Effect of weightlifting upon left ventricular function and markers of cardiomyocyte damage

The current paradigm of cardiac troponin increase among athletes

Although it is known that exercise improves cardiovascular health and extends life expectancy, a significant number of people may also experience an elevation in cardiac troponin levels as a result of exercise. For many years, researchers have argued whether exercise-induced cardiac troponin rises are a consequence of a physiological or pathological reaction and whether they are clinically significant. Differences in cardiac troponin elevation and cardiac remodeling can be seen between athletes participating in different types of sports. When forecasting the exercise-induced cardiac troponin rise, there are many additional parameters to consider, as there is a large amount of interindividual heterogeneity in the degree of cardiac troponin elevation. Although it was previously believed that cardiac troponin increases in athletes represented a benign phenomenon, numerous recent studies disproved this notion by demonstrating that, in specific individuals, cardiac troponin increases may have clinical and prognostic repercussions. This review aims to examine the role of cardiac troponin in athletes and its role in various sporting contexts. This review also discusses potential prognostic and clinical implications, as well as future research methods, and provides a straightforward step-by-step algorithm to help clinicians interpret cardiac troponin rise in athletes in both ischemic and non-ischemic circumstances.

The Limits of Cardiac Performance: Can Too Much Exercise Damage the Heart?

Routine moderate-intensity physical activity confers numerous cardiovascular benefits and reduces all-cause mortality. However, the health impact of exercise doses that exceed contemporary physical activity guidelines remains incompletely understood, and an emerging body of literature suggests that high levels of exercise may have the capacity to damage the cardiovascular system. This review focuses on the contemporary controversies regarding high-dose exercise and cardiovascular morbidity and mortality. We discuss the limitations of available studies, explore potential mechanisms that may mediate exercise-related cardiac injury, and highlight the gaps in knowledge for future research.

Acute effect of intermittent and continuous aerobic exercise on release of cardiac troponin T in sedentary men

BACKGROUND

Studies have shown that acute exercise can increase serum concentrations of cardiac biomarkers, including cardiac troponin T (cTnT). We investigated the acute effects of intermittent (IE) and continuous (CE) exercise at the same cardiac workload on myocardial necrosis biomarkers in sedentary men.

METHODS

Eleven sedentary healthy men aged 22.3±1.9years completed the study. The subjects were divided into two groups and performed, in random order, IE (intensity alternating between 50% (2min) and 80% (1min) HRreserve) or CE (60% HRreserve). The study was designed as a single-blinded randomised crossover trial performed on two distinct experimental days separated by a 1-week washout period. Each session consisted of 40min of aerobic exercise, either IE or CE, on a treadmill. Blood samples were taken before (PRE), immediately after (POST) and 1h after (POST-1) each exercise session.

RESULTS

hs-cTnT significantly increased immediately after exercise in both protocols and remained elevated at POST-1 (P<0.05). There was no significant difference between POST and POST-1 values(P>0.05). Neither CE nor IE caused any significant change in CK-MB (P>0.05). The results also showed that HR and RPP increased significantly following both exercise protocols (P=0.001).

CONCLUSIONS

In summary, both CE and IE results in increased serum concentrations of hs-cTnT in sedentary men. However, this increase does not seem to be caused by the irreversible death of cardiomyocytes. CE resulted in a greater hs-cTnT concentration than IE.

Troponin and exercise

Cardiac troponins are the preferred biomarkers in diagnostic of myocardial infarction, but these markers also can rise in response to exercise. Multiple studies have assessed troponins post-exercise, but the results have varied and there have been disagreements about the mechanism of troponin release. The aim of this paper was to review the literature, and to consider factors and mechanisms regarding exercise-induced increase of troponin. 145 studies were found after a search in pubmed and inclusion of additional articles found in the reference list of the first articles. Results showed that troponin rises in 0-100% of subjects after prolonged heavy exercise like marathon, but also after short-term and intermittent exercise like 30min of running and basketball. The variation can be due to factors like intensity, age, training experience, variation in sample size, blood sample timing and troponin assay. The pattern of troponin level post-exercise corresponds to release from the cytosolic compartment of cardiomyocytes. Increased membrane permeability might be caused by production of reactive oxygen species or alterations in calcium, pH, glucose/fat metabolism or in communication between integrins. Other suggested mechanisms are increased cardiovascular stress, inflammation, vasculitis, release of troponin degradation products in "blebs", dehydration, impaired renal clearance and expression of cardiac troponin in skeletal muscle. It can be concluded that both heavy and light exercise may cause elevated troponin, which have to be considered when patient are suspected to have a myocardial infarction. Several factors probably influence post-exercise levels of troponin, but the mechanism of release is most likely physiologic.