Search

Purpose: To compare performance data of adolescents collected with five different bicycle spiroergometry protocols and to assess the necessity for establishing standard values for each protocol., Methods: One-hundred-twenty adolescents completed two bicycle spiroergometries within 14 days. One of the two tests was performed based on our institutional weight-adapted protocol (P0). The other test was performed based on one out of four exercise protocols widely used for children and adolescents (P1, 2, 3 or 4) with 30 persons each. The two tests were performed in a random order. Routine parameters of cardiopulmonary exercise tests (CPET) such as VO 2 peak, maximum power, O 2 pulse, OUES, VE/VCO 2 slope as well as ventilatory and lactate thresholds were investigated. Agreement between protocols was evaluated by Bland-Altman analysis, coefficients of variation (CV) and intra-class correlation coefficients (ICC)., Results: None of the CPET parameters were significantly different between P0 and P1, 2, 3 or 4. For most of the parameters, low biases between P0 and P1-P4 were found and 95% confidence intervalls were narrow. CV and ICC values largely corresponded to well-defined analytical goals (CV < 10% and ICC > 0.9). Only maximal power (Pmax) showed differences in size and drift of the bias depending on the length of the step duration of the protocols., Conclusion: Comparability between examination protocols has been shown for CPET parameters independent on step duration. Protocol-dependent standard values do not appear to be necessary. Only Pmax is dependent on the step duration, but in most cases, this has no significant influence on the fitness assessment.

Purpose: To investigate whether a metabolic cart using a flowmeter in the upper range of accepted resistance to airflow (<1.5 cmH 2 O∙L -1 ∙s -1 for flows up to 14 L∙s -1 , American Thoracic Society) negatively impacts exercise performance in healthy individuals., Methods: 16 recreationally active males (age 25 ± 1 years, height 180 ± 6 cm, weight 73.5 ± 5.8 kg, all mean ± SD) performed two incremental tests on a bicycle ergometer on each of two visits, using a metabolic cart with a flowmeter of either low (Oxycon Pro) or high (Innocor) airflow resistance. Mouth pressures, gas exchange, blood lactate concentration [La - ], perception of breathlessness, respiratory, and leg exertion were assessed throughout the tests., Results: Tests performed with the Innocor were significantly shorter (15.3 ± 3.2 vs. 15.8 ± 3.3 min, p < 0.0001) and showed higher maximal flow resistance (1.3 ± 0.2 vs. 0.3 ± 0.0 cmH 2 O∙L -1 ∙s -1 , p < 0.0001). At end-exercise, peak oxygen consumption (-200 ± 220 ml.min -1 , p < 0.0001), minute ventilation (-19.9 ± 10.5 L.min -1 , p < 0.0001), breathing frequency (-5.4 ± 5.2 breaths.min -1 , p < 0.0001), heart rate (-2.1 ± 3.6 bpm, p = 0.002) and [La - ] (-0.7 ± 1.0 mmol.L -1 , p < 0.0001), but not tidal volume (-0.1 ± 0.2 L, p = 0.172) were lower with the Innocor, while the perception of breathlessness was higher (+3.8 ± 5.1 points, p < 0.0001)., Conclusions: Airflow resistance in the upper range of current guidelines can significantly affect exercise performance and respiratory pattern in young, healthy males during incremental exercise. The present results indicate the need to revisit guidelines for devices used in ergospirometry., (© 2021 The Authors. Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)

Purpose: To examine the effects of stage duration on power output (PO), oxygen uptake (VO 2 ), and heart rate (HR) at peak level and ventilatory thresholds during synchronous arm crank ergometry., Methods: Nineteen healthy participants completed a ramp, 1-min stepwise, and 3-min stepwise graded arm crank exercise test. PO, VO 2, and HR at the first and second ventilatory threshold (VT1, VT2) and peak level were compared among the protocols: a repeated measures analysis of variance was performed to test for systematic differences, while intraclass correlation coefficients (ICC) and Bland-Altman plots were calculated to determine relative and absolute agreement., Results: Systematic differences among the protocols were found for PO at VT1, VT2, and peak level. At peak level, PO differed significantly among all protocols (ramp: 115 ± 37 W; 1-min stepwise: 108 ± 34 W; 3-min stepwise: 94 ± 31 W, p ≤ 0.01). No systematic differences for HR or VO 2 were found among the protocols. VT1 and VT2 were identified at 52% and 74% of VO 2 peak, respectively. The relative agreement among protocols varied (ICC 0.02-0.97), while absolute agreement was low with small-to-large systematic error and large random error., Conclusions: PO at VTs and peak level was significantly higher in short-stage protocols compared with the 3-min stepwise protocol, whereas HR and VO 2 showed no differences. Therefore, training zones based on PO determined in short-stage protocols might give an overestimation. Moreover, due to large random error in HR at VTs between the protocols, it is recommended that different protocols should not be used interchangeably within individuals.

