Dawn P. Coe

Physical Fitness, Academic Achievement, and Socioeconomic Status in School-Aged Youth

BACKGROUND This study examined the association between physical fitness and academic achievement and determined the influence of socioeconomic status (SES) on the association between fitness and academic achievement in school-aged youth. METHODS Overall, 1,701 third-, sixth-, and ninth-grade students from 5 school districts participated in the assessments. Fitness was assessed using FITNESSGRAM (aerobic fitness, muscular strength, muscular endurance, flexibility, and body composition). Results were used to determine individual fitness scores. Academic achievement was measured by standardized tests for Math (all grades), English (all grades), and Social Studies (sixth and ninth grades only). The SES was determined using eligibility for free and reduced lunch program. RESULTS There were no significant differences between fitness groups for Math and English in third-grade students. Sixth- and ninth-grade students with high fitness scored significantly better on Math and Social Studies tests compared with less fit students. Lower SES students scored significantly worse on all tests. Muscular strength and muscular endurance were significantly associated with academic achievement in all grades. CONCLUSIONS Compared with all other variables, SES appears to have the strongest association with academic achievement. However, it also appears that high fitness levels are positively associated with academic achievement in school-aged youth.

Trends in Physical Activity and Sedentary Behaviors of United States Youth

BACKGROUND Increases in childhood and adolescent obesity are a growing concern in the United States (U.S.), and in most countries throughout the world. Declines in physical activity are often postulated to have contributed to the rise in obesity rates during the past 40 years. METHODS We searched for studies of trends in physical activity and sedentary behaviors of U.S. youth, using nontraditional data sources. Literature searches were conducted for active commuting, physical education, high-school sports, and outdoor play. In addition, trends in sedentary behaviors were examined. RESULTS Data from the Youth Risk Behavior Surveillance System (YRBSS) and other national surveys, as well as longitudinal studies in the transportation, education, electronic media, and recreation sectors showed evidence of changes in several indicators. Active commuting, high school physical education, and outdoor play (in 3- to 12-year-olds) declined over time, while sports participation in high school girls increased from 1971 to 2012. In addition, electronic entertainment and computer use increased during the first decade of the 21st century. CONCLUSIONS Technological and societal changes have impacted the types of physical activities performed by U.S. youth. These data are helpful in understanding the factors associated with the rise in obesity, and in proposing potential solutions.

Detecting indoor and outdoor environments using the ActiGraph GT3X+ light sensor in children.

INTRODUCTION Experts recommend children spend more time playing outdoors. The ambient light sensor of the ActiGraph GT3X+ provides lux measurements. A lux is the International Systems unit of illumination, equivalent to 1 lm·m. Few studies have established a lux threshold for determining whether a child is indoors or outdoors. PURPOSE This study aimed 1) to assess the reliability of the ActiGraph GT3X+ ambient light sensor, 2) to identify a lux threshold to accurately discriminate between indoor and outdoor activities in children, and 3) to test the accuracy of the lux threshold in a free-living environment. METHODS In part 1, a series of reliability tests were performed using 20 ActiGraph GT3X+ monitors under different environmental conditions. Cronbachs alpha was used to determine interinstrument reliability. In part 2, 18 children performed 11 different activities (five indoors and six outdoors) for 6 min each. The optimal threshold for detecting indoor/outdoor activity was determined using a receiver operator characteristic curve analysis. In part 3, 18 children at a preschool wore the monitor during a school day. Percent accuracy was determined for all conditions. RESULTS In part 1, the devices had Cronbachs alpha values of 0.992 and 1.000 for indoor and outdoor conditions, respectively, indicating high interinstrument reliability. In part 2, the optimal lux threshold was determined to be 240 lux (sensitivity = 0.92, specificity = 0.88, area under the curve = 0.96, 95% CI = 0.951-0.970). In part 3, results of the school-day validation demonstrated the monitor was 97.0% accurate for overall detection of indoor and outdoor conditions (outdoor = 88.9%, indoor = 99.1%). CONCLUSIONS The results demonstrate that an ActiGraph GT3X+ lux threshold of 240 can accurately assess indoor and outdoor conditions of preschool children in a free-living environment.

The ability of the PACER to elicit peak exercise response in youth [corrected].

PURPOSE A graded exercise test (GXT) is the standard laboratory method of determining peak aerobic fitness (V˙O2peak). The FITNESSGRAMs Progressive Aerobic Cardiovascular Endurance Run (PACER) test is commonly used to estimate the peak oxygen consumption in the youth in the field.The objective of this study is to compare the peak physiological variables and RPEpeak during a treadmill GXT and the PACER test in 10- to 15-yr-old youths. METHODS Participants (20 boys and 25 girls, 12.7 ± 1.7 yr) completed the PACER and treadmill GXT in a randomized order, separated by at least 24 h. HRpeak was measured via telemetry, V˙O2peak and RERpeak were measured using a portable metabolic system, and participants reported RPEpeak at the end of each test. RESULTS No significant differences were found between the GXT and PACER HRpeak (197 vs 197 beats·min), RERpeak (1.13 vs 1.12), V˙O2peak (45.0 vs 45.9 mL·kg·min), and RPEpeak (8.4 vs 8.3). The SE of the measurement between the GXT V˙O2peak and PACER V˙O2peak was 1.4 mL·kg·min. CONCLUSIONS It appears that the PACER elicits similar peak exercise responses compared with a treadmill GXT. The PACER can also be administered for fitness and functional capacity assessments in healthy and clinical populations.

