Originally Posted by
wolfchild
Zone 2 is the best and most effective way to develop and maintain healthy mitochondria. This has already been studied and proven.
If it has been studied and “proven”, as claimed, please point to a published paper showing superior mitochondria development from zone 2 vs. other exercise intensities.
I doubt that even one such paper exists. Here are some key findings from a review paper (my underlines):
Training volume appears to be an important determinant of training-induced increases in
mitochondrial content (an effect that may be driven by training duration) whereas exercise intensity appears to be a key factor of training-induced increases in mitochondrial respiration.
High-intensity interval training at a relative exercise intensity ≥ 90% of the maximal power output provides the greatest absolute increase in mass-specific
mitochondrial respiration, whereas all-out
sprint interval training appears to be the
most efficient type of exercise to
improve mitochondrial respiratory function in terms of total training volume and/or time.
[I]t is plausible that to maximize improvements in mass-specific mitochondrial respiration an individual needs to
exercise at the highest relative exercise intensity that allows a large volume of training to be performed (e.g., ~90 to 95% of Ẇ ). This is consistent with previous recommendations regarding the type of training required to maximize improvements in VO2max and endurance performance.
Cesare Granata et al. Sports Med. 2018 Aug.
Notes:
- There is no suggestion that zone 2 training is special or more effective than higher intensity training. In fact, the paper suggests that a performance plateau is attained when doing zone 2, requiring harder training to produce further gains.
- Mitochondria content is the amount of mitochondria found in muscle.
- Mitochondria respiration is the amount of oxygen the mitochondria can process. This is the important thing for performance.
- To see the biggest gains, exercise as hard as you can while still completing a given volume.