From 2005.
From the article:
To better understand the effects of differing amounts of exercise, the researchers studied 175 overweight sedentary men and women who were beginning to show signs of lipid problems. They were randomized into one of four groups: no exercise, low dose/moderate intensity (equivalent of 12 miles of walking per week), low dose/vigorous intensity (12 miles of jogging per week) or high dose/vigorous intensity (20 miles of jogging per week).
[…]
“On the other hand, participants who exercised at a level equivalent to 17 miles of jogging each week saw significant declines in visceral fat, subcutaneous abdominal fat and total abdominal fat,” Slentz continued. “While this may seem like a lot of exercise, our previously sedentary and overweight subjects were quite capable of doing this amount.”
Specifically, those participants exercising at the highest level saw a 6.9 percent decrease in visceral fat and a 7 percent decrease in subcutaneous fat.