Exercise Physiology Test 3
How does ATP release its energy stores? Is oxygen involved in this process?
ATP hydrolysis (ATP reacts with H2O in enzymatically driven process [ATPase]). To release energy stored in phosphate bonds. O2 is not required for hydrolysis of ATP.
What are the end products of aerobic metabolism?
ATP, H2O, and CO2
Does increased PO2 (above 100 mm Hg) increase O2 saturation in healthy individuals?
No, and there is no increase in facilitation of exercise recovery.
Can exercise stop the decline in BMR?
No, but it can offset it: 1.1-Ib gain in FFM increases RMR 7-10 kcal/day 2. effect equal for endurance and resistance training.
Is there high risk of injury to the pulmonary system during cold-weather exercise?
No, cold ambient air is warmed as it passes though conducting zones. No risk even in extremely cold temperatures.
Is lactic acid a waste product?
No, it can be metabolized as an energy source.
Is FVC or MVV related to VO2max?
No, there is little relationship between diverse lung volumes and capacities and exercise performance in healthy individuals.
What is a strong predictor for performance for athletes with similar VO2max?
OBLA, it is the ability of the athlete to sustain highest workload (% VO2max) without accumulation of lactic acid.
What factors affect obesity?
Obesity is a complex process that is influenced by genetic, physiological, environmental, and behavioral factors.
For water based aerobic exercise what special precaution must be kept in mind for asthma patients?
Preferably use non-chlorinated pools.
Residual Lung Volume (RLV)?
Volume in lungs after max expiration. Men 1200, Women 1000
Total Lung Capacity (TLC)?
Volume in lungs after maximum inspiration. Men 6000, Women 4200
Functional Residual Capacity (FRC)
Volume in lungs after tidal expiration. Men 2400, Women 1800
What is Tidal Volume (TV)? what are the average values in mL?
Volume inspired or expired per breath. Men 600, Women 500
What is minute ventilation? How is it calculated?
Volume of air breathed each minute (VE), Tidal Volume x Respiratory Rate. 0.5 L x 12 breaths/min. = 6 L/min
According to FITT recommendations, what type of exercise should a patient with COPD engage in?
Walking and/ or cycling
What kind of environments are preferable for patients with asthma?
Warm, humid, ideally non-chlorinated. Avoid cold and dry conditions.
What is ventilatory equivalent? What are the normal values?
Ventilatory equivalent is VE/ VO2, normal values are ~ 25 L per min. in adults.
What intensity of exercise requires greater reliance on CHO?
Higher intensity exercise, CHO is twice the rate of fats and proteins and can rapidly supply ATP.
What term can lactate threshold, VT, and OBLA be interchangeably used for and what do they predict?
"Anaerobic threshold" which is an independent predictor of endurance performance.
What does lactate threshold describe?
Highest O2 consumption or exercise intensity with less than a 1.0 mM/L per liter increase in blood lactate above resting level.
What is a good initial goal for weight loss in obese Pts? How could this be achieved?
1. Reduce body weight 10% within a 6 month time frame. 2. Rate of loss 0.5 to 2 Ibs./wk or 1% 3. Create a moderate energy deficit: decreases calories and increase activity.
What are the values for V/Q at rest, light and strenuous exercise?
1. Rest: 4.2 L/min / 5.0 L/min = .84 2. Light exercise ~ .8 3. Strenuous exercise ~ 5.0, 100 L/min (V) / 20 L/min (CO) = 5
How do you estimate resting daily energy expenditure (RDEE)?
1. 1 MET x 3.5 x BW (kg) / 1000 x 5 2. Harris-Benedict Equation : -Women: BMR=655.1 + (4.4 x weight in Ibs) + (4.7 x height in inches) - (4.7 x age) -Men: BMR= 66.5 + (6.2 x weight in Ibs) + (12.7 x height in inches) - (6.8 x age) 3. Body weight (Ibs) x 11 4. PAL equations.
Describe and give the results of the Anderson and colleagues study on lifestyle physical activity.
1. 16 week randomized controlled trial with 1-yr follow-up 2. 40 obese women (BMI 32.9) 3. Randomized to standard diet and behavioral intervention and either programmed aerobic exercise or lifestyle physical activity 4. Aerobic exercise: 3 step aerobic classes per week (450-500 kcal/class), instructed on developing long-term structured exercise program. 5. Lifestyle physical activity: accumulate 30 minutes of moderate-intensity physical activity on most days of the week. Taught to incorporate short bouts of activity into daily routine-walk instead of drive short distances, take the stairs instead of the elevator. 6. By 16 weeks performing 237 kcals/day on 4.7 days/wk ~ 1100 kcals/wk. 7. Resuts: both groups experienced weight loss but the lifestyle group remained steady while the aerobic group began to see an increase in weight gain. See slide 48.
Anaerobic systems provide energy for all out exercise for what amount of time? What types of exercise primarily use this system?
1. 2 min. 2. Speed and power events (high intensity, short duration)
What are the steps of total energy transfer from glucose?
