Thresholds Power Profiles Predict Performance in Youth Road Cycling

Gabriele Gallo, Luca Filipas, Michele Tornaghi, Mattia Garbin, Roberto Codella, Nicola Lovecchio, and Daniele Zaccaria

Purpose:

To analyze the anthropometric and physiological characteristics of competitive 15- to 16-year-old young male road cyclists and scale them according to a dichotomous category of successful/unsuccessful riders. Methods: A total of 103 15- to 16-year-old male road cyclists competing in the Italian national under 17 category performed a laboratory incremental exercise test during the in-season period. Age, height, body mass, body mass index, peak height velocity, and absolute and relative power output at 2 mmol/L and 4 mmol/L of blood lactate concentration were compared between 2 subgroups, including those scoring at least 1 point (successful, n = 70) and those that did not score points (unsuccessful, n = 61) in the general season ranking. Results: Successful and unsuccessful riders did not differ anthropometrically. Successful riders recorded significantly higher absolute and relative power output at 2 mmol/L and 4 mmol/L of blood lactate concentration compared with unsuccessful riders. Successful riders were also significantly older and had advanced biological maturation compared with their unsuccessful counterparts. Conclusion: Power associated with blood lactate profiles, together with chronological age and peak height velocity, plays an important role in determining race results in under 17 road cycling. Physiological tests could be helpful for coaches to measure these performance predictors.

Physiological factors such as maximal oxygen consumption and anaerobic thresholds are recognized as pivotal factors for time trial cycling performance. However, in road cycling the majority of the competitions are mass-start races, in which anaerobic reserve, bike handling skills, tactical abilities, and decision making could play an important role. In this regard, only one study correlated physiological parameters with overall race outcomes in road cycling. In this study, Menaspà et al highlighted the fact that junior Italian cyclists with the best places in the final annual national ranking were older and with superior aerobic (ie, VO2max, respiratory compensation point, peak power output) but not anaerobic (5-s maximum power output) characteristics.

To date, it is still unknown whether chronological age, level of biological maturation, anthropometric, and physiological parameters are correlated with race performance in younger age groups and, more generally, if these factors affect performance in under 17 (U17) endurance athletes. Therefore, the purpose of our study was to report the anthropometric and physiological reference values of U17 Italian cyclists and to observe whether these parameters and biological and/or chronological age can be scrutinized as an index of performance or underperformance in this specific age group. Our hypothesis was that chronological age, level of biological maturation, anthropometric, and physiological values are predictors of higher performances in U17 cyclists.

Discussion

This was the first study reporting anthropometric characteristics, level of biological maturation, and physiological characteristics of competitive national U17 cyclists. Confirming our preliminary hypothesis, the main finding was that higher absolute and relative power outputs at 2 mmol/L and 4 mmol/L are largely associated (P < .001; effect sizes = 0.79–0.85) with success in races of U17 competitive cyclists.

Menaspà et al reported similar findings, showing a correlation between superior aerobic characteristics and race results in junior cyclists. This suggests that, even if other factors such as tactics, bike handling skills, decision making, and anaerobic reserve could impact race outcomes, aerobic parameters remain crucial in determining race results in youth road cycling.

Ultimately, the authors could not ascertain whether this was related to genetic or training factors, as endurance training has been shown to reduce blood lactate accumulation at the same exercise intensity, even in a young population. Furthermore, in youth cycling categories the performance level is very heterogenous. Therefore, it remains to be determined whether these results could be extended or not to more homogeneous performance groups, such as elite athletes. In fact, in professional cyclists a correlation between aerobic characteristics and time trial results has been reported, while no studies have been conducted on mass-start races or general rankings, in which mass-start race are predominant.

As to chronological age and PHV, the authors found that successful cyclists were also older and with advanced biological maturation than their unsuccessful counterparts, although no differences in anthropometric characteristics (height, body mass, and BMI) were highlighted. This finding could suggest that success in youth categories is highly dependent on the level of maturation of the athletes, although biological age was only theoretically derived. In addition, the present study included only Italian U17 cyclists. Future research is needed in multicenter studies with cyclists from different countries.

Practical Applications

Anthropometric and physiological values of the present study could be useful for coaches in a comparison of their cyclists with successful and unsuccessful cyclists in the U17 category. In particular, absolute and relative power output at specific lactate concentrations seems to be a critical determinant of U17 performance, highlighting the importance of physiological assessments in this specific age group. In addition, the fact that chronological age and biological maturation plays a key role in the race results could induce national cycling federations to split the youth categories on an annual basis. This decision could help young athletes not to lose motivation during the first year in the age category.

Conclusion

Higher absolute and relative power output at 2 mmol/L and 4 mmol/L is largely associated with success in U17 competitive cycling races. Moreover, biological maturation is positively correlated to success in this age category.