Long-lasting exercise involvement protects against decline in V̇O2max and V̇O2 kinetics in moderately active women

Author(s):  
Damir Zubac ◽  
Vladimir Ivančev ◽  
Zoran Valić ◽  
Boštjan Šimunič

We studied the effects of age on different physiological parameters, including those derived from (i) maximal cardiopulmonary exercise testing (CPET), (ii) moderate-intensity step transitions, and (iii) tensiomyography (TMG)-derived variables in moderately active women. Twenty-eight women (age, 19 to 53 years), completed 3 laboratory visits, including baseline data collection, TMG assessment, maximal oxygen uptake test via CPET, and a step-transition test from 20 W to a moderate-intensity cycling power output (PO), corresponding to oxygen uptake at 90% gas exchange threshold. During the step transitions, breath-by-breath pulmonary oxygen uptake, near infrared spectroscopy derived muscle deoxygenation (ΔHHb), and beat-by-beat cardiovascular response were continuously monitored. There were no differences observed between the young and middle-aged women in their maximal oxygen uptake and peak PO, while the maximal heart rate (HR) was 12 bpm lower in middle-aged compared with young (p = 0.016) women. Also, no differences were observed between the age groups in τ pulmonary oxygen uptake, ΔHHb, and τHR during on-transients. The first regression model showed that age did not attenuate the maximal CPET capacity in the studied population (p = 0.638), while in the second model a faster τ pulmonary oxygen uptake, combined with shorter TMG-derived contraction time (Tc) of the vastus lateralis (VL), were associated with a higher maximal oxygen uptake (∼30% of explained variance, p = 0.039). In conclusion, long lasting exercise involvement protects against a maximal oxygen uptake and τpulmonary oxygen uptake deterioration in moderately active women. Novelty: Faster τ pulmonary oxygen uptake and shorter Tc of the VL explain 33% of the variance in superior maximal oxygen uptake attainment. No differences between age groups were found in τ pulmonary oxygen uptake, τΔHHb, and τHR during on-transients.

2019 ◽  
Vol 127 (4) ◽  
pp. 1140-1149 ◽  
Author(s):  
Joel Rocha ◽  
Norita Gildea ◽  
Donal O’Shea ◽  
Simon Green ◽  
Mikel Egaña

The pulmonary oxygen uptake (V̇o2) kinetics during the transition to moderate-intensity exercise is slowed in individuals with type 2 diabetes (T2D), at least in part because of limitations in O2 delivery. The present study tested the hypothesis that a prior heavy-intensity warm-up or “priming” exercise (PE) bout would accelerate V̇o2 kinetics in T2D, because of a better matching of O2 delivery to utilization. Twelve middle-aged individuals with T2D and 12 healthy controls (ND) completed moderate-intensity constant-load cycling bouts either without (Mod A) or with (Mod B) prior PE. The rates of muscle deoxygenation (i.e., deoxygenated hemoglobin and myoglobin concentration, [HHb+Mb]) and oxygenation (i.e., tissue oxygenation index) were continuously measured by near-infrared spectroscopy at the vastus lateralis muscle. The local matching of O2 delivery to O2 utilization was assessed by the Δ[HHb+Mb]-to-ΔV̇o2 ratio. Both groups demonstrated an accelerated V̇O2 kinetics response during Mod B compared with Mod A (T2D, 32 ± 9 vs. 42 ± 12 s; ND, 28 ± 9 vs. 34 ± 8 s; means ± SD) and an elevated muscle oxygenation throughout Mod B, whereas the [HHb+Mb] amplitude was greater during Mod B only in individuals with T2D. The [HHb+Mb] kinetics remained unchanged in both groups. In T2D, Mod B was associated with a decrease in the “overshoot” relative to steady state in the Δ[HHb+Mb]-to-ΔV̇o2 ratio (1.17 ± 0.17 vs. 1.05 ± 0.15), whereas no overshoot was observed in the control group before (1.04 ± 0.12) or after (1.01 ± 0.12) PE. Our findings support a favorable priming-induced acceleration of the V̇o2 kinetics response in middle-aged individuals with uncomplicated T2D attributed to an enhanced matching of microvascular O2 delivery to utilization. NEW & NOTEWORTHY Heavy-intensity “priming” exercise (PE) elicited faster pulmonary oxygen uptake (V̇o2) kinetics during moderate-intensity cycling exercise in middle-aged individuals with type 2 diabetes (T2D). This was accompanied by greater near-infrared spectroscopy-derived muscle deoxygenation (i.e., deoxygenated hemoglobin and myoglobin concentration, [HHb+Mb]) responses and a reduced Δ[HHb+Mb]-to-ΔV̇o2 ratio. This suggests that the PE-induced acceleration in oxidative metabolism in T2D is a result of greater O2 extraction and better matching between O2 delivery and utilization.


