Abstract
Pre‐fatiguing Isometric Quadriceps Exercise Impairs Contralateral Quadriceps W’ During All‐out and Not Target Torque Time to Task Failure Exercise
The FASEB journal, Vol.36(S1)
05/2022
DOI: 10.1096/fasebj.2022.36.S1.R3661
PMID: 35556404
Abstract
Abstract only
Purpose
A crossover effect of pre-fatiguing dynamic quadriceps contractions, between contralateral legs, was recently documented, evidencing a centrally mediated negative impact on performance, assessed by time to task failure (TTF) at a target intensity. This has since been reproduced, however, whether a crossover effect exists during isometric exercise, which permits exercise in a restricted space for a more intricate assessment of muscle function, for example, by magnetic resonance imaging (MRI), has not been determined. Therefore, this study interrogated the crossover effect of isometric pre-fatiguing quadriceps exercise with the hypothesis that a crossover would impair TTF during isometric exercise.
Methods
Eight healthy participants (5M/3F) performed all-out isometric exercise tests (60 maximal voluntary contractions, 3 s contraction, 2 s relaxation) to determine the impulse above end test torque (W′) and critical torque (CT) to establish a target torque that invoked a TTF between 8-15 min, as defined by the torque-duration relationship (TTF = W’/(target torque – CT)). Once established, target torque TTF and all-out exercise CT and W’ were measured with and without pre-fatiguing all-out quadriceps exercise in the contralateral leg to assess the crossover effect.
Results
TTF averaged 9.8 ± 0.4 min and, interestingly, was not altered by pre-fatigue in the contralateral leg (11.9 ± 1.0 min, p = 0.34). CT was not different in control vs. pre-fatigue (73 ± 8 vs. 76 ± 10 N*m, p= 0.34) but W′, an indicator of exercise capacity, was reduced by 25% (6200 ± 1200 vs. 4700 ± 900 N*m*s, p = 0.02).
Conclusions
These data document a crossover effect of pre-fatiguing isometric quadriceps exercise on subsequent contralateral quadriceps isometric exercise, but only during all-out exercise and not target torque TTF. Furthermore, as a consequence of the unique experimental approach, utilizing a dual-leg isometric ergometer designed to fit in a MRI, the negative impact of contralateral limb pre-fatigue (e.g. increased afferent feedback) on W′ has been documented for the first time.
Details
- Title: Subtitle
- Pre‐fatiguing Isometric Quadriceps Exercise Impairs Contralateral Quadriceps W’ During All‐out and Not Target Torque Time to Task Failure Exercise
- Creators
- Matthew T. Lewis - University of UtahRyan M. Broxterman - University of UtahJesse C. Craig - University of UtahJoshua C. Weavil - University of UtahFabio G. Laginestra - University of VeronaCatherine L. Jarrett - University of UtahKanokwan Bunsawat - University of UtahMarkus Amann - University of UtahRussell S. Richardson - University of Utah
- Resource Type
- Abstract
- Publication Details
- The FASEB journal, Vol.36(S1)
- DOI
- 10.1096/fasebj.2022.36.S1.R3661
- PMID
- 35556404
- NLM abbreviation
- FASEB J
- ISSN
- 0892-6638
- eISSN
- 1530-6860
- Publisher
- WILEY
- Grant note
- National Heart, Lung, and Blood Institute: HL-103786, HL-116579, HL142603, HL-125756, HL-091830 Ruth L. Kirschstein National Research Service Award T32: HL 139451 Merit: I01 CX001999, E6910-R, E1697-R, E1572-P, E3207-R Spire: I21RX001572, E1433-P Veterans Affairs Rehabilitation Research and Development: E9275-L National Heart Lung and Blood Institute: R01HL116579
This study was supported by National Heart, Lung, and Blood Institute Grants (HL-103786, HL-116579, HL142603, HL-125756, and HL-091830); a Ruth L. Kirschstein National Research Service Award T32 (HL 139451); Merit (I01 CX001999, E6910-R, E1697-R, E1572-P, and E3207-R), Spire (I21RX001572, E1433-P), Advanced Fellowship in Geriatrics and Senior Research Career Scientist (E9275-L) Awards from the Veterans Affairs Rehabilitation Research and Development.
- Language
- English
- Date published
- 05/2022
- Academic Unit
- Health, Sport, and Human Physiology
- Record Identifier
- 9984958628502771
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