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The aims of the present study were to characterize the mechanical output of final road sprints of an elite sprinter during international competitions in relation to his power‐velocity‐endurance characteristics and to investigate the relationship between this sprint performance and the power produced during preceding phases of the race. The sprinter performed a set of short and long sprints (5 to 15‐s) on a cycle ergometer to determine his maximal power‐velocity‐endurance profile. Based on eleven races, the distribution of power throughout each race, peak and mean power (Ppeak and Pmean) and associated pedaling rates (vPpeak and vPmean) during the final sprint were analyzed. The power‐velocity‐endurance profile of the sprinter indicated that his theoeretical mean maximal power and corresponding optimal pedaling rate ranged from 20.0 W.kg−1 (124 rpm) for a 1‐s sprint to 15.0 W.kg−1 (109 rpm) for 20 s. Race data showed that final road sprints were mainly performed on the ascending limb of the power‐velocity relationship (vPpeak, 104 ± 8 and vPmean, 101 ± 8 rpm). Additionally, Ppeak and Pmean were lower than the theoretical maximal power determined from the power‐velocity‐endurance profile (9.9 ± 7.0% and 10.6 ± 9.8%, respectively), which highlighted a significant state of fatigue induced by the race. Finally, sprint power exhibited a high variability between races and was strongly related to the level of power produced during the last minute before the sprint. These findings show the importance of considering both the power‐velocity‐endurance qualities and the power demand of the last lead‐up phase before the sprint in order to optimize final sprint performance. [ABSTRACT FROM AUTHOR]

The article presents a controlled laboratory study carried out to determine the effects of a new treatment, localized air-pulsed cryotherapy and the recovery time-course of neuromuscular function after a strenuous eccentric exercise. The study employed of 24 participants in a control group (CONT) or a cryotherapy group (CRYO) group. It concludes that four applications of air-pulsed cryotherapy after a strenuous eccentric exercise proved to ineffective in promoting long-term muscle recovery.

The aims of this study were to determine (1) the individual tactics employed by elite modern pentathletes within each discipline of the new combined running-shooting event, and (2) the consequences of these strategies on overall performance. For 36 male pentathletes competing in a World Cup event, we measured running velocity, transition time, shooting time, shooting accuracy, and delay per shot. Performances of the top third of athletes, middle third of athletes, and the bottom third of athletes in the combined event were compared. The difference in overall performance between the top third and middle/bottom thirds was predominately associated with better shooting accuracy (79 ± 13%, 68 ± 12%, and 64 ± 10% success rate for top, middle, and bottom third, respectively) and faster shooting time (86 ± 16 s, 109 ± 19 s, and 117 ± 23 s for top, middle, and bottom third, respectively). No significant differences in running velocity, transition time or delay per shot were observed among the three groups. All the competitors started significantly faster over the first 200 m of each of the three 1-km running stages. The last third of the approximately 3-km race was completed significantly faster by all athletes (P < 0.05). The main finding was that the best performers of the combined event distinguished themselves due to their greater shooting accuracy. [ABSTRACT FROM AUTHOR]

An abstract of the article "Change of Pedaling Technique and Muscle Coordination During an Exhaustive Exercise," by Sylvain Dorel, Jean-Marc Drouet, Antoine Couturier, Yvan Champoux and François Hug is presented.

Summary: The concept of ventilatory thresholds (VTs) has been shown to be particularly useful to prescribe exercise intensities, yet, to date no study has examined the effects of previous submaximal exercise (i.e. a simulated training session) on the subsequent occurrence of VTs. We designed the present study to test the hypothesis that a previous short simulated training session induces an earlier VTs occurrence. Thirteen trained subjects perfomed two classical incremental tests on a cycle ergometer. The two tests were separated by a time period of 2–5 days, and the second test was preceded by a 34-min simulated training session. The first and second VTs (VT1 and VT2, respectively) were detected and expressed in their corresponding values of time, , and power output. The simulated training session did not modify VT1 occurrence. In contrast, VT2 was influenced by the simulated training session, showing a significant earlier occurence when VT2 was expressed in time [−42 (−72; −13)s] and in power output [−15 (−25; −5)W]. Maximal power tolerated (MPT) was also significantly reduced by the previous exercise [−17 (−27; −7)W]. As a consequence, training intensities based on power output (associated with VT2 or in %MPT) would be overestimated (i.e. higher metabolic state) after a short period of training session. Thus, doubt is cast on the pertinence of using the power output (or running speed by extension) for prescription of exercise during prolonged training sessions. [Copyright &y& Elsevier]

Purpose: The aim of this study was to evaluate concomitantly the changes in leg-spring behavior and the associated modifications in the lower limb muscular activity during a constant pace run to exhaustion at severe intensity. Methods: Twelve trained runners performed a running test at the velocity associated with VO2max (5.1±0.3ms-1; mean time to exhaustion: 353±69s). Running step spatiotemporal parameters and spring-mass stiffness were calculated from vertical and horizontal components of ground reaction force measured by a 6.60m long force platform system. The myoelectrical activity was measured by wireless surface electrodes on eight lower limb muscles Results: The leg stiffness decreased significantly (-8.9%; P<0.05) while the vertical stiffness did not change along the exhaustive exercise. Peak vertical force (-3.5%; P<0.001) and aerial time (-9.7%; P<0.001) decreased and contact time significantly increased (+4.6%; P<0.05). The myoelectrical activity decreased significantly for triceps surae but neither vastus medialis nor vastus lateralis presented significant change. Both rectus and biceps femoris increased in the early phase of swing (+14.7%; P<0.05) and during the pre-activation phase (+16.2%; P<0.05). Conclusion: The decrease in leg spring-stiffness associated with the decrease in peak vertical ground reaction force was consistent with the decline in plantarflexor activity. The biarticular rectus femoris and biceps femoris seem to play a major role in the mechanical and spatiotemporal adjustments of stride pattern with the occurrence of fatigue during such exhaustive run. [ABSTRACT FROM AUTHOR]