Date of Graduation


Document Type


Degree Name

Master of Science in Kinesiology (MS)

Degree Level



Health, Human Performance and Recreation


Brendon McDermott

Committee Member

Matthew Ganio

Second Committee Member

Stavros Kavouras


Health and environmental sciences, Cycling, Endurance, Heat, Observing, Renal


AIM: To observe the effects of endurance cycling in the heat on renal function, and determine if the extent of impairment is related to hydration. METHODS: 40 cyclists (34 male, 6 female, 52 ± 9 y, 21.7 ± 6.5 % body fat) completed an endurance cycling event (5.7 ± 1.2 hours) in the heat (33.2 ± 5.0ºC, 38.4 ± 10.7% RH). Body mass was assessed to determine net fluid loss, muscle damage in the legs was assessed with a pain scale, a urine sample was collected to analyze hydration status, and a blood sample was drawn. All measurements were taken pre- and post-event. Serum creatinine was measured by colorimetric assay and analyzed via the Jaffe reaction, and creatinine clearance was estimated. An ELISA kit was used to measure serum neutrophil gelatinase-associated lipocalin. RESULTS: A net fluid loss of 1.3 ± 1.1 kg was observed. Urine specific gravity (P < 0.001) and leg muscle pain (P < 0.001) increased post-event. Serum creatinine increased from pre- (0.52 ± 0.14 mg/dL) to post-event (0.88 ± 0.21 mg/dL; P < 0.001). Creatinine clearance decreased from pre- (160.9 ± 48.9 mL/min) to post-event (95.2 ± 28.1 mL/min; P < 0.001). Serum neutrophil gelatinase-associated lipocalin increased from pre- (68.51 ± 17.54) to post-event (139.12 ± 36.52; P < 0.001) CONCLUSION: Changes observed in renal measures suggest acute kidney injury and reduced kidney function after endurance cycling in the heat.