1. 2 net ATP from glycolysis 2. 2 NADH from glycolysis produce 4 ATP 3. 2 NADH from coversion of pyruvate to acetyl-CoA yields 6 ATP 4. 6 NADH from citric acid cycle yield 18 ATP 5. 2 FADH2 from citric acid cycle yields 4 ATP 6. 2 ATP from breakdown of acetyl-CoA 7. Total ATP= 36 8. CO2 and H2O produced.
What is BMI?
1. A non-judgemental measure that relates weight to height 2. Correlates with risk of morbidity and mortality 3. In average (non-athletic) individuals moderate correlation with body fat.
Give the description and results of the Levine and colleagues experiment evaluating non-exercise activity thermogenesis (NEAT).
1. ADL, ambulation, fidgeting, posture, and spontaneous muscle contraction. 2. Overfeeding study NEAT directly predicted resistance to weight gain over 8 weeks 3. Lean sedentary subjects stand and ambulate 152 minutes more per day than obese subjects- energy cost ~350 kcal/day 4. "The potential of NEAT is sufficiently great to substantially contribute to energy balance."
How is energy released from fat?
1. Adipocytes (fat cells) and intramuscular fat goes through lypolysis (hydrolysis). 2. In mitochondria, FFA's converted to Acetyl-CoA by beta-oxidation. 3. Acetyl-CoA enters citric acid cycle 4. Process only occurs under aerobic conditions 5. Each 18 carbon FFA produces 147 ATP
What is Hgb saturation and PO2 in alveoli? In tissue?
1. Alveoli: Hgb ~ 98% O2, PO2 100 mm Hg 2. Tissue: Hgb ~ 70% O2, PO2 40 mm Hg
Give the criteria for exercise testing patients with COPD.
1. Assess CRF, pulmonary function, and determine arterial blood gases or arterial oxyhemoglobin saturation (SaO2) 2. Perceptions of dyspnea should be measured during exercise testing using Borg CR10 Scale. 3. Smaller increments and slower progression of workload due to functional limitations and early onset of dyspnea. Durations between 5 and 9 min in Pts with severe and very severe disease. 4. Use of bronchodilator therapy may be beneficial. 5. Due to ventilatory limitations, prediction of VO2peak based on age-predicted HRmax may not be appropriate. 6. 6-min walk test valuable for for assessing functional exercise capacity in individuals with more severe pulmonary disease. 7. Terminate test with more severe arterial desaturation (SaO2 less than or equal to 80%) 8. Arm ergometry may result in increased dyspnea that may limit intensity and duration of activity.
What makes up total daily energy expenditure (TDEE)?
1. Resting metabolic rate 60-75% 2. Thermogenic effect of food ~10% 3. Physical activity 15-30%
Give the guidelines for exercise testing Pts with asthma.
1. Assess cardiopulmonary capacity, pulmonary function (preexercise and post), and oxyhemoglobin saturation via noninvasive methods (pulse oxymeter). 2. Administration of inhaled bronchodilator prior to testing can prevent exercise-induced bronchochonstriction, thus providing optimal assessment of cardiopulmonary capacity. 3. Use age predicted HRmax for setting exercise intensity or VO2peak may not be appropriate because of possible ventilatory limitation to exercise. 4. Evidence of oxyhemoglobin desaturation greater than or equal to 80% should be used to determine termination criteria. Measure exertional dyspnea using the Borg CR10 scale or 4 Point Scale (see p. 132, 248) 5. Develop wording to describe Pt's level of breathlessness: 0-10 scale.
What impact can exercise have on asthma? What is Exercise-Induced Asthma (EIA)?
1. Asthma symptoms can be provoked by or worsened by exercise, which may contribute to reduced participation and deconditioning. 2. EIA= bronchospasm and mucus secretion occurs during or within 5-15 minutes following exercise.
How is CO2 transported from tissue through blood?
1. CO2 in solution combines with H2O to form carbonic acid (H2CO3) catalyzed by carbonic anhydrase. 2. Carbonic acid ionizes into hydrogen ions and bicarbonate ions (H+ and HCO3-). 3. H+ is buffered by Hgb to maintain pH. 4. O2 has higher affinity for Hgb, which displaces CO2 from Hgb in alveoli. 5. CO2 expired during exhalation.
What should the therapist keep in mind when exercise testing obese patients?
1. Comorbidities: may increase risk classification. 2. Consider medication effects on exercise response. 3. Musculoskeletal and/or orthopedic conditions may require modification 4. consider cycle leg ergometer (with and oversized seat) versus treadmill. 5. Equipment must be adequate to meet the weight specifications of individuals. 6. Appropriate cuff size for measuring BP.
Give the steps of the Citric Acid (Krebs) Cycle.
1. Continuation of glycolysis under aerobic conditions 2. 2 Pyruvate converted to 2 carbon acetyl-CoA 3. Acetyl-CoA enters the Krebs Cycle 4. Hydrogen oxidized for passage to NAD+ and FAD and transported to ETC. 5. ATP produced through process of oxidative phosphorylation. 6. Fatty acids (beta oxidation) and some amino acids can enter the Krebs cycle.
How does recovery O2 consumption fill the needs of the body post-exercise?
1. Differs depending on intensity of exercise session. 2. Always in excess to resting value to repay O2 debt. 3. Chemical and physiologic alterations during exercise require additional O2 consumption to return metabolic systems to baseline. 4. More than just "repayment" of O2 debt- repayment (fast component) primary process of restoring anaerobic energy system (PCr and conversion of lactate to pyruvate).
