Preferred pedal rate: an index of cycling performance

The purpose of this study was to determine whether preferred pedal rate (PPR) could be used as an index of cycling performance. Thirteen competitive cyclists cycled at PPR during a graded test and a supra-threshold constant power test (CPT). The results showed that PPR values reported in CPT were correlated to both peak power determined from the graded test and exhaustion time assessed in CPT. Furthermore, multiple regression revealed that PPR values and P (peak) were two predictors of exhaustion time in CPT. Hence, this study suggests that coaches and sports scientists have to take into account PPR values complementary to P (peak) in order to evaluate the capacity of cycling performance.     

Physiological profile and predictors of cycling performance in ultra-endurance triathletes

BACKGROUND: To report physiological profiles, and investigate the relationship between selected physiological variables and cycling performance in ultra-endurance triathletes. METHODS: Participants: ten male (mean+/-SD, age; 32+/-5 years) ultra-endurance triathletes participated in the study. Physiological profiles were compared with 10 male age-matched control subjects. Measures: left ventricular structure (wall thickness [LVPWd], internal diameter [LVIDd], and mass [LVM]) and function (diastolic filling, fractional shortening, and stroke volume [SV]) were assessed using standard M-Mode, 2D, and Doppler echocardiography. Maximal and sub-maximal exercise gas exchange responses were measured on-line during a maximal ramping cycle-ergometer exercise test. RESULTS: Ultra-endurance triathletes demonstrated significantly larger LVPWd, LVIDd, LVM, SV, VO2max anaerobic threshold (AT), and power to body-mass ratio compared with controls. Cycling performance for both Ironman and half Ironman were significantly correlated with LVPWd, LVM, and SV. LVIDd was significantly correlated Ironman cycle time alone. Oxygen consumption (VO2) at AT, percentage of VO2max at AT, and peak power to bodymass ratio were significantly correlated to bike finish time in the half Ironman, but not Ironman. CONCLUSIONS: The correlation between cycling performance, LVM and SV suggests that the more conditioned athletes may be better able to maintain a high cardiac output during prolonged cycling. Sub-maximal gas exchange responses are predictors of cycling performance for the half-Ironman but not the Ironman. These results suggest that other factors including the longer duration swim prior to the cycling component, may impact upon cycle performance.     

Changes in cycling efficiency and performance after endurance exercise

PURPOSE: This study was designed to examine the effects of moderate-intensity endurance exercise on cycling performance, gross efficiency, and 30-s sprint power output. METHODS: Two separate experiments were conducted. After a controlled warm-up, subjects completed as much work as possible in a 5-min performance test (EXP1) or a maximal 30-s sprint test (EXP2). These initial exercise bouts were followed by approximately 60 min of cycling at approximately 60% VO2peak or an equivalent period of rest (control) before repeating the warm-up exercise and either the 5-min performance or 30-s sprint test. Expired gas for calculation of cycling gross efficiency was collected over the last minute of each warm-up period. RESULTS: Average 5-min performance power output was significantly reduced (12 W) after exercise in EXP1, and in EXP2 both peak and mean power output were significantly lower (26 and 35 W, respectively). Gross efficiency decreased significantly with exercise in both EXP1 and EXP2. Moreover, the change in gross efficiency was correlated with the change in 5-min performance (r = 0.91, P < 0.01), but not with the change in mean or peak 30-s sprint power output. CONCLUSIONS: After sustained moderate-intensity cycling significant reductions in 5-min performance, gross efficiency and sprint power output were observed in endurance trained cyclists. The reduction in 5-min performance was related to the exercise induced decrease in gross efficiency.     

