Cycle ergometry

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Cardiac Strain during Upright Cycle Ergometry in Adolescent Males

Cardiac Strain during Upright Cycle Ergometry in Adolescent Males

submaximal exercise in young males. The aims of the study were to evaluate the changes that occur in longitudinal (L), radial (R) and endocardial circumferential (EC) strain during submaximal upright cycle ergometry and to examine the test-retest reproducibility of these measurements. Fourteen recreationally active, adolescent (age: 17.9 ± 0.7 years), males volunteered for the study. All subjects underwent an incremental (40W) submaximal cycle ergometer test. L, R, and EC strain values were obtained using speckle tracking, from two-dimensional B-mode images of the left ventricle (LV) during rest and the initial stages of submaximal exercise (40W and 80W). The average of 6 LV segments was used to determine both peak wall deformation (%) and the time to peak deformation (ms). There was a statistically (P<0.05) significant increase from rest to submaximal exercise for peak deformation for L, R and EC strain. There was a statistically significant (P<0.05) decrease from rest to submaximal exercise for time to peak for L and R and EC strain and between submaximal workloads for time to peak for L strain and EC strain. Coefficients of variation demonstrated reproducibility for upright strain and strain rate measurements similar to published supine measurements. This study has demonstrated that changes in left ventricular wall deformation (L, R and EC strain) that occur during the transition from rest to submaximal exercise can be reliably measured and confirm that a healthy left ventricle has a hyperdynamic response to exercise.

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Characteristics and determinants of endurance cycle ergometry and six-minute walk distance in patients with COPD

Characteristics and determinants of endurance cycle ergometry and six-minute walk distance in patients with COPD

There are methodological considerations to our study. It is a retrospective cohort study which means there may be unidentified confounders. We have no way of knowing why some of the records were incomplete. Surely some may be incomplete due to a failure of the patients to complete the initial pulmonary rehabilitation assessment, or refusal to perform a particular test. Some were also repeat evaluations. Nonetheless the large sample size helps to mitigate some of these potentially confounding factors. Secondly, this is a population of patients who have been referred for pulmonary rehabilitation which could result in a referral bias towards patients with a greater degree of limitation. Regardless, our findings sufficiently demonstrate that performing CET at 75% of peak work rate is a reasonable effort level for a population of COPD patients being referred for pulmonary rehabilita- tion. However, a fixed proportion of peak work rate exercise does not provide identical physiological stress amongst patients. Furthermore, this study increases our under- standing of gender differences in exercise testing and highlights the complex pathophysiology of exercise intoler- ance in COPD. There have been a number of gender differ- ences reported in COPD [27,30-36]. Most intriguingly, it has previously been shown that women have higher symp- tom scores on the St. George’s Respiratory Questionnaire (SGRQ) compared to men [27]. It may therefore be that compared to 6MWT, which simulates a more routine daily activity, cycle ergometry evokes more symptoms in women compared to men resulting in reduced CET-T end for

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Effects of creatine loading on electromyographic fatigue threshold during cycle ergometry in college-aged women

Effects of creatine loading on electromyographic fatigue threshold during cycle ergometry in college-aged women

Several studies have reported 4 to7 days of Cr loading is effective for enhancing anaerobic performance during repeated sprint cycling [24-27], resistance training [28,29], and anaerobic treadmill running [30]. In addi- tion, a few studies have demonstrated Cr loading to be an effective ergogenic aid for supramaximal workloads (>120% VO 2 max ) on a cycle ergometer [27,31-33]. The increase in exercise performance is believed to be attrib- uted to an increase in intramuscular stores of total PCr [15,34]. A few investigators [11,16,33] have suggested that increasing skeletal muscle PCr from Cr loading may improve supramaximal cycle ergometry performance by decreasing the reliance on anaerobic glycolysis for energy.

