Browsing by Subject "Oxygen Consumption"
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Item Open Access A Randomized Controlled Trial Investigating the Feasibility and Adherence to an Aerobic Training Program in Healthy Individuals.(Journal of sport rehabilitation, 2019-09) Teel, Elizabeth F; Marshall, Stephen W; Appelbaum, L Gregory; Battaglini, Claudio L; Carneiro, Kevin A; Guskiewicz, Kevin M; Register-Mihalik, Johna K; Mihalik, Jason PCONTEXT:Concussion management is moving from passive rest strategies to active interventions, including aerobic exercise therapy. Little information is available regarding the feasibility and adherence of these programs. OBJECTIVES:To determine whether an aerobic exercise training program intended for rehabilitation in people with concussion is feasible. Healthy, nonconcussed subjects were studied in this phase 1 trial. DESIGN:Phase 1 parallel-group, randomized controlled trial in a sample of healthy (nonconcussed), recreationally active university students. SETTING:Laboratory. PATIENTS:40 healthy university students. METHODS:Participants were equally randomized to acute concussion therapy intervention (ACTIVE) training or nontraining groups. All participants completed maximal cardiopulmonary exercise tests on a stationary cycle ergometer at 2 test sessions approximately 14 days apart. During this 2-week study period, ACTIVE training participants completed six 30-minute cycling sessions, progressing from 60% to 80% of the participant's individualized maximal oxygen consumption. A subset of participants (NACTIVE = 12, Nnontraining = 11) wore physical activity monitors throughout the 2-week study period. MAIN OUTCOMES MEASURES:Study protocol and randomization effectiveness, exercise safety and adherence, and progressive intensity of the ACTIVE training procedures. RESULTS:No adverse events occurred during any exercise sessions. Twelve ACTIVE training participants (60%) completed all training sessions, and every participant completed at least 4 sessions. Heart rate increased throughout the training period (P < .001), but symptom changes and training adherence remained stable despite the progressively increasing workload. ACTIVE training participants completed approximately 30 additional minutes of physical activity on training sessions days, although that was not statistically significant (P = .20). CONCLUSIONS:University-aged students were adherent to the ACTIVE training protocol. Future research should investigate the safety and feasibility of aerobic training programs in acutely concussed individuals to determine their appropriateness as a clinical rehabilitation strategy.Item Open Access Blood Pressure Response during Cardiopulmonary Exercise Testing in Heart Failure.(Medicine and science in sports and exercise, 2018-07) Il'giovine, Zachary J; Solomon, Nicole; Devore, Adam D; Wojdyla, Daniel; Patel, Chetan B; Rogers, Joseph GIntroduction
The prognostic value of peak V˙O2 and V˙E/V˙CO2 slope measured during cardiopulmonary exercise (CPX) testing has been well established in patients with advanced heart failure, but blood pressure response to exercise is less well characterized.Methods
We retrospectively studied 151 outpatients who underwent CPX testing as part of an advanced heart failure evaluation. The outcome of interest was failure of medical management, defined by death, cardiac transplantation, or left ventricular assist device placement. Patients were stratified into tertiles by change in systolic blood pressure (SBP) (<13, 13-26, and ≥27 mm Hg) during exercise.Results
Patients in the lowest tertile had the lowest peak V˙O2 (10.2 vs 10.6 vs 13.6 mL·kg·min, P = <0.001), the highest V˙E/V˙CO2 slope (42.8 vs 42.1 vs 36.3, P = 0.030), the shortest mean exercise time (5.1 vs 6.0 vs 7.0 min, P = <0.001), and the highest probability of failure of medical management at 1.5 yr (0.69 vs 0.41 vs 0.34, P = 0.011). After multivariate adjustment, increased SBP <20 mm Hg during exercise was associated with a lower hazard of medical management failure (hazard ratio = 0.96, 95% confidence interval [CI] = 0.934-0.987), whereas SBP increases >20 mm Hg were associated with an increased hazard (hazard ratio = 1.046, 95% CI = 1.018-1.075).Conclusion