Report generation using digital speech recognition in radiology

The aim of this study was to evaluate whether the use of a digital continuous speech recognition (CSR) in the field of radiology could lead to relevant time savings in generating a report. A CSR system (SP6000, Philips, Eindhoven, The Netherlands) for German was used to transform fluently spoken sentences into text. Two radiologists dictated a total of 450 reports on five radiological topics. Two typists edited those reports by means of conventional typing using a text editor (WinWord 6.0, Microsoft, Redmond, Wash.) installed on an IBM-compatible personal computer (PC). The same reports were generated using the CSR system and the performance of both systems was then evaluated by comparing the time needed to generate the reports and the error rates of both systems. In addition, the error rate of the CSR system and the time needed to create the reports was evaluated. The mean error rate for the CSR system was 5.5 %, and the mean error rate for conventional typing was 0.4 %. Reports edited with the CSR, on average, were generated 19 % faster compared with the conventional text-editing method. However, the amount of error rates and time savings were different and depended on topics, speakers, and typists. Using CSR the maximum time saving achieved was 28 % for the topic sonography. The CSR system was never slower, under any circumstances, than conventional typing on a PC. When compared with a conventional manual typing method, the CSR system proved to be useful in a clinical setting and saved time in generating radiological reports. The amount of time saved, however, greatly depended on the performance of the typist, the speaker, and on stored vocabulary provided by the CSR system. Received: 26 July 1999; Revised: 29 March 2000; Accepted: 31 March 2000     

Analysis of the results of a proficiency test in screening mammography at the CSPO of Florence: review of 705 tests

PURPOSE: The aim of this study was to evaluate the performance of a sample of Italian radiologists undergoing a proficiency test of screening mammography. MATERIALS AND METHODS: We retrospectively analysed the results of 705 tests (537 first tests, 168 repeat tests) taken during 1997-2005 by 537 Italian radiologists. The test, consisting of 17 screen-detected cancer cases and 133 negative controls, was validated by a panel of expert readers defining a minimum standard as to sensitivity for cancer and recall rate of negative controls. Success rates were assessed as a function of previous experience in mammography (years of experience, total mammograms read, mammograms read in the last year). RESULTS: A total of 176 radiologists successfully passed the test at their first attempt (32.7%). Success correlated with experience, measured in terms of years of experience (5-year cutoff: chi(2) for trend=4.17, p=0.04), total mammograms read (chi(2) for trend =11.8, p=0.002) or mammograms read in the last year (chi(2) for trend=6.27, p=0.04). Training improves performance at repeat testing: after a first negative attempt, a second attempt was successful in 50.6% of cases (74/146) and a third in 68.1% (15/22). CONCLUSIONS: A substantial proportion of Italian radiologists taking the test showed limited proficiency in screening mammography. This finding is consistent with several reports of poor performance of service screening compared with reference standards. As expected, test performance is associated with experience, suggesting that the current policy of employing non-dedicated, untrained, general radiologists in screening should be reconsidered. Test performance improves with training (courses, consultation of teaching atlases). Several screening programmes in Italy have been implemented without prior adequate radiologist training. Radiologist training needs to be considered a priority, at least in those screening programmes that are still to be implemented in one third of the country.     

Psychophysical power functions of exercise limiting symptoms in coronary heart disease

Thirty consecutive male patients with angiographically determined multivessel disease and ten healthy volunteers were subjected to a symptom limited exercise test with stepwise increments of 10 W every minute. Leg exertion, breathlessness, and chest pain were rated according to a category-ratio scale with 10 degrees and psychophysical power functions computed. Depending on whether chest pain was the limiting symptom, patients were subdivided into groups A (N = 20) and B (N = 10). Exercise capacity did not differ between groups A and B. Both groups terminated the exercise test at lower work loads and lower symptom intensities than the healthy volunteers. Psychophysical power functions were similar for leg exertion in the three groups while the growth of breathlessness was lower in group B. In group A the intensity of chest pain increased more rapidly than leg exertion or breathlessness. In conclusion, those patients with coronary heart disease interrupt the exercise test at lower ratings of leg exertion and breathlessness than healthy volunteers. The psychophysical power functions do not grow more rapidly for these sensory modalities in patients than in healthy volunteers.     

