Robert W. Motl

Measuring enjoyment of physical activity in adolescent girls

BACKGROUND Enjoyment has been implicated as a determinant of physical activity among youth, but advances in understanding its importance have been limited by the use of measures that were not adequately validated. The present study examined: (1) the factorial validity of the Physical Activity Enjoyment Scale (PACES), and (2) the construct validity of PACES scores. METHODS Adolescent girls (N=1797), who were randomly assigned to calibration (n=899) and cross-validation (n=898) samples, completed the PACES and measures of factors influencing enjoyment of physical education, physical activity, and sport involvement. The factorial validity of the PACES and the measure of factors influencing enjoyment of physical education was tested using exploratory and confirmatory factor analysis. The hypothesized relationships among the measures were tested using structural equation modeling. RESULTS Unidimensional models fit the PACES and the measure of factors influencing enjoyment of physical education in the calibration and cross-validation samples. The hypothesized relationships between the PACES and the measures of factors influencing enjoyment of physical education, physical activity, and sport involvement were supported in the entire sample, were similar in African-American and Caucasian girls, and were independent of physical fitness. CONCLUSIONS Evidence of factorial validity and convergent evidence for construct validity indicate that the PACES is a valid measure of physical activity enjoyment among adolescent girls, suitable for use as a mediator variable in interventions designed to increase physical activity.

Physical activity and multiple sclerosis: a meta-analysis

Using meta-analytic procedures, this study involved a quantitative synthesis of the difference in physical activity among individuals with multiple sclerosis (MS) compared with nondiseased and diseased populations and then examined factors (i.e., moderators) that explain variation in the overall difference in physical activity. We searched MEDLINE, PsycINFO and Current Contents Plus using the key words physical activity, exercise and physical fitness in conjunction with multiple sclerosis; conducted a manual search of bibliographies of the retrieved papers; and contacted study authors about additional studies. Overall, 53 effects were retrieved from 13 studies with 2360 MS participants and yielded a weighted mean effect size (ES) of -0.60 (95% CI= -0.44,-0.77). The weighted mean ES was heterogenous, Q=1164.11, df=52, p<0.0001. There were larger effects with objective versus self-report measures of physical activity, nondiseased versus diseased populations and primary progressive versus relapsing-remitting MS. The cumulative evidence suggests that individuals with MS are less physically active than nondiseased, but not diseased, populations.

Enjoyment mediates effects of a school-based physical-activity intervention.

PURPOSE The study evaluated whether targeted changes in factors influencing enjoyment of physical education (PE), physical activity enjoyment, and self-efficacy beliefs about participating in physical activity mediated the effect of the Lifestyle Education for Activity Program (LEAP) intervention on participation in physical activity. METHODS High schools (N=24) paired on enrollment size, racial composition, urban or rural location, and class structure were randomized into control (N=12) or experimental (N=12) groups. Of the 4044 girls enrolled and eligible, 2087 (51.6%) participated in the measurement component of the study. There were 1038 girls in the control group and 1049 girls in the experimental group. INTERVENTION LEAP was a comprehensive school-based intervention emphasizing changes in instruction and school environment designed to increase physical activity among black and white adolescent girls. It was organized according to the Coordinated School Health Program and included a PE component with core objectives of promoting enjoyment of PE, physical activity enjoyment, and self-efficacy. RESULTS Latent variable structural equation modeling indicated that: 1) the intervention had direct, positive effects on physical activity and factors influencing enjoyment of PE, which subsequently explained the effects of increased physical activity enjoyment and self-efficacy on increased physical activity; and 2) an additional, indirect effect of physical activity enjoyment on physical activity operated by an influence on self-efficacy. CONCLUSIONS Increases in enjoyment partially mediated the positive effect of the LEAP intervention. To our knowledge, we have provided the first experimental evidence from a randomized controlled trial linking increased enjoyment with increased physical activity among black and white adolescent girls.

Effect of exercise training on quality of life in multiple sclerosis: a meta-analysis.