1965 ◽  
Vol 20 (3) ◽  
pp. 432-436 ◽  
Author(s):  
K. Lange Andersen ◽  
Lars Hermansen

Maximal oxygen uptake and related respiratory and circulatory functions were measured in sedentary and well-trained middle-aged men. Maximal oxygen uptakes averaged 2.63 liter/min in sedentary men and 3.36 liter/min in well-trained men, the latter value being essentially the same as found in young untrained students. The heart rate/ oxygen uptake relationship was found to be the same for sedentary-living men, regardless of age, but maximal heart rate was lower in older men. The maximal heart rate is probably the same in well-trained as in sedentary middle-aged men, this in contrast to what has been observed in younger age groups, where training reduces maximal heart rate. The exercise-induced hyperventilation takes place at an oxygen uptake corresponding to 70–80% of the capacity, this being the same in trained and untrained, and essentially the same as found in young adult subjects. maximal O2 uptake Submitted on March 23, 1964


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Trine Karlsen ◽  
Ingeborg Megård Leinan ◽  
Fredrik Hjulstad Bækkerud ◽  
Kari Margrethe Lundgren ◽  
Atefe Tari ◽  
...  

Background. To discuss the cardiovascular and pulmonary physiology and common risk factors of an 80-year-old man with a world record maximal oxygen uptake of 50 mL·kg−1·min−1.Methods. Case report.Results. His maximal oxygen uptake of 3.31 L·min−1, maximal heart rate of 175 beats·min−1, and maximal oxygen pulse of 19 mL·beats−1are high. He is lean (66.6 kg) and muscular (49% skeletal muscle mass). His echo parameters of mitral flow (left ventricular filling,E= 82 cm·s−1andE/A= 1.2) were normal for 40- to 60-year-old men. Systolic and diastolic function increased adequately during exercise, with no increase in left ventricular filling pressure. He has excellent pulmonary function (FVC = 4.31 L, FEV1 = 3.41, FEV1/FVC = 0.79, and DLCO = 12.0 Si1) and normal FMD and blood volumes (5.8 L). He has a high level of daily activity (10,900 steps·day−1and 2:51 hours·day−1of physical activity) and a lifelong history of physical activity.Conclusion. The man is in excellent cardiopulmonary fitness and is highly physically active. His cardiac and pulmonary functions are above expectations for his age, and his VO2maxis comparable to that of an inactive 25-year-old and of a normal, active 35-year-old Norwegian man.


Author(s):  
Norita Gildea ◽  
Adam McDermott ◽  
Joel Rocha ◽  
Donal O'Shea ◽  
Simon Green ◽  
...  

We assessed the time course of changes in oxygen uptake (V̇O2) and muscle deoxygenation (i.e., deoxygenated haemoglobin and myoglobin, [HHb+Mb]) kinetics during transitions to moderate-intensity cycling following 12-weeks of low-volume high-intensity interval training (HIIT) vs. moderate-intensity continuous training (MICT) in adults with type 2 diabetes (T2D). Participants were randomly assigned to MICT (n=10, 50 min of moderate-intensity cycling), HIIT (n=9, 10x1 min at ~90% maximal heart rate) or non-exercising control (n=9) groups. Exercising groups trained 3 times per week and measurements were taken every 3 weeks. [HHb+Mb] kinetics were measured by near-infrared spectroscopy at the vastus lateralis muscle. The local matching of O2 delivery to O2 utilization was assessed by the Δ[HHb+Mb]/ΔV̇O2ratio. The pretraining time constant of the primary phase of V̇O2 (τV̇O2p ) decreased (P<0.05) at wk 3 of training in both MICT (from 44±12 to 32±5 s) and HIIT (from 42±8 to 32 ± 4 s) with no further changes thereafter; while no changes were reported in controls. The pretraining overall dynamic response of muscle deoxygenation (τ'[HHb+Mb]) was faster than τV̇O2p in all groups, resulting in Δ[HHb+Mb]/V̇O2p showing a transient "overshoot" relative to the subsequent steady-state level. After 3 wks, the Δ[HHb+Mb]/V̇O2p overshoot was eliminated only in the training groups, so that τ'[HHb+Mb] was not different to τV̇O2p in MICT and HIIT. The enhanced V̇O2 kinetics response consequent to both MICT and HIIT in T2D was likely attributed to a training-induced improvement in matching of O2 delivery to utilization.


1981 ◽  
Vol 50 (4) ◽  
pp. 824-828 ◽  
Author(s):  
M. N. Sawka ◽  
R. M. Glaser ◽  
L. L. Laubach ◽  
O. Al-Samkari ◽  
A. G. Suryaprasad

The purpose of this study was to quantitate the maximal power output (POmax), peak oxygen uptake (peak VO2), and maximal heart rate (HRmax) for wheelchair ergometer (WERG) exercise performed by three groups of disabled males: young adult (20-30 yr), middle-aged (50-60 yr), and elderly (80-90 yr). These subjects, who were confined to wheelchairs for similar time periods (mean = 11.7 yr), participated in progressive-intensity discontinuous test protocols on a WERG. Lower (P less than 0.01) mean POmax, peak VO2, and HRmax values were found with advancing age groups. In relationship to age, decreases in POmax and HRmax values were best described by parabolic models, whereas decreases in peak VO2 values were best described by a linear model. In comparison with young adults (83 W, 27 ml . kg-1 . min-1), surprisingly low POmax and peak VO2 values were found for the middle-aged (16 W, 10 ml . kg-1 . min-1) and elderly (7 W, 8 ml . kg-1 . min-1). When our peak VO2 data were combined with other data in the literature for upper body exercise by male disabled individuals, a decrease of 0.19 1 . min-1 or 2.9 ml . kg-1 . min-1 per decade of life was found.


