Maintaining a high level of cardiorespiratory fitness (CRF) is strongly protective against sudden cardiac death (SCD). The Aerobics Center Longitudinal Study (ACLS) run by the Cooper Institute in Dallas, TX is one of the most important and meaningful data sets ever assembled on the power of fitness.

This study followed a group of over 55,000 men and women for nearly 30 years and relied up actual clinical measurements, including treadmill testing and other measures of risk, such blood pressure. This is in sharp contrast to the garbage science the emerges routinely from the health industry, in which there is no measurement (the “researchers” rely upon recall surveys because doing real measurements is hard; poor babies) and no follow-up that matters, but proclamations of great success all around. There should be little doubt in anyone’s mind why people misunderstand and mistrust the scientific community.

What do you take away from this? Maintaining a high level of CRF dramatically reduces the risk of SCD no matter whether or not you have other health conditions. The impact is greatest in people who are unhealthy or overweight. Greater CRF reduced the risk of SCD by 58% to 70%. Stated another way, if you are overweight, but maintain your ability to walk at around 4 mph or do some light jogging, your risk of SCD is 70% lower than a person with the same ailment as you but who cannot walk that fast or jog. Since risk can never be reduced to zero (the most important risk factor for dying of heart disease [assuming no hereditary defect] is age, and you cannot change that.

How you build your CRF doesn’t really matter: walk, swim, jog, run, cycle, circuit train, do kettlebells…do it smartly, with a plan, and get coaching to ensure that you are doing things safely and effectively. Yes, it is true that in the long run, we are all dead, but that’s such a dismal view. Aim to stick around for a while and get the most you can out of life. Your best tool for doing that is — and has been for some time — CRF.

The risk of SCD in US men and women could be partially reduced by ensuring moderate to high levels of CRF independently of other risk factors and especially in those who are hypertensive, overweight, or unhealthy.

Source: Cardiorespiratory Fitness and Risk of Sudden Cardiac Death in Men and Women in the United States – Mayo Clinic Proceedings