Inflammatory, hematological and oxidative stress responses in 160 to 246 km ultramarathons

Every race with distance higher than marathon is called ultramarathon. There are short ultramarathons, with a distance of 50 to 100km, such as the Comrade Marathon in South Africa (89km). On the other hand there are the long ultramarathons ranging from 100 to 1600km. Among these we can highlight the Western States Endurance Run (160km) in California/USA; the Badwater Ultramarathon (216 km) in California/USA and the Spartahlon Ultramarathon (246 km) in Greece. This literature review aimed to verify the inflammatory, hematological and oxidative stress responses particularly induced by these ultramarathons ranging from 160 to 246 km. These races present long distance and moderate intensity exercise characteristic, with potential systemic inflammatory response. There are pronounced increase in post-race pro and anti-inflammatory cytokines such as interleukins 10, 1ra, 6 and 8, as well as C-reactive protein, representing the acute phase of inflammation. In terms of post-race hematological responses, pronounced increase in white cell count are observed, indicating pronounced disturbance in the count of immune cells, and reduction in the count of red blood cells and platelets. In terms of oxidative stress, both pro and antioxidant capacities are affected post-race. Lipid hydroperoxides and 8-iso-prostaglandin-F2a, markers of oxidative stress related to lipid peroxidation, as well as biomarkers of antioxidant capacity as total antioxidant capacity , uric acid and bilirubin, are increased. Thus we can conclude that 160 to 246 km ultramarathons trigger inflammatory responses, disturbance in the counting of blood cells and oxidative stress. This knowledge provides the basis both for training prescription as a recovery after the race for the athletes and their coaches

Effects of fasting on critical velocity and anaerobic capacity determination in running rats

The non-invasive critical power model suggested for aerobic/anaerobic evaluation of human beings was adapted for rats in our Laboratory. The aim of the present study was to verify the effects of 12-hours fasting on the critical velocity (CV) and the anaerobic running capacity (ARC) determination in sedentary rats. 11 adult Wistar rats (90 days old, weighing 395.5 ± 17.6g) were submitted to four exercise tests at 25, 30, 35 and 40m/min (with 48 hours of interval), performed randomly and continuously until exhaustion, for the CV and ARC estimations. The protocol was executed with the rats in the fed state and after 12-hours fasting. The hyperbolic curve velocity versus time to exhaustion (tlim) was linearized to V = CV + ARC/tlim, where the CV and ARC were the linear and slope coefficients, respectively. For comparison of the parameters obtained in the fed state and after fasting, the Student t test for dependent measures was used (p\u3c0.05). The CV (m/min) and ARC (m) were 25.5 ± 1.5 and 21.8 ± 16.4 m in fed state and 22.5 ± 4.2 and 25.9 ± 14.0 m after fasting. The linear regression showed significant values (R2=0.85±0.07 in fed state and 0.88±0.09 after fasting). The 12-hours fasting modified the CV without changing ARC. The results indicate that there is a caution need with the alimentary condition of running rats previously to evaluation test. The physiological characteristics can mask the determination of the aerobic condition, resulting in the inadequate exercise prescription based on the parameters estimated by the non-invasive protocol

Anaerobic And Aerobic Performances In Elite Basketball Players.

THE PURPOSE OF THIS STUDY WAS TO PROPOSE A SPECIFIC LACTATE MINIMUM TEST FOR ELITE BASKETBALL PLAYERS CONSIDERING THE: Running Anaerobic Sprint Test (RAST) as a hyperlactatemia inductor, short distances (specific distance, 20 m) during progressive intensity and mathematical analysis to interpret aerobic and anaerobic variables. The basketball players were assigned to four groups: All positions (n=26), Guard (n= 7), Forward (n=11) and Center (n=8). The hyperlactatemia elevation (RAST) method consisted of 6 maximum sprints over 35 m separated by 10 s of recovery. The progressive phase of the lactate minimum test consisted of 5 stages controlled by an electronic metronome (8.0, 9.0, 10.0, 11.0 and 12.0 km/h) over a 20 m distance. The RAST variables and the lactate values were analyzed using visual and mathematical models. The intensity of the lactate minimum test, determined by a visual method, reduced in relation to polynomial fits (2nd degree) for the Small Forward positions and General groups. The Power and Fatigue Index values, determined by both methods, visual and 3rd degree polynomial, were not significantly different between the groups. In conclusion, the RAST is an excellent hyperlactatemia inductor and the progressive intensity of lactate minimum test using short distances (20 m) can be specifically used to evaluate the aerobic capacity of basketball players. In addition, no differences were observed between the visual and polynomial methods for RAST variables, but lactate minimum intensity was influenced by the method of analysis.42137-4

Swimming rats’ model: influence of age and density on the maximal lactate steady state test

The aim of this study was to verify wether the density plays a significant role in the swimming model for rats. To verify such possibility the rats’ weight in the water was considered as an additional workload beyond the load increment. Forty Wistar rats divided in groups of 90, 120 and 210 days old were used. The animals had their hydrostatic weight and density determined by an apparatus for water weighing. Later, all the rats were evaluated at the maximal lactate steady state (MLSS) test adapted for swimming rats. Statistic Analysis was performed by Anova one-way and Scheffé post hoc test (p\u3c0.05). Results showed hydrostatic weight (g) and density (g/cm3) of 10.2 and 0.997, 16.8 and 1.011, 21.4 and 1.017 for G90, G120 and G210, respectively, with significant differences between ages. Blood lactate concentrations at the MLSS were 4.1, 4.8 and 5.5 mmol/L for G90, G120 and G210, respectively and were not significantly different; but it showed a trend to increase in agreement with the presented ages. In contrast, the workloads seemed to decrease with age in the conventional method (5.3, 4.7, 4.5% of body weight for G90, G120 and G210, respectively), however when the hydrostatic weight was considered, an increase in effort was found in agreement with age (7.9, 8.4, 8.5% of body weight for G90, G120 and G210, respectively). This fact could be an explanation for the higher lactate concentration found in older groups. So, it is possible to suggest that in the convencional workload method the 210 days group has its aerobic capacity underestimated because these rats are denser than those 90 days animals

Complex network models reveal correlations among network metrics, exercise intensity and role of body changes in the fatigue process

The article of record as published may be located at https://doi.org/10.1038/srep10489The aims of the present study were analyze the fatigue process at distinct intensity efforts and to investigate its occurrence as interactions at distinct body changes during exercise, using complex network models. For this, participants were submitted to four different running intensities until exhaustion, accomplished in a non-motorized treadmill using a tethered system. The intensities were selected according to critical power model. Mechanical (force, peak power, mean power, velocity and work) and physiological related parameters (heart rate, blood lactate, time until peak blood lactate concentration (lactate time), lean mass, anaerobic and aerobic capacities) and IPAQ score were obtained during exercises and it was used to construction of four complex network models. Such models have both, theoretical and mathematical value, and enables us to perceive new insights that go beyond conventional analysis. From these, we ranked the influences of each node at the fatigue process. Our results shows that nodes, links and network metrics are sensibility according to increase of efforts intensities, been the velocity a key factor to exercise maintenance at models/intensities 1 and 2 (higher time efforts) and force and power at models 3 and 4, highlighting mechanical variables in the exhaustion occurrence and even training prescription applications