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Weston ME, Armstrong N, Bond B, Tomlinson OW, Williams CA, Barker AR. The Influence of Acute Hypoxia on Oxygen Uptake and Muscle Oxygenation Kinetics During Cycling Exercise in Prepubertal Boys. Pediatr Exerc Sci 2024:1-8. [PMID: 38925533 DOI: 10.1123/pes.2023-0089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 04/30/2024] [Accepted: 05/05/2024] [Indexed: 06/28/2024]
Abstract
PURPOSE To examine the effect of normobaric hypoxia on pulmonary oxygen uptake (V˙O2) and muscle oxygenation kinetics during incremental and moderate-intensity exercise in children. METHODS Eight prepubertal boys (9-11 y) performed incremental cycle tests to exhaustion in both normoxia and hypoxia (fraction of inspired O2 of 15%) followed by repeat 6-minute transitions of moderate-intensity exercise in each condition over subsequent visits. RESULTS Maximal oxygen uptake (V˙O2max) was reduced in hypoxia compared with normoxia (1.69 [0.20] vs 1.87 [0.26] L·min-1, P = .028), although the gas exchange threshold was not altered in absolute terms (P = .33) or relative to V˙O2max (P = .78). During moderate-intensity exercise, the phase II V˙O2 time constant (τ) was increased in hypoxia (18 [9] vs 24 [8] s, P = .025), with deoxyhemoglobin τ unchanged (17 [8] vs 16 [6], P ≥ .28). CONCLUSIONS In prepubertal boys, hypoxia reduced V˙O2max and slowed V˙O2 phase II kinetics during moderate-intensity exercise, despite unchanged deoxyhemoglobin kinetics. These data suggest an oxygen delivery dependence of V˙O2max and moderate-intensity V˙O2 kinetics under conditions of reduced oxygen availability in prepubertal boys.
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Affiliation(s)
- Max E Weston
- Children's Health and Exercise Research Center, Public Health and Sports Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter,United Kingdom
- Department of Physiology, School of Medicine, Trinity College Dublin, Dublin,Ireland
| | - Neil Armstrong
- Children's Health and Exercise Research Center, Public Health and Sports Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter,United Kingdom
| | - Bert Bond
- Children's Health and Exercise Research Center, Public Health and Sports Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter,United Kingdom
| | - Owen W Tomlinson
- Children's Health and Exercise Research Center, Public Health and Sports Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter,United Kingdom
| | - Craig A Williams
- Children's Health and Exercise Research Center, Public Health and Sports Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter,United Kingdom
| | - Alan R Barker
- Children's Health and Exercise Research Center, Public Health and Sports Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter,United Kingdom
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Hovorka M, Prinz B, Simon D, Zöger M, Rumpl C, Nimmerichter A. Long-Term Alterations in Pulmonary V˙O2 and Muscle Deoxygenation On-Kinetics During Heavy-Intensity Exercise in Competitive Youth Cyclists: A Cohort Study. Pediatr Exerc Sci 2024:1-7. [PMID: 38714302 DOI: 10.1123/pes.2023-0110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 02/20/2024] [Accepted: 03/12/2024] [Indexed: 05/09/2024]
Abstract
PURPOSE The aim of this investigation was to assess alterations of pulmonary oxygen uptake (V˙O2) and muscle deoxygenation on-kinetics during heavy-intensity cycling in youth cyclists over a period of 15 months. METHODS Eleven cyclists (initial age, 14.3 [1.6] y; peak V˙O2, 62.2 [4.5] mL·min-1·kg-1) visited the laboratory twice on 3 occasions within 15 months. Participants performed an incremental ramp exercise test and a constant workrate test within the heavy-intensity domain during the first visit and second visit, respectively. Subsequently, parameter estimates of the V˙O2 and muscle deoxygenation on-kinetics were determined with mono-exponential models. RESULTS The V˙O2 phase II time constant decreased from occasion 1 (34 [4] s) to occasion 2 (30 [4] s, P = .005) and 3 (28 [4] s, P = .010). However, no significant alteration was observed between occasions 2 and 3 (P = .565). The V˙O2 slow component amplitude either expressed in absolute values (ie, L·min-1) or relative to end exercise V˙O2 (ie, %) showed no significant changes throughout the study (P = .972 and .996). Furthermore, the muscle deoxygenation on-kinetic mean response time showed no significant changes throughout the study (18 [8], 18 [3], and 16 [5] s for occasions 1, 2, and 3, respectively; P = .279). CONCLUSION These results indicate proportional enhancements of local muscle oxygen distribution and utilization, which both contributed to the speeding of the V˙O2 on-kinetics herein.
