That is an interesting study and thanks for the link.
A couple of important take aways from the article and then some comments on calcium scores.
From the article:
"Exercise and physical activity reduce the risk of cardiovascular disease (CVD). It has been observed that an active individual is at a 30% to 40% lower risk of CVD."
"No correlation was found between exercise volume and the progression of coronary atherosclerosis during the follow-up."
Exercise has been proven better than any medication at lowering the risk of heart disease and all cause mortality, so by all means do not stop exercising out of concern that it will increase your calcium score. For one thing, correlation does not mean causation.
Calcium scores are often misunderstood. The calcifified plaque is the stabilized plaque in our arteries- sometimes referred to as hard plaque. The real danger is soft plaque which has not yet been stabilized and at risk of bursting and causing a clot.
Let's say that a 48 year old, with no baseline CAC gets gets a CAC completed and scores 900. That is very bad and would indicate that the person is at high risk. But, the risk is more due to the fact that where there is smoke there is often fire. This person would almost always have a heavy soft plaque burden as well, which is the type of plaque putting him at risk of cardio vascular events, more so than the calcified plaque. Soft plaque and calcified plaque usually go hand in hand, but not always and it depends if the individual has been on treatment to stabilize his soft plaque, such as statins, or other factors which could have led to stabilization of soft plaque, such as improved lifestyle choices.
In addition to lowering LDL, statins also stabilize soft plaques. This is one of the reasons why they significantly lower the risk of heart attacks and strokes. For example, someone I know had a heart attack in his 40s. His CAC score came back at about 100. He was put on a number of medications, including PCSK9-inhibitor and statins. The next year his CAC score went up significantly, and he got very upset. It turns out that this occured because the statin was doing its job and stabilizing the soft plaque. His soft plaque burded had decreased considerably becuase it had been calcified and stabilized.
I am not saying that having a high CAC score is good. But, there is more to the story. Generally, a CAC score does correlate with a higher risk for heart events, with increasing score correlating with increase rate of events. But, without knowing more information, it would be impossible to say whether someone at a CAC score of 200 is at greater risk than another person who has a CAC score of 50. Perhaps the person at 200 was at 75 CAC a year earlier, with a heavy soft plaque burden. His cardiologist put him on a statin and now most of the soft plan has been stabilized, and he now shows a 200 score, but imagery reveals that the his soft plaque burden is very low. At the same time, the person who scored a 50 could have a much higher soft plaque burden. Without the advanced scans being completed, it is impossible to know the true risk. All that being said, if a person presents with a very high CAC scan, there is almost certainly heart disease present and there needs to be follow up.
So, I would look at CAC as a marker which could indicate the need for more testing to see what is going on.
Perhaps there is something about doing intense exercise that is causing damage to the endothelium and increasing the plaque burden. On the other hand, perhaps there is something about the intense exercise which is causing the soft plaque to stabilize, leading to a slightly higher CAC score, but a lower CAD risk, due to the stabilization of soft plaques. Without the advanced imagery, which includes the soft plaque burden, it is impossible to say whether these athletes are truly at higher risk. Following hard outcomes, such as actual cardiac events and mortality, is always better than following biomarkers. The hard outcomes have strongly suggested for decades that increasing exercise lowers risk of CAD and mortality.
For those who are interested I'll link below info on CCTA scans, which can dedect not only calcified plaque, but also soft plaque. A friend whose family has genetic dyslipidemia just had himself and his family tested. It cost him $1,400 out of pocket for each test. Not cheap, which is why we will not likely see this done in many large studies unless they are well funded. It's much cheaper to look at markers and not pay for imagery which gives a much clearer risk perspective. Like CAC scans, one downside of CCTA scans is that there is some radiation risk. Probably neither are something that should be done with too much frequency.
CCTA scans:
"CCTA can detect 'soft' non-calcified plaque in patients who have a zero-calcium score"
"The latest European dyslipidemia guidelines have, however, adopted the use of CCTA findings and it is likely that other societies will follow suit. Data presented on the efficacy of statins, PCSK9 inhibitors and IPE to modify plaque risk markers may encourage the adoption of CCTA"
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7914610/#:~:text=CCTA can detect 'soft' non,26] (Table 1).
On a personal note, since my surgery I have modified my type of exercise. I do probably about 95% of my training in zone 2, which would be considered moderate. I do this because several studies have found zone 2 training to be the zone which maximizes mitochondria health and mitochondrial health is one of the most important markers for good health in general and longevity. Once a week I push beyond zone 2 when I do my boxing sparring rounds. Where a person's zone 2 is will depend on their fitness level and their max heart rate. My zone 2 is when my heart rate is between about 105 bpm and 125 bpm.