Under anaerobic conditions (high-intensity exercise), what happens to muscle with lactate accumulation?
1. During anaerobic conditions lactate accumulates in muscles and blood. 2. Increased acidity inactivates key enzymes and impairs muscle contractility. 3. Results in pain, fatigue and decreased exercise intensity.
Give the steps of ETC.
1. During cellular oxidation, hydrogen in released from CHO, fat, protein by reactions involving substrate specific enzymes (dehydrogenases) 2. Coenzymes NAD+ and FAD accept hydrogen electron (and their energy) and carry them to ETC. 3. Cytochromes serve as electron carriers in ETC 4. Electrons transferred down chain and accepted by O2 (reduction). 5. energy gradient created which powers formation of ATP. 6. ETC removes electrons from an electron donor (NADH or FADH2) [oxidation] and transfers to a terminal electron acceptor (O2) [reduction] via series of redox reactions (cytochromes) 7. ETC coupled with creation of a proton gradient across mitochondrial inner membrane- captured energy pumps protons across membrane to create electrochemical concentration gradient. 8. Resulting transmembrane proton gradient is used to power synthesis of ATP from ADP and Pi via ATP synthesis.
How is an endurance- trained individual better able to adapt to oxygen debt.
1. Endurance trained individuals achieve steady state more quickly than untrained individuals. 2. Trained persons require less anaerobic metabolism 3. Oxygen debt is repaid through rephosphorylation of creatine (PCr) and lactic acid is metabolized into pyruvate.
What are the energy cost considerations for swimming?
1. Energy cost is to maintain buoyancy and overcome drag 2. Mechanical efficiency is 5-9.5% compared to 20-25% for walking/running 3. Drag forces (impede forward movement) 4. Cold water creates thermal stress (body must maintain core temp) and adds additional energy cost (optimal temp is ~82-86 F)
Why is lactate formed during the use of the short-term energy system?
1. Energy demands "outstrip" muscle's capacity to regenerate ATP aerobically. 2. Uses back up of NADH and FADH2 (hydrogen electrons) 3. Pyruvates accepts hydrogen and forms lactate= decreased Ph.
What happens during anaerobic glycolysis?
1. First stage of glucose breakdown. 2. Occurs in cytosol (outside mitochondria). 3. Rapid energy transfer that does not require oxygen (anaerobic). 4. Glucose is oxidized (hydrogen electrons removed) 5. Glucose is cleaved into 2 pyruvate molecules- pyruvate enters citric acid cycle or converted to lactate (if inadequate O2) 6. 2 net ATP produced 7. Can fuel maximum effort ~90 sec.
What is the difference gross and net energy expenditure?
1. Gross energy cost= total energy cost of an activity including resting energy expenditure. 2. Net energy cost= true cost of activity (gross energy cost minus resting energy expenditure).
How should the therapist assess EIA prior to exercise testing.
1. High intensity exercise (~80% of predicted HRmax or 40-60% of measured or estimated maximal voluntary ventilation) may be facilitated by inhalation of cold dry air. 2.Followed be spirometry at 5,10, 15 and 20 min. A decrease in FVC/FEVI ratio > 10% confirms the diagnosis.
What 3 metabolic systems are responsible for producing ATP?
1. Immediate energy- ATP and phosphocreatine: fuels maximum exercise for ~10 sec. 2. Short-term energy- Anaerobic glycolysis: fuels maximum effort for ~90 sec. 3. Long-term energy- Oxidative Phosphorylation (aerobic): fuels activity and exercise > 3 min.
What are the results of a 5-10% weight loss in obese individuals with type 2 diabetes, hypertension, or dyslipidemia?
1. Improved glycemic control 2. Reduced blood pressure 3. Improved lipid profile
Do pulmonary factors, in general, affect VO2max?
No
Give the exercise prescription for weight management.
1. Increased daily activities and reduce sedentary time 2. Accumulate at least 30 minutes of moderate intensity physical activity on most, preferably all days of the week (brisk walk at 3-4 MPH, consider short bouts) 3. Structured exercise such as swimming, jogging, bicycling, aerobic dance, aerobic sports as appropriate- Moderate to vigorous intensity for at least 20 min on 3 days/wk. 4. Incorporate a variety of activities such as strength training and flexibility exercises as become ready (or start with resistance training). 5. Accumulating 60 minutes or more of at least moderate-intensity activity on 5 or more days/wk is an appropriate long-term goal (> or = 2000 kcals). 6. Progress at rate that minimizes risk of injury, metabolic complications, and adverse behavioral consequences (i.e., relapse)- 1-2 years is appropriate.
What are some general pulmonary adaptations that occur due to aerobic training?
1. Increased maximal exercise ventilation. 2. Reduced ventilatory equivalent for oxygen (VE/VO2) (adaptions highly specific to type of exercise and muscle groups trained, decreased lactate production, ergo reflex??) 3. Higher intensity of exercise before reaching ventilation threshold. 4. Enhanced respiratory muscle endurance.
What are the benefits of exercise for Pts with Cystic Fibrosis?
