Effects of sauna on sperm movement characteristics
of normal men measured by computer-assisted sperm
analysis
J. SAIKHUN*, Y. KITIYANANT*, V. VANADURONGWAN
and K. PAVASUTHIPAISIT*
*Department of Anatomy, Faculty of Science and Institute of Science and Technology, Mahidol
University, Bangkok 10400, Thailand, and College of Sports Science and Technology, Mahidol
University, Nakhon, Pathom 73170, Thailand
Summary
The effects of sauna exposure on sperm movement characteristics and other semen
parameters were evaluated using computer-assisted sperm analysis (CASA). A signi®cant
(p < 0.01) decrease in average path velocity (VAP), curvilinear velocity (VCL) and
amplitude of lateral head displacement (ALH) was found after exposure to sauna for 2
weeks. The altered parameters returned to their original values within 1 week after
cessation of sauna exposure. Mean values for semen volume, sperm count, percentage
motility, sperm morphology and sperm penetration assay (SPA) were not statistically
different during and after sauna, when compared to the corresponding control values.
The results suggest that increasing scrotal temperature by sauna causes a reversible
decrease in sperm movement parameters.
Keywords: CASA, sauna, semen quality, SPA, sperm movement characteristics
Introduction
In numerous mammal species, including man, testicular
temperature is lower than core body temperature. In man,
scrotal temperature is 2±3 °C lower than rectal temperature
and the optimum temperature for human spermatogenesis is
considered to be 35 °C. The deleterious effect of heat on
spermatogenic function of the testes has been studied by
several groups of investigators. The elevation of intrascrotal
temperature resulting from varicocele has been suggested as
one of the causes for the deterioration of spermatogenesis in
such patients (Zorgniotti & McLeod, 1973). It has been
found that the higher the scrotal temperature in infertile men,
the more altered are their sperm characteristics (Mieusset
et al., 1987c; reviewed in Mieusset & Bujan,