The effect of two different 18-week walking programmes on aerobic fitness, selected blood lipids and factor XIIa

Forty-nine previously sedentary or low active individuals aged 40-71 years were allocated to three groups. The long walking group participated in an 18-week walking programme which consisted of walks lasting 20-40 min; the repetitive short walking group completed walks of between 10 and 15 min, up to three times a day, with no less than 120 min between each walk; and the control group maintained their low level of activity. Both walking programmes began at a prescribed 60 min x week(-1), which increased steadily up to 200 min x week(-1) by week 12. During the study, the long walking group walked for an estimated 2514 min (139 min x week(-1)), expending an estimated 67.5 MJ (3.72 MJ x week(-1)) at an estimated 73% of their age-predicted maximum heart rate and 68% of their estimated VO2max. The repetitive short walking group walked for an estimated 2476 min (135 min x week(-1)), expending an estimated 58.5 MJ (3.17 MJ x week(-1)) at an estimated 71% of their age-predicted maximum heart rate and 65% of their estimated VO2max. The results showed a statistically significant reduction in heart rate during a standardized step test (pre- vs post-intervention) in both walking groups, indicating an improvement in aerobic fitness, although the control group showed a higher average heart rate during the post-intervention test, indicating reduced fitness. When compared with the male subjects pre-intervention, the females possessed more favourable levels of high-density lipoprotein (HDL) cholesterol (P< 0.001), apolipoprotein (apo) AI (P < 0.001) and ratios of total cholesterol:HDL cholesterol (P< 0.02) and low-density lipoprotein (LDL) cholesterol: HDL cholesterol (P< 0.02). Compared with the controls post-intervention, the walking groups showed no statistically significant changes in total cholesterol, LDL cholesterol, HDL cholesterol, apo AI, apo AII, apo B, or the ratios of total cholesterol: HDL cholesterol, LDL cholesterol: HDL cholesterol, apo AI: apo B or apo AI: apo AII (P > 0.05). Relative to the walking groups, factor XIIa increased in the control group (P < 0.05). We conclude that, although both walking programmes appeared to improve aerobic fitness, there was no evidence of improvements in the blood lipids or associated apolipoproteins of the walking groups. Further analysis indicated that this apparent lack of change may have been related to the subjects' relatively good pre-intervention blood lipid profiles, which restricted the potential for change. The implications of the observed changes in the coagulation/fibrinolytic factors remain unclear.     

Science in Action: How Middle School Students Are Changing Their World Through STEM Service-Learning Projects

The purpose of Science in Action (SIA) was to examine the relationship between implementing quality science, technology, engineering, and math (STEM) service-learning (SL) projects and the effect on students' academic engagement in middle school science, civic responsibility, and resilience to at-risk behaviors. The innovative project funded by the Corporation for National and Community Service (CNCS) included 6,000+ middle school at-risk students (eligible for at least 50% free or reduced-cost lunch), 126 science teachers who integrated STEM problem-based SL pedagogy into science instruction to teach students to solve real problems in schools and communities. The project involved 20 schools and communities with assistance from 120 community partners. Participants completed pre- and post-SL surveys on academic engagement, civic responsibility, and resilience; qualitative data were collected from journals, interviews, focus groups, observations, and field notes. Results highlight exemplary SL projects that demonstrated increased student academic engagement and achievement for students living in high poverty areas with potential at-risk behavior. Implications for future research and educational practices are discussed.     

A Cultural-historical Critique of How Engineering Knowledge is Constructed Through Research in Play-based Settings: What Counts as Evidence and What is Invisible?

Research in Science Education - It is reported that engineering for play-based settings is a new body of knowledge under debate and contradictory. Many studies show how play-based settings are full...     

Empowering Marginalized Youth: A Self‐Transformative Intervention for Promoting Positive Youth Development

This article reports the results of a positive youth development (PYD) intervention for adolescents in alternative high schools (209 African American and Hispanic American adolescents, aged 14–18; 118 females and 91 males). The intervention was guided by a self‐transformative model of PYD (Eichas, Meca, Montgomery, & Kurtines, 2014). This model proposes that the actions youth take to define themselves function as active ingredients in positive development over the life course. Consistent with the self‐transformative model, results provided support for direct or mediated intervention effects on the self‐transformative processes of self‐construction and self‐discovery, life goal development, identity synthesis, and internalizing problems. The findings illustrate the utility of using a self‐transformative approach to PYD in work with marginalized youth populations.