1. Increases functional capacity and VO2 2. Improved cardiopulmonary efficiency at submaximal workloads. 3. Decrease oxygen consumption,ventilation, HR and RPE. 4. Increased ventilator muscle endurance. 5. Enhanced mucus clearance. 6. Delayed deterioration in pulmonary function.
What is involved in the process of lactate formation?
1. Insufficient O2 availability with high-intensity exercise 2. ETC cannot process all NADH 3. NAD+ is required for continued glycolysis 4. Excess H combines with pyruvate to form lactate temporarily oxidizing NADH to NAD+ 5. anaerobic glycolysis continues
What is Phosphocreatine? What is its purpose in the cell?
1. Intracellular high-energy phosphate compound. 2. Allows anaerobic resythesis of ATP- provides for an immediate source of energy in absence of adequate oxygen supply. 3. Cells store ~4-6 times more PCr than ATP. 4. Able to supply ATP very rapidly with sustainability of ~10 sec during maximal effort.
Describe the lactate shuttle process in light of lactate formation.
1. Lactate shuttle-lactate can be converted to pyruvate by other tissues 2. pyruvate converted to acetyl-CoA 3. Acetyl-CoA enters citric acid cycle and undergoes oxidative phosphorylation.
What are the special considerations for Pts with Cystic Fibrosis?
1. Malnutrition and body composition changes. 2. Increased infection risk- monitor closely. 3. Multiple medications: Inhaled bronchodilators (tachycardia), oral and inhaled glucocorticoids (myopathy, osteoporosis, tendinopathy) supplemental oxygen. 4. Testing and exercise performance improved by airway clearance techniques and bronchodilator therapy. 5. Increased risk of pneumothorax: avoid Valsalva maneuver and heavy weights.
What determines anaerobic threshold?
1. Muscle fiber type (high percentage of type 1) 2. capillary density 3. Mitochondria size and number 4. Oxidative enzyme concentration
Describe the setpoint theory.
1. Ob gene codes for leptin, which is synthesized and released by fat cells- Fat hormone that communicates with hypothalamus 2. Leptin regulates appetite and metabolism 3. Weight loss reduces leptin levels, thus stimulating appetite and slowing metabolism.
What precautions should the therapist keep in mind when working with obese patients?
1. Obese clients may be more susceptible to injury, fatigue, overheating/dehydration 2. Increased prevalence of comorbidities: diabetes, HTN, osteoporosis, heart disease (screen)
Describe the Cori cycle in light of lactate formation.
1. Once sufficient O2 available NAD+ oxidizes lactate (picks off hydrogen) resulting in reformation of pyruvate 2. NADH can enter ETC for ATP production and pyruvate oxidized for energy (citric acid cycle) or converted to glucose (gluconeogenesis) or to glycogen for storage.
How is energy released from protein?
1. Process of deamination - nitrogen removal from amino acid occurs in the liver and muscles (elimination of nitrogen (ammonia) as urea by kidneys. 2. Carbon skeleton can be converted to pyruvate, or acetyl-CoA and enter citric acid cycle for oxidation.
What qualities of physical activity support losing and maintaining healthy weight?
1. Promotes weight loss- 2-5 lbs for most adults 2. decreases abdominal fat-reduces fat where it is most dangerous. 3. increases cardiorespiratory fitness- Fitness is associated with decreased mortality regardless of body weight. 4. Independently reduces CVD risk factors- improved risk factors even without weight loss 5. Promotes maintenance of weight loss- this is the most important aspect of activity.
What are the benefits of fat as fuel during exercise?
1. Provides large quantity of energy storage. 2. Light weight relative to energy content (glycogen stored with high water content. 3. Body stores ~ 12,000 g (500 CHO g) = 108,000 k/cals - enough fuel for over 40 marathons.
Since PT's are providers of health care, what approaches will support and guide care for obese patients.
1. Recognize individuals who are obese (at risk). 2 .Address obesity-related issues with their patients (health risks, causes). 3. Assess obesity-related limitations that might alter therapy (both processes and outcomes) 4. Tailor therapeutic regimens to meet the needs of individuals who are obese 5. provide health enhancing interventions and guidance in weight management.
What factors affect a-vO2 difference during exercise and training effects?
1. Redistribution of flow to active tissues during exercise. 2. Increased capillary density due to training increases surface area and O2 extraction. 3. Increased number and size of mitochondria. 4. Increased oxidative enzymes. 5. Overall vascular and metabolic improvements.
If Pt has an asthma episode when is it safe to resume exercise?
No exercise until symptoms and airway function has improved.
Give the basics of glycolysis.
1. Series of 10 enzymatically driven reactions 2. 2 ATP consumed in Phosphorylation of glucose 3. Phosphofructokinase is a rate-limiting enzyme- fast twitch muscle fibers (type II) contain large amounts of PFK. 4. Fructose 1,6-diphosphate splits into two 3 carbon molecules. 5. 5 successive reactions result in formation of 2 pyruvate molecules. 6. In process NAD is reduced to NADH and 2 net ATP are generated (steps 7-10).
What is gluconeogenesis? Lipogenesis?
1. Some amino acids (glucogenic) can be converted to glucose 2. Some amino acids (ketogenic) can be converted to lipids
What role do neurogenic factors play in ventilation?
