Fitness & Exercise

Bad Types of Exercise to Avoid

Unfortunately most of us interested in exercise took an American approach to exercise when Dr. Cooper first popularized exercise in the late 1960s. We took the "more is better" approach and started racking up the miles or hours in the gym or aerobics classes and competing in marathons or triathlons. Turns out that this excessive cardio was likely not much better at improving longevity than being sedentary. Most exercise programs today are built based upon a very incomplete picture of the physiology of your body. Getting cardiovascular benefits requires working all your muscle fibers and their associated energy systems. Unfortunately for the long slow cardio folks out there, this cannot be achieved with traditional slow cardio. Unfortunately, anywhere from 90 to 98 percent of people who exercise are NOT doing high intensity exercises. By focusing on slow endurance-type exercises, such as running on a treadmill, you actually forgo many of the most profound benefits of exercise. Your heart has two different metabolic processes: * The Aerobic, which require oxygen for fuel, and * The Anaerobic, which do not require oxygen.

Let's simplify this. Studies show that we have three different types of muscle fibers; slow twitch (type I), and fast twitch (fast twitch IIa & IIb). If you don't actively engage and strengthen all three muscle fiber types and energy systems, then you're not going to work both processes of your heart muscle. Many mistakenly believe that cardio works out your heart muscle, but what you're really working is your slow twitch muscle fibers. You're not effectively engaging the anaerobic process of your heart.


I want to paint the picture of what high intensity is, what the benefits are, and why ANYONE can partake in this type of exercise. High intensity exercises sequentially recruit all the different types of muscle fibers in your body, starting with the smaller motor units made up of slow-twitch fibers which are primarily aerobic (have a lot of endurance and recover quickly) -- to the intermediate fibers -- followed by the fast twitch fibers. If you stopped and gave it some thought, it's actually easy to see that your body was designed for high intensity, short interval exercise. In nature you will never see an animal jogging -- hint hint. Instead of being sedentary for much of the day and then running for an hour on a treadmill, our ancient ancestors combined lots of walking with regular lifting and short bursts of high-intensity activities. It is safe to say that science backs up the notion that they did not have near the amount of cardiovascular diseases and metabolic issues that we face today. So why did we fix what wasn't broken? Steady state aka long slow exercise trains the plasticity out of your physiologic system. This is the ability to handle widely varying levels of exertion within a short span of time. Yes, you can make yourself less adaptable to physical stress in general.

Your fast twitch fibers are largely glycolytic and store a lot of glucose (carbs). When these muscles are recruited, it creates the stimulus needed to grow muscle. We have to remember that muscle is very metabolically expensive. If you become sedentary and send your body the signal that this tissue is not being used, then that tissue is metabolically expensive. The adaptation the body takes is to deconstruct that tissue (Use It Or Lose It). At the same time, it enlarges the glucose storage reservoir in the muscle, which in turn enhances your insulin sensitivity. Normalizing your insulin is one of the primary health benefits of exercise, and this is particularly true in the case of high intensity exercise. Slow long distance cardio recruits the slow twitch fibers only. If you remember, earlier I said those fibers recover quickly. So rather than moving to the next set of motor units, you're just recruiting that one group over and over again. As a result, your intermediate and fast twitch fibers actually begin to atrophy aka SHRINK AND DIE! Aside from losing muscle mass, you'll also experience earlier onset of loss of insulin sensitivity, leaving yourself open to a full scale of health ramifications, such as metabolic syndrome (Diabetes).

High intensity short interval training can be as simple as getting on a recumbent bike and pedaling as hard as you can for 30 seconds, then resting for 30 seconds and repeating that process for 10 minutes. But it also relates to the individual who can perform a set of squats for 6+ repetitions, move on to a set of step ups for 6+ repetitions on each leg and starting over until 2+ rounds are completed. There is no one size fits all. Everyone has to start from somewhere.

Why long distance running isn't that great

I think we can all agree that when it comes to exercise, more is not always better. Granted, this warning does not apply to the vast majority of people reading this, as most people are not exercising nearly enough. But it's still important to understand that not only is it possible to over - exercise, but focusing on the wrong type of exercise to the exclusion of other important areas can actually do you more harm than good. A study performed in 2011 by the European Heart Journal looked at the heart function of 40 elite long term endurance athletes after four endurance races of varying lengths. By measuring cardiac enzymes and taking ultrasounds, the researchers were able to measure the acute effects of extreme exercise on the heart. They found that: ~ Right Ventricular function diminished after races. ~ Blood levels of cardiac enzymes (markers of heart injury) increased. ~ The longer the race, the greater the decrease in RV function. ~ 12% of the athletes had scar tissue in their heart muscle detected on MRI scans one week after the race. The authors of the study concluded that intense exercise causes dysfunction of the Right Ventricular, but not the Left Ventricular. Although short term recovery appears complete, chronic changes may remain in many of the most practiced athletes.

This study is a little scary huh? Right Ventricular damage is not good. Diseases that effect this portion of the heart tends to cause electrical instability that may increase the risk of sudden death. Although exercise reduces your cardiovascular risk by a factor of three, too much vigorous exercise, such as marathon running, actually increases your cardiac risk by seven, according to a study presented at the Canadian Cardiovascular Congress 2010 in Montreal. This is a powerful lesson to anyone who engages in large amounts of cardio exercise, because as it turns out, excessive cardio may actually be counterproductive.

Exercise remains the most effective and safest means to prevent and treat heart disease. The overwhelming majority still exercise far too little. I believe the US suffers from sever exercise deficiency. This is only a note of awareness into one of the more popular means of exercise, "long distance running."

The real answer is to exercise correctly and appropriately, and making certain you have adequate and proper recovery. This can be just as important as exercise itself. Part of a healthy regimen is variety. I could go through a load of overwhelming evidence indicating that conventional cardio or long distance running is one of the worst forms of exercise there is. Here are a couple that confirm the health alarming effects of long distance running: ~ A 2006 study screened 60 non-elite participants of the 2004 and 2005 Boston Marathons, using echocardiography and serum bio-markers. Just like the featured study above, it too found decreased right ventricular systolic function in the runners, caused by an increase in inflammation and a decrease in blood flow. ~ In a study published in the Journal of Applied Physiology., researchers recruited a group of extremely fit older men. All of them were members of the 100 Marathon club, meaning athletes who had completed a minimum of 100 marathons. Half of these lifelong athletes showed some heart muscle scarring as a result - specifically the men who had trained the longest and hardest. ~ Recently published in the journal Circulation, this animal study was designed to mimic the strenuous daily exercise load of serious marathoners over the course of 10 years. All the rats had normal, healthy hearts at the outset of the study, but by the end most of them had developed "diffuse scarring and some structural changes, similar to the changes seen in the human endurance athletes."

Research emerging over the past several years has given us a deeper understanding of what your body requires in terms of exercise, and many of our past notions have simply been incorrect. In the next post I will dive into what the research says about exercise based on our human physiology.

References. Seigel, A. (2001). Effect of marathon running on inflammatory and hemostatic markers. American Journal of Cardiology, 88(8), 918-920. Retrieved from Burns, A. (2011). Exercise-induced right ventricular dysfunction and structural remodelling in endurance athletes. European Heart Journal.