Exercise Is Medicine: Physiologic Benefits of Exercise

1. Exercise Is Medicine:Physiologic Benefits of Exercise Ajay N. Kiri, M.D. AAPNA Teleconference December 21, 2009

2. Outline of Seminar • Exercise Fundamentals • Ayurveda on exercise • Benefits of Exercise • Exercise Physiology • How Exercise Effects Aging • Counseling Patients On Exercise • Recommended Exercise Regimens • Exercise Related Resources

3. Purpose Of The Seminar • To teach the main types of exercise & their benefits • To understand the physiologic effects of exercise • To learn the most effective ways to recommend exercise to your patients • To learn what types of exercise protocols to recommend to your patients

4. Why Exercise Is So Important • A functional, fit body is the foundation of health • Exercising is the only way to get in shape (become fit) • “Without Health There Is No Happiness…” Thomas Jefferson

5. Exercise BasicsWhat Is Exercise? • Physical activity • Any body movement by the skeletal muscles that results in a substantive increase in resting energy expenditure • yard work, shoveling snow, sports, weight lifting • Leisure time physical activity • Sports like basketball or soccer • Scheduled exercise • Goal oriented activity: jogging or weight lifting • Improved fitness or physical performance • Weight management or better health

6. Main Types of Purposeful Exercise • Aerobic (with oxygen) • Continuous exercise w/elevated heart rate • Anaerobic (without oxygen) • Weight lifting, power exercises • Oxygen demand is greater than oxygen supply • Core strengthening/stability training • Flexibility training • Balance training • Sport specific training, ie agility, performance

7. What Is Fitness • Ability to do physical work over time, using the musculoskeletal & cardiovascular systems • Greater degree of fitness leads to reduced risks of overall disease & greater sense of well being & functionality

8. Age-adjusted mortality rates in healthy men categorized by level of fitness (Exercise capacity in METs) • Myers, J. Circulation 2003;107:e2-e5

9. How Exercise Impacts Health • Improves state of health & fitness • Helps manage body weight • Improves strength, stamina & energy • Improves libido and sexual performance • Improves alertness & concentration • Improves mood & promotes a positive attitude • Promotes restful sleep • Delays aging related physiologic changes

10. Patient Asks Why Exercise? • Makes you feel better • Makes you look better • Makes you feel better about yourself • Reduces risks of major diseases • Heart disease, diabetes, stroke, cancers • Leads to improvement in a great variety of diseases & negative health conditions

11. Ayurveda and Exercise • Ayurveda mainly works through nutrition and medications • Ayurveda recognizes the benefits of exercise at the physical, mental & spirit • Ayurveda’s exercise recommendations are similar to western medicine’s • From thousands of years of wisdom & experience

12. Ayurveda’s Views On ExerciseIts Physical Benefits • Enhanced circulation  • Enhanced energy, strength and vitality  • Enhanced flexibility and coordination • Good posture  • Increased ability to breathe deeper, infusing more prana into the system  • A feeling of lightness in the body  • Toned muscles and body  • Increased efficiency of the digestive system and a balanced appetite and metabolism  • Increased efficiency in eliminating toxins from the body

13. Ayurveda’s Views On ExerciseBenefits for Mind, Heart and Spirit • Enhanced mental alertness and agility  • Enhanced mental strength  • Enhanced focus and ability to concentrate  • Sense of emotional equilibrium  • Enhanced self-esteem and respect for one's body  • Self-awareness  • Enhanced ability to manage stress  • Freedom of spirit

14. Ayurveda’s Views On ExercisePrinciples to Follow • Do not exercise to the point of discomfort • Leads to excessive soreness, fatigue, injury & premature aging • Results in enjoyment of exercise & greater long term commitment to exercise program • Always breath through the nose • Concept of balaardh: use half your strength or capacity when exercising • If you maintain the exercise program, your exercise capacity will increase

15. Ayurveda’s Views On ExercisePrinciples to Follow • Exercise early in the morning to promote elevated energy levels all day • Do not exercise on a completely empty stomach or just after a full meal • To enhance circulation and the elimination of toxins, ayurvedic healers recommend that exercise be preceded by abhyanga, the ayurvedic warm oil self-massage

16. Dosha Specific ExercisesVata-Predominant Types • Ideal exercises incorporate slow movements for balancing vata • Slow dancing • Low impact aerobics • Tai chi • Leisurely swimming in warm water • Badminton • Walking and yoga

17. Dosha Specific ExercisesPitta-Predominant Types • Look for individual activities that require strength, focus and speed • Water, ice or snow based activities • Swimming, downhill skiing, rowing, surfing and water-skiing • Walking or jogging in a cool shady area • tennis and yoga

