Cold water immersion (CWI) is the most effective known cooling treatment against exercise-induced hyperthermia. However, sex differences related to body composition (i.e. body fat, muscle mass, surface area, etc.) may affect core cooling rates in hyperthermic males and females. Purpose. To determine sex related differences in core cooling rates during CWI after exercise-induced hyperthermia. Methods. Ten male (M) and nine female (F) participants matched for body surface area to mass ratio took part in this study. Participants exercised at 65% V˙O2max at an ambient temperature of 40°C until rectal temperature (Tre) increased to 39.5°C. Following exercise, subjects were immersed in a 2°C circulated water bath until Tre decreased to 37.5°C. Results. Females had a significantly greater core cooling rate compared to males. This was paralleled by a lower skin temperature and a shorter time to reach the exit criterion. Conclusion. We conclude that previously hyperthermic females have a 1.7 times greater Tre cooling rate compared to males. We attribute this difference to a smaller lean body mass (expressed by the body-surface-area-to-lean-body-mass ratio) in females compared to males.

Cold-induced shivering is characterized by two distinct muscle contraction patterns: continuous low-intensity shivering [at ∼1 to 5% of maximal voluntary contraction (MVC)] and bursts of high-intensity shivering (at 10 to 35% MVC) (Meigal, 2002, Haman et al., 2004). In this context, Haman et al. (2004) showed that carbohydrate (CHO) oxidation rate is directly related to burst shivering rate which increases the proportional recruitment of glycolitic type II fibers. Because most of these studies have been carried out in men, little is still know on the effects of hormonal fluctuations during the menstrual cycle on the dual shivering pattern and energy metabolism in women. Therefore, the purpose of this study was to quantify differences in muscle recruitment pattern and fuel selection in two phases of the menstrual cycle. Muscle recruitment in eight muscles and whole body fuel selection were monitored in women exposed to 120 min of cold exposure (5°C liquid-perfusion suit) during FP and LP. Results show that there is no difference in the onset of shivering, shivering intensity, burst duration and burst shivering rate between LP and FP during steady state shivering (in last 15 min). Similarly, during steady state shivering (T=105-120 min), absolute rates and relative contributions of metabolic fuels to total heat production did not differ between FP and LP. We conclude that hormonal fluctuations during the menstrual cycle do not affect muscle recruitment patterns or substrate utilization in the cold. Whether this important difference in fuel selection modifies muscle shivering activity and/or confers a survival advantage remains to be established.

This study incorporated the perspectives of twelve experienced physical education (PE) teachers to better understand the ways they learn, and what influences their choices regarding professional learning. By providing a Canadian perspective on a topic that has primarily been researched in the UK, this study addresses a current gap in the experienced PE teacher learning literature (Armour & Yelling, 2007; O'Sullivan, 2006). Using Illeris' (2007) workplace learning theory, the study provides a holistic understanding of teacher professional learning by equally acknowledging the individual and the environment. The data collected from three focus groups and twelve individual interviews indicated that the PE teachers learned in a variety of formal, nonformal and informal ways (Coombs, 1974). Moreover, the individual and the work environment influenced each teacher's professional learning. Finally, the participants continually engaged in informal learning to augment their formal and nonformal learning opportunities and they credited professional learning with helping them to develop as effective teachers.