Effects of atropine and 2-PAM chloride on vision and performance in humans

These experiments assessed the time course and severity of effects of atropine and 2-PAM chloride on selected visual functions, physiological measures, and a tracking performance task. Atropine up to 4 mg X 70 kg-1 body weight and 2-PAM Cl in doses up to 1200 mg X 70 kg-1 body weight were administered intramuscularly in a double-blind Latin square design. A long lasting and dose-related increase in pupillary diameter and decrease in accommodative amplitude with accompanying loss of near visual acuity was found following atropine administration. These functions returned to baseline 2 d after injection. Distance acuity, contrast sensitivity, color vision, and intraocular pressure showed no changes after atropine. Tracking performance was significantly decreased by 4 mg of atropine. The changes in vision function cannot readily explain the tracking performance loss, since the tracking involved a distant visual target while the atropine produced degradation of near vision. Most of the physiological tests, tracking performance and all visual functions were unaffected by 2-PAM Cl.     

Effects of respiratory muscle endurance training on ventilatory and endurance performance of moderately trained cyclists

This study examined the effects of respiratory muscle endurance training (RMET) on ventilatory and endurance performance among moderately trained, male cyclists. Nine subjects initially completed two cycling VO2 max tests, two endurance cycling tests for time at 95% VO2 max, a 15-s MVV test, and an endurance breathing test for time at 100% MVV. Four subjects then underwent 3 weeks of strenuous RMET while five served as controls. Mean posttest 15-s MVV and endurance breathing time were significantly higher in the RMET group (243 +/- 14 l X min-1 and 804 +/- 94 s) than in the control group (205 +/- 6 l X min-1 and 48 +/- 8 s). No significant group differences in VO2 max or endurance cycling time at 95% VO2 max were observed following RMET. Results of this exploratory study indicated that RMET improved ventilatory power and endurance, but did not alter VO2 max or endurance cycling performance among moderately trained, male cyclists.     

Effect of new type of compression garments on sub-maximal and maximal cycling performance in the heat (32 °C)

This study investigated the effect of compression garments (X) on cycling performance in the heat (32 °C) and tested the hypothesis that X would not negatively affect cycling performance in the heat by comparing X and traditional cycling garments (C). Seven amateur cyclists and triathletes performed an incremental test followed by 20 min cycling performance test at a power that elicited the subject’s pre-determined 80 % of ventilator threshold and then a time to exhaustion (TTE) at VO₂max power (PPO) for both X condition and C condition (randomized). Oxygen uptake (VO₂) and heart rate were collected during steady state of sub-maximal intensity, TTE was taken at the end of maximal aerobic intensity and rating of perceived exertion, thermal and sweating sensation were provided every 5 min during the test. All parameters were compared between X and C; no significant differences (p < 0.05) were found, so the initial hypothesis was confirmed.     

Visual acuity of the U.S. Navy jet pilot and the use of the helmet sun visor

Visor wear habits, evaluative comments and vision test data were obtained from interviews of 126 Navy fighter pilots. The interviews revealed that many pilots use their helmet sun visor whenever they fly, some use it only during certain flight operations, and others never use it. Study 1 (conducted at 343 cd/m2) revealed a decrease in low contrast visual acuity attributable to helmet sun visor use in the presence of a glare source. These findings prompted a second study of the visual effects of visor transmittance. Low-contrast spot detection, acuity, and contrast sensitivity were measured at an operationally realistic daytime illumination level (6870 cd/m2) in subjects viewing through filters ranging from 6.3% to 50.1% transmission. (Standard visor transmission is 12 +/- 4%.) Results showed that filter density, and consequently the illuminance reaching the eyes, could be varied over a wide range without critically affecting these visual functions. Prevailing environmental illuminance should be considered when selecting sun visors or sunglasses. These results have implications for optimizing visual performance through visors.     

Are there hangover-effects on physical performance when melatonin is ingested by athletes before nocturnal sleep?

