Who Needs Medical Clearance Before Starting an Exercise Program?

medical clearance, treadmill stress test

This treadmill stress test is looking for hidden heart disease

To protect yourself from injury, I suggest that you obtain “medical clearance” from a personal physician before starting an exercise program. A physician is in the best position to determine if your plans are safe for you, thereby avoiding complications such as injury and death.

Nevertheless, most adults can start a moderate-intensity exercise program with little risk. An example of moderate intensity would be walking briskly (3–4 mph or 4.8–6.4 km/h) for 30 minutes daily.

Men over 40 and women over 50 who anticipate a more vigorous program should consult a physician to ensure safety. The physician may well recommend diagnostic blood work, an electrocardiogram (heart electrical tracing), and an exercise stress test (often on a treadmill). The goal is not to generate fees for the doctor, but to find the occasional person for whom exercise will be dangerous, if not fatal. Those who drop dead at the start of a vigorous exercise program often have an undiagnosed heart condition, such as blockages in the arteries that supply the heart muscle. The doctor will also look for other dangerous undiagnosed “silent” conditions, such as leaky heart valves, hereditary heart conditions, aneurysms, extremely high blood pressure, and severe diabetes.

She looks healthy enough, but how can you be sure?

She looks healthy enough, but how can you be sure?

The American Diabetes Association’s Standards of Care state that routine testing of all diabetics for heart artery blockages before an exercise program is not recommended; the doctor should use judgment case-by-case. Many diabetics (and their doctors) are unaware that they already have “silent” coronary artery disease (CAD). CAD is defined by blocked or clogged heart arteries, which reduced the blood flow to the hard-working heart muscle. Your heart pumps 100,000 times a day, every day, for years without rest. CAD raises the odds of fainting, heart attack, or sudden death during strenuous exercise. I recommend a cardiac stress test (or the equivalent) to all diabetics prior to moderate or vigorous exercise programs, particularly if over 40 years old. CAD can thus be diagnosed and treated before complications arise. Ask your personal physician for her opinion.

Regardless of age and diabetes, other folks who may benefit from a medical consultation before starting an exercise program include those with known high blood pressure, high cholesterol, joint problems (e.g., arthritis, degenerated discs), neurologic problems, poor circulation, lung disease, or any other significant chronic medical condition. Also be sure to check with a doctor first if you’ve been experiencing chest pains, palpitations, dizziness, fainting spells, headaches, frequent urination, or any unusual symptoms (particularly during exertion).

Physicians, physiatrists, physical therapists, and exercise physiologists can also be helpful in design of a safe, effective exercise program for those with established chronic medical conditions.

Steve Parker, M.D.

Protect Your Aging Hippocampus (and Memory) With Exercise

…according to an article at MedPageToday. The 317 study participants were at high risk of Alzheimer’s dementia due to family history. The protective dose of exercise was at least 7.7 MET per hour/week. Please comment if you can translate that into something practical!

Retiring Later May Protect Against Alzheimers Dementia

…according to an article at MedPageToday. Use it or lose it?

Will You Have Regrets on Your Death Bed?

A palliative care nurse asked dying patients what they would have done differently when they had the chance:

1. I wish I’d had the courage to live a life true to myself, not the life others expected of me.

2. I wish I hadn’t worked so hard.

3. I wish I’d had the courage to express my feelings.

4. I wish I had stayed in touch with my friends.

5. I wish that I had let myself be happier.

Read the rest. While you still have your health and time.

Is mTORC1 Modulation the Key To Diseases of Civilization?

Was Hippocrates the dude that said something about “make food your medicine”?

Bodo Melnik has an article in DermatoEndocrinology regarding the dietary causes of acne.  He also comments on the role of Western foods in obesity, cancer, diabetes, high blood pressure, and neurodegenerative disorders.  These are our old friends, the “diseases of civilization.”  Melnik mentions the Paleolithic diet favorably.

Melnik says it’s all tied in with mTORC1: mammalian target of rapamycin complex 1.

A snippet:

These new insights into Western diet-mediated mTORC1-hyperactivity provide a rational basis for dietary intervention in acne by attenuating mTORC1 signaling by reducing (1) total energy intake, (2) hyperglycemic carbohydrates, (3) insulinotropic dairy proteins and (4) leucine-rich meat and dairy proteins. The necessary dietary changes are opposed to the evolution of industrialized food and fast food distribution of Westernized countries. An attenuation of mTORC1 signaling is only possible by increasing the consumption of vegetables and fruit, the major components of vegan or Paleolithic diets. The dermatologist bears a tremendous responsibility for his young acne patients who should be advised to modify their dietary habits in order to reduce activating stimuli of mTORC1, not only to improve acne but to prevent the harmful and expensive march to other mTORC1-related chronic diseases later in life.

You sciencey types can read the rest.  Our new friend mTOR also seems to be involved with growth of muscle induced by resistance exercise.

h/t Mangan

High Blood Levels of Omega-3 Fatty Acids Linked to Prostate Cancer

…increasing the risk by almost 50%. Click for details.

Darrin Carlson Recommends Basic Measuring Devices for the Neophyte Cook

…at The Guy Can Cook. Volume and weight measuring devices, thermometers, etc. Well worth a read if you’re new to cooking. If you’re trying to lose excess weight and keep it off, you need to be cooking at home more than the average person. Darrin writes: 

It’s easy to romanticize the image of the chef who does every thing by instinct.

He knows just how much ingredients to add, how long to cook it, and the exact moment that it’s done.

