scholarly journals Exercise in Water Provides Better Cardiac Energy Efficiency Than on Land

2021 ◽  
Vol 8 ◽  
Author(s):  
Marina Fukuie ◽  
Daisuke Hoshi ◽  
Tatsuya Hashitomi ◽  
Koichi Watanabe ◽  
Takashi Tarumi ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Oxygen Supply ◽  
Pressure Rise ◽  
Aortic Pressure ◽  
Analysis Of Covariance ◽  
Moderate Intensity ◽  
Cycling Exercise ◽  
Intensity Effect ◽  
Water Based ◽  
Myocardial Oxygen Supply

Although water-based exercise is one of the most recommended forms of physical activity, little information is available regarding its influence on cardiac workload and myocardial oxygen supply-to-demand. To address this question, we compared subendocardial viability ratio (SEVR, the ratio of myocardial oxygen supply-to-demand), cardiac inotropy (via the maximum rate of aortic pressure rise [dP/dTmax]), and stroke volume (SV, via a Modelflow method) responses between water- and land-based exercise. Eleven healthy men aged 24 ± 1 years underwent mild- to moderate-intensity cycling exercise in water (WC) and on land (LC) consecutively on separate days. In WC, cardiorespiratory variables were monitored during leg cycling exercise (30, 45, and 60 rpm of cadence for 5 min each) using an immersible stationary bicycle. In LC, each participant performed a cycling exercise at the oxygen consumption (VO2) matched to the WC. SEVR and dP/dTmax were obtained by using the pulse wave analysis from peripheral arterial pressure waveforms. With increasing exercise intensity, SEVR exhibited similar progressive reductions in WC (from 211 ± 44 to 75 ± 11%) and LC (from 215 ± 34 to 78 ± 9%) (intensity effect: P < 0.001) without their conditional differences. WC showed higher SV at rest and a smaller increase in SV than LC (environment-intensity interaction: P = 0.009). The main effect of environment on SV was significant (P = 0.002), but that of dP/dTmax was not (P = 0.155). SV was correlated with dP/dTmax (r = 0.717, P < 0.001). When analysis of covariance (ANCOVA) was performed with dP/dTmax as a covariate, the environment effect on SV was still significant (P < 0.001), although environment-intensity interaction was abolished (P = 0.543). These results suggest that water-based exercise does not elicit unfavorable myocardial oxygen supply-to-demand balance at mild-to-moderate intensity compared with land-based exercise. Rather, water-based exercise may achieve higher SV and better myocardial energy efficiency than land-based exercise, even at the same inotropic force.

scholarly journals ‘Tracking Together’—Simultaneous Use of Human and Dog Activity Trackers: Protocol for a Factorial, Randomized Controlled Pilot Trial

2021 ◽  
Vol 18 (4) ◽  
pp. 1561
Author(s):  
Wasantha Jayawardene ◽  
Lesa Huber ◽  
Jimmy McDonnell ◽  
Laurel Curran ◽  
Sarah Larson ◽  
...  
Keyword(s):  
Physical Activity ◽  
Controlled Trial ◽  
Pilot Trial ◽  
Activity Level ◽  
Analysis Of Covariance ◽  
Moderate Intensity ◽  
Randomized Controlled ◽  
Activity Trackers ◽  
Dog Owners ◽  
Simultaneous Use

Dog-walkers are more likely to achieve moderate-intensity physical activity. Linking the use of activity trackers with dog-walking may be beneficial both in terms of improving the targeted behavior and increasing the likelihood of sustained use. This manuscript aims to describe the protocol of a pilot study which intends to examine the effects of simultaneous use of activity trackers by humans and their dogs on the physical activity level of humans and dogs. This study uses nonprobability sampling of dog owners of age 25–65 (N = 80) and involves four parallel groups in an observational randomized controlled trial with a 2 × 2 factorial design, based on use of dog or human activity trackers for eight weeks. Each group consists of dog-human duos, in which both, either or none are wearing an activity tracker for eight weeks. At baseline and end, all human subjects wear ActiGraph accelerometers that quantify physical activity for one week. Commercial activity trackers are used for tracking human and dog activity remotely. Additional measures for humans are body composition and self-reported physical activity. Dog owners also report dog’s weight and physical activity using a questionnaire. A factorial analysis of covariance (ANCOVA) is used to compare physical activity across the four groups from baseline to week-10.

