*How to activate your lazy fat and move your muscle molecules?
The influence of exercise training on RNA expression in adipose tissue and skeletal muscle in obese humans*

Presence of low-grade chronic inflammatory is suggested to be a key factor in
the development of the metabolic syndrome in subjects with obesity.1, 2 By
secreting pro-inflammatory cytokines and adipokines, adipose tissue exerts
paracrine and endocrine effects in multiple target tissues, such as skeletal
muscle and the liver. This has direct effects on glucose homeostasis and plays
a key role in the development of insulin resistance and cardiovascular
disease.2, 3
Exercise training has been proven to be a powerful lifestyle intervention to
improve insulin sensitivity and other components of the metabolic syndrome and
cardiovascular risk factors.4 Benefits of exercise training cannot be simply
explained by changes in body weight. To explain improvements in metabolic
function and cardiovascular risk factors after exercise training, analysis of
molecular changes in these tissues is paramount.5 Whilst most previous studies
focused on skeletal muscle, relatively little is known about potential
molecular changes in adipose tissue in response to an exercise training.5-7
Therefore, the first aim is to study effects of 8-week exercise training on RNA
expression profiles in adipose tissue and skeletal muscle in obese subjects,
and subsequently relate these changes to exercise-induced improvement in
insulin sensitivity and cardiovascular function.

The primary aim for this study therefore is:
1. To study the effects of an 8-week exercise training on RNA expression
profiles in adipose tissue and skeletal muscle in obese individuals
Secondarily we also aim:
2. To relate changes in RNA expression profiles in adipose tissue and skeletal
muscle in to adaptations in metabolic and cardiovascular function in response
to exercise training.

Single-center intervention study

8-week exercise training intervention

Performance of a subcutaneous fat or muscle biopsy is not associated with an
important health risk.8 Complications include infection, bleeding and hematoma
formation (<2%), whilst these complications will resolve within 2 weeks. The
biopsy procedures do not induce discomfort and/or functional impairment. After
the muscle biopsy, subjects are not allowed to perform exercise during 12 hours
and will be instructed not to take a bath for 48 hours. During the
hyperinsulemic, euglycemic clamp, two venous catheters are placed in veins of
arms of the subjects. Venous catheterization can induce a hematoma (<5%).
However, this is completely reversible within 2 weeks and will not induce
permanent damage. Taken together, the nature and extent of burden and risks
associated with the different measurements are modest