I having a feeling that although these sort of things should be expressed as absolute time rather than percentages. If you're running 10 hours a week then running 2 hard and 8 easy possibly makes sense. If you're running 2 hours a week then 2 hours hard is going to have a better training effect than the 20/80% combo of 24 minutes hard and 96 minutes easy. As the volume of exercise increases then the proportion that should be hard decreases, but at low volumes you have plenty of time to recover from each session.
The other thing to remember is that walking 26 miles is a different task to running 26 miles, But in cycling you could be putting out a power similar to walking, or one similar to running, and both would be classed as cycling.
Difficult one to compare, but I'd say they are very very roughly in the same ball-park. One of the things that makes it tricky to compare is that there's huge energy savings to be had riding in a group, compared to running in a group.