Assessment of Metabolic Flexibility by Substrate Oxidation Responses and Blood Lactate in Women Expressing Varying Levels of Aerobic Fitness and Body Fat

Copyright © 2022 National Strength and Conditioning Association..

ABSTRACT: Waldman, HS, Bryant, AR, Knight, SN, Killen, LG, Davis, BA, Robinson, MA, and O'Neal, EK. Assessment of metabolic flexibility by substrate oxidation responses and blood lactate in women expressing varying levels of aerobic fitness and body fat. J Strength Cond Res 37(3): 581-588, 2023-Collection of substrate oxidation responses during exercise is proposed as a noninvasive means for assessing metabolic flexibility in male subjects. However, because of hormonal and metabolic differences between sexes, this method may not be applicable to female subjects. This study assessed metabolic flexibility through indirect calorimetry across female subjects with different maximal oxidative capacities. Thirty-eight (18-45 years) eumenorrheic female subjects were stratified ( p < 0.05) based on V̇ o2 peak (mL·kg -1 ·min -1 ) into (1) endurance-trained (ET, n = 12, 42.6 ± 5.3), (2) recreationally active (RA, n = 13, 32.3 ± 1.6), or (3) overweight female subjects (OW, n = 13, 21.0 ± 4.0). Subjects completed the same 5-stage graded exercise test with intensities of 30, 45, 60, 75, and 90 W. Lactate [La - ], carbohydrate (CHOox), and fat (FATox) oxidation rates were assessed during the last min of each 5-minute stage. Subjects then cycled to exhaustion to determine V̇ o2 peak. Endurance-trained and RA female subjects expressed significantly ( p ≤ 0.05) higher absolute rates and rates scaled to fat-free mass of CHOox and FATox compared with OW female subjects during multiple stages. [La - ] failed to consistently differentiate the 3 groups with higher [La - ] for OW only found during stage 4; however, RER differed by 0.09 units or more at each stage for OW vs. ET. It seems that RER was more sensitive to cohort characteristics than [La - ] contrasting recent findings in male cohorts. In conclusion, indirect calorimetry is a practical and noninvasive method for assessing metabolic flexibility in eumenorrheic female subjects of varying aerobic fitness levels.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:37

Enthalten in:

Journal of strength and conditioning research - 37(2023), 3 vom: 01. März, Seite 581-588

Sprache:

Englisch

Beteiligte Personen:

Waldman, Hunter S [VerfasserIn]
Bryant, Andrea R [VerfasserIn]
Knight, Savanna N [VerfasserIn]
Killen, Lauren G [VerfasserIn]
Davis, Brett A [VerfasserIn]
Robinson, Marcus A [VerfasserIn]
O'Neal, Eric K [VerfasserIn]

Links:

Volltext

Themen:

33X04XA5AT
Journal Article
Lactic Acid

Anmerkungen:

Date Completed 27.02.2023

Date Revised 19.08.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1519/JSC.0000000000004316

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM34356601X