If you’re a dedicated runner aiming to increase their VO2 maximum without success, or a bodybuilder facing challenges in muscle development, or even a CrossFit devotee struggling to progress despite your best efforts, then the issue hindering your progress could surprisingly be your hormonal birth control medication.
Approximately 14 percent of individuals between 15 and 49 years old who are on the pill may have doubts about whether their oral contraceptive is thwarting their fitness aspirations. While research remains limited, recent findings suggest that it may hinder muscle growth and cardiovascular capacity.
Below, three experts in hormones and women’s health elaborate on how hormonal birth control pills can potentially influence athletic performance.
Three ways birth control pills impact physical performance
1. Could Conceal Signs of Overexertion
Alterations in your menstrual cycle or experiencing amenorrhea could indicate overtraining or insufficient nourishment for athletes and fitness enthusiasts, explains exercise physiologist Stacy Sims, CSCS, PhD.
“A natural menstrual cycle serves as a gauge of how well your body is adjusting to your training routine,” she observes. “A seamless adaptation means you won’t face any menstrual disruptions due to exercise.”
2. Might Hinder Muscle Growth
Studies have indicated that taking birth control pills could stall muscle development. A 2021 research published in the Journal of Strength and Conditioning Research revealed that oral contraceptive use may reduce muscle gains. The study, involving 72 women aged 18 to 29, compared the impact of birth control pills on resistance training outcomes. They assessed the participants’ body composition and hormone levels before and after a 10-week resistance training regimen.
The research found that individuals on birth control pills exhibited higher cortisol levels and lower concentrations of hormones like DHEA, DHEAS, and IGF-1 (essential for muscle growth) compared to those not taking the pill. Specifically, those on birth control with synthetic progesterone gained only half a pound of lean muscle mass compared to 3.5 pounds for the non-pill group over the ten weeks.
Though crucially, Dr. Sims notes that the strength gains did not differ significantly between the two groups, despite the muscle mass distinction. Nonetheless, this loss in muscle mass could be detrimental for athletes like Olympic weightlifters striving for strength without increasing weight categories.
3. May Diminish Cardiovascular Capacity
Endurance athletes, alongside strength athletes, may encounter adverse effects from oral contraceptives. Laura DeCesaris, DC, a functional medicine consultant and powerlifter, mentions that research suggests birth control pills could lead to lower VO2 max, indicating a reduced ability to utilize oxygen during training.
During intense workouts, higher oxygen intake is essential for maintaining performance levels. A lower VO2 max would thus limit the intensity and duration of your training sessions, she explains.
When Hormonal Contraceptives May Not Be Detrimental to Athletes
Dr. DeCesaris expresses, “The existing data on this topic is still somewhat inconclusive.” Many studies on the pill’s impact on performance have been relatively small, she points out. Furthermore, most research studies encompass various types of oral contraceptives instead of focusing on pills with similar hormonal compositions.
“Moreover, individual responses to oral contraceptives vary based on personal physiology,” adds Dr. DeCesaris. Some individuals might not experience any detrimental effects on their performance, while others might experience unwelcome setbacks.
In essence, making sweeping statements about the pill’s interference with athletic performance is challenging, she concludes.
Choosing the Right Birth Control for Athletes
While a hormonal contraceptive might be the suitable choice for you and your healthcare provider, Dr. Sims emphasizes that athletic performance is just one factor to weigh when selecting a contraceptive.
However, it’s crucial to acknowledge that the birth control pill isn’t the sole option available. According to Alisa Vitti, founder of FLO Living and author of Woman Code and In the FLO, alternatives include opting for a progestin-only or copper IUD.
“I often recommend the progestin-only IUD as it has minimal systemic effects, and many individuals resume natural ovulation within six to eight months, enabling cycle tracking through basal body temperature,” she mentions.
Additionally, combining ovulation tracking with barrier methods or other contraception protocols during ovulation can be effective, as ovulation is the only fertile window during your cycle, Vitti suggests.
Dr. Sims emphasizes the importance of discussing all your objectives with your provider. Rather than merely stating your desire to avoid unwanted pregnancies, share your strength and endurance targets to ensure you choose a contraceptive that aligns with all your goals and aspirations.
