14-year-old Jemina Koistinen runs marathon times in training

Jemina Koistinen, a 14-year-old from Kontiolahti, regularly runs marathon distances during training, a feat many adult runners only dream of, Yle reports.

Koistinen, an ultra-runner, has twice broken the Finnish under-19 record for six-hour runs. In April, she covered 60.082 kilometres in six hours at a competition in Kaarina, completing a marathon distance in just under four hours.

She approaches running analytically, considering it both a competitive sport and a hobby. While she trains ambitiously—sometimes running up to 100 kilometres a week—she maintains a balanced perspective, occasionally staying up late or taking lighter training periods during the school year.

Her mother and coach, Salla Ronkainen, considers ultra-running a relatively safe sport, noting that impact injuries common in team sports are rare in long-distance running. Ronkainen and Koistinen agree on training volumes, though Ronkainen sometimes reminds her daughter to rest.

Koistinen plans to compete in the 100-kilometre Masochist’s Dream race in August.