Edinburgh Napier University

  Female participation in regular sport activities has increased in recent years, yet their representation in the sports and exercise science literature remains low. Therefore, an understanding of the effects different phases of the menstrual cycle (MC) have on exercise responses is important due to the practical and theoretical implications. The aim of this study was to compare performance, physiological and perceptual differences when performing a running repeated sprint ability (RSA) during the early-follicular (EF), and mid-luteal (ML) sub-phases of the MC. Six healthy, physically active female participants (age: 25.67 ± 2.49 years; height: 1.66 ± 0.08 m; body mass: 69.8 ± 19.3 kg; V̇O2peak: 46.00 ± 6.76 ml·kg¹·min⁻¹) took part in this study. After the initial health screening, the participants completed two familiarisation and four intervention sessions (twice during each MC sub-phase). The RSA protocol consisted of five ‘all-out’ sprints of six seconds on a non-motorised treadmill with 24 seconds of active recovery (walking) between the sprints. Results indicated no significant differences between MC sub-phases in mean (p = 0.998, d = 0.00) and peak power output (p = 0.14, d = 0.16), distance (p = 0.59, d = 0.07), pre-exercise (p = 0.78, d = 0.41) and post-exercise lactate (p = 0.58, d = 0.24), oxygen uptake (p = 0.10, d = 0.30), respiratory exchange ratio (p = 0.47, d = 0.13), ventilation (p = 0.42, d = 0.12), heart rate (p = 0.49, d = 0.17). However, significant differences were found in peak acceleration (EF: 4.65 ± 0.84 m·s⁻², ML: 5.05 ± 1.14 m·s⁻²) (p = 0.02, d = 0.40) and rating of perceived exertion (RPE) (EF: 13.42 ± 2.15, ML: 12.60 ± 2.26) (p < 0.001, d = 0.37). In conclusion, MC phases do not appear to influence most of the chosen RSA performance indicators. However, due to the low sample size and statistical power, further studies are required to better investigate the effects of the MC on RSA.