Saturday, March 25, 2017

Validation and refinement of prediction models to estimate exercise capacity in cancer survivors

Exercise and physical activity is important for rehabilitation among cancer survivors. In a recent individual patient data meta analysis, we concluded that exercise, and particularly supervised exercise, effectively improves quality of life and physical fitness in patients with cancer with different demographic and clinical characteristics during and following treatment. Although effect sizes were small, there is consistent empirical evidence to support implementation of exercise as part of cancer care.
In order to test the effects of exercise interventions, to tailor exercise interventions, and to monitor progress among cancer survivors and patients with cancer, valid and reliable measures to assess exercise capacity are needed. In a paper just published in Archives of Physical Medicine and Rehabilitation -with Dr. Martijn Stuiver as first author- we tested the validity and clinical usefulness of the Steep Ramp Test for estimating exercise tolerance in cancer survivors, by external validation and extension of previously published prediction models for maximal or peak oxygen consumption (VO2peak; which is regarded as the gold standard measurement of cardiorespiratory fitness) and peak power output (Wpeak). Based on this study we concluded that predictions of VO2peak and Wpeak based on the steep ramp test are adequate at the group level, but insufficiently accurate in individual patients. The multivariable prediction model for Wpeak can be used cautiously to aid endurance exercise prescription.

Wednesday, March 22, 2017

Differences in Commuting to School and Work across Europe

In a study just published online in Preventive Medicine -with Dr. Saskia te Velde as first author- we explored if how school children and their parents commute to and from school and work across Europe, and if these modes of commuting are related to demographic variables, such as country of residence, sex, parental education, and ethnicity, and to weight status.
This study was part of the ENERGY project; children's weight and height were objectively measured; parents self-reported their weight and height and self-reports of mode of commuting and demographics were obtained.
There were marked differences between countries, especially regarding cycling to school, which was common in The Netherlands and Norway and rare in Greece and Spain. Mode of commuting was not associated with weight status in children, but parents who rode their bike to work were significantly less likely to be overweight or obese. Demographic variables were associated with mode of commuting in children and parents. For example: boys were more likely to cycle to school at least four days per week; girls were more likely to walk; children from lower educated parents were less likely to cycle, and children from ethnic minority groups were more likely to walk.

Tuesday, March 21, 2017

Social support and physical activity in young women in disadvantaged neighborhoods

People tend to become less physically active in transitioning from adolescence to adulthood. Evidence suggests that social support as well as 'intrapersonal' factors  such as self-efficacy, outcome expectations, enjoyment) are associated with physical activity. The aim of a study just published in PLOS One was to explore whether cross-sectional and longitudinal associations of social support from family and friends with leisure-time physical activity (LTPA) among young women living in disadvantaged areas were mediated by these intrapersonal factors, i.e. to explore if social support may help to increase self-efficacy, enjoyment et cetera, to help to increase LTPA. Firsts authors is Anouk Middelweerd, en this study was in close collaboration with and making use of data available at the Institute for Physical Activity and Nutrition at Deakin University, Australia.
Survey data were collected from 18–30 year-old women living in disadvantaged suburbs of Victoria, Australia as part of the longitudinal READI study.
Results from the cross-sectional analyses suggest that the associations of social support from family and from friends with LTPA are mediated by PA enjoyment, outcome expectations and self-efficacy. However, longitudinal analyses did not confirm these findings.