Flat Half Marathons
Flat half-marathons courses are often the fastest races, and so are a great way of setting a new PB. Regular runners of the half-marathon distance (13.1 miles or 21.1km) often seek out flat courses for this purpose. The flattest courses tend to be in big cities, or along rivers and coastlines, where there isn't too much undulation. However, the flattest courses aren't always the fastest. There are other factors in play: crowded races and inclement weather can slow you down, or inspirational atmospheres and straight courses can improve time.