Using meta-analytic procedures, this study examined the overall effect of exercise training interventions on quality of life (QOL) among individuals with multiple sclerosis (MS). We searched MEDLINE, PSYCHINFO and CURRENT CONTENTS PLUS for the period of 1960 to November 2006 using the key words exercise, physical activity and physical fitness in conjunction with QOL and MS. We further conducted a manual search of bibliographies of the retrieved papers as well as literature reviews and contacted study authors about additional studies. Twenty-five journal articles were located and reviewed, and only 13 provided enough data to compute effect sizes expressed as Cohens d. One hundred and nine effect sizes were retrieved from the 13 studies with 484 MS participants and yielded a weighted mean effect size of g = 0.23 (95% CI = 0.15, 0.31). There were larger effects associated with MS-specific measures of QOL and fatigue as an index of QOL. The nature of the exercise stimulus further influenced the magnitude of the mean effect size. The cumulative evidence supports that exercise training is associated with a small improvement in QOL among individuals with MS. Multiple Sclerosis 2008; 14: 129—135. http://msj.sagepub.com

Effect of Exercise Training on Walking Mobility in Multiple Sclerosis: A Meta-Analysis

Objective. The study used meta-analytic procedures to examine the overall effect of exercise training interventions on walking mobility among individuals with multiple sclerosis. Methods. A search was conducted for published exercise training studies from 1960 to November 2007 using MEDLINE, PsychINFO, CINAHL, and Current Contents Plus. Studies were selected if they measured walking mobility, using instruments identified as acceptable walking mobility constructs and outcome measures for individuals with neurologic disorders, before and after an intervention that included exercise training. Results. Forty-two published articles were located and reviewed, and 22 provided enough data to compute effect sizes expressed as Cohens d. Sixty-six effect sizes were retrieved from the 22 publications with 600 multiple sclerosis participants and yielded a weighted mean effect size of g = 0.19 (95% confidence interval, 0.09-0.28). There were larger effects associated with supervised exercise training ( g = 0.32), exercise programs that were less than 3 months in duration (g = 0.28), and mixed samples of relapsing-remitting and progressive multiple sclerosis (g = 0.52). Conclusions. The cumulative evidence supports that exercise training is associated with a small improvement in walking mobility among individuals with multiple sclerosis.

Effects of Exercise Training on Fitness, Mobility, Fatigue, and Health-Related Quality of Life Among Adults With Multiple Sclerosis: A Systematic Review to Inform Guideline Development

OBJECTIVE To conduct a systematic review of evidence surrounding the effects of exercise training on physical fitness, mobility, fatigue, and health-related quality of life in adults with multiple sclerosis (MS). DATA SOURCES The databases included EMBASE, 1980 to 2011 (wk 12); Ovid MEDLINE and Ovid OLDMEDLINE, 1947 to March (wk 3) 2011; PsycINFO, 1967 to March (wk 4) 2011; CINAHL all-inclusive; SPORTDiscus all-inclusive; Cochrane Library all-inclusive; and Physiotherapy Evidence Database all-inclusive. STUDY SELECTION The review was limited to English-language studies (published before December 2011) of people with MS that evaluated the effects of exercise training on outcomes of physical fitness, mobility, fatigue, and/or health-related quality of life. DATA EXTRACTION One research assistant extracted data and rated study quality. A second research assistant verified the extraction and quality assessment. DATA SYNTHESIS From the 4362 studies identified, 54 studies were included in the review. The extracted data were analyzed using a descriptive approach. There was strong evidence that exercise performed 2 times per week at a moderate intensity increases aerobic capacity and muscular strength. The evidence was not consistent regarding the effects of exercise training on other outcomes. CONCLUSIONS Among those with mild to moderate disability from MS, there is sufficient evidence that exercise training is effective for improving both aerobic capacity and muscular strength. Exercise may improve mobility, fatigue, and health-related quality of life.

Physical activity and quality of life in multiple sclerosis: intermediary roles of disability, fatigue, mood, pain, self-efficacy and social support.

