Background:
The evidence has showed that increasing physical activity is a particularly important element not only in prevention but also in the treatment of obesity. This study aimed to examine whether the use of accelerometers for monitoring physical activity is a sufficient motivator to adhere the recommended level of physical activity.

Material and methods:
The prospective study involved 44 obese children and adolescents aged 5 to 17 who were registered with the Pediatric Nephrology Department at the Medical University of Bialystok, Poland. Participants had to wear a device for at least 12 hours per day for 56 consecutive days. Anthropometric measurements were made at the beginning of the study and after eight weeks of physical activity monitoring.

Results:
The presented study results far exceeded the recommended amount of the average physical activity energy expenditure of young patients in the first two weeks. In the following weeks, the amount of daily energy expenditure gradually diminished, but finally, the average BMI Z-score was reduced from 2.80±0.64 at baseline to 2.48±0.27 at the end of the study (p<0.0147).

Conclusions:
The study demonstrates that tracking of physical activity may be an essential factor to improve compliance with physical activity recommendations.