1. Stimulation of ventilation at the onset (before?) exercise. 2. neural outflow from motor cortex. 3. Peripheral mechano- and chemo-receptors in muscles and joints. 4. Increased exercise intensity = important "fine-tuning" role of arterial H+ concentration, PCO2 and pH = PCO2 increases and pH decreases (lactate accumulation) = stimulation of peripheral chemoreceptors. 5. Neurogenic mechanism plays more prominent role throughout exercise.
What are some general benefits for ventilatory training?
1. Strengthening of respiratory muscles 2. Increase MVV 3. Decrease dyspnea in patients with pulmonary disease
Give the important characteristics of dyspnea.
1. Subjective distress to breathing 2. Response to elevated PCO2 levels, which activates inspiratory center increasing rate and depth of breathing. 3. Dyspnea during exercise places greater metabolic demand on the body.
How does resistance training support weight loss?
1. Supplemental to endurance exercise 2. Focus on improving muscular strength and endurance. 3. Additional health benefits such as improvements in CVD and DM risk factors and other chronic disease risk factors.
What are the secrets of successful maintainers for weight loss for the long term.
1. Using survey of over 3000 men and women maintaining an average weight loss of over 60 pounds for 6 years. 2. Limited curtain foods, limited quantity, counted calories and/or fat grams. -Healthy diet consistent with food guide pyramid -50% continue to count calories 3. Women 1400 kcals; Men 1800 kcals 4. 25% of calories from fat 5. Eat 5 times per day - eat breakfast! 6. < 1 fast-food meal per week, 2.5 meals out per week 7. 90% changed both diet and physical activity (only 10% were successful with diet alone) 8. 2800 calories in physical activity per week, 60-90 min.per day 9. Average of 3 hours of TV each week 10. 75% weighed at least once per week
According to FITT recommendations, at what intensity should a patient with COPD exercise?
1. Vigorous (60%-80% of peak work rates): Shown to result greater physiologic improvements (e.g., reduced minute ventilation and HR at a given workload) 2. Light (30%-40% of peak work rates): improvement of symptoms, health related quality of life, and performance of ADL 3. Intensity may be based on a dyspnea rating of between 4 and 6 on the Borg CR10 Scale.
What factors influence health risk with obesity?
1. Waist circumference: women > 35 inches, men > 40 inches 2. Asses for other risk factors: CVD, diabetes, HTN, dyslipidemia, family history, age, physical inactivity. 3. Body compisition: women >30% fat, men >25% fat
What role does chemical control play in ventilation during exercise?
1. changes in PO2 and PCO2/H+ do not entirely account for increased ventilation (Neurogenic factors).
What are some negative consequences of water loss due to the warming and humidifying air during respiration in cold temperatures?
1. dehydration 2. Dry Mouth 3. Irritation of respiratory passages 4. Triggers bronchochonstriction in asthma and COPD sufferers.
What should the therapist emphasize in recommending physical activities for obese patients?
1. low impact activities 2. moderate intensity 3. short bouts 4. warm-up and cool-down 5. hydration
What is the rate of energy supply for the short-term energy/lactic acid system?
1/2 of immediate energy system, predominate system for 30 to 90 sec.
How much O2 is usually attached to Hgb after extraction?
15 mL O2/dL = 75% O2 saturation = large reserve capacity
What amount of protein is used for energy needs?
2%-5%, does not play an important role for meeting energy needs of the body. Gluconeogenesis from protein becomes more important as CHO is depleted during exercise.
Obesity has the same association with chronic health issues as does . . .
20 years of aging
What amount of lactate production can sprint/power athletes achieve? What mechanisms allow this to be a functional adaption?
20-30% higher than untrained 1. Improved motivation 2. Increased intramuscular glycogen stores and usage- allows for increased glycolysis. 3. Activation of type II muscle fibers. 4. Increased glycolytic enzymes- training increases ~20%
Give the basic principles of weight loss for reductions of 250, 500, and 1000 cal/day per week.
250 cal/day x 7 days = 1750 kcal or 1/2 pound of weight loss per week. 500 cal/day x 7 days= 3500 kcal or 1 pound of weight loss per week. 1000 cal/day x 7 days= 7000 kcal or 2 pounds of weight loss per week.
When does walking economy begins to decrease?
3 mph, relationship between walking speed and O2 consumption becomes non-linear.
What are the FITT recommendations for exercise time and obese patients?
30 min/day (150 min/wk) progressing to 60 min/day (300 min/wk). Accumulation of exercise (10 min bouts) is effective.
When should Pts with asthma administer bronchodilators prior to exercise?
30 minutes before, important for prevention or treatment of EIA.
Intracellular and extracellular fats supply how much energy for exercise?
30%-80% of energy for physical exercise
1 pound of weight loss = ?
3500 calories, ~75% fat weight and 25% lean tissue
What is the rate of energy supply for the immediate energy (ATP-PCr)?
4-8 times faster than aerobic metabolism, energy is depleted in ~10 sec
How many kcals are burned for every L of O2?
5 kcals
At what speed does running become more economical than walking?
5.0 mph
Aerobic metabolism is responsible for how much of ATP resynthesis?
90%
What are the FITT recommendations for exercise frequency and obese patients?
