Exercise-Induced Changes in Compensatory Reserve and Heart Rate Complexity

BACKGROUND: Portable noninvasive Heart Rate Complexity (HRC) and Compensatory Reserve Measurement (CRM) monitors have been developed to triage supine combat casualties. Neither monitor has been tested in upright individuals during physical exercise. This study tests the hypothesis that exercise evokes proportional changes in HRC and CRM.METHODS: Two instruments monitored volunteers (9 civilian and 11 soldiers) from the Army Trauma Training Department (ATTD) before, during, and following physical exercise. One recorded heart rate (HR, bpm), cardiac output (CO, L · min−1), heart rate variability (HRV, root mean square of successive differences, ms), and HRC (Sample Entropy, unitless). The other recorded HR, pulse oximetry (Spo2, %), and CRM (%).RESULTS: Baseline HR, CO, HRV, HRC, and CRM averaged 72 ± 1 bpm, 5.6 ± 1.2 L · min−1, 48 ± 24 ms, 1.9 ± 0.5, and 85 ± 10% in seated individuals. Exercise evoked peak HR and CO at > 200% of baseline, while HRC and CRM were simultaneously decreased to minimums that were ≤ 50% of baseline (all P < 0.001). HRV changes were variable and unreliable. Spo2 remained consistently above 95%. During a 60 min recovery, HR and CRM returned to baseline on parallel tracks (t1/2=11 ± 8 and 18 ± 14 min), whereas HRC recovery was slower than either CRM or HR (t1/2=40 ± 18 min, both P < 0.05).DISCUSSION: Exercise evoked qualitatively similar changes in CRM and HRC. CRM recovered incrementally faster than HRC, suggesting that vasodilation, muscle pump, and respiration compensate faster than cardiac autonomic control in young, healthy volunteers. Both HRC and CRM appear to provide reliable, objective, and noninvasive metrics of human performance in upright exercising individuals.Mulder MB, Eidelson SA, Buzzelli MD, Gross KR, Batchinsky AI, Convertino VA, Schulman CI, Namias N, Proctor KG. Exercise-induced changes in compensatory reserve and heart rate complexity. Aerosp Med Hum Perform. 2019; 90(12):1009–1015.

Download Full-text

Physical Exercise-Induced Changes and Season-Associated Differences in the Pituitary-Ovarian Function of Runners and Joggers*

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jcem-60-3-416 ◽

1985 ◽

Vol 60 (3) ◽

pp. 416-422 ◽

Cited By ~ 38

Author(s):

HANNELE RONKAINEN ◽

ARTO PAKARINEN ◽

PERTTI KIRKINEN ◽

ANTTI KAUPPILA

Keyword(s):

Physical Exercise ◽

Ovarian Function ◽

Exercise Induced ◽

Induced Changes

Download Full-text

Abstract MP12: Proteomic Predictors Of High-density Lipoprotein Cholesterol Response To Regular Exercise

Circulation ◽

10.1161/circ.143.suppl_1.mp12 ◽

2021 ◽

Vol 143 (Suppl_1) ◽

Author(s):

Jacob L Barber ◽

Guoshuai Cai ◽

Jeremy M Robbins ◽

Robert E Gerszten ◽

Prashant Rao ◽

...

Keyword(s):

Root Mean Square Error ◽

Pathway Analysis ◽

Biological Pathways ◽

Regular Exercise ◽

Mean Square ◽

Lasso Regression ◽

Exercise Response ◽

Exercise Induced ◽

Induced Changes ◽

Response To Exercise

Introduction: Regular exercise beneficially increases plasma HDL-C levels at the group level. However, variation in individual HDL-C responses to exercise highlight a need for predictive biomarkers of exercise response. Hypothesis: We hypothesized that baseline abundance of circulating proteins is predictive of HDL-C response to exercise and that identified proteins are part of a complex biological network of exercise response. Methods: We measured over 5,000 circulating proteins using an aptamer-affinity based platform (SomaScan) in 667 black and white adults from the HERITAGE Family Study. Fasting plasma HDL-C was measured at baseline and following 20 weeks of supervised endurance exercise training. To predict exercise induced changes in HDL-C using baseline abundance of circulating proteins, models were created using LASSO regression and a 70/30 training test data split with 10-fold cross validation. Biological pathways, networks, and functions involving proteins identified in predictive modeling were investigated by ingenuity pathway analysis (IPA) and integrated molecular pathway level analysis (IMPaLA). Results: Regular exercise significantly increased HDL-C in the sample by 1.5 ± 4.6 mg/dL (p<0.0001), however marked inter-individual differences in response were present (range: -19.5 to +17.4 mg/dL). LASSO regression of circulating proteins only yielded a model of 120 proteins with similar but stronger predictive power to a model of 19 clinical traits (root mean square error = 4.52 and 5.3 mg/dL respectively). LASSO regression of both clinical and proteomic predictors resulted in a final model of baseline HDL-C and 116 circulating proteins, with an improved root mean square error of 4.11 mg/dL. Furthermore, this panel of 116 proteins was able to explain 40.0% of the variance in exercise induced changes in plasma HDL-C, while clinical predictors alone (including baseline HDL-C) explained only 3.9%. Pathway analysis of these 116 proteins identified several biological processes including pathways involved in the progression towards atherosclerosis, angiogenesis, mTOR signaling, and mitochondrial fatty acid synthesis. Conclusions: Circulating proteins may allow for prediction of exercise induced changes in HDL-C. Additionally, proteins predictive of HDL-C response to exercise are associated with important biological pathways and may provide insights into the molecular mechanisms of the benefits of regular exercise.

