BACKGROUND: Exercise-Induced Muscle Damage Involves Cellular Disturbances Depending to The Intensity, Duration, Modality and Environments Conditions. Exacerbate Reactive Oxygen Species (ROS)
Contractile Dysfunction Resulting in Muscle Weakness and Fatigue (Kerksick and Zuhl, 2015). Myocytes Also Contain an Antioxidant Defense System That May Compensate the Oxidative Damage. However, Heat
Stress Causes a Disengagement of the Mitochondrial Respiratory Chain, Reducing Antioxidant Defenses and Resulting Oxidative Stress. The Aim of This Study Was to Investigate the Effects of Long-Term
Exercise On Muscle Damage and Redox Balance in Different Weather Conditions.
METHODS: Forty Male Endurance Runners Participated in This Study. Blood Samples (30 Ml) Were Collected 24 H Before, Immediately After, 24 H After, And 72 H After the São Paulo International Marathon
2014 (20 Runners, 30-35°C and Relative Humidity of 53%) And Marathon 2015 (20 Runners, 15-17°C and Relative Humidity of 82%). THE Following Parameters Were Carried Out: Superoxide Dismutase 3 (SOD 3),
Glutathione Peroxidase (GPX), Catalase (CAT), Creatine Kinase (CK), TBARS, CK-MB, ProBNP, Troponin, Myoglobin, And Lactate Dehydrogenase (LDH).
RESULTS: Marathon Race Induced an Increase On Troponin (22-Fold), Myoglobin (22-Fold), ProBNP (4-Fold) And TBARS (2-Fold) Immediately After Race and CK (7-Fold) And CKMB (7-Fold) 24 H After Race,
Indicating an Oxidative Stress, Cardiac and Muscle Damage. The Cardiac Muscle Markers and TBARS Returned to Their Initial Values 72 H After. The Weather Conditions Not Affects the Muscle Damage
Markers and TBARS. The Marathon Also Induced an Elevation On SOD3 Activity 24h After Race Just in Temperate Conditions. In Addition, SOD 3 Activity Was Smaller Both Before (1-Fold) And 24 H After
(2-Fold) In Hot Environment. In Contrast, GPx Activity Was Lower (1,5-Fold) In Temperate Environment and Its Below of the Established Standards. We Not Observed Changes On GPX and CAT After Marathon
in Temperate and Hot Environment.
DISCUSSION: Rhabdomyolysis Can Be Caused by Intense and Prolonged Exercise Causing Muscle Pain, Tenderness and Limited Mobility, having as Aggravating a Hot and Humid Environment (LATHAM J, 2002).
However, Few Studies Investigated the Combined Effect of Both Heat Stress and Exercise On the Redox Balance and Muscle Damage. Previous Study Observed That Hot Environment and Mild Exercise Increased
F2-Isoprostanes, While, Had No Impact On Lipid Hydroperoxides, As We Demonstrated by TBARS (MCANULTY Et Al., 2005). Knez and Périard (2014) Reported That the Hot Environment Does Not Exacerbate the
Oxidative Stress, But Significantly Elevates Antioxidant Capacity Match-Play Tennis and Suggest That Large Number of Balance Redox Parameters Should Be Investigated to Determine the Role of Oxidative
Stress in Different Environment. We Demonstrated That Marathon Race Induced Muscle Damage in The Same Extension in Hot and Temperate Environment. Interesting, The SOD3 Activity Decrease in Hot
Environment and This Changes Should Be Explored to Understand the Consequence of This Change in Different Environments.