Effects of priming exercise on the speed of adjustment of muscle oxidative metabolism at the onset of moderate-intensity step transitions in older adults

2012 ◽  
Vol 302 (10) ◽  
pp. R1158-R1166 ◽  
Author(s):  
Gabriela De Roia ◽  
Silvia Pogliaghi ◽  
Alessandra Adami ◽  
Christina Papadopoulou ◽  
Carlo Capelli

Aging is associated with a functional decline of the oxidative metabolism due to progressive limitations of both O2 delivery and utilization. Priming exercise (PE) increases the speed of adjustment of oxidative metabolism during successive moderate-intensity transitions. We tested the hypothesis that such improvement is due to a better matching of O2 delivery to utilization within the working muscles. In 21 healthy older adults (65.7 ± 5 yr), we measured contemporaneously noninvasive indexes of the overall speed of adjustment of the oxidative metabolism (i.e., pulmonary V̇o2 kinetics), of the bulk O2 delivery (i.e., cardiac output), and of the rate of muscle deoxygenation (i.e., deoxygenated hemoglobin, HHb) during moderate-intensity step transitions, either with (ModB) or without (ModA) prior PE. The local matching of O2 delivery to utilization was evaluated by the ΔHHb/ΔV̇o2 ratio index. The overall speed of adjustment of the V̇o2 kinetics was significantly increased in ModB compared with ModA ( P < 0.05). On the contrary, the kinetics of cardiac output was unaffected by PE. At the muscle level, ModB was associated with a significant reduction of the “overshoot” in the ΔHHb/ΔV̇o2 ratio compared with ModA ( P < 0.05), suggesting an improved O2 delivery. Our data are compatible with the hypothesis that, in older adults, PE, prior to moderate-intensity exercise, beneficially affects the speed of adjustment of oxidative metabolism due to an acute improvement of the local matching of O2 delivery to utilization.

2020 ◽  
Vol 10 (11) ◽  
pp. 813 ◽  
Author(s):  
Katharina Stute ◽  
Nicole Hudl ◽  
Robert Stojan ◽  
Claudia Voelcker-Rehage

Numerous studies have reported the beneficial effects of acute exercise on executive functions. Less is known, however, about the effects of exercise on working memory as one subcomponent of executive functions and about its effects on older adults. We investigated the effects of acute moderate-intensity exercise on working memory performance, the respective cortical hemodynamic activation patterns, and the development and persistence of such effects in healthy older adults. Forty-four participants (M: 69.18 years ± 3.92; 21 females) performed a letter 2-back task before and at three time points after (post 15 min, post 30 min, and post 45 min) either listening to an audiobook or exercising (15 min; 50% VO2-peak). Functional near-infrared spectroscopy (fNIRS) was used to assess cortical hemodynamic activation and brain-behavior correlations in the fronto-parietal working memory network. Overall, we found no group differences for working memory performance. However, only within the experimental group, 2-back performance was enhanced 15 min and 45 min post-exercise. Furthermore, 15 min post-exercise frontal activation predicted working memory performance, regardless of group. In sum, our results indicate slight beneficial effects of acute moderate-intensity exercise on working memory performance in healthy older adults. Findings are discussed in light of the cognitive aging process and moderators affecting the exercise-cognition relationship.


2010 ◽  
Vol 35 (5) ◽  
pp. 583-590 ◽  
Author(s):  
Cheryl Murphy ◽  
Benjamin F. Miller

Research measuring whole-body protein turnover (WBPT) after both exercise and nutrition has generally focused on resistance exercise; however, there is a paucity of data regarding the effect of postaerobic exercise nutrition, especially in older adults. It is not known if postexercise protein feeding has a beneficial effect on protein turnover after low- to moderate-intensity exercise. We investigated whether consuming protein plus carbohydrate (PRO) immediately after an acute bout of aerobic exercise has an additive effect over carbohydrate alone (CHO) on WBPT in older individuals. Twelve healthy older adults (age, 59 ± 4 years) were studied on 2 separate occasions after 1 h of exercise at approximately 50% of maximal rate of oxygen uptake, followed by 4 h of recovery. Immediately following exercise, subjects ingested a CHO (60 g) or an isocaloric PRO beverage (40 g carbohydrate, 20 g whey protein). Whole-body protein metabolism was determined using [1-13C]leucine infusion (60 mg prime; 75 mg·h–1 continuous), and sampling blood and expired breath. Rates of whole-body leucine appearance and oxidation, and nonoxidative leucine disposal during the third and fourth hours of postexercise recovery were higher in the PRO group (2.51 ± 0.55, 0.78 ± 0.37, and 1.71 ± 0.44 µmol·kg–1·min–1, respectively) than in the CHO group (1.81 ± 0.27, 0.33 ± 0.14, and 1.47 ± 0.25 µmol·kg–1·min–1, respectively; p = 0.001). Our results indicate that consumption of a PRO beverage after aerobic exercise increased WBPT to a greater extent than a CHO beverage.


