Maintaining Cardiovascular Fitness During Rehabilitation

1. Maintaining Cardiovascular Fitness During Rehabilitation

2. Why is it important to maintain cardiorespiratory fitness? It is a critical component of any rehabilitation, but is often the most neglected Considerable amounts of time are spent preparing for the demands of a season Time lost due to injury can result in considerable cardiorespiratory decrements Cardiorespiratory Endurance Ability to perform whole-body activities for extended periods of time without excessive fatigue

3. Training Effects on the Cardiorespiratory System Cardiorespiratory activity is a coordinated function of 4 components to transport O2 throughout body Heart Blood vessels Blood Lungs Improvements due to training Results in ? capability of each of the above elements Provides necessary oxygen (O2) to working tissue

4. Adaptations of the Heart to Exercise Heart Rate (HR) With exercise, the muscle’s use of ? O2 results in an ? need for O2 transport Heart work load increases proportionally to intensity of exercise Monitor HR = indirect measure of ? consumption

5. Stroke Volume (SV) Volume of blood being pumped/beat Approximate volume pumped = 70mL/beat Maximal volume = 40-50% of HRmax 110-120 beats/min. Above this point ? in volume being pumped is related to heart rate ?

6. Cardiac Output (Q) – Amount of blood heart pumps/minute Q = SV x HR Normal = 5L blood/min. @ rest Primary determinant of maximal O2 rate consumption With exercise, Q ? 4x-6x of resting levels (normal – endurance athlete) Training effect Stroke volume ? while exercise heart rate ? Heart efficiency Heart hypertrophy w/ exercise Females 5-10% higher Q than males (likely due to lower concentration of hemoglobin in the female, which is compensated for during exercise by an increased cardiac output

7. Adaptations in Blood Flow Blood flow is modified during exercise Flow to non-essential (exercise related) organs is decreased Results in increased flow to working muscles Even though blood flow to heart increases – the percentage of total cardiac output remains unchanged Increase in blood vessels to musculature Total peripheral resistance decreases during exercise Increase in vasodilation

8. Blood Pressure (BP) Determined by cardiac output in relation to total peripheral resistance to blood flow Systolic pressure - pressure created by heart contraction (top number) Diastolic pressure - relaxation of heart (bottom number) Systolic pressure ? in proportion to O2 consumption & Q Consistent aerobic exercise will produce ? in overall resting BP levels

9. Adaptations in the Blood Training for improved cardiovascular function ? total blood volume As a result of increased blood volume, increased O2 carrying capacity increases Total available hemoglobin increases Overall hemoglobin concentration remains the same or may slightly ? with training Hemoglobin - O2 is transported throughout the system; iron-containing protein that has the capability of easily accepting or giving up molecules of O2 as needed

10. Adaptations of the Lungs Pulmonary function improves with training Volume of inspired air ? Diffusion capacity of lungs ? Enhances exchange of O2 and carbon dioxide Pulmonary resistance to air flow is also ? Overall Effects of Training ? resting heart rate ? heart rate at specific workloads ? recovery time ? muscle glycogen use Unchanged cardiac output ? stroke volume ? capillarization ? lung functional capacity

11. Maximal Aerobic Capacity Maximal oxygen consumption (VO2max) Volume of O2 consumed per body weight per unit of time (ml/min/kg) Best indicator of cardiorespiratory endurance Average college athlete = 50-60 ml/min/kg World class endurance male athlete = 70-80 ml/min/kg World class endurance female athlete = 60-70 ml/min/kg

12. Rate of Oxygen Consumption Rate of O2 consumption is about the same for all individuals, depending on fitness level per activity Greater intensity = greater O2 consumption A person’s ability to perform activity is related to amount of O2 required by that activity Ability is limited by the max. rate of O2 consumption the person is capable of delivering into the lungs Fatigue occurs when: Insufficient O2 supplied to muscle Greater % of maximal O2 consumption during an activity = less time activity can be performed

13. Factors affecting maximal rate External respiration (involving ventilatory process) Gas transport – accomplished by cardiovascular system Internal respiration (use of O2 by cells to produce energy) Most limiting factor is ability to transport O2 through system High maximal aerobic capacity indicates all 3 levels are working well

