Title

Early detection of prolonged decreases in maximal voluntary contraction force after eccentric exercise of the knee extensors

Document Type

Journal Article

Publication Title

Medicine & Science in Sports & Exercise

Volume

54

Issue

2

Publisher

Wolters Kluwer

School

School of Medical and Health Sciences / Centre for Exercise and Sports Science Research

RAS ID

40663

Comments

Ruas, C. V., Latella, C., Taylor, J. L., Haff, G. G., & Nosaka, K. (2022). Early detection of prolonged decreases in maximal voluntary contraction force after eccentric exercise of the knee extensors. Medicine & Science in Sports & Exercise, 54(2), 267-279.

https://doi.org/10.1249/MSS.0000000000002797

Abstract

Purpose

We examined whether the magnitude of muscle damage indicated by changes in maximal voluntary isometric contraction (MVIC) strength 1 to 3 d after unaccustomed eccentric exercise (ECC) was correlated with changes in central and peripheral neuromuscular parameters immediately post-ECC.

Methods

Twenty participants (19–36 yr) performed six sets of eight eccentric contractions of the knee extensors. Rate of force development (RFD) during knee extensor MVIC, twitch force, rate of force development (RFDRT) and rate of relaxation (RRRT) of the resting twitch, maximal M-wave (MMAX), voluntary activation, silent period duration, motor-evoked potentials (MEP) and short-interval intracortical inhibition were assessed before, immediately after, and 1 to 3 d post-ECC. Relationships between changes in these variables immediately post-ECC and changes in MVIC strength at 1 to 3 d post-ECC were examined by Pearson product–moment (r) or Spearman correlations.

Results

Maximal voluntary isometric contraction strength decreased (−22.2% ± 18.4%) immediately postexercise, and remained below baseline at 1 (−16.3% ± 15.2%), 2 (−14.7% ± 13.2%) and 3 d post-ECC (−8.6% ± 15.7%). Immediately post-ECC, RFD (0–30-ms: −38.3% ± 31.4%), twitch force (−45.9% ± 22.4%), RFDRT (−32.5% ± 40.7%), RRRT (−38.0% ± 39.7%), voluntary activation (−21.4% ± 16.5%) and MEP/MMAX at rest (−42.5% ± 23.3%) also decreased, whereas the silent period duration at 10%-MVIC increased by 26.0% ± 12.2% (P < 0.05). Decreases in RFD at 0 to 30 ms, 0 to 50 ms, and 0 to 100 ms immediately post-ECC were correlated (P < 0.05) with changes in MVIC strength at 1 d (r = 0.56–0.60) and 2 d post-ECC (r = 0.53–0.63). Changes in MEP/MMAX at 10%-MVIC immediately post-ECC were correlated with changes in MVIC strength at 1 d (r = −0.53) and 2 d (r = −0.54) post-ECC (P < 0.05).

Conclusions

The magnitude of decrease in MVIC strength at 1 to 3 d after ECC was associated with the magnitude of changes in RFD and MEP/MMAX immediately post-ECC. However, based on individual data, these markers were not sensitive for the practical detection of muscle damage.

DOI

10.1249/MSS.0000000000002797

Access Rights

subscription content

Research Themes

Society and Culture

Priority Areas

Human movement and performance

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