Dataset Information

Influence of exercise duration on cardiorespiratory responses, energy cost and tissue oxygenation within a 6 hour treadmill run.

ABSTRACT: PURPOSE:The physiological mechanisms for alterations in oxygen utilization ([Formula: see text]) and the energy cost of running (Cr ) during prolonged running are not completely understood, and could be linked with alterations in muscle and cerebral tissue oxygenation. METHODS:Eight trained ultramarathon runners (three women; mean ± SD; age 37 ± 7 yr; maximum [Formula: see text] 60 ± 15 mL min-1 kg-1) completed a 6 hr treadmill run (6TR), which consisted of four modules, including periods of moderate (3 min at 10 km h-1, 10-CR) and heavy exercise intensities (6 min at 70% of maximum [Formula: see text], HILL), separated by three, 100 min periods of self-paced running (SP). We measured [Formula: see text], minute ventilation ([Formula: see text]), ventilatory efficiency ([Formula: see text]), respiratory exchange ratio (RER), Cr , muscle and cerebral tissue saturation index (TSI) during the modules, and heart rate (HR) and perceived exertion (RPE) during the modules and SP. RESULTS:Participants ran 58.3 ± 10.5 km during 6TR. Speed decreased and HR and RPE increased during SP. Across the modules, HR and [Formula: see text] increased (10-CR), and RER decreased (10-CR and HILL). There were no significant changes in [Formula: see text], [Formula: see text], Cr , TSI and RPE across the modules. CONCLUSIONS:In the context of positive pacing (decreasing speed), increased cardiac drift and perceived exertion over the 6TR, we observed increased RER and increased HR at moderate and heavy exercise intensity, increased [Formula: see text] at moderate intensity, and no effect of exercise duration on ventilatory efficiency, energy cost of running and tissue oxygenation.

SUBMITTER: Kerherve HA

PROVIDER: S-EPMC5637745 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Influence of exercise duration on cardiorespiratory responses, energy cost and tissue oxygenation within a 6 hour treadmill run.

Kerhervé Hugo A HA McLean Scott S Birkenhead Karen K Parr David D Solomon Colin C

PeerJ 20171009

<h4>Purpose</h4>The physiological mechanisms for alterations in oxygen utilization ([Formula: see text]) and the energy cost of running (<i>C</i><sub><i>r</i></sub> ) during prolonged running are not completely understood, and could be linked with alterations in muscle and cerebral tissue oxygenation.<h4>Methods</h4>Eight trained ultramarathon runners (three women; mean ± SD; age 37 ± 7 yr; maximum [Formula: see text] 60 ± 15 mL min<sup>-1</sup> kg<sup>-1</sup>) completed a 6 hr treadmill run (6 ...[more]

PMID: 29038746

Similar Datasets

Project description:ImportanceAdverse cardiovascular findings associated with habitual vigorous exercise have raised new questions regarding the benefits of exercise and fitness.ObjectiveTo assess the association of all-cause mortality and cardiorespiratory fitness in patients undergoing exercise treadmill testing.Design, setting, and participantsThis retrospective cohort study enrolled patients at a tertiary care academic medical center from January 1, 1991, to December 31, 2014, with a median follow-up of 8.4 years. Data analysis was performed from April 19 to July 17, 2018. Consecutive adult patients referred for symptom-limited exercise treadmill testing were stratified by age- and sex-matched cardiorespiratory fitness into performance groups: low (<25th percentile), below average (25th-49th percentile), above average (50th-74th percentile), high (75th-97.6th percentile), and elite (?97.7th percentile).ExposuresCardiorespiratory fitness, as quantified by peak estimated metabolic equivalents on treadmill testing.Main outcomes and measuresAll-cause mortality.ResultsThe study population included 122?007 patients (mean [SD] age, 53.4?[12.6] years; 72 173 [59.2%] male). Death occurred in 13?637 patients during 1.1 million person-years of observation. Risk-adjusted all-cause mortality was inversely proportional to cardiorespiratory fitness and was lowest in elite performers (elite vs low: adjusted hazard ratio [HR], 0.20; 95% CI, 0.16-0.24; P?<?.001; elite vs high: adjusted HR, 0.77; 95% CI, 0.63-0.95; P?=?.02). The increase in all-cause mortality associated with reduced cardiorespiratory fitness (low vs elite: adjusted HR, 5.04; 95% CI, 4.10-6.20; P?<?.001; below average vs above average: adjusted HR, 1.41; 95% CI, 1.34-1.49; P?<?.001) was comparable to or greater than traditional clinical risk factors (coronary artery disease: adjusted HR, 1.29; 95% CI, 1.24-1.35; P?<?.001; smoking: adjusted HR, 1.41; 95% CI, 1.36-1.46; P?<?.001; diabetes: adjusted HR, 1.40; 95% CI, 1.34-1.46; P?<?.001). In subgroup analysis, the benefit of elite over high performance was present in patients 70 years or older (adjusted HR, 0.71; 95% CI, 0.52-0.98; P?=?.04) and patients with hypertension (adjusted HR, 0.70; 95% CI, 0.50-0.99; P?=?.05). Extreme cardiorespiratory fitness (?2 SDs above the mean for age and sex) was associated with the lowest risk-adjusted all-cause mortality compared with all other performance groups.Conclusions and relevanceCardiorespiratory fitness is inversely associated with long-term mortality with no observed upper limit of benefit. Extremely high aerobic fitness was associated with the greatest survival and was associated with benefit in older patients and those with hypertension. Cardiorespiratory fitness is a modifiable indicator of long-term mortality, and health care professionals should encourage patients to achieve and maintain high levels of fitness.

