Effet controlatéral de la négative Vs positive?

[Nutrimuscle-Conseils]

Eccentric, but not concentric blood flow restriction resistance training increases muscle strength in the untrained limb
Ethan C.Hill Physical Therapy in Sport Available online 30 January 2020


Highlights
• Eccentric-only BFR increases muscle strength in an untrained arm.
• Increased muscle activation in untrained, contralateral limb.
• Eccentric-only BFR increased muscle strength for all modes.
• Mode of training, not BFR, affects cross-education.

Objectives
Little is known regarding the variables or mechanisms mediating cross-education as a result of resistance training. Therefore, the purpose of the present study was to examine the effects of low-load eccentric-only blood flow restriction (Ecc-BFR) and low-load concentric-only BFR (Con-BFR) on indices of cross-education.

Design
Thirty-six women were randomly assigned to 4-wks of unilateral resistance training with Ecc-BFR (n = 12), Con-BFR (n = 12) or control (no intervention, n = 12) group. Eccentric peak torque, concentric peak torque, maximal voluntary isometric contraction torque, muscle thickness, and muscle activation were assessed from the contralateral, untrained arm.

Results
Muscle strength (collapsed across mode) increased from 0-wk to 2-wks (4.9%) and 4-wks (13.0%) for Ecc-BFR only. There were increases in muscle activation (collapsed across mode and group) regardless of training modality, but there were no changes in muscle size for any of the conditions.

Conclusions
The findings of the present study indicated that low-load Ecc-BFR increased muscle strength. The increases in muscle strength as a result of Ecc-BFR were not mode-specific. Thus, low-load Ecc-BFR provides a unique alternative to maintain muscle function in an untrained limb that may have application during limb immobilization and rehabilitation practices.

[RM-Coach]

Merci!
Encore une preuve de l’intérêt de s’entrainer du coté sain pour ne pas perdre en force. Ca remotive à s’entrainer quand on est blessé, d’autant plus qu’on sait que plein de pratiquants ne reprennent pas la muscu après une blessure compte tenu de la vitesse à laquelle on perd (ce qui est démotivant)

[RM-Coach]

Sur le sujet de la negative vs la positive dans l’effet controlateral

https://shareok.org/handle/11244/50800

Résumé
Traditionally, contralateral training interventions have been applied in the unilateral limb to examine the potential short-term “cross-over” responses and long-term “cross education” adaptations in the contralateral limb. Despite the completion of a multitude of studies, there is still a nescience regarding differences in training adaptations based solely upon specificity of training phase (e.g., concentric [idiot] vs. eccentric [ECC] exercise). PURPOSE: To compare the training adaptations elicited from idiot vs. ECC resistance exercise to evaluate the ipsilateral and contralateral limb’s responses and adaptations. METHODS: Twenty healthy, college-aged (18-35 years old) men (N = 10) and women (N = 10) volunteered to participate in this investigation. Participants were required to unilaterally resistance train three days per week for a total of eight weeks. Participants were randomly assigned into either idiot or ECC training groups and were asked to perform bicep curls for five sets of ten repetitions (to momentary fatigue) per training visit with their dominant limb only. Ipsilateral and contralateral limb responses and adaptations were evaluated in two week increments following the initial familiarization visit. Cross-sectional area (CSA), maximal dynamic strength, maximal isometric strength, and force fluctuations during submaximal contractions (30%, 50%, and 70% of maximal voluntary contraction [MVC]), as well as surface electromyographic (EMG) and mechanomyography (MMG) signals were collected during all evaluation visits. RESULTS: When ECC and idiot unilateral exercises are performed in isolation, ECC training causes a greater stimulus for promoting neurophysiological adaptations (e.g., greater increase in CSA, maximal dynamic and isometric strength, and a decrease in force fluctuations [e.g., greater improvement in force steadiness]) across time. Furthermore, these neurophysiological adaptations are not only greater in the trained (ipsilateral) limb, but it also appears that they are greater in the untrained (contralateral) limb through inter-limb transfer of sensorimotor adaptations. CONCLUSIONS: Our results further support the findings from previous research which indicated that ECC unilateral training was a better stimulator for contralateral responses and adaptations when compared to idiot unilateral training. Therefore, we have concluded that our results were attributed to an increase in neural drive and a decrease in corticospinal inhibition, which would cause greater cross-over responses and cross-educational adaptations due to a larger percentage of neural impulses remaining on the ipsilateral side of the body and not crossing over (at the medulla oblongata) to the contralateral side.

[Nutrimuscle-Diététique]

Un entraînement excentrique, mais non concentrique, à la restriction de la circulation sanguine augmente la force musculaire du membre non entraîné
Ethan C.Hill Physical Therapy in Sport Disponible en ligne le 30 janvier 2020


Points forts
• Le RFB excentrique uniquement augmente la force musculaire d'un bras non entraîné.
• Augmentation de l'activation musculaire dans un membre controlatéral non entraîné.
• BFR excentrique uniquement a augmenté la force musculaire pour tous les modes.
• Le mode de formation, et non le BFR, affecte la formation mixte.

Objectifs
On sait peu de choses sur les variables ou les mécanismes de médiation entre les formations résultant de l'entraînement en résistance. Par conséquent, le but de la présente étude était d'examiner les effets de la restriction du débit sanguin excentrique à faible charge (Ecc-BFR) et du BFR concentrique à faible charge (Con-BFR) sur les indices de la scolarité.

Conception
Trente-six femmes ont été assignées au hasard à 4 semaines de formation de résistance unilatérale avec Ecc-BFR (n = 12), Con-BFR (n = 12) ou groupe témoin (aucune intervention, n = 12). Le couple maximal excentrique, le couple maximal concentrique, le couple de contraction isométrique volontaire maximal, l'épaisseur musculaire et l'activation musculaire ont été évalués à partir du bras controlatéral non entraîné.

Résultats
La force musculaire (s'est effondrée à travers le mode) est passée de 0 semaine à 2 semaines (4,9%) et 4 semaines (13,0%) pour Ecc-BFR uniquement. Il y avait des augmentations de l'activation musculaire (effondré à travers le mode et le groupe) indépendamment de la modalité d'entraînement, mais il n'y avait aucun changement dans la taille musculaire pour aucune des conditions.

Conclusions
Les résultats de la présente étude ont indiqué que l'Ecc-BFR à faible charge augmentait la force musculaire. Les augmentations de la force musculaire résultant d'Ecc-BFR n'étaient pas spécifiques au mode. Ainsi, l'Ecc-BFR à faible charge offre une alternative unique pour maintenir la fonction musculaire dans un membre non entraîné qui peut avoir une application pendant les pratiques d'immobilisation et de rééducation du membre.