IJCS | Volume 32, Nº4, July/August 2019

320 Araújo et al. Exercise/sport & cardiovascular Health: an update Int J Cardiovasc Sci. 2019;32(4):319-325 Viewpoint with a ~15% reduction in mortality in patients with and without cardiovascular disease. Indeed, a recent landmark study reported that the most physically active cohorts of men and women demonstrated 7- to 8-year gains in life expectancy. 2 Increased levels of habitual PA prior to hospitalization for acute coronary syndromes are also associated with better short-term cardiovascular outcomes. In contrast, individuals with low CRF have higher annual health care costs, higher rates of surgical complications, and are more likely to die prematurely than their matched counterparts. Although arterial dysfunction has been widely considered a marker of age-associated cardiovascular disease, regular aerobic exercise inhibits large artery stiffening and preserves endothelial function. Increased CRF in middle-age is also associated with a lower risk of developing heart failure, regardless of the body mass index. 3 Vigorous PA (≥ 6 METs) appears to be superior to moderate-intensity exercise (3.0 to 5.9 METs) in promoting health benefits. However, patients should be counseled to augment their CRF by starting with level walking at a 2.4 to 4.8 km/h pace and gradually progress tomore vigorous exercise, provided they remain asymptomatic. Aerobic exercise should be complemented with flexibility and resistance training. Although some studies suggest that high intensity interval training (HIIT) elicits greater increases in CRF than moderate intensity training, concerns regarding the safety of HIIT in “at risk” patients suggest that it should be cautiously prescribed. 4 Vigorous PAappears to be superior tomoderate-intensity exercise in promoting health benefits. Cardiorespiratory fitness (CRF) as a prognostic marker for sudden cardiac death and all-cause mortality Jari Laukkanen Q: It is already known that high levels of CRF are related to longer life expectancy. On the other hand, sudden cardiac death, always a very dramatic event, is a rare event that is often difficult to be prevented. What do you currently know about the possible influence of a high CRF on the incidence of sudden cardiac death and if there is such influence, what are the most probable mechanisms involved? A: Sudden cardiac death (SCD) is a devastating event which has a profound effect on the families affected, and it is an ongoing challenge for physicians, healthcare providers and global economies. Previous evidence supports the concept that modulation of risk factors would provide pivotal ways of preventing SCD in the general population. 5 However, measurements of functional capacity, such as CRF, are correlated with risk for SCD. CRF has been suggested as a strong predictor of SCD in the population and considered a vital marker in patient risk assessment. 6 Our study group has recently found early evidence on the association between good CRF and lowered risk of serious ventricular arrhythmias. 7 We have also found that a good CRF may attenuate the risk of SCD in overweight/obese men, suggesting that a good CRF may reduce the risk of SCD in high risk subjects. 8 In our prospective population study, 5 VO 2peak yielded only a modest improvement in SCD risk prediction, and there was a slight improvement in the level of discrimination on the top of cardiovascular risk factors and other confounders. However, further evidence is needed to know to which extent the incremental prognostic information offered by the assessment of CRF aids in risk stratification and prevention of SCD. Changing from low to high CRF improves clinical prognosis Jari Laukkanen Q: An adult with high levels of cardiorespiratory (aerobic) fitness tends to live longer and better. CRF is known to depend on both genetic traits and regular exercise pattern. Unfortunately, most of subjects in the world are either sedentary or have insufficient exercise to keep or to get high CRF levels. So, from a practical viewpoint, is it always time to try to adopt an exercise plan to improve CRF levels or is there an age limit for this? If a previously sedentary patient gets to improve the CRF with exercise training, will this have a positive effect on his/her long-term clinical outcomes? A: Almost all previously sedentary patients are able to improve their CRF with exercise training and benefit from it considering long-term outcomes. We just need to find the most suitable exercise therapy mode for specific patient groups. CRF is related to the ability to transport oxygen from the lung to the mitochondria during exercise, regardless of the individual’s age. It is known that CRF depends on a chain of processes in multiple organs, including pulmonary ventilation, vascular function, left and right ventricular function, the ability of the vasculature