Blood Biomarkers and Wingate Test Performance in Latvian Youth Athletes: design and pre-season assessment

OBJECTIVE: Nowadays youth athletes experience high physical workload due to increasing number of competitive matches, including participation among older age groups. Proper monitoring of youth athletes throughout the season are of importance to ensure optimal development, recovery, and injury prevention. To evaluate the health of Latvian youth athletes project within National Research Programme 'Sport' (IMRSportsLV; Nr. VPP-IZM-Sports-2023/1-0001) has been initiated. This project aims to develop research methods and guidelines for evaluation of physical and mental health of youth athletes across the season.

METHODS: Pre-season testing of 12–18-year-old athletes began in fall 2024, evaluating physical fitness (aerobic and anaerobic capacity), movement quality (Functional Movement Screen, Y-Balance Test), anthropometry (BMI, waist circumference, bioimpedance), blood biomarkers and questionnaires of burn out, well-being, and competition anxiety. This abstract focuses on some baseline measures. So far fasting blood samples have been collected from 112 athletes (48 females, 54 males; age 15.5±3.07). Anaerobic performance has been estimated using the Wingate 30-second maximal power test on a Cyclus2 veloergometer for 77 athletes (29 females and 48 males, age 15.9±1.6), who did not report bodily pain or discomfort. Follow-up assessments in mid- and end-season will be performed to track changes over time.

RESULTS: When compared to reference values pre-season assessments showed insufficient vitamin D levels in 60% of youth athletes with varied magnitude (severe: 8.55±1.91 ng/mL, n=2; moderate: 16.22±2.86 ng/mL, n=15; mild: 24.31±2.98 ng/mL, n=51). Low ferritin was observed in 13 athletes (5.78±1.3 ng/mL), while 9 had decreased hemoglobin (116.44±2.40 g/L). Elevated glucose levels were detected in 3 athletes (6.79±1.77 mmol/L). Lipid profile analysis showed low HDL in 5 athletes (0.96±0.019 mmol/L) and elevated LDL in 9 (3.28±0.22 mmol/L). Baseline testosterone-to-cortisol ratio was 0.004±0.002 in females and 0.062±0.025 in males (p<0.001). Wingate test results showed that female relative peak anaerobic power (8.35±0.93 W/kg) and relative anaerobic capacity (6.88±0.73 W/kg) was significantly lower (p<0.001) than for males (10.88±1.21 W/kg and 8.84±0.87 W/kg, respectively). There was no correlation between blood biomarkers and anaerobic performance when adjusted for sex.

CONCLUSION: Pre-season results show that notable number of athletes have low ferritin and hemoglobin levels. Furthermore, vitamin D insufficiency among youth athletes is highly prevalent. Hormonal analysis revealed sex-based differences in testosterone-to-cortisol ratios, while Wingate test results showed notable differences in anaerobic power and capacity between males and females. These findings highlight the need for continuous monitoring of youth athletes and such interventions as supplementation of vital micronutrients for optimal physical health and performance.