Do Women Need Different Carb Strategies During Their Menstrual Cycle? New Research Says Probably Not

For years, athletes and coaches have debated how the menstrual cycle affects training, recovery, and nutrition.

One common question is whether women need different carbohydrate strategies depending on where they are in their cycle.

Should you consume more carbs during the luteal phase? Less during the follicular phase? Does carbohydrate supplementation even work the same throughout the month?

A new study published in Scandinavian Journal of Medicine & Science in Sports provides some important answers.

The Relationship Between Carbohydrates and Performance

Carbohydrates are the body's preferred fuel source during moderate-to-high intensity exercise.

As exercise duration increases, muscle glycogen stores gradually become depleted. This can lead to fatigue, reduced power output, and slower performance.

For this reason, carbohydrate supplementation is one of the most widely studied and proven sports nutrition strategies available.

However, relatively little research has examined whether the effectiveness of carbohydrate supplementation changes throughout different phases of the menstrual cycle.

What Did Researchers Study?

Researchers recruited 12 recreationally trained female cyclists and examined performance during two distinct menstrual cycle phases:

• Mid-follicular phase
• Mid-luteal phase

Participants completed multiple cycling sessions consisting of:

• 90 minutes of heavy-intensity cycling
• Consumption of either a carbohydrate beverage or placebo
• A subsequent 4-kilometer cycling time trial

The researchers also measured:

• Perceived exertion
• Fatigue ratings
• Leg pain
• Neuromuscular fatigue
• Muscle function

Finding #1: Carbohydrates Improved Performance

The most important finding was clear:

Carbohydrate supplementation improved time-trial performance compared to placebo.

After completing 90 minutes of heavy cycling, athletes who consumed carbohydrates completed the 4 km time trial faster than those who consumed the placebo beverage.

This reinforces decades of sports nutrition research showing that carbohydrates remain one of the most effective performance-enhancing nutritional strategies for endurance exercise.

Finding #2: Menstrual Cycle Phase Didn't Change the Benefit

Many athletes assume they may need entirely different fueling strategies depending on their menstrual cycle phase.

However, the researchers found that the performance benefit from carbohydrate supplementation was essentially identical during both the follicular and luteal phases.

In practical terms, carbohydrates helped performance regardless of which phase of the menstrual cycle participants were in.

This suggests that female endurance athletes may not need dramatically different carbohydrate supplementation strategies between these two phases when performing prolonged high-intensity exercise.

Finding #3: Fatigue Responses Were Similar Across Phases

The researchers also examined several markers of perceived and neuromuscular fatigue.

Interestingly, they found:

• No significant differences in perceived exertion (RPE)
• No differences in ratings of fatigue
• No differences in leg pain
• No meaningful differences in maximal voluntary muscle contraction

Overall, fatigue responses appeared remarkably similar between the two menstrual cycle phases studied.

What Does This Mean for Female Athletes?

The findings provide encouraging news for active women.

While individual responses to the menstrual cycle can vary, this study suggests that carbohydrate supplementation remains an effective endurance performance strategy regardless of whether an athlete is in the mid-follicular or mid-luteal phase.

Rather than completely redesigning a fueling plan each month, athletes may benefit more from consistently meeting overall carbohydrate requirements before and during demanding training sessions.

The Importance of Proper Fueling

Many athletes focus heavily on training but underestimate the impact of nutrition.

Whether you're cycling, running, competing in endurance events, or performing high-volume training sessions, carbohydrate availability remains one of the primary factors influencing performance.

Supporting glycogen stores before training and replenishing energy afterward can help athletes maintain training quality, improve recovery, and support long-term performance goals.

Key Takeaways

• Carbohydrate supplementation improved endurance performance after prolonged heavy-intensity cycling.
• The performance benefits were similar during both the mid-follicular and mid-luteal menstrual cycle phases.
• Perceived fatigue and most fatigue-related measures did not differ significantly between phases.
• Female athletes may not need dramatically different carbohydrate supplementation strategies between these two menstrual cycle phases.
• Consistent fueling and recovery practices remain critical for long-term performance.

References

1. Fleitas-Paniagua PR, Rasica L, Azevedo RA, Alvares TS, Zagatto AM, Murias JM. Menstrual Cycle Phase Does Not Affect Carbohydrate Supplementation Ergogenic Effect After Heavy Intensity Cycling. Scandinavian Journal of Medicine & Science in Sports. 2024. DOI: 10.1111/sms.70240.
2. Jeukendrup AE. Carbohydrate intake during exercise and performance.
3. Burke LM. Fueling strategies to optimize endurance performance.