The Dunedin nurse qualified to compete in the world mountain running championships in Switzerland in September when she won the New Zealand title in April.
She also qualified for the world half-marathon in Brazil when she won the Buller event and came second to Olympian Nina Rillstone in the Christchurch half-marathon in June.
Her long-term goal is to compete in the marathon at the World Athletics Championships in Berlin in August next year.
"If I do the mountain race it will give me strength but it will also slow me down and make me take shorter strides," Crumpton said.
Crumpton (37) was encouraged to stay on the road after winning the women's section of the Gold Coast Marathon two weeks ago.
Her time of 2hr 38min 16min was the third-fastest of her career.
It also beat the International Amateur Athletics Federation's qualifying standard for the world championships by 5min.
This will be the fourth time Crumpton has competed at the world half-marathon championships.
She finished 29th in Mexico in 2000, sixth in Austria in 2002 and eighth in Italy in 2004.
Her best half-marathon time of 1hr 12min 58sec was run in Auckland in 2005.
The Gold Coast event was the first marathon run by Crumpton for two years since she failed to qualify for the 2006 Commonwealth Games in Canberra. There was a record entry of 21,000 runners competing in the Gold Coast marathon, half-marathon and walk.
This included 6000 in the marathon.
Crumpton has won nine of her 15 marathons, with a best time of 2hr 37min 3sec when finishing 33rd at the world championships in Helsinki in 2005, Since coming back to racing this year, Crumpton has also won the Buller half-marathon in 1hr 17min, been second to Olympian Nina Rillstone in the Christchurch half-marathon in 1hr 16min 38sec and won the Edmond Cup steeplechase at Wingatui. Crumpton will be racing in the Otago cross-country championships at Waikouaiti today.
