Improving and maintaining fitness is good for your health. You already know that. In fact, it’s been known for a long time. I can remember my Grandma going to ‘Keep Fit’ classes. But how important is it really?
The short answer: Fitness is very important to your health. In fact, when it comes to extending lifespan (increasing longevity), nothing else comes close.
This is good news. Because your fitness is something you can control. And you only need to reach moderate levels of fitness to get most of the benefits.
It’s probably worth clarifying at this point what we mean by ‘fitness’. The physiological term is ‘cardiorespiratory fitness’ (CRF) and it refers to the ability of your respiratory and circulatory systems to supply oxygen to your muscles during sustained exercise (or any other physical activity).
To understand the impact CRF has on longevity, let’s look at the data from a 2018 study.
122,007 patients (average age 53.4 years) were divided into one of five ‘performance’ groups according to their level of CRF (which was measured using treadmill testing): Low (<25th percentile), Below Average (25th-49th percentile), Above Average (50th-74th percentile), High (75th-97.6th percentile), and Elite (≥97.7th percentile). The patients were then followed for 9 years (on average) and any deaths were recorded.
Now to the results…
Low CRF compared to high CRF was associated with an increased risk in all-cause mortality of 390%. In other words, the probability of dying, at any point in time during the study period, was 3.9 times higher for people with low fitness compared to people with high fitness.
To put this into perspective, the researchers also looked at some of the traditional mortality risk factors. High blood pressure, coronary artery disease, diabetes, and smoking were associated with an increased risk in all-cause mortality of 21%, 29%, 40%, and 41% respectively. Being unfit, therefore, is a much greater threat to your survival than having a serious metabolic disease or being a smoker.
If you’re currently unfit, don’t panic. You don’t have to reach high levels of fitness to significantly reduce your mortality risk. In fact, the biggest reduction in risk is achieved by moving from low fitness (<25th percentile) to above average fitness (50th-74th percentile). Of course, as you might expect, developing high or elite levels of fitness will reduce mortality risk further, but the marginal benefit diminishes as fitness increases beyond ‘above average’.
And how do you go about improving your cardiorespiratory fitness? By doing more aerobic (low to moderate-intensity) and/or anaerobic (high-intensity) exercise. The more you can do the better. But some is better than none.