The metabolic cost of breathing for exercise ventilations: effects of age and sex.
J Appl Physiol (1985)
; 137(2): 329-342, 2024 Aug 01.
Article
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| MEDLINE
| ID: mdl-38841757
ABSTRACT
Given that there are both sex-based structural differences in the respiratory system and age-associated declines in pulmonary function, the purpose of this study was to assess the effects of age and sex on the metabolic cost of breathing (VÌo2RM) for exercise ventilations in healthy younger and older males and females. Forty healthy participants (10 young males 24 ± 3 yr; 10 young females 24 ± 3 yr; 10 older males 63 ± 3 yr, 10 older females 63 ± 6 yr) mimicked their exercise breathing patterns (voluntary hyperpnea) in the absence of exercise across a range of exercise intensities. At peak exercise, VÌo2RM represented a significantly greater fraction of peak oxygen consumption (VÌo2peak) in young females, 12.7 ± 4.0%, compared with young males, 10.7 ± 3.0% (P = 0.027), whereas VÌo2RM represented 13.5 ± 2.3% of VÌo2peak in older females and 13.2 ± 3.3% in older males. At relative ventilations, there was a main effect of age, with older males consuming a significantly greater fraction of VÌo2RM (6.6 ± 1.9%) than the younger males (4.4 ± 1.3%; P = 0.012), and older females consuming a significantly greater fraction of VÌo2RM (6.9 ± 2.5%) than the younger females (5.1 ± 1.4%; P = 0.004) at 65% VÌemax. Furthermore, both younger and older males had significantly better respiratory muscle efficiency than their female counterparts at peak exercise (P = 0.011; P = 0.015). Similarly, younger participants were significantly more efficient than older participants (6.5 ± 1.5% vs. 5.5 ± 2.0%; P = 0.001). Normal age-related changes in respiratory function, in addition to sex-based differences in airway anatomy, appear to influence the ventilatory responses and the cost incurred to breathe during exercise.NEW & NOTEWORTHY Here we show that at moderate and high-intensity exercise, older individuals incur a higher cost to breathe than their younger counterparts. However, as individuals age, the sex difference in the cost of breathing narrows. Collectively, our findings suggest that the normative age-related changes in respiratory structure and function, and sex differences in airway anatomy, appear to influence the ventilatory responses to exercise and the oxygen cost to breathe.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Consumo de Oxígeno
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Respiración
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Ejercicio Físico
Límite:
Adult
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Aged
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
J Appl Physiol (1985)
Asunto de la revista:
FISIOLOGIA
Año:
2024
Tipo del documento:
Article
País de afiliación:
Canadá