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Validation of activity questionnaires in patients with cystic fibrosis by accelerometry and cycle ergometry

Validation of activity questionnaires in patients with cystic fibrosis by accelerometry and cycle ergometry

as surrogate measure of PA [8]. Yet, accelerometry and cycle ergometry are expensive and time consuming and require specialized equipment. For the routine assess- ment of patients’ physical activity in a clinical setting, a quick and easily accessible tool at low costs is required. Therefore, questionnaires might be best suited to assess physical activity. Some of the existing instruments such as the Lipid Research Clinics (LRC), the Seven Day Phy- sical Activity Recall (7D-PAR), and the Habitual Activity Estimation Scale (HAES) questionnaire have been used and validated in healthy children and adults [9-12] and have also been employed in patients with CF [2,13,14]. However, in patients with CF a validation against objec- tive measures of physical activity has only been per- formed for the HAES in a relatively small group of young patients [13] and to our knowledge a validation of questionnaires with respect to aerobic fitness has not been performed at all.

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Functional electrical stimulation assisted cycle ergometry in the critically ill: protocol for a randomized controlled trial

Functional electrical stimulation assisted cycle ergometry in the critically ill: protocol for a randomized controlled trial

In the intervention arm, early goal-directed rehabilita- tion is protocolled according to the patients’ condition and degree of cooperation (Fig. 3), and there will be pre- defined safety criteria, which are in accordance with current recommendations for active rehabilitation of critically ill ventilated adults [13]. Whilst the safety cri- teria are binding for the study physiotherapist, the re- habilitation protocol is not and the delivery of physical exercise can be altered according to the actual patient’s condition. However, any alteration and the reason for it will be recorded. The intervention will start as soon as possible and always within 72 h of ICU admission, con- tinuing until ICU discharge. Supine cycling will be deliv- ered as per protocol on a supine cycle ergometer attached to a neuromuscular stimulator. Surface elec- trodes will be applied to the gluteal, hamstring and quadriceps muscles on both legs. The intensity of muscle stimulation will be delivered at a level able to cause visible contractions (confirmed by palpation if un- certain) in all muscle groups without causing undue pain or discomfort to the participant, according to a regime specified by Parry et al. [44]. Once the patient is more alert, and able to participate, they will be provided with standardized encouragement to engage in therapy. To increase the intervention workload, resistance will be in- creased incrementally and cycling cadence. If a partici- pant is readmitted to intensive care, the intervention will be re-initiated. The intervention continues until day 28 or ICU discharge, whichever occurs earlier.

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Development of 11- to 16-year-olds’ short-term power output determined using both treadmill running and cycle ergometry

Development of 11- to 16-year-olds’ short-term power output determined using both treadmill running and cycle ergometry

Potential limitations to this study lie in the tests themselves. The well-established WAnT uses apparatus readily avail- able in most paediatric exercise laboratories but to obtain true maximal power output on a cycle ergometer the braking force should be matched to muscle capability so that the test can be performed at optimal pedal cadence. In a longitudinal study, this would ideally require the optimal braking force to be determined specifically for each of PP and MP on each test occasion. However, as mentioned earlier, it appears that in the present age group the WAnT is generally resilient to moderate variations in body mass-related braking force around the conventional value of 0.74 N kg −1 and therefore

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Low doses of caffeine reduce heart rate during submaximal cycle ergometry

Low doses of caffeine reduce heart rate during submaximal cycle ergometry

Comparing the results of the current study to previous studies is somewhat difficult given the different doses of caffeine, types and intensities of exercise, and the varied use of either habituated or non-habituated subjects. How- ever, our finding of a lower heart rate with caffeine use during exercise is in agreement with three previous stud- ies. Sullivan et al. [11] studied five habituated and five non-habituated subjects who walked at 46% of VO2max and observed that the five non-habituated subjects showed a significantly lower heart rate after administra- tion of 3.3 mg/kg caffeine (133.9 vs 143.7 during pla- cebo) whereas the difference was not significant in the five habituated subjects (121.8 vs 124.4). Gaesser and Rich [10] gave 5 mg/kg caffeine to low to moderate caffeine users and found lower heart rates (6–10 bpm) compared to placebo at cycling exercise intensities between 30–70% of VO 2max . They found no difference in HR above 75% of VO 2max (HR > 160 bpm). More recently, Turley and Gerst [12] found lower heart rates in young boys and girls dur- ing cycle exercise at intensities of 41% and 64% of VO 2max

