They have completed hundreds of race miles over varying distances from 5km to 10-mile road races, off-road half marathons and the London Marathon, but an overnight 40-mile ultra marathon marked new territory.
After 40 miles of running, Sharon and Elaine finished only 10 seconds apart among the 98 runners who chose the 40-mile route.
Sharon completed the four laps of the 10-mile circuit through Grimsthorpe estate, near Bourne, was 45th in a time of 9hr 21min 55secs for 45th place, with Elaine crossing the line 47th in 9.22.05.
Louth Athletics Club member Lisa Harkness also took part and finished 49th in a time of 9.24.52.
A total of 15 runners successfully completed the 70-mile route and 25 finished the huge feat of 100 miles non-stop.