18. Dosha Specific ExercisesKapha-Predominant Types • Excel at activities requiring endurance and doggedness • They like team sports • Might not always be motivated to exercise, preferring a more sedentary lifestyle • Good balancing activities include distance walking or running, basketball, racquetball, football, aerobics, ice skating, cross country skiing and cycling

19. Exercise Physiology and Its Specific Benefits • Discuss benefits by body system and physiology • Cardiovascular • Respiratory • Endocrine • Musculoskeletal & overall body composition • Mental health • Aging related physiology

20. Cardiovascular Benefits of A Sustained Exercise Program • Strengthens the heart muscle • Improves blood flow (circulation) • Reduces risk of heart attack • If occurs, occurs later in life, less severe event • Lowers blood pressure • Promotes weight loss • Raised HDL (good) cholesterol • Lowers LDL (bad) cholesterol

21. Exercise PhysiologyCardiovascular Effects & Benefits • Benefit derived primarily from aerobic exercise • Changes occur to accommodate increased blood flow to skeletal muscles for increased oxygen requirements

22. Exercise PhysiologyCardiovascular Effects & Benefits • What happens when you exercise • Heart rate increases linearly with work rate • Stroke volume increases • Cardiac output increases • Blood flow to muscles improves • Blood pressure increases with exercise • Tissue oxygen extraction improves • Pulmonary ventilation increases

23. How Cardiac Output Increases • Cardiac output (CO)= HR x SV • Increase in heart rate leads to higher CO • Stroke volume increases from resting HR up to 50% of aerobic capacity • Enhanced venous return • Increasing force of contraction • Increased ventricular contractility (Frank-Starling mechanism) • Catecholamine mediated sympathetic stimulation • Increase in ejection fraction • EF = [SV/EDV] x 100 • SV may decrease at higher heart rates b/c of less diastolic filling time

24. Stroke Volume Increases Up to 50% Aerobic Capacity

25. Exercise conditioning leads to increased aerobic capacity (fitness) Ability to circulate blood and provide oxygen improves The heart muscles enlarges and becomes stronger Results in higher stroke volume Lower resting pulse Greater response (increase in cardiac output) to exercise Cardiovascular Effects of Exercise Conditioning

26. Cardiovascular Effects of Exercise Conditioning: Sedentary Man Vs World Class Athlete • Resting/maximal (exercise) heart rate • Sedentary man: 70/190 bpm • World class athlete: 45/190 bpm • Resting/maximal stroke volume • Sedentary man: 85/93 mL/beat • World class athlete: 136/184 mL/beat

27. Cardiovascular Effects of Exercise Conditioning: Sedentary Man Vs World Class Athlete • Resting/maximal cardiac output • Sedentary man: 6.1/17.7 L/min • World class athlete: 6.1/35.0 L/min • Arteriovenous O2 difference: rest/maximal • Sedentary man: 4.0/14.0 mL/dL blood • World class athlete: 4.0/16.0 mL/dL blood

28. How Exercise Lowers Blood Pressure • Aerobic exercise does this • Takes 3 months to have an effect • Last as long as exercise is continued • Results from • Stronger heart muscle • Improved vasomotor responsiveness • Blood vessels are able to “relax” when not exercising • Less effort for blood circulation

29. The Respiratory System • Pulmonary ventilation is typically not the limiting factor in maximal aerobic capacity • Minute ventilation increases 15 to 25 fold with increasing exercise/work • Via increase in tidal volume • Respiratory rate • Generally pulmonary respiration is directly proportional to O2 consumption and C02 production • Also increases with lactate production

30. Exercise & the Endocrine System • Exercise makes the metabolism more efficient, increase in enzymes for energy production • Increases insulin sensitivity • Improves type 2 diabetes • Combined with aggressive dietary changes can “cure” type 2 diabetes • Promotes weight loss

31. Aerobic Exercise & Energy Metabolism • Glucose is the preferred energy source • ATP (energy) generated via glycolysis & Kreb cycle • Comes from glycogen breakdown in liver and skeletal muscle; glycogenolysis • Fat stores are also mobilized for energy • Ratio of glucose:fat metabolism is initially 1:1, can change to 1:4 with prolonged submaximal V02 <60% intensity exercise, takes 90 minutes to reach this effect • Increased fat metabolism with low to moderate intensity activities after 10 minutes of steady state exercise • Proteins may also be broken down for energy if needed

32. Anaerobic Exercise & Energy Metabolism • Energy for a 400m sprint • 70% anaerobic (without oxygen) • ATP-CP creatine phosphate system • ATP generated by glycolysis • 30% aerobic • Kreb cycle in mitochondria • Continued conditioning will increase the lactic acid threshold • Improved anaerobic energy production

