Quote: “The greatest wealth is health”
- Virgil, Roman poet < 2000 years ago
Higher VO2 Max = Much Lower Risk of Dying…….Get off your ass! Let's illustrate this point:
ICU Patient
68 year old man with diabetes type 2 presenting with weakness and shortness of breath found to have sepsis due to pneumonia. This man is critically ill with sepsis.
His vitals:
Heart Rate 150 (100% of estimated max heart rate: 220 – Age)
Respiratory Rate 54 breaths per minutes
Sweating and looks exhausted.
This man is literally fighting for his life. Can you see why fitness matters so much? How long can he hold on? Many of us will have to fight for our lives in this way at some point. FITNESS REALLY REALLY MATTERS
The Gold Standard for measuring cardiorespiratory fitness = VO2 Max
What is VO2 Max
VO2 Max = the maximum volume of oxygen that can be utilized per kilogram of body weight during maximal exertion
Most often Expressed as:
ml/kg/min (milliliters per kilogram of body weight per minute) [1ml = 1cm3]
This is the gold standard for measuring cardiorespiratory fitness in medicine, exercise science, and research.
Humans range from of VO2 max of 5 (bedbound) to 90s (elite endurance athletes)
Hummingbirds VO2 max = 600 ml/kg/min
Exercise training will improve VO2 Max
So, I hope since listening to part 1 you have gotten “off your ass”
METs (Metabolic Equivalent of Task)
Energy expended by an individual relative to their mass.
Rest is defined as = 1 MET (not moving at all)
(or 3.5 ml/kg/min – this is just a rough estimate for the general population)
So METs * 3.5 = VO2 (in ml/kg/min)
Certain activities have a number of METs associated with them. For example:
Slow walking = 2 METs
Cleaning the house = 3 Mets
Tennis Doubles = 5 METs
Sex = 5.8 METs
Basketball = 8 METs
Jogging 6.8 mile/hr (10.9 km/hr) = 11.2 METs (running a mile in 8 to 9 minutes)
Here is chart of normal METs ranges by age and sex. Multiple the values by 3.5 ml/kg/min to convert to VO2 Max
METs can be a great way to estimate VO2 Max as described below.
Low, medium, high, and elite values for VO2 Max by age group and sex
Table 4
| Performance Group by VO2 Max (ml/kg/min) |
| |||
Age, y | Low | Below Average | Above Average | High | Elite |
Women |
|
|
|
|
|
18-19 | <35 | 35-39 | 40-45 | 45-52 | >52 |
20-29 | <28 | 28-35 | 36-40 | 41-50 | >50 |
30-39 | <27 | 27-33 | 34-38 | 39-48 | >48 |
40-49 | <26 | 26-31 | 32-36 | 37-46 | >46 |
50-59 | <25 | 25-28 | 29-35 | 36-45 | >45 |
60-69 | <21 | 21-24 | 25-29 | 30-38 | >38 |
70-79 | <18 | 18-21 | 22-24 | 25-35 | >35 |
≥80 | <15 | 15-19 | 20-22 | 23-29 | >29 |
Men |
|
|
|
|
|
18-19 | <38 | 38-45 | 46-49 | 50-57 | >57 |
20-29 | <36 | 36-42 | 43-48 | 49-55 | >55 |
30-39 | <35 | 35-39 | 40-45 | 46-52 | >52 |
40-49 | <34 | 34-38 | 39-43 | 44-51 | >51 |
50-59 | <29 | 29-35 | 36-40 | 41-49 | >49 |
60-69 | <25 | 25-29 | 30-35 | 36-45 | >45 |
70-79 | <21 | 21-24 | 25-29 | 30-40 | >41 |
≥80 | <18 | 18-22 | 23-25 | 26-35 | >36 |
Mandsager et al. (2018)
How VO2 max is measured
Gold Standard: Closed breathing circuit that measures oxygen in and CO2 out during max exercise most often on a bike (ergometer) or treadmill. Think an occlusive facemask that covers ones nose and mouth, hooked to a tubing that attaches to a closed loop machine.
Good Approximation: METs x 3.5 = VO2 in ml/kg/min. Most exercise machines show METs. This is a great way to get a rough estimate.