Cardiopulmonary exercise testing (CPET) modalities, treadmill (TM), and cycle ergometer (CE), influence maximal gas exchange and heart rate (HR) responses. Little is known regarding CPET modality effect on submaximal biomarkers during childhood and adolescence. Ninety-four healthy participants (7-34 y.o., 53% female) performed TM and CE CPET to address two major gaps: (1) the effect of modality on submaximal CPET biomarkers, and (2) estimation of work rate in TM CPET. Breath-by-breath gas exchange enabled calculation of linear regression slopes such as V ˙ O 2 /ΔHR and Δ V ˙ E/Δ V ˙ CO 2 . Lean body mass (LBM) was measured with dual X-ray absorptiometry. We tested a novel TM CPET estimate of work rate based on TM velocity 2 , incline, and body mass (VIM). Like the linear relationship between V ˙ O 2 and work rate in CE CPET, V ˙ O 2 increased linearly with TM VIM. TM Δ V ˙ O 2 /ΔHR was highly correlated with CE (r = 0.92), and each increased substantially with LBM (P < 0.0001 for TM and CE). Δ V ˙ O 2 /ΔHR was to a small (~8.7%) but significant extent larger in TM (1.6 mL/min/beat, P = 0.04). In contrast, TM and CE Δ V ˙ E/Δ V ˙ CO 2 decreased significantly with LBM, supporting earlier observations from CE CPET. For both CE and TM, males had significantly higher Δ V ˙ O 2 /ΔHR but lower Δ V ˙ E/Δ V ˙ CO 2 than females. Novel TM CPET biomarkers such as ΔVIM/ΔHR and ∆ V ˙ O 2 /ΔVIM paralleled effects of LBM observed in CE CPET. TM and CE CPET submaximal biomarkers are not interchangeable, but similarly reflect maturation during critical periods. CPET analysis that utilizes data actually measured (rather than estimated) may improve the clinical value of TM and CE CPET., (© 2019 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.)

The purpose of this study was to investigate the use of a single 3-min all-out maximal effort to estimate anaerobic capacity (AC) through the lactate and excess post-exercise oxygen consumption (EPOC) response methods (AC [La - ]+EPOCfast ) on a cycle ergometer. Eleven physically active men (age = 28.1 ± 4.0 yrs, height = 175.1 ± 4.2 cm, body mass = 74.8 ± 11.9 kg and ⩒O 2max  = 40.7 ± 7.3 mL kg -1  min -1 ), participated in the study and performed: i) five submaximal efforts, ii) a supramaximal effort at 115% of intensity of ⩒O 2max, and iii) a 3-min all-out maximal effort. Anaerobic capacity was estimated using the supramaximal effort through conventional maximal accumulated oxygen deficit (MAOD) and also through the sum of oxygen equivalents from the glycolytic (fast component of excess post-exercise oxygen consumption) and phosphagen pathways (blood lactate accumulation) (AC [La - ]+EPOCfast ), while during the 3-min all-out maximal effort the anaerobic capacity was estimated using the AC [La - ]+EPOCfast procedure. There were no significant differences between the three methods (p > 0.05). Additionally, the anaerobic capacity estimated during the 3-min all-out effort was significantly correlated with the MAOD (r = 0.74; p = 0.009) and AC [La - ]+EPOCfast methods (r = 0.65; p = 0.029). Therefore, it is possible to conclude that the 3-min all-out effort is valid to estimate anaerobic capacity in physically active men during a single cycle ergometer effort.

