Dataset Information

Effects of knee extension with different speeds of movement on muscle and cerebral oxygenation.

ABSTRACT:

Background

One of the mechanisms responsible for enhancing muscular hypertrophy is the high metabolic stress associated with a reduced muscular oxygenation occurring during exercise, which can be achieved by reducing the speed of movement. Studies have tested that lowered muscle oxygenation artificially induced by an inflatable cuff, could provoke changes in prefrontal cortex oxygenation, hence, to central fatigue. It was hypothesized that (1) exercising with a slow speed of movement would result in greater increase in cerebral and greater decrease in muscle oxygenation compared with exercises of faster speed and (2) the amount of oxygenation increase in the ipsilateral prefrontal cortex would be lower than the contralateral one.

Methods

An ISS Imagent frequency domain near infrared spectroscopy (NIRS) system was used to quantify oxygenation changes in the vastus lateralis muscle and prefrontal cortex (contra- and ipsilateral) during unilateral resistance exercises with different speeds of movement to voluntary fatigue. After one maximal repetition (1RM) test, eight subjects performed three sets of unilateral knee extensions (?50% of 1RM), separated by 2 min rest periods, following the pace of 1 s, 3 s and 5 s for both concentric and eccentric phases, in a random order, during separate sessions. The amount of change for NIRS parameters for muscle (?Hb: deoxyhemoglobin, ?HbO: oxyhemoglobin, ?HbT: total hemoglobin, ?StO₂: oxygen saturation) were quantified and compared between conditions and sets by two-way ANOVA RM. Differences in NIRS parameters between contra- and ipsilateral (lobe) prefrontal cortex and conditions were tested.

Results

Exercising with slow speed of movement was associated to larger muscle deoxygenation than normal speed of movement, as revealed by significant interaction (set × condition) for ?Hb (p = 0.01), and by significant main effects of condition for ?HbO (p = 0.007) and ?StO₂ (p = 0.016). With regards to the prefrontal cortex, contralateral lobe showed larger oxygenation increase than the ipsilateral one for ?Hb, ?HbO, ?HbT, ?StO₂ in each set (main effect of lobe: p < 0.05). Main effects of condition were significant only in set1 for all the parameters, and significant interaction lobe × condition was found only for ?Hb in set1 (p < 0.05).

Discussion

These findings provided evidence that speed of movement influences the amount of muscle oxygenation. Since the lack of oxygen in muscle is associated to increased metabolic stress, manipulating the speed of movement may be useful in planning resistance-training programs. Moreover, consistent oxygenation increases in both right and left prefrontal lobes were found, suggesting a complementary interaction between the ipsi- and contralateral prefrontal cortex, which also seems related to fatigue.

SUBMITTER: Formenti D

PROVIDER: S-EPMC6173162 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature

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Publications

Effects of knee extension with different speeds of movement on muscle and cerebral oxygenation.

Formenti Damiano D Perpetuini David D Iodice Pierpaolo P Cardone Daniela D Michielon Giovanni G Scurati Raffaele R Alberti Giampietro G Merla Arcangelo A

PeerJ 20181002

<h4>Background</h4>One of the mechanisms responsible for enhancing muscular hypertrophy is the high metabolic stress associated with a reduced muscular oxygenation occurring during exercise, which can be achieved by reducing the speed of movement. Studies have tested that lowered muscle oxygenation artificially induced by an inflatable cuff, could provoke changes in prefrontal cortex oxygenation, hence, to central fatigue. It was hypothesized that (1) exercising with a slow speed of movement wou ...[more]

PMID: 30310747

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Dataset Information

Effects of knee extension with different speeds of movement on muscle and cerebral oxygenation.

Background

Methods

Results

Discussion

Publications

Effects of knee extension with different speeds of movement on muscle and cerebral oxygenation.

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