2018 ◽  
Vol 39 (03) ◽  
pp. 198-203 ◽  
Author(s):  
Don Keiller ◽  
Dan Gordon

AbstractThis study investigates heart rate (HR), in 11 young adults (22.4±3.21yr), at V̇O2max, to ascertain whether measured maximal heart rate (HRmax), as determined by a plateau in HR (HRplat), can reliably confirm V̇O2max. V̇O2max and HRplat were determined, using the parameters of a V̇O2≤50 ml•min−1 and a ∆HR≤2b•min−1, respectively, over the final 60 s of sampling. V̇O2 was also independently determined using a verification phase protocol. A HRplat was achieved by 91% of participants (∆HR=1.3±1b•min−1) and critically the time at which HRmax was reached coincided with that at which V̇O2max was achieved. Moreover RER and ΔRER criteria were reached significantly earlier (p<0.05) than V̇O2max, whilst age-related heart rate maximums (HRage), were not achieved by many participants. The results suggest that a HRplat ≤2 b•min−1 is a more accurate method, within the group tested, to determine whether a ‘true’ V̇O2max has been achieved, than other secondary criteria and potentially avoids the requirement for an additional verification phase.


Author(s):  
Alan R Barker ◽  
Neil Armstrong

The pulmonary oxygen uptake (pV̇O2) kinetic response to exercise provides valuable non-invasive insight into the control of oxidative phosphorylation and determinants of exercise tolerance in children and adolescents. Few methodologically robust studies have investigated pV̇O2 kinetics in children and adolescents, but age- and sex-related differences have been identified. There is a clear age-related slowing of phase II pV̇O2 kinetics during heavy and very heavy exercise, with a trend showing during moderate intensity exercise. During heavy and very heavy exercise the oxygen cost is higher for phase II and the pV̇O2 component is truncated in children. Sex-related differences occur during heavy, but not moderate, intensity exercise, with boys having faster phase II pV̇O2 kinetics and a smaller pV̇O2 slow component compared to girls. The mechanisms underlying these differences are likely related to changes in phosphate feedback controllers of oxidative phosphorylation, muscle oxygen delivery, and/or muscle fibre recruitment strategies.


2019 ◽  
Vol 6 (10) ◽  
pp. 190639
Author(s):  
Lucas Raphael Bento Silva ◽  
Paulo Roberto Viana Gentil ◽  
Thomas Beltrame ◽  
Marco Antônio Basso Filho ◽  
Fagner Medeiros Alves ◽  
...  

The aim of this study was to compare the heart rate (HR) dynamics and variability before and after high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) protocols with workloads based on treadmill workload at which maximal oxygen uptake was achieved ( WL V ˙ O 2 max ) . Ten participants performed cardiopulmonary exercise testing (CPET) to obtain oxygen uptake ( WL V ˙ O 2 max ) . All training protocols were performed on a treadmill, with 0% grade, and had similar total distance. The MICT was composed by 21 min at 70% of WL V ˙ O 2 max . The first HIIT protocol (HIIT-30 : 30) was composed by 29 repetitions of 30 s at 100% of s V ˙ O 2 max and the second HIIT protocol (HIIT-4 : 3) was composed by three repetitions of 4 min at 90% of WL V ˙ O 2 max . Before, during and after each training protocol, HR dynamics and variability (HRV) were analysed by standard kinetics and linear (time and frequency domains). The repeated measures analysis of variance indicated that the HR dynamics, which characterizes the speed of HR during the rest to exercise transition, was statistically ( p < 0.05) slower during MICT in comparison to both HIIT protocols. The HRV analysis, which characterizes the cardiac autonomic modulation during the exercise recovery, was statistically higher in HIIT-4 : 3 in comparison to MICT and HIIT-30 : 30 protocols ( p < 0.005 and p = 0.012, respectively), suggesting that the HIIT-4 : 3 induced higher sympathetic and lower parasympathetic modulation during exercise in comparison to the other training protocols. In conclusion, HIIT-4 : 3 demonstrated post-exercise sympathetic hyperactivity and a higher HRpeak, while the HIIT-30 : 30 and MICT resulted in better HRV and HR in the exercise-recovery transition. The cardiac autonomic balance increased in HIIT-30 : 30 while HIIT-4 : 3 induced sympathetic hyperactivity and cardiac overload.


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