VO2 MAX Exercise Physiology Content.pptx

Dr. V. SURESH KUMAR
Professor in Physiotherapy
Mother Theresa Institute of Health Sciences
Govt. of Puducherry Institution

1. VO2 MAX Fitness can be measured by the volume of oxygen consumed while exercising . Done at your maximum capacity . DEFINITION: " the highest rate of oxygen consumption attainable during maximal or exhaustive exercise” “ VO2max is the maximum amount of oxygen – in milliliters – one can consume per kilogram of body weight.

2. VO2 MAX - USES The point at which oxygen consumption plateaus defines the VO2max or an individual's maximal aerobic capacity . It is the best indicator of cardio respiratory endurance and aerobic fitness and upper limit of ATP production via mitochondrial respiration(aerobic metabolism Also known as……… Aerobic power Aerobic capacity Maximal oxygen uptake .

3. VO2 MEASUREMENT One can increase their VO2max by working out at an intensity that raises their heart rate to between 65 % - 85 % of its maximum heart rate. For AT LEAST 20minutes, 3-5times a week. VO2max Values AVERAGE ADULT: 35-40 ml/kg/min ATHLETE : 50-60 ml/kg/min ELITE ATHLETE ; 70-80ml/kg/min VO2max is expressed either as an Absolute rate in e.g. Liters of oxygen per minute(L/min ) OR as a Relative rate in (e.g. milliliters of oxygen per kilogram of body mass per minuets ( ml.kg-1.min- 1)

4. To determine if someone has attained VO2 max during exercise, you can use the following methods and equipment: * Gas Exchange Analysis*: Measures oxygen uptake and carbon dioxide production through a mask or mouthpiece. - Equipment: Metabolic cart or gas analyzer (e.g., Cosmed , ParvoMedics ) 2. * Heart Rate Monitoring*: Tracks heart rate responses to exercise.     - Equipment: Heart rate monitor (e.g., Polar, Garmin), Electrocardiogram (ECG) 3. * Blood Lactate Testing*: Measures lactic acid accumulation in blood.     - Equipment: Lactate analyzer (e.g., Lactate Pro, Accutrend ) 4. * Respiratory Exchange Ratio (RER)*: Measures the ratio of carbon dioxide production to oxygen uptake.     - Equipment: Metabolic cart or gas analyzer 5. * VO2 max Protocol*: Standardized exercise tests, such as the Bruce Treadmill Test or the Åstrand Test.     - Equipment : Treadmill or cycle ergometer

5. VO2 MAX Simple Method Using the Resting and Maximum heart rate you already determined, Individual Maximum Heart Rate is calculated as 220 – AGE you can plug those values into the formula and calculate your VO2 max. Let’s say you’re Resting heart rate is 80 bpm and your Max heart rate is 195 bpm. Write the formula: VO2 max = 15 x ( HRmax / HRrest ) Plug in the values: VO2 max = 15 x (195/80). Solve : VO2 max = 15 x 2.44 = 36.56 mL/kg/min

6. The Bruce Protocol is a standardized treadmill test used to estimate VO2 max. Here's how VO2 max is determined: 1_Treadmill stages _: The test consists of 7 stages, each lasting 3 minutes, with increasing intensity:     - Stage 1: 1.7 mph, 0% incline     - Stage 2: 2.5 mph, 5% incline     - Stage 3: 3.4 mph, 10% incline     - Stage 4: 4.2 mph, 15% incline     - Stage 5: 5.0 mph, 20% incline     - Stage 6: 5.5 mph, 25% incline     - Stage 7: 6.0 mph, 30% incline 2. _Oxygen uptake measurement_: During the test, oxygen uptake (VO2) is measured using a cart or gas analyzer. 3. _VO2 max estimation_: The highest VO2 value achieved during the test is considered the estimated VO2 max. 4. _Time to exhaustion_: The test continues until the subject reaches exhaustion or completes the 7th stage. 5. _VO2 max calculation_: The estimated VO2 max is calculated using the following formula:

7. To calculate VO2 max in the Bruce Protocol: Record the total time (in minutes) completed by the individual during the test. 2. Use the following formula : VO2 max (ml/kg/min) = 4.37 x T + 14.8 Where: T = total time (in minutes) Example : If the individual completes the test in 12.5 minutes: VO2 max (ml/kg/min) = 4.37 x 12.5 + 14.8 = 54.6 + 14.8 = 69.4 ml/kg/min Note: This formula is specific to the Bruce Protocol. - VO2 max values can vary depending on individual factors such as fitness level, age, sex, and weight. - This calculation provides an estimate of VO2 max, which may not reflect the individual's true maximum oxygen uptake.

