Endurance training and maximal oxygen consumption with ageing: Role of maximal cardiac output and oxygen extraction

Montero, David; Díaz-Cañestro, Candela

doi:10.1177/2047487315617118

Cited by 61 publications

(99 citation statements)

References 55 publications

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“…Although a-vO 2diff may improve with aerobic training [49, 50], the cellular mechanisms contributing to oxygen extraction within skeletal muscle also increase at a predictable rate during incremental to maximal exercise. Recent meta-analyses by Montero et al [51] and Montero and Diaz-Canestro [52] examined the effects of aerobic training on a-vO 2diff in untrained or moderately trained healthy young (<40 years old), middle-aged, and/or older (≥40 years old) individuals. These studies concluded that the improvements in VO 2 max from 5 to 52 weeks of endurance training were due to linear improvements in Q max but not a-vO 2diff .…”

Section: Applications Of the Fick Equationmentioning

confidence: 99%

Graded Exercise Testing Protocols for the Determination of VO₂max: Historical Perspectives, Progress, and Future Considerations

Beltz

Gibson

Janot

et al. 2016

Journal of Sports Medicine

235

183

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Graded exercise testing (GXT) is the most widely used assessment to examine the dynamic relationship between exercise and integrated physiological systems. The information from GXT can be applied across the spectrum of sport performance, occupational safety screening, research, and clinical diagnostics. The suitability of GXT to determine a valid maximal oxygen consumption (VO2max) has been under investigation for decades. Although a set of recommended criteria exists to verify attainment of VO2max, the methods that originally established these criteria have been scrutinized. Many studies do not apply identical criteria or fail to consider individual variability in physiological responses. As an alternative to using traditional criteria, recent research efforts have been directed toward using a supramaximal verification protocol performed after a GXT to confirm attainment of VO2max. Furthermore, the emergence of self-paced protocols has provided a simple, yet reliable approach to designing and administering GXT. In order to develop a standardized GXT protocol, additional research should further examine the utility of self-paced protocols used in conjunction with verification protocols to elicit and confirm attainment of VO2max.

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Section: Applications Of the Fick Equationmentioning

confidence: 99%

Graded Exercise Testing Protocols for the Determination of VO₂max: Historical Perspectives, Progress, and Future Considerations

Beltz

Gibson

Janot

et al. 2016

Journal of Sports Medicine

235

183

View full text Add to dashboard Cite

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“…These results are in keeping with previous findings by the same group obtained in young healthy individuals. 2 Since ET is one of the most impactful interventions in CV prevention, it seems relevant to put the present findings in the most appropriate perspective.…”

mentioning

confidence: 96%

“…Alessandro Mezzani 1 and Marco Guazzi 2 In the present issue of the European Journal of Preventive Cardiology, Montero and Dı´az-Can˜estro address a basic argument in exercise physiology, namely the cardiovascular (CV) determinants of endurance training (ET)-induced increases in VO 2max . 1 Using a meta-analytic approach, the authors provide collective evidence that changes in VO 2max after an ET period in elderly healthy subjects are linearly related to those in cardiac output reached at maximal exercise (Q max ), but not to those in arterio-venous O 2 concentration differences (Ca-vO 2max ), making a solid point on what should be the CV target of ET programs.…”

mentioning

confidence: 99%

Balancing the evidence on the cardiovascular determinants of oxygen uptake improvement after endurance training in the elderly: What are the next steps?

Mezzani

Guazzi

2015

Eur J Prev Cardiolog

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In the present issue of the European Journal of Preventive Cardiology, Montero and Dı´az-Can˜estro address a basic argument in exercise physiology, namely the cardiovascular (CV) determinants of endurance training (ET)-induced increases in VO 2max .1 Using a meta-analytic approach, the authors provide collective evidence that changes in VO 2max after an ET period in elderly healthy subjects are linearly related to those in cardiac output reached at maximal exercise (Q max ), but not to those in arterio-venous O 2 concentration differences (Ca-vO 2max ), making a solid point on what should be the CV target of ET programs. These results are in keeping with previous findings by the same group obtained in young healthy individuals.2 Since ET is one of the most impactful interventions in CV prevention, it seems relevant to put the present findings in the most appropriate perspective.Present findings are actually consistent with the body of evidence indicating O 2 delivery to skeletal muscle as the main limiting factor of peak aerobic performance during exercise, involving more than 50% of total muscle mass, such as running and cycling. This evidence has been elegantly proved in laboratory investigations comparing VO 2max , Q max and Ca-vO 2max during single-leg (knee extension) vs. two-leg (cycling) exercise in normal subjects.3,4 Such an experimental design allows the determination of the functional reserve of the peripheral links of the O 2 transport and utilization chain when freed from the O 2 delivery constraints imposed by large muscle mass use. During oneleg exercise involving around 2-3 kg of muscle, leg blood flow per unit of muscle mass is much higher (up to 2.5 L/kg/min) than that observed during twoleg exercise. The existence of a flow reserve during exercise involving a small muscle mass parallels the finding of VO 2max values as high as 250-600 mL/kg/min in human quadriceps during the same exercise model. 3,4 In addition, evidence has been put forth that muscle mitochondrial oxidative capacity at peak two-leg exercise exceeds maximal O 2 delivery in humans. 5 Overall, these findings demonstrate the existence of a large metabolic reserve, virtually excluding the possibility that the metabolic aerobic machinery of skeletal muscle is the limiting factor of peak aerobic performance. Another possible limiting factor to VO 2max is peripheral O 2 diffusing capacity, but in this regard, the available evidence is less clear. Analogously to leg blood flow and metabolic capacity, Ca-vO 2max has been found to be higher during one-leg than two-leg exercise, 6,7 but it must be acknowledged that CavO 2max is affected not only by diffusive O 2 transport, but also by O 2 delivery to the site of diffusion from skeletal muscle capillaries to mitochondria. Available data regarding diffusional O 2 conductance (which is solely a consequence of diffusive O 2 movement) in one-leg as compared to two-leg exercise in normal subjects are scarce and not conclusive. 8 On the other hand, the concept of a finite limit to cardiac outpu...

