  Results for the isovector axial form factors of the proton from a lattice QCD
calculation are presented for both point-split and local currents. They are
obtained on a quenched $16^{3} \times 24$ lattice at $\beta= 6.0$ with Wilson
fermions for a range of quark masses from strange to charm. We determine the
finite lattice renormalization for both the local and point-split currents of
heavy quarks. Results extrapolated to the chiral limit show that the $q^2$
dependence of the axial form factor agrees reasonably well with experiment. The
axial coupling constant $g_A$ calculated for the local and the point-split
currents is about 6\% and 12\% smaller than the experimental value
respectively.
