// Research review - Promoting workplace physical activity

by Dr Mike Climstein


: ‘An office-place stepping device to promote workplace physical activity’
Authors: Dr’s McAlpine, Manohar et al., (Mayo Clinic, USA).
Source: British Journal of Sports Medicine, 41: 903-907.

Finally, I get around to having cable TV installed in the hope of finding something worth watching, and what do I discover? Day and night, infomercials are taking up not one, but two entire cable channels! Yep, I’m paying a monthly price to listen to endless exhortations of ‘for the special price of…’. Apparently I can purchase the ultimate Abdominator to develop washboard abs, and the Gluteal Master to develop the ultimate legs and butt (as a lifelong squatter I really don’t feel the need for one of those).

Generally, I have a bit of a laugh at the numerous fitness wonder-products advertised on television and the claims of what they are able to achieve (while hoping that not too many viewers will be sucked in by them). But if I see a device which I think has potential, I will fire up the computer and go to Pubmed (free online search of research articles at www.ncbi.nlm.nih.gov/PubMed/) to see if there is any refereed literature available supporting or disproving the product’s claims. Well, lo and behold, I found an article on the ‘Discovery Electronic Mini Stepper’, and perhaps even more surprisingly, it appeared to support the product’s claims.

The Mayo Clinic is one of the most prestigious medical centres in northeast USA. Given the obesity epidemic in the United States, it is not surprising that the Mayo has investigated the effectiveness of a simple strategy to improve the levels of physical inactivity in adults. And what better strategy than incorporating the ‘treatment’ directly into the workplace, thereby eliminating the old excuse of not having enough time to exercise?

Dr McAlpine and his colleagues investigated the effects of what they refer to as ‘an office-place stepping device’ (Discovery Electronic Mini Stepper, USA) on energy expenditure as compared to walking and to sitting in a chair. Unlike treadmills and exercise bikes, this device is small enough to fit underneath the work desk when not in use.

Nineteen healthy adults volunteered to participate in the study, with the average age being 27 years and average weight 85 kilograms. Nine of the subjects were classified as ‘lean’ (BMI’s less than 25kg/m2) and ten were classified as obese (BMI’s greater than 29.9kg/m2). To determine the energy expenditure (via indirect calorimetry) and effectiveness of using the mini-stepper, subjects were tested while using the device, and for comparative reasons were also tested in a number of other activities which included sitting relaxed in a chair, and walking on a treadmill at speeds of 0.8, 1.6, 2.4, 3.2, 4 and 4.8kmph (0.5, 1, 1.5, 2, 2.5, and 3mph). The order of this testing was randomised.

The researchers state that, importantly, all subjects were able to use the device without injury, falls, or unsteadiness. The lean and obese subjects’ self-selected stepping rates were similar at 39 and 40 steps per minute respectively. With these stepping rates, the group as a whole (lean and obese) had an increase in resting energy expenditure of 1,256kj per hour (300 kcal per hour) and above sitting in an office chair by 1,210kj per hour (289kcal per hour). The comparative walking exercise naturally showed an energy expenditure increase with each increment of walking speed. The table below illustrates the energy expenditure for the subjects.

Additionally, the 1,402kj per hour (335 kcal per hour) expended by the obese volunteers was shown to be greater than the 983kj per hour (235 kcal per hour) used by the lean volunteers.

It is obvious from these findings that if an office worker were to walk at the highest speed of 5.6kmph (3.5mph) this would yield the highest caloric expenditure – higher than that achievable with the stepper. However, the subjects’ self-selected speed at which they would walk was more than 20 per cent slower than this, i.e., 4.1 to 4.6kmph (2.6 to 2.9mph), making it a less effective energy-burning activity than using the stepper.

The authors concluded that if office workers could replace sitting in their office chairs with stepping for two hours per day, a weight loss of 20kgs could occur.

PROS: Excellent article which substantiates the benefits of the Mini Stepper. It also empowers obese individuals to incorporate health into the workplace.

CONS: It would have been interesting to see how intensely the subjects were exercising (i.e., exercise heart rates). It would also have been intriguing to see the compliance of usage if the device were available at a workplace for an extended period of time.


Clinical Associate Professor Mike Climstein, PhD FASMF FACSM FAAESS DE
Dr Mike has an academic appointment with the School of Exercise Science, Australian Catholic University (NSW) and a clinical appointment as Director of Chronic Disease Rehabilitation at the Vale Medical Clinic. He is recognised as one of Australia’s leading clinical exercise physiologists working with patients suffering from a wide array of chronic diseases and disorders. For more information on any of the Research Reviews, please e-mail mike.climstein@acu.edu.au

NETWORK • AUTUMN 2008 • PP26-27