Current physical activity recommendations (PAR) for Irish adults are to achieve a minimum of 150 mins/wk of at least moderate intensity physical activity (MPA) or 75 mins/wk of vigorous physical activity (VPA)^{( 1 )}. Typically PA levels which are determined using activity questionnaires are prone to misreporting and are inconsistent in validity and reliability⁽ Reference Livingstone ^{2 )}. However, data collected using accelerometers provide an objective measure of PA, as well as information on frequency, intensity and time spent in PA. The aim of this study is to describe PA patterns in Irish adults.

A nationally representative group of Irish adults^{( 3 )} (n=1111, 18–85 yrs) wore a uni-axial accelerometer (Actigraph, GTM1) for 4 consecutive days. Time spent in moderate and vigorous PA (MVPA) was determined using cut-offs⁽ Reference Freedson ^{4 )} and was normalised to give weekly estimates of PA. Anthropometric measures of weight and height were also performed and BMI (kg/m²) was calculated. Fat mass (kg) determined by bio-electrical impedance, was adjusted for height (fat mass index FMI, kg/m²) and expressed relative to total body weight (%).

Removal of non-wear times resulted in complete accelerometry data (≥600 mins/d for 2 to 4 days) for n=849 subjects. There were no significant differences between those with complete accelerometer and those without complete data (weight, age or BMI P>0.05) apart from height (1.68 m vs. 1.7 P=0.045).

BMI, body mass index; FMI, fat mass index; MVPA, moderate and vigorous physical activity; PAR, physical activity recommendation. Median values were significantly different from those Below PAR (Mann Whitney U test) *P<0.05, **P<0.01.

Approximately 88% of Irish males and females met the weekly PAR. Those who met the PAR had significantly lower BMI and fat mass (%, kg) and FMI. Further analysis of these data will allow for more complete understanding of the relationship between body composition and PA in Irish adults.