Keep Your Body in Motion, Avoid Corrosion
- Dr. Koren
- Mar 7
- 6 min read
How do you envision your golden years? Do your dreams include briskly walking to the airport gate for a flight, exploring the hills of Rome or San Francisco, dancing the waltz or rock-n-roll, or simply playing with your grandchildren, carrying laundry upstairs, or raking leaves? To achieve these goals, your heart, lungs, blood vessels, and muscles must be capable of performing a certain level of work.
How much work, exactly? The energy required for various tasks is measured in METs (metabolic equivalents of task). While sitting quietly, your body consumes approximately 3.5 milliliters of oxygen per kilogram of body weight per minute (ml O2/kg/min), which is equivalent to 1 MET. Brisk walking to catch a plane requires 3-4 METs (more with heavy luggage), raking leaves demands 4 METs, slow waltzing requires 5 METs, and dancing the swing approximately 7 METs.
If you aspire to dance the swing in your 80s, besides knowing the best moves, your body should be able to receive more than 25 ml of O2/kg/min (about 3.5 milliliters of oxygen per kilogram of body weight per minute times 7 METs). The amount of oxygen that your body is capable of extracting under maximum effort is known as VO2 max. VO2 max depends primarily on how much blood your heart is able to squeeze with each beat, how good your blood vessels are at delivering this blood to the muscles, and how efficient your muscle mitochondria are at burning fuel and producing energy. If your desired activity requires 30 ml O2/kg/min, but your body can only provide half that amount, you might manage golf, but swing dancing would be difficult.
For context, the average VO2 max for a healthy 40-year-old man is about 36 ml/kg/min, and for a woman, 27 ml/kg/min, although precise numbers vary depending on the source of reference and the way VO2 max was measured. By the seventh decade, these values drop to 21 ml/kg/min for men and 17.5 ml/kg/min for women.
Estimating Your VO2 Max and Why It Matters
Accurate VO2 max measurement requires specialized equipment. However, you can estimate your VO2 max using the Rockport Walking Test, the Cooper 12-minute run/walk, or the Cooper 1.5-mile run test. Learn more at https://www.whyiexercise.com/VO2-Max.html. Some smartwatches also offer VO2 max estimations, though their accuracy is limited; they are most useful for tracking changes over time.
Sustaining activity at your absolute VO2 max level is only possible for brief, intense bursts. To gauge your body's capacity for more prolonged exertion, a practical approach is to take 80-90% of your VO2 max and then divide that result by 3.5. This calculation yields an estimate of the highest MET level you can realistically maintain over extended periods. For reference, the Compendium of Physical Activities provides comprehensive lists of various activities and their corresponding MET values. For younger adults, consult https://pacompendium.com/adult-compendium/, and for adults aged 60 and older, refer to https://pacompendium.com/older-adult-compendium/. These resources allow you to match your calculated sustainable MET level with activities you enjoy, providing a personalized understanding of your fitness capabilities. Performing activities exceeding your VO2 max would be exhausting or impossible.
What happens with VO2 max as we age
The truth is that whether you are an elite athlete or a couch potato, your VO2 max will decrease with age. However, your VO2 max starting point matters. An elite athlete's VO2 decline from 80 to 30 ml/kg/min still allows for robust daily activity. However, a 55-year-old with a VO2 max of 24 ml/kg/min may face significant limitations while getting older. On the bright side, VO2 max can be improved with exercise starting at any age and a fit 70-year-old can surpass an unfit 20-year-old on a mountain trail.
Regular Physical Activity and Cardiovascular Health
In the previous blog posts (https://www.doctorkoren.com/blog/tags/heart), we were discussing how to reduce the risk of dying from the diseases of heart and blood vessels, the killer #1. Regular physical activity is one of the most effective ways to improve cardiovascular health and increase longevity. Studies show that higher levels of physical activity are associated with a lower risk of cardiovascular disease, reduced likelihood of heart attack and stroke, and lower mortality from all causes. While some data may be influenced by reverse causality (healthier individuals tend to exercise more), even modest increases in activity yield significant benefits, potentially reducing premature death risk by 30%.
