How many calories are burnt per hour sitting on an exercise ball?

Question

How many calories are burnt per hour sitting on an exercise ball?

I have seen a number of 350 calories extra per day being tossed around on internet with no evidence or explanation. I assume thats the max that has been claimed. SO it would be around 45 calories per hour (claimed)...

Does anyone have any evidence/information about this?

p.s. I have read comments/articles on the negative aspects of replacing a chair with an exercise ball. Thats a different question, i am just interested in average calories burnt per hour for male/female.

Answer 1

According to this paper, about 4.1 kcal per hour above what you would have burned sitting in an office chair.

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Sitting on a therapy ball or standing may be a passive means of increasing energy expenditure throughout the workday. The purpose of this study was to determine the energy expenditure and liking of performing clerical work in various postures. Subjects included 24 men and women employed in sedentary clerical occupations. Energy expenditure was measured while word processing in three standardized postures; sitting in an office chair, sitting on a therapy ball, and standing. Adults ranked their comfort, fatigue, and liking of each posture and were asked to perform their choice of 20 min of additional clerical work in one of the postures. Energy expenditure was 4.1 kcal/h greater (p on a therapy ball and standing than while sitting in an office chair. There was no difference in energy expenditure between the therapy ball and standing postures (p >or= 0.48). Subjects also liked sitting on a therapy ball as much as sitting in an office chair and liked sitting on a therapy ball more than standing.

Compare to walking fast, which can consume about 5.0 kcal per minute.

Answer 2

I did some small, very unscientific testing myself. I sat on a chair and ball for 2x30 minutes and averaged the heart rate and kcal/5 min. The bump at the beginning was caused by me drinking coffee. As you can see the heart rates are very similar and the difference in kcal is pretty negligible too.

On average I burn about 1-1.1 kcal / minute, which is pretty low given that my 2hr run yesterday burned an average of 12 kcal/minute.

So while your mileage may vary, I'd probably burn somewhere between 60 and 90 kcal/hour regardless on what I'm sitting. To get 45 kcal more, you'd probably need to be in some very unbalanced position.