In conclusion, changes in SBP during CPX testing provide additional prognostic information above standard clinical variables. The peculiar increase in risk noted in those with a rise in SBP >20 mm Hg is less clear and needs to be investigated further.Item Open Access Cardiorespiratory fitness and cognitive function in midlife: neuroprotection or neuroselection?(Ann Neurol, 2015-04) Belsky, Daniel W; Caspi, Avshalom; Israel, Salomon; Blumenthal, James A; Poulton, Richie; Moffitt, Terrie EOBJECTIVE: A study was undertaken to determine whether better cognitive functioning at midlife among more physically fit individuals reflects neuroprotection, by which fitness protects against age-related cognitive decline, or neuroselection, by which children with higher cognitive functioning select more active lifestyles. METHODS: Children in the Dunedin Longitudinal Study (N = 1,037) completed the Wechsler Intelligence Scales and the Trail Making, Rey Delayed Recall, and Grooved Pegboard tasks as children and again at midlife (age = 38 years). Adult cardiorespiratory fitness was assessed using a submaximal exercise test to estimate maximum oxygen consumption adjusted for body weight in milliliters/minute/kilogram. We tested whether more fit individuals had better cognitive functioning than their less fit counterparts (which could be consistent with neuroprotection), and whether better childhood cognitive functioning predisposed to better adult cardiorespiratory fitness (neuroselection). Finally, we examined possible mechanisms of neuroselection. RESULTS: Participants with better cardiorespiratory fitness had higher cognitive test scores at midlife. However, fitness-associated advantages in cognitive functioning were already present in childhood. After accounting for childhood baseline performance on the same cognitive tests, there was no association between cardiorespiratory fitness and midlife cognitive functioning. Socioeconomic and health advantages in childhood and healthier lifestyles during young adulthood explained most of the association between childhood cognitive functioning and adult cardiorespiratory fitness. INTERPRETATION: We found no evidence for a neuroprotective effect of cardiorespiratory fitness as of midlife. Instead, children with better cognitive functioning are selecting healthier lives. Fitness interventions may enhance cognitive functioning. However, observational and experimental studies testing neuroprotective effects of physical fitness should consider confounding by neuroselection.Item Open Access Cell cycle Start is coupled to entry into the yeast metabolic cycle across diverse strains and growth rates.(Mol Biol Cell, 2016-01-01) Burnetti, Anthony J; Aydin, Mert; Buchler, Nicolas ECells have evolved oscillators with different frequencies to coordinate periodic processes. Here we studied the interaction of two oscillators, the cell division cycle (CDC) and the yeast metabolic cycle (YMC), in budding yeast. Previous work suggested that the CDC and YMC interact to separate high oxygen consumption (HOC) from DNA replication to prevent genetic damage. To test this hypothesis, we grew diverse strains in chemostat and measured DNA replication and oxygen consumption with high temporal resolution at different growth rates. Our data showed that HOC is not strictly separated from DNA replication; rather, cell cycle Start is coupled with the initiation of HOC and catabolism of storage carbohydrates. The logic of this YMC-CDC coupling may be to ensure that DNA replication and cell division occur only when sufficient cellular energy reserves have accumulated. Our results also uncovered a quantitative relationship between CDC period and YMC period across different strains. More generally, our approach shows how studies in genetically diverse strains efficiently identify robust phenotypes and steer the experimentalist away from strain-specific idiosyncrasies.Item Open Access Commentary: The heart of the matter: Close clinical follow-up and exercise capacity in Fontan circulation.(The Journal of thoracic and cardiovascular surgery, 2021-08) Well, Andrew; Beckerman, ZivItem Open Access Randomized Controlled Trial Evaluating Aerobic Training and Common Sport-Related Concussion Outcomes in Healthy Participants.(Journal of athletic training, 2018-12-18) Teel, Elizabeth F; Register-Mihalik, Johna K; Appelbaum, Lawrence Gregory; Battaglini, Claudio L; Carneiro, Kevin A; Guskiewicz, Kevin M; Marshall, Stephen W; Mihalik, Jason PCONTEXT:Aerobic exercise interventions are increasingly being prescribed for concussion rehabilitation, but whether aerobic training protocols influence clinical concussion diagnosis and management assessments is unknown. OBJECTIVE:To investigate the effects of a brief aerobic exercise intervention on clinical concussion outcomes in healthy, active participants. DESIGN:Randomized controlled clinical trial. SETTING:Laboratory. PATIENTS OR OTHER PARTICIPANTS:Healthy (uninjured) participants (n = 40) who exercised ≥3 times/week. INTERVENTION(S):Participants were randomized into the acute concussion therapy intervention (ACTIVE) training or nontraining