Exercise strengthens the heart muscle, improves circulation, and enhances the body's ability to deliver oxygen to working muscles. It also reduces blood pressure, improves cholesterol levels, and lowers the risk of developing type 2 diabetes. By regularly challenging the cardiovascular system through heart-pumping exercise, individuals can increase their VO2 max, delaying the natural decline in endurance capacity associated with aging.
Practical Steps for Starting an Exercise Routine
If you are new to exercise or looking to build a sustainable routine, follow these practical steps:
Assess Your Baseline: It is helpful to know where you are starting. To measure your aerobic and muscular fitness, flexibility, and body composition, write down:
your pulse rate before and right after walking 1 mile (1.6 kilometers)
how long it takes to walk 1 mile or run 1.5 miles (2.41 kilometers).
how many push-ups and squats you can do at a time
how well you move through the full range of motion in your joints
your waist circumference, just above the hipbones at about the level of the bellybutton
Set Goals and Start Gradually: Think about your fitness goals. Setting specific targets can help you monitor your progress and stay motivated. Begin with light activities like walking, stretching, or gentle cycling before moving on to more intense exercises. Find some activity that you enjoy doing. If you have an injury or medical conditions, consult a healthcare or fitness professional. They can assist you in developing a fitness plan that steadily and consistently improves your range of motion, strength, and endurance.
Monitor intensity of your activity: Use the rate of perceived exertion scale.
score 1 is very light activity, hardly any exertion but more than sitting watching TV
score 2-3 - very light activity, can maintain for hours, easy to breathe and carry conversation
score 4-6 - moderate activity, breaking a light sweat, still somewhat comfortable, can speak in short phrases but can't sing
score 7-8 - vigorous activity, borderline uncomfortable, short of breath, can speak a sentence
score 9 - very hard activity, hard to maintain at this level, can barely breathe, don't want to talk
score 10 - maximum effort, feel almost impossible to keep going, completely out of breath, unable to talk, can maintain only for a very short time.
Progress and Consistency: As your fitness improves, slowly increase the duration of your activity by 10% or less each week. Work your way up to 30 to 60 minutes of exercise most days of the week. Aim for at least 150 minutes of moderate-intensity exercise per week or 75 minutes of vigorous-intensity exercise, as recommended by health organizations. When you rate your exertion level as 4-6 out of 10, you are working out at a moderate intensity, and when you rate it as 7-8, you are exercising vigorously.
Incorporate Strength Training: Engage in strength-building exercises at least twice a week to maintain muscle mass and prevent age-related decline in muscle strength and bone density.
Make It a Habit: Finding time for exercise can be difficult. Schedule it like any other appointment. Plan to watch your favorite show while on the treadmill, read while using a stationary bike, or take a break to walk at work. You don't have to complete all your exercise at once; shorter sessions done several times a day are still beneficial. Any activity is better than none. Just as brushing your teeth is a non-negotiable part of your daily routine, exercise should be treated as an essential aspect of personal hygiene and self-care.
Exercise: A Lifelong Investment in Your Health
Your ability to perform activities of daily living and enjoy your golden years depends on your physical fitness today. Regular exercise preserves cardiovascular health, strength, and mobility. Make movement a daily habit, and your future self will thank you for it.
If you'd like to discuss your personal situation and receive individualized advice, schedule an appointment with the Institute for Diabetes, Endocrinology, Adiposity, and Longevity today.
Till next time,
Dr. Koren
References:
Kaminsky, Leonard A. et al. Updated Reference Standards for Cardiorespiratory Fitness Measured with Cardiopulmonary Exercise Testing.
Mayo Clinic Proceedings, Volume 97, Issue 2, 285 - 293
Herrmann SD, Willis EA, Ainsworth BE, Barreira TV, Hastert M, Kracht CL, Schuna JM Jr, Cai Z, Quan M, Tudor-Locke C, Whitt-Glover MC, Jacobs DR Jr. 2024 Adult Compendium of Physical Activities: A third update of the energy costs of human activities. J Sport Health Sci. 2024 Jan;13(1):6-12.
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