Physical activity is essential for good health and that is a fact (source). Exercise in general has been found to help with our mental well-being as well as some protection from obesity, cardiovascular disease, hypertension, diabetes, and osteoporosis (source). But what about fertility? If you've done any online research on exercise and fertility, you may find more articles on how exercise can hurt fertility, rather than help. Indeed, some research shows that too much exercise can harm fertility.
With only 31.8% of Americans getting the recommended amount of exercise per week, however, the problem for the majority of us isn’t doing too much exercise, but not getting enough (source).
How Exercise Improves Fertility:
When done right, exercise has been found to help with fertility by 1) increasing insulin sensitivity, which improves ovarian function and the chance of conception (source), 2) improving rates of implantation and pregnancy as well as reduce the risk of miscarriage (source) and 3) as a key component to managing weight, which is essential for getting pregnant due to hormonal imbalances that can occur with excessive weight.
Bottom line is that when it comes to fertility, the question is not whether or not you should exercise, but rather how much and how intensely should you exercise. The current recommendation to exercise ‘right’ for women trying to conceive is to do moderate physical activity. Moderate physical activity has been associated with a small increase in fertility regardless of your body mass index (BMI) (source)
When Can Exercise be Harmful to Fertility?
Research shows that if you are of normal weight or underweight, the more exercise you do and the more intense you do it, the longer it may take for you to conceive. Specifically, if you exercise vigorously for more than an hour per day, your fertility may be negatively impacted. This does not appear to apply, however, to women who are overweight or obese (source).
What is more important than weight and BMI, however, is your actual percent body fat. If you work out intensely and are athletic, you may have a normal or even high BMI, but be very muscular and lean. If that is the case, you may not have enough body fat to have regular ovulatory cycles. You may also have a normal BMI but have too much fat. Having too much fat can also disrupt your hormones that impact a healthy ovulation cycle.
If you have irregular or missed periods, than that is a pretty big indicator that your weight and/or exercise program may be interfering with ovulation. You can meet with an exercise physiologist to measure your percent body fat. From there you he or she can help you develop an exercise program tailored to your needs.
Recommendations for Safe Exercise for Fertilty :
Do: At a minimum, perform 150 minutes of moderate exercise per week (source).
Do: What is the best type of exercise? The type that you will do. Pick a type of physical activity that suits your lifestyle such as brisk walking, swimming or gardening. One study that followed 3,628 women trying to conceive, found that physical activity of any type might improve fertility among overweight and obese women (source).
Do: Add a safe weekly strength training regime in addition to endurance training. Check out a strength training workout plan here (source).
Do: If you are lean and work out vigorously, it is recommended to substitute your vigorous exercise with moderate exercise to potentially improve your fertility (source).
What about Exercise for Weight Loss to Improve Fertility?
If you are overweight or obese, it is recommended to exercise and lose weight for increased fertility (source). To lose weight by exercise, the amount of recommended level of exercise, the American College of Sports Medicine recommends exercise to be above the minimum levels of 150 minutes per week. A general rule of thumb for weight loss is to increase aerobic physical activity of moderate intensity to 225-420 minutes a week. However, to successfully lose weight, you should speak to your doctor about a safe exercise and caloric restriction program.
As mentioned above, if you are overweight or obese, you may be able to work out at this level with a positive impact on fertility. It’s important that you accompany your exercise regime with a nutritious diet with the right amount of protein (either animal or plant). Since physical activity has a major role in keeping the weight off, you should also have a program in place for a safe pregnancy and post pregnancy workout regime (source).
What about your partner?
Your partner should be on board with exercise as well. Not only is it good for moral support, but exercise can help improve sperm quality as well (source). Please note, however, that bicycling more than five hours per week has been demonstrated to have a negative correlation with both total motile sperm counts (OR 2.05) and sperm concentration (OR 1.92) (source).