Is cardiovascular fitness the best marker for longevity?
- Dr. Kenji Kaye, MD
- Jul 23
- 3 min read
Many of my patients ask about what their focus should be when it comes to preparing their body and health for the long-haul. We can have a whole discussion on what longevity means but for now we will focus on the best marker for long term mortality risk---cardiorespiratory fitness (CRF).
Cardiorespiratory fitness can be quantified in many different ways including VO2 max and Metabolic Equivalent of Task (MET). One MET is defined as the amount of oxygen consumed while sitting at rest and is equal to 3.5ml O2 per kilogram body weight x min.1 METs are used to compare the intensity of activities and is a relative measure derived from oxygen uptake during an activity compared to rest. VO2 max is defined as maximal oxygen uptake attained during maximal exercise intensity. Typically, VO2 max is measured as ml/kg/minute. 2 VO2 max can be directly measured exercising on a treadmill or a bike wearing a metabolic mask at an intensity that progressively increases until exhaustion. MET is a standardized scale to compare activity intensity, while VO2 max is a personal maximum oxygen uptake capacity. For example
For simplicity’s sake we can think of METs like gasoline consumption for a car. At idle, your car is not consuming that much gas but at higher speeds or with heavy towing the gasoline consumption of the engine increases. However unlike gasoline consumption that can be directly measured, METs are a standardized measurement. In clinical practice we usually ask questions about a patient's activity. For example, "Are you able to go to the grocery store, shop around, push the cart around, and load the groceries in and out of your car?" if the answer is yes then we can infer that the patient is able to achieve around 3 METs.
1 MET is equivalent to sitting watching TV or reading.
1-3 METs is for light activities like walking or light household chores
3-6 METs include activities like a brisk walk, slow cycling or gardening
6-10 METs is vigorous activity like jogging, weight lifting, fast cycling
>10 METs is usually considered extremely vigorous for activity like competitive swimming, running, etc.
How does cardiorespiratory fitness correlate with longevity?
According to a 2018 article published in JAMA that examined 120,000 patients in a retrospective cohort study cardiorespiratory fitness was inversely proportional to long-term mortality. This means that the better the “cardio” some one has the less chance of dying from all causes. The most benefit (reduction in risk) was seen in older patients with hypertension.3
Additionally, it was interesting that the study also suggested that a low cardiorespiratory fitness level was worse for your long-term mortality than just having coronary artery disease, smoking or diabetes.
Figure 1
What does this mean for me?
While it is not overly shocking that this study showed that the better your cardiovascular fitness is the longer your life expectancy. However it is good reinforcement that we should prioritize a strong foundation of cardiovascular fitness into our health plan as early as possible. I like to start with a foundation of Zone 2 cardio and progressively adding on higher intensity workouts.
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