What is double threshold training
The short answer
Double threshold training means two controlled threshold sessions on the same day, one in the morning and one in the evening, usually six to eight hours apart. Both stay at the same moderate intensity, a blood lactate of about 2 to 3 mmol/L. Elite runners do it on two days a week, with easy running in between. It is the core of the Norwegian method developed by Marius Bakken.
The logic is simple. A threshold session builds the most when it is long, but a long session at threshold piles up fatigue and the pace drifts too fast. Split the same work into two sessions with a break in the middle and you can do more of it, at the right intensity, and still recover for the next one. Bakken describes it as one long session with a long break in the middle.
The intensity: the Golden Zone
Everything depends on staying in the right zone. Bakken's targets:
- Lactate: 2 to 3 mmol/L for both sessions, with 2.3 to 3.0 as the "Golden Zone". If lactate drifts above 3 by the last rep of the morning session, the session was too fast.
- Heart rate: roughly 80 to 87 percent of max heart rate for well-trained runners.
- Feel: controlled. Hard enough to adapt, easy enough to repeat in the evening and again two days later.
The textbook threshold is 4 mmol/L. Bakken found that his own threshold, and that of many Kenyan runners he tested, sat lower. That is the whole point: the method works below the edge, not at it.
The classic mistake
Running threshold too fast. Most runners who try threshold work either slow down too much or push into hard intervals and collect fatigue they cannot recover from. The method only works when the speed limit is respected.
What a double threshold day looks like
| Session | Typical content |
|---|---|
| Morning | Longer reps, about 6 to 10 minutes, for example 2000 m or 3000 m repeats, at the low end of the zone. |
| Evening | Shorter reps, 400 m to 1000 m, or 1-minute reps with 30 seconds rest, or 45 seconds with 15 seconds rest. |
| Between reps | Short, functional rest that keeps lactate in range. |
| Gap | About 6 to 8 hours. Shorter loses some of the benefit, longer than 8 to 10 hours and the two stop working as one block. |
The evening reps are shorter, so their pace is a little quicker, typically 15 to 20 seconds per kilometre, while lactate stays the same.