> or = 5 days/wk, maximize caloric expenditure.
Are values on exercise equipment accurate?
?
the aerobic system predominates for which activities?
Activities > 3 min. = endurence (low intensity, sustained duration).
What direct benefits do endurance training adaptations have on fat oxidation and glycogen?
Adaptations allow for greater oxidization of fat which creates a glycogen sparing effect.
What are the FITT recommendations for exercise type and obese patients?
Aerobic physical activity, low impact activities preferred. AS part of a balanced program include resistance training and flexibility exercise should be incorporated.
What are the FITT recommendations for exercise progression with asthma Pts?
After 1st month, if tolerated, greater health benefits may be gained by increasing intensity to ~70% VO2peak. Progress to 40 min. a day and frequency 5 days a week.
What were the results of the study using 56 obese women given exercise program 40 min, 5 days/wk, randomly assigned to long-bout (40 min continuous) and short-bout (10 min bouts x 4)?
After 20 weeks short bout group: 1. performed more minutes of activity 2. Exercised more days of the week 3. Lost more weight
At rest how much O2/dL is carried in the arteries? during venous return?
Arterial blood carries 20 mL O2/dL, venous blood 15 mL O2/dL. Tissues extract 5 mL O2/dL
What are the FITT recommendations for exercise frequency with asthma Pts?
At least 2-3 d/wk
What are the FITT recommendations for exercise time with asthma Pts?
At least 20-30 min/day
According to FITT recommendations, at what frequency should a patient with COPD exercise?
At least 3-5 days/wk
When does VT occur?
At ~55% VO2max
What is the average blood lactate threshold for an untrained individual?
Blood lactate begins to accumulate ~55% maximal aerobic capacity.
What directly influences energy cost during walking and running?
Body weight and % grade (elevation)
If CHO is depleted, how does this affect fat oxidation?
CHO is a primer for fat oxidation, depleted CHO causes an incomplete breakdown of fatty acids and ketones.
How is CHO important for tissue maintenance?
CHO spares protein for tissue maintenance, growth and repair
How do you calculate VO2?
CO x a-vO2
What does the balance between ADP and ATP regulate?
The breakdown of macronutrients needed to resynthesize ATP by activating key enzymes (negative feedback).
What is the blood lactate threshold for an endurance athlete? What metabolic adaptations from training facilitate this?
Can stay at a steady state at > 80% of maximum capacity (increased capacity to generate ATP aerobically) 1. More slow-twitch (type I) muscles fibers 2. Training adaptations in blood flow, glycolytic enzymes and greater number of mitochondria.
What factor is the primary determinant VO2max?
Capacity of the cardiovascular system.
VO2max requires integration of which systems?
Cardiovascular, pulmonary, and neuromuscular function.
Can athletes alter their breathing patterns to enhance performance? Can patients with lung disease alter breathing patterns to increase ability to breath?
Changes in breathing pattern do not enhance exercise performance. However, breathing control techniques and respiratory muscle training are important treatment protocols for those with lung disease.
What is asthma?
Chronic inflammatory disorder characterized by episodes of bronchial hyperresponsiveness, airflow obstruction, wheezing, dyspnea, chest tightness, and coughing.
What is COPD?
Chronic, irreversible airflow obstruction with severity determined by degree of pulmonary dysfunction. 1. Bronchitis-chronic productive cough for 3 months in each of two successive years. 2. Emphysema- permanent enlargement and destruction of air spaces distal to terminal bronchioles.
What are the 3 components of aerobic metabolism?
Citric acid cycle, electron transport chain, oxidative phosphorylation.
What is a metabolic equivalent?
Common method of comparing O2 consumption and energy expenditure during physical activity to resting levels (represent multiples of resting metabolic rate). Describes absolute intensity of activity and exercise. 1. 1 MET = RMR 2. 1 MET = 250 ml O2/min (men), 200 ml O2/min (women) 3. 1 MET = 3.5 ml O2/kg/min 4. 1 MET = 0.0175 kcal/kg/min
What is the possible VO2 at rest for someone with COPD?
Cost of breathing as high or > 40% VO2max. This severely limits exercise capacity of Pts with COPD.
Since COPD may cause dyspnea with upper extremity actions, how can a Pt improve functional abilities and ADL's?
Focus on shoulder girdle when performing resistance exercise to improve functional abilities and ADL's.
What do most COPD patients accurately and reliably produce as a target to regulate and monitor exercise intensity? What other measure should be added to this for accurate intensity monitoring?
Dyspnea rating, HR
What is the effect of body mass on energy cost?
Energy cost of weight-bearing exercise increases directly with body mass.
What are the strategies helpful for increasing energy expenditure and weight loss?
Energy expenditure > energy intake = weight loss 1. Decrease time spent in sedentary activities 2. increase lifestyle physical activities 3. Participate in enjoyable structured exercise 4. Accumulate at least 30 min of mod intensity physical activity on most, preferably all, days of the week- Long term goal 60 min (90?)
What is metabolism?
Energy necissary to maintain vital functions (metabolic processes).
What is economy of movement?
