Increasing VO2 max increases how much power you can develop while remaining in aerobic respiration. This is great for cyclists, or anybody who needs to go literally as fast as possible for a few hours straight. But VO2 max is your "race car" mode, and training Zone 4 and VO2 max does not help your Zone 2.
For mountain climbers (like me), you do use Zone 4, but you want to spend as much time as you can in Zone 2. To achieve that, you have to train Zone 2.
What is Zone 2 good for? Hike with a park ranger. They can very nearly run up a mountain with a pack, without even breaking a sweat.
For mountain climbers (like me), you do use Zone 4, but you want to spend as much time as you can in Zone 2. To achieve that, you have to train Zone 2.
What is Zone 2 good for? Hike with a park ranger. They can very nearly run up a mountain with a pack, without even breaking a sweat.