Olympic weightlifting has been subject to rigorous academic and applied sporting research for over 40 years. Biomechanists have concerned themselves with Olympic weightlifting due to the complex coordination requirements coupled with high levels of full-body muscular activity. Motivated by Enoka's (1988) research on load- and skill-related changes; we used modern three-dimensional motion capture to assess selected mechanical characteristics of the snatch lift across varied lifting intensities. Our research variables included peak moment powers about the joints of the lower extremity, bilateral shoulder symmetry, and range of anterior-posterior system centre of mass (COM) movement as barbell load was varied across 80, 85, and 90% of each lifter's maximum. The five subjects were elite-level Olympic weightlifters (mean age 23 +/- 4.18 years, mean mass 77.6 +/- 5.81 kg). Multiple dependent t-tests (one for each joint pair) with Bonferroni corrections were applied between left and right peak powers to assess symmetry in the lower extremities. No significant differences were found, t(df =14) = 0.068, 0.038, and 0.039. Significance statistics wereall > p (alpha/n) = 0.0167 about the ankle, knee, and hip joint pairs, respectively. This confirmed assumptions of previous researchers that peak moment powers in elite-level lifters were symmetrical between joint pairs of the lower extremity. Exploiting the symmetry results, we simplified further analyses by considering only the left side of the body. Repeated-measures ANOVA revealed no significant differences in average peak moment power in three dimensions about the joints of the left lower extremity across barbell intensities. In the flexion extension plane of motion, left ankle F (2, 8) = 2.594, p = 0.135, knee F (2,8) = 0.133, p = 0.878, and hip F (2, 8) = 0.420, P = 0.671). Similar results followed for motion about the y and z axes of motion. Results indicated between 80-90% of maximal barbell load, no differences existed in average peak moment powers about the joints of the lower extremity. These results confirmed the findings of Enoka (1988) and showed lifters do not accommodated heavier barbell loads through increased peak moment powers in the lower extremities. Shoulder symmetry was assessed through graphical and numerical methods. All trials showed Pearson's correlations of r > 0.95, which indicated strong similarity between left and right shoulder trajectories. Bilateral shoulder position remained highly stable across barbell intensities, as participants did not modify shoulder symmetry across the tested intensity range. Range of anterior-posterior system COM movement showed no significant differences across barbell intensities (F (2, 4) = 0.765, P = 0.523). While the range of anterior-posterior system COM motion did not vary across barbell intensities, various motion trends were observed. The anterior-posterior range of system COM motion was quite small, but perturbations in system COM trajectory could be detrimental to subsequent lift phases as the barbell load approaches maximum. In conclusion, peak moment powers about the joints of lower extremities did not vary significantly across snatch lifts of 80-90% maximal capacity. Thus, training programs designed to improve athletic power through the use of weightlifting movements should not exceed the 80% limit for snatch based exercises. Statistical tests revealed no significant differences between average peak moment powers between left and right joint pairs of the lower extremities. The peak moment powers during the snatch lift were not asymmetrical. Our research demonstrated elite-level weightlifters exhibiting strong linear correlation in shoulder position across the 8090% range of barbell loads. System COM showed no significant variation in anterior-posterior range of motion across barbell intensities. This research confirmed the results previously established by Enoka (1988) regarding power response to load variation.

Background: The prevalence of childhood obesity has increased dramatically over the past decade, highlighting the necessity to determine its effects on metabolic profile. Research has shown that abdominal obesity is strongly linked to hyperinsulinemia, dyslipidemia, insulin resistance and type II diabetes, leading to an increased risk for the development of the metabolic syndrome. Currently, little is known about the factors that may predispose individuals to the development of this syndrome. Few studies have looked at the effect of resting metabolic rate on the development of the metabolic syndrome. The effect of body fat distribution on metabolic profile is also an important consideration that warrants further investigation. Objectives: 1) To compare the resting metabolic rate of obese adolescents, in the Healthy Eating, Aerobic and Resistance Training in Youth (HEARTY) trial, with the metabolic syndrome to those without the metabolic syndrome when matched for age, sex and BMI. A secondary objective was to compare the body fat distribution of adolescents with the metabolic syndrome to those with a healthy metabolic profile. 2) To explore the association between adipose tissue distribution (total, visceral, subcutaneous, deep subcutaneous and superficial subcutaneous adipose tissue) and metabolic risk factors (total, LDL-, and HDL- cholesterol, triglycerides, fasting insulin, fasting glucose, 2-hour glucose, HOMA-IR and blood pressure) of obese adolescents in the HEARTY study. Methods: 1) 41 obese adolescents with the metabolic syndrome, as assessed by the International Diabetes Federation criteria, were matched for BMI, age and sex with 41 metabolically healthy obese adolescents. Resting metabolic rate was acquired using indirect calorimetry. Body composition was quantified using Magnetic Resonance Imaging (MRI). 2) 105 participants were included in the analysis. Body composition variables were determined using MRI. Blood pressure, fasting plasma glucose, total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, insulin, and 2-hour glucose were measured. Insulin resistance was assessed using the homeostasis model of assessment score (HOMA-IR). Results: 1) Obese adolescents with the metabolic syndrome did not differ in resting metabolic rate compared to those without the syndrome. However, adolescents displaying an unhealthy metabolic profile did have greater visceral adipose tissue compared to those displaying a healthy metabolic profile. 2) Blood pressure, fasting insulin and HOMA-IR were significantly correlated with total adipose tissue, visceral adipose tissue, total subcutaneous adipose tissue and superficial subcutaneous adipose tissue. Triglyceride levels significantly correlated with total adipose tissue and visceral adipose tissue. However, on the multiple regression analysis visceral adipose tissue independently predicted total cholesterol, LDL cholesterol, 2-hour glucose and triglyceride levels, while deep subcutaneous adipose tissue independently predicted blood pressure. Conclusions: 1) Despite having an unhealthy metabolic profile, adolescents with the metabolic syndrome do not have an altered resting metabolic rate. However, the increased amount of visceral adipose tissue may play a part in the development of the syndrome. 2) Although all body fat depots are significantly correlated with metabolic risk factors, visceral adipose tissue remains more predictive of an adverse metabolic profile.