2020 ◽  
Vol 127 (5) ◽  
pp. 823-840
Author(s):  
Ligita Siline ◽  
Arvydas Stasiulis ◽  
Loreta Stasiule

The present study aimed to examine relationships between executive function (EF) and variables of aerobic fitness. Participants were 32 healthy older adults ( M age = 65.1, SD = 6.6 years). We measured the first ventilatory threshold (VeT1) and the kinetics of oxygen uptake ([Formula: see text]O2), heart rate (HR), and muscle deoxygenation [HHb] during treadmill walking of either constant, moderate intensity, or increasing intensity. We assessed EF with a computerized Stroop test and Stroop measures of correct answers, reaction time, and percent interference. We found the Stroop interference score to be negatively associated with the VeT1 ( r = –0.387, p = 0.031) and positively associated with the on-transition aerobic metabolism time constant (τ) of HR ( r = 0.519, p = 0.003), [Formula: see text]O2 ( r = 0.454; p = 0.010), and [HHb] ( r = 0.644, p = 0.001). Correct responses were negatively related with τHR ( r = –0.372, p = 0.039) and τ[Formula: see text]O2 ( r = –0.500, p = 0.004). The Stroop average reaction time, congruent reaction time and incongruent reaction time were positively related to τ[HHb] ( r = 0.507, p = 0.010; r = 0.437, p = 0.029; r = 0.558, p = 0.004, respectively). Better EF was associated with faster on-transition aerobic metabolism and higher aerobic fitness among older adults.


2000 ◽  
Vol 88 (5) ◽  
pp. 1650-1658 ◽  
Author(s):  
B. D. Johnson ◽  
K. C. Beck ◽  
D. N. Proctor ◽  
J. Miller ◽  
N. M. Dietz ◽  
...  

An open-circuit (OpCirc) acetylene uptake cardiac output (Q˙t) method was modified for use during exercise. Two computational techniques were used. OpCirc1 was based on the integrated uptake vs. end-tidal change in acetylene, and OpCirc2 was based on an iterative finite difference modeling method. Six subjects [28–44 yr, peak oxygen consumption (V˙o 2) = 120% predicted] performed cycle ergometry exercise to compareQ˙t using OpCirc and direct Fick methods. An incremental protocol was repeated twice, separated by a 10-min rest, and subsequently subjects exercised at 85–90% of their peak work rate. Coefficient of variation of the OpCirc methods and Fick were highest at rest (OpCirc1, 7%, OpCirc2, 12%, Fick, 10%) but were lower at moderate to high exercise intensities (OpCirc1, 3%, OpCirc2, 3%, Fick, 5%). OpCirc1 and OpCirc2 Q˙t correlated highly with Fick Q˙t( R 2 = 0.90 and 0.89, respectively). There were minimal differences between OpCirc1 and OpCirc2 compared with Fick up to moderate-intensity exercise (<70% peakV˙o 2); however, both techniques tended to underestimate Fick at >70% peakV˙o 2. These differences became significant for OpCirc1 only. Part of the differences between Fick and OpCirc methods at the higher exercise intensities are likely related to inhomogeneities in ventilation and perfusion matching ( R 2 = 0.36 for Fick − OpCirc1 vs. alveolar-to-arterial oxygen tension difference). In conclusion, both OpCirc methods provided reproducible, reliable measurements ofQ˙t during mild to moderate exercise. However, only OpCirc2 appeared to approximate FickQ˙t at the higher work intensities.


2019 ◽  
Vol 54 (13) ◽  
pp. 776-781 ◽  
Author(s):  
Michael J Wheeler ◽  
Daniel J Green ◽  
Kathryn A Ellis ◽  
Ester Cerin ◽  
Ilkka Heinonen ◽  
...  

BackgroundSedentary behaviour is associated with impaired cognition, whereas exercise can acutely improve cognition.ObjectiveWe compared the effects of a morning bout of moderate-intensity exercise, with and without subsequent light-intensity walking breaks from sitting, on cognition in older adults.MethodsSedentary overweight/obese older adults with normal cognitive function (n=67, 67±7 years, 31.2±4.1 kg/m2) completed three conditions (6-day washout): SIT (sitting): uninterrupted sitting (8 hours, control); EX+SIT (exercise + sitting): sitting (1 hour), moderate-intensity walking (30 min), uninterrupted sitting (6.5 hours); and EX+BR (exercise + breaks): sitting (1 hour), moderate-intensity walking (30 min), sitting interrupted every 30 min with 3 min of light-intensity walking (6.5 hours). Cognitive testing (Cogstate) was completed at four time points assessing psychomotor function, attention, executive function, visual learning and working memory. Serum brain-derived neurotrophic growth factor (BDNF) was assessed at six time points. The 8-hour net area under the curve (AUC) was calculated for each outcome.ResultsWorking memory net AUC z-score·hour (95% CI) was improved in EX+BR with a z-score of +28 (−26 to +81), relative to SIT, −25 (−79 to +29, p=0.04 vs EX+BR). Executive function net AUC was improved in EX+SIT, −8 (− 71 to +55), relative to SIT, −80 (−142 to −17, p=0.03 vs EX+SIT). Serum BDNF net AUC ng/mL·hour (95% CI) was increased in both EX+SIT, +171 (−449 to +791, p=0.03 vs SIT), and EX+BR, +139 (−481 to +759, p=0.045 vs SIT), relative to SIT, −227 (−851 to +396).ConclusionA morning bout of moderate-intensity exercise improves serum BDNF and working memory or executive function in older adults, depending on whether or not subsequent sitting is also interrupted with intermittent light-intensity walking.Trial registration numberACTRN12614000737639.


