This research examined the direction of causal flow between global and specific dimensions of self-concept. Although the multidimensionality of self-concept has been strongly supported in the literature, the hierarchical nature of self-concept has not been established. With the use of structural equation modeling, the hierarchical nature of self-concept was tested using the Physical Self-Perception Profile (PSPP) model both with and without global self-esteem included. Adolescent girls (N = 618) completed the PSPP and Harter’s global self-esteem scale during class time in Grade 9 and a year later in Grade 10. When horizontal effects were included in the self-concept models across age, there was little support for either top-down or bottom-up effects. This contrasted with the results found when the analysis was conducted within each time period separately. This research provides further evidence against the hierarchical model of self-concept and highlights the importance of examining the hierarchical nature of self-concept over time.
Kent C. Kowalski, Peter R.E. Crocker, Nanette P. Kowalski, Karen E. Chad and M. Louise Humbert
Darren G. Candow, Philip D. Chilibeck, Karen E. Chad, Murray J. Chrusch, K. Shawn Davison and Darren G. Burke
The authors previously found that creatine (Cr) combined with 12 weeks of resistance training enhanced muscle strength and endurance and lean tissue mass (LTM) in older men. Their purpose in this study was to assess these variables with cessation of Cr combined with 12 weeks of reduced training (33% lower volume) in a subgroup of these men (n = 8, 73 years old) compared with 5 men (69 years old) who did not receive Cr. Strength (1-repetition maximum [1-RM]), endurance (maximum number of repetitions over 3 sets at 70–80% 1-RM), and LTM (dual-energy X-ray absorptiometry) were assessed before and after 12 weeks of Cr cessation combined with reduced-volume training. No changes in strength or LTM occurred. Muscle endurance was significantly reduced (7–21%; p < .05), with the rate of change similar between groups. Withdrawal from Cr had no effect on the rate of strength, endurance, and loss of lean tissue mass with 12 weeks of reduced-volume training.
Mark W. Bruner, Karen E. Chad, Jodie A. Beattie-Flath, M. Louise Humbert, Tanya C. Verrall, Lan Vu and Nazeem Muhajarine
This study monitored the physical activity behavior of adolescent students over a ten month school year. Physical activity was assessed at two month intervals using selfreport and objective (Actical accelerometers) measures. Self-report results (n = 547) indicated a decline in physical activity throughout the school year for all grades and genders. The decline was attributed largely to a decrease in organized activity participation. Objective physical activity results (n = 40) revealed a significant decline in activity in the latter half of the school year (February to June). Declining physical activity was attributed to a decrease in vigorous activity which was consistent across grade and gender. Collectively, the results highlight the importance of promoting consistent opportunities for adolescents to be active throughout the school year.
Koren L. Fisher, Bruce A. Reeder, Elizabeth L. Harrison, Brenda G. Bruner, Nigel L. Ashworth, Punam Pahwa, Nazmi Sari, M. Suzanne Sheppard, Christopher A. Shields and Karen E. Chad
Objective : To assess the maintenance of physical activity (PA) and health gains among participants in a class-based (CB) or home-based (HB) PA intervention over a 12-month study period. Methods : A total of 172 adults aged 50 years and older were randomly allocated to either a CB or an HB intervention, each involving an intensive 3-month phase with a 9-month follow-up period. Measures at baseline, 3, 6, and 12 months included self-reported PA and health, body mass index, waist circumference (WC), blood pressure, cardiovascular endurance (6-min walk test), physical function, and functional fitness (senior fitness test). Outcomes were analyzed using generalized estimating equations. Results : Maximum improvement was typically observed at 3 or 6 months followed by a modest diminution, with no differences between groups. For body mass index, waist circumference, 6-min walk test, and senior fitness test, there was progressive improvement through the study period. Greater improvement was seen in the CB group compared with the HB group on three items on the senior fitness test (lower body strength and endurance [29% vs. 21%, p < .01], lower body flexibility [2.8 cm vs. 0.4 cm, p < .05], and dynamic agility [14% vs. 7%, p < .05]). Conclusion : The interventions were largely comparable; thus, availability, preferences, and cost may better guide program choice.
Koren L. Fisher, Elizabeth L. Harrison, Brenda G. Bruner, Joshua A. Lawson, Bruce A. Reeder, Nigel L. Ashworth, M. Suzanne Sheppard and Karen E. Chad
The purpose of this study was to explore cross-sectional relationships between self-reported physical activity (PA) and personal, social, and environmental factors in community-dwelling adults aged 50 years and older. Accounting for clustering by neighborhood, generalized estimating equations were used to examine associations between selected correlates and the Physical Activity Scale for the Elderly (PASE) score while adjusting for confounders. Data for 601 participants were analyzed: 79% female, 37% married, mean age 76.8 (± 8.7) years, mean PASE score 112.6 (± 64.8). Age, living in seniors’ housing, using nursing/home care services, receiving encouragement to be active, and having benches available in the neighborhood were inversely associated with PASE. Self-efficacy, SF-12 score, PA barriers, social support, and the presence of trails showed positive associations. Several personal, social, and environmental factors associated with PA were identified. The inverse association between PA and living in seniors’ housing units should be considered when developing PA programs for older adults.
Bruce A. Reeder, Karen E. Chad, Elizabeth L. Harrison, Nigel L. Ashworth, M. Suzanne Sheppard, Koren L. Fisher, Brenda G. Bruner, Brian G. Quinn, Punam Pahwa and M. Alomgir Hossain
The study aimed to compare the effectiveness of a class-based (CB) and home-based (HB) exercise program for older adults with chronic health conditions.
172 sedentary older adults with overweight or obesity, type 2 diabetes, hypertension, dyslipidemia, or osteoarthritis were enrolled in a randomized controlled trial with a 3-month follow-up.
A significant increase was seen in the CB group in the Physical Activity Scale for the Elderly (PASE) scores and SF-12 Physical and Mental Health scores. In both groups, significant increases were seen in 6-minute walk distance, Physical Performance Test (PPT), and Functional Fitness Test (FFT), and significant reductions were seen in systolic and diastolic blood pressure but not body mass index or waist circumference. Except for a greater increment in the FFT in the CB group, the degree of improvement was not significantly different between the 2 groups.
After a 3-month intervention, both the CB and HB program produced comparable significant improvements in outcome measures.