It does seem rather a shabby article. Out of all the ways we can imagine exercising, they compare 3 very mild approaches (plus not exercising) and someone proclaims one of them "the best"!?

If you want to find an "optimal" exercise, you'll need to specify a function you're trying to minimize. Might be time to run a marathon, or time to swim a mile in the ocean, or some blend of performance/hours_invested.

Of course, some people do this, e.g., folks trying to win Boston, etc. And even here, where the goal is clear cut, the absolute best approach is not at all obvious.