The Influence of Competition Day Loads on the Metabolic and Immune Response of Olympic Female Beach Volleyball Athletes: A Sportomics Analysis.

Background

Beach volleyball (BVb) is a highly demanding Olympic sport characterized by intense physical activity and unique environmental challenges, including varying weather conditions and sandy, unstable court surfaces. Despite its popularity, there is a notable lack of scientific research addressing the metabolic and immune responses of elite female athletes in this sport. This study aims to address this gap by investigating two world-class Olympic medalists, female BVb players, who represent a country with a rich history in the sport.

Methods

Two athletes underwent a simulated competition day consisting of two matches. A standardized protocol was utilized to collect blood and urine samples at seven time points, allowing for analysis throughout the competition and recovery phases. The analysis included various electrolytes, as well as hematological, metabolic, and inflammatory markers. Additionally, we assessed selected hormones, such as insulin, serotonin, ACTH, and cortisol, along with amino acids related to energy metabolism and neurotransmitter synthesis.

Results

Both athletes presented a trend toward electrolyte disturbances, especially hypokalemia, with a mean decrease of 15% and individual values reaching as low as 3.3 mmol/L post-match. This indicates that BVb may pose a risk for such disturbances. Additionally, the matches led to 20% to 60% increases in muscle injury markers, with incomplete recovery even after a day of rest, signaling persistent physiological stress post-competition. This increase was matched by stimulating stress hormones (ACTH and cortisol rose up to 4-fold and 3-fold, respectively), and markers of exercise intensity, such as lactate and ammonium. Moreover, the simulated BVb competition day impacted the amino acid response, with the Fischer ratio (BCAA/AAA) and blood tryptophan decreasing to a minimum of 60% of the initial levels and blood serotonin increasing by up to 180%, which are signs of an increased risk of central fatigue onset, according to the Fischer and Newsholme theory.

Conclusions

The responses examined in this exploratory study contribute to a deeper understanding of the metabolic and immune demands placed on elite female BVb players, suggesting practical applications. By addressing the similar physiological responses observed among the athletes and emphasizing their unique individual responses-despite following the same protocol under identical conditions and sharing similar life habits for an extended period-this study highlights the critical necessity for the n-of-1 monitoring of athletes.