Priming exercise accelerates pulmonary oxygen uptake kinetics during "work-to-work" cycle exercise in middle-aged individuals with type 2 diabetes.
Eur J Appl Physiol
; 121(2): 409-423, 2021 Feb.
Article
en En
| MEDLINE
| ID: mdl-33084929
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.Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Oxígeno
/
Ciclismo
/
Ejercicio Físico
/
Diabetes Mellitus Tipo 2
/
Pulmón
Límite:
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
Eur J Appl Physiol
Asunto de la revista:
FISIOLOGIA
Año:
2021
Tipo del documento:
Article
País de afiliación:
Irlanda