There’s a new study out that shows that cardiorespiratory fitness (max effort on a treadmill – like a “stress test”) is associated with decreased risk of death due to cardiovascular disease. The findings are pretty cool and the effects are pretty large. Let’s break it down.
What did they do?
- The researchers enrolled 1,000-4,000 people between the ages of 20 and 90 each year from 1970-2006 who came to their clinic in Texas for a complete clinical visit.
- They excluded anyone who had a heart attack previously, which still resulted in a sample size of 66,371 people, which is pretty solid.
- The researchers collected a bunch of information like blood pressure, cholesterol, smoking status, and fitness. Fitness was assessed with a maximal treadmill exercise test by setting the speed to about 3.3 miles/hour and then increasing the grade by 1% each minute until the person was exhausted (note: I don’t think anyone is arguing that this is the best measure of fitness, but just a straightforward and standardized one).
- Then the researchers followed-up with these people either until they died or up to 36 years (1970-2006). The main outcome measure was death from cardiovascular disease.
What did they find?
Take a look at the figure above. It shows the relative risk of dying from cardiovascular disease associated with the variables on the left. A risk of 1 (dotted line) means no change or no effect of the variable. What you can see from this figure is that the usual suspects like smoking and diabetes increased the risk of death from cardiovascular disease – maybe no surprise here. However, what is most interesting about this study is how the results of the treadmill test (i.e., fitness) predicted decreased risk of death from cardiovascular disease. Those who had the best fitness scores and were in the top 40% (quintiles 4 and 5) for both men and women were approximately three times less likely to die from cardiovascular disease.
The results are impressive. Cardio fitness has a greater impact than smoking. So, what do you say folks? Let’s get (and stay) fit.