Stellar evolution calculations have had great success reproducing the observed atmospheric properties of different classes of stars .
Recent detections of g-mode pulsations in evolved He burning stars allow a rare comparison of their internal structure with stellar models .
Asteroseismology of subdwarf B stars suggests convective cores of 0.22 - 0.28 M _ { \odot } , \gtrsim 45 \% of the total stellar mass .
Previous studies found significantly smaller convective core masses ( \lesssim 0.19 M _ { \odot } ) at a comparable evolutionary stage .

We evolved stellar models with MESA ( Modules for Experiments in Stellar Astrophysics ) to explore how well the interior structure inferred from asteroseismology can be reproduced by standard algorithms .
Our qualitative evolutionary paths , position in the \log g - T _ { eff } diagram and model timescales are consistent with previous results .
SdB masses from our full evolutionary sequences fall within the range of the empirical sdB mass distribution , but are nearly always lower than the median .

Using standard MLT with atomic diffusion we find convective core masses of \sim 0.17 - 0.18 M _ { \odot } , averaged over the entire sdB lifetime .
We can increase the convective core sizes to be as large as those inferred from asteroseismology , but only for extreme values of the overshoot parameter ( overshoot gives numerically unstable and physically unrealistic behavior at the boundary ) .
High resolution three-dimensional ( 3D ) simulations of turbulent convection in stars suggest that the Schwarzschild criterion for convective mixing sytematically underestimates the actual extent of mixing because a boundary layer forms . Accounting for this would decrease the errors in both sdB total and convective core masses .