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Affiliation(s)
- Matthias Hovorka
- Training and Sports Sciences, University of Applied Sciences Wiener Neustadt, Wiener Neustadt,Austria
- Centre for Sport Science and University Sports, University of Vienna, Vienna,Austria
- Doctoral School of Pharmaceutical, Nutritional and Sport Sciences, University of Vienna, Vienna,Austria
| | - Bernhard Prinz
- Training and Sports Sciences, University of Applied Sciences Wiener Neustadt, Wiener Neustadt,Austria
| | - Dieter Simon
- Training and Sports Sciences, University of Applied Sciences Wiener Neustadt, Wiener Neustadt,Austria
| | - Manfred Zöger
- Training and Sports Sciences, University of Applied Sciences Wiener Neustadt, Wiener Neustadt,Austria
| | - Clemens Rumpl
- Training and Sports Sciences, University of Applied Sciences Wiener Neustadt, Wiener Neustadt,Austria
| | - Alfred Nimmerichter
- Training and Sports Sciences, University of Applied Sciences Wiener Neustadt, Wiener Neustadt,Austria
- Centre for Sport Science and University Sports, University of Vienna, Vienna,Austria
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Hovorka M, Prinz B, Simon D, Zöger M, Rumpl C, Nimmerichter A. Longitudinal alterations of pulmonary V.O2 on-kinetics during moderate-intensity exercise in competitive youth cyclists are related to alterations in the balance between microvascular O2 distribution and muscular O2 utilization. Front Sports Act Living 2022; 4:982548. [DOI: 10.3389/fspor.2022.982548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 10/31/2022] [Indexed: 11/17/2022] Open
Abstract
PurposeThe main purpose of the current study was to investigate the dynamic adjustment of pulmonary oxygen uptake (V.O2) in response to moderate-intensity cycling on three occasions within 15 months in competitive youth cyclists. Furthermore, the muscle Δdeoxy[heme] on-kinetics and the Δdeoxy[heme]-to-V.O2 ratio were modeled to examine possible mechanistic basis regulating pulmonary V.O2 on-kinetics.MethodsEleven cyclists (initial age, 14.3 ± 1.6 y; peak V.O2, 62.2 ± 4.5 mL.min−1.kg−1) with a training history of 2–5 years and a training volume of ~10 h per week participated in this investigation. V.O2 and Δdeoxy[heme] responses during workrate-transitions to moderate-intensity cycling were measured with breath-by-breath spirometry and near-infrared spectroscopy, respectively, and subsequently modeled with mono-exponential models to derive parameter estimates. Additionally, a normalized Δdeoxy[heme]-to-V.O2 ratio was calculated for each participant. One-way repeated-measures ANOVA was used to assess effects of time on the dependent variables of the responses.ResultsThe V.O2 time constant remained unchanged between the first (~24 s) and second visit (~22 s, P > 0.05), whereas it was significantly improved through the third visit (~13 s, P = 0.006–0.013). No significant effects of time were revealed for the parameter estimates of the Δdeoxy[heme] response (P > 0.05). A significant Δdeoxy[heme]-to-V.O2 ratio “overshoot” was evident on the first (1.09 ± 0.10, P = 0.006) and second (1.05 ± 0.09, P = 0.047), though not the third (0.97 ± 0.10, P > 0.05), occasion. These “overshoots” showed strong positive relationships with the V.O2 time constant during the first (r = 0.66, P = 0.028) and second visit (r = 0.76, P = 0.007). Further, strong positive relationships have been observed between the individual changes of the fundamental phase τp and the Δdeoxy[heme]-to-V.O2 ratio “overshoot” from occasion one to two (r = 0.70, P = 0.017), and two to three (r = 0.74, P = 0.009).ConclusionThis suggests that improvements in muscle oxygen provision and utilization capacity both occurred, and each may have contributed to enhancing the dynamic adjustment of the oxidative “machinery” in competitive youth cyclists. Furthermore, it indicates a strong link between an oxygen maldistribution within the tissue of interrogation and the V.O2 time constant.