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VALIDATION OF THE PHYSICAL WORKING CAPACITY AT THE FATIGUE THRESHOLD TREADMILL TEST

VALIDATION OF THE PHYSICAL WORKING CAPACITY AT THE FATIGUE THRESHOLD TREADMILL TEST

treadmill test include both the athletic perfor- mance and rehabilitative applications as during cycle ergometry (Camic, et al., 2010b; deVries, et al., 1989; Emerson, et al., 2014; Jenkins, et al., 2014; Stout, et al., 2007a, 2007b, 2015; Zak, et al., 2015) that includes assessing physical fitness, evalu- ating the effectiveness of conditioning programs and nutritional supplements, prescribing exercise training intensities, and examining factors related to neuromuscular function in the elderly. Based on these practical applications and popularity of running, an examination into the validity of the PWC FT treadmill test is warranted. Therefore,

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Reliability and day-to-day variability of peak fat oxidation during treadmill ergometry

Reliability and day-to-day variability of peak fat oxidation during treadmill ergometry

LIPOXmax) has been reported for a variety of submaxi- mal incremental protocols [6, 7, 13–16]. However, all re- liability studies to date have used cycle ergometry as the exercising method of choice, which in turn may limit a valid transferability from any of the previously tested protocols and their respective reproducibility indicators into other types of exercise. Yet, despite running and walking being feasible and popular modalities among different target populations [17], there are to date no re- liability data on the estimations of Fat peak during tread-

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Using of spectral analysis of heart rate variability for increasing reliability of bicycle ergometry results

Using of spectral analysis of heart rate variability for increasing reliability of bicycle ergometry results

The aim was to study the suitability of the heart rate variability (HRV) spectral parameters for evaluations of bicycle ergometry results in coronary heart disease (CHD) patients. Methods. Our study included 243 male CHD patients aged 49±8 years. The coronary atherosclerosis was assessed by coronary angiography. The results of bicycle ergometry, Doppler echocardio- graphy and HRV spectral analysis were also analyzed. The duration of each stage of bicycle ergometry was 3 min, the initial load value was 25 W. Dynamic load continued until the patient had reached 75% of heart rate from his maximal age level. The maximal level of load achieved (i.e. load tolerance) was taken into conside- ration. We calculated sensitivity (Se), specificity (Sp), likelihood ratios of positive (LR+) and negative (LR–) bicycle ergometry results. Re- sults. All patients had similar clinical chara- cteristics. LR+ become maximal under the moderate load tolerance. LR- are maximal in the CHD patients with high load tolerance. Thus, the excessiveness of false-negative results of bi- cycle ergometry is in CHD patients with high load tolerance. Reliability of results of bicycle ergometry increased under using assessments of low-frequency (LF) range power of HRV spectrum. Conclusions. Thus,the using of LF range power of HRV spectrum increases relia- bility of bicycle ergometry (or other load tests) results in CHD patients.

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Measurement of changes in the oxygenation of quadriceps muscles during the voluntary and involuntary fatigue test in normal healthy sedentary subjects

Measurement of changes in the oxygenation of quadriceps muscles during the voluntary and involuntary fatigue test in normal healthy sedentary subjects

