Did you know that, as a nation, we watch quite a lot of television?
In a study published in the October issue of the British Journal of Sports Medicine, it turns out we watched a collective 9.8 billion hours of television in 2008.
The researchers also took account of a range of variables of the 12,000 adults involved in the Australian Diabetes, Obesity and Lifestyle Study, such as smoking, dietary quality, exercise habits, waist circumference, and then calculated the effect that sitting watching TV has on people’s life spans. It should be emphasised that the hazard being measured here is not watching TV, but the hours spent sitting, of which watching TV is an example and is simple for volunteers in a research study to measure.
The findings are startling.
According to one of the study’s authors, Dr Lennert Veerman of the School of Population Health at the University of Queensland, for every single hour of watching television after 25 years of age, our life expectancy is reduced by almost 22 minutes.
If you’re 25, that might not sound like much; but if you’re 55, it does; and if you’re 85, it’s sobering. By comparison, smoking one cigarette reduces life expectancy by about 11 minutes according to the authors. They concluded that an adult who spends an average of six hours a day watching TV over the course of a lifetime can expect to live 4.8 years fewer than a person who does not watch TV.
But if that’s not enough, Dr Veerman says that it doesn’t make much difference even for people who exercise regularly.
“A person who does a lot of exercise but watches six hours of TV [each night] ... might have a similar mortality risk as someone who does not exercise and watches no TV.”
In other words, even if we do the ‘right thing’ and exercise regularly, we are at risk if we sit a lot – although that’s not a reason to stop exercising.
Why is sitting not good? It’s not fully understood but a lead author of the report Professor David Dunstan, Head of Physical Activity at the Baker IDI Heart and Diabetes Institute in Melbourne, who actively studies sedentary behaviour, says “The most striking feature of prolonged sitting is the absence of skeletal muscle contractions, particularly in the very large muscles of the lower limbs.”
In other words, when muscles don’t contract, they require less fuel and the surplus, in the form of blood sugar, accumulates in the bloodstream contributing to diabetes and other chronic health risks.
Professor Dunstan says the first thing to do is to reduce your sitting time, and TV is an easy one to start with.
“The evidence indicates that four hours per day is in the ‘risky’ category, while less than two hours per day is in the lower-risk group.”
But even if you do manage to confine your TV time to two hours a day, there’s approximately another 14 hours to be concerned about each day. Here are a few things you can do (some serious, some just a bit lighthearted):
- We’ve published this story on a Sunday. Instead of sitting reading it, take your smartphone, go for a walk and read it and the rest of Motherpedia while you’re walking!
- Stand on public transport.
- Volunteer to have the desk at work which is furthest away from the lift, kitchen and toilets (it has other benefits).
- Better still, don’t take the lift, but take the stairs.
- Don’t sit while you have a coffee break.
- You don’t need to sit to speak on the telephone.
- Have a ‘West Wing’ style meeting: walk and talk at the same time, or simply congregate in the corridor (see picture).
- Next time your boss says "I want you to sit down", reply "I really would rather stand in the interests of my occupational health and safety."
- Make risotto – because to make it perfectly, you have to stand and stir it.
- Take up a profession where you stand a lot – hairdressing, retail sales, nurse, teacher, house painter, hospital doctor to name a few.
- Go somewhere where the national anthem is played regularly.
- Join a marching band.
- Mow the lawn or do some digging.
- Someone has to do it sometime - the ironing - if it's you, iron while watching TV.
- Have a shower, not a bath.