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Bar‐Yoseph R, Radom‐Aizik S, Coronato N, Moradinasab N, Barstow TJ, Stehli A, Brown D, Cooper DM. Heart rate and gas exchange dynamic responses to multiple brief exercise bouts (MBEB) in early- and late-pubertal boys and girls. Physiol Rep 2022; 10:e15397. [PMID: 35923083 PMCID: PMC9349595 DOI: 10.14814/phy2.15397] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/24/2022] [Accepted: 07/02/2022] [Indexed: 04/28/2023] Open
Abstract
Natural patterns of physical activity in youth are characterized by brief periods of exercise of varying intensity interspersed with rest. To better understand systemic physiologic response mechanisms in children and adolescents, we examined five responses [heart rate (HR), respiratory rate (RR), oxygen uptake (V̇O2 ), carbon dioxide production (V̇CO2 ), and minute ventilation (V̇E), measured breath-by-breath] to multiple brief exercise bouts (MBEB). Two groups of healthy participants (early pubertal: 17 female, 20 male; late-pubertal: 23 female, 21 male) performed five consecutive 2-min bouts of constant work rate cycle-ergometer exercise interspersed with 1-min of rest during separate sessions of low- or high-intensity (~40% or 80% peak work, respectively). For each 2-min on-transient and 1-min off-transient we calculated the average value of each cardiopulmonary exercise testing (CPET) variable (Y̅). There were significant MBEB changes in 67 of 80 on- and off-transients. Y̅ increased bout-to-bout for all CPET variables, and the magnitude of increase was greater in the high-intensity exercise. We measured the metabolic cost of MBEB, scaled to work performed, for the entire 15 min and found significantly higher V̇O2 , V̇CO2 , and V̇E costs in the early-pubertal participants for both low- and high-intensity MBEB. To reduce breath-by-breath variability in estimation of CPET variable kinetics, we time-interpolated (second-by-second), superimposed, and averaged responses. Reasonable estimates of τ (<20% coefficient of variation) were found only for on-transients of HR and V̇O2 . There was a remarkable reduction in τHR following the first exercise bout in all groups. Natural patterns of physical activity shape cardiorespiratory responses in healthy children and adolescents. Protocols that measure the effect of a previous bout on the kinetics of subsequent bouts may aid in the clinical utility of CPET.
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Affiliation(s)
- Ronen Bar‐Yoseph
- Pediatric Exercise and Genomics Research CenterUniversity of California at IrvineIrvineCaliforniaUSA
- Pediatric Pulmonary DivisionRuth Children's Hospital, Rambam Health Care CenterHaifaIsrael
| | - Shlomit Radom‐Aizik
- Pediatric Exercise and Genomics Research CenterUniversity of California at IrvineIrvineCaliforniaUSA
| | - Nicholas Coronato
- University of VirginiaCharlottesvilleVirginiaUSA
- United States Military AcademyWest PointNew YorkUSA
| | | | | | - Annamarie Stehli
- Pediatric Exercise and Genomics Research CenterUniversity of California at IrvineIrvineCaliforniaUSA
| | - Don Brown
- University of VirginiaCharlottesvilleVirginiaUSA
| | - Dan M. Cooper
- Pediatric Exercise and Genomics Research CenterUniversity of California at IrvineIrvineCaliforniaUSA
- Department of Pediatrics, Institute for Clinical and Translational Science, and Pediatric Exercise and Genomics Research CenterUniversity of CaliforniaIrvineCaliforniaUSA
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Borghi-Ricardo M, Simões RP, Santos DA, Archiza B, Borghi-Silva A. Effects of Aging on Hemodynamic Kinetics in Different Intensities of Dynamic Exercise. Int J Sports Med 2021; 43:61-67. [PMID: 34157777 DOI: 10.1055/a-1487-6628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Healthy aging hemodynamics is known to exhibit a time-dependent loss of function. We aimed at verifying whether older men would have a slowed cardiac output and stroke volume dynamics in response to the onset ("on") and on recovery ("off") of exercise in comparison to young men. Twenty healthy active men (10 young and 10 older) were recruited. Participants performed an incremental cardiopulmonary exercise testing on a cycle ergometer, and on another day, 3 constant workload tests in different intensities. Compared to younger, older men exhibited a slower cardiac output and stroke volume dynamics in both on and off transients for all exercise intensities (all P < 0.05). During higher intensities, both younger and older men had slower hemodynamic kinetics compared to lower intensities (all P < 0.05). There was strong negative relationship between the time constant of cardiac output on-kinetics during high-intensity with maximal exercise performance in both groups (r = -0.88, P < 0.01). We interpret these findings to mean that healthy older men have slowed hemodynamic kinetics compared to younger, but this difference becomes less evident in higher intensities of exercise.
