Tag Archives: Muscle

Activity or Exercise? Do you know the difference?

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Exercise is the key to staying healthy.  Studies show that exercise is an important part of a healthy lifestyle because it reduces heart disease, cancer, depression, stroke and dementia to name just a few.  However, I find that most people do not know what exercise really is.  All too often they confuse it with activity.  Exercise and activity are cousins, but they are not the same thing.

In all of my new patient appointments I ask each person about their exercise habits.  Some people truly exercise, but the vast majority get no regular exercise. Still others think they exercise when in fact they are just active.  What’s the difference?

First, let me say that being active is without a doubt better than being a couch potato. However, it does not substitute for regular exercise.

So what exactly do I mean? Doesn’t being active mean I exercise? Not necessarily.

Here are the two scenarios I hear in my office the most.

The first is the busy mother of a small child.  Routinely they tell me, “I don’t need to exercise, I chase my small child around all day and pick him up and put him down.  That’s plenty of exercise.” Unfortunately that’s incorrect.  This person is active, but does not exercise and cannot possibly gain the benefits of exercise by looking after a small child.  Unless this mother is repeatedly picking up and putting down their child and squatting down over and over in a short period of time to do so and their heart rate is significantly elevated while doing so, they are not exercising.

Now, I understand that caring for a small child is tiring, but so is sitting at the library and doing research. Activities that make us tired do not always qualify as exercise.

The second scenario I hear most often in response to my question of exercise habits is actually one of two things; people will say, “I walk a few times per week,” or “I like to garden on the weekend.” Both of these again, are activities.  Very few people walk fast enough or the distances required for walking to be considered exercise.  I have one patient in particular who actually does walk far and fast enough for it to be exercise, but that’s a rarity.  Gardening will never be considered exercise.  Again, it may be tiring but two things disqualify it as exercise.  First, it does not increase the heart rate enough and second it is not done with enough regularity to be exercise.

Again, I want to stress that being active is a great start and is far superior to sitting on the couch and watching television.  But it’s just that – a start.

Exercise is something that drives heart rate, builds muscle and changes body composition. It should be done with regularity – at least 3 times per week for a minimum of 30 minutes.

I would ask you to consider this question; If you are a person who falls into one of the above scenarios and believe your lifestyle creates an environment in which you do not need to exercise because you are active consider this.

Are you happy with the results?

Are you tired and/or overweight despite chasing your small child around all day or gardening on the weekend?

If you answered no to the first question and yes to the second you should consider changing your point of view on what you consider exercise.

Remember, activity is a good thing. However, it is not exercise and cannot be used as a substitute.  I would encourage you to make time to exercise even if you are busy and active.  It will only help you in the end.

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Want a better brain? Lift Weights!

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Exercise has long been known to increase brain function.  Most of the research, however, focused on the benefits of purely cardiovascular exercises like running.  New research shows that weight training has the same effect.

Conventional wisdom has stated that the benefits of cardiovascular exercise on brain function was from the significant increase in blood flow to the brain during aerobic type exercises.  It was concluded that because weight training didn’t cause this to happen for extended periods of time, it would not have the same benefit.

The creation of new brain cells, or neurogenesis, is thought to be dependent on a spike of blood flow to the brain. In fact, running and other aerobic exercises have been shown to increase neuron production in the areas of the brain associated with memory and thinking in both mice and humans.  However, this was thought not to apply to resistance training.  That is changing.

“In a study presented at the annual meeting of the Society for Neuroscience in November, researchers from Brazil secured weights to the tails of a group of rats and had them climb a ladder five sessions a week. Other rats on the same schedule ran on a treadmill, and a third group just sat around. After eight weeks, the running rats had much higher levels of brain-derived neurotrophic factor (B.D.N.F.), a growth factor that is thought to help spark neurogenesis, than the sedentary rats. So did the rats with weights tied to their tails. The weight-­bearing rats, like the runners, did well on tests of rodent learning and memory, like rapidly negotiating a water maze. Both endurance and weight training seemed to make the rats smarter.” (From The NY Times)

A similar study from Japan at the same conference came to the same conclusions.

“The animals that were assigned to the loaded wheels showed significantly increased levels of gene activity and B.D.N.F. levels within their brains. The higher the workload the animals managed to complete, the greater the genetic activity within their brains.” (From The NY Times)

The genetic activity is important.  That’s precisely how the human brain adapts.  It changes the expression of certain genes in order to respond to certain environmental input.  That input may be in the form of exercise like weight training or it may be more cognitively based like learning to play the piano.  Whatever the input may be, the brain changes in response to the activity being performed.  This is a phenomenon called plasticity.  And the brain remains plastic our entire lives!  That means it can change right up to the day we die.

Just how does this resistance training increase brain function?  No one knows for sure, but there are theories.  The researchers propose that because weight training reduces many cardiovascular risk factors and does increase the strength of the heart it may also help the brain through similar mechanisms that aerobic exercise does.

