Jeanne F. Nichols

Assessing Perceived Physical Environmental Variables that May Influence Physical Activity

The present study evaluated a measure of perceived physical environments that may influence physical activity. Forty-three self-report items were used to assess environmental variables at homes, in neighborhoods, or on frequently traveled routes. The presence of facilitators of (e.g., equipment, programs, attractive surroundings) and barriers to (e.g., high crime) physical activity was assessed. In 110 college students, test-retest reliabilities were .89 for the home equipment scale, .68 for the neighborhood scale, and .80 for the convenient facilities scale. Home equipment and convenient facilities scales were correlated with self-reported physical activity. In multiple regression analyses, the only significant association, after adjusting for neighborhood socioeconomic status, was home equipment with strength exercise. Further research is needed to identify other environmental characteristics that may influence physical activity.

Assessment of Physical Activity with the Computer Science and Applications, Inc., Accelerometer: Laboratory versus Field Validation

Abstract Our purpose was to compare the validity of the Computer Science and Applications, (CSA) Inc., accelerometer in laboratory and field settings and establish CSA count ranges for light, moderate, and vigorous physical activity. Validity was determined in 60 adults during treadmill exercise, using oxygen consumption (VO2) as the criterion measure, while 30 adults walked and jogged outdoors on a 400-m track. The relationship between CSA counts and VO2 was linear (R2 = .89 SEE = 3.72 ml. kg1. min1), as was the relationship between velocity and counts in the field (R2 = .89, SEE = 0.89 mi. hr1). However, significant differences were found (p < .05) between laboratory and field measures of CSA counts for light and vigorous intensity. We conclude that the CSA can be used to quantify walking and jogging outdoors on level ground; however, laboratory equations may not be appropriate for use in field settings, particularly for light and vigorous activity.

Validity, reliability, and calibration of the Tritrac accelerometer as a measure of physical activity.

PURPOSE The purposes of this study were to assess the validity and reliability of the Tritrac R3D accelerometer during treadmill walking and running and then to calibrate the instrument. METHODS The Tritrac was assessed on 60 young adults (23.4 +/- 2.9 yr) during treadmill walking and running at 3.2, 6.4, and 9.7 km x h(-1). The calibration was carried out by identifying ranges of Tritrac raw data (vector magnitude) values corresponding to light (2-3.9 MET), moderate (4-7 MET), and vigorous (>7 MET) physical activity. Energy expenditure (EE), measured by indirect calorimetry, served as the criterion measure. RESULTS Interinstrument intraclass reliability coefficients for Tritracs worn on the right and left hip ranged from 0.73-0.87, while intersession coefficients demonstrated high reliability for all speeds (R = 0.87-0.92). Paired t-tests comparing mean accelerometer counts at 6.4 km x h(-1), 0% grade (2647 +/- 456), and 6.4 km x h(-1), 5% grade (2635 +/- 435) demonstrated no significant difference (P > 0.05). Mean differences between EE measured by indirect calorimetry and that estimated by the Tritrac ranged from 0.0082 kcal x kg(-1) x min(-1) at 3.2 km x h(-1) to 0.0320 kcal x kg(-1) x min(-1) at 9.7 km x h(-1), with the Tritrac consistently overestimating EE during horizontal treadmill walking. The relationship between vector magnitude and EE across all speeds was highly linear (R2 = 0.90, SEE = 0.014 kcal x kg(-1) x min(-1)), with little overlap between light, moderate, and vigorous categories. The mean vector magnitudes at 2, 4, and 7 MET were 650, 1772, and 3455, respectively. CONCLUSIONS These data indicate that the Tritrac is highly reliable from day to day and is sensitive to changes in speed but not grade. Furthermore, the Tritrac accurately distinguishes various intensities of walking and jogging on level ground. With limitations, these cut-points can be used to categorize light, moderate, and vigorous physical activity and to estimate EE.

Efficacy of Heavy-Resistance Training for Active Women over Sixty: Muscular Strength, Body Composition, and Program Adherence

Objective: To determine the effects of resistance training on muscular strength, body composition (percent fat and lean tissue mass), and program adherence in active women over 60 years of age.