Validity of the Bite Counter device in a controlled laboratory setting

UNLABELLED Body-borne sensors may be useful in assessing eating behaviors and have the potential to overcome some of the limitations of self-report instruments. The Bite Counter is a new commercial device, worn on the wrist that purports to track the number of bites taken per day. It contains a tri-axial accelerometer that detects an upward, arcing motion from the table to the mouth, known as a wrist roll. PURPOSE To examine the validity of the Bite Counter device for measuring bites in individuals while consuming various foods and beverages. METHODS 15 adults (23-58 years old) wore the device on the wrist of their dominant hand. They were presented with a meal consisting of foods/beverages, each consumed with different utensils: meat (knife and fork), side items (fork), soup (spoon), pizza (hands), can of soda (hands), and a smoothie (straw). Each food or drink was consumed by itself, in consecutive order. A researcher observed them through a one-way mirror and counted the number of bites taken. RESULTS The percentage of actual bites taken varied as follows: Meat (127%), side items (82.6%), soup (60.2%), pizza (87.3%), soda (81.7%), and smoothie (57.7%). The overall mean was 81.2% of bites taken. CONCLUSION The results indicate that the Bite Counter holds promise for being able to count the number of hand-to-mouth movements. In general, it underestimated hand-to-mouth movements, but some types of hand movements caused overestimation of bites. Future studies should be undertaken to improve the sensitivity and specificity of the Bite Counter device.

Physiologic Responses to Running with a Jogging Stroller

The purpose of this study was to assess the effect of running with a jogging stroller (JS) on oxygen consumption (VO2), heart rate (HR), and rating of perceived exertion (RPE). This study included 2 parts: Part 1 involved participants (N=15) running on an indoor track and Part 2 involved participants (N=12) running on a paved greenway. All participants completed 6, one-mile trials randomized over 2 visits: 3 were completed at a predetermined pace (160.8 m·min (- 1)) without a JS (NoJS), with 11.36 kg in the JS (JS1), and 22.72 kg in the JS (JS2) and 3 were self-paced and included NoJS, JS1, and JS2. VO2 and HR were measured using a portable metabolic system and telemetry. Repeated measures ANOVAs were used to determine differences among conditions. Part 1, there were no differences in VO2 across conditions, but HR and RPE were significantly higher (P<0.05) during the JS trials compared to the NoJS trials. Part 2, VO2 and RPE during JS trials were higher than NoJS trials (P<0.05). No significant differences were found in HR. The results indicate that it is feasible to run while pushing a JS with minimal increases in exertion compared to running without a JS.

Influence of Total Knee Arthroplasty on Gait Mechanics of the Replaced and Non-Replaced Limb During Stair Negotiation

This study compared biomechanics during stair ascent in replaced and non-replaced limbs of total knee arthroplasty (TKA) patients with control limbs of healthy participants. Thirteen TKA patients and fifteen controls performed stair ascent. Replaced and non-replaced knees of TKA patients were less flexed at contact compared to controls. The loading response peak knee extension moment was greater in control and non-replaced knees compared with replaced. The push-off peak knee abduction moment was elevated in replaced limbs compared to controls. Loading and push-off peak hip abduction moments were greater in replaced limbs compared to controls. The push-off peak hip abduction moment was greater in non-replaced limbs compared to controls. Future rehabilitation protocols should consider the replaced knee and also the non-replaced knee and surrounding joints.

Development of a Prediction Model to Predict VO2peak in Adolescent Girls Using the Bruce Protocol to Exhaustion

Purpose: The purpose of this study was to develop a prediction model based on a submaximal workload during the Bruce treadmill protocol to estimate peak oxygen consumption (VO2peak) in adolescent girls. Method: Adolescent girls (N = 116, Mage = 13.2 ± 2.0 years) performed a Bruce Treadmill Test to exhaustion. Expired respiratory gases and heart rate (HR) were collected and measured continuously via indirect calorimetry and telemetry. To be included in the analysis, each participant met 2 of 3 criteria: attain 95% of age-predicted HRpeak, respiratory exchange ratio>1.05, or plateau of VO2. VO2 and HR at Stage 1 and Stage 2 of the Bruce test were entered into a regression model to predict VO2peak. Results: A regression model, constructed using the predicted sum of squares statistic, was developed using VO2 (VO22) and HR (HR2) attained at the 2nd 3-min stage of the Bruce treadmill protocol: VO2peak = 46.77 − (0.2854155 × HR2)+(1.46732912 × VO22). Actual average ( ± SD) VO2peak was 36.2 ± 6.9 ml·kg− 1·min− 1 (range = 22.9–55.9). Predicted VO2peak was 36.2 ± 5.5 ml·kg− 1·min− 1 (range = 24.3–56.2). The correlation between actual and predicted VO2peak was r = .80, standard error of estimate = 4.2 ml·kg− 1·min− 1, with no bias relative to participant aerobic fitness. Conclusion: Based on this model, the VO2peak of healthy adolescent girls can be predicted within 4.2 ml·kg− 1·min− 1 using submaximal Bruce data.

Postprandial Walking Reduces Glucose Levels in Women with Gestational Diabetes Mellitus

The purpose of this study was to investigate blood glucose changes, as measured by a continuous glucose monitoring system, that occur in women with gestational diabetes mellitus (GDM) following an acute bout of moderate-intensity walking after consuming a high-carbohydrate/low-fat meal. This study found that moderate-intensity walking induced greater postprandial glucose control compared with sedentary activity and it appears that moderate-intensity activity may be used to reduce postprandial glucose levels in women with GDM.

Higher Education and Community Engagement

Our path through graduate school was incredibly similar. First, we earned Masters degrees from Central Michigan University in exercise science. During our experiences as graduate assistants in Mount Pleasant, Michigan we worked on similar research projects, learned from the same advisors, and taught the same classes.