No description available.

This study compared bone mineral density of the radius, ulna, spine, and femur in healthy adults of varying activity levels. The sample included caucasian males (67) and females (82) ranging from 35 to 85 years. Males who were highly active in weight bearing activity had greater bone mineral density of the radius, ulna, femur neck and Ward's triangle of femur than those who were less active. Females who were highly active in high impact weight bearing activity and nonweight bearing activity had greater bone mineral density at the radius than females who were less active in these activities. Multiple regression revealed that weight bearing activity and age were fairly good predictors of radial bone mineral density in males aged 35-64 years, and high impact weight bearing activity and age were fairly good predictors of radial bone mineral density in females aged 35-49 years.

A descriptive study was conducted to explore diet and exercise patterns of 30 males 20-30 years old who exercised regularly. Data was collected from exercise facilities in Pima County using a three day food and physical activity record, a validated exercise attitude questionnaire, a demographic/exercise and health questionnaire, and a modified food frequency questionnaire. The group's breakdown of calories was 58% from carbohydrate, 25% from fat, 15% from protein, and 3% from alcohol. The mean values of the micronutrients measured for the group were 80% or higher compared to the RDAs. The average fruit and vegetable consumption for the group was low with only three servings per day. The Dietary Guidelines for Americans were followed in this population. Ninety percent of participants exercised an hour or more each day and there was no sign of exercise dependence in this population. It was concluded that this population has adequate diet and exercise patterns.

<p> There is an increasing amount of evidence indicating potentially devastating long-term effects of subconcussive impacts in the absence of clinical symptoms of concussion in high school football players.</p><p> <i>Purpose:</i> To determine whether subconcussive head impacts produce any immediate cognitive, postural, and physiological changes after athletic participation.</p><p> <i>Methods:</i> Fifty-nine interscholastic football (FB), soccer (SOC), and track (RUN) athletes provided baseline and post-participation data. Four cerebral acoustic response variables were examined using the Brain Acoustic Monitor (BAM) (Active Signal Technologies, Linthicum Heights, MD). Oculomotor function was assessed via the King-Devick (K-D) test. Balance was evaluated using a computerized version of the Balance Error Scoring System (BESS).</p><p> <i>Results:</i> Significant changes in left-brain ratio were observed in football players postgame (p = 0.023). Between-group analysis of baseline data for left- and right-brain divergence noted differences as well (FB vs. SOC, p = 0.012, p = 0.008, respectively; FB vs. RUN, p &lt; 0.001, p &lt; 0.001, respectively). There were no significant differences with either oculomotor or balance variables.</p><p> <i>Conclusions:</i> One game may not provide enough head impact exposure to elicit detectable changes with the utilized instrumentation. Unexpectedly, there were differences observed in football players' baseline BAM scores in the absence of significant differences in baseline and post-participation K-D test and BESS scores across all groups, possibly indicating that prior exposures to subconcussive impacts in this cohort of football players may be present.</p>

<p>Peer assessment is used by health care professionals as a way to share knowledge and evaluate the performance of colleagues. Peer assessment is used widely in medical education as a preparatory tool for students, but peer assessment research in athletic training education is lacking. Athletic trainers are healthcare providers with a similar skill-set to physicians, thus, athletic training education can benefit from the use of peer assessment. Athletic training educators need to research the use of peer assessment as an evaluation tool in order to better prepare students to practice as healthcare professionals. This study investigated the accuracy and reliability of undergraduate athletic training students in their ability to assess their peers. This quasi-experimental study used between-group and within-group designs to answer the research questions. Junior-level students, senior-level students, and their instructors were enrolled as participants. Each student group&rsquo;s ratings of clinical skills and professional behaviors were compared to instructor ratings to measure accuracy, and each student group&rsquo;s ratings were compared for reliability. Cohen&rsquo;s kappa coefficient measured inter-rater agreement for all statistical analyses. Both groups of students were accurate raters (<i>p</i> &lt; .05) of their peers on clinical skills, but only the senior-level students were accurate in rating professional behaviors. Both groups of students were reliable in rating their peers on about half of the clinical skills. The senior-level students were also reliable in evaluating professional behaviors, but the junior-level students were not. The data for this study showed high levels of observed agreement for most clinical skills, subscales and the professional behaviors, but some items had low Cohen&rsquo;s kappa values, most likely due to a known paradox that occurs with the kappa statistic. As the first study in athletic training education to use undergraduate students, live data collection, and rating of professional behaviors, the findings were promising for future research. Future research needs to include training in peer assessment, use of repeated measures, and comparison of instructor scores in order to better understand peer assessment in this population. Additionally, there is a need to establish consistent, quality measures in peer assessment research, including those used in athletic training education. </p>