Exercise on-transient gas exchange kinetics are slowed as a function of age

Babcock, Mark A.; Paterson, Donald H.; Cunningham, David A.; Dickinson, John R.

doi:10.1249/00005768-199404000-00007

Cited by 108 publications

(141 citation statements)

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“…During the recovery from plantar flexion exercise, it has been shown that PCr kinetics are slower in older compared with younger individuals (McCully et al 1991;McCully, Fielding, Evans, Leigh & Posner, 1993). These values are similar to the longer kinetics for VO2 adjustment to cycling exercise observed in older individuals (Babcock, Paterson, Cunningham & Dickinson, 1994b;Chilibeck, Paterson, Petrella & Cunningham, 1996a). Others have failed to find slower PCr recovery kinetics with ageing (Taylor, Crowe, Bore, Styles, Arnold & Radda, 1984).…”

Section: Introductionmentioning

confidence: 76%

The effects of age on kinetics of oxygen uptake and phosphocreatine in humans during exercise

Chilibeck¹,

Paterson²,

McCreary³

et al. 1998

Experimental Physiology

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Section: Introductionmentioning

confidence: 76%

The effects of age on kinetics of oxygen uptake and phosphocreatine in humans during exercise

Chilibeck¹,

Paterson²,

McCreary³

et al. 1998

Experimental Physiology

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“…These positive effects have been attributed, in part, to inorganic nitrate (NO 3 Ϫ ), which is particularly rich in leafy greens and beetroot. The NO 3 Ϫ anion itself is inert, and any biological effects are likely to be the result of its conversion to the nitrite anion (NO 2 Ϫ ) in the mouth via facultative anaerobic bacteria on the surface of the tongue (25). When swallowed, NO 2 Ϫ can be further converted into nitric oxide (NO) (9), but it is clear that some NO 2 Ϫ enters the circulation.…”

mentioning

confidence: 99%

“…Moreover, dietary NO 3 Ϫ supplementation may have positive effects upon the physiological response to exercise (5,50). Supplementation with NaNO 3 Ϫ (0.1 mmol·kg Ϫ1 ·day Ϫ1 ; Ref.…”

mentioning

confidence: 99%

“…Given the positive association between NO and vascular health (34), these agingrelated perturbations to NO metabolism might contribute toward the endothelial dysfunction (46,52) and arterial hypertension (26) that develop with old age. Therefore, it is feasible that dietary NO 3 Ϫ supplementation might enhance NO bioavailability and vascular function in older adults.…”

mentioning

confidence: 99%

“…Moreover, the distribution of blood flow in the microcirculation, capillary density, and capillary hemodynamics (7,8,18,30,59,60,65), as well as mitochondrial volume density and oxidative function (15,16) are compromised with aging. There is evidence that V O 2 kinetics in the transition from a lower to a higher metabolic rate is slowed in older compared with younger adults (3,14,22) and that this may be related to a limitation in muscle O 2 delivery (66). The reduction in maximal oxidative phosphorylation capacity in aged muscle (15,16,28) might also contribute toward the slower V O 2 kinetics.…”

mentioning

confidence: 99%

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Effects of short-term dietary nitrate supplementation on blood pressure, O₂uptake kinetics, and muscle and cognitive function in older adults

