Good news for two wheel road warriors - cycling does not make men infertile, impotent or have weaker bladders, a new study found.
It had been suggested the narrow saddles of bikes left men with genital numbness and saddle sores which affected their sexual health, including erectile dysfunction.
But a new study found cycling does not damage men's sexual or urinary functions and the cardiovascular benefits of recreational or intense cycling outweigh the small risks.
However the pressure from the saddle does put them at greater risk of getting a condition which makes it difficult to pee.
The impact of the increasing popular past time on a man's nether regions has received widespread publicity.
It had been suggested prolonged perineal pressure and micro-trauma during cycling damaged a man's private parts.
Small sample sizes
But previous studies lacked the use of validated measures or comparison groups, and were limited by small sample sizes.
So the University of California-San Francisco study recruited 2,774 cyclists through Facebook and cycle clubs, and 539 swimmers and 789 runners recruited as a comparison group.
In addition to the comparisons between similar athletic activities with and without perineal pressure, the researchers examined how cycling intensity, bicycle configuration, and even road conditions might impact sexual and urinary functions.
Cyclists were asked about their bike type, saddle type, saddle angle, frequency of wearing padded shorts while cycling, percent of time standing out of the saddle, handlebar height, and the type of surface on which they usually ride.
Cyclists were divided into a high intensity group of cycling more than two years more than three times per week, and averaging more than 25 miles per day and a low intensity group meeting none of these criteria.
Non-cyclists were defined as those who swim and/or run but do not cycle on a regular basis.
Participants completed validated questionnaires, including the Sexual Health Inventory for Men (SHIM), International Prostate Symptom Score (I-PSS), and National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI), as well as questions about urinary tract infections (UTIs), urethral strictures, genital numbness, and saddle sores.
Generally when compared to swimmers and runners, cyclists' sexual and urinary health was comparable, although some cyclists were more prone to urethral strictures.
Urethral stricture is the narrowing of a section of the urethra or 'water pipe' which carries urine from the bladder resulting in symptoms such as difficulties passing urine.
But those who were high intensity cyclists had overall better erectile function scores than low intensity cyclists.
Neither bicycle nor road characteristics appeared to have a negative impact on cyclists.
Standing more than 20 per cent of the time while cycling significantly reduced the odds of genital numbness.
Yet adjusting handlebar height lower than the saddle height did increase the likelihood of genital numbness and saddle sores.
Associate Professor Dr Benjamin Breyer of the Department of Urology said: "This is the largest comparative study to date, exploring the associations of cycling, bike and road characteristics with sexual and urinary function using validated questionnaires.
"We believe the results will be encouraging for cyclists.
"Cycling provides tremendous cardiovascular benefits and is low impact on joints.
"We believe the health benefits enjoyed by cyclists who ride safely will far out weight health risks.
"The comparison across athletes sampled in a similar way with validated instruments is what this study adds to the literature
"We're looking more closely at those who reported numbness to see if this is a predictor for future problems."
The study was published in The Journal of Urology.