Purpose: This study aimed to develop a prediction model for peak oxygen uptake ((Equation is included in full-text article.)O2peak) in children with spina bifida (SB), considering peak workload (Wpeak), peak heart rate, age, sex, anthropometric measures, walking level, physical activity level, and level of the lesion., Methods: Data of 26 participants with SB performing a graded arm crank test were used to develop the prediction model. An unrelated data set of participants with SB was used for validation., Results: The following equation was developed to predict (Equation is included in full-text article.)O2peak of participants with SB: (Equation is included in full-text article.)O2peak (mL/min) = 194+18 × Wpeak - 110 × sex (adjusted R(2) = 0.933, SEE = 96 mL/min). Bland-Altman analysis showed a nonsignificant mean difference between the measured and predicted values of (Equation is included in full-text article.)O2peak (-0.09 L/min) and limits of agreement of -0.4036 and 0.2236 L/min., Conclusions: The prediction model shows promising results; however, further validation using the same protocol is warranted before implementation in clinical practice.

Our experimental approach included two studies to determine discriminative validity and test-retest reliability (study 1) as well as ecological validity (study 2) of a judo ergometer system while performing judo-specific movements. Sixteen elite (age: 23 ± 3 years) and 11 sub-elite (age: 16 ± 1 years) athletes participated in study 1 and 14 male sub-elite judo athletes participated in study 2. Discriminative validity and test-retest reliability of sport-specific parameters (mechanical work, maximal force) were assessed during pulling movements with and without tsukuri ( kuzushi ). Ecological validity of muscle activity was determined by performing pulling movements using the ergometer without tsukuri and during the same movements against an opponent. In both conditions, electromyographic activity of trunk (e.g., m. erector spinae) and upper limb muscles (e.g., m. biceps brachii) were assessed separately for the lifting and pulling arm. Elite athletes showed mostly better mechanical work, maximal force, and power (0.12 ≤ d ≤ 1.80) compared with sub-elite athletes. The receiver operating characteristic analysis revealed acceptable validity of the JERGo © system to discriminate athletes of different performance levels predominantly during kuzushi without tsukuri (area under the curve = 0.27-0.90). Moreover, small-to-medium discriminative validity was found to detect meaningful performance changes for mechanical work and maximal force. The JERGo © system showed small-to-high relative (ICC = 0.37-0.92) and absolute reliability (SEM = 10.8-18.8%). Finally, our analyses revealed acceptable correlations ( r = 0.41-0.88) between muscle activity during kuzushi performed with the JERGo © system compared with a judo opponent. Our findings indicate that the JERGo © system is a valid and reliable test instrument for the assessment and training of judo-specific pulling kinetics particularly during kuzushi movement without tsukuri .

Brain-derived neurotrophic factor (BDNF) is suggested to play a key role in moderating the benefits of physical activity (PA) on cognition. Previous research found that PA may have an impact on peripheral BDNF expression. The aim of our study was to analyze the association between objectively measured PA with circulating BDNF in a group of active adolescents. Two hundred thirty-four adolescents (132 boys) aged 13.9 ± 0.3 years old from the DADOS study were included in this cross-sectional analysis. PA was assessed by GENEActiv triaxial accelerometer. Participants wore the accelerometer on their non-dominant wrist for 6 consecutive 24-h days, including weekends. PA was expressed as the average (min/day) of light, moderate, and vigorous PA. Fasting plasma BDNF concentrations at rest were measured using an enzyme-linked immunosorbent assay. Partial correlations and linear regression analyses were performed with a significance level established at p < 0.05. No correlations were found between BDNF and PA variables. Plasma levels of BDNF at rest were not significantly associated with daily PA in either boys or girls (p > 0.05). Based on previous research and our own data, the association between daily PA and baseline levels of BDNF remains inconclusive. Further research is needed to shed light on the relationship between regular PA and BDNF in adolescents.

Exercise testing belongs to the most important cardiologic diagnostic prozedures. Even if sensitivity and specifity of ergometry are low, it is used widely for the following: screening for coronary artery disease, as a component of imaging and cardiopulmonary exercise testing, for assessment of arrhythmias, hypertension and congenital heart diseases., Competing Interests: Disclosure The authors report no conflicts of interest in this work., (© Georg Thieme Verlag KG Stuttgart · New York.)

