Study On The Changes Of Lactate And MDA In The Blood During Incremental Exercise

Objective: Animal studies show that both of LA and ROS appeared the suddenly increase point by incremental exercise to exhaustion, and the regular phenomenon is that ROS suddenly increase point always appear after the lactate threshold. But the same regular pattern in body needs to further study. Observe the dynamic changes of lactate, MDA, CK and H2O2 in human blood during incremental exercise to exhaustion and recovery. Verify the “MDA suddenly increase point” exists in human; confirmed that the sudden increase points phase between lactate and MDA in blood was difference; analyze the relationship between oxidative damage and exercise intensity. This study may provide a theoretical and experimental basis for the overload training athletic sports about how to develop a reasonable exercise intensity and prevent the body peroxidation damage.Contents: During incremental exercise to exhaustion and recovery by power bike:1.detect the content or activity change of lactate、MDA、CK and H2O2 in different intensity and time; 2. analyze the dynamic curve of MDA in blood whether suddenly increase; 3.observe the order of suddenly increase points in lactate and MDA; 4. analyze correlation or causality between the indicators.Methods: Hebei Normal University Sports Institute, the 15 male students increasing loads to exhaustive exercise. Collect the end of each load and recovery of blood, detect lactic acid, MDA, CK and H2O2. Exercise program: set up 6 levels load(E1、E2、E3、E4、E5、E6),each load lasts 3min, the increase load of each level is 50 W, the starting load is E1=0W, the maximum load is E6=250W. Recovery program: set up 2 stages(R1, R2), each stage is 15 min.Blood collection program: the blood was drawn from elbow vein after the end of each load and recovery. Y integrated catheter was used for blood collection. Detection scheme: in strict accordance with the kit instructions to detect the serum biochemical indicators.Results:1.The concentration of lactate increased with the increasing load, decreased with the recovery, after E3 phase, compared to the adjacent loading was significantly elevate(P<0.01).2.The change of MDA content, from E1 to E5 increasing trend has no obvious(E1=1.17±0.29nmol/ml, E5=1.29±0.22nmol/ml), compare with two adjacent load has no significant difference(P> 0.05). E6 compared with E5 has very significant increase(E6 =1.76±0.30nmol/ml, P<0.01); with the end of the exercise the content of MDA is gradually reduced.3.The concentration of H2O2 rise with the increasing load, from E1 to E5, compare with two adjacent load has no significant difference(P>0.05); E6 compared with E5 has significant increase; the serum trend change of MDA and H2O2 is consistent.4. In serum CK rises with the load increases, and continued to increase until the end of the R1 phase after exercise. R1 compared with E6 has very significant increase(P<0.01).5. The suddenly increase point of lactate appeared in E3 and MDA appears in E5; lactate,MDA and H2O2 concentration peaks appeared in E6, CK activity peaks appeared in R1.Conclusion:1.Confirm the objective existence MDA suddenly increase point in human.2. After the MDA suddenly increase point appears, CK tended to increase significantly.This shows that the sudden increase in MDA as a point indirectly detect ROS index may lead to increased damage to the critical point. The results suggest that exercise training in addition to monitoring indicators of exercise intensity by blood lactate suddenly increase point, the blood MDA suddenly increase point can also be used as the upper limit of the intensity of monitoring.3. Discovery of the MDA threshold and find a detection limit of free radicals,that mean the proper level of ROS is good for the human body, but too much is harmful. These results can provide a safe load range for overload training, and provide quantitative standards for monitoring safety training.