Treadmill workstations versus sit–stand desks for increasing physical activity
Authors: Andreas Holtermann
Journal: The Lancet Public Health (2018)

Sedentary behaviour for several hours per day is associated with health problems.1Biswas A Oh PI Faulkner GE Sedentary time and its association with risk for disease incidence, mortality, and hospitalization in adults: A systematic review and meta-analysis.Ann Intern Med. 2015; 162: 123-132Crossref PubMed Scopus (1279) Google Scholar Office workers spend a lot of their working hours sitting,2Danquah IH Kloster S Holtermann A et al.Take a stand! A multi-component intervention aimed at reducing sitting time among office workers—a cluster randomized trial.Int J Epidemiol. 2017; 46: 128-140PubMed Google Scholar and interventions for reducing their sitting time have foremost involved the implementation of sit–stand desks.2Danquah IH Kloster S Holtermann A et al.Take a stand! A multi-component intervention aimed at reducing sitting time among office workers—a cluster randomized trial.Int J Epidemiol. 2017; 46: 128-140PubMed Google Scholar, 3Healy GN Winkler EAH Eakin EG et al.A cluster RCT to reduce workers' sitting time: impact on cardiometabolic biomarkers.Med Sci Sports Exerc. 2017; 49: 2032-2039Crossref PubMed Scopus (50) Google Scholar Short-term reductions in sitting time from implementation of sit–stand desks are reported, but with small or no health effects.4Shrestha N Kukkonen-Harjula KL Verbeek JH Ijaz S Hermans V Pedisic Z Workplace interventions for reducing sitting at work.Cochrane Database Syst Rev. 2018; 6 (CD010912.)PubMed Google Scholar Physical activity seems to buffer the harmful health effects of excessive sedentary time.5Ekelund U Steene-Johannessen J Brown WJ et al.Does physical activity attenuate, or even eliminate, the detrimental association of sitting time with mortality? A harmonised meta-analysis of data from more than 1 million men and women.Lancet. 2016; 388: 1302-1310Summary Full Text Full Text PDF PubMed Scopus (1051) Google Scholar Thus, active workstations have been developed, which enable office workers not only to sit less, but also to be more physically active (eg, walking or cycling) while working.6Neuhaus M Eakin EG Straker L et al.Reducing occupational sedentary time: a systematic review and meta-analysis of evidence on activity-permissive workstations.Obes Rev. 2014; 15: 822-838Crossref PubMed Scopus (195) Google Scholar An example of these developments is integrated treadmill workstations for sit–stand desks, permitting office workers to walk while working. However, the effects of treadmill workstations had not been investigated in long-term randomised controlled trials. In The Lancet Public Health, Bergman and colleagues7Bergman F Wahlström V Stomby A et al.Treadmill workstations in office workers who are overweight or obese: a randomised controlled trial.Lancet Public Health. 2018; (published online Oct 12.)http://dx.doi.org/10.1016/S2468-2667(18)30163-4Summary Full Text Full Text PDF Scopus (18) Google Scholar did a randomised controlled trial to investigate whether treadmill workstations in office workplace environments increase objectively measured daily walking time among healthy overweight and obese office workers over 13 months. 80 participants were individually randomly assigned to the intervention group that received treadmill workstations or the control group that continued working at existing sit–stand desks. The intervention group was instructed to use the treadmill at a self-chosen walking speed for at least 1 h per day, and preferably more. The primary outcome of walking time and the secondary outcomes of number of steps, standing time, and sitting time were measured by an activPAL accelerometer on the participant's thigh for 7 consecutive days at baseline and at 2, 6, 10, and 13 months. Several health-related measures (anthropometric measurements, body composition, metabolic measurements, energy intake, salivary cortisol, subjective stress and energy, and depression or anxiety) were collected at baseline and at 6 and 13 months. The primary endpoint of a 30-min increase in physical activity was not met, but the authors were able to report that, between baseline and 13 months, the intervention group had a greater increase in weekday walking time and number of steps than the control group (18 min [95% CI 9 to 26] in the intervention groups vs 1 min [–7 to 9] in the control group). Notably, during the same period, the intervention group had a smaller increase in physical activity on weekends than the control group (5 min [–8 to 18] vs 8 min [–5 to 21]). No effect on daily time spent sitting was found (p=0·44). No significant intervention effects on anthropometric measurements, body