Project description:BackgroundInclined walking requires more cardiopulmonary metabolic energy and muscle strength than flat-level walking. This study sought to investigate changes in lower-limb muscle activity and cardiopulmonary metabolic energy cost during treadmill walking with different inclination grades and to discern any correlation between these two measures in older adults.MethodsTwenty-four healthy older adults (n = 11 males; mean age: 75.3 ± 4.0 years) participated. All participants walked on a treadmill that was randomly inclined at 0% (condition 1), 10% (condition 2), and 16% (condition 3) for five minutes each. Simultaneous measurements of lower-limb muscle activity and cardiopulmonary metabolic energy cost during inclined treadmill walking were collected. Measured muscles included the rectus abdominis (RA), erector spinae (ES), rectus femoris (RF), biceps femoris (BF), vastus medialis (VM), tibialis anterior (TA), medial head of the gastrocnemius (GCM), and soleus (SOL) muscles on the right side.ResultsAs compared with 0% inclined treadmill gait, the 10% inclined treadmill gait increased the net cardiopulmonary metabolic energy cost by 22.9%, while the 16% inclined treadmill gait increased the net cardiopulmonary metabolic energy cost by 44.2%. In the stance phase, as the slope increased, activity was significantly increased in the RA, RF, VM, BF, GCM, and SOL muscles. In the swing phase, As the slope increased activity was significantly increased in the RA, RF, VM, BF, and TA muscles. SOL muscle activity was most relevant to the change in cardiopulmonary metabolic energy cost in the stance phase of inclined treadmill walking. The relationship between the increase in cardiopulmonary metabolic energy cost and changes in muscle activity was also significant in the VM, GCM, and RF.ConclusionThis study demonstrated that changes in SOL, VM, GCM, and RA muscle activity had a significant relationship with cardiopulmonary metabolic energy cost increment during inclined treadmill walking. These results can be used as basic data for various gait-training programs and as an indicator in the development of assistive algorithms of wearable walking robots for older adults.Trial registrationClinical trials registration information: ClinicalTrials.gov Identifier: NCT04614857 (05/11/2020).

Project description:Emerging evidence identifies a potent role for aerobic exercise to modulate activity of neurons involved in regulating appetite; however, these studies produce conflicting results. These discrepancies may be, in part, due to methodological differences, including differences in exercise intensity and pre-exercise energy status. Consequently, the current study utilized a translational, well-controlled, within-subject, treadmill exercise protocol to investigate the differential effects of energy status and exercise intensity on post-exercise feeding behavior and appetite-controlling neurons in the hypothalamus. Mature, untrained male mice were exposed to acute sedentary, low (10m/min), moderate (14m/min), and high (18m/min) intensity treadmill exercise in a randomized crossover design. Fed and 10-hour-fasted mice were used, and food intake was monitored 48h. post-exercise. Immunohistochemical detection of cFOS was performed 1-hour post-exercise to determine changes in hypothalamic NPY/AgRP, POMC, tyrosine hydroxylase, and SIM1-expressing neuron activity concurrent with changes in food intake. Additionally, stains for pSTAT3tyr705 and pERKthr202/tyr204 were performed to detect exercise-mediated changes in intracellular signaling. Results demonstrated that fasted high intensity exercise suppressed food intake compared to sedentary trials, which was concurrent with increased anorexigenic POMC neuron activity. Conversely, fed mice experienced augmented post-exercise food intake, with no effects on POMC neuron activity. Regardless of pre-exercise energy status, tyrosine hydroxylase and SIM1 neuron activity in the paraventricular nucleus was elevated, as well as NPY/AgRP neuron activity in the arcuate nucleus. Notably, these neuronal changes were independent from changes in pSTAT3tyr705 and pERKthr202/tyr204 signaling. Overall, these results suggest fasted high intensity exercise may be beneficial for suppressing food intake, possibly due to hypothalamic POMC neuron excitation. Furthermore, this study identifies a novel role for pre-exercise energy status to differentially modify post-exercise feeding behavior and hypothalamic neuron activity, which may explain the inconsistent results from studies investigating exercise as a weight loss intervention.