Download Full-text

Exploration of heart-rate complexity to determine the need for lifesaving interventions in combat casualties

Journal of Critical Care ◽

10.1016/j.jcrc.2008.03.013 ◽

2008 ◽

Vol 23 (2) ◽

pp. 265-266 ◽

Cited By ~ 2

Author(s):

Andriy Batchinsky ◽

Jose Salinas ◽

James Skinner ◽

Daniel Weiss ◽

Charles Wade ◽

...

Keyword(s):

Heart Rate ◽

Heart Rate Complexity ◽

Combat Casualties

Download Full-text

The contribution of preintervention blood pressure, VO2max, BMI, autonomic function and gender to exercise-induced changes in heart rate variability

British Journal of Sports Medicine ◽

10.1136/bjsports-2013-092428 ◽

2013 ◽

Vol 47 (9) ◽

pp. 575-578 ◽

Cited By ~ 3

Author(s):

Catharina C Grant ◽

Dina C Janse van Rensburg

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Heart Rate Variability ◽

Autonomic Function ◽

And Gender ◽

Exercise Induced ◽

Induced Changes

Download Full-text

Diagnostic value of combining heart rate recovery and P-wave changes with exercise-induced changes in the ST segments for prediction of myocardial ischaemia

Acta Cardiologica ◽

10.1080/ac.70.4.3094651 ◽

2015 ◽

Vol 70 (4) ◽

pp. 422-429 ◽

Cited By ~ 1

Author(s):

Ilhan Koyuncu ◽

Kamil Tuluce ◽

Selcen Yakar Tuluce ◽

Betul Koyuncu ◽

Mehmet Eyuboglu ◽

...

Keyword(s):

Heart Rate ◽

Myocardial Ischaemia ◽

Heart Rate Recovery ◽

Diagnostic Value ◽

P Wave ◽

Exercise Induced ◽

St Segments ◽

Induced Changes

Download Full-text

Heart Rate Complexity in US Army Forward Surgical Teams During Pre Deployment Training

Military Medicine ◽

10.1093/milmed/usz434 ◽

2019 ◽

Vol 185 (5-6) ◽

pp. e724-e733

Author(s):

Michelle B Mulder ◽

Matthew S Sussman ◽

Sarah A Eidelson ◽

Kirby R Gross ◽

Mark D Buzzelli ◽

...

Keyword(s):

Heart Rate ◽

Physical Exercise ◽

Health Care Systems ◽

Mass Casualty ◽

Future Health ◽

Us Army ◽

Non Invasive ◽

Postural Changes ◽

Surgical Teams ◽

Heart Rate Complexity

Abstract Introduction For trauma triage, the US Army has developed a portable heart rate complexity (HRC) monitor, which estimates cardiac autonomic input and the activity of the hypothalamic-pituitary-adrenal (HPA) axis. We hypothesize that autonomic/HPA stress associated with predeployment training in U.S. Army Forward Surgical Teams will cause changes in HRC. Materials and Methods A prospective observational study was conducted in 80 soldiers and 10 civilians at the U.S. Army Trauma Training Detachment. Heart rate (HR, b/min), cardiac output (CO, L/min), HR variability (HRV, ms), and HRC (Sample Entropy, unitless), were measured using a portable non-invasive hemodynamic monitor during postural changes, a mass casualty (MASCAL) situational training exercise (STX) using live tissue, a mock trauma (MT) STX using moulaged humans, and/or physical exercise. Results Baseline HR, CO, HRV, and HRC averaged 72 ± 11b/min, 5.6 ± 1.2 L/min, 48 ± 24 ms, and 1.9 ± 0.5 (unitless), respectively. Supine to sitting to standing caused minimal changes. Before the MASCAL or MT, HR and CO both increased to ~125% baseline, whereas HRV and HRC both decreased to ~75% baseline. Those values all changed an additional ~5% during the MASCAL, but an additional 10 to 30% during the MT. With physical exercise, HR and CO increased to >200% baseline, while HRV and HRC both decreased to 40 to 60% baseline; these changes were comparable to those caused by the MT. All the changes were P < 0.05. Conclusions Various forms of HPA stress during Forward Surgical Team STXs can be objectively quantitated continuously in real time with a portable non-invasive monitor. Differences from resting baseline indicate stress anticipating an impending STX whereas differences between average and peak responses indicate the relative stress between STXs. Monitoring HRC could prove useful to field commanders to rapidly and objectively assess the readiness status of troops during STXs or repeated operational missions. In the future, health care systems and regulatory bodies will likely be held accountable for stress in their trainees and/or obliged to develop wellness options and standardize efforts to ameliorate burnout, so HRC metrics might have a role, as well.

