Can heavy exercise make me bleed more or have breakthrough bleeds?

Vigorous exercise can influence your menstrual cycle, potentially leading to breakthrough bleeding. This occurs because intense physical activity can disrupt your body's delicate hormonal balance, which plays a crucial role in regulating your menstrual cycle. Here's a closer look at the relationship between exercise and your menstrual cycle.

Light to moderate exercise

Generally, it doesn't affect your menstrual cycle. In fact, it can be beneficial for your overall health and may even help regulate your cycle.

Regular, moderate-intensity exercise can be a powerful ally for your menstrual health. Far from causing disruptions, it can actually help regulate your cycle.

Here's how:

• Hormonal Balance: Moderate exercise can help regulate hormones like estrogen and progesterone, which are key players in the menstrual cycle.
• Reduced Stress: Physical activity is a well-known stress reliever. Stress can disrupt hormone levels and lead to irregular periods.
• Improved Blood Flow: Exercise enhances blood circulation, ensuring that your reproductive organs receive adequate oxygen and nutrients.

Heavy to Vigorous Exercise

While moderate exercise can benefit your menstrual health, excessive physical activity can lead to various menstrual irregularities. Here's a breakdown of the potential effects:

• Lighter Periods: Intense workouts can lower body fat percentage, which can, in turn, reduce estrogen production. Lower estrogen levels can result in lighter menstrual flow. A healthy body fat percentage is crucial for optimal hormonal function, including the regulation of your menstrual cycle. When body fat levels drop too low, it can signal to your body that it's not in a state conducive to reproduction. As a result, your body may reduce the production of hormones like estrogen, leading to lighter or even absent periods. From 21% to 31% is considered a healthy range for the average female.
• Irregular Periods: The physical and psychological stress associated with heavy exercise can disrupt the delicate hormonal balance necessary for a regular menstrual cycle. This can lead to irregular periods, where the timing and flow vary significantly.
• Missed Periods: Athletes and individuals who engage in intense training for extended periods often experience missed or delayed periods. This condition, known as functional hypothalamic amenorrhea, occurs when the hypothalamus, a brain region that regulates hormones, is suppressed due to stress and energy imbalance.
• Breakthrough Bleeding: Intense exercise can trigger hormonal fluctuations and stress, leading to unexpected bleeding between periods. This can be particularly common in women who are already prone to irregular cycles or hormonal imbalances.

If you're concerned about how exercise is affecting your menstrual cycle, it's important to talk to your doctor. They can help you determine if your exercise routine is healthy for you and make sure that any changes in your menstrual cycle are not due to an underlying medical condition.

References

Thiyagarajan DK, Basit H, Jeanmonod R. Physiology, Menstrual Cycle. [Updated 2024 Sep 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK500020/

Ahrens KA, Vladutiu CJ, Mumford SL, Schliep KC, Perkins NJ, Wactawski-Wende J, Schisterman EF. The effect of physical activity across the menstrual cycle on reproductive function. Ann Epidemiol. 2014 Feb;24(2):127-34. doi: 10.1016/j.annepidem.2013.11.002. Epub 2013 Nov 15. PMID: 24345590; PMCID: PMC3946734.

MacGregor KA, Gallagher IJ, Moran CN. Relationship Between Insulin Sensitivity and Menstrual Cycle Is Modified by BMI, Fitness, and Physical Activity in NHANES. J Clin Endocrinol Metab. 2021 Sep 27;106(10):2979-2990. doi: 10.1210/clinem/dgab415. PMID: 34111293; PMCID: PMC8475204.