Mid-term Effect of a Novel Sit-to-stand Workplace (ACTIVE OFFICE) on Cognitive and Physiological Parameters
Condition: Sedentary Lifestyle; Worksite
Study type: Interventional

Summary: 
      Prolonged sitting is a risk factor for cardiovascular and musculoskeletal diseases, diabetes,
      several types of cancer and all-cause mortality. In combination with static and awkward
      postures, the prevalence of musculoskeletal diseases can increase further. Although the
      implementation of sit-to-stand or active workstations can help to reduce sitting time,
      improve physical activity at work and promote health benefits, it might also lead to changes
      in cognitive functions such as productivity The purpose of this study is to evaluate the
      mid-term effect of a novel two desk sit-to-stand workplace on sitting time as well as
      physiological and cognitive parameters for healthy people of working age in comparison to
      their traditional workplace.
    

Detailed description: 
      Measurements were made both in the field and in a laboratory. Field measurements were made
      and processed continuously over the 23-week intervention period. Laboratory measurements were
      made on two different days, one day prior to intervention, and one day following intervention
      (due to cross-over design, each subject underwent 4 total days of laboratory measurements).
      Field measurements were collected automatically at the participants' workstation in their
      working office.

      Laboratory tests were conducted in a controlled, simulated work-space located at the
      University of Applied Sciences Campus Linz. All laboratory measurements were made in a
      controlled laboratory at the campus site Linz of the University of Applied Sciences Upper
      Austria. Temperature, air flow, humidity, lighting conditions (artificial light only) and
      noise level were controlled and set to be consistent with the subjects' typical working
      environment.

      During the laboratory measurements, subjects either stood or sat upright in an ergonomic
      office chair, according to the study protocol. Subjects were encouraged to work as fast and
      as accurately as they could. To ensure identical testing conditions between subjects and to
      not unduly influence physiological parameters such as salivary cortisol level or heart rate
      variability, subjects were required to minimize excessive movement (e.g. standing up during
      the sitting periods).

      In the first (initial) phase, participants were familiarized with the study protocol. Sitting
      time and weekly physical activity were determined via the IPAQ-questionnaire. Examples of
      each cognitive test implemented in the cognitive phase were executed according to their
      guidelines. A 30 minute break in a sitting posture was used to ascertain baseline heart-rate
      and cortisol level. Baseline heart-rate was calculated after a 20 minute rest for a 5 minute
      interval and saliva samples were collected at the end (30min) of the break.

      In the second (cognitive) phase subjects participated in a test battery containing five
      blocks. Each block consisted of a working speed test (text editing task), an attentional test
      (d2R-test of attention) and a reaction time test (Stroop-test). These tests lasted for 30
      minutes to fulfill recommendations regarding postural changes. To simulate "common" working
      conditions (computer based and non-computer based tasks), digital (text editing task,
      Stroop-test) as well as pen & paper (d2R-test) versions of the implemented tests were used.
      All blocks were executed in alternating postures (sit - stand - sit - stand - sit) and at the
      end of each block - after a 5 minute break - salivary samples were collected. The order of
      posture was not changed within groups or time.

      In the third (final) phase participants were asked to estimate their workload by means of the
      NASA-TLX questionnaire followed by a 30 minute resting phase in a sitting posture. During
      both 30 min resting phases (initial & final) participants watched documentaries and were
      encouraged not to talk.

      Salivary samples were collected after each break during the study protocol and on the
      following morning, 20 minutes after waking up, to ascertain cortisol awakening response
      (CAR). Salivary samples were centrifuged and stored at -80 °C for subsequent testing using a
      chemiluminescent immunoassay.

      Heart-rate and trunk movements were measured from the start of the study protocol until the
      CAR measurement.
    

Intervention name(s): Workplace consisting of two height-adjustable desks
Intervention type(s): Other
Intervention description(s): Desk arrangements: self-determined by the participants Desk equipment: depending on pre-intervention condition - 1 or 2 screens per desk Build-up: one day prior to the intervention period at the location of the workplace Adjustment: together with the study leader
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: postural changes; Height adjustable desk; Prolonged sitting; Cognitive performance