The influence of work intensity on postexercise proteinuria.

Fifteen men were studied during 100 m, 400 m and 3,000 m runs at maximal speed to determine total urinary protein and albumin excretion rates in relation to different distances of running. Venous blood lactate rose to 7.5 mmol.l-1 after the 100 m and 3,000 m events, while reaching 12 mmol.l-1 after the 400 m dash. Total urinary protein excretion increased to 330, 1640 and 565 micrograms.min-1 after the 100 m, 400 m and 3,000 m runs respectively, as compared with basal values (70 micrograms.min-1). In the meantime, albumin excretion increased respectively by 5, 25 and 18 fold of the resting values. The renal clearance of albumin increased to 0.84, 5.62 and 3.35 microliter.min-1 after the three runs, as compared with a mean value of 0.19 microliter.min-1 at rest. Exponential relationships (r = 0.85) were recorded between post-exercise venous lactate and albumin, and total protein excretion. The present work illustrates the major influence of the intensity of exercise (anaerobic glycolytic component), rather than its duration, on the excretion rate of urinary proteins.