Zone 2 has lots of things going for it:

1. It's pleasurable.
2. It burns calories.
3. It helps you with your tan.
4. It gives you something to do between harder training days.
5. It lets you chat away with your riding buddies.
6. It gets your body accustomed to lots of time in the same position.

Is it the *optimal* way to make you stronger or faster or more efficient?

• increased plasma volume: no
• increased mitochondria: no
• increased lactate threshold: no
• increased muscle glycogen storage: no
• hypertrophy of type 1 muscle: no
• muscle capillarization: no
• increased VO2max: no