A small research project "deem[s] possible that exercising at a moderate pace may result in a more proper environment for the sperm production processes."

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PROBLEM: Lifestyle factors may impact men's reproductive capabilities: It's been variably suggested that bicycling, wearing skinny jeans, actually putting a laptop on your lap, and the use of drugs and alcohol can decrease sperm quality to some extent. In that same (moderately speculative) vein, might healthy habits help make sperm better, faster, and stronger?

METHODOLOGY: Researchers at the University of Cordoba collected the blood and semen of 31 men, 16 who had maintained a baseline of physical activity over the past year and 15 who they classified as sedentary. Their fitness level was tested in the lab. Those who got their exercise from bicycling were excluded. All were asked to abstain from both intercourse and exercise in the days leading up to the study.

The samples were evaluated based on the World Health Organization's sperm quality parameters, with attention paid to:

  • Volume - Anything under 1.5ml is considered hypospermia
  • Sperm count - About 20 million sperm per ml is typical
  • Motility - At least 32 percent of sperm should be able to propel themselves forward; velocity was also measured here
  • Sperm morphology - 4 or more percent of the sperm in a sample should be free of abnormalities

Also taken into consideration were color (the ideal is "opalescent and slightly yellow"), odor, pH, vitality, and viscosity. 

The blood samples were analyzed for the levels of the sex hormones FSH, LH, and testosterone, as well as for cortisol, a stress hormone associated with reduced sperm counts, and their T/C ratio, which indicates anabolic versus catabolic status (it has been suggested that a more anabolic state contributes to improved semen production).

RESULTS: The physically active men had faster sperm, a higher percentage of which could be classified as normal. Their sperm concentration and semen volume were also higher, but the difference did not reach statistical significance.

The physically active men also had higher levels of FSH, which is important for the creation of sperm, LH, which promotes testosterone secretion, and of testosterone itself. Their average T/C ratio was higher as well, and their cortisol levels tended to be lower, if not significantly so.

CONCLUSION: Moderate exercise appeared to be linked to superior hormone levels and healthier sperm characteristics.

IMPLICATION: In a previous study, the authors found intensive exercise to decrease the same qualities that here were improved by moderate physical activity. So be active, but don't work out too hard. 

The full study, "Physically active men show better semen parameters and hormone values than sedentary men " is published in the European Journal of Applied Physiology .

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