Resting and Post-Exercise Blood Pressure Response to Repeated Bouts of Aquatic Treadmill Exercise

Aerobic exercise is known to reduce resting blood pressure as well as induce and acute post-exercise hypotensive response. Purpose: Determine the effect of repeated bouts of aquatic treadmill exercise on consecutive days in physically untrained, pre-hypertensive men. Methods: Nine male subjects (SBP: 132 ± 8 mmHg; DBP: 79 ± 8 mmHG; 33 ± 8 years; 183 ± 7 cm; 103 ± 31 kg; 32 ± 10% Fat; 36 ± 7 ml·kg-1·min-1) participated in the study. All subjects completed an acute aquatic treadmill exercise session (60% VO2max; 300 kcal) on two consecutive days. Prior to each exercise session and following 10 minutes of seated rest, blood pressure and heart rate were automatically taken every 3 minutes for a total of 3 measurements. Following each exercise session, blood pressure and heart rate were measured automatically every 10-minutes from 20 to 60 minutes post while subjects were seated at rest. Pre-exercise and post-exercise measures were averaged. A dependent sample t-test was performed to compare the average values between the first (ATM1) and second (ATM2) exercise sessions. Results: Data are displayed in table below. Both pre-exercise and post-exercise systolic, diastolic, and mean arterial pressures were lower for ATM2. Conclusion: A single bout of ATM exercise resulted in reduced resting blood pressure 24-hours later. Furthermore, post-exercise blood pressure was lower following a second ATM exercise session. These data support both the efficacy of ATM exercise in regulating blood pressure and the cumulative benefit of repeated exercise bouts. Pre-Exercise Post-Exercise SBP DBP MAP HR SBP DBP MAP HR ATM1 Avg 126 78 96 72 124 77 93 83 SD 11 7 7 11 12 7 8 10 ATM2 Avg 121 74 92 70 120 75 91 80 SD 11 7 7 11 10 8 7 13 T-Test 0.035 0.005 0.003 0.113 0.047 0.028 0.034 0.058 All values represent mean ± SD. p-values compare ATM1 vs. ATM

Energy Expenditure Overestimation Bias in Elliptical Trainer Machine

Elliptical trainers are a common mode of aerobic exercise in recreationally active populations. Those with a weight loss goal might rely upon the energy expenditure (EE) estimation that many elliptical brands provide to keep track of calories (kcals) burned and make nutritional decisions. For this reason, it is important to evaluate the accuracy of the algorithms used by elliptical trainers to estimate EE. The purpose of this study was to compare EE estimates by a common brand of elliptical trainer to that measured using open circuit spirometry, at different combinations of resistance and pedal speed. Twenty subjects (10 male, 10 female; 34 ± 12 yr; 175.3 ± 10.7 cm; 77.1 ± 14.1 kg) consented to participate. Each completed three 15-min bouts of elliptical exercise on the same elliptical trainer, with at least 24 hr between exercise bouts. Pedal rates were held constant throughout each bout at 50, 60, or 70 RPM, and resistance was increased incrementally every 5 min from level 5 to 10 to 15. The different cadences were completed in a randomized order between participants. Expired gases were collected continuously throughout the 15 min. Heart rate, distance (mi), and EE from the elliptical readout were recorded every 1 min. RPE was collected twice per resistance level. A two-tailed paired samples t-test was used to compare elliptical EE to measured EE. A linear regression model was used to evaluate the ability of the elliptical EE to predict measured EE. Significance for all statistical measures was held at an alpha level of 0.05. The difference between EE estimates from the elliptical and measured VO2 was significant (p Measured EE = 0.95*(Elliptical EE) – 3.161 In conclusion, the elliptical trainer used for this study demonstrated a bias to overestimate EE. This should be taken into account by health/fitness professionals using these estimations to program for clients. There may be some variation in the EE correction regression depending on elliptical model, and proper machine calibration should be ensured

Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

Ultralight vector dark matter search using data from the KAGRA O3GK run

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

Alleles associated with physical activity levels are estimated to be older than anatomically modern humans.

