I am not the fastest runner (I only started taking it seriously after I dislocated my shoulder, here), but I love the activity. Anyhow, here are the three routes I usually take around the National University of Singapore (NUS).
1. King Albert Park (10.7km)
University Town > King Albert Park (Clementi Road, U-Turn) > Singapore Polytechnic (Commonwealth Ave West) > University Town (Dover Road)
2. West Coast Park (9km)
University Town > West Coast Park (Clementi Road, within the park, U-Turn) > University Town
3. National University Hospital (6.5km)
University Town > Fusionopolis (Dover Road, Ayer Rajah Ave) > National University Hospital (South Buona Vista Road) > Behind National University Hospital (Kent Ridge Road) > Central Library > University Town