Aside from the many other benefits of running, burning fat / staying fit are prime motivators to getting us (the girls and I) off our sofas and on to the pavement.
It has been a constant battle to determine which burns more fat, running at the optimal "fat burning pace" which is generally slower than the "high intensity pace." Searching for answers, I came across the following article at Runner's World.
According to this, the numbers don't lie. You are better off running at a high intensity pace to burn more fat (yes! I am vindicated)!
"Many so-called "experts" recommend that the best way to burn more fat is to run slowly during workouts. You've probably heard advice about training in your "fat-burning zone," said to correspond to a heart rate of just 50 to 65 percent of maximum heart rate (MHR). This is equivalent to a running pace about 2 minutes per mile slower than your marathon race pace. In other words, very slow.
At first glance, such slow running seems like a great idea. A recent University of Texas study found that when athletes exercised at only 50 percent of their MHR, fat provided 90 percent of the calories burned. When the athletes sped up to 75 percent of MHR, fat provided "only" 60 percent of calories.
However, the higher-intensity session actually burned more total fat calories! This happened because the 50-percent workout burned only 7 calories per minute, while the 75-percent workout burned 14 calories per minute. A little simple math reveals that the harder workout consumed 8.4 fat calories per minute (60 percent of 14) versus just 6.3 fat calories (90 percent of 7) for the slow workout.
A study reported in last month's "Health Watch" column reached similar conclusions. In that intriguing experiment, world-famous fat researchers from Laval University in Quebec City, Quebec, reported that intense exercise led to a ninefold greater loss of body fat, per calorie burned, than less intense exercise. The scientists at Laval had earlier shown that vigorous exercisers are thinner than moderate exercisers who burn the same number of calories. From these studies, you might conclude that you should run at top speed to maximize your fat-burning potential. Not so. Above 85 percent of MHR, fat metabolism begins to drop. It appears that 75 to 85 percent of MHR is the ideal range for fat-burning."