I have another theory.  Ninety percent, yes that’s 90%, of the input that comes into our brains during any given day comes from the receptors in our muscles and joints.  That means that if we take into account all of the sensory input that our brains receive during the day – light, sound, touch, smell, proprioception – a full 90% of that input is coming from our muscles and joints.  If the body requires that much input from our musculoskeletal system it must be important, right?  It is.  This input keeps the brain functioning normally and maintains the health of just about every type of neuron in the brain.

Resistance training makes this input more efficient.  By training the muscles with weights they send more regulatory information to the brain and you also increase the amount of information coming from the joints.  The stronger your muscles the more force is applied through your joints.  This combination is a winning one in terms of brain function.

The best type of exercise program is one that includes both cardiovascular and resistance type training.  People are often hesitant to start a weight training program because of lack of knowledge on how to properly do it.  If you are concerned hire a knowledgeable trainer to show you how to do it.  The benefits will far outweigh your hesitance to start.

 

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Body Mass Index – Don’t pay any attention to it

The Body Mass Index, or BMI,  is used to ascertain whether someone is overweight, obese or at the correct weight for their height.  It’s used by health professionals across this country as a guide for their patient’s health.  It’s wrong.

The reason for this blog is a conversation I had with a good friend of mine.  He also happens to own a gym and is a very talented and knowledgeable trainer/fitness coach.  We were discussing it in relation to his clients and my patients and how people are often times misled by the numbers they see when they use the BMI scale.

BMI was designed to be used as an easy tool for clinicians to assess their patients in terms of body weight relative to height. Before the BMI scale was invented it was hard to assess someone’s weight and say that it was appropriate because height is also an important factor in weight.  BMI combined those two.

How to calculate BMI:

The formula is simple.  You need your weight in pounds and your height in inches.  Take your weight and multiply it by 703.  Take your height and multiply it by itself (height squared).  Now divide the first number by the second number and you have your BMI.  Here is an example.  We’ll use my numbers.  I am 201 pounds and 71 inches tall.

201 lbs x 703 = 141,303
71 in. x 71 in. = 5,041
141,303/5,041 = 28.03

So my BMI is just over 28.  This puts me in the overweight category, actually moving close to obesity.  Wait…what?

If you look below you can see the classification system used for BMI.

You will see that anything above 30 is considered obese.  Technically anything above 29.9 is obese.  If we use this scale, I am only 13-14 pounds short of being considered obese.  People who know me will tell you that I do not look obese.  They will also tell you that I do not even look overweight.  So what’s the catch?

That is the problem with using BMI to assess health.  It doesn’t take into account many factors.

The problem for some people, like athletes, it does not take into account muscle mass.  A person that is heavily muscled will always be overweight according to the BMI.  As a matter of fact, I have been considered “overweight” since college despite always being is relatively good shape.  If we look at professional level athletes, most of them would be considered obese!

I understand that not everyone is an elite athlete.  What about the elderly?  BMI is not ideal for them either.  Many times an elderly person will fit nicely into the BMI by being considered “ideal weight” for their height.  This can be significantly misleading.  Why?  In the elderly muscle mass begins to drop.  It happens to all of us.  However, with this drop in muscle mass comes a drop in weight.  As weight is lost a person is likely to fall into the “ideal weight” category even though they should be concerned about muscle mass loss.  This loss in muscle mass causes a loss in strength and stability increasing the risk of falls and increasing the risk of osteoporosis.  Another problem with muscle loss is the change in your body composition.  As muscle mass is lost one’s body fat percentage increases.  Body fat percentage is a great indicator of health.  The lower it is (within reason) the healthier you are, generally speaking.

So does it work for anyone?  Yes, there are some people that it works for.  If a person is sedentary and eats a poor diet it may accurately depict your current weight status (ideal, overweight or obese).  There are, however, better ways to assess health.

Then how do I know if my weight is appropriate?

The best way to assess your weight status is to perform body composition.  This gives us a percentage number based on body fat.  For example, if you weigh 200 lbs and 50lbs of that is from fat, your body fat is 25%.  Below is the ideal body fat percentages for men and women.

The gold standard for measuring it is the caliper test or skin fold test.  A pinch of skin is precisely measured by calipers at several standardized points on the body to determine the subcutaneous fat layer thickness. These measurements are converted to an estimated body fat percentage by an equation.  It is most reliable when taken over time and it must be done by the same person to be accurate.  Techniques can vary from person to person and may change the results.

The other way to measure it by bioelectrical impedance.  You are hooked up to electrodes that are spaced far apart on your body; usually on each hand or on a hand and a foot.  An electrical signal is passed between the electrodes and the resistance to the current flow is measured.  This is a painless process.  Fat and muscle have different resistance rates so the machine can estimate the body fat percentage based on that.  It is affected by hydration levels so be sure to be hydrated when you take a test like this.  This is a very accurate method and does not depend on a person’s technique as the skin fold test does.

The best way to get your body fat to the desired level is a healthy diet and exercise.  You want to increase muscle mass and decrease fat.  This is done by weight training and short duration, intense circuit type workouts.  All of this can easily be done at any local gym.

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