33. Lipoprotein Profile and Exercise • Researchers are unsure as to exact mechanisms that do this • Exercise may release enzymes that clear LDL from blood vessels and bring it back to liver for processing • Exercise is able to change the lipoprotein profile • Low density lipoproteins are bad • High density lipoproteins are good • Exercise reduces former, increases latter

34. Lipoprotein Profile and Exercise • Aerobic exercise is needed to improve lipid profile • Greater intensity exercise leads to greater improvement • Can lower LDL by 10 – 15% • Increase HDL by 20% • Combine efforts with nutritional changes

35. Exercise & the Musculoskeletal System • Exercise training results in improvements in muscle strength & size up to that required for exercise • Muscles adapt to increasing resistance load by hypertrophy • Increases in contractile proteins actin & myosin • Also there is gradual strengthening of tendons, ligaments and joints

36. Exercise & the Musculoskeletal System • Strength or resistance training (ie weight lifting) leads to greatest muscle mass gains • Leads to increased overall strength, power, joint stability, basal metabolism • Can also improve neuromuscular control

37. Strength Training is Rehabilitative For Joints & Muscles • Leads to restructuring of collagen fibers in tendons & ligaments • Strengthens resulting soft tissues & joints • Process takes time & requires consistent effort on the part of the pt • Refer to a qualified physical therapist when needed

38. Exercise and Bone Health • Bone is constantly remodeling via • Osteoblastic formation • Osteoclastic resorption • Process is affected by mechanical stresses • Exercise is a stimulus for skeletal adaptation • Bones become stronger with exercise • Leads to maintenance or increase in density • Reminder • Women begin to lose bone mass between age 30 – 35 • Rate of about 0.75% to 1% per year • Men begin to lose bone mass between age 50 – 55 • Rate of about 0.4% per year

39. Exercise and Bone Health • Once bone is demineralized, remineralization with exercise is a slow process • Slower than building strength • Be careful when working out elderly because of weak bones • Best to take calcium & Vitamin D supplements & exercise throughout life to prevent bone mass & density loss

40. Exercise & Mental Health • Exercise promotes positive changes in mood • Increases brain blood flow • Increase in nerve growth factors • Increases concentrations of neurotransmitters that support cognition • Dopamine, glutamate, norepinephrine, serotonin • Release of opioid like endorphins • Runner’s high

41. Exercise & Mental Health • Exercise is a very effective treatment for depression • Improvement in serotonin levels • Weight loss • Increased confidence & self worth • Improvements in other mental disorders are possible • improved cognition in dementia • Stress reduction in anxiety states

42. Exercise And Sleep • Exercise improve ability to fall asleep and remain asleep • When the physical body is exhausted it slips into REM more quickly & for a longer period of time • Muscles recovery during sleep & REM • Leads to more restful sleep & increased energy during the day

43. Exercise and Aging • Aging is inevitable • Some changes can be mitigated or ameliorated via • Exercise • Proper nutrition • Proper supplementation • Lifestyle factors: stress reduction, sleeping habits, weight management

44. Cardiovascular Changes With Aging • Are changes normal or due to cardiovascular disease • Maximal heart rate decreases with age • Decrease in pacemaker cells and responsiveness to stimulation • Maximal heart rate formula • 220 minus age

45. Cardiovascular Changes With Aging • Increase in interstitial fibrosis & calcium in myocardium • Collagen crosslinking and elasticity loss • Left ventricle hypertrophies • Cardiac output is 10 to 30% less at age 65 than at young adulthood • Decrease in both HR & SV • Decreases about 1% per year • Arterial stiffening & elasticity loss which increases SBP • Increases heart’s workload (afterload) • Overall circulation decreases with aging

46. Exercise and Cardiovascular Aging • Exercise can minimize loss in stroke volume • Heart rate changes are less responsive • Exercise can help maintain & minimize loss in aerobic capacity • Exercise can also reduce blood pressure & improve circulation

47. Pulmonary Changes With Aging • Lung compliance increases with aging • Ability for chest to expand decreases • 20% increase in work to breath by age 65 • Vital capacity decreases by 40 to 50% by age 70 • May be due to loss of elastic recoil of lung

48. Pulmonary Changes With Aging • Respiratory changes do not limit exercise capacity • Unless there is severe lung disease

49. Body Composition Changes With Aging • Approximately 1/3 of the population is obese • Childhood obesity is becoming an epidemic • Basal metabolic rate decrease by 5% per decade • Loss of lean muscle mass, atrophy with aging • Loss depends on activity level • Exercise, both aerobic and strength training is the key to minimizing weight gain and muscle atrophy

50. Joint Degeneration With Aging • Progressive loss of flexibility with aging • Loss of collagen fibers • Deterioration of joint soft tissues • Increase in knee and back problems with aging • Significant degeneration of the spine with aging • Excessive weight bearing may play a role • Exercise is great for minimizing rate of joint degeneration & strengthening soft tissues