Priming exercise accelerates pulmonary oxygen uptake kinetics during "work-to-work" cycle exercise in middle-aged individuals with type 2 diabetes
Citation:
Gildea N, Rocha J, O'Shea D, Green S and Egaña M., Priming exercise accelerates pulmonary oxygen uptake kinetics during "work-to-work" cycle exercise in middle-aged individuals with type 2 diabetes, European Journal of Applied Physiology, 121, 2, 2021, 409 - 423Download Item:
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Abstract:
Purpose: The time constant of phase II pulmonary oxygen uptake kinetics ([Formula: see text]) is increased when high-intensity exercise is initiated from an elevated baseline (work-to-work). A high-intensity priming exercise (PE), which enhances muscle oxygen supply, does not reduce this prolonged [Formula: see text] in healthy active individuals, likely because [Formula: see text] is limited by metabolic inertia (rather than oxygen delivery) in these individuals. Since [Formula: see text] is more influenced by oxygen delivery in type 2 diabetes (T2D), this study tested the hypothesis that PE would reduce [Formula: see text] in T2D during work-to-work cycle exercise.
Methods: Nine middle-aged individuals with T2D and nine controls (ND) performed four bouts of constant-load, high-intensity work-to-work transitions, each commencing from a baseline of moderate-intensity. Two bouts were completed without PE and two were preceded by PE. The rate of muscle deoxygenation ([HHb + Mb]) and surface integrated electromyography (iEMG) were measured at the right and left vastus lateralis, respectively.
Results: Subsequent to PE, [Formula: see text] was reduced (P = 0.001) in T2D (from 59 ± 17 to 37 ± 20 s) but not (P = 0.24) in ND (44 ± 10 to 38 ± 7 s). The amplitude of the [Formula: see text] slow component ([Formula: see text]2 As) was reduced (P = 0.001) in both groups (T2D: 0.16 ± 0.09 to 0.11 ± 0.04 l/min; ND: 0.21 ± 0.13 to 0.13 ± 0.09 l/min). This was accompanied by a reduction in ΔiEMG from the onset of [Formula: see text] slow component to end-exercise in both groups (P < 0.001), while [HHb + Mb] kinetics remained unchanged.
Conclusions: PE accelerates [Formula: see text] in T2D, likely by negating the O2 delivery limitation extant in the unprimed condition, and reduces the [Formula: see text]As possibly due to changes in muscle fibre activation.
Sponsor
Grant Number
Health Research Board (HRB)
HRA_POR/2073/274
Author's Homepage:
http://people.tcd.ie/meganaDescription:
PUBLISHED
Author: Egana, Mikel
Type of material:
Journal ArticleCollections:
Series/Report no:
European Journal of Applied Physiology121
2
Availability:
Full text availableKeywords:
Near-infrared spectroscopy, Oxygen extraction, Oxygen uptake slow component, Cycling, ElectromyographySubject (TCD):
Aerobic exercise , EXERCISE TOLERANCE , Exercise Medicine , Exercise physiology , OXYGEN UPTAKE , TYPE 2 DIABETESDOI:
http://dx.doi.org/10.1007/s00421-020-04518-yLicences: