Journal article
Habitual exercise training in older adults offsets the age-related prolongation in leg vasodilator kinetics during single-limb lower body exercise
Journal of applied physiology (1985), Vol.125(3), pp.746-754
09/01/2018
DOI: 10.1152/japplphysiol.00235.2018
PMCID: PMC6842877
PMID: 29856264
Abstract
We tested the hypothesis that aging is associated with prolonged leg vasodilator kinetics and habitual exercise training in older adults improves these responses relative to untrained older adults. Additionally, we examined the relationship between contraction-induced rapid onset vasodilation (ROV) and vasodilator kinetics. Young (
n
= 10), older untrained (
n
= 13), and older trained (
n
= 14) adults performed single and rhythmic knee-extension contractions at 20% and 40% work-rate maximum (WR
max
). Femoral artery diameter and mean blood velocity were measured by Doppler ultrasound. Vascular conductance (VC; ml·min
−1
·mmHg
−1
) was calculated using blood flow (ml/min) and mean arterial pressure (mmHg). The primary outcome was the kinetic response (mean response time; MRT), modeled using an exponential model, expressed as the number of duty cycles to change 63% of the steady-state amplitude. There were no age- or training-related differences in VC MRT between the groups at 20% WR
max
. Older untrained adults exhibited prolonged VC MRT at 40% WR
max
relative to young (37 ± 16 vs. 24 ± 10 duty-cycles;
P
< 0.05) and older trained adults (37 ± 16 vs. 23 ± 14 duty-cycles;
P
< 0.05). There were no differences in VC MRT between young and older trained adults at 40% WR
max
(
P
= 0.96). There were no associations between peak ROV and VC MRT at 20% or 40% WR
max
(
r
= −0.08 and 0.22;
P
= 0.67 and 0.20, respectively) in the group as a whole. Our data suggest
1
) advancing age prolongs leg vasodilator kinetics;
2
) habitual exercise training in older adults offsets this age-related prolongation; and
3
) contraction-induced ROV is not related to vasodilator kinetics within a group of young and older adults.
NEW & NOTEWORTHY
Aging is associated with reductions in exercise hyperemia and vasodilation at the onset of exercise, as well as during steady-state exercise. Habitual endurance exercise training offsets these age-related reductions. We found that aging prolongs vasodilator kinetics in the leg of older untrained but not older trained adults. Finally, our results demonstrate that contraction-induced rapid vasodilation is not associated with vasodilator kinetics within the leg of young and older adults.
Details
- Title: Subtitle
- Habitual exercise training in older adults offsets the age-related prolongation in leg vasodilator kinetics during single-limb lower body exercise
- Creators
- William E Hughes - Department of Physical Therapy and Rehabilitation Science, Carver College of MedicineNicholas T Kruse - Department of Physical Therapy and Rehabilitation Science, Carver College of MedicineKenichi Ueda - Department of Anesthesia, Carver College of MedicineDarren P Casey - Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine
- Resource Type
- Journal article
- Publication Details
- Journal of applied physiology (1985), Vol.125(3), pp.746-754
- Publisher
- American Physiological Society; Bethesda, MD
- DOI
- 10.1152/japplphysiol.00235.2018
- PMID
- 29856264
- PMCID
- PMC6842877
- ISSN
- 8750-7587
- eISSN
- 1522-1601
- Grant note
- HL-105467; T32HL-007121 / ; ;
- Alternative title
- EXERCISE TRAINING AND VASODILATOR KINETICS WITH AGE
- Language
- English
- Date published
- 09/01/2018
- Academic Unit
- Anesthesia; Physical Therapy and Rehabilitation Science; Fraternal Order of Eagles Diabetes Research Center; Internal Medicine
- Record Identifier
- 9984047645102771
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