2020 ◽  
Vol 6 (1) ◽  
pp. e000672 ◽  
Author(s):  
Karani Magutah ◽  
Kihumbu Thairu ◽  
Nilesh Patel

AimTo investigate effect of <10 min moderate intensity exercise on cardiovascular function and maximal oxygen consumption (V˙ O2max) among sedentary adults.MethodsWe studied 53 sedentary urbanites aged ≥50 years, randomised into: (1) male (MS) and (2) female (FS) undertaking three short-duration exercise (5–10 min) daily, and (3) male (ML) and (4) female (FL) exercising 30–60 min 3–5 days weekly. Resting systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate and V˙ O2max were measured at baseline and 8 weekly for 24 weeks.ResultsAt baseline, 50% MS, 61.5% ML, 53.8% FS and 53.8% FL had SBP ≥120 mm Hg, and 14.3% MS, 53.8% ML, 23.1% FS and 38.5% FL had DBP ≥80 mm Hg. At 24 weeks, where SBP remained ≥120 mm Hg, values decreased from 147±19.2 to 132.3±9.6 mm Hg (50% of MS), from 144±12.3 to 128±7.0 mm Hg (23.1% of ML), from 143.1±9.6 to 128.0±7.0 mm Hg (53.8% of FS) and from 152.3±23.7 to 129±3.7 mm Hg (30.8% of FL). For DBP ≥80 mm Hg, MS and FS percentages maintained, but values decreased from 101±15.6 to 84.5±0.7 mm Hg (MS) and 99.0±3.6 to 87.7±4.9 mm Hg (FS). In ML and FL, percentage with DBP ≥80 mm Hg dropped to 15.4% (86.1±6.5 to 82.5±3.5 mm Hg) and (91.4±5.3 to 83.5±0.71 mm Hg). V˙ O2max increased from 26.1±4.4 to 32.0±6.2 for MS, from 25.8±5.1 to 28.8±5.4 for ML (group differences p=0.02), from 20.2±1.8 to 22.7±2.0 for FS and from 21.2±1.9 to 24.2±2.7 for FL (groups differences p=0.38).ConclusionAccumulated moderate intensity exercise bouts of <10 min confer similar-to-better cardiovascular and V˙ O2max improvements compared with current recommendations among sedentary adults.


2008 ◽  
Vol 294 (2) ◽  
pp. R577-R584 ◽  
Author(s):  
B. J. Gurd ◽  
S. J. Peters ◽  
G. J. F. Heigenhauser ◽  
P. J. LeBlanc ◽  
T. J. Doherty ◽  
...  

The adaptation of pulmonary O2 uptake (V̇o2p) kinetics is slowed in older compared with young adults during the transition to moderate-intensity exercise. In this study, we examined the relationship between V̇o2p kinetics and mitochondrial pyruvate dehydrogenase (PDH) activity in young ( n = 7) and older ( n = 6) adults. Subjects performed cycle exercise to a work rate corresponding to ∼90% of estimated lactate threshold. Phase 2 V̇o2p kinetics were slower ( P < 0.05) in older (τ = 40 ± 17 s) compared with young (τ = 21 ± 6 s) adults. Relative phosphocreatine (PCr) breakdown was greater ( P < 0.05) at 30 s in older compared with young adults. Absolute PCr breakdown at 6 min was greater ( P < 0.05) in older compared with young adults. In young adults, PDH activity increased ( P < 0.05) from baseline to 30 s, with no further change observed at 6 min. In older adults, PDH activity during baseline exercise was similar to that seen in young adults. During the exercise transition, PDH activity did not increase ( P > 0.05) at 30 s of exercise but was elevated ( P < 0.05) after 6 min. The change in deoxyhemoglobin (HHb) was greater for a given V̇o2p in older adults, and there was a similar time course of HHb accompanying the slower V̇o2p kinetics in the older adults, suggesting a slower adaptation of bulk O2 delivery in older adults. In conclusion, the slower adaptation of V̇o2p in older adults is likely a result of both an increased metabolic inertia and lower O2 availability.


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