Energy required to maintain a constant velocity of movement. 1. Goal= achieve lowest oxygen consumption to perform same amount of work (same running speed with less O2 use. 2. More skilled athletes perform the same activity with a reduced energy requirement 3. Related to difference in muscle fiber type and physiological adaptations 4. Highest economy of movement, not VO2max distinguishes running performance.
What benefits are gained for training for short-term all out exercise?
Enhances capacity to generate energy anaerobically: 1. greater ability to use glycogen (glycolytic enzymes), produce lactate, and tolerate lactate accumulation (motivation) 2. No training effect to buffer acid accumulation.
Exhaustive endurance exercise requires a greater dependence on which fuel(s)?
Fat and protein use increases as CHO is depleted. Neither are efficient fuels.
Lower intensity exercise depends on a greater percentage of which fuel?
Fat, ~50%
What is VO2max closely related to?
Functional capacity of the heart- cardiac output=stroke volume x heart rate.
What other factors affect anaerobic capacity?
Gender: true biological difference between males and females (hormonal, cross sectional area, fiber type) Genetics: strong influence on muscle fiber type.
What is Cystic Fibrosis?
Genetic disease causing excessive, thick mucus that obstructs the airways (and other ducts) and promotes recurrent and ultimately chronic respiratory infection. It is an obstructive pulmonary disease that also affects the GI and respiratory systems.
What is meant by the term hitting the wall?
Glycogen depletion. Very limited stores of glycogen = ~500 g CHO storage coincides with ~ 20 mile mark in a marathon. Considerations: Fat supplies energy needs- slower rate of energy release + CHO is primer for fat metabolism. CHO needed for optimal nervous system function.
What is an effective way to increase intensity during walking without increasing speed?
Increase elevation, this can also reduce risk of injury
What are the recommendations for protein intake for exercise needs?
Increased requirements easily met with current guidelines: 1.5 g per kg body weight. For 3,000 kcal intake an athlete will require 105 g or 420 kcals = 15% of total kcals (10 oz. meat, 2 servings of dairy, 6 grains, 3 servings of vegetables.)
What happens to minute ventilation during exercise?
Increases dramatically- Avg. person ~ 100 L/min (2.5 L x 40 breaths/min = 100 L/min). Athletes= up to 150- 200 L/min
Why should therapists caution their patients about long term use of oral corticosteroids?
Increases risk of myopathy, osteoporosis, and tendonopathy.
According to FITT recommendations, at what amount of time should a patient with COPD exercise?
Individuals with COPD may only be able to exercise at specified intensities for only a few minutes: 1. Intermittent exercise may be used initially until exercise at sustained higher intensities and durations tolerated. 2. Shorter periods of vigorous intensity exercise separated by periods of rest (i.e., interval training) shown to result in improvement in symptoms.
What determines energy cost of physical activity?
Intensity, duration, and amount of muscle mass activated.
How does mobilization and oxidation of fat for fuel support high-intensity exercise?
It actually does not support high-intensity exercise
Does ventilation limit maximum exercise performance?
It does not.
What happens to a-vO2 difference during exercise?
It increases to 15 mL O2/dL. This leaves 5 mL O2/dL or 25% O2 saturation to Hgb.
What kind of relationship is there between O2 consumption and walking speed?
It is a relatively linear relationship between 2-3 mph
What are the FITT recommendations for exercise warm-up with asthma Pts?
Light to moderate intensity warm-up initiates a refractory period= 15-20 min warm up benefits for ~ 2 hours.
How does MVV compare to ventilation during maximal exercise?
MVV averages 25% higher than ventilation. Indicates significant reserve capacity.
How does exercise benefit persons with COPD?
Mainly through adaptations in musculoskeletal and cardiovascular system that reduce stress on the pulmonary system.
What is VO2max?
Maximal amount of oxygen a body can consume during prolonged, intense exercise. It is an important determinant of endurance performance, cardiovascular fitness, health and quality of life.
Expiratory reserve volume (ERV)?
Maximum expiration at end of tidal expiration. Men 1200, Women 800
Inspiratory reserve volume (IRV)?
Maximum inspiration at the end of tidal inspiration. Men 3000, Women 1900
Forced Vital Capacity (FVC)?
Maximum volume expired after maximum inspiration. Men 4800, Women 3200
Inspiratory Capacity (IC)?
Maximum volume inspired following tidal expiration. Men 3600, Women 2400
What are the normal ranges for MVV?
Men: 160 L/min, Women: 100 L/min, Endurance: > 180 L/min
What are the FITT recommendations for exercise intensity and obese patients?
Mod to vig intensity, progression to vig intensity exercise may increase benefits but therapist must be cautious of increased injury risk and burnout.
What is the difference between obesity and overweight?
Obesity- an excessive accumulation of fat beyond normal for age, gender and body type. Associated with significant health risk. Overweight- is excessive weight for height. May or may not be associated with increased health risk depending on body composition.
What is ventilatory threshold (VT)?
Point at which pulmonary ventilation increases disproportionately with O2 consumption during exercise. CO2 generated by buffering of lactic acid causes an increase in VE in excess of O2 consumption.
What role do pulmonary adaptions play in improving endurance performance?
Probably only a minor role.
Why is it important for individuals to develop their own "style" of breathing during exercise?
Provides effective alveolar ventilation, ie. maintenance of PO2 and PCO2 to meet metabolic demands.
