Learnt effects of environmental cues on transport-related walking; disrupting habits with health promotion?

Daily stair climbing is associated with decreased risk for the metabolic syndrome

BACKGROUND

Stair climbing can be a vigorous lifestyle physical activity, and is associated with healthier lipoprotein profiles, lower body weight and blood pressure, as well as higher aerobic fitness. The present analysis of data from a cohort of late middle-aged men and women examined the association between daily stair climbing and the metabolic syndrome.

METHODS

Data from 782 (423 women) participants (mean (SD) age 58.3 (0.95) years in the Dutch Famine Birth Cohort Study (2002-2004) were used to examine the cross-sectional association between self-reported daily stair climbing and the metabolic syndrome. Stair climbing was assessed by the question 'Do you climb stairs daily?' and the metabolic syndrome was defined using the established five components relating to lipid fractions, blood glucose levels, blood pressure and abdominal obesity.

RESULTS

Not climbing stairs daily was associated with an increased incidence of the metabolic syndrome (OR = 1.90, 95% CI = 1.23, 2.92, p = 0.004) and a greater number of its components (F_1,780 = 8.48, p = 0.004): these associations were still evident after adjusting for a variety of potential confounders.

CONCLUSIONS

The most likely explanation for the current findings is that daily stair climbing may be protective against the metabolic syndrome. This result reinforces public health recommendations for increased stair climbing with evidence from physiological outcomes.

When weight is an encumbrance; avoidance of stairs by different demographic groups

BACKGROUND

Locomotion is an energy costly behaviour, particularly when it entails raising weight against gravity. Minimization of locomotor costs appears a universal default. Avoidance of stair climbing helps humans minimise their energetic costs. In public access settings, demographic subgroups that raise more 'dead' weight than their comparison groups when climbing are more likely to avoid stairs by choosing the escalator. Individuals who minimise stair costs at work, however, can accumulate a deficit in energy expenditure in daily life with potential implications for weight gain. This paper tests the generality of avoidance of stairs in pedestrians encumbered by additional weight in three studies.

METHODS

Pedestrian choices for stairs or the alternative were audited by trained observers who coded weight status, presence of large bags and sex for each pedestrian. Sex-specific silhouettes for BMIs of 25 facilitated coding of weight status. Choices between stairs and a lift to ascend and descend were coded in seven buildings (n = 26,981) and at an outdoor city centre site with the same alternatives (n = 7,433). A further study audited choices to ascend when the alternative to stairs was a sloped ramp in two locations (n = 16,297). Analyses employed bootstrapped logistic regression (1000 samples).

RESULTS

At work and the city centre site, the overweight, those carrying a large bag and females avoided both stair climbing and descent more frequently than their comparison groups. The final study revealed greater avoidance of stairs in these demographic subgroups when the alternative means of ascent was a sloped ramp.

DISCUSSION

Minimization of the physiological costs of transport-related walking biases behaviour towards avoidance of stair usage when an alternative is available. Weight carried is an encumbrance that can deter stair usage during daily life. This minimization of physical activity costs runs counter to public health initiatives to increase activity to improve population health.