Is the conventional wisdom that Zone 2 training is more efficient for running due to the higher caloric expenditure per hour accurate when comparing it to cycling, or are there other factors at play that could potentially make Zone 2 cycling a more effective way to build cardiovascular endurance and increase lactate threshold.
Some studies suggest that the lower impact nature of cycling could allow for longer periods of time spent in Zone 2 without the same level of muscle damage and recovery time required after running, potentially leading to greater overall training volume and increased cardiovascular adaptations.
However, others argue that the lack of eccentric loading and high-impact stress in cycling may limit the development of certain physiological adaptations, such as increased mitochondrial density and capillarization, that are thought to be important for endurance performance.
What are the thoughts on this topic, and are there any studies or data that can help to clarify the relative effectiveness of Zone 2 training for running versus cycling.