Perceived Exertion as a Part of a Feedback System and its Interaction with Tactical Behaviour in Endurance Sports

1986 ◽  
pp. 317-326 ◽  
Author(s):  
H. V. Ulmer
Keyword(s):  
Perceived Exertion ◽  
Feedback System ◽  
Endurance Sports

scholarly journals The effects of dietary nitrate supplementation on endurance exercise performance and cardiorespiratory measures in healthy adults: a systematic review and meta-analysis

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Chloe Gao ◽  
Saurabh Gupta ◽  
Taranah Adli ◽  
Winston Hou ◽  
Reid Coolsaet ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Time Trial ◽  
Cochrane Collaboration ◽  
Performance Measure ◽  
Time To Exhaustion ◽  
Cochrane Central Register ◽  
Endurance Sports ◽  
Dietary Nitrate ◽  
Significant Difference ◽  
Nitrate Supplementation

Abstract Background Nitrate supplementation is thought to improve performance in endurance sports. Objective To meta-analyze studies evaluating the effect of nitrate supplementation on endurance sports performance among adults. Data sources We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Web of Science and CINAHL without language restrictions. Methods We included studies that: 1) compared nitrate supplementation with placebo; 2) enrolled adults engaging in an endurance-based activity; and 3) reported a performance measure or surrogate physiologic outcome. We evaluated risk of bias using the Cochrane Collaboration tool and pooled data with a random-effects model. We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to evaluate confidence in estimates. Results We included 73 studies (n = 1061). Nitrate supplementation improved power output (MD 4.6 watts, P < 0.0001), time to exhaustion (MD 25.3 s, P < 0.00001), and distance travelled (MD 163.7 m, P = 0.03). We found no significant difference on perceived exertion, time trial performance and work done. Nitrate supplementation decreased VO2 (MD − 0.04 L/min, P < 0.00001) but had no significant effect on VO2max or blood lactate levels. Conclusion The available evidence suggests that dietary nitrate supplementation benefits performance-related outcomes for endurance sports.

scholarly journals Quantification of Training and Competition Loads in Endurance Sports: Methods and Applications

2017 ◽  
Vol 12 (s2) ◽  
pp. S2-9-S2-17 ◽  
Author(s):  
Iñigo Mujika
Keyword(s):  
Perceived Exertion ◽  
Training Programs ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Rating Of Perceived Exertion ◽  
Stress Recovery ◽  
Endurance Sports ◽  
Biological Stress ◽  
Technological Advances ◽  
And Performance

Training quantification is basic to evaluate an endurance athlete’s responses to training loads, ensure adequate stress/recovery balance, and determine the relationship between training and performance. Quantifying both external and internal workload is important, because external workload does not measure the biological stress imposed by the exercise sessions. Generally used quantification methods include retrospective questionnaires, diaries, direct observation, and physiological monitoring, often based on the measurement of oxygen uptake, heart rate, and blood lactate concentration. Other methods in use in endurance sports include speed measurement and the measurement of power output, made possible by recent technological advances such as power meters in cycling and triathlon. Among subjective methods of quantification, rating of perceived exertion stands out because of its wide use. Concurrent assessments of the various quantification methods allow researchers and practitioners to evaluate stress/recovery balance, adjust individual training programs, and determine the relationships between external load, internal load, and athletes’ performance. This brief review summarizes the most relevant external- and internal-workload-quantification methods in endurance sports and provides practical examples of their implementation to adjust the training programs of elite athletes in accordance with their individualized stress/recovery balance.

Experiments with a scanning tunneling microscope (STM) mounted in a scanning electron microscope (SEM)

1986 ◽  
Vol 44 ◽  
pp. 636-639
Author(s):  
Oliver C. Wells ◽  
Mark E. Welland
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Mechanical Stability ◽  
Tunneling Current ◽  
Feedback System ◽  
Scanning Tunneling ◽  
Surface Profiling ◽  
Close Proximity ◽  
Metal Tip ◽  
Scanning Electron

Scanning tunneling microscopes (STM) exist in two versions. In both of these, a pointed metal tip is scanned in close proximity to the specimen surface by means of three piezos. The distance of the tip from the sample is controlled by a feedback system to give a constant tunneling current between the tip and the sample. In the low-end STM, the system has a mechanical stability and a noise level to give a vertical resolution of between 0.1 nm and 1.0 nm. The atomic resolution STM can show individual atoms on the surface of the specimen.A low-end STM has been put into the specimen chamber of a scanning electron microscope (SEM). The first objective was to investigate technological problems such as surface profiling. The second objective was for exploratory studies. This second objective has already been achieved by showing that the STM can be used to study trapping sites in SiO2.

Sign in / Sign up

Export Citation Format

Share Document