Sports Medicine Bulletin
Dec. 28, 2010

A Holiday Greeting from ACSM

Happy Holidays! View a special holiday message from ACSM.

Can Kettlebells Do It All?
By John P. Porcari, Ph.D., FACSM
To me, the mention of kettlebell training evokes the vision a singlet-clad, mustachioed weightlifter in a dark gymnasium extending a weight overhead. That vision may not be that far-fetched, as kettlebells are thought to have originated in Russia during the early 1700s. In recent years, they have grown in popularity as part of individual and group fitness classes.

First of all, what is a kettlebell? A kettlebell looks like a cannonball with a hooped handle on the top. They are typically made of cast iron and historically looked rather rudimentary. Nowadays, as their popularity has grown, they come in a variety of colors and often have a plastic coating. Kettlebells range in weight from 5-175 pounds, with the original version weighing 1 Pood (approximately 16 kg or 35 lbs). More

Revisiting the Myth About Exercise
By Barry Braun, Ph.D., FACSM
In late 2009, a cover story in TIME magazine surprised many of us with the provocative title "The Myth of Exercise." The central theme of this article was not only that exercise is ineffective as a weight loss tool, but that bouts of intense, structured exercise (e.g. what most people do at "a gym") are actually counterproductive because they increase appetite and lead to excess food intake that can cause weight gain. For those who read the article carefully, the utility of exercise as medicine to reduce risk for chronic diseases, strengthen bones, enhance mood and improve cognitive function was unchallenged. Rather, the author took great pains to argue that it would not "make you thin."

The idea that exercise alone, with no conscious change in diet, induces only modest weight loss is not new. Anecdotally, all of us have been cornered by people claiming to have spent hours each week walking, running, stair-stepping, etc., and are displeased with the results on the scale or in the mirror. At least in my experience, more of these stories are related by women than by men. Well-designed studies bear out the anecdotes. When individuals are placed in a supervised exercise program with no diet intervention, weight loss tends to be modest, particularly for women. These results are usually explained as “compensation,” either less physical activity outside the structured exercise program, increased energy intake, or both. Smaller, more controlled studies lend support to the idea that caloric intake rises in response to higher energy output. Upon initiating an exercise training program there are changes in appetite and some key energy-regulating hormones that are consistent with a rise in calorie intake; particularly in women. More

Milk, Athletes & Nutritional Recovery Routines — Benefits Beyond Nature's Intent?
By Nancy R. Rodriguez, Ph.D., R.D., FACSM
As I sat at a research roundtable in the fall of 2001, shortly after completing one of my first investigations evaluating the potential benefits of milk to protein utilization by endurance athletes, a colleague commented, “It is not likely that milk will ever be a sports beverage.” At the time, the critical recovery beverage following an endurance exercise bout was carbohydrate-based with some electrolytes tossed in for good measure. More important, the palatability of milk as a thirst-quenching drink seemed unlikely.

Fast forward to 2010. Chocolate milk, the most popular flavored milk, has found a niche in the recovery routines of many different athletes and teams. Indeed, milk – chocolate milk in particular – can be found alongside other sports beverages in coolers in training facilities and at training tables across the country, if not the world. Most recently, “supercharged” versions of milk have entered the marketplace by distilling recent scientific findings into advertising campaigns that tout the benefits of adding more milk protein to the natural product. More

The Downside of Energy Drinks — Negative Performance and Psychological Effects
By Conrad Woolsey, Ph.D., CHES
Of the more than 500 brands of energy drinks (EDs) now available, several contain 3-4 times the amount of caffeine (300+ mg/8 oz.) as standard energy drinks (80 mg/8 oz.) such as Red Bull. New popular drinks such as Spike and Redline also contain other herbal stimulants such as evodamine and yohimbine which are more powerful and dangerous than caffeine. Strategic marketing campaigns proclaiming improved performance, concentration, and mood have influenced increased ED use. ED use significantly predicts increased alcohol use, the illicit use of amphetamines (Adderall), and risk-taking such drinking and driving. Additionally, in a randomly assigned double-blind placebo controlled study where we tested EDs on a dynamic performance skill, we found performance improvements only when examining one-dimensional variables (e.g., reaction time), which do not necessarily translate well into coordinated multi-dimensional skills. Performers perceived they were doing better, but actually made significantly more errors, due to being hyper-focused and/or over-aroused. Technical skills rely on timing and coordination, and EDs can and often do reduce performance. As a sport psychology consultant, I regularly work with elite athletes whose performances have suffered from using EDs, particularly in high-pressure situations.

There are several contributing factors, such as athletes’ reduced ability to self-regulate biofeedback and state-dependent negative effects on the cerebellum (responsible for coordination/sequencing of motor movements). Typically, my clients are able to effectively utilize relaxation and/or excitation techniques to improve biofeedback and hormonal responses as well as a performance mindset to improve confidence, concentration, and mood. However, due to the pharmacodynamics of EDs, as well as the adverse neurological and psychological adaptations, in the long run, athletes who regularly use EDs are likely to experience performance decrements and to suffer from neurochemical imbalances. More

Get Stronger to Stay Independent Longer
By Teresa Merrick, Ph.D.
When Dr. Walter Bortz II, eminent geriatric expert and author of “Dare to Be 100”, first appeared at ACSM’s Health and Fitness Summit in 2002, he said something that galvanized my thinking: The biggest predictor of whether you’ll end up in a nursing home is not the strength of your heart; it’s the strength of your legs.

