scholarly journals Nose-down saddle tilt improves gross efficiency during seated uphill cycling

2021 ◽  
Author(s):  
Ross D. Wilkinson ◽  
Rodger Kram
Keyword(s):  
Carbon Dioxide Production ◽  
Gas Analysis ◽  
Saddle Nose ◽  
Efficiency Improvement ◽  
Improve Performance ◽  
Gross Efficiency ◽  
Cycling Efficiency ◽  
Expired Gas Analysis ◽  
Expired Gas ◽  
Analysis System

Riding uphill presents a challenge to competitive and recreational cyclists. Based on only limited evidence, some scientists have reported that tilting the saddle nose down improves uphill-cycling efficiency by as much as 6%. Purpose: Here, we investigated if simply tilting the saddle nose down increases efficiency during uphill cycling, which would presumably improve performance. Methods: Nineteen healthy, recreational cyclists performed multiple 5-min trials of seated cycling at ~3 W kg–1 on a large, custom-built treadmill inclined to 8° under two saddle-tilt angle conditions: parallel to the riding surface and 8° nose down. We measured subjects’ rates of oxygen consumption and carbon dioxide production using an expired-gas analysis system and then calculated their average metabolic power during the last two min of each 5-min trial. Results: We found that, compared to the parallel-saddle condition, tilting the saddle nose down by 8° improved gross efficiency from 0.205 to 0.208 –– an average increase of 1.4 ± 0.2%, t = 5.9, p < .001, CI95% [0.9, 1.9], ES = 1.3. Conclusion: Our findings are relevant to competitive and recreational cyclists and present an opportunity for innovating new devices and saddle designs that enhance uphill cycling efficiency. The effect of saddle tilt on other slopes and the mechanism behind the efficiency improvement remain to be investigated.

Exercise testing and expired gas analysis

2009 ◽  
pp. 51-59
Author(s):  
Jean-Marc Foult ◽  
Bernard Attal ◽  
Alain Ducardonnet ◽  
Jean-Marc Foult ◽  
Olivier Hoffman ◽  
...  
Keyword(s):  
Exercise Testing ◽  
Gas Analysis ◽  
Expired Gas Analysis ◽  
Expired Gas

scholarly journals 981-49 Post Exercise Expired Gas Analysis in Patients with Dilated Cardiomyopathy

1995 ◽  
Vol 25 (2) ◽  
pp. 265A
Author(s):  
Pascal de Groote ◽  
Alain Milliare ◽  
Eric Decoulx ◽  
Gérard Ducloux
Keyword(s):  
Dilated Cardiomyopathy ◽  
Gas Analysis ◽  
Post Exercise ◽  
Expired Gas Analysis ◽  
Expired Gas

Expired Gas Analysis During Exercise Testing Pre-pneumonectomy

Surgery Today ◽  
2005 ◽  
Vol 35 (12) ◽  
pp. 1021-1025 ◽  
Author(s):  
Yoshinori Nagamatsu ◽  
Yasuhiro Terazaki ◽  
Fumihiko Muta ◽  
Hideaki Yamana ◽  
Kazuo Shirouzu ◽  
...  
Keyword(s):  
Exercise Testing ◽  
Gas Analysis ◽  
Expired Gas Analysis ◽  
Expired Gas

Cardiopulmonary Exercise Testing

2018 ◽  
pp. 413-436
Author(s):  
Andrew Kao
Keyword(s):  
Exercise Testing ◽  
Exercise Physiology ◽  
Cardiopulmonary Exercise Testing ◽  
Gas Analysis ◽  
Peak Oxygen Consumption ◽  
Normative Values ◽  
Cardiopulmonary Exercise ◽  
Expired Gas Analysis ◽  
Expired Gas

The chapter Cardiopulmonary Exercise Testing focuses on the opportunities provided by cardiopulmonary exercise (CPX) testing. The coordination of 5 organ systems is described in normal exercise physiology to understand abnormal exercise findings. From a few measured expired gas analysis parameters, most of the important exercise variables can be derived, including the peak oxygen consumption (peak VO2). The contribution of both the aerobic and anaerobic phases of exercise to total exercise capacity are described, including the methods for determination of the anaerobic threshold. The calculation of the normative values of peak VO2 are included, and a suggested template of a CPX report is included. The use of CPX testing in the determination of prognosis in heart failure patients is included.

Application of Wavelet Threshold Denoising Technique in Expired Gas Analysis Based on Laser Spectroscopy

2017 ◽  
Vol 44 (11) ◽  
pp. 1111003
Author(s):  
周 超 Zhou Chao ◽  
刘宁武 Liu Ningwu ◽  
何天博 He Tianbo ◽  
周 胜 Zhou Sheng ◽  
张 磊 Zhang Lei ◽  
...  
Keyword(s):  
Laser Spectroscopy ◽  
Gas Analysis ◽  
Expired Gas Analysis ◽  
Expired Gas

scholarly journals Preoperative Spirometry Versus Expired Gas Analysis During Exercise Testing as Predictors of Cardiopulmonary Complications After Lung Resection