Background: Older adults with Alzheimer's disease (AD) may be unable to perform treadmill testing due to balance issues. We investigated whether older adults with AD could successfully complete a peak cycle ergometer test., Methods: Peak oxygen consumption (peak [Formula: see text]) assessed via a cycle ergometer test in 44 participants with AD (age 78.4 ± 6.8). Physical function was assessed via the incremental shuttle walk, 6-minute walk, and the Short Physical Performance Battery (SPPB)., Results: All participants completed the cycle ergometer test successfully. Peak [Formula: see text] was correlated with SPPB ( r = .35, P = .023), shuttle walk ( r = .35, P = .024), 6-minute walk ( r = .31, P = .05), and inversely with age ( r = -.4, P = .009). There was no correlation between peak [Formula: see text] and cognition., Conclusion: Older adults with AD are able to safely complete a peak cycle ergometer exercise testing protocol. We provide an individualized cycle ergometer test for determining aerobic capacity in older adults with AD who may be unable to perform treadmill testing due to balance or gait issues.

A linear encoder measuring vertical displacement during the heel-rise endurance test (HRET) enables the assessment of work and maximum height in addition to the traditional repetitions measure. We aimed to compare the test-retest reliability and agreement of these three outcome measures. Thirty-eight healthy participants (20 females, 18 males) performed the HRET on two occasions separated by a minimum of seven days. Reliability was assessed by the intraclass correlation coefficient (ICC) and agreement by a range of measures including the standard error of measurement (SEM), coefficient of variation (CV), and 95% limits of agreement (LoA). Reliability for repetitions (ICC=0.77 (0.66, 0.85)) was equivalent to work (ICC=0.84 (95% CI 0.76, 0.89)) and maximum height (ICC=0.85 (0.77, 0.90)). Agreement for repetitions (SEM=6.7 (5.8, 7.9); CV=13.9% (11.9, 16.8%); LoA=-1.9±37.2%) was equivalent to work (SEM=419J (361, 499J); CV=13.1% (11.2, 15.8%); LoA=0.1±34.8%) with maximum height superior (SEM=0.8cm (0.6, 1.0cm); CV=6.6% (5.7, 7.9%); LoA=1.3±17.1%). Work and maximum height demonstrated acceptable reliability and agreement that was at least equivalent to the traditional repetitions measure., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The purpose of the study was to assess the validity and inter-bike reliability of 10 Wattbike cycle ergometers, and to assess the test-retest reliability of one Wattbike. Power outputs from 100 to 1000 W were applied using a motorised calibration rig (LODE) at cadences of 70, 90, 110 and 130 rev · min -1 , which created nineteen different intensities for comparison. Significant relationships (P < 0.01, r 2  = 0.99) were found between each of the Wattbikes and the LODE. Each Wattbike was found to be valid and reliable and had good inter-bike agreement. Within-bike mean differences ranged from 0.0 W to 8.1 W at 300 W and 3.3 W to 19.3 W at 600 W. When taking into account the manufacturers stated measurement error for the LODE (2%), the mean differences were less than 2%. Comparisons between Wattbikes at each of the nineteen intensities gave differences from 0.6 to 25.5 W at intensities of 152 W and 983 W, respectively. There was no significant difference (P > 0.05) between the measures of power recorded in the test-retest condition. The data suggest that the Wattbike is an accurate and reliable tool for training and performance assessments, with data between Wattbikes being able to be used interchangeably.

Purpose: To assess the validity of power output settings of the Wahoo KICKR Power Trainer (KICKR) using a dynamic calibration rig (CALRIG) over a range of power outputs and cadences., Methods: Using the KICKR to set power outputs, powers of 100-999 W were assessed at cadences (controlled by the CALRIG) of 80, 90, 100, 110, and 120 rpm., Results: The KICKR displayed accurate measurements of power of 250-700 W at cadences of 80-120 rpm with a bias of -1.1% (95% limits of agreement [LoA] -3.6% to 1.4%). A larger mean bias in power was observed across the full range of power tested, 100-999 W (4.2%, 95% LoA -20.1% to 28.6%), due to larger biases of 100-200 and 750-999 W (4.5%, 95% LoA -2.3% to 11.3%, and 13.0%, 95% LoA -24.4% to 50.3%), respectively., Conclusions: Compared with a CALRIG, the KICKR has acceptable accuracy reporting a small mean bias and narrow LoA in the measurement of power output of 250-700 W at cadences of 80-120 rpm. Caution should be applied by coaches and sports scientists when using the KICKR at power outputs of <200 W and >750 W due to the greater variability in recorded power.