The reason should be obvious to exercise professionals: your legs can make your heart stronger, but your heart can never make your legs stronger.

Strength training is truly the “fountain of youth” for adults over 40. Stronger muscles from strength exercise make movement of all kinds more inviting by raising the bar of capability. Instead of daily activities such as carrying groceries, walking from parking lots and up stairs, or getting out of chairs and cars being near-maximal efforts, they become less fatiguing and more do-able. More

Estrogen, Like Androgen, Can Affect Muscle Strength
By Dawn Lowe, Ph.D., FACSM
Estrogens and androgens are the primary sex hormones of females and males, respectively, and these hormones are quite different. Right? We recognize androgens as anabolic steroids that influence the response of skeletal muscle to exercise in males. But what about estrogen’s influence on exercise and skeletal muscle in women? If you are not so sure about this answer, you are not alone.

The literature on women is mixed, with some studies finding benefits of estrogens on skeletal muscle and exercise responses while many others not. Animal models are often used in research to address questions related to exercise and muscle adaptations, but thus far they have not added clarity to these estrogen questions. A main reason for this is that the preponderance of rodent studies are conducted on male rats and mice. This is particularly true when the scientific question revolves around aging. I remember as a post-doctoral associate causally asking senior investigators, “Why do you use male mice/rats?”, and inevitably the answer would be something like, “So that we don’t have to deal with fluctuating/changing hormones that would add variability to …” This seems reasonable given that a big advantage of using rodents in the first place is to reduce biological and environmental heterogeneity that is inherent to studies on humans. Then again, fluctuations and age-related changes in the sex hormones are biological reality. More

Exercise Test to Screen for Obstructive Sleep Apnea?
By Trent A. Hargens, Ph.D.
Sleep disorders, of which obstructive sleep apnea (OSA) is the most common, pose a significant personal and public health risk. Not only does OSA increase risks of hypertension, diabetes, congestive heart failure and cardiovascular disease, but it also accounts for a five-fold increase in the risk of motor vehicle accidents. As a result, OSA is a health problem that should concern all of us.

Recent estimates suggest that as many as one in four American adults are at risk for and should be evaluated for OSA. As age and obesity are prime risk factors for this disorder, we should expect the prevalence to increase as our population ages and becomes more obese. Unfortunately, the majority of at-risk individuals goes undiagnosed for OSA, probably due to the high cost of testing and treatment, inconvenience, and long wait time for full-night polysomnography (PSG) testing, which remains the gold standard test for diagnosis. Simpler and more cost-effective screening tools are clearly needed to improve the risk stratification and clinical decision-making that lead to patient selection for diagnostic PSG testing. If we can optimize screening and selection for PSG testing, we can conserve costs and allow the patients to be tested who most need assessment. More

Flawed Method May Underestimate Childhood Obesity
By Daniel P. O'Connor, Ph.D.
Many of us have seen headlines and media reports about the obesity epidemic plaguing U.S. children, with prevalence exceeding 35 percent by some estimates. While these numbers are alarming, many of these reports use national surveys or databases containing parent-reported values for their child’s height and weight, and these values are often used to compute body mass index (BMI) and identify obesity rates. The inaccuracy of proxy reporting is well known, but we were surprised to find few reports investigating the accuracy of parent-reported height and weight across the entire span of childhood.

Using archival data from an orthopedic clinic, we compared measures of parent-reported height and weight for 1,430 children (55 percent boys) who were between 2 and 17 years old. None of these children were seeking treatment for weight-related issues. Using objectively measured values, we determined that 17 percent of the children were overweight and 19 percent were obese. More

Walking at the Desk — Workplace Innovation Fosters Better Health Resolution
By Dinesh John, Ph.D.
Up until the last century, a high level of physical activity was an integral part of life for most humans. Due to advances in modern technology, ‘essential’ physical activity has been dramatically reduced in the workplace, resulting in an overall decrease in energy expenditure during the workday. A large segment of the labor force is now engaged in sedentary occupations that involve long hours of continuous sitting – in fact, U.S. Census Bureau statistics suggest that up to 75% of American workers are sitting in front of a computer at work!

In the early 1700s, the work of an Italian physician named Bernardo Ramazzini led to the field of occupational medicine. He studied the health of workers in over a hundred different kinds of jobs and concluded that ”those who sit at their work and are therefore called 'chair workers,' such as cobblers and tailors, suffer from their own particular diseases ... [T]hese workers ... suffer from general ill-health and an excessive accumulation of unwholesome humors caused by their sedentary life.” Confirming Ramazzini’s observations, current research has shown that prolonged sitting is associated with obesity, cardiovascular disorders, and an impaired metabolic profile. Thus, reducing sitting in the workplace may potentially improve the health status of sedentary office workers. More

Where is Exercise Physiology in Medical Education?
With Lee Pierson, M.D.
Q: How do you see your knowledge and special training in exercise physiology relating to your medical career and care for patients?

I am interested in a career in cardiology, with emphasis on secondary prevention of cardiac events and disease progression in patients with coronary disease. I believe that exercise, as part of comprehensive cardiac rehabilitation, is very important to help reduce disease progression and prevent cardiovascular events.

I am interested in research to define the type, intensity and duration of exercise that is optimal to achieve health outcomes such as blood pressure reduction, weight loss, changes in lipid profile, and glycemic control. Research in these areas will add to the current knowledge base to help further refine the exercise prescription for patients with specific risk factors for the disease progression. My goal is to have a positive influence on the use of exercise as an adjunct to optimal medical therapy in treating patients with coronary disease or risk factors for its development.