Sound bites suck.
Exercise keeps the heart healthy. Then it's like the song "There's a hole in the bottom of the sea". It's a big picture, not a sound bite.
The end of the attached article says...
"In short, it's what you eat, not how hard you try to work it off, that matters more in losing weight. You should exercise to improve your health, but be warned: fiery spurts of vigorous exercise could lead to weight gain."
The bolded part is obvious. If you eat what you usually eat, then work your ass off, you eat more because it makes you hungry. Ultimately you end up fatter.
Mark is exactly right when he said "The real key to weight loss is, after all, to take in less calories than you burn".
Gluttony and sloth are human conditions. I'm good at both. That's why I'm fat, not because I don't exercise, because I work my ass off.