composition, or any other health-related outcomes were found. The finding that implementation of treadmill workstations increases daily walking time over a rather long follow-up time among healthy office workers compared with sit–stand desks is novel. The intervention effects on daily walking time and number of steps were largest in the beginning of the study, after which it slowly attenuated but remained significant after 13 months. This attenuation of behavioural effects of workplace health promoting interventions is more the rule than the exception, and more studies investigating sustainability of these interventions are needed. The increased daily walking time of 22 min and 1646 steps ought to be sufficient to improve several health outcomes in an overweight and obese population. However, the absence of health effects might be explained by the quite high level of physical activity of the population at baseline, the fact that the intensity of the increased walking time might be too low to impose a substantial improvement in health,8Tudor-Locke C Han H Aguiar EJ et al.How fast is fast enough? Walking cadence (steps/min) as a practical estimate of intensity in adults: a narrative review.Br J Sports Med. 2018; 52: 776-788Crossref PubMed Scopus (92) Google Scholar and the smaller increases in weekend moderate and vigorous physical activity in the intervention group than in the control group. Thus, future interventions with active workstations for office workers should aim for a walking cadence of at least 100 steps per minute8Tudor-Locke C Han H Aguiar EJ et al.How fast is fast enough? Walking cadence (steps/min) as a practical estimate of intensity in adults: a narrative review.Br J Sports Med. 2018; 52: 776-788Crossref PubMed Scopus (92) Google Scholar and prevent compensatory reductions in moderate and vigorous physical activity during leisure time. The main strengths of the study by Bergman and colleagues7Bergman F Wahlström V Stomby A et al.Treadmill workstations in office workers who are overweight or obese: a randomised controlled trial.Lancet Public Health. 2018; (published online Oct 12.)http://dx.doi.org/10.1016/S2468-2667(18)30163-4Summary Full Text Full Text PDF Scopus (18) Google Scholar are the randomised controlled intervention design, the long follow-up time, and the use of repeated measurements with thigh-attached accelerometers to provide information on sitting, standing, and walking over several work and non-work days. The main limitations of the study are the absence of information on how much the intervention group used the treadmill workstations and the potential contamination between the intervention and control groups within the same companies (ie, the effect of controls seeing their colleagues in the intervention group walking at work). I applaud Bergman and colleagues for performing such a challenging and costly randomised controlled workplace intervention in several organisations with repetitive measurements over a long follow-up time of 13 months. The intervention provides the important and useful knowledge that implementation of treadmill workstations can feasibly increase daily walking time among office workers over availability of sit–stand desks. However, the treadmill workstations did not seem to improve the health of office workers who are already quite active. One main benefit of the treadmill workstation over other workplace exercise interventions is that the office worker can increase walking at the same time as doing productive work. In this manner, the benefits of increased physical activity among sedentary workers can be achieved without production loss for the company. To strengthen sustainability and scale-up of workplace physical activity interventions, a close integration of the physical activity with the main work tasks without reducing productivity ought to be strived for.9Holtermann A Mathiassen SE Straker L Promoting health and physical capacity during productive work: the Goldilocks principle.Scand J Work Environ Health. 2018; (published online July 18.)DOI:10.5271/sjweh.3754Crossref Scopus (21) Google Scholar Future randomised controlled trials investigating sustainable workplace interventions with the aim of increasing physical activity during productive work among sedentary workers are warranted. I declare no competing interests. Treadmill workstations in office workers who are overweight or obese: a randomised controlled trialIn a sedentary work environment, treadmill workstations result in a statistically significant but smaller-than-expected increase in daily walking time. Future studies need to investigate how increasing physical activity at work might have potentially compensatory effects on non-work activity. Full-Text PDF Open Access