Renal function parameters during early and late recovery periods following an all-out 21-km run in trained adolescent runners

Abstract

This study investigated the changes in biomarkers of renal function and the corresponding estimated glomerular filtration rate (eGFR) in 10 male adolescent (16.2±0.6 years) trained runners during early and late recovery periods after an all-out 21-km run. Venous blood samples were taken immediately before, and at 2-h, 4-h, and 24-h following the 21-km run. Samples were analyzed for hemoglobin (Hb) and hematocrit (Hct), and serum urea (U), creatinine (Cr), creatine kinase (CK) and lactate dehydrogenase (LDH). U/Cr ratio, eGFR, and plasma volume change (%ΔPV) were calculated based on the associated measured variables. At 2-h and 4-h, there were increases (26%-146%) in U, Cr, U/Cr, CK, and LDH, and decreases (8%-13%) in Hb and Hct, as compared with the corresponding pre-exercise values. The calculated %ΔPV increased by 17% while the eGFR decreased 20% from the corresponding pre-exercise value, respectively. At 24-h, the changes of the blood variables and renal function parameters observed at early recovery period were sustained. Taken together, the findings of this study suggest that mild decline in renal function occurred during the early recovery period following the 21-km run. The decline in renal function did not return to normal during the later recovery period.