Aaron Agudo-Ortega

We investigated the acute physiological responses to circuit strength training performed with different work-to-rest interval durations (10:10, 20:20, and 30:30 s) under a constant 1:1 ratio. Thirty-four trained adults (15 males and 19 females) completed a 14-min circuit protocol consisting of two blocks of 6-min separated by a 2-min rest period. Each session included six alternating upper- and lower-body exercises performed at maximal intended velocity. Heart rate (HR) was continuously monitored during the protocol, while blood lactate concentration, countermovement jump (CMJ) height, and 10-m sprint performance were assessed pre-, mid-, and post-circuit session. Repeated-measures ANOVA was used for CMJ height, blood lactate concentration and 10-m sprint performance, and one-way ANOVA for HR data. The 30:30 protocol elicited the highest post-exercise lactate concentrations (p < 0.05) and the largest decrements in CMJ height. In contrast, HR was consistently higher in the 10:10 protocol across several time points (p < 0.01), indicating greater cardiovascular demand. Sprint performance declined from pre- to post-exercise across all protocols, indicating a time-dependent fatigue response. These findings demonstrate that manipulating absolute work-to-rest durations, even under a fixed 1:1 ratio, produces distinct physiological responses, while performance decrements may occur independently of protocol configuration. Longer intervals (30:30) maximize metabolic stress and neuromuscular fatigue, whereas shorter intervals (10:10) enhance cardiovascular load. The 20:20 protocol represents a balanced alternative between both stimuli.

Hyrox© is a hybrid competition that is gaining prominence in the competitive field due to its physical demanding nature and broad appeal to athletes from various backgrounds. Understanding athlete profiles and performance determinants in these events is essential to optimize training and recovery strategies. Objectives: This study aimed to examine and describe the profile of athletes participating in Hyrox© competitions, focusing on variables related to their sports background, training habits, recovery strategies, physical capacities, and motivational aspects. Methods: A descriptive analysis was conducted using an ad hoc questionnaire fulfilled by 80 active Hyrox© athletes. The questionnaire addressed aspects such as training frequency and structure, previous athletic experience, strength and endurance levels, recovery practices, and personal goals. Results: The findings revealed a predominantly male athlete profile with high physical demands and prior experience in functional or endurance-based sports. Participants generally exhibited well-developed strength and endurance capacities. However, recovery strategies were often unstructured or insufficient, potentially compromising performance and increasing injury risk. Conclusions: Athletes competing in Hyrox© share characteristics with those in other high-intensity or hybrid modalities, including strong aerobic and anaerobic capacities. Nonetheless, a gap remains in the implementation of structured recovery protocols. These results highlight the need to incorporate comprehensive recovery strategies alongside physical preparation to optimize performance and athlete longevity in hybrid events.

This study aimed to analyse the placebo effect associated with caffeine on the performance of sprinters in a 60-meter sprint test and a standing triple jump. Methods: Thirteen trained sprinters (7 men, 6 women) volunteered to complete the experimental procedures (22.8 ± 4.7 years, 64.7 ± 6.5 kg and 173.9 ± 6.5 cm). A repeated, randomized, and counterbalanced experimental design was used to compare the effects of the ingestion of a placebo reported as caffeine (placebo) and a control situation where no substance was ingested (control). In both conditions, they completed a standing triple jump, and a 60-meter sprint test and filled out a questionnaire about potential side effects. Results: Performance was similar in placebo and control conditions in the 60-meter sprint test (7.52 ± 0.46 vs. 7.55 ± 0.43 s; p = .49; small d = 0.20) and the standing triple jump (7.28 ± 0.84 vs. 7.28 ± 0.87 m; p = .95; trivial d = 0.02). The most frequent side effects derived from deceptive caffeine ingestion were increased activeness (53.8%), nervousness (23.1%) and insomnia (15.4%). Conclusion: Deceptive caffeine ingestion did not alter performance in sprint and triple jump performance in trained athletes, while some minor side effects appeared. Individual responses to placebo ingestion should be carefully considered before making recommendations for sprint athletes.

Purpose : To describe how high-level European sprint coaches (from 100 to 400 m) work to improve important factors associated with the quality of the holistic training process and the quality of the specific training session. Methods : A descriptive analysis was conducted using questionnaires from 31 European elite sprint coaches (ie, training athletes defined as tiers 3, 4, and 5) who participated voluntarily. Results : The coaches used traditional periodization (45%) with a 10- to 15-day tapering phase (48%) that includes a reduction in volume, maintenance of intensity, and focus on correct technical execution. In the 3 mesophases, coaches prioritized the basic development of strength and sprint work in the first phases of the season and emphasized more sprint-specific work in the competitive phase. Before sessions, adjustments were made based on factors such as psychological (77%), technical (48%), and physical (39%) parameters. In-session load management relies on a combination of objective and subjective measures (55%), in which the dialogue with athletes (65%) was regarded as the main resource. Feedback during and after sessions covers technical (54%), psychological (48%), and physical (35%) aspects. Recovery protocols after sessions mainly involve rest and professional guidance (42%). For performance assessment and testing, coaches utilize countermovement jump (52%), force–velocity profile (45%), and 30-m flying (61%) as main tools. Conclusions : European sprint coaches demonstrated a comprehensive approach to planning and management, shedding light on the multifaceted nature of their training methodologies and the diverse tools employed for athlete testing and monitoring.

