Contraceptive Choices for Female Athletes: Impact on Training Performance

Why Does Contraception Affect Athletic Performance?

Contraceptive methods work by altering or stabilizing hormones, which directly affects:

• Estrogen/progesterone curves
• Core body temperature
• Red blood cell production
• Ligament laxity
• Blood volume
• Mood and sleep

Comparison of Major Contraceptive Methods

Research Review on Combined Oral Contraceptives (COC)

A 2020 Meta-Analysis (Elliott-Sale et al.) reviewed 42 studies:

• VO2max decreased by an average of 5–11%
• Strength and power showed no significant differences
• Training adaptations slightly reduced (lower markers of mitochondrial biogenesis)
• Injury risk: slightly lower risk of knee ligament injuries (due to smoother estrogen fluctuations)
• Ferritin slightly increased (reduced menstrual blood loss)

Considerations for athletes: If VO2max is critical (middle- to long-distance endurance), COC may not be the first choice; however, if there is a significant injury history (recurrent ACL tears), COC can actually provide stability.

Pros and Cons of IUD-Cu (Copper IUD)

Pros:

• No hormonal interference
• Natural cycle preserved
• One insertion lasts 10 years

Cons:

• Menstrual blood loss increases by 50–100%
• Increased iron loss, significantly higher risk of iron-deficiency anemia
• Menstrual cramps may worsen
• Not suitable for athletes who already have heavy periods

Mirena IUS (Progestin IUD): A Choice for Many Endurance Athletes

• Very little progestin absorbed systemically
• 50–70% of users become amenorrheic after one year
• Iron loss greatly reduced
• Does not affect core body temperature
• Natural ovulation is preserved in most users

It is a relatively ideal choice for triathletes or marathon runners, but professional gynecological evaluation is required.

Is Amenorrhea a Good or Bad Thing?

Amenorrhea after using an IUS is a normal physiological response, which is completely different from the “amenorrhea” seen in RED-S:

Contraceptive Strategies in Season Planning

Methods to Delay Menstruation

• Continuous COC use: skip the placebo week
• Continuous use of the contraceptive patch or ring
• Short-term use of progestin medication (Norethisterone): start 3 days before the event, 3 times daily
• Test it once 6 months in advance for the first time—don’t experiment on the eve of a race

Key Points for Monitoring Side Effects

For the first 3 months of using a new contraceptive method, track:

• Training RPE, HRV
• Pace and heart rate
• Mood and sleep
• Libido and skin condition
• Body weight and water retention

If performance drops significantly for 2 consecutive months, discuss switching options with your gynecologist.

An Important Reminder

Contraception is not just a performance issue—it also involves personal health, sexual life, and life planning. Please discuss it with both a gynecologist and sports medicine professional—don’t make decisions based on the internet.

Related Reading

• Contraception and Endurance Performance: The Interaction of Combined Pills, Progestin Systems, and Exercise Physiology
• Training Differences for Female Cyclists: How the Menstrual Cycle Affects Athletic Performance
• Female Running Physiology: How Hormones Affect Endurance Performance
• Hormonal Changes in Masters Athletes: The Impact of Declining Testosterone on Training Recovery