Once you start eating a more
healthful diet and
exercising, you should start losing weight fairly quickly. Here are a few tools you
can use to track progress and gauge your effort as you work toward your
weight loss goals.
Body Mass Index
The Body Mass Index (BMI) is a common tool for determining whether your
weight is in the healthy range. BMI is a straightforward calculation based
on your height and weight. Here’s the exact formula:
In pounds:
[Your Weight in Pounds ÷ (Your Height in Inches)2] x 703
In metric:
Your Weight in Kilograms ÷ (Height in Meters)2
If you prefer, you can use an online calculator to help you
determine your BMI.
This is what your BMI number will tell you:
-
Underweight: BMI ≤ 18.5
-
Normal weight: BMI = 18.5–24.9
-
Overweight: BMI = 25–29.9
-
Obese: BMI ≥ 30
While BMI is a convenient starting point for measuring and assessing your
health relative to your weight, it isn’t enough on its own to give
you a clear picture of your health risks. That’s because not all
weight-to-height ratios reflect the same thing. For instance, a bodybuilder
may weigh the same as his couch-potato brother, but they’ll obviously
have different health risk profiles.
Recent research has shown that another measure—Waist to Hip Ratio
(WHR)—is a much more accurate predictor of health risks.
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Waist-to-Hip Ratio
Various studies have shown a direct connection between the diameter of
an individual’s waist and his or her risk of developing diabetes.
Numerous other studies have found that visceral fat, also known as abdominal
fat, is closely associated with diabetes,
high blood-fat levels, and
high blood pressure.
Based on this growing body of research about waist-to-hip ration (WHR),
the general recommendation has been for everyone to not worry so much
about losing weight but, instead, to concentrate on losing “waist.”
To find your own WHR, you need to measure very accurately. Here’s
the simple division for this ratio:
Your waist circumference measured at your belly button ÷ Your hip
circumference measured at the widest point
You can also find numerous
online calculators to help you determine your WHR. World health officials say men have too
much abdominal fat if their ratio is greater than 0.9. For women, the
cutoff number is 0.85.
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Target Heart Rate
To get the most from your aerobic exercise efforts, you should try to keep
your heart rate in the “target zone” while you’re exercising.
Finding your target heart rate takes a few quick calculations. First you
need to find your predicted maximum heart rate.
Predicted maximum heart rate. Your maximum heart rate (MHR) is the highest your pulse rate can get. For
practical purposes, we calculate a predicted maximum heart rate. To do
this, simply subtract your age from the number 220.
220 − Your Age = Predicted Maximum Heart Rate
Target heart rate. A normal target heart rate for aerobic exercise is between 60 to 80 percent
of the predicted maximum heart rate. To calculate this range, multiply
your predicted maximum heart rate by (.60) and then by (.80).
Predicted Maximum Heart Rate x (.60) = Low End of Target Heart Rate Range
Predicted Maximum Heart Rate x (.80) = High End of Target Heart Rate Range
You should never exercise above 85 percent of your maximum heart rate for
an extended period of time, and if you have any health conditions, check
with your doctor to see if your own exercise target heart rate should
be lower than the standard range.
Exercise heart rate. To find your actual heart rate during exercise, stop your aerobic exercise
and count your heartbeats. Do this by placing the tips of your index and
second fingers on your neck below your jaw line, on either side of your
windpipe. Press lightly until you can feel the blood pulsing under your
fingers. Using a watch with a second hand, count the beats you feel for
30 seconds and then multiply this number by two.
Number of pulse beats in 30 seconds x 2 = Exercise Heart Rate
If your exercise heart rate is below your target zone, you can increase
the intensity of your aerobic exercise. If it’s above your target
zone, then you need to decrease your exercise intensity.