  Asteroseismic methods offer a means to investigate stellar activity and
activity cycles as well as to identify those properties of stars which are
crucial for the operation of stellar dynamos. With data from CoRoT and
\textit{Kepler}, signatures of magnetic activity have been found in the seismic
properties of a few dozen stars. Now, NASA's Transiting Exoplanet Survey
Satellite (TESS) mission offers the possibility to expand this, so far, rather
exclusive group of stars. This promises to deliver new insight into the
parameters that govern stellar magnetic activity as a function of stellar mass,
age, and rotation rate. We derive a new scaling relation for the amplitude of
the activity-related acoustic (p-mode) frequency shifts that can be expected
over a full stellar cycle. Building on a catalogue of synthetic TESS time
series, we use the shifts obtained from this relation and simulate the yield of
detectable frequency shifts in an extended TESS mission. We find that,
according to our scaling relation, we can expect to find significant p-mode
frequency shifts for a couple hundred main-sequence and early subgiant stars
and for a few thousand late subgiant and low-luminosity red giant stars.