8. Signs of attaining VO2 max: * Plateau in oxygen uptake*: No further increase in oxygen consumption despite increased exercise intensity. 2. *Maximum heart rate*: Reaching a heart rate within 10-15 beats per minute of predicted maximum. 3. *High blood lactate levels*: Accumulation of lactic acid in the blood, indicating anaerobic metabolism. 4. *RER ≥ 1.15*: Indicates high-intensity exercise and potential attainment of VO2 max. Remember, a trained professional should supervise and interpret these tests to ensure accurate and safe assessmen

9. VO2 MAX Highest recorded VO2max 94 ml/kg/min in men 77 ml/kg/min in women Both were cross-country skiers .

10. Training Effects Regular aerobic training raises V02 Max ………. Due to: Increased cardiac output and stroke volume Increased haemoglobin Increased glycogen stores Increased OBLA (more on that in a minute ) (Onset of Blood Lactate Accumulation) Reduced body fat (therefore less oxygen being used for the energy systems ) Why do these effects occur with aerobic training ? • You’re forcing the body to either find more oxygen, or create ways of getting the oxygen from the lungs to the working muscle .

11. Oxygen Debt OR RECOVERY STAGE OR "Excess Post-exercise Oxygen Consumption" (EPOC )) Definition : Extra amount of oxygen, that must be supplied to body after exercise , in order to restore metabolic system back to pre-exercise State . OR The additional oxygen that must be taken into the body after vigorous exercise to restore all systems to their normal states is called oxygen debt

12. OXYGEN CONSUPTION During exercise oxygen consumption is increased by skeletal muscle. Oxygen is present: 1. In combination with Hb , In myoglobin & In dissolved form Oxygen used in severe exercise : 0.3 L O2 combined with Myoglobin 1 L O2 combined with Hemoglobin 0.5 L O2 in alveolar air 0.25 L dissolved form TOTAL OXYGEN = 2 L (approx .) 2. To restore phosphagen & glycogen system: 2 L is required . 3 . To restore Aerobic system: 8 L is required. So , a total of 10 – 12 L oxygen is used in exercise & is paid in 90 min after exercise Respiratory rate remain increased for 90 min after exercise to repay oxygen debt = 10 – 12 L This much oxygen must be repaid

13. WHY NEED OF RECOVERY….? When you exercise intensely, your body uses anaerobic energy systems , which don't require oxygen. However , this leads to a buildup of lactic acid and other metabolic byproducts. After exercise, your body needs to: 1 . Replenish energy stores 2. Remove lactic acid and other waste products 3. Reestablish normal cellular function To do this, your body requires additional oxygen, which is the O2 debt. Your body pays back this debt by increasing oxygen consumption after exercise, which can take several minutes to several hours . Paying Back Benefits: 1. Improved cardiovascular function 2. Enhanced Metabolic function 3. Increased Fat oxidation

14. DEBT. RECOVERY In low-intensity, Primarily aerobic exercise, about one half of the total EPOC occurs within 30 seconds of stopping the exercise. Complete recovery can be achieved within several minutes (oxygen uptake returns to the pre-exercise level). Recovery from more strenuous exercise , often accompanied by an increase in blood lactate and body temperature, may require 24 hours or more before re-establishing the pre-exercise oxygen uptake. The amount of time will depend on exercise intensity and duration

15. OBLA (Onset of Blood Lactate Accumulation) This means The point at which the muscle can no longer get rid of the lactic acid and it begins to pool in the blood Normal amount of lactate in the blood : 1 ml/kg OBLA occurs at : 4 ml/kg Once the blood contains four times as much lactic acid as normal

16. OBLA and Vo2MAX Average person reaches OBLA at 40 % of Vo2MAX Meaning that the average person can only work at less than half their maximum ability before fatigue sets in . Endurance athlete reaches OBLA at 85 % of Vo2MAX The endurance trained athlete can work at almost maximum before fatigue set in.

17. Factors Affecting OBLA Intensity of exercise – compare short burst,high intensity to long distance, steady state . Muscle fibre type being used – more on that later. The ability of the body to remove and oxidise lactate. Training adaptations to exercise

18. Effects of OBLA Stops oxygen being collected by the haemoglobin Causes the pH of the blood to rise causing pain in the working muscle Also decreases the amount of oxygen that can be used for phosphorylation. Will eventually lead to the muscle failing – you collapse!

