Influence of affective stimuli on leg power output and associated neuromuscular parameters during repeated high intensity cycling exercises

The aim of this study was to examine the impact of emotional eliciting pictures on neuromuscular performance during repetitive supramaximal cycling exercises (RSE). In a randomized order, twelve male participants were asked to perform five 6-s cycle sprints (interspaced by 24 s of recovery) on a cycle ergometer in front of neutral, pleasant or unpleasant pictures. During each RSE, mean power output (MPO) and electromyographic activity [root mean square (RMS) and median frequency (MF)] of the vastus lateralis and vastus medialis muscles were analyzed. Neuromuscular efficiency (NME) was calculated as the ratio of MPO to RMS. Higher RMS (232.17 ± 1.17 vs . 201.90 ± 0.47 μV) and MF (68.56 ± 1.78 vs . 64.18 ± 2.17 Hz) were obtained in pleasant compared to unpleasant conditions (p < 0.05). This emotional effect persisted from the first to the last sprint. Higher MPO was obtained in pleasant than in unpleasant conditions (690.65 ± 38.23 vs . 656.73 ± 35.95 W, p < 0.05). However, this emotional effect on MPO was observed only for the two first sprints. NME decreased from the third sprint (p < 0.05), which indicated the occurrence of peripheral fatigue after the two first sprints. These results suggested that, compared with unpleasant pictures, pleasant ones increased the neuromuscular performance during RSE. Moreover, the disappearance of the beneficial effect of pleasant emotion on mechanical output from the third sprint appears to be due to peripheral fatigue

Etude de la relation détente verticale puissance maximale sur ergocycle (effets de l ethnicité)

La présente thèse a pour objectif d étudier les effets de l origine ethnique sur la relation entre la détente verticale (VJ) et la puissance maximale (Pmax) sur ergocycle. L étude A montrait que, pour une même Pmax des membres inférieurs sur ergocyle, les sujets d origine ouest-africaine (WAE) avaient une VJ supérieure à celle de sujets d origines caucasiennes (CE). L hypothèse d une inaptitude des sujets WAE aux exercices de pédalage n a pas été confirmée par l étude A qui montrait que Pmax du groupe WAE n était pas inférieure à celles du groupe CE. Le manque de pratique des exercices de pédalage chez WAE, parfois invoquée, dans la littérature n était pas vérifiée dans l étude B sur la reproductibilité de VJ et Pmax qui montrait l absence d effet d apprentissage pour WAE et CE. Le facteur socio-économique ne peut être à l origine de la différence inter-ethnique de la relation VJ-Pmax. En effet, la même différence de cette relation était observée pour des exercices de manivellage, pour lesquels il est difficile d invoquer une moindre pratique chez les sujets WAE. L hypothèse de différences de raideur musculo-tendineuse expliquant les différences inter-ethniques en VJ a été testée dans l étude C qui montrait que la relation couple-raideur différait en fonction du niveau de performance de VJ et de l origine ethnique. Enfin, nous avons profité des mesures de raideurs effectuées chez des sujets ayant réalisé des exercices maximaux de pédalage pour étudier la relation entre raideur et Pmax (étude D). Cette dernière étude a montré une corrélation significative entre la raideur musculo-tendineuse du triceps surae et la valeur de Pmax, sans effet de l origine ethnique.The purpose of the present thesis was to study the effects of the ethnic origins upon the relationship between vertical jump (VJ) and maximal power (Pmax) on a cycle ergometre. Study A showed that the mean value of VJ was higher in subjects with West-African origins (WAE) when compared with Caucasian subjects (CE). For a given value of Pmax, VJ was higher in WAE. The hypothesis of a low aptitude for cycling exercises in WAE has not been verified in study A which showed that Pmax was not lower in WAE when compared to CE. The lack of cycling practice often suggested in the literature was not confirmed by the results of a reliability study of VJ and Pmax which showed no training effect in WAE as well as CE. A socio-economical factor cannot explain the inter-ethnic difference in the relationship between Pmax and VJ. Indeed, the same difference in the Pmax-VJ relationship was observed for exercises performed with the arms (cranking exercises), for which a lower practice cannot be evoked for WAE. The hypothesis of differences in musculo-tendinous stiffness as an explanation of inter-ethnic differences in vertical jump was tested in study C which showed that the torque-stiffness depended on the level of VJ performance and the ethnic origins. Finally, we took advantage of the measurement of stiffness in subjects who performed maximal cycling exercise to study the relationship between stiffness and Pmax (study D). This last study showed a significant correlation between the musculo-tendinous stiffness of the triceps surae and Pmax, without an ethnic effect.NANTERRE-BU PARIS10 (920502102) / SudocSudocFranceF

