American Society of Exercise Physiologists
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Issue: #12 December 2009
Thank you for being part of our community. ASEP is the specific voice for (historically under-represented) Exercise Physiologists. Please use this Newsletter as a link to ASEP resources from scientific journals to professional papers, to employment and related opportunities. And be sure to click on "More On Us" at the left for the ASEP-newsletter's parent web site.
 
Happy Holidays! 
-Lonnie Lowery and Jonathan Mike, ASEP-Newsletter Editors 
 Editor's Corner

editorialExercise Physiology in High School


This term I am teaching an Exercise Physiology class to 21 high school students. The students choose this class because it is part of the Bio-Health Science pathway offered at our school. The prerequisite for the class was either Anatomy & Physiology or Athletic Training 1 so I knew the students would have a general knowledge of the human body. The class is not required but many students felt it would help when they attend college. Eighty percent of the class has played or is playing a sport in high school so I use the students as examples. The majority of the class is looking at the medical field (athletic training, nursing or physical therapy) when they attend college. The text book I am using is "Physiology of Sport and Exercise" Guide-4th Edition by Jack Wilmore, David Costill, W. Larry Kenney.
 
From the response of the class thus far, I think this is an area that is being overlooked by our high schools and needs to be further explored. I set the class up so we would cover 7 chapters emphasizing the major concepts of each chapter, however we do not go into the depth the text book allows us. My rational for this was to introduce the concepts (i.e. three types of muscle, actin / myosin and the sliding filament theory, program design / needs analysis, adaptations to exercise, training for sports, nutrition and adolescents in sports) and then apply the material to their sports. I feel that if the students learn the basics they will have a better understanding when they take the college class.
 
The true learning in this class has occurred outside the classroom. Students in class are able to apply the basic concepts we have covered in class to real life experiences. On several occasions I have had a chance to interact with the students in the weight room so we can talk about the topics we are learning in class. One of my favorite happened after school in the weight room when a couple of the athletes wanted to do 100's. That is 100 reps of an exercise. They feel the burn and think that translates into hypertrophy. I asked one of my exercise physiology why that was not a good idea. He as able to explain that performing 20-30 reps at one time before they have to stop was actually working type I fibers which are used in endurance events. If the athletes wanted to get stronger they needed to be working type II fibers which meant less reps and more weight. As he and I talked, I would ask questions and he would tell his teammates the answers. At first they chuckled until I explained that the student was correct and if they listened to him they would improve their strength. This type of interaction has occurred with other students as well. The students are even talking to their coaches about training which shows me that they understand the material.
 
Most high school offer an Anatomy and Physiology or Athletic Training class to their students. By expanding the class selection to include a basic Exercise Physiology or Kinesiology class students would not only have more choices but they would be exposed to a wider variety of sciences.
 
How many times have you heard that American students are over weight and behind in the sciences? Maybe if we start to teach students the science of why they need to exercise and how it affects the body (EXERCISE PHYSIOLOGY) the trend will start to change.
 
I know Forensics has made a push to get into the high schools and more schools have started offering it. As the leaders in Exercise Physiology I feel that if you would show teachers the benefits of the class and how exciting can be, more high schools would choose to include it in their curriculum.  
 
Patrick McHenry MA, CSCS*D
Ask the EP 
  
Q:  What encompasses Resting Metabolic Rate and what factor influence this measurement?
 
Resting Metabolic Rate (RMR) is a measure of basic biologic energy needs and is commonly used to predict daily energy requirements of individuals and populations in both research and clinical settings (1). The RMR in a normal active healthy person accounts for 60-75% of total energy expenditure (TEE), and potential more in a very sedentary person. An intervention that greatly alters RMR may have a profound effect of energy balance. An increase in RMR to different exercise modes possibly assists in overcoming the low energy expenditure accustomed with obesity (2).  In order to quantify the amount of difference in RMR observed with exercise involvement, it is important to identify natural variation that occurs with an individual from day to day without training.
 
Knowledge of resting metabolic rate (RMR) is important in clinical applications for defining appropriate nutritional support and determining caloric needs for energy balance and weight management (3).  In order for RMR to be useful, individuals need to be confident in the accuracy of the measurement and knowledge of the variability of repeated measures. There are a wide range of indirect calorimetry systems including whole room calorimeters, doubled labeled water, open circuit Douglas bags, metabolic carts, ventilated hood systems, and hand-held devices- have been published (1,4,5,6). Many factors- including anxiety, diurnal variation, thermic effect of food, elevated EPOC, stimulants, and pharmaceuticals, can affect measures of metabolic rate ( 7).  Due to these factors, methodological variability, and individual variation, it is important to attempt to define conditions under which a measurement can be considered an RMR. Therefore, standard conditions have been developed. These are generally defined as an 8-12 fast and a 12 hour abstinence of exercise (1,7).
 
