Less than 4% of participants in studies of carbohydrate-based fueling strategies for soccer performance have been female: results from an audit of her representation

A summary of the research:

Women's soccer has grown significantly in popularity and professionalism, making it crucial for players to have proper nutrition, especially regarding carbohydrate (CHO) intake, to perform at their best. However, this study aimed to investigate whether the scientific information guiding these carbohydrate recommendations for soccer players is actually based on research involving female athletes. The researchers searched seven different scientific databases for studies that looked at the effects of acute (short-term) carbohydrate strategies before or during soccer performance. They found 43 relevant studies in total.

The audit revealed a significant gap in the research: out of 542 total participants across all studies, only 3.7% (20 individuals) were female, while 96.3% (522 individuals) were male. Most of the studies (95.3%) focused solely on male athletes, with only one study exclusively on females and one with a mixed group of males and females. Importantly, neither of the studies that included female participants provided any details about their menstrual cycle status. This means that the current guidelines for carbohydrate fueling in soccer are largely based on male data, and it's currently unknown if they are truly optimal for female players, especially given the known biological differences between sexes.

Here are three key practical takeaways for women's soccer coaches and administrators:

• Understand the Limited Evidence Base for Female Players: The research shows that less than 4% of participants in studies forming carbohydrate fueling guidelines for soccer were female. This means that almost all existing dietary recommendations you might be using are based on male physiology and performance. Therefore, coaches and administrators should recognize that these guidelines might not be perfectly optimal or fully applicable to their female athletes, potentially limiting performance gains or even increasing risks if not carefully considered.

• Recognize the Lack of Menstrual Cycle Consideration: Of the very few studies that included female participants, none provided information about the athletes' menstrual cycle status. Since there are known physiological and metabolic differences that can occur across the menstrual cycle phases, this omission means that current carbohydrate fueling guidelines don't account for these potential variations. Coaches should be aware of this significant gap, which suggests that a "one-size-fits-all" approach to nutrition for female players might not be effective across different phases of their cycle.

• Consider Potential Sex-Based Differences in Carbohydrate Metabolism: The sources highlight that males and females can differ in how they use fuel during exercise, with females potentially relying more on fatty acids during prolonged exercise and exhibiting different muscle glycogen utilization patterns than males during soccer match-play. Additionally, observational studies suggest female players often consume lower daily carbohydrate amounts than recommended. Coaches and team nutritionists should not simply apply male-derived recommendations without considering these potential underlying physiological differences, and should instead look for ways to individualize nutrition strategies where possible, acknowledging that female-specific research is still evolving.

Authors: Laura McManus, Vinicius S. Faria, Michael Scriney & Brendan Egan

You can read the entire article here.