How does physical inactivity and body composition affect fertility?

This study investigated if physical inactivity (PI), sedentary behavior (SB) and body composition (BC) are linked to infertility. They found that PI and SB may increase the risk of infertility.

Infertility is an increasingly common problem. In many cases the cause of infertile is unclear. Physical inactivity (PI) and sedentary behavior (SB) are major health concerns. PI and SB can have negative effects on overall health. PI is considered less than 150 minutes of activity per week. SB is any task that requires a low level of energy. 

Some patients can be physically active but also have SB. PI and SB are linked to poorer health and higher mortality. Some studies suggest PI and SB may be linked to infertility. Being overweight or obese is associated with infertility. Body composition (BC) is a term used to describe the distribution of fat and lean tissue in the body. Few studies have investigated the effect of BC on fertility. It is unclear if there is an association between PI, SB, and BC in infertile couples. 

This study included 302 participants. 159 of these were infertile. Infertile participants had unexplained infertility. Participants were asked to complete a questionnaire. Information on diet, physical activity (PA) and SB was evaluated. BC was assessed using a number of measures. These included body mass index (BMI; a measurement of body weight in relation to height), waist circumference (WC) and body fat measurements.  

Infertile participants were more likely to have greater BMI, WC, and body fat. PA levels were similar in fertile and infertile patients. Infertile men were less likely to undergo vigorous PA. PI was associated with SB in infertile men. Fertile men with high PA had lower body fat. The majority of women in the study had low PA levels.

The risk of infertility was 2.2 times higher in men with PI 2.83 times higher in men with body fat higher than normal. In women, the risk of infertility was 3.61 times higher in those with greater SB. Women with high body fat were 3.16 times more likely to have infertility. Also, women with low fat-free mass (lean body tissue) were 2.65 times more likely to have infertility. PA was not associated with female infertility.

The authors concluded that physical inactivity and sedentary behavior may increase the risk of infertility in both men and women.

PA and SB were self-reported. This can lead to biased results. This study only included couples with unexplained infertility. More studies are needed.

 If you have any concerns regarding infertility please consult with your doctor.