group. All participants completed symptom, cognitive, balance, and vision assessments during 2 test sessions approximately 14 days apart. Participants randomized to ACTIVE training completed six 30-minute exercise sessions that progressed from 60% to 80% of individualized maximal oxygen consumption (V˙o2max) across test sessions, while the nontraining group received no intervention. MAIN OUTCOME MEASURE(S):The CNS Vital Signs standardized scores, Vestibular/Ocular Motor Screening near-point convergence distance (cm), and Graded Symptom Checklist, Balance Error Scoring System, and Standardized Assessment of Concussion total scores. RESULTS:An interaction effect was found for total symptom score ( P = .01); the intervention group had improved symptom scores between sessions (session 1: 5.1 ± 5.8; session 2: 1.9 ± 3.6). Cognitive flexibility, executive functioning, reasoning, and total symptom score outcomes were better but composite memory, verbal memory, and near-point convergence distance scores were worse at the second session (all P values < .05). However, few changes exceeded the 80% reliable change indices calculated for this study, and effect sizes were generally small to negligible. CONCLUSIONS:A brief aerobic training protocol had few meaningful effects on clinical concussion assessment in healthy participants, suggesting that current concussion-diagnostic and -assessment tools remain clinically stable in response to aerobic exercise training. This provides normative data for future researchers, who should further evaluate the effect of ACTIVE training on clinical outcomes among concussed populations. TRIAL REGISTRATION NUMBER:ClinicalTrials.gov : NCT02872480.Item Restricted Rationale and design of the Exercise Intensity Trial (EXCITE): A randomized trial comparing the effects of moderate versus moderate to high-intensity aerobic training in women with operable breast cancer.(BMC Cancer, 2010-10-06) Jones, Lee W; Douglas, Pamela S; Eves, Neil D; Marcom, P Kelly; Kraus, William E; Herndon, James E; Inman, Brant A; Allen, Jason D; Peppercorn, JeffreyBACKGROUND: The Exercise Intensity Trial (EXcITe) is a randomized trial to compare the efficacy of supervised moderate-intensity aerobic training to moderate to high-intensity aerobic training, relative to attention control, on aerobic capacity, physiologic mechanisms, patient-reported outcomes, and biomarkers in women with operable breast cancer following the completion of definitive adjuvant therapy. METHODS/DESIGN: Using a single-center, randomized design, 174 postmenopausal women (58 patients/study arm) with histologically confirmed, operable breast cancer presenting to Duke University Medical Center (DUMC) will be enrolled in this trial following completion of primary therapy (including surgery, radiation therapy, and chemotherapy). After baseline assessments, eligible participants will be randomized to one of two supervised aerobic training interventions (moderate-intensity or moderate/high-intensity aerobic training) or an attention-control group (progressive stretching). The aerobic training interventions will include 150 mins.wk⁻¹ of supervised treadmill walking per week at an intensity of 60%-70% (moderate-intensity) or 60% to 100% (moderate to high-intensity) of the individually determined peak oxygen consumption (VO₂peak) between 20-45 minutes/session for 16 weeks. The progressive stretching program will be consistent with the exercise interventions in terms of program length (16 weeks), social interaction (participants will receive one-on-one instruction), and duration (20-45 mins/session). The primary study endpoint is VO₂peak, as measured by an incremental cardiopulmonary exercise test. Secondary endpoints include physiologic determinants that govern VO₂peak, patient-reported outcomes, and biomarkers associated with breast cancer recurrence/mortality. All endpoints will be assessed at baseline and after the intervention (16 weeks). DISCUSSION: EXCITE is designed to investigate the intensity of aerobic training required to induce optimal improvements in VO₂peak and other pertinent outcomes in women who have completed definitive adjuvant therapy for operable breast cancer. Overall, this trial will inform and refine exercise guidelines to optimize recovery in breast and other cancer survivors following the completion of primary cytotoxic therapy. TRIAL REGISTRATION: NCT01186367.Item Open Access Swimming-Induced Pulmonary Edema: Pathophysiology and Risk Reduction With Sildenafil.