Project description:Kenneth Gillingham is an Associate Professor of Economics at Yale University, with a primary appointment in the School of Forestry & Environmental Studies. In 2015 to 2016, he served as the Senior Economist for Energy and the Environment at the White House Council of Economic Advisers. His research interests cover energy and environmental economics, industrial organization, technological change, and energy modeling. He held a Fulbright to New Zealand and has worked for Resources for the Future and Pacific Northwest National Laboratory. He received a PhD and two MS degrees from Stanford University and an AB from Dartmouth College. Christopher Knittel is the George P. Shultz Professor of Applied Economics in the Sloan School of Management at the Massachusetts Institute of Technology (MIT). He is also the Director of MIT's Center for Energy and Environmental Policy Research, which serves as the hub for social science research on energy and the environmental since the late 1970s. Professor Knittel is also the Co-Director of the MIT Energy Initiative's Electric Power System Low Carbon Energy Center and a co-director of The E2e Project, a research initiative between MIT, UC Berkeley, and the University of Chicago to undertake rigorous evaluation of energy efficiency investments. Jing Li holds the inaugural William Barton Rogers Career Development Chair of Energy Economics at the MIT Sloan School of Management. From 2017-2018, Jing Li was a Postdoctoral Associate of the MIT Energy Initiative. Jing's research interests lie in energy economics and industrial organization, focusing on development and adoption of new technologies. Her most recent work examines compatibility and investment in electric vehicle recharging networks in the United States and cost pass-through in the E85 retail market. Jing received double BSc degrees in Mathematics and Economics from MIT in 2011 and her PhD in Economics from Harvard in 2017. Marten Ovaere is a Postdoctoral Associate in the School of Forestry & Environmental Studies of Yale University. His research interests lie in energy and environmental economics, with a focus on electricity markets, carbon pricing, and renewable energy. Marten holds a MSc in Economics, a MSc in Energy Engineering, and a PhD in Economics from KU Leuven. Mar Reguant is an Associate Professor in Economics at Northwestern University. She received her PhD from MIT in 2011. Her research uses high-frequency data to study the impact of auction design and environmental regulation on electricity markets and energy-intensive industries. She has numerous awards, including a Sloan Research Fellowship in 2016, the Sabadell Prize for Economic Research in 2017, a Presidential Early Career Award for Scientists and Engineers award in 2019, and the European Association of Environmental and Resource Economists Award for Researchers in Environmental Economics under the Age of Forty in 2019.

Project description:To compare responses to a cardiopulmonary exercise test on land versus on an underwater treadmill, to assess the cardiorespiratory performance of coronary artery disease patients while immersed in warm water and to compare with the performance of healthy individuals.The sample population consisted of 40 subjects, which included 20 coronary artery disease patients aged 63.7±8.89 years old, functional class I and II, according to the New York Hearth Association, and 20 healthy subjects aged 64.7±7.09 years old. The statistical significances were calculated through an ANOVA test with a (1 - ?) power of 0.861. ClinicalTrials.gov: NCT00989248 (22).Significant differences were uncovered in coronary artery disease group regarding the variables heart beats (HB), (p>0.01), oxygen consumption (VO2), (p>0.01) and carbon dioxide production (VCO2) (p<0.01). Also, for the same group, in relation to the environment, water versus on land for HB, VO2, VCO2 and oxygen for each heart beat (VO2/HB) all of than (p<0.01). The stages for data collected featured the subject's performance throughout the experiment, and within the given context, variables rating of perceived exertion (RPE), HB, VO2, VCO2 and VO2/HB (p<0.01) showed significant interactions between test stages and environment. Additionally, there was a significant interaction between the etiology and the test stages for the variables HB, VO2 and VCO2 (p<0.01). Electrocardiographic changes compatible with myocardial ischemia or arrhythmia were not observed. The subjects exhibited lower scores on Borg's perceived exertion scale in the water than at every one of the test stages on land (p<0.01).This study show that a cardiopulmonary exercise test can be safely conducted in subjects in immersion and that the procedures, resources and equipment used yielded replicable and reliable data. Significant differences observed in water versus on land allow us to conclude that coronary artery disease patients are able to do physical exercise in water and that the physiological effects of immersion do not present any risk for such patients, as exercise was well tolerated by all subjects.

Dataset Information

Influence of exercise duration on cardiorespiratory responses, energy cost and tissue oxygenation within a 6 hour treadmill run.

Publications

Influence of exercise duration on cardiorespiratory responses, energy cost and tissue oxygenation within a 6 hour treadmill run.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure