Sufficient physical activity is essential for cardio-metabolic health and quality of life. However, inactivity and sedentary behavior such as sitting, which is associated to an array of health risks, is prevalent in our current way of living. Promotion of physical activity is therefore crucial.

Research into the promotion of physical activity has revealed that altering one’s lifestyle or losing excess weight can be challenging and is often accompanied by barriers. Practice nurses, physiotherapists and dieticians can provide support in making lifestyle changes. One of the combined strategies aimed at increasing physical activity is adding group sessions, however it is uncertain whether it positively enhances the effectiveness of lifestyle interventions. In order to define the effectiveness of intervention strategies, accurate measurement of physical activity is paramount for correct interpretation of study results. Several instruments exist to estimate physical activity levels, such as questionnaires and body-fixed activity monitors. When deciding which activity monitor to use in research and daily practice, popularity of a device is not necessarily the best option as it may not imply usability. Moreover, whether activity monitors can truly reflect the level of physical activity and sedentary behavior is still a subject of discussion.

The effectiveness of a multidisciplinary lifestyle program in increasing physical activity levels was evaluated in a study by Brenda Berendsen as part of her PhD thesis. The intervention was offered to 30 family practices across the Netherlands to more than 400 people by a team of nurses, physiotherapists and dieticians. In her PhD thesis defense, Brenda Berendsen presented distinct differences between activity monitors that were used in this study, these included the accuracy and ease of use. Three activity monitors were investigated: the CAM (forerunner of MOX, Maastricht Instruments), ActiGraphGT3X and ActivPal3. Results revealed that the differences in sitting, standing and time in motion was best represented by two monitors (CAM and ActivPAL3) that were worn on the thigh. Feedback from questionnaires on the CAM, ActiGraphGT3X and ActivPAL3 demonstrated that ActiGraphGT3X (46 x 33 x 15 mm; 19 g), worn around the waist, was very comfortable to wear. Participants found the CAM, which was the largest monitor (63 x 45 x 18 mm; 100 g), the most physically apparent while performing daily activities. With that consideration, Maastricht Instruments developed the MOX, a smaller monitor that is more compact and less obtrusive than the CAM.

Furthermore, Brenda Berendsen’s dissertation described the process and effectiveness of an intervention to encourage exercise and healthy diet in overweight people. In addition, the study showed that an intervention of a multidisciplinary lifestyle program was effective in increasing physical activity levels. However, an adequate amount of delivered therapy hours was required to benefit from the physical activity program.


brenda-berendsenBrenda Berendsen, PhD
Open University Heerlen, Department of Psychology and Educational Sciences

Brenda Berendsen defended her thesis “Measurement and promotion of physical activity: Evaluation of activity monitors and a multidisciplinary lifestyle intervention in primary care” on June 24, 2016 at 14.00 at the University of Maastricht. Download the article here.