Devil makes work for idle hands

Leisure-time sedentary behaviour is strongly associated with alcohol, tobacco and drug use among adolescents, writes KARL PELTZER, research director in the HIV/AIDS, STIs and TB research programme, HSRC.

Physical inactivity leads to higher levels of illness (morbidity) and deaths (mortality) from chronic non-communicable diseases. In high-income countries, studies have measured physical activity and substance use among school-goers, but comparable data is lacking from most African countries.

The purpose of this study was to look at the relationship between the frequency of leisure-time physical activity and sedentary behaviour, and alcohol, tobacco and drug use among schoolchildren.

We conducted a nationally representative survey among a sample of 24 593 schoolchildren in the age group 13 to 15 years from eight African countries, namely Botswana, Kenya, Namibia, Senegal, Swaziland, Uganda, Zambia and Zimbabwe.

In the findings, only 14,2% of the schoolchildren were frequently physically active (five days and more per week, at least 60 minutes a day) during leisure time. This was significantly higher among boys than girls.

Frequency of alcohol consumption and higher socioeconomic status were significantly associated with leisure-time physical activity levels, while tobacco, illicit drug use, and mental health variables were not. Leisure-time sedentary behaviour of five or more hours spent sitting down on an average day was highly associated with all forms of substance use.

Physical vs sedentary activity

Leisure-time physical activity was described as: ‘Any activity that increases your heart rate and makes you get out of breath some of the time’, whether in sports, playing with friends, or walking to school. Some examples are running, fast walking, riding a bike, dancing and football.

Leisure-time sedentary behaviour was described as mostly sitting when not in school or doing homework, for example: ‘How much time do you spend during a typical or usual day sitting and watching television, playing computer games, talking with friends, or doing other seated activities?’

Five or more hours spent sitting on an average day during leisure time were highly associated with substance use of all kinds.

Alcohol and drug use

Overall, 15% reported past month alcohol use. The highest frequency of alcohol use was reported by Zambian and Namibian schoolchildren (42,3% and 32,8% past month, 5,6% and 3,7% typically five or more drinks a day respectively), and the lowest frequency among Senegalese school children (3,2% past month and, 0,2% who drank five or more drinks a day).

Similarly, illegal drug use was highest among Zambian and Namibian schoolchildren (38,1% and 28,8%, respectively) and the lowest among Senegalese schoolchildren (0,6%). Boys reported tobacco and alcohol use significantly more often than girls, while there was no significant gender difference for illegal drug use.

Regular and frequent physical activity levels were associated with lower use of alcohol, and five or more hours spent sitting on an average day during leisure time were highly associated with substance use of all kinds. This has implications for the promotion of physical activity and prevention of substance abuse. In addition, children should be discouraged from sitting for extended periods.

Getting them off teh couch

More research is needed on the cognitive, social, and environmental factors that may influence physical activity, time spent sitting, and substance use levels among adolescents so that effective interventions can be developed that may help children and adolescents become more active.

It is also imperative to consider exercise and physical activity as a means to prevent and combat the childhood obesity epidemic. 

In African countries, different kinds of interventions targeting ‘total physical activity’ in the domains of work, active transport, reduced sitting time, as well as leisure-time physical activity promotion are needed.

Summary of an article, Leisure time physical activity and sedentary behaviour and substance use among school adolescents in eight African countries, published in the International Journal of Behavioural Medicine (2010).