The role of maturity offset in predicting aerobic and anaerobic performance outcomes in young off-road cyclists

Introduction: Biological maturation is a crucial aspect when assessing performance in young athletes. The maturity offset, indicating the time relative to Peak High Velocity (PHV), can impact aerobic and anaerobic capacity, as well as absolute and relative power outputs. This study investigated how maturity offset affects Peak Power Output (PPO) during the power-cadence test and Maximum Power Achieved (MPA) during an incremental ramp test in young off-road cyclists. Methods: Twenty-two young off-road cyclists (15 m, 7f) were recruited. The maturity offset of each participant was calculated using the Mirwald's predictive equations for boys and girls. A bike fitting was performed on their own bikes installed on a specific bike roller to optimize joint function. Before testing, participants were asked to warm-up for 10 min at self-selected pedalling intensity and cadence. Then, they performed a power-cadence test which consisted of five maximum sprints, each lasting 6 s, using different gear ratios. Later, participants were asked to perform an incremental ramp test with an initial power output of 2.8 W*kg-1, increasing by 10 W*min-1 until exhaustion. Nevertheless, maturity offset did not appear to be a significant predictor of cyclists' relative power-to-weight ratio. Conclusion: Maturity offset appears to be a strong predictor of absolute PPO and MPA rather than relative PPO and MPA. This suggests that maturity status mainly affects aerobic and anaerobic absolute power. However, early mature status is not necessarily associated with higher performances compared to peers with late mature status. The use of maturity offset can be an effective technique for contextualizing performance in youth, as well as for monitoring the biological developmental trajectories of young athletes.