Sports Medicine Bulletin
Dec. 27, 2011

Active Voice: Should I Drink My Orange Juice Before or After I Work Out?
By Russ Richardson, Ph.D.
Although a somewhat tongue-in-cheek title, these real-world questions are often raised following presentations of our group’s recent studies examining the interaction between exercise, oxidative stress and vascular function. Such a seemingly simple question is not so easily answered, especially for someone immersed in this particular area. This brief article should reveal that such a question cannot be answered without further questions. As the old saying goes, “the more you know, the more complicated things become.” More

Active Voice: High-Intensity Exercise for Overweight and Obese People
By Hassane Zouhal, Ph.D.
Physical activity is widely recommended for obese adults and children, based on extensive evidence of both health and functional benefits. Despite the widespread acceptance that undertaking physical activity is associated with a reduced risk of obesity and many other diseases, participation in regular physical activity remains low. As lack of time has regularly been shown to be a major barrier to physical activity and has been associated with low physical activity levels, recently the American College of Sports Medicine recommendations have placed greater emphasis on shorter-duration (i.e. a minimum of 20 minutes), higher-intensity exercise (HIE) done a minimum of three times per week. However, there is still much debate concerning the optimal intensity, duration and volume of exercise needed for the most favorable impact on health.More

Active Voice: Is It Possible to Simultaneously Improve Endurance and Strength?
By Laura Karavirta, Ph.D.
The most recent ACSM physical activity guidelines released in 2007 recommend three to five endurance training sessions and two strength training sessions each week. The rationale behind this recommendation is that both cardiorespiratory fitness and muscular strength are independently related to health and longevity. Given the training-mode-specific nature of adaptations and the rapid effects of detraining, the aim should be to simultaneously train for both endurance and strength. However, the complex interplay of several control mechanisms at the muscular and cellular level, which enable the human body to adapt to training, seem to be on a collision course when endurance and strength training are performed in tandem.More

Active Voice: Running Shoes & Foot Type — Is There a Good Match?
By Rudy Dressendorfer, P.T., Ph.D., FACSM
Running shoes are customized for foot arch posture and marketed with reference to poorly defined foot types. In running-specialty stores, a “shoe technician” will often visually assess foot type while the runner stands and walks in socks or barefooted. Also, the runner’s training shoes are usually inspected for signs of excessive wear on the medial or lateral side.

The foot type is categorized neutral if the medial longitudinal arch appears normal, overpronated if it is much lower than normal (shoes show more medial wear) or oversupinated if higher than normal (shoes show more lateral wear). A shoe type is then recommended to match the observed foot type: a neutral shoe for a normal foot, a motion-control shoe for an overpronated foot and a high-cushion stability shoe for an oversupinated foot.More

Active Voice: Train High or Low with Carbohydrate? Best Strategies for Improving Sports Performance
By Louise Burke, Ph.D., FACSM, FSMA
Traditionally, athletes have approached their daily workouts to train as hard as possible, using strategies that promote good performance, just as they would in a race or match. In many sports, these strategies involve fueling up with carbohydrates before, during and between workouts to sustain the capacity to produce power. Recently, however, scientists have proposed an alternative approach – training smarter by trying for greater outcomes from the same training impulse. The muscles’ reactions have shown that when a muscle is low in carbohydrate fuel, there is an increased chemical response to a training stimulus. One study by Bengt Saltin’s group in Denmark compared what happened when untrained people completed ten weeks of training with one leg training low (TL) and the other leg training high (TH). Although each leg completed the same training sessions, the TL leg beat out the TH leg in terms of the muscle’s changes and its capacity to exercise until fatigued. While some publicity surrounding this study suggests otherwise, the outcomes from TL weren’t achieved by following a low carbohydrate diet. Rather, this was accomplished by doing two sessions of exercise back-to-back so the muscle had no time to refuel before the second session. Only half of the training was done with low muscle fuel stores. More

Active Voice: Some Potential Benefits of Sprint Interval Exercise Training
By Peter Lemon, Ph.D., FACSM
The benefits of interval exercise training on aerobic performance and health have been known for many years. Recently, Gibala and colleagues have shown that sprint interval training (SIT; 4-6, maximal efforts of ~30 sec. duration separated by ~4 min. of recovery repeated several times a week for 4-6 wk) promotes similar cellular and endurance performance adaptations as more traditional endurance exercise training (ET) but with a fraction of the time commitment. In fact, it seems that as little as 15 minutes of SIT per week can produce aerobic effects similar to those achieved by 1.5-3 hours of ET per week. In a society that is increasingly time-sensitive, the potential benefits of SIT are at the very least intriguing. More

Active Voice: Understanding the Use of Antioxidant Supplementation with Exercise
By Allan Goldfarb, Ph.D., FACSM, FNAK
There is a great deal of conversation surrounding antioxidant supplementation and the potential need for these substances. There are numerous advertisements on the market for antioxidant vitamins and for packaged items touting that they contain antioxidants. The idea that antioxidants are necessary comes from the concept that they protect the body against harmful substances known as reactive oxygen species (ROS), or radicals. These radicals are typically molecules with an unpaired electron. Because they have a negative charge, they seek a balance and typically react with other molecules. This interaction often changes the affected molecules and could damage them. However, we now know that these ROS are important signaling molecules that help direct cellular action. More

Active Voice: Adding the ECG to Pre-Participation Exams for Competitive Athletes
By Victor Froelicher, M.D., FACC, FACSM
Unexpected deaths in those considered to be models of good health are sad and very visible because of the popularity of sports. Unfortunately, the public perception is that these deaths are much more common than they actually are. Controversy surrounds the best way to recognize and prevent these deaths, and the tendency has been to add more medical technology to the pre-participation exam (PPE). The following is an assessment of the situation regarding the addition of the electrocardiogram (ECG) to the PPE. More

Active Voice: Which Motivation Works Best for Long-Term Active Living and Weight Control?
By Pedro J. Teixeira, Ph.D.
About 20 years ago, Drs. Rod Dishman, James Sallis, Gaston Godin and many others were pioneering investigations in what distinguished active from sedentary people. By the mid-1990s, Dishman’s book Advances in Exercise Adherence accurately captured this landmark research. Following in their footsteps, questions such as “How should I frame my exercise prescription to target key mediators of change?” and “Which theory-based behavioral principles should I follow in my practice?” are crucial today for designing interventions that really help individuals change their behavior for good. Successful initiatives, such as Exercise is Medicine®, illustrate the timeliness of this topic. I personally feel that effectively helping more people become and remain physically active is the single greatest challenge in the field of exercise science today. More

Active Voice: Precooling Strategies Improve Cycling Performance in the Heat
By Megan Ross, B.S.
January is the month when cyclists travel “Down Under” to compete in the first event on the UCI Pro Tour calendar – an event held in the extreme heat of the Australian summer. With the stage‐race covering ~850 km over six days, in temperatures that often reach over 40°C/104°F, it is important that riders manage their heat stress. As such, research into practical means of cooling, either before, during or after exercise in hot temperatures continues to grow. More