ues per epoch (e.g. 5 seconds). Aside from
harmonising the data across studies, aggregation per epoch also has
other advantages:</p>
<ul>
<li>Evidence on the value of accelerometer data is based on epoch-level
aggregates, because reference values like Oxygen consumption or sleep
cannot reliably be derived at sub-second resolution.</li>
<li>Aggregating leads to less data points which makes it a lot more
practical to work with.</li>
</ul>
<p>In GGIR, the epoch length is kept constant across the GGIR parts to