine whether there were differences in estimated means and rates of change in BMC, bone area, BMD and measures of bone geometry among men (n=544) from three distinct populations (Hutterite [rural], rural non-Hutterite, non-rural), and whether activity levels or calcium intake explain these population differences. Men were enrolled in the South Dakota Rural Bone Health Study and followed for 7.5 years to estimate means and rates of change in bone mass, density, size and geometry. Femoral neck (FN) and spine measurements were obtained every 18 months by DXA and distal radius (4% and 20%) measurements by pQCT. Activity measurements and calcium intake were obtained quarterly for the first 3 years and at 54, 72, and 90 months. Rural men had greater percent time in moderate plus vigorous activity (mean ± SD: 22 ± 10 vs. 15 ± 8%,