19. FITNESS FOR NORMAL PERSON - Moderate Moderate-intensity walking (about 5-6 km/h ): - Aim for at least 30 minutes per session, 5 days a week, which translates to approximately 7-10 kilometers per week. - To increase fitness, aim for 45-60 minutes per session, 5 days a week, which is around 10-15 kilometers per week . Brisk walking (about 6-7 km/h ): - Aim for at least 30 minutes per session, 5 days a week, which translates to approximately 10-12 kilometers per week. - To increase fitness, aim for 45-60 minutes per session, 5 days a week, which is around 15-20 kilometers per week.

20. FITNESS TEST FOR NORMAL PERSON T here are several physical fitness tests that can help assess your basic fitness level for routine life. Here are a few examples: 1. * 1-Mile Walk Test*: Walk 1 mile at a moderate pace. If you complete it in: - Under 15 minutes, you're fit. - 15-17 minutes, you're average. - Over 17 minutes, you may need improvement. 2. *Step Test*: Climb 12 steps at a moderate pace. If you: - Recover in under 90 seconds, you're fit. - Take 90-120 seconds, you're average. - Take over 120 seconds, you may need improvement. 3. *Sit-to-Stand Test*: Stand up from a seated position without using your hands. If you can: - Stand up 10+ times in 30 seconds, you're fit. - Stand up 5-9 times, you're average. - Stand up fewer than 5 times, you may need improvement. 4. *Body Mass Index (BMI)*: Calculate your BMI using your weight and height. Aim for a BMI between 18.5 and 24.9. 5. *Waist Circumference*: Measure your natural waistline. For men, aim for under 40 inches (102 cm). For women, aim for under 35 inches (88 cm)

21. TRAINING PROCEDURE Warm-up Whole body exercise to raise heart rate and body temperature. Stretching to prepare muscles, ligaments and joints. Practising skills and techniques to be used in the session. 2. Main activity - this could be: Fitness training - which may be linked to repeated technique work. Skill development - drills or team practices. Modified or Conditioned Games. 3. Warm down (sometimes called cool down) Light exercise to help remove carbon dioxide, lactic acid and other waste products. Gentle stretching to prevent muscle soreness and stiffness later.

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23. OBLA• Stands for…….?• Onset of BloodLactateAccumulation • And this means…..?• The point at whichthe muscle can nolonger get rid of thelactic acid and itbegins to pool in theblood 11. OBLA• Normal amount of lactate in the blood:• 1 ml/kg• OBLA occurs at:• 4 ml/kg• Once the blood contains four times asmuch lactic acid as normal, it can nolonger operate the energy systemseffectively and the body begins to slowand eventually fail. 12. 13 . OBLA• The affects of OBLA:• Stops oxygen being collected by thehaemoglobin • Causes the pH of the blood to risecausing pain in the working muscle• Also decreases the amount of oxygenthat can be used for phosphorylation.• Will eventually lead to the musclefailing – you collapse! 14. OBLA• If the intensity of the activity increases,the performer will have to switch fromusing aerobic capability to anaerobic,which results in…….?• Increased lactate build up. 15.

24. VO2 Mearsurement Direct testing Requires sophisticated equipments to measure the volume and gas concentration Indirect   testing Does not required any specific equipments . Treadmills, cycle ergo meters and other exercise equipments are used to measure VO2max Bruce Protocol is often used for testing VO2max in athletes or for signs of coronary heart disease. Multistage shuttle run , 12 minutes walk test ,1.5 mile run tests are used.

25. Gender-specific equation. This particular test has two different equations : One for men and one for women . Women : 100.5 - (0.1636 x weight in kg) - (1.438 x jog time) - (0.1928 x heart rate) Men : 108.844 - (0.1636 x weight in kg) - (1.438 x jog time) - (0.1928 x heart rate)

26. VO2 max using Equation : VO2 = 132.853 – (0.0769 x weight in lb ) - (0.3877 x age) + (6.315 x gender) - (3.2649 x walk time in minutes) - (0.156 x heart rate). If you are male, use the number 1, if you are female, use the number 0 for the calculation . For example: A 26 year-old male who weighs 160 lbs , walks a mile in 15 minutes and has a heart rate of 120 at the end. VO2 = 132.853 – (0.0769 x weight in lb ) - (0.3877 x age) + (6.315 x gender) - (3.2649 x walk time in minutes) - (0.156 x heart rate) VO2 = 132.853 – (0.0769 x 160) - (0.3877 x 26) + (6.315 x 1) - (3.2649 x 15) - (0.156 x 120) VO2 = 132.853 - 12.304 – 10.08 + 6.315 – 48.97 – 18.72 = 49 mL/kg/min