Optimizing Exercise for Health and Longevity

The Significant Benefits of Physical Activity

Exercise has been shown in numerous studies to provide substantial reductions in mortality risk across a wide range of chronic diseases, including cardiovascular disease, cancer, diabetes, and Alzheimer’s. The mechanisms behind these risk reductions relate to improvements in lipid profiles, reductions in inflammatory markers, enhanced insulin sensitivity, and more.

Because the health and longevity benefits of exercise are supported by such a large body of evidence, it can be considered one of the most reliable interventions we currently have for extending both lifespan and healthspan. Exercise sits in a Goldilocks zone where too much can be problematic, but too little leads to losing out on these advantages.

Using METs to Quantify Exercise Dose

To better understand optimal exercise ranges, exercise scientists rely on the concept of metabolic equivalents, or METs. One MET represents the energy cost of sitting at rest, which provides a baseline measurement. Activities like walking slowly or mowing the lawn might require 3-5 METs. More intense exercise like jogging, cycling, or resistance training can require 6-14 METs depending on the pace and duration.

By tracking the intensity level in METs alongside the duration of activities, we arrive at an overall dose measurement called MET-hours. For example, jogging for one hour at a pace requiring 10 METs leads to 10 MET-hours. Comparing MET-hours allows us to compare health outcomes across different forms of exercise more accurately.

The Potential Risks of Excessive Exercise

Current exercise recommendations related to longevity aim to identify the Goldilocks zone where exercise provides optimal benefits without going into excessive levels that could increase health risks. The hypothetical point where risks might start to rise is known as the “J-curve” based on the shape it would create on a dose-response graph.

Evidence for the upper J-curve threshold is limited, but could provide insight into the underlying mechanisms of how exercise impacts the body and disease progression. Most people do not need to be concerned with excessive exercise levels, but athletes and others performing very high volumes of intense training should be aware it remains an open question.

Takeaways for Optimizing Your Exercise Regimen

 
• The health gains from exercise are well-supported for a variety of chronic diseases
• Quantifying exercise by intensity (METs) and duration (hours) provides a standardized dose measurement (MET-hours)
• Research is still examining if extremely high exercise doses could lose benefits or increase risks
• Use exercise tracking by MET-hours to help optimize your regimen based on current evidence