Supervisors info:
Κοσκολού Μ., Αναπληρώτρια Καθηγήτρια, ΣΕΦΑΑ, ΕΚΠΑ
Γελαδάς Ν., Καθηγητής, ΣΕΦΑΑ, ΕΚΠΑ
Τουμπέκης Α., Καθηγητής, ΣΕΦΑΑ, ΕΚΠΑ
Summary:
Exercise-induced arterial hypoxemia (EIAH) is defined as a drop of arterial blood oxygen saturation (SaO2) ≥ 3% during maximal exercise at sea level and is more apparent in highly trained individuals. This phenomenon has not been extensively studied in females, and especially in athletes of team sports. The aim of the present study is to investigate the prevalence of EIAH in female football athletes and its effect on field performance.
Thirty female football athletes performed incremental exercise on a treadmill to volitional exhaustion. Each stage lasted 2.5 min, the speed increased by 3.2 km/h per stage, until reaching a comfortable speed (9.6 or 12.8 km/h), and the gradient was increased by 2% per stage thereafter, until exhaustion. Heart rate (HR), hemoglobin oxygen saturation (SpO2), and respiratory parameters were recorded continuously, the rate of perceived exertion (RPE) at the end of each stage, and blood lactate concentration ([La]) 3 min after the cessation of the exercise. With this protocol maximal oxygen uptake (V̇O2max) and the occurrence or absence of EIAH were determined. On a different day, 11 of the athletes performed, on a football pitch, the modified Hoff test, i.e. a 10-min test with ball dribbling and movement patterns specific to the sport, where the athlete is asked to cover the longest possible distance. Total distance, maximum HR, end-exercise SpO2, RPE, and post-exercise [La] were recorded. Statistical analysis included parametric and non-parametric tests for comparing dependent and independent means, correlation (Spearman's rho), and 2-way analysis of variance (EIAH occurrence x time) for comparing the SpO2 course between athletes with and without EIAH. The level of statistical significance was set at p ≤ .05.
Half of the participants developed EIAH with a drop in SpO2 (ΔSpO2) of 9.45 ± 4.98 % from the value at rest. The athletes who developed (n = 15) and those who did not develop (n = 15) EIAH did not differ in the descriptive characteristics or in the respiratory response at maximal intensity. No correlation was found between V̇O2max and field performance. The athletes who had developed EIAH during the incremental protocol performed on the field on average (1449 ± 50.7 m) better (p = .009) than those who had not developed EIAH (1348 ± 42.8 m). However, this difference between groups cannot be associated to the EIAH development.
In conclusion, 50% of female athletes developed EIAH, whereas previous studies have reported higher prevalence of EIAH in females with higher aerobic capacity. The lack of correlation between V̇O2max and performance on the field test as well as the difference observed in the field test between the two groups might be a result of technical ability differences, which were not measured in the present study. More research is needed involving a wider range of V̇O2max to ascertain the prevalence of EIAH in female football athletes and to test whether the Hoff test is appropriate for this specific population.
Keywords:
exercise-induced arterial hypoxemia, desaturation, adults, females, athletes, exercise, football, maximal oxygen uptake