Athletes ingest melatonin in an attempt to improve sleep quality or alleviate symptoms of jet lag after transmeridian travel. It is not known whether there are residual effects of this hormone on physical performance in fit subjects. After a sample size estimation involving a meaningful effect on performance of 5%, five milligrams of melatonin or placebo were ingested by twelve physically-active subjects before sleep in a double-blind experiment. The following morning, subjective sleep quality (latency and maintenance) were measured together with intra-aural temperature, grip strength of the left and right hands, and time to complete a 4 km time trial on a cycle ergometer. The subjects also rated perceived exertion during the latter test. The null hypothesis of no effect of melatonin on either subjective sleep quality or physical performance measured the morning after administration could not be rejected on the basis of our observations (P > 0.30). The mean differences between treatments were less than 1% for the strength tests and time trial performance. The confidence intervals for these differences for left and right grip strength and the cycling test were - 2.1 to 2.8 kg, - 3.1 to 2.7 kg and -3.0 to 4.5 s, respectively. In conclusion, it is unlikely that 5 mg of melatonin would have any meaningful effects on physical performance in the morning after fit subjects ingest the hormone. There was also little evidence that it improves sleep quality in this population. Further research is needed concerning the effects of daytime and nighttime admistration of melatonin on performance, in both situations of normal and disturbed sleep.     

Comparison of the psychophysical properties of various intraoral film and digital systems by means of the perceptibility curve test

OBJECTIVES: To compare psychophysical properties of two intraoral films and three digital systems using the perceptibility curve (PC) test. MATERIALS AND METHODS: A test object was used to determine the exposures and exposure differences between the total thickness of the test object and details consisting of holes of increasing depth. The PCs for the two intraoral films, UltraSpeed and EktaSpeed Plus, were constructed employing exposure and exposure differences from dose response functions. Integrals of the PCs were calculated to obtain the psychophysical properties of the two films. Psychophysical properties of the two films were compared with those of the three digital systems published previously (CDR, Dixel and Digora). RESULTS: The PC for the EktaSpeed Plus showed a slightly higher peak than that for the UltraSpeed. Available exposure ranges were comparable. The PC for the EktaSpeed Plus was shifted to the left of the exposure axis indicating its higher sensitivity as compared with UltraSpeed. All three digital systems had narrower but higher peaks compared with the films. The integrals for the digital systems were considerably larger than those for the two film types. CONCLUSIONS: All the three digital systems have superior psychophysical properties compared with the two tested films.     

The reliability of balance tests performed on the kinesthetic ability trainer (KAT 2000)

The Kinesthetic Ability Trainer (KAT 2000) is a balance platform designed for training and functional testing of the neuromuscular control system. Forty healthy and sports-active persons were tested and 1 month later retested to investigate the reliability of the KAT 2000 testing “one-leg static balance” and “two-leg dynamic balance”. A significant improvement at retesting on the same day was seen in both tests; furthermore the dynamic test result improved significantly with retesting 1 month later. The data obtained made it possible to calculate the 95% confidence limits for an unchanged test result for a single person and a group of persons. The results show a clear learning effect when the persons are retested, especially in the dynamic test. The KAT 2000 can be used as a tool for testing groups of persons both in short- and long-term studies, but it cannot be used for testing single persons due to the great variance in the test results. Further investigations involving injured persons are needed to determine the range of improvement after intervention. Received: 19 April 1999/Accepted: 25 November 1999     

Computer-simulated lung nodules in digital chest radiographs for detection studies

Computer simulations of lung nodules overcome many shortcomings of creating radiographs using anthropomorphic nodule phantoms for lung nodule detection studies, but these algorithms can be cumbersome and involved. A simple, fast, and flexible computer program to simulate lung nodules in digital chest radiographs for detection studies is reported. To verify the realism of the simulated nodules, a psychophysical study and a statistical study were conducted. In the psychophysical study, six radiologists and four nonradiologists were asked to distinguish between 17 real lung nodules and 17 computer-simulated lung nodules shown in eight radiographs. The results show that the computer-simulated lung nodules are indistinguishable visually from real lung nodules. Using parameters from the Rose model of vision, results show that the simulated and real nodules are the same statistically. Thus, besides visual validity, statistical analysis in confirming the validity of the simulated lung nodules is included.     

