Impact of Ad Libitum Hydration on Muscle Damage and Electrolyte Balance in Ultra-Trail: A Heatmap Analysis of Biomarkers and Race Characteristics

• DOI: 10.20944/preprints202412.1315.v1
• Publication Date: 2024-12-17T07:45:26Z
• Authors: Alejandro García-...; Francisco Pradas; Miguel Lecina; Nicolae Ochiana; Carlos Castellar-...

Ultra-trail races (UT) pose significant challenges to maintaining hydration and electrolyte balance, with risks of dehydration (DH), overhydration (OH), exercise-associated hyponatremia (EAH), exertional rhabdomyolysis (ER). This study examined the effects ad libitum (ADL) on status muscle damage during a nine-stage UT (635 km, 40,586 m elevation gain). Four highly trained male athletes participated. Hydration was assessed via body weight loss (BWL), urine specific gravity (Usg), serum sodium ([Na+]), while markers included creatine kinase (CK), lactate dehydrogenase (LDH), calcium (Ca). Results showed no cases EAH or hypernatremia ([Na+] >145 mmol·L−1), [Na+] maintained above 135 mmol·L−1. BWL exceeded 2% DH threshold in early stages (p=0.029), Usg remained elevated (>1.020 g·mL−1). LDH CK significantly increased at all (p<0.05), persisting 48 hours post-event. Correlations aggravated (r=0.47 CK) hypocalcemia (r=−0.68 Ca). Elevation gain/loss amplified fluid injury. While ADL mitigated EAH, it did not fully address damage. Personalized recovery protocols are crucial optimizing performance health races.