At some level, getting in shape seems pretty straightforward: Eat a balanced diet, get enough sleep, and push yourself when you work out, whether it’s at the gym, in the pool, or on the track.  If you need some extra motivation, exercise classes and personal trainers are easy enough to find at your local gym, and the Internet is full of tools to help you keep track of what you eat and how much you burn.  All this seems pretty self-explanatory, so we might ask ourselves: do we really need new research from doctors and scientists to tell us about staying fit?

Exercise Physiologist: More than just a fancy word for personal trainer

Exercise physiologists are scientists and medical doctors who specialize in understanding how the human body responds to exercise.  Depending on the kind of work they do, their background may range from having a bachelor’s or master’s degree to a Ph.D. in exercise physiology or a related field (such as kinesiology, the study of human movement).  They primarily focus on two main groups of people: athletes who use their services to train competitively, and injured or sick people who may need their expertise for diagnosis or rehabilitation.

Elite athletes, in particular, value the input of exercise physiologists who are able to assess exactly how fit they are using a variety of quantitative measurements.  These measurements can be as simple as pulse rate (how fast your pulse returns to normal when you stop exercising is a sign of how fit you are) or as complicated as VO2 max (the amount of oxygen you use when you’re exercising as hard as you can), which can only be measured with the equipment in an exercise physiology lab.  Because endurance athletes have trained their bodies to use oxygen more efficiently, more oxygen circulates to their muscles and allows them to work faster and harder.  As a result, they generally have a higher VO2 max than the average person.  One way these athletes can therefore monitor their fitness is by periodically checking their VO2 max to see if it improves with training or declines with de-training.

Exercise physiologists also work in the clinic to diagnose diseases, such as mitochondrial disorders, which can be characterized by exercise intolerance []. Mitochondria can be called the “powerhouses of the cell”, so mitochondrial disorders can result in changes in physiology and energy availability for those people suffering from them.  No, this does not mean you have a mitochondrial disease if the inner voice telling you to kick back on the couch to watch TV usually drowns out the one suggesting you go for a jog.  Exercise intolerance is measured with specially designed exercise tests, and is just one of the ways an exercise physiologist can help to diagnose a mitochondrial disease.  Exercise physiologists can also assist with the rehabilitation of patients with heart problems, by designing an appropriate training plan and monitoring the patient over time.

Do we really need to still be studying this stuff?

Humans have been exercising since ancient times, when running speed might have meant the difference between catching dinner and being dinner.  Even in this modern era of gym memberships and Pilates classes, scientists continue to make new discoveries that change the way we think about exercise.  Part of this has to do with the way exercise studies were previously done.  Exercise physiology was not formally established as a field until the 19th century, and many of the fitness measurements used by exercise physiologists remained the same for much of the 20th century.  Recent advances in technology have allowed scientists to conduct more sophisticated studies that have lead to more precisely targeted techniques and treatments.  In addition, most studies done in the 20th century focused on men.  More recent research has shown, perhaps unsurprisingly, that women react differently than men to similar diet and exercise regimens []. This means that much of the currently available scientific advice might only apply to men, and that repeating older studies with female subjects will undoubtedly enhance our understanding of the differences between how women and men respond to exercise.

What does all this science mean for me?

Although peer-reviewed articles about exercise science are published all the time, many are available only to scientific institutions with journal subscriptions or to non-subscribers willing to pay an often-hefty fee.  So how can you keep up with recent advances that are actually relevant to you?  Fortunately, the most exciting results are often reported in the news and on a variety of blogs, and these articles tend to include suggestions for how you might incorporate the new findings into your own life.

For example, scientists recently discovered that endurance athletes can improve performance not only by drinking beverages with carbohydrates, but also by simply swishing a drink around before spitting it out []. This only works with real carbohydrates (not artificial sugars), when the athletes are hungry, and when they take the sugar orally.  Even directly injecting it into the blood didn’t have the same effect.  This suggests that carbohydrates hit receptors in the mouth that tell the brain that fuel is coming, so it’s OK to work out harder, whether or not you actually swallow the carbohydrates.  If sports drinks give you stomachaches or you just want to avoid the calories, rinsing your mouth with a sports drink could give your workouts an added boost!

On the psychological front, scientists have also found that superstitions have a significant impact on physical and mental performance.  German students putted more accurately if using a ball they were told was “lucky,” finished agility tests more quickly if someone wished them luck, and tried harder on memory and vocabulary tests when they had a lucky charm with them [].This is a variation of the “placebo effect,” in which our unconscious mind actually causes a biological effect to occur simply because we expect it to – regardless of whether or not there is any real reason for it!

It may seem like new articles are published every week that give contradictory advice on the best way to get in shape and stay healthy.  First we’re told to eat carbohydrates, then not to eat carbohydrates, etc.  But that’s how science works!  Technology is constantly advancing, giving scientists access to more accurate information about the way we react to exercise.  Sometimes a technique that works well for some people turns out to be actively detrimental to others.  The only way to figure this out is by collecting more and more data.  As scientists figure out why, for example, eating protein helps some people recover from exercise more than others [], they want to get that information out as soon as possible to help you make better exercise decisions for yourself.  This often means publishing studies that may eventually contradict each other.  It’s a tough balance between getting out useful information quickly, and carefully exploring all the complex ways the human body can react to a particular regimen.  All the more reason to stay up to date with the latest news!

Laura Strittmatter

Harvard Chemical Biology

References

[] Mitochondrial Disease (MedicineNet)

[] Phys Ed: What Exercise Science Doesn’t Know About Women (Gretchen Reynolds, New York Times)  http://well.blogs.nytimes.com/2010/06/30/phys-ed-what-exercise-science-doesnt-know-about-women/

[] A Carb Boost Without the Carbs (Tara Parker-Pope, New York Times) http://well.blogs.nytimes.com/2010/07/19/a-carb-boost-without-the-carbs/

[] Phys Ed: Does Lucky Underwear Improve Athletic Performance? (Gretchen Reynolds, New York Times) http://well.blogs.nytimes.com/2010/07/28/phys-ed-does-lucky-underwear-improve-athletic-performance/

Interesting Links

New York Times Well Blog

http://well.blogs.nytimes.com/

The American College of Sports Medicine

http://www.acsm.org/

The American Society of Exercise Physiologists

http://www.asep.org/

Track your diet and exercise online

http://fitday.com/

What if I want to be an exercise physiologist?

http://www.explorehealthcareers.org/en/Career.142.aspx

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