The Grim Reaper prefers to walk at 0.82 m/s (2 miles (about 3 km) per hour), with a maximum estimated speed of 1.36 m/s (3 miles (about 5 km) per hour)
Older men wishing to outrun the Grim Reaper should maintain walking speeds above these levels
Here's the full study: http://www.bmj.com/content/343/bmj.d7679
So keep walking everybody!
BTW, since the reaper is traditionally depicted as having only a cloak and a scythe, he is obviously an ultralight bushwalker...

Cheers,
Alliecat