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by
Owen Anderson, Ph.D.
These 5 workouts will help you burn
more fat
Runners hoping to improve their performance (and their
overall health) by trimming body fat have two options. They can eat less fat
and/or total calories, or they can increase the rate at which they
metabolize fat during workouts. Since many runners are already either
watching their fat intake or unwilling to give up certain favorite foods,
the fat-burning approach is often more effective.
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.
Of course, if your current fitness doesn't permit you to run very far at 75
to 85 percent of MHR, you'll still reap weight-loss benefits if you do
longer workouts at lower intensities. With this in mind, we've created the
following five workouts--some fast, some slow--to help you maximize
fat-burning on the run.
These 5 workouts will help you burn
fat:
- If you have just 30 minutes for a workout, jog easily for 10 minutes
and then run at 85 percent of your MHR for the final 20 minutes (this is
approximately equivalent to your 10-mile race pace).
- For an hour-long workout, run at 75 to 80 percent of MHR
(approximately your marathon race pace).
- Once a week, run for 90 minutes at 70 to 75 percent of MHR (about a
minute per mile slower than your marathon race pace).
- Every two to three weeks, run for 2 hours in this manner: run 60
minutes at 75 percent of your MHR (slightly slower than your marathon race
pace), walk slowly for 15 minutes, then run 45 minutes more at about 75
percent of MHR.
- Once a month, wait 3 hours after eating dinner, then run for 60
minutes at 75 percent of your MHR. The next morning, before breakfast, run
another hour at 75 percent of MHR. The morning run will force your
carbohydrate-depleted body to burn extra fat.
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