Fidgeting probably not a useful alternative to prope...

"Fidgeting 'offsets unhealthy effects of sitting for long periods and may help you live longer'," the Daily Mirror reports.

A new study reported fidgeting may help make up for the harmful effects of most people's sedentary lifestyles. Sitting down for most of the day has been linked to an increased risk of diabetes and heart disease.

A study following more than 10,000 women for 12 years found an association between high levels of self-reported fidgeting and reduced risk of death. This was despite them spending several hours a day sitting.

But while the media reports fidgeting is therefore good for you, this study had major limitations and the results were mixed.

The women were asked to rate how much they fidget on a scale of 1 (none) to 10 (constantly) in a single questionnaire. Other details, such as activity level, amount of time sitting, occupation and diet, were also only collected at a single point in time.

These estimates may be inaccurate, and each factor may have changed over the study period. This means we cannot be confident fidgeting reduces the negative effects associated with a sedentary lifestyle.

Going for a brisk walk, jog, or swim is almost certainly better for you than tapping your feet. Read more about the benefits of regular exercise.

Where did the story come from?

The study was carried out by researchers from University College London, Heriot-Watt University, the University of Edinburgh, and the University of Leeds.

It was funded by the World Cancer Research Fund, the Biotechnology and Biological Sciences Research Council, and the Medical Research Council. No potential conflicts of interest were reported.

The study was published in the peer-reviewed American Journal of Preventive Medicine.

In general the UK media reported the findings of the study at face value, not mentioning any of the study's limitations.

The Guardian incorrectly described fidgeters as people whose "limbs tapped, wobbled and gently vibrated" or "colleagues who are constantly tapping their feet", but this was not how the questionnaire asked women to rate their level of fidgeting.

What kind of research was this?

This cohort study followed more than 10,000 women over a period of 12 years to see if there was a link between fidgeting, the amount of time spent sitting, and risk of death.

Cohort studies like this are a good way of finding associations between environmental and lifestyle factors and outcomes because they can involve large numbers of participants and are done over a long period of time to capture the long-term effects of an exposure.

However, they cannot prove cause and effect, which would require a randomised controlled trial. Such a trial would be tricky to organise, however.

What did the research involve?

The researchers analysed data on a sample of 10,937 women who participated in the United Kingdom Women's Cohort Study (UKWCS).

These women completed a sociodemographic and food frequency questionnaire at some point between 1995 and 1998. At that time they were aged between 35 and 69.

They completed a second questionnaire between 1999 and 2002, which included information on health behaviours, illness, 24-hour activity, physical activity and fidgeting.

Fidgeting was assessed on a scale from 1 to 10 using the question, "How much of your time do you spend fidgeting?". A score of 1 would mean "no fidgeting at all", with 10 indicating "constant fidgeting".

The women were followed up until December 2013. The results were analysed to look for an association between the level of self-reported fidgeting and risk of death.

The researchers adjusted the results to take into account the following possible confounding factors:

age
chronic disease
physical activity level
sitting time
level of education
occupational social class
retirement status
smoking status (current versus former or never)
alcohol use
fruit and vegetable consumption
hours of sleep

The researchers performed additional analyses to see if body mass index (BMI) could account for the results seen.

What were the basic results?

Women who reported the lowest fidgeting rate had a 30% increased risk of death from any cause if they sat for seven or more hours a day compared with less than five hours (hazard ratio [HR] 1.30, 95% confidence interval [CI] 1.02 to 1.66).

For women in the highest self-reported fidgeting group, sitting for five or six hours a day was associated with a 37% reduction in risk of death compared with sitting for less than five hours a day (HR 0.63, 95% CI 0.43 to 0.91).

Sitting for longer than six hours a day was not associated with an increased or decreased risk of death in this group.

The length of sitting time was not associated with risk of death in women classed as being in the middle group of fidgets. BMI did not alter the results.

How did the researchers interpret the results?

The authors concluded that, "Fidgeting may reduce the risk of all-cause mortality associated with excessive sitting time." They called for "more detailed measures of fidgeting … to replicate these findings".

Conclusion

This cohort study found fidgeting may reduce the risk of death associated with sitting for long periods of time.

The study's strengths include the large number of participants, long follow-up period and attempts to account for a number of potential confounding factors.

However, the study is purely based on one self-reported estimate of most of these factors, which reduces confidence in the strength of the results. Fidgeting is largely an unconscious activity, so many people could have no accurate recall of how much or how little they fidget.

Not only could the estimates be unreliable, but many of these variables may have changed over the course of the 12 years of follow-up, such as activity level, diet, smoking and employment status.

The analyses did not consider whether the sitting was related to occupation, leisure time or watching TV, which may have influenced the results.

A further major limitation is in the assessment of the amount of fidgeting. Again, this was only assessed on one occasion through the women guessing how much they fidget on a scale of 1 to 10. This was not validated through any objective measurement or asking family, friends or colleagues to see if they agree.

The researchers suggested future studies could try to address this limitation through combining the self-report with tri-axial accelerometers (movement sensing devices that people wear).

In conclusion, though interesting, the results of this study do not lead to a call for people to fidget more. Instead, the advice remains the same: stop smoking, drink alcohol within safe limits, eat a balanced diet that includes plenty of fresh fruit and vegetables, and keep physically active.