Analyses Of Muscle Stress Biomarkers After Simulation Of Aquatic Rescue Performed By Military Lifeguards

Scientific Abstract Sample In 2022, the Military Fire Department of the State of Rio de Janeiro (FDRJ) carried out 16,027 drowning rescues. In this context, aiming to ameliorate this task execution by lifeguards, biomarkers of muscle damage could be used as an indirect measurement of muscle stress. PURPOSE: To analyze muscle stress biomarkers after a running and swimming route in a simulated drowning victim rescue. METHODS: Seventeen lifeguards (38.11 ± 3.33 years) were divided into two groups: Intervention Group (G1), n = 9, characterized by one repetition of maximal intensity, 300 m of running on the beach sand (close to the water) and 200 m of swimming in the sea without waves and currents with low intensity; and Control Group (G2), n = 8, which did not perform the aerobic test. Creatine Kinase (CK), Lactate Dehydrogenase (LDH) and Aldolase (AL) were analyzed following venipuncture through the antecubital vein before (t0), immediately after the test (t1) and 36 hours after the test (t2). RESULTS: The time of task execution was 301.88 ± 10.11 sec. (CV = 3.35). The values of CK were: in G1t0 = 138.41 ± 13.65 U/L versus G1t1 = 152.75 ± 6.40 U/L versus G1t2 = 635.05 ± 55.74; and in G2t0 = 145.92 ± 5.44 U/L. Comparing G2 with G1: Δ%G1(t0 → t2) = 358.81, pG1(t0 → t2) = 0.01, dG1(t0 → t2) = 43.3. The values of LDH were: in G1t0 = 343.46 ± 32.45 U/L x G1t1 = 399.28 ± 17.59 U/L x G1t2 = 374.96 ± 14.27 U/L; and in G2t0 = 352.44 ± 28.29 U/L. Comparing G2 with G1: Δ%G1(t0 → t2) = 9.18, pG1(t0 → t2) = 0.02, dG1(t0 → t2) = 1.3. The values of LA were: in G1t0 = 3.80 ± 0.15 U/L versus G1t1 = 3.94 ± 0.12 U/L versus G1t2 = 4.86 ± 0.26 U/L; and in G2t0 = 3.58 ± 0.3 U/L. Comparing G2 with G1: Δ%G1(t0 → t2) = 27.90, pG1(t0 → t2) = 0,01, dG1(t0 → t2) = 5.0). Differences were not observed in the values of CK, LDH and AL between G2(t0) and G2(t2). We found a significant association (p ≤ 0.05) evaluating the time of execution versus CK in t1. However, no significant association was verified in CK versus LDH, CK versus AL and LDH versus LA (p > 0.05) in t0, t1 and t2. CONCLUSION: Circulating levels of CK, LDH and AL significantly increased following the test thus indicating muscle injuries. The use of these biomarkers to monitor muscle stress contributes to equalize volume and intensity of loads in regular training aiming to improve performance, which might lead to a reduction in the risk of severe muscle injuries.