Circadian rhythms are physical and behavioral changes that follow a 24-hour cycle in response to light and darkness. They influence various bodily functions like melatonin production, hormone release, and body temperature. Exposure to bright morning light can help treat insomnia, premenstrual syndrome, and seasonal affective disorder by advancing melatonin rhythms. Prolonged sitting has been linked to health risks like reduced metabolism and increased risk of diabetes and cardiovascular disease. Introducing sit-stand desks in the workplace can substantially reduce sitting time and may improve public health by countering sedentary behaviors.

1. Formoreinfovisitwww.aerodesk.co.ukorcallHeadOffice01189739716
STAND UP TO SITTING DOWN
The importance of reducing sedentary behaviour in the workplace
SHEDDING LIGHT ON WELLBEING
Using light to improve health & wellbeing

2. WHAT ARE CIRCADIAN RHYTHMS?
Circadian rhythms are physical, mental and behavioral changes that follow a roughly 24-hour
cycle, responding primarily to light and darkness in an organism’s environment.
They are found in most living things, including animals, plants and many tiny microbes. The study
of circadian rhythms is called chronobiology.
Circadian rhythms are produced by natural factors within the body, but they are also affected by
signals from the environment. Light is the main cue influencing circadian rhythms, turning on or
turning off genes that control an organism’s internal clocks.
SLEEP / WAKE
CIRCADIANRHYTHMSCANINFLUENCE
MELATONIN
PRODUCTION
HORMONE
B O D Y T E M P E R A T U R E
R E L E A S E
BI-POLAR
SEASONAL
AFFECTIVE
DISORDER
OBESITY
DIABETES
I N S O M N I A
CYCLES

3. CONQUER THE WINTER BLUES (SAD)
Studies have suggested that the relative
shortage of daylight exposure for office
workers during daily life could well compromise
their health and wellbeing, which in turn has
stimulated interest in the applications of light in
the corporate setting.
Whilst outdoor illuminance typically ranges from
between 2000 and 100,000 lux, within an office
environment this is often considerably lower,
with norms of approximately 500 lux. Also
noted is that typical fluorescent indoor lighting
contains considerably less short wavelength
“blue spectrum” light than natural daylight,
precisely the component of the spectrum
thought to be highly relevant for achieving non-
visual, biological effects.
When people are exposed to sunlight in the
morning, their nocturnal melatonin production
occurs sooner, and they enter into sleep more
easily at night. The melatonin rhythm phase
advancement caused by exposure to bright
morning light has been effective against
insomnia, premenstrual syndrome, and
seasonal affective disorder (SAD). Whereas
high melatonin levels correspond to long nights
and short days, high serotonin levels in the
presence of melatonin reflect short nights and
long days. Moderately high serotonin levels
result in more positive moods and a calm yet
focused mental outlook. Indeed, SAD has been
linked with low serotonin levels during the day
as well as with a phase delay in nighttime
melatonin production.

4. Risks of prolonged sitting
Reduced metabolism
Reduced insulin effectiveness
Reduced enzyme activity
Electrical activityin leg muscles shuts down
Increased risk oftype 2 diabetes
Increased risk ofobesity
Increased risk ofcardiovsculardisease
We are spending increasing amounts of time in
a sedentary position.
Whether at work, at home or travelling
between the two, compared to earlier
generations we are spending more time in
environments which limit physical activity and
encourage prolonged periods of inactivity.
The association between sedentary behaviour
and the impact on health is nothing new and
has been documented from as early as the
1950s.
A large amount of research has been
published citing a number of potential health
risks associtaed with prolonged periods of
sedentary behaviour.
76%of a working day office
workers spend sedentary
UP TO
First documented amongst London bus drivers,
a study found they were twice as likely to
suffer heart attacks than their conductor
colleagues. Over the subsequent decades
our tendancy for inactivity has progressively
worsened, with work requiring less physical
activity, combined with more sedentary
pursuits at home, such as extended periods
watching television. This was illustrated by a
2011 study which highlighted that an average
adult then spent 50%-60% of their waking day
in sedentary environments.

5. Much of the rise in the prevalence of chronic
disease in the past decades has been
attributed to changes in behavioural risk
factors: in particular, physical inactivity, poor
nutrition and, as recently identified, time spent
sitting (AIHW 2009; Hamilton, Healy et al.
2008; Dunstan, Barr et al. 2010).
The stand@work controlled trial pilot
found that introducing sit-stand desks can
substantially reduce time spent sitting and their
introduction was feasible in the workplace.
and ‘might have public and occupational
health potential for an increasingly sedentary
workforce’ (Chau JY et al 2014).
There is a large amount of research into the
associated advantages and disadvantages
of sitting and of standing, such as Roelof and
Straker (2003) and Visser and Straker (1994).
The assumption is that neither sitting
or standing for extended periods is
recommended, but a workstation which can be
altered throughout the day. This reduces the
workload experienced by our bodies and the
greatest percentage reduction in discomfort as
the day progresses.
Research by the University of Chester looked
into the benefits that standing can have during
a working day, focussed on how this can
improve metabolism, calories expended and
fat burnt.
The results showed from the small group was
that by standing for three hours a day for five
days the group burnt around 750 calories,
which would equate to around 30,000 calories
across a year.
STANDING FOR 3 HOURS A DAY BURNS
30,000extra calories per year, equivalent
to running 10 marathons

6. References
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