Flat and uphill climb time trial performance prediction in elite amateur cyclists

The aim of this study was to determine physiological, anthropometric, biomechanical and hormonal variables related to road flat and uphill climb performance. Eighteen elite level amateur road cyclists (21.1 +/- 3.8 yrs), homogeneous with regard to time trial performance (coefficient of variation: 2.9-5.2 %), were measured for frontal area (FA), maximal strength, power, cross-sectional area of the quadriceps femoris muscle and basal serum concentrations of total testosterone (TT), free testosterone (FT) and cortisol (C). Maximal (W (max)) and submaximal workload were measured during a progressive discontinuous maximal cycling laboratory test, and two all-out time trial performance tests (duration range: 1049-1251 s) were also conducted outdoors on two separate days: a 14-km flat road (average gradient of 0.2 %) and a 6.7-km uphill climb (average gradient of 6 %). Significant negative correlations (p < 0.01-0.001) were observed between the individuals' 14-km flat time values and the individual values of W (max) (r = - 0.90) and FA (r = - 0.73). Regression analysis showed that the individual values of the 6.7-km uphill climb trial performance time correlated significantly (p < 0.05-0.001) with those of FT (r = - 0.75) and W (max) x kg (-1) (r = - 0.66). The present results suggest that flat time trial performance in highly elite amateur cyclists is mainly related to absolute maximal workload and anthropometric variables, whereas uphill climb time trial performance is associated with maximal workload normalized to body mass, as well as with an increased anabolic-androgenic activity.     

Correlations between physiological variables and performance in high level cross country off road cyclists

Objectives: To examine the relations between maximal and submaximal indices of aerobic fitness and off road cycling performance in a homogeneous group of high level mountain bikers. Methods: 12 internationally competitive mountain bikers completed the study. Maximum oxygen uptake (V^·O_2max), peak power output (PPO), power output (PO), and oxygen uptake (V^·O₂) at first (VT) and second (RCT) ventilatory thresholds were measured in the laboratory, and correlated with race time during a cross country circuit race. Results: The only physiological indices of aerobic fitness correlated with off road cycling performance were PO and V^·O₂ at RCT when normalised to body mass (r = –0.63 and r = –0.66, respectively; p<0.05). VT, V^·O_2max, and PPO were not correlated to performance in this homogeneous group of high level mountain bikers. Conclusions: The results of this study suggest that submaximal indices of aerobic fitness such as PO and V^·O₂ at RCT are more important determinants of off road cycling performance than maximal indices such as PPO and V^·O_2max. This study confirms the importance of body mass for mountain biking performance. As aerobic fitness explained only 40% of the variance, other physiological and technical factors should be investigated, as they may be important determinants of cross country performance among elite mountain bikers.     

Diurnal evolution of cycling biomechanical parameters during a 60‐s Wingate test

The purpose of this study was to assess the evolution of pedaling kinetics and kinematics during a short‐term fatigue cycling exercise at two times of day. Twenty active male subjects were asked to perform a 60‐s Wingate test against a constant braking resistance during two experimental sessions at 06:00 and 18:00 hours, i.e., very close to the hours of core temperature values, which are, respectively, the lowest and the highest. The results showed that the fatigue index was higher (P<0.05) at 18:00 hours (71.4%) than at 06:00 hours (69.2%) and power output was higher (P<0.05) in the evening than in the morning during the first 20 s of the test, after which no difference was observed. Taken together, these results showed a greater progression of fatigue in the evening than in the morning. The diurnal variations in performance and fatigue were associated (P<0.001) with diurnal changes in cycling kinematic parameters, characterized by a reduction in the range of motion of the ankle angle in the evening. These findings show that a time‐of‐day effect on movement patterns occurs during an anaerobic cycling exercise and that this phenomenon has a direct influence on performance and fatigue.     