There has been research conducted to determine individual day to day variability in RMR. One study in 19 healthy participants established that after 3 measurements completed over 6 weeks, average variation was 3.3% +/- 2.1% (8).  Similarly, in a study with older people, 6 men and 13 women were measured on 3 separate occasions, with average variations of 4% for men and 3% for women, suggesting older people have a lower variation to that of younger people (9).  However, there seems to be a range of variation of RMR ranging from 2-10%, sited from Haugen (7),and 5-14% sited from Roffey (1).
 
When testing RMR, it is recommended to use the standard condition of an 8-12 hour fast and a 12 hour abstinence from exercise. However, in the interest of time, some conditions may have to be modified. When performing repeated measures of RMR, one would expect an afternoon RMR to be within 27-171 kcal/day of morning RMR 95% of the time. Explanations for differences in RMR depend upon which indirect calorimetry system is used, which can vary as well. Some believe using a mouthpiece and nose clip may result in an increased RMR and has been shown to bring about changes in tidal volume and ventilation in healthy subjects breathing room air (10). For individuals not accustomed to a mouthpiece and nose clip, this could affect resting physiologic function, as anxiety and apprehension may influence arousal levels, leading to increase in ventilation, and ultimately RMR measurement error.
 
Another factor affecting RMR is pre- and postprandial meal response; specifically, the diet-induced thermogenesis response to a mix meal. In an earlier study conducted by Westrate (11), measurement of diet -induced thermogenesis was taken for 4 hours after a meal. The patterns of the postprandial response indicated that in men and women with an energy content of > 1500kj can be nearly completely assessed within 3 hours. A 4-5 hour fast may be adequate time to decrease the effect of the thermic effect of food on RMR measurement. Therfore, size and meal composition greatly affects the accuracy of RMR. Future research should consider the precautions and contraindications before assessing RMR. Following a standard protocol to minimize potential error whenever measuring RMR is highly recommended.
 
 
Jonathan Mike,  MS, CSCS, USAW, NSCA-CPT,
Doctoral Student, Assistant Editor

References
 
1).   Roffey DM, Byrne NM, Hills AP. Day-to-day variance in measurement of resting metabolic rate using ventilated-hood and mouthpiece & nose-clip indirect calorimetry systems. JPEN J Parenter Enteral Nutr. 2006 Sep-Oct;30(5):426-32.
 
2). Speakman JR, Selman C. Physical activity and resting metabolic rate. Proc Nutr Soc. 2003 Aug;62(3):621-34. Review.
 
3). McArdle, W, Katch F, Katch V. Exercise Physiology: Energy, Nutrition and Human Performance. 5th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2001
 
4). Nieman DC, Trone GA, Austin MD. A new handheld device for measuring resting metabolic rate and oxygen consumption. J Am Diet Assoc. 2003 May;103(5):588-92
 
5). Conway JM, Irwin ML, Ainsworth BE. Estimating energy expenditure from the Minnesota Leisure Time Physical Activity and Tecumseh Occupational Activity questionnaires - a doubly labeled water validation. J Clin Epidemiol. 2002 Apr;55(4):392-9
 
6). King GA, McLaughlin JE, Howley ET, Bassett DR Jr, Ainsworth BE. Validation of Aerosport KB1-C portable metabolic system. Int J Sports Med. 1999 Jul;20(5):304-8
 
7).  Haugen HA, Melanson EL, Tran ZV, Kearney JT, Hill JO. Variability of measured resting metabolic rate. Am J Clin Nutr. 2003 Dec;78(6):1141-5.
 
8). Adriaens MP, Schoffelen PF, Westerterp KR. Intra-individual variation of basal metabolic rate and the influence of daily habitual physical activity before testing. Br J Nutr. 2003 Aug;90(2):419-23.
 
9). Gibbons MR, Henry CJ, Ulijaszek SJ, Lightowler HJ. Intra-individual variation in RMR in older people. Br J Nutr. 2004 Mar;91(3):485-9.
 
10). Scott CB. Resting metabolic rate variability as influenced by mouthpiece and noseclip practice procedures. J Burn Care Rehabil. 1993 Sep-Oct;14(5):573-7
 
11). Weststrate JA. Resting metabolic rate and diet-induced thermogenesis: a methodological reappraisal. Am J Clin Nutr. 1993 Nov;58(5):592-601.
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Opportunities Related to Exercise Physiology
 
The Department of Kinesiology at the University of New Hampshire... is currently seeking applicants for a tenure track appointment in Exercise Science at the Assistant or Associate Professor level. ...more information...
 
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NOTE: ASEP Board of Directors with approval of The Center for Exercise Physiology-online developed the "EPC Petition Guidelines" for doctorate exercise physiologists to become Board Certified.
 

Thank you for perusing our opinions, facts and opportunities in this edition of the ASEP-Newsletter.
 
Sincerely,

Lonnie Lowery
American Society of Exercise Physiologists

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