1. PHTA 2473 Therapeutic Exercise II AHS 2213 Athletic Training Practicum III Chapter 6 Endurance

2. Aerobic Fitness Ability to do work Expressed as… –Aerobic capacity –or- –CV endurance –or- –CV fitness –or- –Cardio respiratory fitness Long duration, low-intensity exercise enhance aerobic fitness

3. Endurance Activities Activities that affect CV system Activities that affect muscular system Examples?

4. VO 2 Max (maximal oxygen uptake) Maximum volume of oxygen consumed during exercise –Measure of efficiency of the aerobic system

5. Aerobic Activity Uses metabolic pathways that use oxygen to provide energy for muscle contraction Aerobic metabolism takes place in the Mitochondria –Oxidative capacity Forms ATP (adenosine triphosphate) –“oxidative phosphorylation” 19x more ATP produced this way than by anaerobic adenosine triphosphate-phosphocreatine (ATP-PC) system.

6. Long term aerobic training can improve aerobic fitness approx. 10%-20% See Box 6-1 p. 100 Shankman

7. Adaptive Physiologic Changes With Aerobic Exercise Notable changes in oxygen transport system –Increased size and # of mitochondria –Increased myoglobin content –Improved mobilization/use of fat and carbs. –Selective hypertrophy of Type I slow-twitch fibers –Decreased resting HR and submax HR –Increased blood volume and hemoglobin –Reduced BP –Improved oxygen extraction rates from blood

8. Measuring and Prescribing Aerobic Exercise Age-adjusted maximum heart rate (AAMHR) –ACSM minimal training intensity for improved VO2 max 60% MHR 220-age=MHR (220-age)(60% to 90%)=THR Karvonen formula –50%-85% VO2 max –Maximum heart rate reserve (MHR reserve) Difference between MHR and RHR MHR-RHR=MHR reserve –How to figure: MHR = 220-age Take RHR Choose intensity level between 50%-85% of VO2 max –(MHR reserve)(intensity level) RHR + Intensity level= Maximum training heart rate Or

9. Karvonen Formula

10. Borg Scale of Relative Perceived Exertion Subjective estimate of exercise Patient reported Relative exertion scale Patients perception of exercise Example: 1 st person: Walking up hill-13 2 nd person: Running up hill-13

11. Borg Scale –6 –7 very, very light –8 –9 very light –10 –11 –12 –13 somewhat hard –14 –15 hard –16 –17 very hard –18 –19 very, very hard Endurance Training Zone Strength Training Zone http://www.medicinenet.com/

12. Frequency, Intensity, Duration ACSM recommendations: –Frequency 3-5 days/week –Intensity 60-90% age adjusted MHR –or- 50-85% MHR reserve –Duration 20-60 minutes continuous aerobic activity

13. Mode of Activity ACSM recommendations –Activity that uses: Large muscle groups Can be maintained continuously Rhythmic Aerobic Examples –Walking –Biking –Jogging –Stair climbing –Rowing –Swimming

14. Mode of Activity Initiation/Intensification of aerobic conditioning program –Higher CV risk –Increased rate of orthopedic injury –Decreased compliance with program

15. Methods of Aerobic Training (2 types) Continuous Aerobic Activities –No rest interval –Little variation in HR –Examples Jogging Walking Running Cycling Stair climbing –What to use in clinic? –Which would burn more calories and use more oxygen: Treadmill or Stationary Bike? Why?

16. Methods of Aerobic Training (2 types)-cont. Discontinuous Aerobic Activities –AKA Interval training –Can involve same activities as continuous –Rest intervals interspersed with bouts of exercise –Advantages Large amounts of high-intensity work in short amount of time –Tends to develop strength and power vs. endurance –Ratio of work to rest 1:1 or 1:1.5 Rest can be passive or active –Which would stress aerobic pathways? –Which would minimize capacity to develop strength and power?

17. Orthopedic Considerations for Aerobic Conditioning Can be challenging Choose appropriate activity for each condition: –Post surgical R/C –HNP –Grade III ankle sprain –ORIF hip fracture –Post op ACL repair

18. Muscle Fatigue (2 hypotheses) Attempt to clarify peripheral neuromuscular fatigue as a result of prolonged or strenuous muscle activity 1 st –Decreasing amounts of energy supplies ATP Glycogen Phosphocreatine 2 nd –Noxious metabolites accumulate Hydrogen ions Ammonia Probably combination of both

19. Circuit Training Combination of resistance (strength) and aerobic exercise Goals –Improve local muscular endurance –Improve cardio respiratory fitness –Improve muscular strength Can customize for desired outcomes 12-15 exercise stations –Various levels of resistance 40-50% of predetermined 1 RM 2 types –Fixed loaded Load or resistance remains constant Improvement occurs when circuit is completed in less time –Target Time required to complete remains the same Complete as many reps as possible in prescribed time 2 ways to perform –15-20 second bouts-no rest –30 second bouts-15 second rest in between

20. Combining Endurance and Strength Goal –Improve strength Strength training combined with moderate, long duration endurance program Goal –Improve endurance Strength and high intensity interval training SAID principle