  Using the zero-temperature Metropolis dynamics, the time decay of the
remanent magnetization in the $\pm J$ Edward-Anderson spin glass model with a
uniform random distribution of ferromagnetic and antiferromagnetic interactions
has been investigated. Starting from the saturation, the magnetization per spin
$m$ reveals a slow decrease with time, which can be approximated by a power
law:$m(t)=m_{\infty}+ ({t\over a_{0}})^{a_{1}}$, $a_{1} < 0$. Moreover, its
relaxation does not lead it into one of the ground states, and therefore the
system is trapped in metastable isoenergetic microstates remaining magnetized.
Such behaviour is discussed in terms of a random walk the system performs on
its available configuration space.
