P-103 Physical fitness is positively associated with sperm quality in healthy young men
Authors: Pérez Prieto I.C , Plaza-Florido A , Molina N.M , Casas-Matas A , Molina M , Yoldi A , Vaquero Á , Navas P , Castilla J.A , Ortega F.B , Altmäe S 
Published: June 2022

Abstract

Study question
Do sperm quality parameters differ between “high” and “low” cardiorespiratory fitness (CRF) and muscular strength levels in healthy young men?

Summary answer
Self-reported CRF was positively associated with sperm count and concentration, while muscular strength (objectively measured and self-reported) did not correlate with seminal parameters.

What is known already
Physical activity (i.e., any body movement that results in energy expenditure) levels are positively associated with sperm quality parameters in healthy men. In this context, physical fitness, which is modifiable by physical activity, is a powerful marker of health that integrates several body functions such as hematocirculatory, skeletomuscular, phsychoneurological and endocrine-metabolic. In particular, the main components of physical fitness (i.e., CRF and muscular strength) have been negatively related to the risk of all-cause mortality in any age population. However, the association of CRF and muscular strength with sperm quality parameters in healthy young men is unknown.

Study design, size, duration
This cross-sectional study included 253 healthy men (age= 22.63 ± 5.04 years, BMI= 22.84 ± 1.33). Semen samples and physical fitness assessment were performed between March 2019 and July 2021 at the sperm biobank (Ceifer Biobank – NextClinics). The study was approved by the Ethics Committee of Investigación Biomédica de Andalucía.

Participants/materials, setting, methods
CRF was self-reported using the The International FItness Scale (IFIS). Muscular strength was objectively assessed using a handgrip dynamometer and self-reported with IFIS. Semen samples were analysed by clinical technicians to determine sperm count, sperm concentration and progressive motility. Analysis of covariance (ANCOVA) was performed to obtain adjusted mean differences on sperm quality parameters between high and low CRF and muscular strength groups after including age and body mass index as confounders.

Main results and the role of chance
Men with higher CRF presented increased sperm count and concentration compared to men with lower CRF values (adjusted mean differences 43.581 x 106 [2.630, 84.532; 95% confidence interval] and 10.131 x 106/ml [0.799, 19.463; 95% confidence interval]; both p &lt; 0.05). Muscular strength (objectively measured and self-reported) was not associated with any semen quality parameter (all p &gt; 0.05) when including age and body mass index as covariates.

Limitations, reasons for caution
This study reported a positive association between self-reported CRF using IFIS questionnaire and sperm count and concentration in healthy young men. Although the validity of the self-reported CRF using IFIS has been widely proved in healthy young adults, objectively measured CRF is needed to further confirm our findings.

Wider implications of the findings
Infertility has increased in the last decades. Therefore, more research is needed to identify health indicators that affect sperm quality. Our results suggest that self-reported CRF could contribute to the identification of young men with poor seminal quality and a higher risk of infertility later in life.

Trial registration number
NA