High-intensity cycle ergometry has been widely used to measure muscular performance throughout maximal exercise (Baker et al., 2001). Blood oxygen found reduced about 15- 30% during the high intensity exercise (Richardson et al., 1993; Rowell et al., 1989). However, one important finding of these studies is that the studies did find a relationship between fatigue development and oxygenation involving high intensity exercises. This could again be attributed to the fact that intra-muscular pressure increases at high intensity exercise, which diverts the metabolism to anaerobic pathways. This promotes the fatigue via other pathways other than oxygen reduction or aerobic pathways (Yamada et al., 2004). Baker et al. (2001) results show the substantial muscular upper body contribution during the high intensity exercise in cycle ergometry. Regardless of that Blangsted et al. (2005) and McNeil et al. (2006) results failed to achieve any significant correlation between the fatigue and oxygenation level. Only because of the intensity of work activity was low (10% MVC) as compared to our study. The failure to achieve significant correlation between the level of fatigue development and the level of oxygenation could be attributed to the fact that other mechanisms might be involved in the fatigue development apart from oxygenation. The results of cycle ergometry exercise was similar to Yamada et al. (2004) as current study utilized the same high intensity exercise which also supported by the Baker et al. (2001) where they found the substantial contribution of upper body muscle involved to increase the whole body blood flow. This has increased the metabolic demand of the muscle. Ultimately, the changes in the oxygen level in the muscle were found due to the high intensity exercise. On the other hand Inbar et al. (1996) and Van Mil et al. (1996) calculated the resistive force from body composition and utilized high intensity cycle ergometry exercise. This showed the realistic performance concerning the muscle fatigue and oxygen consumption. The current study was performed on the same mode as Inbar et al. (1996) and Van Mil et al. (1996) used in their study. In addition, the same results were obtained for high intensity cycle ergometry exercise and the development of fatigue with the reduction in the amount of oxygen.

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Cycle Mapping in the UK and the ‘London Cycle Map’

Cycle Mapping in the UK and the ‘London Cycle Map’

Maps are used to visualize geospatial data including distances, directions and elevations but in the case of many cycle maps they are also attempting to convey other information that is specific to cyclists’ needs but there is no consistency of the words used or their relationship to what is to be found on the ground (Sherwin and Bartle 2012). So for example, what is described as an off road route in one area might be shared path on the side of a road in one area or a piece of infrastructure unrelated to a road on another map. As participants in the focus groups conducted by Sherwin and Bartle (2012) had good local knowledge, they found discrepancies in the maps, questioning the labelling of some of the routes and whether it was possible to ‘trust’ the information shown on the maps. These difficulties of wording and representation were also partly a reflection of the lack of consistency of cycle infrastructure in the UK. One disagreement amongst participants concerned a narrow lane painted on the pavement of one side only of a busy road. Did this merit its

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Cycle-to-Cycle Control of the Thermoforming Reheat Process

Cycle-to-Cycle Control of the Thermoforming Reheat Process

Abstract—In this paper, we present a cycle-to-cycle repetitive control scheme for plastic sheet reheat in a thermoforming oven. Based on previous research on terminal iterative learning control, the notion of mode is introduced to the system to implement cyclic control of the sheet temperature. A hybrid dual-mode cascade-loop system is then designed where the inner loop monitors the real-time temperatures to ensure the quality of control in Mode 0 with the original PID control system of an AAA thermoforming machine, while the outer loop reads temperatures and commands at the end of each cycle to decide the necessity of switching to the mode of adjustment (MA, Mode 1), or vice versa. The simulation results present satisfactory performance with only a small sheet temperature error at the end of the cycle.

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The Intelligence Cycle

The Intelligence Cycle

According to the U.S. Marine Corps handbook: Counterintelligence (U.S. MARINE CORPS, 2007) , “The Intelligence Cycle is a procedure frame work for the development of mission-focused Intelligence support. It is not an end in it- self, nor should it be viewed as a rigid set of procedures that must be carried out in an identical manner on all occasions. The commander and the Intelligence of- ficer must consider each IR (Intelligence Requirement) individually and apply the Intelligence Cycle in a manner that develops the required Intelligence in the most effective way”.

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Design of LabVIEW Based SCADA System for Pneumatics Applications

Design of LabVIEW Based SCADA System for Pneumatics Applications

By selecting the appropriate menu the desired conditions are been selected using switch case function. The double acting cylinder can be operated for single cycle or multiple cycle by selecting the no of cycle the fig 8 shows the block diagram for single cycle sequence, buttons are provided for home position to come back to normal position.Similarly the hardware implementation are been down using myDAQ by configuring the digital inputs and outputs, limit switch are been used to determine the current position of the shaft which is been given as the input to the mydaq and the solenoid coil are been energized using relay to move the shaft forward and reverse. Depending upon the limit switch output the forward and reverse action are been performed.

