Sunday, November 28, 2010

Laughter is the best medicine

Did you know that laughter has MANY positive health benefits on your body?

Here's a few:

1. Your immune system. Yes, researchers have found that laughter is associated with an improved ability to fight illness. Specifically, it has been shown that laughter can boost your immune cells, as well as your antibodies (these guys help fight off infections).

2. Blood sugar levels. We don't want these levels to be too high in the blood (high levels are associated with diabetes). Early research has found a link to higher levels of laughter and resultant lower levels of blood sugar. Nice.

3. Blood pressure. In recent studies, Dr. Lee Burk, a psychoneuroimmunology researcher, found immediate decreases in blood pressure following laughter (and, not surprisingly, increases in blood pressure following stressful siutations).

4. Cholesterol levels. Likewise, Dr. Burk and colleagues, over the course of a 12-month experiment of diabetic patients, found increases in HDL ("good") cholesterol and decreases in LDL ("bad") cholesterol in the group of patients who were assigned to the "Laughter Group" of the experiment, with no such changes found in the "Control Group". The "Laughter Group", by the way, was subjected to 30 minutes per day of self-selected comedy television.

5. Inflammation. Among other things, inflammation in our bodies can lead to damage of the endothelium (a protective lining in blood vessels), fat and cholesterol build-up in coronary arteries and ultimately...heart attacks. Cardiologists at the University of Maryland Medical Centre have found a significant link between inflammation and laughter. Sure enough, groups who laughed less were associated with a higher incidence of heart disease.

5. Mood. Laughter helps elevate mood and lower the levels of certain "stress" hormones in the body (namely, cortisol, epinephrine, and dopamine). Chronically elevated, these hormones can have detrimental health effects on the body (including impairing your immune system functioning).

Are you getting the picture?

Now, I'm not saying that laughter is the cure to all of life's ailments. In fact, the researchers of these studies are quick to point out that larger scale studies are needed before drawing any type of conclusions from them. Fair enough.

But perhaps, in addition to making good lifestyle choices (like regular exercise, healthy eating, not smoking, getting enough sleep, for example), we could remember to not take ourselves too seriously. To take time to enjoy the simple things in life. And yes, to laugh a bit more.

With that in mind, have a good laugh watching this bit of hilarity from Ellen Degeneres and David Beckham:

http://www.youtube.com/watch?v=tsuvCozVaRI

You're welcome.

Sunday, November 21, 2010

The role of sit-ups in spinal stability

There’s a common notion in existence that suggests that sit-ups can help stabilize the spine and, therefore, help prevent back pain.

In fact, I’ve had dozens of patients proudly profess that sit-ups are in their daily exercise routine as part of their own self-made back care program.

So the question is – what is the role of sit-ups in helping to prevent back pain?

It’s a good question – an important question. Fortunately, it’s a question that has been well-studied, and answered beyond any reason of doubt. One of the leaders – if not THE leader - in spinal mechanics in the world is Dr. Stuart McGill, a professor of biomechanics at the University of Waterloo.

In Dr. McGill’s studies, it was found that regular straight-legged sit-ups put approximately 3500 Newtons of force (or about 730 lbs) of compression on the spine per sit-up. (By the way, we don’t want to have excess compression on our spines as it will lead to injury). To put those figures into perspective, the National Institute of Occupational Safety and Health has set a limit of compressive force on the spine for any action in the workplace to not exceed 3300 Newtons.

In other words, a single sit-up places more (damaging) compressive force on the spine than the legally maximal limit allowed in the workplace!

In an effort to counter this, some people have recommended substituting bent-leg sit-ups for straight-legged sit-ups, with the theory essentially being that the bent leg will take pressure off of the spine, and will, thus, reduce the compressive force on the spine. Guess what? This was studied too, and the compressive forces were found to be similar to that of the straight-legged sit-ups. Not good.

In spite of these findings, some might counter by suggesting that the pay-offs of working the abdominal muscles outweighs any risk of injury. This is completely wrong for multiple reasons. Firstly, you should note that Dr. McGill and colleagues have measured the muscle usage patterns of various abdominal muscle groups in response to many different abdominal exercises. It turns out that the sit-ups (both straight-legged and bent –knee) are not any better at working the core musculature than other measured exercises. In fact, for some important abdominal muscles, the sit-up exercises are less effective. So the “pay-offs” of these exercises are not even that good anyways.

If we couple the fact that the sit-ups are not especially effective at training the important core musculature with the proven truth that they put an exceedingly high compressive force on the spine, then you understand where I am going with this – sit-ups are bad news. Under no circumstance will I recommend them.

I was recently at a seminar in which Dr. McGill spoke. He reminded the delegates that it’s not so much that the compressive forces of sit-ups on the spine MAY cause an injury, rather, it’s that they, in fact, WILL cause injury. The only question is – when.

At some point, with enough repetitive compressive force is applied to the tissues of the spine, it will give out. Guaranteed.

In future postings I will discuss real “core stability”. I will describe what it is, as well as why it is important and necessary. Further, since I have already shot down the usage of sit-ups in any exercise program, I will discuss some GOOD core exercises – exercises that have passing grades in the scientific literature. These are exercises that will help prevent injuries, rehabilitate existing conditions, help you perform daily tasks comfortably and safely, and enhance sports performance.

Stay tuned.

In good health,


Dr. Michael Carney