Pros and cons
Pros
- Provides an objective measure of total physical activity
- Gives a detailed description of activity patterns
- Devices have reasonable data storage capacity (7-28 days monitoring at 1-min epoch resolution)
- The method has been extensively validated
- Shown to have high validity compared to indirect calorimetry in the lab with correlations of r=0.8-0.9
- Acceptable validity at group level when compared to indirect calorimetry measured in the field with correlations of r=0.4-0.6; higher correlations (r=0.63-0.8) have been shown using Tracmor (Philips) accelerometer (Plasqui et al, 2005) which is not yet commercially available
- Able to detect change in activity
- Unlikely to induce a large change in behaviour due to the process of measurement
- Relatively cheap compared to combined sensors
- Low participant burden
- Suitable for use across all age groups
Cons
- A single-mounted accelerometer is unable to measure all activity e.g. upper body, cycling and carrying loads
- The amount of data produced from accelerometry requires some skill to process and interpret
- Confusion about estimating energy expenditure due to the large number of prediction equations available
- Compliance may differ according to where the accelerometer is attached and may be low in some populations, e.g. adolescents
- Can be expensive and quite labour-intensive for initialising, downloading, recharging and (technically) servicing monitors