Self-report measures and scoring protocols affect prevalence estimates of meeting physical activity guidelines

PURPOSE Prevalence estimates of meeting the guidelines for physical activity based on various self-report measures were compared, and the effects of various scoring protocols on the estimates were evaluated. METHOD A sample of 575 university students aged 24.5 +/- 1.9 yr (56% women, 54% Euro-American) completed the Seven-Day Physical Activity Recall interview (PAR), Youth Risk Behavior Survey (YRBS), and National Health Interview Survey 1991 (NHIS). To determine the prevalence of meeting the ACSM (1990) fitness and the CDC/ACSM (1995) health-related guidelines, various scoring protocols were employed that closely approximated the recommendations. Protocols varied by whether frequency and duration or duration only were considered. For the health-related guidelines, scoring protocols also varied depending on the intensity of activities considered. RESULTS Depending on the scoring protocol and instrument used, the proportion meeting the fitness guidelines ranged from 32 to 59%. The NHIS, YRBS, and PAR resulted in significantly different proportions of those meeting the health-related guideline, ranging from 4 to 70%. CONCLUSION The type of measure as well as the scoring protocol affected prevalence estimates of meeting the physical activity guidelines. This study indicates the difficulty of comparing prevalence rates across studies using different measures.

Project GRAD: two-year outcomes of a randomized controlled physical activity intervention among young adults. Graduate Ready for Activity Daily.

INTRODUCTION Project Graduate Ready for Activity Daily evaluated a program to promote physical activity through the transition of university graduation in a randomized controlled trial. METHODS Three hundred thirty-eight university seniors participated in either a cognitive-behavioral intervention course or a knowledge-oriented general health course during the semester before graduation. Behaviorally oriented phone and mail follow-up was delivered to the intervention group for 18 months. Physical activity outcomes and mediating variables were assessed at baseline, 1 and 2 years (93% retention rate). RESULTS There were no significant intervention effects on physical activity outcomes at 2 years for either men or women. Experiential and behavioral processes of change were significantly improved for intervention women over 2 years. CONCLUSIONS Despite excellent participation in a theoretically based, well-attended intervention, few long-term effects on physical activity or its mediators were found. Additional research is needed to determine optimal interventions for physical activity and to validate or alter current behavior change theory.

Evaluation of a University Course to Promote Physical Activity: Project GRAD

Project GRAD (Graduate Ready for Activity Daily) evaluates a university course to promote physical activity. In a randomized study, 338 university seniors participated in either an intervention or control course for academic credit, and posttest data were collected on 321. The control course was knowledge-oriented. The intervention course taught behavior change skills in weekly lectures and peer-led labs. Physical activity was assessed with 7-Day Physical Activity Recall interviews. The intervention had no significant effects on men. Among women, the intervention increased total physical activity during leisure, strengthening exercises, and flexibility exercise. This university course had the intended effects of promoting healthful patterns of physical activity among women, but no effects were observed on men, who were more active than women at baseline.

Relationships among injury and disordered eating, menstrual dysfunction, and low bone mineral density in high school athletes: a prospective study.

CONTEXT Prior authors have reported associations among increased risk of injury and factors of the female athlete triad, as defined before the 2007 American College of Sports Medicine position stand, in collegiate and adult club sport populations. Little is known about this relationship in an adolescent competitive sports population. OBJECTIVE To examine the relationship among disordered eating, menstrual dysfunction, and low bone mineral density (BMD) and musculoskeletal injury among girls in high school sports. DESIGN Prospective cohort study. SETTING The sample consisted of 163 female athletes competing in 8 interscholastic sports in southern California during the 2003-2004 school year. Each participant was followed throughout her respective sport season for occurrence of musculoskeletal injuries. MAIN OUTCOME MEASURE(S) Data collected included daily injury reports, the Eating Disorder Examination Questionnaire that assessed disordered eating attitudes and behaviors, a dual-energy x-ray absorptiometry scan that measured BMD and lean tissue mass, anthropometric measurements, and a questionnaire on menstrual history and demographic characteristics. RESULTS Sixty-one athletes (37.4%) incurred 90 musculoskeletal injuries. In our BMD z score model of <or=-1 SD, a history of oligomenorrhea/amenorrhea during the past year and low BMD (z score <or=-1 SD) were associated with the occurrence of musculoskeletal injury during the interscholastic sport season. In our BMD z score model of <or=-2 SDs, disordered eating (Eating Disorder Examination Questionnaire score >or=4.0), a history of oligomenorrhea/amenorrhea during the past year, and a low BMD (z score <or=-2 SDs) were associated with musculoskeletal injury occurrence. CONCLUSIONS These findings indicate that disordered eating, oligomenorrhea/amenorrhea, and low BMD were associated with musculoskeletal injuries in these female high school athletes. Programs designed to identify and prevent disordered eating and menstrual dysfunction and to increase bone mass in athletes may help to reduce musculoskeletal injuries.

