Runners who want to snag early bird discounts have until next Thursday to sign up for the 2018 Standard Chartered Singapore Marathon (SCSM), with almost 25,000 having registered as of Wednesday.

The 17th edition of the race will take place over Dec 8-9 this year in a new two-day format featuring six categories.

Making a return is the 5km category, which joins the existing marathon (42.195km), half-marathon (21km), 10km, Ekiden and Kids Dash categories.

Participants looking for an entry-level distance but full marathon experience are encouraged to join this category, which will be flagged off together with the 10km.

The race will begin at the F1 Pit Building and end by The Float at Marina Bay on Dec 8, a day before the marathon and half-marathon.

Those unsure of which category to sign up for can take up the Double-Up Challenge, providing them access to either the 5km or 10km on the Saturday, before proceeding to participate in either the half or the full marathon on the Sunday.

Last year's race attracted 48,400 participants. The marathon category was won by Kenyan Cosmas Kimutai in 2hr 22min 48sec.

Soh Rui Yong (2:35:55) and Rachel See (3:11:08) were the fastest Singaporean man and woman respectively, with the SCSM also doubling up as the national championships for the first time after a tie-up between Singapore Athletics and organiser Ironman Asia.

The SCSM has been an International Association of Athletics Federations Gold Label race since 2012.

•Visit www.singaporemarathon.com for more information.