The minimum exercise intensity that elicits ⩒O2max (i⩒O2max) is an important variable associated with endurance exercise performance. i⩒O2max is usually determined during a maximal incremental exercise test; however, the magnitude and duration of the increments used influence the i⩒O2max value produced by a given test. The aims of this study were twofold. The first was to investigate whether the i⩒O2max value produced by a single cycle ergometer test (i⩒O2max(S)) was repeatable. The second was to determine if i⩒O2max(S) represents the minimum intensity at which ⩒O2max is elicited when compared to a refined i⩒O2max value (i⩒O2max(R)) derived from repeated tests. Seventeen male cyclists (age 33.9 ± 7.7 years, body mass 80.9 ± 10.2 kg, height 1.82 ± 0.05 m; VO2max 4.27 ± 0.62 L min(-1)) performed four maximal incremental tests for the determination of i⩒O2max(S) and i⩒O2max(R) (3 min stages; 20 W increments). Trials 1 and 2 were identical and used for assessing the repeatability of i⩒O2max(S), trials 3 and 4 began at different intensities and were used to determine i⩒O2max(R). i⩒O2max(S) showed good test-retest repeatability for i⩒O2max (CV = 4.1%; ICC = 0.93), VO2max (CV = 6.3%; ICC = 0.88) and test duration (CV = 6.7%; ICC = 0.89). There was no significant difference between i⩒O2max(S) and i⩒O2max(R) (303 ± 40 W vs. 301 ± 42 W) (P < .05). The present results suggest that i⩒O2max determined directly during a maximal incremental test is repeatable and provides a very good estimate of the minimum exercise intensity that elicits ⩒O2max.

The given research is devoted to the comprehensive investigation of physical working capability within the whole range of accessible loads in healthy schoolchildren aged of 7-8 years (n=159). During the working process there were identifiedfive important facts determining the structure ofpupils ’physical working capability in the researched aged group. They include common working capability, aerobic alactant working capability, anaerobic glycolytic working capability, aerobic power and aerobic volume. The pointed out facts except the fact of common working capability, are associated with the maximum, sub maximum, large and medium zones of relative capacity respectively. During the study there were found out the expressed differences between boys and girls according to the development level of aerobic and anaerobic components ofphysical working capability. Therewith the most substantial differences were observed concerning the variables characterizing the working capability in zones of large and medium power dealing predominantly with aerobic muscle activity power supply, and the least valuable ones - in accordance with working indices in the sub maximum power dealing with anaerobic glycolytic system. The received data can be applied in solving practical problems of hygienic rating and control ofphysical loads value of different relative power during the process of physical education as well as in prenosological diagnostics of children’s health on the base of the evaluation of their organism’s adaptative capabilities.

Healthcare services increasingly use the activity recognition technology to track the daily activities of individuals. In some cases, this is used to provide incentives. For example, some health insurance companies offer discount to customers who are physically active, based on the data collected from their activity tracking devices. Therefore, there is an increasing motivation for individuals to cheat, by making activity trackers detect activities that increase their benefits rather than the ones they actually do. In this study, we used a novel method to make activity recognition robust against deceptive behavior. We asked 14 subjects to attempt to trick our smartphone-based activity classifier by making it detect an activity other than the one they actually performed, for example by shaking the phone while seated to make the classifier detect walking. If they succeeded, we used their motion data to retrain the classifier, and asked them to try to trick it again. The experiment ended when subjects could no longer cheat. We found that some subjects were not able to trick the classifier at all, while others required five rounds of retraining. While classifiers trained on normal activity data predicted true activity with ~38% accuracy, training on the data gathered during the deceptive behavior increased their accuracy to ~84%. We conclude that learning the deceptive behavior of one individual helps to detect the deceptive behavior of others. Thus, we can make current activity recognition robust to deception by including deceptive activity data from a few individuals.

