MOVE: October 2012

Ask our Staff - I know what my numbers are......but I am not sure how they stack up, where I should be, and how exercise helps?

Great question, and thanks for queuing this one up!  Let’s start with a little story....

I know a guy...let’s call him “Bob”....and “Bob” just got back from his annual physical with his doctor and was told, “Your numbers are borderline.  It’s really time to start exercising!”  But unfortunately the message that didn’t quite come clear was....why?... where should my numbers be?... how exactly do I get them there?... how much exercise should I do?....what types?....for how long?.....and, are you sure it will work? Maybe “Bob’s” story sounds pretty familiar?

It probably should.....we tend to talk to a lot of “Bobs”!...and rightfully so...exercise after all IS one of life’s great panaceas (woah...check out that vocab word)!  And while exercise has benefits that touch nearly all of the areas of health that we so often refer to: "physical health" (both body & brain function that we refer to as "physiological health"), "mental health" (self esteem, confidence, anti-depression, mindset, etc that we refer to as "psychological health"), "social health" (connectedness among friends, that we refer to as "sociological health") and even "spiritual health" (connectedness to a purpose or being bigger than self). For the purposes of this article, and to most directly answer your question - we’ll focus on the most concrete ways that exercise has been shown to impact “your numbers”.  For an overview on the “numbers” we choose to measure and why - check out this month’s ENDURE article.

Vitals

• Resting Heart Rate - it’s simple really, the body needs a certain amount of nutrients and oxygen, carried by the blood, and pumped by the heart.  The amount of blood the heart can pump is known as “stroke volume”.  If the heart, being a muscle, is strong, it can “pump” hard enough to produce enough stroke volume and supply the body the nutrients it needs with fewer pumps than if it is weak (and therefore needs to be run "faster").  Want to get the heart stronger....make it pump more frequently through frequent exercise bouts that (preferably at least 30 minutes each) total of at least 150-180 minutes weekly intensely enough to "break a sweat". As the heart gets stronger, the heart rate will often slow.

• Blood Pressure - the systolic (top number) is the amount of pressure on the artery walls while the heart contracts, while the diastolic (bottom number) is the amount of pressure when the heart relaxes, or in between contractions (think "re-filling").  There are almost too many benefits of exercise on BP to discuss, but similar to it’s effect on resting heart rate, when the heart is stronger it doesn't have to work as hard during each beat, thereby decreasing the amount of pressure required to push blood through the arteries.  In addition, as exercise lowers cholesterol and triglycerides, the likelihood of arterial narrowing decreases, logically leading to a larger “pipe” to push blood through, thereby decreasing the pressure in the “pipes”. Finally, as you exercise the demand from the working muscles increases and the body responds by relaxing the arteries allowing for a larger, more flexible pipe for blood to pass through......the more you "ask" the body to give you this temporary change, the more permanent it becomes.

Cholesterol

• HDL (High Density Lipoprotein) “The Good” - Research published by the American Heart Association suggests HDL cholesterol, produced in the liver, helps to form a protective oil like wall on the interior of the arteries, preventing blockages, and  “scrubbing” the interior walls of the arteries. It also cleans out excess LDL (bad) cholesterol, and transports it back to the liver where it is converted into bile and digested, or excreted from the body.  Most research links exercise as an effective method to cause the liver to produce more HDL cholesterol.  And while there are some studies that suggest all exercise forms can help in reducing bad cholesterol, most recent studies conducted and published by Duke University in 2002 suggest that longer duration and more intense aerobic-based exercise such as jogging, swimming, and cycling for at least 30-60 minutes on most (5-6) days per week have the greatest effect on raising HDL.

• LDL (Low Density Lipoprotein) “The Bad” - While we’ve covered some of the basics to lowering LDL through increased exercise above, new research is also indicating that exercise can actually increase the size of the protein particles that carry cholesterol through the blood (when the protein particles bind with cholesterol they form a “lipoprotein”).  And in this case, the bigger the better!  Small lipoproteins have proven much more dangerous as they can infiltrate the interior linings of the heart and blood vessels, while larger particles tend to remain on their “best behavior”

Triglycerides - are simply a three chain fatty acid, and the most common form of fat found in the body and food.  High triglycerides are most often a result of a lifestyle where one consumes more calories than one burns.  Energy not burned is then stored as fatty acids in adipose (fat) tissue, or in the blood.  The risk associated is that high triglycerides can lead to artherosclerosis (hardening) or narrowing of the arteries, causing less than adequate blood flow, and potential heart attack or stroke.  The American Heart Associations suggests that exercise, the most common and effective way to “increase” the burn of calories, for at least 150 minutes weekly can reduce blood triglycerides by 20-30%.

Blood Sugar (Glucose) - sugar (glucose / glycogen) is the primary fuel for the body’s muscle, however it relies on insulin to transport the glucose from the blood to the muscle.  Individuals with high blood sugar are most often referred to as “insulin resistant” meaning the insulin is unable to effectively transport glucose into the body’s muscle.  Research indicates that exercise increases the rate of glucose uptake by the contracting skeletal muscle.  Makes sense, right?  We use our muscles and burn up their fuel...they go to the body for more fuel.  Interestingly, resistance training of the larger muscle groups (legs, back / trunk, chest, shoulders) have shown increased benefit on maintaining a healthy blood sugar.

Weight / Body Composition / Body Fat - although there are some complexities, this one starts as simple math!  If we know that exercise helps us “burn” more energy in the form of calories, and we know that what we consume (with the exception of water) has a caloric value, if we burn more than we consume, our body must tap into it’s energy storage, aka fat.  Key points to keep in mind - although not an "exact" value at all times because of things like hormonal fluctuations and levels of insulin sensitivity (as listed above), 1 lb. of body fat stores the equivalent of 3,500 calories worth of energy, and the average person burns approximately 100 calories per 10-15 minutes of moderate to vigorous activity.  Or for you walkers / runners, approximately 100 calories per mile, it's just a question of how much "stored energy" you're looking to burn. One caution here though......people who attempt to exercise their way to a lean body (i.e. don't look closely at their nutrition) are OFTEN frustrated in this pursuit. To this end, we OFTEN (if not always) recommend taking a close look at your nutrition before you try to use exercise as your primary fat-loss strategy.

Are you “Normal”?
http://www.heart.org/HEARTORG/Conditions/Cholesterol/AboutCholesterol/Hyperlipidemia_UCM_434965_Article.jsp
http://www.mayoclinic.com/health/reduce-cholesterol/CL00012
http://www.webmd.com/cholesterol-management/features/exercise-to-lower-cholesterol
http://www.theheart.org/article/1214279.do
http://www.ncbi.nlm.nih.gov/pubmed/9509261
http://www.nlm.nih.gov/medlineplus/triglycerides.html
http://www.aanp.org/images/documents/education/ManagingYourTriglycerides.pdf

Written by Eric Eisenhart, CPT, PES.  Eric is a Partner and Director of Health & Fitness services with Pro-Activity.