The purpose of this study was to determine the estimated mutation age and conservation of single-nucleotide polymorphisms (SNPs) associated with physical activity (PA) in humans. All human SNPs found to be significantly associated with PA levels in the literature were cross-referenced with the National Heart, Lung, and Blood Institute's Grand Opportunity Exome Sequencing Project to find estimated African-American (AA) and European-American (EA) mutation age. As a secondary measure of mutation age, SNPs were searched for in Hawk's mutation age prediction database which utilizes linkage equilibrium. To determine conservation among hominids, all SNPs were searched in the University of California, Santa Cruz Genome Browser, which contains Neanderthal and chimpanzee reference genomes. Six of the 104 SNPs associated with PA regulation were exon-located missense variants found in IFNAR2, PPARGC1A, PML, CTBP2, IL5RA, and APOE genes. The remaining 98 SNPs were located in non-protein coding regions. Average AA and EA estimated mutation age of the exon-located SNPs were 478.4 ± 327.5 kya and 542.1 ± 369.4 kya, respectively. There were four selective sweeps (suggestive of strong positive selection) of SNPs in humans when compared to Neanderthal or chimpanzee genomes. Exon-located PA candidate SNPs are older than the hypothesized emergence of anatomically modern humans. However, 95% of PA associated SNPs are found in intron and intergenic location. Across all SNPs, there seems to be a high level of conservation of alleles between humans, Neanderthals, and chimpanzees. However, the presence of four selective sweeps suggests there were selection pressures or drift unique to Homo sapiens that influenced the development of mutations associated with PA regulation

High Fat High Sugar Diet Reduces Voluntary Wheel Running in Mice Independent of Sex Hormone Involvement

Introduction: Indirect results in humans suggest that chronic overfeeding decreases physical activity with few suggestions regarding what mechanism(s) may link overfeeding and decreased activity. The primary sex hormones are known regulators of activity and there are reports that chronic overfeeding alters sex hormone levels. Thepurpose of this study was to determine if chronic overfeeding altered wheel running through altered sex hormone levels.Materials and Methods: C57BL/6J mice were bred and the pups were weaned at 3-weeks of age and randomly assigned to either a control (CFD) or high fat/high sugar (HFHS) diet for 9–11 weeks depending on activity analysis. Nutritional intake, body composition, sex hormone levels, and 3-day and 2-week wheel-running activity were measured. Additionally, groups of HFHS animals were supplemented with testosterone (males) and 17β-estradiol (females) to determine if sex hormone augmentation altered diet-induced changes in activity.Results: 117 mice (56♂, 61♀) were analyzed. The HFHS mice consumed significantly more calories per day than CFD mice (male: p < 0.0001; female: p < 0.0001) and had significantly higher body fat (male: p < 0.0001; female: p < 0.0001). The HFHS diet did not reduce sex hormone levels, but did significantly reduce acute running-wheel distance in male (p = 0.05, 70 ± 28%) and female mice (p = 0.02, 57 ± 26%). In animals that received hormone supplementation, there was no significant effect on activity levels. Two-weeks of wheel access was not sufficient to alter HFHS-induced reductions in activity or increases in body fat.Conclusion: Chronic overfeeding reduces wheel running, but is independent of the primary sex hormones

Protein fractional synthesis rates within tissues of high- and low-active mice.

With the rise in physical inactivity and its related diseases, it is necessary to understand the mechanisms involved in physical activity regulation. Biological factors regulating physical activity are studied to establish a possible target for improving the physical activity level. However, little is known about the role metabolism plays in physical activity regulation. Therefore, we studied protein fractional synthesis rate (FSR) of multiple organ tissues of 12-week-old male mice that were previously established as inherently low-active (n = 15, C3H/HeJ strain) and high-active (n = 15, C57L/J strain). Total body water of each mouse was enriched to 5% deuterium oxide (D2O) via intraperitoneal injection and maintained with D2O enriched drinking water for about 24 h. Blood samples from the jugular vein and tissues (kidney, heart, lung, muscle, fat, jejunum, ileum, liver, brain, skin, and bone) were collected for enrichment analysis of alanine by LC-MS/MS. Protein FSR was calculated as -ln(1-enrichment). Data are mean±SE as fraction/day (unpaired t-test). Kidney protein FSR in the low-active mice was 7.82% higher than in high-active mice (low-active: 0.1863±0.0018, high-active: 0.1754±0.0028, p = 0.0030). No differences were found in any of the other measured organ tissues. However, all tissues resulted in a generally higher protein FSR in the low-activity mice compared to the high-activity mice (e.g. lung LA: 0.0711±0.0015, HA: 0.0643±0.0020, heart LA: 0.0649± 0.0013 HA: 0.0712±0.0073). Our observations suggest that high-active mice in most organ tissues are no more inherently equipped for metabolic adaptation than low-active mice, but there may be a connection between protein metabolism of kidney tissue and physical activity level. In addition, low-active mice have higher organ-specific baseline protein FSR possibly contributing to the inability to achieve higher physical activity levels