Aerobic Exercise under Cold Conditions May Affect the Cardiac Structure by Elevating the Galectin 3 and CK-MB Levels

]) participated in this study. Athletes and physically active individuals performed 40 minutes of acute aerobic running exercises at 0°C and 20°C environmental temperatures. Gal-3 and CK-MB levels were measured pre- and post-exercise. Baseline Gal-3 levels of professional athletes (p < 0.001) and physically active individuals (p = 0.048) were significantly higher than those of sedentary individuals. Two-way ANOVA showed significant interaction (p = 0.035) between temperature (0°C vs. 20°C) and exercise (pre- vs. post-exercise). At 0°C, there was a significant increase in post-exercise serum Gal-3 levels when compared with pre-exercise values (p < 0.001, +7.1%), whereas no significant difference was observed at 20°C. Moreover, no significant interaction was found for CK-MB levels (p = 0.306) between the temperature (0°C vs. 20°C) and exercise (pre- vs. post-exercise). Additionally, there was a significant difference between pre- and post-exercise values at the 0°C environmental temperature for serum CK-MB levels (p < 0.001), while there was no significant difference at 20°C. This study demonstrates that regular exercise is associated with biochemical abnormalities that may affect cardiac structure and function. Aerobic exercise under cold conditions may cause myocardial injury.