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Affiliation(s)
| | | | - Daniel Augusto Santos
- Department of Physiotherapy, Cardiopulmonary Physiotherapy Laboratory, Nucleus of Research in Physical Exercise, Federal University of Sao Carlos, Sao Carlos, Brazil
| | - Bruno Archiza
- Department of Physiotherapy, Cardiopulmonary Physiotherapy Laboratory, Nucleus of Research in Physical Exercise, Federal University of Sao Carlos, Sao Carlos, Brazil
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Prinz B, Zöger M, Tschan H, Nimmerichter A. Oxygen Uptake Kinetics in Endurance Trained Youth and Adult Cyclists. JOURNAL OF SPORTS SCIENCE AND MEDICINE 2021; 20:398-403. [PMID: 34267578 DOI: 10.52082/jssm.2021.398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 04/24/2021] [Indexed: 11/24/2022]
Abstract
Previous studies reported faster pulmonary oxygen uptake kinetics at the onset of exercise in untrained youth compared with adults. Whether or not these differences are identical for trained groups have not been examined. The purpose of this study was to compare ˙VO2 kinetics of youth and adult cyclists at moderate and heavy-intensity exercise. Thirteen adult (age: 23.2 ± 4.8 years; ˙VO2peak 68.4 ± 6.8 mL·min-1.kg-1) and thirteen youth cyclists (age: 14.3 ± 1.5 years; ˙VO2peak 61.7 ± 4.3 mL·min-1.kg-1) completed a series of 6-min square wave exercises at moderate and heavy-intensity exercise at 90 rev·min-1. A two-way repeated-measure ANOVA was conducted to identify differences between groups and intensities. The time constant, time delay and the mean response time were not significantly different between youth and adult cyclists (p > 0.05). We found significant differences between intensities, with a faster time constant during moderate than heavy-intensity exercise in youth (24.1 ± 7.0 s vs. 31.8 ± 5.6 s; p = 0.004) and adults (22.7 ± 5.6 s vs. 28.6 ± 5.7 s; p < 0.001). The present data suggest that the effect of training history in adult cyclists compensate for the superior primary response of the oxygen uptake kinetics typically seen in youth compared to adults. Furthermore, the ˙VO2 response is dependent of work rate intensity in trained youth and adult cyclists.
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Affiliation(s)
- Bernhard Prinz
- Training and Sports Sciences, University of Applied Sciences, Wiener Neustadt, Austria.,Centre for Sport Science and University Sports, University of Vienna, Austria
| | - Manfred Zöger
- Training and Sports Sciences, University of Applied Sciences, Wiener Neustadt, Austria
| | - Harald Tschan
- Centre for Sport Science and University Sports, University of Vienna, Austria
| | - Alfred Nimmerichter
- Training and Sports Sciences, University of Applied Sciences, Wiener Neustadt, Austria
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Combret Y, Medrinal C, Prieur G, Robledo Quesada A, Gillot T, Gravier FE, Bonnevie T, Lamia B, Le Roux P, Reychler G. Oxygen uptake kinetics during treadmill walking in adolescents with clinically stable cystic fibrosis. Physiother Theory Pract 2021; 38:1389-1397. [PMID: 33390080 DOI: 10.1080/09593985.2020.1868029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Background: Oxygen uptake (V̇O2) kinetics have been shown to be slowed in adolescents with cystic fibrosis (CF) during heavy-intensity cycling and maximal exercise testing.Objectives: This study investigated V̇O2 kinetics in adolescents with CF compared to control adolescents (CON) during a treadmill-walking exercise.Methods: Eight adolescents with CF and mild-to-moderate pulmonary obstruction (5 girls; 13.1 ± 2.5 years; FEV1 67.8 ± 21.4%) and 18 CON adolescents (10 girls; 13.8 ± 1.8 years) were recruited. Pulmonary gas exchange and ventilation were measured during a single transition of 10 min of treadmill walking and a 5 min seated recovery period. Participant's walking