When is supplemental O2 indicated for patients with COPD?
Pts with PaO2 = or < 55% or %SaO2 = or < 88% while breathing room air.
Why should a therapist include resistance training in an exercise prescription for Pts with COPD?
Pulmonary diseases and treatments put patients at increased risk for myopathy, osteoporosis, and tendinopathy. prescribe with appropriate.
What device should be used for testing oxyhemoglobin desaturation during exercise and why is this important for patients with COPD?
Pulse oximetry, it is recommended to test oxyhemoglobin desaturation during initial exercise programs to evaluate when exercise desaturation may happen and at what workload.
What is the ventilation-perfusion ratio (V/Q)?
Ratio of alveolar ventilation to pulmonary blood flow.
What special consideration should be given to asthma patients and resistance training?
Take caution if there is a history of glucocorticoid use which can increase risk of myopathy, osteoporosis, and tendinopathy
What is Maximum Voluntary Ventilation?
The evaluation of ventilitory capacity with rapid and deep breathing for 15 seconds. MVV= 15 second volume X 4 (=L/min)
Is resistance exercise superior to endurance exercise for weight loss?
There is no evidence that resistance exercise is superior to endurance exercise for weight loss, preventing loss of fat-free mass or decline in REE that occurs with diet-induced weight loss.
What difference is there between endurance trained and untrained individuals in static and dynamic lung function?
There is no significant difference between the two.
When minute ventilation increases, what happens to Tidal Volume?
Tidal Volume increases but rarely exceeds 60% VC
What happens to ventilation during light to moderate exercise?
Ventilation increases linearly with O2 consumption and CO2 production .
What are the BMI value classifications from underweight to extreme obesity?
Underweight <18.5 Normal 18.5-24.9 Overweight 25.0-29.9 Obesity I 30.0-34.9 II 35.0-39.9 Extreme Obesity III > or = 40
How should a patient, who is prone to dyspnea, be monitored during exercise?
Use dyspnea scale to monitor patient's exercise intensity and distress.
What happens to ventilation during strenuous exercise?
VE/VO2 can increase to 35 - 40 L of air per L of O2 consumed.
What is the criterion measure for cardiorespiratory fitness and aerobic endurance capacity?
VO2max
How is calculated?
VO2max = CO x A-VO2 diff
Onset of Blood Lactation Accumulation (OBLA) signifies . . .
When blood lactate increases to 4.0 mM/L. Represents maximum exercise intensity that a person can sustain for a prolonged duration.
Since patients with moderate to severe COPD may exhibit oxyhemoglobin desaturation with exercise, how should these patients be monitored during GXT?
With either partial pressure of arterial oxygen (PaO2) or % SaO2 during initial GXT.
What is the difference in VO2 between men and women?
Women are 10% lower than men.
What are the VO2max values for women as compared to men? What are some possible reasons for the difference?
Women have values 15-30% lower than men. Possible reasons include: differences in body composition, lower Hgb concentration.
What is a women's BMR as compared to men?
Women typically have BMR 5-10% lower than men.
Is energy cost of running a set distance similar for different speeds?
Yes, regardless of whether faster speed, shorter running time or slower speed, longer running time, energy cost will be ~100 kcal/mile.
What dyspnea rating on a scale of 1-10 is appropriate for exercise and COPD patients?
a rating between 4 and 6.
CHO is the macronutrient that can fuel higher intensity exercise through?
anaerobic glycolysis
Regardless of prescribed exercise intensity for Pts with COPD, the therapist should . . .
closely monitor initial exercise sessions and adjust intensity and duration according to individual responses and tolerance.
What is arteriovenous O2 difference (a-vO2)?
describes difference between O2 content and arterial blood and venous blood. Tissues extract 5 mL O2/dL, which make this difference the average a-vO2 at rest.
The guide to physical therapy practice acknowledges obesity as a risk factor for?
impairments in aerobic activity . . . and other impairments that can affect a person's ability to function at work, in the community, or at leisure. APTA anticipates increased PT involvement in management of obesity-related impairments, functional limitations, and disabilities
concerning BMR, an increase in body mass equals?
increase in BMR
What is the O2 cost of an individual at rest?
minimal cost of breathing, 3-5% VO2max
What defines an oxygen deficit?
quantitative expression of difference between oxygen consumed and the amount that would have been consumed had steady state been achieved at beginning of exercise.
What is the oxyhemoglobin dissociation curve?
relationship of O2 binding to with Hgb at various levels of PO2 (see slide 10). = % saturation
During maximal exercise what portion of total blood flow do respiratory muscles require?
significant portion, up to 15% VO2max. Competition for blood flow and oxygen. Goal is to achieve high VO2 and delay VT as long as possible.
What factor of the immediate energy system significantly effects performance?
the quantity of PCr
What are the FITT recommendations for exercise intenstity with asthma Pts?
~ at ventilatory anaerobic threshold or at least 60% VO2peak determined from progressive exercise testing with measurement of expired gasses.
What is the rate of VO2max decline starting at 25 and progressing? How does endurance training affect this decline?
~1% per year, endurance training can slow but not prevent the decline.
What is the rate of decline of BMR in adults?
~2-3% per decade in adults
