Skip to main content
Kent Academic Repository

Reproducibility of NIRS-derived mitochondrial oxidative capacity in highly active older adults

Fennell, Christopher R. J., Mauger, Alexis, Hopker, James G. (2023) Reproducibility of NIRS-derived mitochondrial oxidative capacity in highly active older adults. Experimental Gerontology, 175 . Article Number 112156. ISSN 0531-5565. E-ISSN 1873-6815. (doi:10.1016/j.exger.2023.112156) (KAR id:100642)

Abstract

Introduction

In-vivo techniques using near-infrared spectroscopy (NIRS) have been developed to assess skeletal muscle mitochondrial oxidative capacity. However, the test-retest and day-to-day reliability of NIRS-derived mitochondrial oxidative capacity has yet to be established in older individuals. Therefore, the primary aim of this study was to determine the day-to-day and test-retest reliability of NIRS-derived mitochondrial oxidative capacity in older adults. The secondary aim was to examine the relationship between NIRS-derived mitochondrial capacity and whole-body aerobic fitness.

Material and methods

Twenty-four healthy individuals (19 M, 5F; aged 60 ± 4 years; maximal oxygen uptake (V̇O2peak) = 41.2 ± 6.8 ml.kg−1.min−1) completed three visits to the laboratory. Visit one assessed isometric maximal voluntary contractions of the knee extensors and aerobic capacity through an incremental exercise test. In visits two and three participants completed two measurements of NIRS-derived mitochondrial oxidative capacity in the vastus lateralis (VL).

Results

NIRS-derived mitochondrial oxidative capacity was found to have good to excellent day-to-day reliability (Day 1 vs Day 2; coefficient of variation (CV) = 7.0 %; standard error of measurement (SEM) = 5.2; intra-class correlation coefficient (ICC) = 0.94) and test re-test reliability (Day 1 [Test 1 vs Test 2]; CV = 5.0 %; SEM = 3.7; ICC 0.97 and Day 2 [Test 1 vs Test 2]; CV = 6.3 %; SEM = 4.9; ICC = 0.93). NIRS-derived mitochondrial oxidative capacity was found to be significantly correlated with V̇O2peak (r = −0.61; R2 = 0.37; P = 0.002), oxygen uptake at the gas exchange threshold (r = −0.49; R2 = 0.24; P = 0.02), and oxygen uptake at the respiratory compensation point (r = −0.57; R2 = 0.32; P = 0.004).

Conclusion

NIRS provides a reliable method for deriving a measure of VL mitochondrial oxidative capacity in highly active older adults and demonstrates a significant relationship with measures of whole-body aerobic fitness.

Item Type: Article
DOI/Identification number: 10.1016/j.exger.2023.112156
Uncontrolled keywords: reproducibility; ageing; near-infrared spectroscopy; aerobic fitness
Subjects: R Medicine > RC Internal medicine > RC1200 Sports medicine
Divisions: Divisions > Division of Natural Sciences > Sport and Exercise Sciences
Funders: University of Kent (https://ror.org/00xkeyj56)
Depositing User: James Hopker
Date Deposited: 27 Mar 2023 15:53 UTC
Last Modified: 28 Mar 2024 00:00 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/100642 (The current URI for this page, for reference purposes)

University of Kent Author Information

Fennell, Christopher R. J..

Creator's ORCID:
CReDIT Contributor Roles:

Mauger, Alexis.

Creator's ORCID: https://orcid.org/0000-0001-6685-5800
CReDIT Contributor Roles:

Hopker, James G..

Creator's ORCID: https://orcid.org/0000-0002-4786-7037
CReDIT Contributor Roles:
  • Depositors only (login required):

Total unique views for this document in KAR since July 2020. For more details click on the image.