Nijmegen Exercise Study: the role of physical activity on the prevention of cardiovascular diseases

The relation between physical activity and health is well known and often
described. Inactivity increases the risk to develop chronic illnesses like,
cardiovascular disease, hypertension, stroke, osteoporosis and diabetes
mellitus. To prevent the development of these chronic illnesses, physical
activity is prescribed in all its ways: by physicians, radio, television,
newspapers and patient information. However, only 52% of the Dutch population
meets the guidelines for physical activity (the Nederlandse Norm Gezond
Bewegen). This national average is in contrast with participants of the
Nijmegen Four Days marches. Previous studies by the department of Physiology
showed that 92% of this unique population meets the physical activity
guidelines. Moreover, this group of subjects seems to be physically active
during the whole year, and most of them during their whole life.

This unique population enables us to assess the effect of a physically active
lifestyle on the prevention of cardiovascular and chronic diseases. Moreover,
we can determine whether it is beneficial to change to an active lifestyle
later in life, and the relation between physical activity and quality of life.
Whilst previous studies predominantly focused on a representative sample of the
general population, it is difficult to include enough subjects with an active
lifestyle. Alternatively, these studies compare the physical activity levels
between patient (and/or control) groups, or include subject at their current
activity level (while not correcting for their activity levels in the decades
before participation in the study). These approaches have important limitations
regarding their validity and extrapolation to the general population. Therefore
we will include participants of the Nijmegen Four Days Marches in which we can
obtain the intensity, frequenty and type of physical activity. Furthermore we
can obtain the physical activity levels for the past years, and the reasons why
a subject changed their lifestyle from inactive to active (potential in
combination with the diagnosis of a chronic disease).

The primary purpose of this study is to determine the relation between a
physically active lifestyle and the primary and secondary prevention of
diseases and death.

Using an online questionnaire, we will approach all civilian participants of
the Nijmegen Four Days Marches in 2011, which will be repeated annually during
the next 15 years.

In addition to the questionnaire, additional measurements are performed in a
subgroup of 9,600 subjects. These tests reveal important information regarding
risk factors for cardiovascular and metabolic diseases.

Obervational cohort study

The total cohort will receive an annual invitation to complete the online
questionnaire (20 minutes). The additional measurements in the subgroup
(anthropometric data, blood pressure, maximal handgrip exercise, walking
characteristics, blood drawing - 25 mL) have a minimal burden, physically as
well as in time, and provide important information which is necessary for the
primary aim of this study.