Physical activity has been associated with a small improvement in quality of life (QOL) among those with multiple sclerosis (MS). This relationship may be indirect and operate through factors such as disability, fatigue, mood, pain, self-efficacy and social support. The present study examined variables that might account for the relationship between physical activity and QOL in a sample (N = 292) of individuals with a definite diagnosis of MS. The participants wore an accelerometer for 7 days and then completed self-report measures of physical activity, QOL, disability, fatigue, mood, pain, self-efficacy and social support. The data were analysed using covariance modelling in Mplus 3.0. The model provided an excellent fit for the data (χ 2 = 51.33, df = 18, p < 0.001, standardised root mean squared residual = 0.03, comparative fit index = 0.98). Those who were more physically active reported lower levels of disability (γ = −0.50), depression (γ = −0.31), fatigue (γ = −0.46) and pain (γ = −0.19) and higher levels of social support (γ = 0.20), self-efficacy for managing MS (γ = 0.41), and self-efficacy for regular physical activity (γ = 0.49). In turn, those who reported lower levels of depression (β = −0.37), anxiety (β = −0.15), fatigue (β = −0.16) and pain (β = −0.08) and higher levels of social support (β = 0.26) and self-efficacy for controlling MS (β = 0.17) reported higher levels of QOL. The observed pattern of relationships supports the possibility that physical activity is indirectly associated with improved QOL in individuals with MS via depression, fatigue, pain, social support and self-efficacy for managing MS.

Further Investigating Method Effects Associated With Negatively Worded Items on Self-Report Surveys

This article used multitrait-multimethod methodology and covariance modeling for an investigation of the presence and correlates of method effects associated with negatively worded items on the Rosenberg Self-Esteem (RSE) scale (Rosenberg, 1989) using a sample of 757 adults. Results showed that method effects associated with negative item phrasing on the RSE scale were present. Method effects associated with negative item wording were similarly observed with the Social Physique Anxiety Scale (SPAS; Hart, Leary, & Rejeski, 1989) and method effects were present and significantly correlated in analyses that included both the RSE scale and SPAS simultaneously. Path analysis modeling that incorporated personality measures identified factors that correlated with the presence of method effects. These findings further suggest that method effects associated with negatively worded items may be considered a response style.

Physical Activity and Cognitive Function in a Cross-Section of Younger and Older Community-Dwelling Individuals

Previous reports have indicated a small, positive relationship between physical activity and cognition. However, the majority of research has focused on older adults, with few studies examining this relationship during earlier periods of the life span. This study examined the relationship of physical activity to cognition in a cross-section of 241 community-dwelling individuals 15-71 years of age with a task requiring variable amounts of executive control. Data were analyzed with multiple regression, which controlled for age, sex, and IQ. Participants reported their physical activity behavior and were tested for reaction time (RT) and response accuracy on congruent and incongruent conditions of a flanker task, which manipulates interference control. After controlling for confounding variables, an age-related slowing of RT was observed during both congruent and incongruent flanker conditions. However, physical activity was associated with faster RT during these conditions, regardless of age. Response accuracy findings indicated that increased physical activity was associated with better performance only during the incongruent condition for the older cohort. Findings suggest that physical activity may be beneficial to both general and selective aspects of cognition, particularly among older adults.

The benefits of exercise training in multiple sclerosis

Multiple sclerosis (MS) is an immune-mediated disease characterized by inflammatory demyelination and neurodegeneration within the CNS. This damage of CNS structures leads to deficits of body functions, which, in turn, affect patient activities, such as walking, and participation. The pathogenesis and resulting consequences of MS have been described as concepts within the International Classification of Functioning, Disability and Health (ICF) model—an international standard to describe and measure health and disability. Evidence suggests that exercise training in people with MS has the potential to target and improve many of the components outlined in the ICF model. Although the body of research examining the effects of exercise training on depression, cognition and participatory outcomes is not sufficiently developed, some preliminary evidence is promising. Exercise training is proposed to affect inflammation, neurodegeneration, and CNS structures, but current evidence is limited. In this Review, we discuss evidence from clinical trials that suggests beneficial effects of exercise training on muscle strength, aerobic capacity and walking performance, and on fatigue, gait, balance and quality of life. Issues with current studies and areas of future research are highlighted.