Too much exercise can cause heart disease?

Is there a point where fitness levels rise, but health actually declines?
A 2017 study in Circulation showed the prevalence of subclinical coronary artery disease in masters endurance athletes in the absence of traditional cardiovascular risk factors.
One reason for this is because the excess stress they place on their body, including the excess cortisol production through overexertion. So, prolonged exercise like long-distance runners and cyclists can have an increased risk of heart disease. This can be compounded if the heavy exerciser has poor nutrition.