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The considerable gain in power output and thermal efficiency noticed in Figures 2 and 3 makes the combined cycle plant suitable for base load power generation due to reduced cost of generation. To avoid having one steam turbine train for each gas turbine unit, it is more economical to have two gas turbines and HRSG to drive one steam turbine train as used in the design of the AGIP power installation in Kwale, Delta State. In such instance, the power output from the steam power output from the steam turbine generator terminal would be greatly increased.

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The Effects of Cash Conversion Cycle on Profitability: An Insight into the Agriculture and Food Industries in Thailand

The Effects of Cash Conversion Cycle on Profitability: An Insight into the Agriculture and Food Industries in Thailand

The study of cash conversion cycle is particularly significant for agriculture and food industries. Unlike other businesses, the agriculture and food industries have some unique risk factors to consider. Besides the general risks (access to growth capital, competition, etc.), the specific risks associated with the agricultural businesses (biological and weather related risks, commodity price volatility, infrastructure in rural areas and government polices) can greatly influence the profitability of this sector. In addition, the special nature of the supply chain and logistics design for food industries can amplify the challenges such companies face in working capital management. More importantly, speed plays a crucial role in this industry. Responsiveness is a key factor which influences speed; and the food industry in particular is an example of this “off-the-shelf” responsiveness characteristic (Kritchanchai, 2004). If a country cannot stock its produced food for a longer period of time, the possibilities of exporting such foods become limited to fresh foods only which are associated with higher costs (Afzal, Lawrey, Anaholy, & Gope, 2018). In other words, the agriculture and food industries are distinctive in the sense that the produce of these industries have a very limited shelf life.

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13C metabolic flux analysis on roles of malate transporter in lipid accumulation of Mucor circinelloides

13C metabolic flux analysis on roles of malate transporter in lipid accumulation of Mucor circinelloides

metabolic network topology and estimate intracellular fluxes of genetically engineered M. circinelloides strains for the purpose of better understanding the roles of malate transporters in citrate transport systems and lipid accumulation. Results: The metabolic flux distribution analysis suggested that tricarboxylic acid (TCA) cycle flux ratio of mt-overex- pression strains was decreased compared to that of the control strain, but in contrast, glyoxylic acid (GOX) cycle flux ratio was increased. Accordingly, the mt-knockout strain showed an opposite phenomenon with a higher TCA cycle flux ratio and a lower GOX cycle flux ratio than the control strain. GOX cycle might be more effective than TCA cycle in producing malate and oxaloacetate replenishment. Moreover, a relatively higher flux ratio of the pentose phos- phate (PP) pathway was obtained in mt-overexpression strains, but no significant difference in the malic enzyme flux between recombinant strains and the control strain. Our results confirmed that PP pathway might play an important role for supplying NADPH and malic enzyme is not a limiting factor for fatty acid synthesis in oleaginous fungus M. circinelloides strains.

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Effects of Upper Limb Exercises on Physical Capacity and Heart Function in Quadriplegics

Effects of Upper Limb Exercises on Physical Capacity and Heart Function in Quadriplegics

Dicarlo documented the effects of arm ergometry training on wheelchair propulsion in individuals with quadriplegia [8]. S.Nilsson and P.H Staff have shown a significant increase in the maximal oxygen uptake and maximal dynamic strength and endurance in 12 paraplegics who had undergone 7 weeks of intensive training [6]. Studies showing the physiological responses with an arm crank and wheelchair ergometry in SCI are well documented [9,10,11]. Studies have also shown the effects of strength training on wheelchair users [11,12].In this study there are not many studies that have compared the effects of arm ergometry training and strength training on resting heart rate and wheelchair propulsion in paraplegics.

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Sex-differences in response to arm and leg ergometry in juvenile judo athletes

Sex-differences in response to arm and leg ergometry in juvenile judo athletes

Also ventilatory indicators (absolute and relative VO 2 peak, and relative VEpeak) measured during arm ergometry and lactate concentration 3 min after breaking off cranking were significantly higher among men compared to women. These data suggest that, in comparison to coetaneous female judokas, male com- petitors at this age reach a higher maximal physi- cal power with the arms utilizing the aerobic as well as the anaerobic energy pathways. Indeed, it’s well known from the literature that men reach higher VO 2 peak values than women starting about from the 2 nd decade of age [19].

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