Dr Jo Blodgett, Research Fellow at The Institute of Sport, Exercise and Health (ISEH), has recently published research with colleagues from The ISEH and UCL, John Mitchell PhD Student and Professor Mark Hamer, Chair in Sport and Exercise Medicine. The research was a group study conducted with fellow researchers Prof Emmanuel Stamatakis and Prof Sebastian Chastin, whom, as a collective, examined how time spent in different behaviours relative to others across the 24-hour day (i.e. sleep, sedentary behaviour, light-intensity activity, moderate-vigorous activity) were associated with depressive symptoms.
Most research tends to focus on a single behaviour in isolation (often moderate-vigorous activity), which fails to recognise the behavioural and biological interdependences of all behaviours across the day. The authors used a novel statistical approach called compositional data analysis, which enables them consider how the relative time spent in sleep, sedentary behaviour and varying activity intensities is associated with depression. The researchers could also quantify how replacing one behaviour with another (i.e. replacing sedentary behaviour with light intensity) impacted depression risk
The study revealed that more time people spent in light or moderate-vigorous intensity activity and less time spent sedentary or sleeping was associated with decreased risk of depression. However, the effects of replacing sleep, sedentary or light activity with each other was quite small and required a substantial amount of change; for example, a 20% lower depression risk was seen if 4 hours of sleep or 1.5 hours of sedentary behaviour were replaced by light activity. Conversely, replacing any behaviour with higher intensity activity had benefits even at small levels; reallocating 18-25 daily minutes of sleep, sedentary or light activity into moderate-vigorous activity was associated with the same 20% lower depression risk.
Led by Dr Jo Blodgett, she shares: Although our study results add to the overarching 'Move more, sit less' public health message, our findings highlight the crucial need for higher intensity activity to modify the risk of depression. Preventative and treatment policies for depression must ensure that any activity recommendations include specific moderate-vigorous activity such as brisk walking, cycling, or running.
To read the published research, visit ScienceDirect.