Chemtai, a diminutive 27-year-old and a marathon novice, gained Israeli citizenship earlier this year through her coach, Dan Salpeter, after the two married in Kenya. They will be in Rio next month but a podium finish is not expected.
The unassuming athlete's inclusion in the Israeli team was confirmed only at the last minute after she was granted Israeli citizenship days before the deadline for her to be eligible to run for Israel.
It was a momentous day for Chemtai, who described the ceremony at which she was presented with her documents as "a great occasion".
"I am very proud (to represent Israel) and I hope to achieve a new personal best time," she told Reuters.
Chemtai, who grew up in a village in West Pokot County in western Kenya, had run shorter distances since her youth and took up the marathon only after the birth of the couple's son, Roy, who is 19 months old.
Despite a current personal best time of two hours, 40 minutes, which is far slower than the fastest runners, Chemtai's best is still ahead of her, said Salpeter.
"A personal best in Rio very much depends on the conditions, which can change from day to day, so it's hard to know ... But Lonah still has tremendous potential to improve greatly over the next 10 years and even beyond," Salpeter said.
