The aim of the present study was to examine the acute effect of an ultra-endurance performance on N-terminal pro-brain natriuretic peptide (NT-proBNP), cardiac specific troponin T (cTnT), creatinine kinase-myocardial band (CK-MB), high sensitive C-reactive protein (hsCRP), ischemia modified albumin (IMA), heart-type fatty acid binding protein (H-FABP) and cardiovascular function. Cardiac biomarkers were evaluated in 14 male ultra-marathoners (age 40 ± 12 years) during a 24 h ultra-marathon at five points (i.e., Pre-race; Marathon, 12-h run, 24-h run, and 48-h post-race). All subjects underwent baseline echocardiography assessment at least 10 days prior to the ultra-marathon and 48 h post-race. The average distance covered during the race was 149.4 ± 33.0 km. Running the ultra-marathon led to a progressive increase in hsCRP and H-FABP concentrations (p < 0.001). CK-MB and cTnT levels were higher after a 24-h run compared to pre-race (p < 0.05). Diastolic function was altered post-race characterized by a reduction in peak early to late diastolic filling (p < 0.01). Running an ultra-marathon significantly stimulates specific cardiac biomarkers; however, the dynamic of secretion of biomarkers linked to myocardium ischemia were differentially regulated during the ultra-marathon race. It is suggested that both exercise duration and intensity play a crucial role in cardiovascular adaptive mechanisms and cause risk of cardiac stress in ultra-marathoners.

Proper functioning of the respiratory system is one of the most important determinants of human health. According to current knowledge, the diaphragmatic breathing pattern seems to be the most favourable. However, recent reports indicate that athletes often have dysfunctional breathing patterns, which may be associated with an increased risk of musculoskeletal injuries. The influence of the type of breathing pattern on the mechanical airways in athletes has not been investigated. The aim of the present study was to determine the characteristics and relationships between breathing patterns and respiratory function in athletes. This study included 69 Polish elite endurance athletes (♂40, ♀29) in different sports disciplines and 44 (♂17, ♀27) healthy nonathletes as a control group. All participants underwent pulmonary function tests (spirometry, plethysmography, diffusion capacity for carbon monoxide) with assessment of breathing patterns by the Hi–Lo test. Inspiratory and expiratory resistance (R) and reactance (X) of the respiratory system at a given frequency (5 Hz, 11 Hz, and 19 Hz) were measured by a noninvasive forced oscillation technique. In this study, almost half of the athletes (44.92%) had dysfunctional breathing patterns, although at a lower rate than that in the control group. Diaphragmatic breathing patterns were characterized by higher spirometric, plethysmographic and DLCO values compared to thoracic or abdominal breathing patterns. Similarly, lower inspiratory reactance at 5 Hz (X5%pred.) was observed in the diaphragmatic pattern compared to the thoracic pattern. A diaphragmatic breathing pattern is associated with better pulmonary function test results. However, this study revealed a dysfunctional breathing pattern in almost half of the athletes. These results suggest that the assessment of breathing patterns and the implementation of breathing exercises in athletes are essential to promote proper breathing patterns.

The aim of this study was to evaluate selected parameters of strain and rotation of the left ventricle (the basal rotation (BR) index, the basal circumferential strain (BCS) index, and the global longitudinal strain (GLS) of the left ventricle) in male athletes with physiological cardiac hypertrophy (LVH group), and athletes (non-LVH group) and non-athletes without hypertrophy (control group, CG). They were evaluated using transthoracic echocardiography and speckle tracking echocardiography before and after an incremental exercise test. The LVH group demonstrated lower BR at rest than the non-LVH group (p < 0.05) and the CG (p < 0.05). Physical effort had no effect on BR, nor was this effect different between groups (p > 0.05). There was a combined influence of LVH and physical effort on BR (F = 5.70; p < 0.05) and BCS (F = 4.97; p < 0.05), but no significant differences in BCS and GLS at rest between the groups. A higher BCS and lower GLS after exercise in the LVH group were demonstrated in comparison with the CG (p < 0.05). Left ventricular basal rotation as well as longitudinal and circumferential strains showed less of a difference between rest and after physical effort in subjects with significant myocardial hypertrophy. In conclusion, the obtained results may suggest that echocardiographic assessment of basal rotation and circumferential strain of the left ventricular can be important in predicting cardiac disorders caused by physical effort in individuals with physiological and pathological heart hypertrophy.

This study investigated the effect of high-intensity interval training (HIIT) in normobaric hypoxia on aerobic performance in young biathlon athletes. In addition, the study aimed to assess the impact of training in hypoxia on the mechanisms of exercise-induced motor performance fatigue. In a randomized, controlled crossover study twelve athletes (age 15.7 ± 1.0 years) completed a HIIT in normobaric hypoxia (hypoxia training) (fraction of inspired oxygen, FiO2 = 15.2%) and normoxia (normoxia training) in a randomized order. The HIIT was performed 3 days/week for 6 weeks (3 weeks in hypoxia and 3 weeks in normoxia, with a 3 week wash-out period in between) and consisted of 5 x 4 minutes running (80% of peak oxygen uptake), separated by 3 minutes of active recovery and 4 x 1minute arm cranking (60% peak power), interspersed with a 2 minute rest. Peak oxygen uptake (V̇O2peak), hypoxia-inducible factor 1 alpha (HIF1α), vascular endothelial growth factor (VEGF), pro-inflammatory cytokines, muscle damage biomarkers and total antioxidant status were analyzed before and after both training protocols (HT and NT). A significant effect of hypoxia on V̇O2peak (ηp2 = 0.321, p = 0.044) and hypoxia and training on V̇O2LT and haemoglobin concentrations (ηp2 = 0.689 p = 0.001) were observed. The V̇O2peak was significantly higher post-HT compared to pre-HT (p < 0.01). A significant effect of oxygen conditions and training on the serum post-exercise VEGF (ηp2 = 0.352, p = 0.033) and myoglobin concentrations (ηp2 = 0.647 p = 0.001) was found. A significant effect of hypoxia was also observed for cytokines levels: interleukin-6 (ηp2 = 0.324 p = 0.042), tumour necrosis factor alpha (ηp2 = 0.474 p = 0.009) and transforming growth factor beta (ηp2= 0.410, p = 0.018) with a non-significant effect on antioxidant status. This study shows significant differences in the aerobic performance and biomarkers of muscle damage after exposure to hypoxia training. These findings highlight that HIIT in hypoxia is sufficient to enhance aerobic performance and may also reduce skeletal muscle susceptibility to fatigue in young biathletes.