In fact, political centrists would do well to stop 'sitting on the fence' and boost their physical activity levels to improve their health, say the researchers.
The term "armchair socialist" was coined in the 19th century by German economists who scoffed at academics advocating social policy, dubbing them "socialists of the chair" (Kathedersozialisten).
The term has since evolved to describe middle class people who talk a lot about politics but who aren't politically active in any way, and fail to "walk the talk."
The concept has been widely adopted, prompting several variations on the theme, including "limousine liberal," "chardonnay socialist," "champagne socialist," and "armchair revolutionary."
In a bid to find out if armchair socialists really do spend a lot of time sitting down, and talking rather than doing, the researchers analysed responses to the 2005 Eurobarometer survey, carried out on behalf of the European Commission.
The survey involved more than 29,000 adults, with an average age in the mid-40s, from 32 European countries. Among other things, respondents were asked about the amount and intensity of physical activity they did every week, including how much time they spent sitting down.
And they were asked to score their political orientation from 1 (rabid left wing) to 10 (far right wing). Those with scores between 3 and 8 were described as centrists.
Some 1,985 (6.8%) respondents declared themselves to be on the extreme left of the political spectrum, while 1,902 (6.5%) said they were on the far right. A further 17,657 (60.5%) espoused centrist views. Some 7,649 people (26.2%) didn't reveal their political beliefs.
The responses showed that people on both ends of the political spectrum spent more time engaged in vigorous physical activity every week than centrists. And they spent significantly more time walking.
Overall, left wingers were physically active for almost an hour more (just under 59 minutes) every week than centrists, while right wingers were over an hour (just over 62 minutes) more active.
Those who didn't admit to any political affiliation were the most physically inactive of all, clocking up 40 fewer minutes of physical activity every week than centrists.
Political extremists on the right also spent almost 13 fewer minutes a day sitting down than centrists, while centrists and left wingers spent a similar amount of time seated, after taking account of influential factors.
"Our findings refute the existence of an armchair socialist," write the researchers, adding: "Busy people at both ends of the political spectrum do not seem to have as much time for idleness." The higher physical activity levels reported by political extremists suggest that they might be out "agitating in the field, mobilising the community, and actively distributing ideas and propaganda," they say.
"It is those sitting in the middle (politically) that are truly inactive, and may be sitting more (both on the fence and elsewhere), making them a defined at-risk group," they warn.
And they go on to suggest: "The politically uncommitted and centrists should consider adopting a stronger political stance for their health. This may also reduce their sitting time, particularly if they shift their views to the right."