Training: Office to Pekan Gurun

Yesterday i broke again my training PR for 8km. Last 2 weeks running from my office to pekan Gurun in fast pace clocked 42.48mins (11.04, 10.05, 10.39, 11.00). Yesterday after 3 days of rest, clocked 41.09mins (10.38, 9.35, 10.00, 10.54). Wow! 5.12 pace. Now i know what it takes/feel to do fast run. Usually i'm doing easy/comfortable pace in 5:30 or 6:00.