Physiological Changes, Activity, and Stress During a 100-km–24-h Walking-March Long-distance loads such as ultramarathons are known to solve various metabolic and physiological changes in the human body.About very long stress at low intensities in healthy people is little known. The purpose of this study was to examine changes in body composition and metabolism for events with long endurance and low intensity. 25 male and 18 female healthy recreational athletes (34.6 ± 8.8 years; BMI: 22.4 ± 2.0 kg / m2) of the 100 km Mammoth March were recruited for participation in the 2014-2016 events. In addition to the classic ultramarathons, the mammoth march is a hiking event, where the participants run, but did not race or jog.It was expected that the 100 km route is covered within 24 hours, resulting in a calculated average speed of 4.17 km / h, which corresponds to the observed average speed (4.12 ± 0.76 km / h). Since not all participants reached the finish line, the comparison of finishers and non-finishers enabled a different evaluation of performance.The body composition measured by bioelectric impedance analysis was determined before and after the march, and serum samples were taken from the march at 30, 70 and 100 km to determine NT-PRO-BNP, troponin T, C-reactive protein (CRP)),Cortisol, lipoprotein low density (LDL), lipoprotein high density (HDL), triglycerides, total cholesterol, total creatine kinase (CK), CK-MB, aminotransferase (branch), old and sodium to determine. Nineteen participants carried ancient bracelets (Sensewear®) to obtain information about body activity and training intensity \ [metabolic equivalent of the task (MET) ].Sixteen participants carried mobile heart rate meters to determine the average heart rate during the race. Changes in serum parameters Over the race, Anova was analyzed with mixed effects and additional T tests.All serum parameters were analyzed on correlation with respect to various MET mirrors, speed, age, BMI, NT-Pro-BNP baseline, medium heart rate during race and gender with linear regression analysis. We found significant elevations for muscle and heart stress markers (CRP, CK, CK-MB, AST, ALT, Cortisol and NT-PRO-BNP) and decreasing markers for lipid metabolism (cholesterol, triglycerides, LDL). Although the intensity level demanded by our participants was low compared to other studies on ultramarathons, the change of the tested parameters was similar to high-intensive loads, e.g.B. showed NT-PRO-BNP a four-times increase and a decrease in the LDL by 20%. In addition to the training period, age, BMI, training status and gender are relevant parameters that influence the increase in stress factors.In particular, our data indicates that NT-PRO-BNP could be a marker for cardiovascular fitness even in healthy adults. This low intensity march highlighted a strong systemic reaction and great cell stress and moved to a favorable lipid profile comparable to higher intensity loads.
Despite increasing increase in parameters for a heart failure, there was no indication of damage to the heart cells.Remarkably, the duration seems to have a greater impact on parameters for a heart failure and metabolism than the intensity. The study can be found under https://www.frontiersin.org/articles/10.3389/fhys.2021.640710/full