Inactivity, Sedentary Behaviour and Mental Health

Question 1

What demographic groups have lower levels of physical activity?

Answer 1

PA decreases with age, females, non-caucasion ethnicities, lower education levels, lower SES

Question 2

What methods are there to measure physical activity behaviour?

Answer 2

Subjective/self-report - questionnaires and interviews
Objective - heart rate monitor, pedometer, accelerometer
Observational - direct and indirect viewing
Have to consider validity, reliability, cost when choosing which method to use

Question 3

Define sedentary behaviour.

Answer 3

Activities which require minimal body movement resulting in energy expenditure similar to resting level (i.e. 1-1.5 METs)
Can be non-discretionary (e.g. sitting whilst commuting) or discretionary (e.g. TV/video-games)

Question 4

What is the relationship between sedentary behaviour and depression?

Answer 4

Teychenne et al. (2010)’s systematic review of 7 observational and 4 interventional studies found SB was positively associated with increased risk of depression.
However, the interventional studies were less supportive (mixed results), small number of studies used, can’t conclude causality and most studies used self-report

Question 5

What is the relationship between sedentary behaviour and anxiety?

Answer 5

Teychenne et al. (2015)’s systemic review of 9 studies suggested moderate evidence for a positive relationship between total SB and anxiety risk as well as total sitting time and anxiety risk.
However, only 9 studies, only 1 of which had strong methodological quality, can’t conclude causality, most used self-report, few assessed total SB

Question 6

What hypothesis exists suggesting a reason for worse mental health as a result of SB?

Answer 6

Social withdrawal hypothesis: SB means people are engaged in more isolated activity (e.g. video games alone)
However, if socialising whilst engaging in the SB (e.g. chatting online/group video games), there could be a decreased risk of depression

Question 7

What alternative explanation exists as to why SB may harm mental health?

Answer 7

SB may displace PA, which has shown to be beneficial in reducing the risk of depression in adults

Question 8

Through what mechanism is sedentary behaviour thought to increase anxiety risk?

Answer 8

Screen-based entertainment (e.g., video gaming) has been shown to increase the arousal of the central nervous system (CNS) and disrupt sleeping patterns, which can lead to increased levels of anxiety