How it works
Spend a lot of time right at the edge where lactate starts to accumulate (LT2) without tipping over it. Held under control, this intensity drives strong aerobic adaptation and stays repeatable. Stay just below the line.
The Norwegian double-threshold twist
Pioneered by Marius Bakken and popularized by Jakob Ingebrigtsen and the Norwegian triathletes, the method runs two sub-threshold sessions in one day. Blood lactate is measured between intervals to keep each rep just below LT2, so the athlete accumulates a very high weekly volume of quality work.
How to apply it
Most amateurs cannot do this literally. It needs a lactate meter and the recovery for big volume. Borrow the principle: run threshold intervals at a pace you could just hold for an hour, do not push harder, and keep the rest of the week easy.
FAQ
What is the lactate threshold (LT2)?
LT2 is the intensity above which blood lactate rises faster than your body can clear it. It sits close to the hardest steady effort you could hold for about an hour, and it anchors threshold training.
Do I need a lactate meter to train this way?
To follow the Norwegian method literally, yes, because each rep must stay just below LT2. Without a lactate meter, approximate the zone with heart rate or pace and aim for a controlled, comfortably hard effort.
Is double-threshold training right for beginners?
Double-threshold training is not for beginners. Two quality sessions in a day demand high fitness, careful fueling and real recovery. A beginner gains more from one controlled threshold session per week plus easy running.