Intervals of 2-4 min in duration at 3-10k pace with 2-3 min recovery periods in between.
Typical sessions are :
4-8 x 800m or two sets of 6 x 400m with 30-60s and 2-3 min recovery in between intervals and sets.
This method is more specific for track runners than marathoners.
What is VO2 Max?
Source: Haugen et al., 2022