Objectives: To investigate whether bicycle riding significantly alters total prostate-specific antigen (tPSA), free PSA (fPSA), and percent free PSA (%fPSA) serum concentrations in potential candidates for prostate cancer screening.
Methods: Thirty-three men, ranging in age from 50 to 74 years (mean 61 +/- 8), rode a 13-mile bicycle course. Blood samples for PSA analysis were drawn immediately before and 1 hour after cycling for 90 minutes. The precycling and postcycling tPSA, fPSA, and %fPSA values were compared using the Wilcoxon matched-pairs test, with P = 0.01 set as the significance level.
Results: Changes between precycling and postcycling values for tPSA (P = 0.517), fPSA (P = 0.048), and %fPSA (P = 0.166) were not statistically significant.
Conclusions: Physical activity combined with perineal pressure as induced by a 13-mile bicycle tour has no diagnostic impact on PSA values.