Durability: importance in competition success across different age-related road cycling categories and training strategies to improve it.

Introduction: In addition to maximal oxygen consumption, lactate threshold and efficiency, durability has been recently shown to be an additional parameter determining long duration endurance sports performance. The influence of durability on success in different road cycling age-categories is yet to known. Furthermore, effective training strategies to improve durability have not been explored. Therefore, the aims of this thesis are (i) to understand the impact of durability on success in Junior (JUN), Under 23 (U23) and Professional (PRO) road cycling categories and (ii) to investigate effective training strategies to improve durability. Study 1: This study aimed to investigate cross sectional differences in race demands between junior, under 23 and professional road cycling categories. Race data collected during the 2019 season of thirty male road cyclists (10 for each category) were retrospectively analysed for race characteristics, external, and internal competition load. JUN races were shorter and included less elevation gain per distance unit compared to U23 and PRO races, but more internally demanding. JUN produced lower record powers output in the moderate-, heavy-, and severe-intensity exercise domains compared with U23 and PRO. U23 and PRO races presented similar work demands per hour and record power outputs, but PRO races were longer than U23. Study 2: This study investigated the field-derived power performance parameters associate with competition success in road cycling climbing specialists of different age-related categories. Training and racing data of fifty-three male climbers participated in this study (junior [JUN], n = 15; under 23 [U23], n = 21; professional [PRO], n = 17) collected during the 2016-19 competitive seasons were retrospectively analysed for record power outputs (RPOs) and RPOs after prior accumulated work to evaluate durability. For each category, cyclists were classified as high-ranked or low-ranked based on the placement in the final season general ranking of their category. Superior absolute and relative RPOs at rested state characterize high-ranked vs low-ranked JUN climbing specialists. Superior durability 6 characterized high-ranked U23 and PRO climbers compared with their low-ranked counterpart, as well as PRO versus U23 climbers high-ranked climbers. Study 3: This investigation examined cross sectional difference in training characteristics between JUN, U23 and PRO male road cyclists. Training data collected during the 2019 competitive season of thirty male cyclists, ten for each age-related categories (JUN; U23; PRO), were retrospectively analysed for training characteristics, external and internal training load. JUN spent more training time at medium and high heart rate intensity zones compared to U23 and PRO. Higher duration per training session were observed in PRO compared to both U23 and JUN. Elevation gain per distance was higher in PRO compared to U23 and JUN, and in U23 compared to JUN. Study 4: This study described the day-by-day training and racing characteristics in preparation to Giro d'Italia of one world class road cyclist who achieved a place on the podium in the final general classification of the Giro d’Italia. Daily load, daily volume and intensity distribution derived from power meter training and racing data of the 152 days leading up to the podium in the Giro d'Italia final general classification were reported. During training, a pattern alternating ‘hard days’ versus ‘easy days’ was observed, as significant amounts of medium or high intensity or load were not performed for more than two consecutive days. This pattern was achieved combining high volume (> 4 hrs) with significant amount of medium and high intensity within the same training sessions. Study 5: This study investigated if performing high-intensity training (HIT) at the end of long low-intensity training sessions enhances durability. Twenty trained cyclists were randomly allocated to one of two four-week training interventions (CON, n=10 and INT, n=10). INT performed HIT at the end of long low-intensity sessions, while CON performed HIT and long low-intensity sessions on separate days. Weekly training was matched for overall volume and time in zones. An incremental test to determine the first and second ventilatory thresholds, and 7 a 5-min time trial, was performed in a rested state and after 2.5-h cycling pre- and post-intervention. The data revealed some distinct differences in adaptations to physiological variables depending on the timing of HIT. Specifically, performing HIT in standalone short-duration sessions tended to favor adaptations in the rested state, while performing HIT at the end of long low intensity trainings sessions tended to favor adaptations after 2.5 hours of low-intensity cycling. These results indicate that the timing of HIT has an impact on durability-related adaptations in trained cyclists. Conclusions: This thesis suggests as durability is a factor determining competition results in U23 and PRO but not JUN road cycling category. Successful PRO road cyclists have superior durability compared to successful U23 and JUN cyclists, therefore young riders stepping up to the professional category should develop durability. Regarding this, this thesis also suggests as performing high-intensity training at the end of long low-intensity training sessions could be an effective training strategy to improve durability.