The oldest of the three, Henrik, now 28, first won the European 1,500-meters title in 2012. Six years later, Jakob, who turns 19 this month, won the 1,500- and 5,000-meter races at the European championships and, in July, set a new national record in the 5,000 meters. In between, Filip, 26, won the European 1,500-meter title in 2016 and still holds the Norwegian record in that distance. (The brothers are the second, third and fifth eldest of seven siblings.)
This outsize familial success attracted the attention of Leif Inge Tjelta, a professor of sports science at the University of Stavanger in Norway, who has long studied and worked with distance runners, including Grete Waitz, the nine-time New York City Marathon winner from Norway. About seven years ago, Dr. Tjelta began attending and taking notes at the Ingebrigtsens’ training sessions. He also spoke with the young men and their parents. Their father, Gjert, has coached his sons throughout their careers, although he never ran competitively.
For the new study, which was published this month in the International Journal of Sports Science and Coaching, Dr. Tjelta set out to analyze what, in particular, about the Ingebrigtsens and their lives and training might be most consequential for their medal haul.
Perhaps most obviously, he noted, the Ingebrigtsens trained with relatively light mileage when they were young. While some elite teenage runners aim to complete as many as 90 or more miles a week, the Ingebrigtsen boys ran about 45 to 50 miles a week before they turned 16 and, at the direction of their father-slash-coach, gradually increased that mileage over the course of the next few years, until they plateaued at about 95 to 100 miles a week when they turned 18.
Little of this mileage involved intervals when the runners were young, Dr. Tjelta also points out. Before they turned 16, their training runs primarily were long and continuous. After that point, their father began threading in frequent interval sessions, most involving intense, minutes-long speed bursts at about the pace at which the young men would run a 10,000-kilometer race. This pace is somewhat slower than that at which many elite runners complete most of their intervals, which might be closer to, for instance, their 3,000- or 1,500-meter time.