THE SECRET TO SPEED IS IN YOUP BLOOD

Some of the world's best runners credit this unorthodox Norwegian training method for their success. Is it right for you?

- A. C. SHILTON

IN THE PILOT episode of the 2016 reality docuseries Team Ingebrigtsen - Norway's answer to Keeping Up With the Kardashians, except, of course, that no one can keep up with the family of runners - Gjert Ingebrigtsen has his teenage sons perform a set of 1000-metre repeats in the dark of night. They pause after each to prick their fingers for blood samples.

Since the series aired, Jakob, now 23, has shot to stardom, becoming a two-time world champion, winning Olympic gold in the 1500 at the Tokyo games, and breaking the 2-mile (3.2km) world record in June 2023. His older brothers, Henrik and Filip, both had successful track careers, too. The credit isn't purely genetic - it's also the result of an unconventional training regimen implemented by their father. (As of 2022, Gjert Ingebrigtsen no longer coaches his sons; and in late 2023, Jakob, Henrik, and Filip published an op-ed in the Norwegian newspaper VG accusing him of physical violence and threats. Gjert Ingebrigtsen has denied the allegations.)

One aspect of this regimen is regular blood-lactate testing (yup, with a needle) and running intervals at an intensity low enough to keep too much lactate from accruing. While blood testing is an accurate way to measure lactate threshold, it's also pretty invasive, and it's uncomfortable. With very few exceptions, it's not a standard or regular training tool for elite endurance athletes.

WHAT IF YOU COULD GET THE BENEFITS OF FASTER RUNNING WITHOUT THE WEAR AND TEAR?

The technique, attributed to former elite Norwegian runner Dr Marius Bakken, is known as Norwegian lactate-guided double-threshold training, a mouthful of a name that speaks to its main features: the idea that running right below the lactate threshold - as determined by on-the-spot blood testing - provides the most benefit, and that it requires two workouts in one day.

It's hard to argue with the Ingebrigtsens' results.