title: Long distance bicycle riding causes prostate-specific antigen to increase in men aged 50 years and over.
abstract: OBJECTIVE
  To investigate whether bicycle riding alters total prostate-specific antigen (tPSA) serum concentrations in healthy older men.
  
  
  METHODS
  129 male participants, ranging in age from 50 to 71 years (mean 55 years), rode in a recreational group bicycle ride of between 55 and 160 kilometers. Blood samples for tPSA analysis were drawn within 60 minutes before starting, and within 5 minutes after completing the ride. The pre-cycling and post-cycling tPSA values were log transformed for normality and compared using paired t-tests. Linear regression was used to assess the relationship between changes in tPSA with age and distance cycled.
  
  
  RESULTS
  Bicycle riding caused tPSA to increase by an average of 9.5% (95% CI = 6.1-12.9; p<0.001) or 0.23 ng/ml. The number of participants with an elevated tPSA (using the standard PSA normal range cut-off of 4.0 ng/ml) increased from two pre-cycle to six post-cycle (or from five to eight when using age-based normal ranges). Univariate linear regression analysis revealed that the change in tPSA was positively correlated with age and the distance cycled.
  
  
  CONCLUSIONS
  Cycling causes an average 9.5% increase in tPSA, in healthy male cyclists ≥50 years old, when measured within 5 minutes post cycling. We considered the increase clinically significant as the number of participants with an elevated PSA, according to established cut-offs, increased post-ride. Based on the research published to date, the authors suggest a 24-48 hour period of abstinence from cycling and ejaculation before a PSA test, to avoid spurious results.
authors: Department of Sports Medicine, Victorian Institute of Sport, Melbourne, Victoria, Australia. sandramejak@gmail.com
authors: Sandra L
authors: SL
authors: Mejak
authors: Julianne
authors: J
authors: Bayliss
authors: Shayne D
authors: SD
authors: Hanks
mesh_terms: D000368:Aged; D001642:Bicycling; D006801:Humans; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood / Q000175:diagnosis*; D012016:Reference Values
chemical_list: D017430:Prostate-Specific Antigen