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“…[23][24][25] In contrast, VO 2peak is a linear function of variables underlying convective O 2 delivery such as maximal heart rate or stroke volume in HFpEF, [5][6][7][8][9] concurring with the predominant central limitation of VO 2peak in sedentary individuals. 4 It yet remains unresolved whether SM divergences from the healthy phenotype (primarily) determine EI in HFpEF patients.…”

mentioning

confidence: 99%

Reduced arteriovenous oxygen difference in heart failure with preserved ejection fraction patients: Is the muscle oxidative phenotype certainly involved?

Montero

Lundby

2017

Eur J Prev Cardiolog

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Heart failure (HF) is intrinsically associated with impaired functional exercise capacity, leading to substantial morbidity and mortality. 1 Understanding the aetiology and pathophysiology of exercise intolerance (EI) in HF remains essential for the advent of novel therapies, particularly concerning $50% of patients presenting with HF with preserved ejection fraction (HFpEF), for whom no effective treatment has been found thus far. 2 Peak oxygen (O 2 ) consumption (VO 2peak ), as elicited by incremental dynamic exercise involving >50% of total muscle mass (treadmill, cycle ergometer), is considered a hallmark of exercise tolerance with high prognostic value. 3 Theoretically, the impairment of any step of the O 2 transport and utilisation chain could explain the limitation of VO 2peak in HFpEF. An exhaustive scrutiny of the determinants of VO 2peak is necessary to ascertain which mechanisms should be primarily targeted for therapy. VO 2peak in healthy humans is mainly determined by convective O 2 delivery, which is a function of peak cardiac output (Q peak ) and arterial O 2 content, conforming to the Fick principle. 4Regarding HFpEF patients, markedly low VO 2peak levels are consistently associated with diminished Q peak and subsequent inability to deliver sufficient O 2 to cope with increased metabolic demands. 5-9 Moreover, anaemia, as diagnosed by haemoglobin (Hb) concentration affects !43% of HFpEF patients. 10 Decreased total circulating red blood cell volume (RBCV) is observed in nine out of 10 HFpEF patients with Hb-based anaemia, 11 hence presenting with a deficit in total blood O 2 carrying capacity. Along with cardiac and haematological factors, a peripheral limitation in the form of reduced peak a-vO 2diff is also apparent in a fraction of HFpEF studies. 7-9 Importantly, reduced peak a-vO 2diff has been portrayed as the dominant feature underlying EI in HFpEF 8,9 with anomalies in skeletal muscle (SM) morphology and function as primary culprits. 12 Furthermore, in recent exercise training (ET) guidelines for HF, it has been posited that local (knee extensor) exercise primarily targeting SM adaptations might be more effective to improve VO 2peak than wellestablished aerobic ET involving large SM mass (e.g. walking, cycling). 13 Given the relevance of the 'peripheral' paradigm for future ET prescription in HFpEF patients, we would like to ponder current evidence on the basis of sound integrative physiology with the attempt to facilitate a forthcoming robust understanding of EI in HFpEF.Peak a-vO 2diff is commonly seen as a proxy of the capacity of SM to extract (and metabolise) O 2 from the circulation. Variables facilitating O 2 diffusion from capillary into SM fibres and O 2 utilisation such as capillarisation and mitochondrial volume density (Mito VD ) are frequently deemed to determine peak a-vO 2diff . 7,8 Support or refutation of this construct can be derived from classic experimental models delving into muscle physiology. 14 For instance, substantial decreases in SM capillarisation, Mito VD and ox...

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Endurance training and maximal oxygen consumption with ageing: Role of maximal cardiac output and oxygen extraction

Abstract: The improvement in VO2max following endurance training is a linear function of Qmax, but not Ca-vO2max, through healthy ageing.

Cited by 61 publications

References 55 publications

Graded Exercise Testing Protocols for the Determination of VO₂max: Historical Perspectives, Progress, and Future Considerations

Graded Exercise Testing Protocols for the Determination of VO₂max: Historical Perspectives, Progress, and Future Considerations

Balancing the evidence on the cardiovascular determinants of oxygen uptake improvement after endurance training in the elderly: What are the next steps?

Reduced arteriovenous oxygen difference in heart failure with preserved ejection fraction patients: Is the muscle oxidative phenotype certainly involved?

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Endurance training and maximal oxygen consumption with ageing: Role of maximal cardiac output and oxygen extraction

Abstract: The improvement in VO2max following endurance training is a linear function of Qmax, but not Ca-vO2max, through healthy ageing.

Cited by 61 publications

References 55 publications

Graded Exercise Testing Protocols for the Determination of VO2max: Historical Perspectives, Progress, and Future Considerations

Graded Exercise Testing Protocols for the Determination of VO2max: Historical Perspectives, Progress, and Future Considerations

Balancing the evidence on the cardiovascular determinants of oxygen uptake improvement after endurance training in the elderly: What are the next steps?

Reduced arteriovenous oxygen difference in heart failure with preserved ejection fraction patients: Is the muscle oxidative phenotype certainly involved?

Contact Info

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Resources

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Graded Exercise Testing Protocols for the Determination of VO₂max: Historical Perspectives, Progress, and Future Considerations

Graded Exercise Testing Protocols for the Determination of VO₂max: Historical Perspectives, Progress, and Future Considerations