Download Full-text

Exercise-Induced Changes in Tumor Growth via Tumor Immunity

Sports ◽

10.3390/sports9040046 ◽

2021 ◽

Vol 9 (4) ◽

pp. 46

Author(s):

Polyxeni Spiliopoulou ◽

Maria Gavriatopoulou ◽

Efstathios Kastritis ◽

Meletios Athanasios Dimopoulos ◽

Gerasimos Terzis

Keyword(s):

Immune System ◽

Physical Exercise ◽

Tumor Growth ◽

Tumor Immunity ◽

Immune Cells ◽

Immune Cell ◽

Tumor Development ◽

Exercise Induced ◽

Induced Changes

Immunity in the tumor microenvironment plays a central role in tumor development. Cytotoxic immune cells act against tumors, while tumors manage to trigger immunosuppressive mechanisms for defense. One bout of physical exercise acutely regulates the immune system inducing short-term redistribution of immune cells among body organs. Repeated acute immune cell mobilization with continuing exercise training results in long-term adaptations. These long-term exercise-induced changes in the immune system arise both in healthy and in diseased populations, including cancer patients. Recent preclinical studies indicate that physical exercise may have a positive impact on intra-tumoral immune cell processes, resulting in tumor suppression. This short narrative review describes the effect of physical exercise on tumor growth as detected via changes in tumor immunity. Research evidence shows that exercise may improve tumor-suppressive functions and may reduce tumor-progressive responses and mechanisms of immune cells, controlling tumor development. Specifically, it seems that exercise in rodents triggers shifts in tumor infiltration of macrophages, neutrophils, natural killer cells, cytotoxic and regulatory T lymphocytes, resulting in tumor suppression. These recent promising data suggest that physical exercise could be combined with anticancer immunotherapies, although exercise parameters like intensity, duration, and frequency need to be evaluated in more detail. More research is needed to investigate the effect of exercise in other immune cell subtypes and their possible connection with tumor growth, whilst information from human tumors is also required.

Download Full-text

The Effects of Acute Cardiovascular Exercise on Memory and Its Associations With Exercise-Induced Increases in Neurotrophic Factors

Frontiers in Aging Neuroscience ◽

10.3389/fnagi.2021.750401 ◽

2021 ◽

Vol 13 ◽

Author(s):

Laura A. Kuhne ◽

Anna-Maria Ksiezarczyk ◽

Klaus-Michael Braumann ◽

Rüdiger Reer ◽

Thomas Jacobs ◽

...

Keyword(s):

Physical Exercise ◽

Neurotrophic Factors ◽

Neurotrophic Factor ◽

Human Memory ◽

Exercise Session ◽

Cardiovascular Exercise ◽

Age Related ◽

Significant Difference ◽

Exercise Induced ◽

Induced Changes

Due to increasing life expectancy, low-cost interventions to counteract age-related memory impairment have gained popularity. Physical activity has been shown to positively affect memory and hippocampal plasticity in rodents and humans. These effects have been proposed to be mediated by the release of neurotrophic factors. However, studies examining the effects of a single cardiovascular exercise session on human memory have yielded conflicting results. Moreover, it remains unclear whether exercise-induced memory enhancements are related to changes in peripheral neurotrophic factor concentrations. The present study tested whether one bout of cardiovascular exercise during an early phase of memory consolidation, compared to one bout of stretching and toning, positively affected memory. Furthermore, it was analyzed whether exercise-induced changes in the brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) were related to memory enhancement after a single bout of physical exercise. Fifty healthy participants (20–40 years) were randomly assigned to either a cycling group (BIKE) or a stretching and toning group (STRETCH). Participants performed an implicit vocabulary learning task which was immediately followed by physical exercise. Memory for the learned vocabulary was tested 1–2 weeks later. To measure exercise-induced changes in serum neurotrophic factor levels, blood samples were collected at rest (baseline) and immediately after the exercise session. Results did not show a significant difference in memory between the BIKE group and the STRETCH group. However, in the BIKE group, a larger increase in BDNF and VEGF levels was observed than in the STRETCH group. Moreover, the increase in BDNF and memory performance tended to be positively related in the BIKE group. We speculate that the correlation between exercise-increased BDNF levels and memory in the cycling group may indicate an involvement of BDNF in mediating memory processes after acute cardiovascular exercise.

Download Full-text