-- Phase 3 ( Weeks 17 - 21 ) tapering distances so as to keep working .
-- Phase 3 ( Weeks 17 - 21 ) tapering distances so as ultimately to feel fresh , confident and injury free for the 100 mile ultramarathon .
-- Phase 3 ( Weeks 17 - 21 ) tapering distances so as to keep working but ultimately to feel fresh , confident and injury free for the 100 mile ultramarathon .