speed was determined during a one-minute self-paced walking task along a 50-m corridor. A six-parameter, non-linear regression model was used to describe the changes in V̇O2 function during the treadmill walking and recovery, with monoexponential curve fitting used to describe the mean response time (MRT1) at the onset of exercise, and the half-life (T1/2V̇O2) at the offset of exercise. V̇O2 baseline and amplitude, minute ventilation and respiratory equivalents were recorded.Results: V̇O2 kinetics were slower in CF group compared to CON group during the treadmill walking with a greater MRT1 (32 ± 14 s vs 21 ± 16 s; p = .04, effect size = 0.75). The T1/2V̇O2 was prolonged during recovery in CF group compared to CON group (86 ± 24 s vs 56 ± 22 s; p = .04, effect size = 1.31). The mean VE/V̇CO2 during exercise was the only parameter significantly greater in CF group compared to CON group (32.9 ± 2.3 vs 29.0 ± 2.4; p < .01, effect size = 1.66). Conclusion: V̇O2 kinetics were found to be slowed in adolescents with CF during treadmill walking.
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Affiliation(s)
- Yann Combret
- Physiotherapy Department, Le Havre Hospital, Montivilliers, France.,Institut De Recherche Et d'Expérimentation Clinique (IREC), Pôle De Pneumologie, ORL and Dermatologie, Université Catholique De Louvain, Brussels, Belgium
| | - Clément Medrinal
- Physiotherapy Department, Le Havre Hospital, Montivilliers, France.,Erphan, Paris-Saclay University, UVSQ, Versailles, France.,Saint Michel School of Physiotherapy, Paris, France
| | - Guillaume Prieur
- Physiotherapy Department, Le Havre Hospital, Montivilliers, France.,Institut De Recherche Et d'Expérimentation Clinique (IREC), Pôle De Pneumologie, ORL and Dermatologie, Université Catholique De Louvain, Brussels, Belgium.,UPRES EA3830 - GRHV, Normandie University, UNIROUEN, Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France
| | | | - Timothée Gillot
- Cetaps, EA3832, Rouen University, Mont Saint Aignan, France.,School of Physiotherapy, Rouen University Hospital, Rouen, France
| | - Francis-Edouard Gravier
- UPRES EA3830 - GRHV, Normandie University, UNIROUEN, Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France.,ADIR Association, Rouen University Hospital, Bois-Guillaume, France
| | - Tristan Bonnevie
- UPRES EA3830 - GRHV, Normandie University, UNIROUEN, Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France.,ADIR Association, Rouen University Hospital, Bois-Guillaume, France
| | - Bouchra Lamia
- UPRES EA3830 - GRHV, Normandie University, UNIROUEN, Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France.,Pulmonology Department, Le Havre Hospital, Montivilliers, France.,Intensive Care Unit, Respiratory Department, Rouen University Hospital, Rouen, France
| | - Pascal Le Roux
- Pediatric Department, Le Havre Hospital, Montivilliers, France
| | - Grégory Reychler
- Institut De Recherche Et d'Expérimentation Clinique (IREC), Pôle De Pneumologie, ORL and Dermatologie, Université Catholique De Louvain, Brussels, Belgium.,Department of Physical Medicine and Rehabilitation, Saint-Luc University Clinics, Brussels, Belgium
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McNarry MA, Winn CON, Davies GA, Eddolls WTB, Mackintosh KA. Effect of High-Intensity Training and Asthma on the V˙O2 Kinetics of Adolescents. Med Sci Sports Exerc 2020; 52:1322-1329. [PMID: 31972630 DOI: 10.1249/mss.0000000000002270] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE High-intensity interval training (HIIT) represents a potent stimulus to the dynamic oxygen uptake (V˙O2) response in adults, but whether the same is evident in youth is unknown. HIIT has also been suggested to place a lower demand on the respiratory system, decreasing the likelihood of exacerbation in those with respiratory conditions, such as asthma. METHODS Sixty-nine adolescents (13.6 ± 