The purpose of this study was to provide percentile curves, peak performance age for all sprint distances, and two linear regression models in order to analyse the individual trajectories of Spanish sprinters to explain the achievement of the senior category. A retrospective analysis was undertaken using rankings of the Spanish Athletics Federation. We analysed 4398 sprint athletes between 2004 and 2021. Our results show that the percentile curves are farther apart as the distance increased. Peak performance age was reached earlier in males than females in all distance categories (25.31 ± 0.12 and 25.79 ± 0.70 years for 100 m, 25.45 ± 0.16 and 27.40 ± 0.31 years for 200 m, and 25.61 ± 0.24 and 27.46 ± 2.28 years for 400 m in males and females, respectively). The two linear regressions display the importance of consistent high performance in junior categories (p < 0.01; β = −1.92 and p = 0.15; β = −1.22, respectively) together with the best results in the U23 category (p < 0.001; β = 0.51 and p < 0.001; β = 0.51, respectively) to achieve participation in the senior category. We conclude that as the running distance increases, the differences between percentiles also increase, the peak performance age occurs earlier in Spanish sprinters than shown in previous research for all sprint distances, and attaining the senior category depends upon achieving the best results in previous categories and gaining extensive experience (consistent high-performance participation) in the event.

Purpose: Monitoring performance athletes’ training responses can be efficiently completed at competitive events. This study aimed to explore the changes in swimming, countermovement-jump (CMJ), and pull-up (PU) performance following training across a competitive phase, as well as immediately before and after each race. Methods: Fourteen well-trained male sprint/middle-distance swimmers (height 179 [7] cm, mass 70 [8] kg, age 18 [2] y), from 3 regional training groups, completed CMJ and PU tests before and after the national competitions in October and May, when race performance was also assessed. Results: Swimming race performance was significantly improved from before the national competitions in October to after the national competitions in May (1.8% [3.2%], P = .044, d = 0.60, moderate effect). Although there were no significant changes in PU velocity, CMJ performance significantly improved from before the national competitions in October to after the national competitions in May (mean difference 2.29 cm, P = .004, d = 3.52) and showed before-to-after race decreases (mean difference −1.64 cm, P = .04, d = 2.28). Conclusion: Swimming performance and CMJ performance improved as the season progressed, although these improvements were not directly correlated. PU performance did not appear to be sensitive to training or race-induced fatigue, in contrast to CMJ, in this group of male swimmers.

The aim of the study was to describe the relationship between success in junior categories and success in the senior category, in sprint events. An observational and longitudinal analysis was carried out using the rankings of the Royal Spanish Athletics Federation database. We analysed 547 sprinters (238 women and 309 men) from their U14 to their senior stage who ranked in top-20 on at least one occasion during the period 2004 to 2021. The first entry in top-20 occurs mostly in U14 (44.4%, 243), and the frequency is progressively lower: 26.7% (146) in U16; 20.8% (114) in U18; 5.1% (28) in U20; 2% (11) in U23; and 0.9% (5) in senior. A similar tendency was observed in male and female athletes. Only 3,8% (9) of top-20 U14 athletes reached the senior elite, increasing this percentage in subsequent categories: 7.4% (15) in U16; 10.6% (24) in U18; 20.9% (32) in U20; and 31.4% (32) from U23 to senior. Data from female athletes showed higher maintenance of top-20 status from early categories to senior age. We conclude that even though the first entry into the national top-20 in sprint events occurs early in most cases, success in these initial stages is not a prerequisite for reaching top-20 positions in the senior category.

Evaluating force–velocity characteristics on dry-land is of the utmost importance in swimming, because higher levels of these bio-motor abilities positively affect in-water performance. However, the wide range of possible technical specializations presents an opportunity for a more categorized approach that has yet to be seized. Therefore, the aim of this study was to identify feasible differences in maximum force–velocity exertion based on swimmers’ stroke and distance specialization. To this scope, 96 young male swimmers competing at the regional level were divided into 12 groups, one for each stroke (butterfly, backstroke, breaststroke, and front crawl) and distance (50 m, 100 m, and 200 m). They performed two single pull-up tests, 5-min before and after competing in a federal swimming race. We assessed force (N) and velocity (m/s) exertion via linear encoder. There were no significant differences between pre-post maximum force–velocity exertions, despite the decreasing trend. Force-parameters highly correlated with each other and with the swimming performance time. Moreover, both force (t = −3.60, p < 0.001) and velocity (t = −3.90, p < 0.001) were significant predictors of swimming race time. Sprinters (both 50 m and 100 m) of all strokes could exert significantly higher force–velocity compared to 200 m swimmers (e.g., 0.96 ± 0.06 m/s performed by sprinters vs. 0.66 ± 0.03 m/s performed by 200 m swimmers). Moreover, breaststroke sprinters presented significantly lower force–velocity compared to sprinters specialized in the other strokes (e.g., 1047.83 ± 61.33 N performed by breaststroke sprinters vs. 1263.62 ± 161.23 N performed by butterfly sprinters). This study could provide the foundation for future research regarding the role of stroke and distance specializations in modeling swimmers’ force–velocity abilities, thus influencing paramount elements for specific training and improvement towards competitions.