910 ESTIMATED MYOCARDIAL OXYGEN SUPPLY TO DEMAND RATIO DURING BILATERAL ARM RESISTANCE EXERCISES AND ARM ERGOMETRY

1994 ◽  
Vol 26 (Supplement) ◽  
pp. S162
Author(s):  
J. L. O??Brien ◽  
A. L. Hicks ◽  
N. McCartney ◽  
D. McConachie ◽  
J. D. MacDougall ◽  
...  
Keyword(s):  
Oxygen Supply ◽  
Arm Ergometry ◽  
Resistance Exercises ◽  
Myocardial Oxygen Supply

scholarly journals Key Factors Influencing the Achievement of Climate Neutrality Targets in the Manufacturing Industry: LMDI Decomposition Analysis

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8006
Author(s):  
Kristiāna Dolge ◽  
Dagnija Blumberga
Keyword(s):  
Energy Efficiency ◽  
Co2 Emissions ◽  
Manufacturing Industry ◽  
Decomposition Analysis ◽  
Clean Energy ◽  
Industrial Activity ◽  
Intensity Effect ◽  
Wood Processing ◽  
Activity Effect ◽  
The Impact

The manufacturing industry is often caught in the sustainability dilemma between economic growth targets and climate action plans. In this study, a Log-Mean Divisia Index (LMDI) decomposition analysis is applied to investigate how the amount of industrial energy-related CO2 emissions in Latvia has changed in the period from 1995 to 2019. The change in aggregate energy-related CO2 emissions in manufacturing industries is measured by five different factors: the industrial activity effect, structural change effect, energy intensity effect, fuel mix effect, and emission intensity effect. The decomposition analysis results showed that while there has been significant improvement in energy efficiency and decarbonization measures in industry, in recent years, the impact of the improvements has been largely offset by increased industrial activity in energy-intensive sectors such as wood processing and non-metallic mineral production. The results show that energy efficiency measures in industry contribute most to reducing carbon emissions. In the future, additional policies are needed to accelerate the deployment of clean energy and energy efficiency technologies.

Noninvasive Assessment of Myocardial Oxygen Supply/Demand

1991 ◽  
Vol 5 (2) ◽  
pp. 110-114
Author(s):  
Giuseppe Ferro ◽  
Letìzia Spinelli ◽  
Carlo Duilio ◽  
Marco Spadafora ◽  
Franco Guarnaccia ◽  
...  
Keyword(s):  
Oxygen Supply ◽  
Noninvasive Assessment ◽  
Myocardial Oxygen Supply

Right ventricular oxygen supply/demand balance in exercising dogs

2001 ◽  
Vol 281 (2) ◽  
pp. H823-H830 ◽  
Author(s):  
Bradley J. Hart ◽  
Xiaoming Bian ◽  
Patricia A. Gwirtz ◽  
Srinath Setty ◽  
H. Fred Downey
Keyword(s):  
Right Ventricular ◽  
Oxygen Supply ◽  
Venous Blood ◽  
Oxygen Demand ◽  
Aortic Pressure ◽  
Left Ventricular ◽  
Strenuous Exercise ◽  
Conscious Animal ◽  
Flow Reserve ◽  
Exercise Induced

This is the first investigation of right ventricular (RV) myocardial oxygen supply/demand balance in a conscious animal. A novel technique developed in our laboratory was used to collect right coronary (RC) venous blood samples from seven instrumented, conscious dogs at rest and during graded treadmill exercise. Contributions of the RV oxygen extraction reserve and the RC flow reserve to exercise-induced increases in RV oxygen demand were measured. Strenuous exercise caused a 269% increase in RV oxygen consumption. Expanded arteriovenous oxygen content difference (A-VΔO2) provided 58% of this increase in oxygen demand, and increased RC blood flow (RCBF) provided 42%. At less strenuous exercise, expanded A-VΔO2 provided 60–80% of the required oxygen, and increases in RCBF were small and driven by increased aortic pressure. RC resistance fell only at strenuous exercise after the extraction reserve had been mobilized. Thus RC resistance was unaffected by large decreases in RC venous Po 2 until an apparent threshold at 20 mmHg was reached. Comparisons of RV findings with published left ventricular data from exercising dogs demonstrated that increased O2 demand of the left ventricle is met primarily by increasing coronary flow, whereas increased O2extraction makes a greater contribution to RV O2 supply.

Sign in / Sign up

Export Citation Format

Share Document