(Circulation, 2016-03-08) Moon, RE; Peacher, DF; Potter, JF; Wester, TE; Cherry, AD; Natoli, M; Otteni, CE; Kernagis, DN; White, WD; Freiberger, JBACKGROUND: Swimming-induced pulmonary edema (SIPE) occurs during swimming or scuba diving, often in young individuals with no predisposing conditions, and its pathophysiology is poorly understood. This study tested the hypothesis that pulmonary artery and pulmonary artery wedge pressures are higher in SIPE-susceptible individuals during submerged exercise than in the general population and are reduced by sildenafil. METHODS AND RESULTS: Ten study subjects with a history of SIPE (mean age, 41.6 years) and 20 control subjects (mean age, 36.2 years) were instrumented with radial artery and pulmonary artery catheters and performed moderate cycle ergometer exercise for 6 to 7 minutes while submersed in 20°C water. SIPE-susceptible subjects repeated the exercise 150 minutes after oral administration of 50 mg sildenafil. Work rate and mean arterial pressure during exercise were similar in controls and SIPE-susceptible subjects. Average o2 and cardiac output in controls and SIPE-susceptible subjects were: o2 2.42 L·min(-1) versus 1.95 L·min(-1), P=0.2; and cardiac output 17.9 L·min(-1) versus 13.8 L·min(-1), P=0.01. Accounting for differences in cardiac output between groups, mean pulmonary artery pressure at cardiac output=13.8 L·min(-1) was 22.5 mm Hg in controls versus 34.0 mm Hg in SIPE-susceptible subjects (P=0.004), and the corresponding pulmonary artery wedge pressure was 11.0 mm Hg versus 18.8 mm Hg (P=0.028). After sildenafil, there were no statistically significant differences in mean pulmonary artery pressure or pulmonary artery wedge pressure between SIPE-susceptible subjects and controls. CONCLUSIONS: These observations confirm that SIPE is a form of hemodynamic pulmonary edema. The reduction in pulmonary vascular pressures after sildenafil with no adverse effect on exercise hemodynamics suggests that it may be useful in SIPE prevention. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00815646.Item Open Access The lung cancer exercise training study: a randomized trial of aerobic training, resistance training, or both in postsurgical lung cancer patients: rationale and design.(BMC Cancer, 2010-04-21) Jones, Lee W; Eves, Neil D; Kraus, William E; Potti, Anil; Crawford, Jeffrey; Blumenthal, James A; Peterson, Bercedis L; Douglas, Pamela SBACKGROUND: The Lung Cancer Exercise Training Study (LUNGEVITY) is a randomized trial to investigate the efficacy of different types of exercise training on cardiorespiratory fitness (VO2peak), patient-reported outcomes, and the organ components that govern VO2peak in post-operative non-small cell lung cancer (NSCLC) patients. METHODS/DESIGN: Using a single-center, randomized design, 160 subjects (40 patients/study arm) with histologically confirmed stage I-IIIA NSCLC following curative-intent complete surgical resection at Duke University Medical Center (DUMC) will be potentially eligible for this trial. Following baseline assessments, eligible participants will be randomly assigned to one of four conditions: (1) aerobic training alone, (2) resistance training alone, (3) the combination of aerobic and resistance training, or (4) attention-control (progressive stretching). The ultimate goal for all exercise training groups will be 3 supervised exercise sessions per week an intensity above 70% of the individually determined VO2peak for aerobic training and an intensity between 60 and 80% of one-repetition maximum for resistance training, for 30-45 minutes/session. Progressive stretching will be matched to the exercise groups in terms of program length (i.e., 16 weeks), social interaction (participants will receive one-on-one instruction), and duration (30-45 mins/session). The primary study endpoint is VO2peak. Secondary endpoints include: patient-reported outcomes (PROs) (e.g., quality of life, fatigue, depression, etc.) and organ components of the oxygen cascade (i.e., pulmonary function, cardiac function, skeletal muscle function). All endpoints will be assessed at baseline and postintervention (16 weeks). Substudies will include genetic studies regarding individual responses to an exercise stimulus, theoretical determinants of exercise adherence, examination of the psychological mediators of the exercise - PRO relationship, and exercise-induced changes in gene expression. DISCUSSION: VO2peak is becoming increasingly recognized as an outcome of major importance in NSCLC. LUNGEVITY will identify the optimal form of exercise training for NSCLC survivors as well as provide insight into the physiological mechanisms underlying this effect. Overall, this study will contribute to the establishment of clinical exercise therapy rehabilitation guidelines for patients across the entire NSCLC continuum. TRIAL REGISTRATION: NCT00018255.