Surgery Today ◽  
2004 ◽  
Vol 34 (2) ◽  
pp. 107-110 ◽  
Author(s):  
Yoshinori Nagamatsu ◽  
Ichirou Shima ◽  
Akihiro Hayashi ◽  
Hideaki Yamana ◽  
Kazuo Shirouzu ◽  
...  
Keyword(s):  
Exercise Testing ◽  
Lung Resection ◽  
Gas Analysis ◽  
Cardiopulmonary Complications ◽  
Expired Gas Analysis ◽  
Expired Gas

scholarly journals Older adults learn less, but still reduce metabolic cost, during motor adaptation

2014 ◽  
Vol 111 (1) ◽  
pp. 135-144 ◽  
Author(s):  
Helen J. Huang ◽  
Alaa A. Ahmed
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Muscle Activity ◽  
Motor Adaptation ◽  
Metabolic Cost ◽  
Gas Analysis ◽  
The Novel ◽  
Age Related ◽  
Expired Gas Analysis ◽  
Expired Gas

The ability to learn new movements and dynamics is important for maintaining independence with advancing age. Age-related sensorimotor changes and increased muscle coactivation likely alter the trial-and-error-based process of adapting to new movement demands (motor adaptation). Here, we asked, to what extent is motor adaptation to novel dynamics maintained in older adults (≥65 yr)? We hypothesized that older adults would adapt to the novel dynamics less well than young adults. Because older adults often use muscle coactivation, we expected older adults to use greater muscle coactivation during motor adaptation than young adults. Nevertheless, we predicted that older adults would reduce muscle activity and metabolic cost with motor adaptation, similar to young adults. Seated older ( n = 11, 73.8 ± 5.6 yr) and young ( n = 15, 23.8 ± 4.7 yr) adults made targeted reaching movements while grasping a robotic arm. We measured their metabolic rate continuously via expired gas analysis. A force field was used to add novel dynamics. Older adults had greater movement deviations and compensated for just 65% of the novel dynamics compared with 84% in young adults. As expected, older adults used greater muscle coactivation than young adults. Last, older adults reduced muscle activity with motor adaptation and had consistent reductions in metabolic cost later during motor adaptation, similar to young adults. These results suggest that despite increased muscle coactivation, older adults can adapt to the novel dynamics, albeit less accurately. These results also suggest that reductions in metabolic cost may be a fundamental feature of motor adaptation.

scholarly journals Association between Oxygen Delivery and Consumption in Patients Undergoing Cardiac Surgery. is There Supply Dependence?

1996 ◽  
Vol 24 (6) ◽  
pp. 651-657 ◽  
Author(s):  
P. S. Myles ◽  
R. Mcrae ◽  
I. Ryder ◽  
J. O. Hunt ◽  
M. R. Buckland
Keyword(s):  
Cardiac Surgery ◽  
Oxygen Delivery ◽  
Oxygen Supply ◽  
Gas Analysis ◽  
Surgical Patients ◽  
Poor Agreement ◽  
Oxygen Extraction Ratio ◽  
Expired Gas Analysis ◽  
Expired Gas ◽  
The Relationship

We studied the relationship between oxygen delivery (DO2) and consumption (VO2) in twenty patients undergoing cardiac surgery, in order to determine if VO2was dependent on DO2(pathological oxygen supply dependence). We measured VO2from expired gas analysis (VO2G) and compared this to that calculated using the reverse Fick method (VO2F). Both VO2Gand VO2Fincreased after cardiopulmonary bypass (P<0.001), without change in DO2(i.e. oxygen extraction ratio increased). There was a significant relationship between changes in DO2and VO2F, both before bypass (r=0.74, P < 0.001) and after bypass (r=0.69, P < 0.001), while changes in DO2and VO2Ghad no such relationship (pre-bypass: r=0.38, P=0.094; post-bypass: r=0.10, P=0.68). There was poor agreement between VO2Fand VO2Gperioperatively. We could not demonstrate supply dependence in elective cardiac surgical patients.

scholarly journals Quadrupedal Locomotion–Respiration Entrainment and Metabolic Economy in Cross-Country Skiers

2016 ◽  
Vol 32 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Kevin Boldt ◽  
Anthony Killick ◽  
Walter Herzog
Keyword(s):  
Breathing Pattern ◽  
Metabolic Cost ◽  
Gas Analysis ◽  
Running Economy ◽  
Human Gait ◽  
Expired Gas Analysis ◽  
Gait Mechanics ◽  
Expired Gas ◽  
Cross Country Skiing ◽  
Cross Country

A 1:1 locomotion–respiration entrainment is observed in galloping quadrupeds, and is thought to improve running economy. However, this has not been tested directly in animals, as animals cannot voluntarily disrupt this entrainment. The purpose of this study was to evaluate metabolic economy in a human gait involving all four limbs, cross-country skiing, in natural entrainment and forced nonentrainment. Nine elite cross-country skiers roller skied at constant speed using the 2-skate technique. In the first and last conditions, athletes used the natural entrained breathing pattern: inhaling with arm recovery and exhaling with arm propulsion, and in the second condition, the athletes disentrained their breathing pattern. The rate of oxygen uptake (VO2) and metabolic rate (MR) were measured via expired gas analysis. Propulsive forces were measured with instrumented skis and poles. VO2 and MR increased by 4% and 5% respectively when skiers used the disentrained compared with the entrained breathing pattern. There were no differences in ski or pole forces or in timing of the gait cycle between conditions. We conclude that breathing entrainment reduces metabolic cost of cross-country skiing by approximately 4%. Further, this reduction is likely a result of the entrainment rather than alterations in gait mechanics.

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