by Dr. Irina Fedulow-Plante PT DPT-W

In recent years, there has been tremendous growth in backcountry sporting activities, both professional and recreational. Due to increased access to the backcountry, advancing medical technology and overall growing interest in wilderness sports, research is starting to focus on the physiological effects when in more austere environments. More women are partaking in wilderness activities and the research looking at the effects of altitude on the female body is slowly gaining momentum.

While traveling to altitude is an exciting endeavor, many factors need to be considered. The classifications for altitude are low altitude: 1,640-6,650 ft, moderate altitude: 6,650-9,840 ft, high altitude: 9,840-18,040 ft and extreme altitude: >18,040. It’s important to gradually acclimate to altitude and expect potential side effects such as nausea, anxiety, headache, fatigue etc. Individuals can start feeling the effects at low/moderate altitude within hours and can become serious if symptoms are not managed. This occurs because at higher areas above sea level, there is a decreased partial pressure of oxygen, meaning that our bodies need to work harder to maintain a proper reserve of oxygen to sustain body functioning. 

Two popular questions are “How do I know my risk for altitude illness and prepare for higher altitudes?” It’s highly variable and even with formal testing including bloodwork and oxygen efficiency, it’s no guarantee to how one may react in higher altitudes. It’s critical to allow for ample time to acclimate, have a plan if medical attention is needed, maintain adequate nutrition and hydration and train appropriately prior to the activity (training looks different for every individual, so it’s highly advised to work with clinicians who have experience with wilderness medicine).

The findings for how females respond to altitude has a lot of variability and this is largely in part due to monthly hormonal shifts, hormonal imbalances, stress levels, medical history, body composition among other components. Below the main research findings pertaining to hormones are highlighted:

During Menstruation: Blood loss can lead to possible reduction of iron storage, which can impact oxygen levels, especially at higher altitudes. It’s important to note the amount of blood loss, the integrity of discharge (presence of clots or flow rate) and past history of premenstrual syndrome symptoms such as bloating, personality changes, pain etc. There are a few research studies that indicate that there might be a smaller likelihood of experiencing altitude illness during the luteal stage and the correlation may be due to an increase of progesterone (potential reduction in inflammation) and reduction in estrogen. 

During Pregnancy: There is a lot of debate among clinicians about the safety of engaging in altitude activities while pregnant. It greatly depends on the woman’s health history (both current and past), prior exposure to altitude, medication usage and access to medical care in a remote area. It’s advised to stay at lower altitudes, take it easier physically and be monitored as advised by the medical team. 

Body Composition: Females in general tend to have more fat deposits than males, which could impact the amount of carbohydrates required at higher altitudes and overall conditioning. The best way to determine the proper nutrient balance is through training and consulting with a dietician. 

The current research does provide insight to properly train at altitude and things to consider with the female hormonal cycle, but no two bodies are alike so it’s important to merge the findings with your current health statues. As of now, there are no major reported differences in experiencing altitude sickness between genders and very small changes observed depending on where the female is in the menstrual cycle. It’s important to remember that there is a lot of variance among the research with level of altitude, amount of time spent in altitude, the health history of test subjects and activities performed, so consider the research findings that appear most pertinent to you. 

Listen to the upcoming webinar “The Effects of Altitude and the Female Body.” to learn more about how to prepare for altitude and the latest research on the effects of altitude on the female body! 

Research Articles:

1. Custem and Pattyn. Primum non nocere; It’s Time to Consider Altitude Training as the Medical Intervention It Actually Is! Front Psychol 2022
2. Fogwe L. A., Reddy V., Mesfin F. B.  Neuroanatomy, Hippocampus . Treasure Island, Florida: StatPearls Publishing; 2022. [PubMed] [Google Scholar]
3. Ocampo A. C., Squire L. R., Clark R. E. Hippocampal area CA1 and remote memory in rats. Learning & Memory . 2017;24(11):563–568. doi: 10.1101/lm.045781.117. [PMC free article] [PubMed] [CrossRef] [Google Scholar]
4. Richalet et al. Cardiovascular Physiology and Pathophysiology at High Altitude. Natur Rev Cardiolog 2023
5. Rock et al. Women at Altitude: Effect of Menstrual-Cycle Phase on Acute Mountain Sickness During Deployment to High Altitude Terrain. US Army Institute of Environmental Medicine 2022
6. Stellingwerff et al. Nutrition and Altitude: Strategies to Enhance Adaptation, Improve Performance and Maintain Health: A Narrative Review. Sports Med. 2019; 49