  In Phys. Rev. D 102, 024057 (2020), the authors studied energy conditions in
$f(Q)$ theory following the same path as researchers handled the energy
conditions in the curvature-based modified gravity theories, like $f(R)$ or
$f(R,G)$ theories. However, the field equations in the $f(Q)$ theory was not
expressed as an effective theory in the literature earlier and in the above
mentioned paper [1], the authors claimed that the pressure and energy density
follow a set of energy condition criteria without showing how they came to this
conclusion. In this comment, we express $f(Q)$ theory as an effective theory in
Friedmann-Lema\^{i}tre-Robertson-Walker (FLRW) universe. And from there, the
correct energy conditions are obtained in the traditional (general
relativistic) way. Unfortunately, some missing terms in the published work [1]
are noticed.