But we mere mortals are different, and there’s no need to bash our heads against the wall while we consistently ruin dishes that could have been saved with just a bit of science.

In this context, “science” means measuring devices.

Too Much Mouse and Molecular Biochemistry!

That’s my primary assessment of an article I read in Current Opinion on Clinical Nutrition and Metabolic Care.  The title is “Low-carbohydrate ketogenic diets, glucose homeostasis, and nonalcoholic fatty liver disease.”

Don't assume mouse physiology is the same as human's

Don’t assume mouse physiology is the same as human’s

The article’s more about mice than my patients.

The authors share some stats about nonalcoholic fatty liver disease (NAFLD):

  • the earliest stage is fat build-up in the liver
  • 15% of the nonobese population has NAFLD
  • 65% of the obese have NAFLD
  • it can progress to an inflammatory disorder (nonalcoholic steatohepatitis (NASH)
  • about two out of 10 NASH patients progress to cirrhosis within 10 years
  • NAFLD is an independent predictor of heart and vascular disease, an even stronger predictor than overall body fat mass (even visceral fat)
  • insulin resistance is strongly linked to NAFLD

The Washington University School of Medicine authors say good things about low-carbohydrate ketogenic diets for weight loss and seizure control.  They spend the rest of the article talking about rodent physiology and lab chows—right up Carbsane Evelyn‘s alley.  But not mine.  Bores me to tears.

They do mention the small Browning study that showed a very-low-carb ketogenic diet superior to a calorie-restricted diet for reducing liver fat in humans. Weight loss by various methods is a standard recommendation for humans with NAFLD; I wouldn’t be surprised multiple different diets worked.  It may be the weight loss, not the diet, that does the trick.  We have just one human study thus far indicating a ketogenic diet is more effective short-term.

Here’s the full Browning study if you care to read it yourself.

If I were obese and had NAFLD, I’d go on a very-low-carb ketogenic diet (like this one).

Steve Parker, M.D.

Reference:  Schugar, Rebecca, and Crawford, Peter.  Low-carbohydrate ketogenic diets, glucose homeostasis, and nonalcoholic fatty liver disease.  Curr Opin Clin Nutr Metab Care, 2012, vol. 15.  doi: 10.1097/MCO.0b013e3283547157

Low-carb Diet Killing Swedes

MPj04384870000[1]A recent Swedish study suggests that low-carbohydrate/high protein diets increase the risk of cardiovascular disease in women.  I’m not convinced, but will keep an eye on future developments.  This is a critical issue since many women eat low-carb/high protein for weight loss and management.

Researchers followed 43,000 women, 30–49 years of age at enrollment, over the course of 16 years.  In that span, they had 1,270 cardiovascular events: ischemic heart disease (heart attacks and blocked heart arteries), strokes, subarachnoid brain hemorrhages,  and peripheral arterial disease.  Food consumption was estimated from a questionnaire filled out by study participants at the time of enrollment (and never repeated).

In practical terms, … a 20 gram decrease in daily carbohydrate intake and a 5 gram increase in daily protein intake would correspond to a 5% increase in the overall risk of cardiovascular disease.

So What?

To their credit, the researchers note that a similar analysis of the Women’s Health Study in the U.S. found no such linkage between cardiovascular disease and low-carb/high protein eating.

The results are questionably reliable since diet was only assessed once during the entire 16-year span.

I’m certain the investigators had access to overall death rates.  Why didn’t they bother to report those?  Your guess is as good as mine.  Even if low-carb/high protein eating increases the rate of cardiovascular events, it’s entirely possible that overall deaths could be lower, the same, or higher than average.  That’s important information.

I don’t want to get too far into the weeds here, but must point out that the type of carbohydrate consumed is probably important.  For instance, easily digested carbs that raise blood sugar higher than other carbs are associated with increased heart disease in women.  “Bad carbs” in this respect would be simple sugars and refined grains.

In a 2004 study, higher carbohydrate consumption was linked to progression of blocked heart arteries in postmenopausal women.

It’s complicated.

Steve Parker, M.D.

PS: I figure Swedish diet doctor Andreas Eenfeldt would have some great comments on this study, but can’t find them at his blog.

Reference: Lagiou, Pagona, et al.  Low carbohydrate-high protein diet and incidence of cardiovascular diseases in Swedish women: prospective cohort study.  British Medical Journal, June 26, 2012.  doi: 10.1136/bmj.e4026

Dietitian Franziska Spritzler’s Six-Month Ketogenic Diet Trial Results

Steve Parker MD, Advanced Mediterranean Diet

Two diet books in one: 1) portion control, and 2) ketogenic

Ketogenic diets help many folks lose excess weight, return blood sugar levels toward normal, and move HDL cholesterol and triglycerides to a healthier range. I include a ketogenic diet as an option in my Advanced Mediterranean Diet (2nd Ed.). They are not for everybody.

Read about Franziska Spritzler’s experience with a ketogenic diet (not my version). Some quotes:

Well, after consistently consuming 30-45 grams of net carbs a day for six months, I have only positive things to say about my very-low-carb experience. Not only are my blood sugar readings exactly where they should be — less than 90 fasting and less than 130 an hour after eating — but I truly feel healthier,  less stressed, and more balanced than ever.

My diet consists of lots of fat from avocados, nuts and nut butters, olive oil, and cheese; moderate amounts of fish, chicken, beef, Greek yogurt, and eggs; and at least one serving of nonstarchy vegetables at every meal and a small serving of berries at breakfast.  It’s truly a rich, satisfying, and luxurious way to eat.