Kelly

Fulford

Vanhatalo

et al. 2013

American Journal of Physiology-Regulatory, Integrative and Comp

203

206

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AM. Effects of shortterm dietary nitrate supplementation on blood pressure, O 2 uptake kinetics, and muscle and cognitive function in older adults. Am J Physiol Regul Integr Comp Physiol 304: R73-R83, 2013. First published November 21, 2012 doi:10.1152/ajpregu.00406.2012 Ϫ ) supplementation has been shown to reduce resting blood pressure and alter the physiological response to exercise in young adults. We investigated whether these effects might also be evident in older adults. In a double-blind, randomized, crossover study, 12 healthy, older (60 -70 yr) adults supplemented their diet for 3 days with either nitrate-rich concentrated beetroot juice (BR; 2 ϫ 70 ml/day, ϳ9.6 mmol/day NO 3 Ϫ ) or a nitrate-depleted beetroot juice placebo (PL; 2 ϫ 70 ml/day, ϳ0.01 mmol/day NO 3 Ϫ ). Before and after the intervention periods, resting blood pressure and plasma [nitrite] were measured, and subjects completed a battery of physiological and cognitive tests. Nitrate supplementation significantly increased plasma [nitrite] and reduced resting systolic (BR: 115 Ϯ 9 vs. PL: 120 Ϯ 6 mmHg; P Ͻ 0.05) and diastolic (BR: 70 Ϯ 5 vs. PL: 73 Ϯ 5 mmHg; P Ͻ 0.05) blood pressure. Nitrate supplementation resulted in a speeding of the V O2 mean response time (BR: 25 Ϯ 7 vs. PL: 28 Ϯ 7 s; P Ͻ 0.05) in the transition from standing rest to treadmill walking, although in contrast to our hypothesis, the O 2 cost of exercise remained unchanged. Functional capacity (6-min walk test), the muscle metabolic response to low-intensity exercise, brain metabolite concentrations, and cognitive function were also not altered. Dietary nitrate supplementation reduced resting blood pressure and improved V O2 kinetics during treadmill walking in healthy older adults but did not improve walking or cognitive performance. These results may have implications for the enhancement of cardiovascular health in older age.nitrate; nitrite; nitric oxide; blood pressure; exercise performance; cognitive performance; O2 uptake kinetics THE BENEFICIAL EFFECTS OF a vegetable-rich diet upon cardiovascular health (27) and longevity (79) have been well described. These positive effects have been attributed, in part, to inorganic nitrate (NO 3 Ϫ ), which is particularly rich in leafy greens and beetroot. The NO 3 Ϫ anion itself is inert, and any biological effects are likely to be the result of its conversion to the nitrite anion (NO 2 Ϫ ) in the mouth via facultative anaerobic bacteria on the surface of the tongue (25). When swallowed, NO 2 Ϫ can be further converted into nitric oxide (NO) (9), but it is clear that some NO 2 Ϫ enters the circulation. The subsequent reduction of NO 2 Ϫ to NO and other reactive nitrogen intermediates is facilitated in hypoxia (11). The production of NO via nitric oxide synthase (NOS) is impaired in hypoxia and, thus, it has been proposed that the NO 3 Ϫ -NO 2 Ϫ -NO pathway represents a complementary system for NO generation across a wide range of redox states (53). NO is an essential physiological signaling molecule with numerous functions in...

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Exercise: Kinetic Considerations for Gas Exchange

Rossiter

2010

Comprehensive Physiology

167

255

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The activities of daily living typically occur at metabolic rates below the maximum rate of aerobic energy production. Such activity is characteristic of the nonsteady state, where energy demands, and consequential physiological responses, are in constant flux. The dynamics of the integrated physiological processes during these activities determine the degree to which exercise can be supported through rates of O₂ utilization and CO₂ clearance appropriate for their demands and, as such, provide a physiological framework for the notion of exercise intensity. The rate at which O₂ exchange responds to meet the changing energy demands of exercise--its kinetics--is dependent on the ability of the pulmonary, circulatory, and muscle bioenergetic systems to respond appropriately. Slow response kinetics in pulmonary O₂ uptake predispose toward a greater necessity for substrate-level energy supply, processes that are limited in their capacity, challenge system homeostasis and hence contribute to exercise intolerance. This review provides a physiological systems perspective of pulmonary gas exchange kinetics: from an integrative view on the control of muscle oxygen consumption kinetics to the dissociation of cellular respiration from its pulmonary expression by the circulatory dynamics and the gas capacitance of the lungs, blood, and tissues. The intensity dependence of gas exchange kinetics is discussed in relation to constant, intermittent, and ramped work rate changes. The influence of heterogeneity in the kinetic matching of O₂ delivery to utilization is presented in reference to exercise tolerance in endurance-trained athletes, the elderly, and patients with chronic heart or lung disease.

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Exercise on-transient gas exchange kinetics are slowed as a function of age

Cited by 108 publications

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The effects of age on kinetics of oxygen uptake and phosphocreatine in humans during exercise

The effects of age on kinetics of oxygen uptake and phosphocreatine in humans during exercise

Effects of short-term dietary nitrate supplementation on blood pressure, O₂uptake kinetics, and muscle and cognitive function in older adults

Exercise: Kinetic Considerations for Gas Exchange

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Exercise on-transient gas exchange kinetics are slowed as a function of age

Cited by 108 publications

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The effects of age on kinetics of oxygen uptake and phosphocreatine in humans during exercise

The effects of age on kinetics of oxygen uptake and phosphocreatine in humans during exercise

Effects of short-term dietary nitrate supplementation on blood pressure, O2uptake kinetics, and muscle and cognitive function in older adults

Exercise: Kinetic Considerations for Gas Exchange

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Effects of short-term dietary nitrate supplementation on blood pressure, O₂uptake kinetics, and muscle and cognitive function in older adults