How sickening is sitting: experimental evidence

Recent experimental studies demonstrated that, when compared to prolonged
sitting, interruptions during prolonged sitting significantly reduced
postprandial glucose, insulin and C-peptide in healthy young adults. One study
could not establish this in children. Thus far, no studies have examined the
possible positive effects of standing interruptions to prolonged sitting or
active sitting. Moreover, to date, no studies are performed in overweight/obese
children, who may be at increased risk for cardiometabolic ill-health. This
information is essential to inform preventive interventions and guidelines on
sedentary behaviour in children.

18-22 YEAR OLD MALES WIHT A NORMAL WEIGHT
Examine the possible attenuating cardiometabolic health effects of (A) hourly,
10-min standing interruptions, when compared to a single bout of prolonged
sitting, and (B) sitting on a stability ball, when compared to a single bout of
prolonged sitting, in healthy young males.

14-18 YEAR OLD MALES WITH OVERWEIGHT/OBESITY
Examine the possible attenuating cardiometabolic health effects of (A) 10-min
standing interruptions every 30 min, when compared to a single bout of
prolonged sitting, and (B) 4-min cycling interruptions every 30 min, when
compared to a single bout of prolonged sitting, in overweight/obese young males.

For details see document "C2. Amendement".

18-22 YEAR OLD MALES WIHT A NORMAL WEIGHT
Experimental study with a cross-over design, including three experimental
conditions, lasting 5 hours each:
1) prolonged sitting on a lounge chair;
2) prolonged sitting on a lounge chair with hourly 10-min standing
interruptions;
3) active sitting on a stability ball.

14-18 YEAR OLD MALES WITH OVERWEIGHT/OBESITY
Experimental study with a cross-over design, including three experimental
conditions, lasting 5 hours each:
1) prolonged sitting on a lounge chair;
2) prolonged sitting on a lounge chair with 10-min standing interruptions every
30 min;
3) prolonged sitting on a lounge chair with 4-min cycling interruptions every
30 min, at a moderate intensity.

For details see document "C2. Amendement".

There are no expected risk or benefits in the present study. Participants will
visit the laboratory three times in a fasted state. After the first venous
blood sample is collected, they will receive a standardized meal. Venous blood
samples (6 samples in total) will be collected hourly using an in-dwelling
catheter. Additionally, autonomic functioning (non-invasive; pre, halfway,
post), attention/concentration (pre, halfway, post) and mood (hourly) will be
measured. Muscle activity will be measured hourly using surface electrodes at
the belly of the indicated muscles. These methods are safe, frequently used and
will be executed by trained and qualified researchers. The experimental
conditions include very common daily activities and do not possess any
potential risk either. There is minimal risk for the participants.
Nevertheless, vial broaching can induce pain for the participants.
Additionally, the time investment (5,5 * 6 hours per visit) can be a burden for
the participants.