Other Methods: Wearables like watches and rings attempt to measure VO2 max using various algorithms (often proprietary). Many of these are based on things like age, height, weight, heart rate during exercise, and activity data. Resting heart rate, maximal heart rate, and heart rate recovery are often utilized. Sometimes these wearable devices can be surprising accurate at estimating VO2 max. Other times not so much. But they appear to be making steady improvement.
Periodically testing VO2 max using the Gold Standard can be a great way to calibrate these other methods for ongoing VO2 Max testing.
Why increasing VO2 Max makes a person MUCH less likely to die.
- Increasing VO2 Max lowers the risk of dying (mortality risk).
- this risk lowering appears to have no upper limit (inverse, independent, graded)
- being unfit carried a greater risk of death than any cardiac risk factors studied
- this holds true for men, woman, all age groups, and all ethnicities
Let's looks at:
Kokinos et al. 2022 (retrospective cohort study)
- 750,000 Veterans (all demographics, medical problems, statins, smoking, etc. Age 30-95)
- underwent exercise tolerance testing on treadmills (Bruce Protocol)
- 10.2 year median followup
- 175,000 deaths (22.4 deaths per 1000 person years)
- Risk of death for least fit was 4x higher (HR 4.09) than extremely fit individuals
Men and woman > 98th% lived 6 and 6.7 years longer than those in the < 20th percentile!
This study used AI and machine learning to crunch through 750K worth of charts. The revolution in computing is improving research tremendously. More collaboration is needed between scientific researchers and computer scientists than ever before. The Future is bright for research!
I estimate that living a healthier lifestyle can add 10 to 20 years to life (best estimate 12 years). So exercise gets one halfway their! But for healthspan (good years of life) we may be talking 40, 50, even 60 more years…….
Thanks for listening,
Bill Brandenburg, MD
References
- Laukkanen JA, Isiozor NM, Kunutsor SK. Objectively Assessed Cardiorespiratory Fitness and All-Cause Mortality Risk: An Updated Meta-analysis of 37 Cohort Studies Involving 2,258,029 Participants. Mayo Clin Proc. 2022 Jun;97(6):1054-1073. doi: 10.1016/j.mayocp.2022.02.029. Epub 2022 May 11. PMID: 35562197.
- Strasser B, Burtscher M. Survival of the fittest: VO2max, a key predictor of longevity? Front Biosci (Landmark Ed). 2018 Mar 1;23(8):1505-1516. doi: 10.2741/4657. PMID: 29293447.
- Buttar et al. A Review. Maximal Oxygen Uptake (VO2 max) and its Estimation Methods. Int. Journal of Phy Ed, Sports, Health. 2019
- Herdy AH, Ritt LE, Stein R, Araújo CG, Milani M, Meneghelo RS, Ferraz AS, Hossri C, Almeida AE, Fernandes-Silva MM, Serra SM. Cardiopulmonary Exercise Test: Background, Applicability and Interpretation. Arq Bras Cardiol. 2016 Nov;107(5):467-481. doi: 10.5935/abc.20160171. PMID: 27982272; PMCID: PMC5137392.
- Kokkinos P, Faselis C, Samuel IBH, Pittaras A, Doumas M, Murphy R, Heimall MS, Sui X, Zhang J, Myers J. Cardiorespiratory Fitness and Mortality Risk Across the Spectra of Age, Race, and Sex. J Am Coll Cardiol. 2022 Aug 9;80(6):598-609. doi: 10.1016/j.jacc.2022.05.031. PMID: 35926933.
- Wehrlin JP, Hallén J. Linear decrease in .VO2max and performance with increasing altitude in endurance athletes. Eur J Appl Physiol. 2006 Mar;96(4):404-12. doi: 10.1007/s00421-005-0081-9. Epub 2005 Nov 26. PMID: 16311764.
- Suarez RK. Oxygen and the upper limits to animal design and performance. J Exp Biol. 1998 Apr;201(Pt 8):1065-72. doi: 10.1242/jeb.201.8.1065. PMID: 9510520.
- Wikipedia: VO2 Max. Available at: https://en.wikipedia.org/wiki/VO2_max
- Wikipedia: Metabolic Equivalent of Task. Available at: https://en.wikipedia.org/wiki/Metabolic_equivalent_of_task
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