2014 female athlete triad coalition consensus statement on treatment and return to play of the female athlete triad.

The female athlete triad is a medical condition often observed in physically active girls and women and involves three components: 1) low energy availability with or without disordered eating, 2) menstrual dysfunction, and 3) low bone mineral density. Female athletes often present with one or more of the three triad components, and early intervention is essential to prevent its progression to serious end points that include clinical eating disorders, amenorrhea, and osteoporosis. This consensus statement presents a set of recommendations developed following the first (San Francisco, CA) and second (Indianapolis, IN) International Symposia on the Female Athlete Triad. This consensus statement was intended to provide clinical guidelines for physicians, athletic trainers, and other health care providers for the screening, diagnosis, and treatment of the female athlete triad and to provide clear recommendations for return to play. The expert panel has proposed a risk stratification point system that takes into account magnitude of risk to assist the physician in decision making regarding sport participation, clearance, and return to play. Guidelines are offered for clearance categories, management by a multidisciplinary team, and implementation of treatment contracts.

Higher Incidence of Bone Stress Injuries With Increasing Female Athlete Triad–Related Risk Factors: A Prospective Multisite Study of Exercising Girls and Women

Background: Identifying the risk factors associated with a bone stress injury (BSI), including stress reactions and stress fractures, may aid in targeting those at increased risk and in formulating prevention guidelines for exercising girls and women. Purpose: To evaluate the effect of single or combined risk factors as defined by the female athlete triad—a syndrome involving 3 interrelated spectrums consisting of energy availability, menstrual function, and bone mass—with the incidence of BSIs in a multicenter prospective sample of 4 cohorts of physically active girls and women. Study Design: Cohort study; Level of evidence, 3. Methods: At baseline, participants’ (N = 259; mean age, 18.1 ± 0.3 years) anthropometric characteristics, eating attitudes and behaviors, menstrual function, sports participation or exercise activity, and pathological weight control behaviors were assessed. Dual-energy x-ray absorptiometry (DXA) measured the bone mass of the whole body, total hip, femoral neck, lumbar spine, and body composition. Participants were followed prospectively for the occurrence of injuries; those injuries confirmed by a physician were recorded. Results: Twenty-eight participants (10.8%) incurred a BSI. Forty-six percent of those who had ≥12 h/wk of purposeful exercise, a bone mineral density (BMD) Z score <–1.0, and who exhibited 3 to 4 of the following: BMI <21.0 kg/m2, oligo- or amenorrhea, elevated dietary restraint, and/or participation in a leanness sport exercise/activity at baseline, incurred a BSI during the prospective study period. Single factors significantly (P < .05) associated with the development of a BSI included ≥12 h/wk of purposeful exercise (14.7%), BMI <21.0 kg/m2 (15.3%), and low bone mass (BMD Z score <–1.0; 21.0%). The strongest 2- and 3-variable combined risk factors were low BMD (Z score <–1.0) + ≥12 h/wk of exercise, with 29.7% incurring a BSI (odds ratio [OR], 5.1; 95% CI, 2.2-12.1), and ≥12 h/wk of exercise + leanness sport/activity + dietary restraint, with 46.2% incurring a BSI (OR, 8.7; 95% CI, 2.7-28.3). Conclusion: In the sample, which included female adolescents and young adults participating in competitive or recreational exercise activities, the risk of BSIs increased from approximately 15% to 20% for significant single risk factors to 30% to 50% for significant combined female athlete triad–related risk factor variables. These data support the notion that the cumulative risk for BSIs increases as the number of Triad-related risk factors accumulates.