[David Meverden]

In case you check in again I'll throw out several points that help make sense of this:

1) High level crossfit athletes work for years to be able to handle a large workload.

2) A daily row/bike, can be added fairly easily as long as the intensity is low. An all out max effort 5k will have a significant recovery cost, but a nice easy 5k at 70% heart rate is easy to recover from. This type of regular low intensity work (cardio, essentially) is a great addition to develop an aerobic base and longer duration endurance, both of which are a necessary component for top CrossFitters.