Sympathetic activity is not a main cause of blood pressure reduction with exercise training in un-medicated middle-aged/older men.
Scand J Med Sci Sports
; 33(5): 586-596, 2023 May.
Article
em En
| MEDLINE
| ID: mdl-36587373
ABSTRACT
BACKGROUND:
This study tested the hypothesis that training reduces resting sympathetic activity and improves baroreflex control in both hypertensive and normotensive men but reduces blood pressure only in hypertensive men.METHODS:
Middle-aged/older un-medicated stage-1 hypertensive males (mean age 55 ± 3 years; n = 13) and normotensive controls (mean age 60 ± 5 years; n = 12) participated in 8 weeks of supervised high-intensity interval spinning training. Before and after training, muscle sympathetic nerve activity (MSNA) and blood pressure were measured at rest and during a sympatho-excitatory cold pressor test (CPT). Based on the measurements, baroreceptor sensitivity and baroreceptor threshold were calculated.RESULTS:
Resting MSNA and baroreceptor sensitivity were similar for the hypertensive and the normotensive groups. Training lowered MSNA (p < 0.05), expressed as burst frequency (burst/min), overall, and to a similar extent, in both groups (17% and 27%, respectively, in hypertensive and normotensive group), whereas blood pressure was only significantly (p < 0.05) lowered (by 4 mmHg in both systolic and diastolic pressure) in the hypertensive group. Training did not (p > 0.05) alter the MSNA or blood pressure response to CPT or increase baroreceptor sensitivity but reduced (p < 0.05) the baroreceptor threshold with a main effect for both groups. Training adherence and intensity were similar in both groups yet absolute maximal oxygen uptake increased by 15% in the normotensive group only.CONCLUSION:
The dissociation between the training induced changes in resting MSNA, lack of change in baroreflex sensitivity and the change in blood pressure, suggests that MSNA is not a main cause of the blood pressure reduction with exercise training in un-medicated middle-aged/older men.Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Músculo Esquelético
/
Hipertensão
Limite:
Aged
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Humans
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Male
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Middle aged
Idioma:
En
Ano de publicação:
2023
Tipo de documento:
Article