\"Does Your Basal Metabolic Rate Decline As You Age?\"
"Does Your Basal Metabolic Rate Decline As You Age?"
As they age, people are generally less physically active. The
result is that they burn fewer calories each day. Unless they eat
less to compensate for this reduction in calorie expenditure,
weight gain is the inevitable result.
It's also true that your basal metabolic rate — the number of
calories your body burns each day just to stay alive — tends to
drop as you age. According to conventional wisdom, this is
because you lose a small amount of muscle each year.
As a rule of thumb, the more muscle you have, the higher your
basal metabolic rate. However, many people don't realize that
muscle mass is not the only thing that affects your basal
metabolic rate. A little-known concept called energy flux also
plays a vital role in determining how many calories you burn each
Studies show that your metabolic rate declines with age
independently of muscle loss. In other words, young physically
active men tend to have a higher metabolic rate than their older
counterparts, even if they have the same amount of muscle.
The age-related decline in metabolic rate — even when muscle mass
is taken into account — is down to two reasons.
- Firstly, there's a strong link between exercise volume and your
metabolic rate. In other words, the more exercise you do, the
higher your metabolic rate. The fact that exercise volume
declines with age could be responsible for the drop in metabolic
- Second, metabolic rate is also linked to total calorie intake.
This means that the more you eat, the higher your metabolic rate.
A reduced metabolic rate in older physically active men could be
due to the fact they eat less than their younger counterparts.
Some evidence for this comes from a research group based at the
University of Colorado. They compared a group of young and older
inactive men with physically active men of a similar age.
Even when differences in muscle mass between young and old
subjects were taken into account, basal metabolic rate was lower
with age in both the inactive and physically active subjects. The
older men burned around 64-68 calories per hour, compared to
72-77 calories per hour in the younger subjects.
However, when researchers compared older and younger subjects
doing the same amount of exercise and/or eating the same number
of calories, there was no difference in basal metabolic rate.
The same holds true in women as well as men. Research comparing
premenopausal and postmenopausal women shows that basal metabolic
rate — again adjusted for age-related muscle loss — was roughly
10% lower in postmenopausal women who perform no exercise. In
contrast, there was no difference in metabolic rate between
premenopausal and postmenopausal distance runners and swimmers.
The link between adjusted basal metabolic rate, exercise volume,
and energy intake involves a concept known as energy flux, which
refers to the flow of calories (or energy) through your body.
A high energy flux means that you're eating a large number of
calories, but balancing that with an equally high volume of
exercise. A good example of someone with a high energy flux would
be a cyclist taking part in the Tour de France.
Despite the fact these athletes eat thousands of calories each
day, they're still able to remain lean simply because they're
doing so much exercise. An example of a low energy flux would be
someone following an extremely low-calorie diet while doing
little or no exercise.
The link between energy flux and metabolic rate holds true no
matter what your age. Young endurance-trained males, for example,
in a high state of energy flux have a higher metabolic rate
compared with a low energy flux state.
The bottom line is that you can minimize the age-related drop in
basal metabolic rate by maintaining a high energy flux —
balancing a higher calorie intake with an equally high volume of
exercise. Not only will this help you to stay lean, it's also a
great way to provide your body with more of the vitamins,
minerals and other nutrients it needs to stay healthy.
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good article and interesting read.
(krypto - you always post great articles! [img]/forum/images/graemlins/smile.gif[/img])
Yep ...it is definitely harder as you get older ....things just sit differently as you age .... but that doesn't mean you can't do anything about it. I am in better shape now than I have been for 15 years ...admittedly its not a perfect body ...but exercise (especially weights) really make a difference.