The purpose of the present study was to examine the effect of sex and performance standard on pacing profiles in a 24 h ultra-marathon race. Performance data of 283 participants (237 men and 46 women) from the last decade’s versions (2011 until 2020, with the exception of the 2017 version) of the International Ultramarathon Festival held in Athens-Hellinikon, Greece, were analyzed and pacing profiles were evaluated based on performance standard and sex. Relative speed for every hour and % distance covered in 6 h and 12 h segments and coefficient of variation (CV) were calculated. Mean distance ran was 159.99±36.04 km. Runners followed a reverse J-shaped race pace ( p < 0.001). Sex did not seem to interact with pacing ( p > 0.05 in every case), while performance standard interacted significantly with pacing ( p < 0.001). CV was negatively correlated with total distance covered and total running time (–0.761, p < 0.001 and –0.753, p < 0.001, respectively). In conclusion, the overall pacing profile adopted by runners in a 24 h ultra-marathon race was a reverse J-shaped model, with better runners following a more even pacing than slower runners, with lower velocity variability.

Background/Objectives: This study aimed to examine the post-activation performance enhancement effects of bilateral horizontal drop jumps (BHDJs) on 30 m sprint and countermovement jump (CMJ) performance, as well as in sprint mechanical and kinematics characteristics. Methods: Fourteen young sprinters (nine boys and five girls) completed both an experimental condition (EC) and a control condition (CC). The EC consisted of five BHDJs performed at each participant’s individually determined optimal drop height, whereas in the CC, no exercise has been performed. Results: The findings revealed no significant (p > 0.05) interactions for CMJ and time to 30 m. Significant increases in 5 m split times were observed across all segments in the CC, as well as in the initial 5 m segment in the EC. Regarding sprint mechanics, a significant interaction was found in the effectiveness of horizontal force application (−2.42% in CC vs. −0.33% in EC). Step frequency demonstrated significant interaction in the 5–10 m segment (−1.79% in CC vs. 1.20% in EC) and decreased significantly in the 15–20 m segment in the CC (−2.03% in CC vs. −1.85% in EC). Conclusions: In conclusion, performance parameters reduced under the CC, whereas the BHDJ intervention stabilized these parameters or exhibited smaller performance variations than in the CC.

Objectives: The purpose of the present study was to examine the acute effects on hematological, inflammatory, cellular, muscular, myocardial, liver, biliary, and humoral immunity biomarkers during and after a 12-h track ultra-marathon event. Methods: Twelve healthy male ultra-marathon runners completed the race and all measurements, including venous blood sampling performed before the race (PRE), at 6 h during the race (MID), and immediately after finishing (POST). Results: White blood cells, neutrophils, monocytes, basophils, and platelets increased at 6 h (MID) and remained elevated after the finish (POST), while eosinophils and lymphocytes decreased at mid-race and remained suppressed until post-race. The immunoglobulin G and C-reactive protein increased post-race compared to pre- and mid-race values, while lactate dehydrogenase and interleukin-6 increased at mid-race, with no further change until post-race. Creatine kinase, creatine kinase-MB, high-sensitivity cardiac troponin I, aspartate aminotransferase, and alanine aminotransferase significantly increased mid-race and showed a further significant increase post-race. Significant correlations were found between total distance covered and the percentage of PRE-MID difference of interleukin-6 and the percentage of PRE-POST difference of interleukin-6 and lactate dehydrogenase. Conclusions: The results of the present study indicate that participation in a 12-h track ultra-marathon is associated with marked exercise-induced alterations in multiple hematological and biochemical biomarkers, with several responses already evident at mid-race (6 h).

Although pacing strategies and performance predictors have been extensively investigated in ultra-marathon running events, the 12-h ultra-marathon remains relatively understudied. The aim of the present study was to investigate the pacing profiles during a 12-h ultra-marathon event and to develop a predictive model of performance based on aerobic and anthropometric laboratory measures. Fifteen experienced male ultra-marathon runners completed an incremental treadmill test to exhaustion and subsequently participated in a 12-h track ultra-marathon race. Participants adopted a reverse J-shaped pacing strategy. Although no significant interaction between performance level and mean hourly running velocity was observed, high-level runners exhibited significantly lower velocity variability (CV). Furthermore, the predictive model demonstrated that body fat percentage, BMI, VT and HRmax were strong predictors of 12-h ultra marathon performance, showing a high explanatory capacity when combined. In conclusion, these findings highlight the combined importance of body composition, aerobic capacity and pacing regulation in optimizing performance during time-limited ultra-marathon events.