The number of glucose molecules required to produce one molecule of ATP at aerobic level of exercise is a nett of 30. The number of glucose molecules required to produce on molecule of ATP at anaerobic level of exercise is 1. You can do anaerobic exercise for around two minutes before the lactic acid fatigue stops the muscles. You can keep riding all day at aerobic levels.
All-day long rides are OK, if that's what you want to do. But I don't know that many people who do them unless they are training for LD, setting out to achieve something like a century, or are touring.
Many training programs for LD riding suggest two or three short rides with relatively high intensity during the week, and one long one at the weekend. That is active training. There is nothing that says someone seeking health and fitness benefits has to do that, and there is nothing that says you have to ride if you don't find it fun to do.
I do have some trouble with some of the reports like those in the Examiner. I haven't followed the study to the journal, but I would suggest some care with a report written by someone who declares in passing their enthusiasm for one form of exercise regimen over another.
If you want to ride for beneficial purposes, ride as you want to. More importantly, watch what you eat. Apart from exercise, I think the other major active preventive measure for heart disease is looking carefully at what and how much you eat.
Link the two together, and you have a formula that seems to agree with the recommendations for adequate heart health.
FWIW...