0.9 yr; 36 asthma) took part, 35 of which (17 asthma) participated in a 30-min HIIT intervention three times a week for 6 months. Each participant completed an incremental ramp test to volitional exhaustion and three heavy-intensity constant work rate tests to determine the dynamic V˙O2, heart rate, and deoxyhemoglobin response at baseline, midintervention, postintervention and at a 3-month follow-up. RESULTS There was no influence of asthma at baseline or in response to the intervention. Participants in the intervention group demonstrated a faster V˙O2 time constant (τp) after intervention (intervention: 29.2 ± 5.7 s vs control: 34.2 ± 6.5 s; P = 0.003), with these differences maintained at follow-up (intervention: 32.5 ± 5.5 s vs control: 37.3 ± 8.7 s; P = 0.008). The intervention was associated with a speeding of the concentration of deoxyhemoglobin τ (pre: 20.1 ± 4.7 s vs post: 18.2 ± 4.1 s; P = 0.05) compared with a slowing over the same time period in the control participants (pre: 17.9 ± 4.9 s vs post: 20.1 ± 4.6 s; P = 0.012). Heart rate kinetics were not altered (pre: 46.5 ± 12.2 s vs post: 47.7 ± 11.1 s; P = 0.98). CONCLUSION These findings highlight the potential utility of school-based HIIT as a strategy to enhance the V˙O2 kinetics of youth, regardless of the presence of asthma.
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Affiliation(s)
- Melitta A McNarry
- Applied Sports Technology, Exercise and Medicine (A-STEM) Research Centre, College of Engineering, Bay Campus, Swansea University, Swansea, UNITED KINGDOM
| | | | - Gwyneth A Davies
- Swansea University Medical School, Singleton Campus, Swansea University, Swansea, UNITED KINGDOM
| | - William T B Eddolls
- Applied Sports Technology, Exercise and Medicine (A-STEM) Research Centre, College of Engineering, Bay Campus, Swansea University, Swansea, UNITED KINGDOM
| | - Kelly A Mackintosh
- Applied Sports Technology, Exercise and Medicine (A-STEM) Research Centre, College of Engineering, Bay Campus, Swansea University, Swansea, UNITED KINGDOM
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Schindel CS, Schiwe D, Heinzmann-Filho JP, Gheller MF, Campos NE, Pitrez PM, Donadio MVF. Determinants of exercise capacity in children and adolescents with severe therapy-resistant asthma. J Asthma 2020; 59:115-125. [PMID: 33026845 DOI: 10.1080/02770903.2020.1833915] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
OBJECTIVE To evaluate the exercise capacity of children and adolescents with severe therapy resistant asthma (STRA) aiming to identify its main determinants. METHODS Cross-sectional study including individuals aged 6-18 years with a diagnosis of STRA. Clinical (age and gender), anthropometric (weight, height and body mass index) and disease control data were collected. Lung function (spirometry), cardiopulmonary exercise testing (CPET) and exercise-induced bronchoconstriction (EIB) test were performed. RESULTS Twenty-four patients aged 11.5 ± 2.6 years were included. The mean forced expiratory volume in one second (FEV1) was 91.3 ± 9.2%. EIB occurred in 54.2% of patients. In CPET, the peak oxygen uptake (VO2peak) was 34.1 ± 7.8 mL kg-1 min-1. A significant correlation between ventilatory reserve and FEV1 (r = 0.57; p = 0.003) was found. Similarly, there was a significant correlation between CPET and percent of FEV1 fall in the EIB test for both VE/VO2 (r = 0.47; p = 0.02) and VE/VCO2 (r = 0.46; p = 0.02). Patients with FEV1<80% had lower ventilatory reserve (p = 0.009). In addition, resting heart rate correlated with VO2peak (r=-0.40; p = 0.04), VE/VO2 (r = 0.46; p = 0.02) and VE/VCO2 (r = 0.48; p = 0.01). CONCLUSIONS Exercise capacity is impaired in approximately 30% of children and adolescents with STRA. The results indicate that different aspects of aerobic fitness are influenced by distinct determinants, including lung function and EIB.
