Primer for the Exercise and Nutrition Sciences (eBook)

Preface 1. Introduction: Thermodynamics, Bioenergetics, Energy Expenditure Part 1. Thermodynamics 2. Within and Without: Systems and Surroundings 2.1. Isolated systems 2.2. Closed systems 2.3. Open systems 2.4. Life is an open system 3. Conservation 4. Matter and Energy 4.1. Matter 4.2. Energy 4.3. Internal energy 4.4. Internal energy exchanges 5. Energy Accountability: Enthalpy (H) 5.1. The chemical reaction system 5.2. Chemical (standard) enthalpy exchanges 5.3. Biochemical (non-standard) enthalpy exchange 6. Energy has bias: Entropy (S) 6.1. 2nd laws of thermodynamics 6.2. Energy distribution 7. The energy exchange gradient: Gibbs energy (G) 7.1. Delta Go 7.2. Energy unification 7.3. Delta Go’: Closed systems under standard conditions 7.4. Delta G: Non-standard conditions Part 2. Bioenergetics 8. Life’s Currency: ATP 8.1. ATP: structure and content 8.2. ATP: energy exchange 8.3. ATP: turnover efficiency 8.4. ATP utilization (demand) 8.5. ATP re-synthesis 9. Metabolism as an Energy Exchange Device 9.1. Metabolic power: force and flow 9.2. Negative entropy (?) 9.3. Dynamics of a metabolic pathway 9.4. Intracellular transport 9.5. Time 9.6. Exergy synopsis 10. Anaerobic Metabolism 10.1. A brief history of anaerobic biochemistry 10.2. The glycolytic gradient 10.3. Glycolytic heat and entropy 10.4. 'High-energy' phosphate buffering 10.5. Anaerobic speed 11. Aerobic Metabolism 11.1. Mitochondria 11.2. Krebs cycle: gradient 1 11.3. Electron transport chain: gradient 2 11.4. Proton-motive force: gradient 3 11.5. The creatine phosphate shuttle 11.6. ATP tally Part 3. Energy Expenditure 12. Aerobic Energy Expenditure 12.1. Combustion, respiration and heat 12.2. Thornton’s law: combustion 12.3. Respiration and energy expenditure 12.4. Heat and gas exchange 12.5. Aerobic energy expenditure as heat and entropy 12.6. CO2 and O2: aerobic and anaerobic energy exchange 13. Anaerobic Energy Expenditure 13.1. The oxygen deficit 13.2. Lactate 14. Energy Expenditure at Rest 14.1. Measuring energy expenditure: calorimetry 14.2. The energy expenditure of rest 14.3. Eating and energy expenditure 14.4. Pregnancy and energy expenditure 15. Energy Expenditure of Activity (Work and Exercise) 15.1. Rate vs capacity vs METs 15.2. Muscle 15.3. Work and energy expenditure relationships 15.4. Glycolytic versus respiratory efficiency 16. Total Energy Expenditure for Exercise and Recovery 16.1. Aerobic exercise energy expenditure 16.2. Anaerobic exercise energy expenditure 16.3. Aerobic recovery energy expenditure 16.4. Dismissing the oxygen debt hypothesis 16.5. Total energy expenditure 16.6. Weight loss: low vs high intensity activity

Preface (S. V-VI)

What a journey writing this text has been. The lengthy voyage started well before the idea hatched of authoring a text that contained the word “thermodynamics”! I was informed by my good friend and sometimes colleague Dr. Jose Antonio that by including that word in the title, nutritionists and exercise physiologists might avoid the subject. But almost every step of my expedition was taken on a rather solid foundation of thermodynamics and as such the topic could not possibly be omitted from the title or the text of a book about bioenergetics and energy expenditure.

I am not a physicist. In fact I first went to college to become a football coach. That vocational choice began to deteriorate when taking the mandatory anatomy and physiology courses required of all physical education majors. This information was exciting, my interest in physical education began to wane.

During sophomore year, I answered an advertisement in the school newspaper requesting research subjects. The request was made by a master’s student who was correlating the presence of the anaerobic threshold with the rating of perceived exertion (RPE) during treadmill running to exhaustion (it happens at the point when the subject perceived that the work being performed was “somewhat hard” to “hard”). This was a cool endeavor! So cool that I asked the study’s author if it were possible to hang out and help. Soon, I was calibrating the equipment in addition to helping with subject testing. It was this experience more than anything else that defined my chosen career path.

During my senior year internship, I met Dr. La Von Johnson, who offered a full scholarship to obtain a master’s degree in sports medicine. Dr. Johnson remains the most influential of all my academic acquaintances, a true teacher, professor, mentor, and friend. Our mutual academic interest in strength, speed, and power planted a seed that still grows today (thank you, Dr. Johnson!).

With graduate school supposedly complete, I entered the workforce, a manager or exercise programmer for a fitness center. It soon became clear that this was not going to be a career. Later, at yet another fitness facility, more and more time was spent in academic libraries doing “armchair research.” A short year-long stint with an author who was writing fitness and nutrition-related material soon followed. As a research editor, I found myself spending even more time in armchair research-related endeavors. My future was seemingly in view: Do not just read about research, do it.

The next step, it seemed, was to become something of a respected authority in the exercise sciences. Becoming a Ph.D. scientist should have something to do with that! A doctoral degree was needed to help accomplish this. Surprisingly, every school I applied to rejected my admission requests. Although painful at the moment, these academic institutions were correct in doing so. The educational background I had chosen emphasized exercise as a human behavior, motivating or instructing others on how to properly train. I was attempting to get into Ph.D. programs that were built on the more basic sciences, where exercise was used as a model or tool to study human physiology. Simply put, I was not adequately trained to become an authority in exercise science.

I was not alone on the preliminary path I had chosen. Now as a college professor, students routinely enter my office with an agenda of avoiding academic challenge, choosing classes that ignore a second semester of chemistry, a full year of organic chemistry and not even considering biochemistry, molecular biology, and cell physiology. A desperation phone call to a world-renowned exercise physiologist, whom I had never met, helped me through my “why didn’t I apply myself” crisis. As an armchair researcher, I had read many of his professional publications and was quite shocked that he took my phone call. Dr. Phil Gollnick (1935–1991) convinced me to go back to school to get another master’s degree, this time with an emphasis on science and research. And so at the age of 27 I did.