- What is “aerobic base” (via the TR blog)
- The post in this thread from last August linking to more information about decoupling
tl;dr for aerobic base:
- Increased capillarization
- Increased mitochondrial proliferation
- Increased aerobic enzymes
- Increased cardiac output
- Increased fat metabolism
All of these adaptations coalesce to achieve a shared outcome, which is more oxygen extraction at the muscle.
tl;dr for decoupling:
[T]he limited research available appears to indicate that when aerobic endurance improves there is reduced heart rate drift relative to constant outputs (power and speed)…This parallel relationship between input (heart rate) and output (power or speed) is referred to as “coupling.” When they are no longer parallel in a workout as one variable remains steady while the other drifts the relationship is said to have “decoupled.” Excessive decoupling would indicate a lack of aerobic endurance fitness.