14. Maximal Aerobic Capacity: Inherited Characteristic Genetically determined range Training allows athlete to obtain highest level within that range Fast-Twitch vs. Slow-Twitch Muscle Fibers Range of VO2max is largely determined by metabolic and functional capability of skeletal muscle Higher % of fatigue resistant, endurance oriented slow-twitch fibers will enable individual to utilize more O2 and have higher VO2max

15. Cardiorespiratory Endurance and Work Ability Cardiorespiratory endurance is key component in individual ability to perform daily activities Fatigue & percent of VO2max are closely related for particular workload (A vs. B) Training goal Increase ability of cardiorespiratory system to supply a sufficient amount of O2 to working muscles

16. Producing Energy for Exercise Cellular Metabolism To Grow, Generate energy, Repair damaged tissue, Eliminate waste Energy is produced from the breakdown of nutrients resulting in formation of Adenosine triphosphate (ATP) (primary energy store) ATP is produced in muscle tissue Glucose from blood or glycogen (muscle or liver) is broken down to glucose & converted to ATP Glucose not needed immediately is stored as glycogen in the resting muscle & liver; can be later converted back Fat and protein can be utilized to produce ATP Fat is utilized when glycogen stores become depleted Activity becomes more duration/endurance oriented Different activities have differing energy needs and rely on different cellular processes

17. Aerobic vs. Anaerobic Metabolism Both systems generate ATP Initial ATP production from glucose occurs in muscle (without O2 = anaerobic) Transition to glucose & fat oxidation (requiring O2 = aerobic) to continue activity Generally both systems occur to a degree simultaneously Type of ATP production relative to intensity Short burst (high intensity) = anaerobic Long duration (sustained intensity) = aerobic

18. Excess Post-exercise Oxygen Consumption (Oxygen Deficit) With ? intensity, insufficient amounts of O2 are available which results in O2 deficit Occurs initially during activity (1st 2-3 min. of exercise) – body adapts Hypothesized that it may be a result of initial lactic acid production Deficit may be the result of disturbance in mitochondrial function due to increased temperature

19. Techniques for Maintaining Cardiorespiratory Endurance Primary concern Nature of injury & techniques available as a result of injury Upper vs. Lower extremity injury & options Match fitness Engagement of functional activities specific to sport to maintain fitness Goal Maintain fitness levels

20. Continuous Training FITT Principle Frequency Intensity Type (mode) Time (duration) Frequency Competitive athlete should be prepared to engage in fitness activity 6 times per week, allowing 1 day for body repair and maintenance

21. Intensity Should be heart rate controlled & monitored Goal is to plateau heart rate at desired level Monitor pulse Preferably radial pulse Should be engaged in workout for 2-3 minutes prior to checking Workouts should be set as percentage of heart rate max (60-90% ACSM recommendation) Appropriate estimate of HRmax = 220-Age Karvonen formula Target HR = HRrest + (0.6[HRmax-HRrest]) Rate of Perceived Exertion (RPE) Scale (6-20) that can be used to rate exertion level during activity

22. Type of Exercise For continuous training activity must be aerobic Easy to regulate intensity (speed up or slow down) Intermittent exercise is too variable (speed and intensity) Time (duration) Minimal improvements = exercise for 20 minutes ACSM recommends 20-60 minutes with HR elevated to training levels Greater duration = greater improvements

23. Interval training Intermittent activities involving periods of intense work & active recovery Must occur at 60-80% of maximal heart rate Allows for higher intensity training at short intervals over an extended period of time Most anaerobic sports require short burst which can be mimicked through interval training HR may reach 85-95% of maximum at peak and 35-45% during rest Should be combined with continuous training

24. Fartlek Training Cross-country running that originated in Sweden Speed play Similar to interval training in the fact activity occurs over a specific period of time but pace and speed are not specified Puts surges into workout, varying length of surges to specific needs Consists of varied terrain which incorporates varying degrees of hills Dynamic form of training – less regimented Must elevate heart rate to minimal levels to be effective Popular form of training in off-season

25. Par Cours Combination of continuous & circuit training Jogging short distances, from station to station, & performing a designated exercise Gain aerobic fitness while performing calisthenics Found typically in recreational parks