Color vision tests for aviation: comparison of the anomaloscope and three lantern types

INTRODUCTION: A comparison of the results obtained with the Nagel anomaloscope and the Holmes-Wright Type A, Spectrolux, and Beyne aviation color vision lanterns was undertaken. The Joint Aviation Requirements (JAR) specify pass/fail limits for these four secondary color vision tests and the Ishihara screening test. The results for individuals on all five tests were studied. METHODS: The color vision of 55 color-vision deficient and 24 color-vision normal subjects, mostly applicant pilots, was assessed using a battery of tests, including the Ishihara plates, the Nagel anomaloscope, and three lanterns. The testing methods and characteristics of the lanterns and anomaloscope were compared. RESULTS: Of the color-deficient applicants, only deuteranomalous trichromats passed more than one of the four secondary JAR tests, but a pass on one test did not reliably predict a pass on another test. Three out of nine protanomalous trichromats passed the Nagel anomaloscope but failed all three lantern tests. Of the normal trichromats, 12 failed the anomaloscope and 12 failed the Beyne lantern. DISCUSSION: Variability in pass/fail results can be attributed to many factors apart from loss of chromatic sensitivity. Some normal trichromats can fail both the Ishihara screening and the secondary tests. The approved secondary test varies between countries and the outcome of regulatory assessment depends on the color vision test used. Since the flight safety consequences of the current situation cannot be ignored, the development of a less variable technique for color vision assessment that is accepted internationally, allied with a better understanding of color vision requirements, is needed.     

Color vision testing for the U.S. Naval Academy.

Normal color vision is a prerequisite for admission to the United States Naval Academy. The Farnsworth Lantern (FALANT) is the Navy's definitive test for color vision. A FALANT is not available at many locations where candidates are examined, so satisfactory performance on pseudoisochromatic plates has been considered an acceptable alternative. Until recently, the Farnsworth Dichotomous Test Panel D-15 had also been used as an alternative test, but is now considered unacceptable. In the summer of 1991, a large number of candidates reported for induction who were unable to pass the FALANT. Since their screening physical examinations had been reported to show normal color vision, a shadow of doubt was cast upon the ability of the alternative tests to predict performance on the FALANT. Four hundred subjects were then tested on several color vision tests to determine if these tests could predict FALANT success. The results of this study and recommendations are presented.     

Proficiency test in clinical mammography. Results of a consecutive series of 130 volunteer Italian radiologists

PURPOSE: We evaluated the results obtained by 130 Italian radiologists undergoing a proficiency test of clinical mammography. MATERIAL AND METHODS: Radiologists were invited to report a series of 100 mammograms (two views), including 32 cancers and 78 non-cancers, with limited information regarding age, subjective symptoms, and findings at palpation. Sensitivity and specificity were then calculated. The test was validated by a panel of experts, and standards for test sufficiency were established on that basis (sensitivity > 80%, specificity > 85%). The tested radiologists differed by mammographic practice (average = 5.7 years, range 0.5-18), total number of mammograms read (average = 8,784, range 300-50,000) and per year (average = 1,535 range 300-5,000). RESULTS: Sensitivity (standard > 80%, average 81.1%, range 39-100%) and specificity (standard > 85%, average 84.0%, range 38-98%) standards were reached by 79 (60.8%) and 81 (62.3%) radiologists, respectively. Overall, only 37 (28.5%) radiologists passed the test (reached both standards). Mammographic practice (years of experience) (chi 2 for trend 5.26, p = 0.02), total mammograms read (chi 2 5.86, p = 0.05), and mammograms read per year (chi 2 8.07, p = 0.01) significantly correlated with a sufficient test. DISCUSSION: The evaluated sample is rather large but not necessarily representative of Italian radiologists. Had the sample been selected, there is no way to know if the results would have been biased towards a better or worse figure with respect to the national average. A significant correlation was found with reading experience (the best results were obtained by operators with > 10,000 films read and with > 2,000 films read/year), as which is important because most Italian radiologists reporting mammography usually read a limited number of cases. CONCLUSIONS: These results on such a wide sample of radiologists, possibly representative of the national average, are disappointing, and suggest that the average quality of mammography reporting in Italy may not be up to standards. Thus, we suggest that quality control program for clinical mammography not only test the equipment but include training and accreditation of radiologists.