Maximal power output and associated electromyographic activity depend on affective stimuli during repeated cycling sprints

International audienc

Reliability of Force-Velocity Tests in Cycling and Cranking Exercises in Men and Women

The present study examined the reliability of the force-velocity relationship during cycling and arm cranking exercises in active males and females. Twenty male and seventeen female physical education students performed three-session tests with legs and three-session tests with arms on a friction-loaded ergometer on six different sessions in a randomized order. The reliability of maximal power , maximal pedal rate , and maximal force were studied using the coefficient of variation (CV), the intraclass correlation coefficient (ICC) and the test-retest correlation coefficient . Reliability indices were better for men (1.74 ≤q CV ≤q 4.36, 0.82 ≤q ICC ≤q 0.97, and 0.81 ≤q ≤q 0.97) compared with women (2.34 ≤q CV ≤q 7.04, 0.44 ≤q ICC ≤q 0.98, and 0.44 ≤q ≤q 0.98) and in cycling exercise (1.74 ≤q CV ≤q 3.85, 0.88 ≤q ICC ≤q 0.98, and 0.90 ≤q ≤q 0.98) compared with arm exercise (2.37 ≤q CV ≤q 7.04, 0.44 ≤q ICC ≤q 0.95, and 0.44 ≤q ≤q 0.95). Furthermore, the reliability indices were high for and whatever the expression of the results (raw data or data related to body dimensions). and could be used in longitudinal physical fitness investigations. However, further studies are needed to judge reliability

Musculotendinous Stiffness of Triceps Surae, Maximal Rate of Force Development, and Vertical Jump Performance

The relationships between ankle plantar flexor musculotendinous stiffness (MTS) and performance in a countermovement vertical jump (CMJ) and maximal rate of torque development (MRTD) were studied in 27 active men. MTS was studied by means of quick releases at 20 (S0.2), 40 (S0.4), 60 (S0.6), and 80% (S0.8) of maximal voluntary torque (TMVC). CMJ was not correlated with strength indices but was positively correlated with MRTD/BM, S0.4/BM. The slope α2 and intercept β2 of the torque-stiffness relationships from 40 to 80% TMVC were correlated negatively (α2) and positively (β2) with CMJ. The different stiffness indices were not correlated with MRTD. The prediction of CMJ was improved by the introduction of MRTD in multiple regressions between CMJ and stiffness. CMJ was also negatively correlated with indices of curvature of the torque-stiffness relationship. The subjects were subdivided in 3 groups in function of CMJ (groups H, M, and L for high, medium, and low performers, resp.). There was a downward curvature of the torque-stiffness relationship at high torques in group H or M and the torque-stiffness regression was linear in group L only. These results suggested that torque-stiffness relationships with a plateau at high torques are more frequent in the best jumpers

Affective load controls the regulation of maximal power during a repetitive sprint ability test on a cycle ergometre

International audienc

Effects of Load on Wingate Test Performances and Reliability

International audienc

Effects of Ethnicity on the Relationship between Vertical Jump and Maximal Power on a Cycle Ergometer

The aim of this study was to verify the impact of ethnicity on the maximal power-vertical jump relationship. Thirty-one healthy males, sixteen Caucasian (age: 26.3 ± 3.5 years; body height: 179.1 ± 5.5 cm; body mass: 78.1 ± 9.8 kg) and fifteen Afro-Caribbean (age: 24.4 ±2.6 years; body height: 178.9 ± 5.5 cm; body mass: 77.1 ± 10.3 kg) completed three sessions during which vertical jump height and maximal power of lower limbs were measured. The results showed that the values of vertical jump height and maximal power were higher for Afro-Caribbean participants (62.92 ± 6.7 cm and 14.70 ± 1.75 W•kg-1) than for Caucasian ones (52.92 ± 4.4 cm and 12.75 ± 1.36 W•kg-1). Moreover, very high reliability indices were obtained on vertical jump (e.g. 0.95 < ICC < 0.98) and maximal power performance (e.g. 0.75 < ICC < 0.97). However, multiple linear regression analysis showed that, for a given value of maximal power, the Afro-Caribbean participants jumped 8 cm higher than the Caucasians. Together, these results confirmed that ethnicity impacted the maximal power-vertical jump relationship over three sessions. In the current context of cultural diversity, the use of vertical jump performance as a predictor of muscular power should be considered with caution when dealing with populations of different ethnic origins

Effects of emotional stimuli on power output and associated surface EMG activity during repeated sprints on cycle ergometer

International audienc