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Affiliation(s)
- Cláudia Silva Schindel
- Laboratório de Atividade Física em Pediatria, Centro Infant, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil
| | - Daniele Schiwe
- Laboratório de Atividade Física em Pediatria, Centro Infant, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil
| | - João Paulo Heinzmann-Filho
- Laboratório de Atividade Física em Pediatria, Centro Infant, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil
| | - Mailise Fátima Gheller
- Laboratório de Atividade Física em Pediatria, Centro Infant, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil
| | - Natália Evangelista Campos
- Laboratório de Atividade Física em Pediatria, Centro Infant, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil
| | - Paulo Márcio Pitrez
- Centro Infant, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS) and Hospital Moinhos de Vento, Porto Alegre, Brazil
| | - Márcio Vinícius Fagundes Donadio
- Laboratório de Atividade Física em Pediatria, Centro Infant, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil
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10
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Breese BC, Saynor ZL, Barker AR, Armstrong N, Williams CA. Relationship between (non)linear phase II pulmonary oxygen uptake kinetics with skeletal muscle oxygenation and age in 11-15 year olds. Exp Physiol 2019; 104:1929-1941. [PMID: 31512297 DOI: 10.1113/ep087979] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 09/09/2019] [Indexed: 12/28/2022]
Abstract
NEW FINDINGS What is the central question of this study? Do the phase II parameters of pulmonary oxygen uptake ( V ̇ O 2 ) kinetics display linear, first-order behaviour in association with alterations in skeletal muscle oxygenation during step cycling of different intensities or when exercise is initiated from an elevated work rate in youths. What is the main finding and its importance? Both linear and non-linear features of phase II V ̇ O 2 kinetics may be determined by alterations in the dynamic balance between microvascular O2 delivery and utilization in 11-15 year olds. The recruitment of higher-order (i.e. type II) muscle fibres during 'work-to-work' cycling might be responsible for modulating V ̇ O 2 kinetics with chronological age. ABSTRACT This study investigated in 19 male youths (mean age: 13.6 ± 1.1 years, range: 11.7-15.7 years) the relationship between pulmonary oxygen uptake ( V ̇ O 2 ) and muscle deoxygenation kinetics during moderate- and very heavy-intensity 'step' cycling initiated from unloaded pedalling (i.e. U → M and U → VH) and moderate to very heavy-intensity step cycling (i.e. M → VH). Pulmonary V ̇ O 2 was measured breath-by-breath along with the tissue oxygenation index (TOI) of the vastus lateralis using near-infrared spectroscopy. There were no significant differences in the phase II time constant ( τ V ̇ O 2 p ) between U → M and U → VH (23 ± 6 vs. 25 ± 7 s; P = 0.36); however, the τ V ̇ O 2 p was slower during M → VH (42 ± 16 s) compared to other conditions (P < 0.001). Quadriceps TOI decreased with a faster (P < 0.01) mean response time (MRT; i.e. time delay + τ) during U → VH (14 ± 2 s) compared to U → M (22 ± 4 s) and M → VH (20 ± 6 s). The difference (Δ) between the τ V ̇ O 2 p and MRT-TOI was greater during U → VH compared to U → M (12 ± 7 vs. 2 ± 7 s, P < 0.001) and during M → VH (23 ± 15 s) compared to other conditions (P < 0.02), suggesting an increased proportional speeding of fractional O2 extraction. The slowing of the τ V ̇ O 2 p during M → VH relative to U → M and U → VH correlated positively with chronological age (r = 0.68 and 0.57, respectively, P < 0.01). In youths, 'work-to-work' transitions slowed microvascular O2 delivery-to-O2 utilization with alterations in phase II V ̇ O 2 dynamics accentuated between the ages of 11 and 15 years.
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Affiliation(s)
- Brynmor C Breese
- School of Biomedical Sciences, Faculty of Medicine and Dentistry, University of Plymouth, Plymouth, UK
| | - Zoe L Saynor
- Department of Sport and Exercise Science, Faculty of Science, University of Portsmouth, Portsmouth, UK
| | - Alan R Barker
- Children's Health and Exercise Research Centre, Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Neil Armstrong
- Children's Health and Exercise Research Centre, Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Craig A Williams
- Children's Health and Exercise Research Centre, Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
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Why Do Children Have Faster VO 2 Kinetics?-A Response to Dotan (2019). Pediatr Exerc Sci 2019; 31:260-261. [PMID: 30943850 DOI: 10.1123/pes.2019-0032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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