Background: The search for quality requires assessment tools in the various subdivisions of a health complex. In diagnostic medicine, they are scarce and in ergometry suggestions of indicators were not found., Objective: To establish indicator for quality control on ergometry based on III Guidelines of the Brazilian Cardiology Society About Ergometric Test; to verify the percentage of tests that have presented the indicator within the compliance in two services of the same institution before and after the publication of the document., Methods: A critical analysis of the guidelines in the search for indicator that would present: accuracy, reliability, simplicity, validity, sensitivity and ability to quantitatively measure the variations in the behavior of quality criteria and that would be applicable to all tests. The indicator was applied in tests of 2010 and 2011 prior to the publication, and after it was adopted by two services of the same institution., Results: The indicator that has met the criteria was the percentage of ergometric tests with exercise duration between 8 and 12 minutes. In the years 2010 and 2011, respectively, the percentage of ergometric tests within compliance were 85.5% and 86.1% (p=0.068) at the General Hospital, and 81.5% and 85.7% (p<0.001) the Service of Periodic Health Assessment., Conclusion: The exercise time between 8 and 12 minutes can be used as a quality criterion in ergometric and services where it was applied, at least 80% of the ergometric tests were compliant.

Background: We evaluated the left ventricular (LV) performance in patients with heart failure and preserved ejection fraction (HFPEF) during exercise as compared to those with heart failure and reduced ejection fraction (HFREF) and healthy subjects., Methods: All subjects received echocardiographic (Vivid7, GE Healthcare) examination with symptom-limited exercise testing on a semi-recumbent and tilting bicycle ergometer (Lode BV, Netherlands). The exercise images for 2-dimensional (2D) speckle tracking were acquired with heart rate of 90-100 bpm, while exercise images for tissue Doppler imaging (TDI) and M-mode echocardiography were stored with attainment of >85% of maximal age-predicted heart rate., Results: Stress echocardiographic examinations were performed in 40 HFPEF (aged 65 ± 9 years; 53% male), 40 HFREF (aged 62 ± 9 years; 90% male) and 30 normal controls (aged 56 ± 5 years; 33% male). Trends of progressive decline in 2D global longitudinal, circumferential and radial strains (GLS, GCS and GRS); TDI septal s' and Sm; and M-mode mitral annular plane systolic excursion (MAPSE) were observed from control, HFPEF to HFREF groups (p<0.05 for all). LV twist was preserved in HFPEF but reduced in HFREF patients as compared to normal controls (p<0.05). Diastolic function measured by TDI septal e', Em and septal E/e' progressively decreased from controls, HFPEF to HFREF patients (all p<0.05). Stroke volumes and cardiac indices (LVSI & LVCI) were preserved in HFPEF but deteriorated in HFREF than controls., Conclusions: This study provides the reference values of LV performance during exercise in HFPEF and knowledge about these changes provide important insights for future clinical studies., (© 2013.)

Background: The prolonged and frequent use of laparoscopic equipment raises ergonomic risks that may cause physical distress for surgeons. We aimed to assess the prevalence of urologic surgeons' physical distress associated with ergonomic problems in the operating room (OR) and their awareness of the ergonomic guidelines in China., Methods: A sample of 300 laparoscopic urologists in China was assessed using a questionnaire on demographic information, ergonomic issues in the OR, musculoskeletal symptoms, and awareness of the ergonomic guidelines for the OR., Results: There were 241 survey respondents (86.7%) with valid questionnaires. Among the respondents, only 43.6% placed the operating table at pubic height during the actual operation. The majority of the respondents (63.5%) used only one monitor during the procedure. Only 29.9% placed the monitor below the eye level. More than half of the respondents (50.6%) preferred to use manual control instead of the foot pedal. Most of the respondents (95.0%) never used the body support. The respondents experienced discomfort in the following regions, in ascending order: leg (21.6%), hand (30.3%), wrist (32.8%), shoulder (33.6%), back (53.1%), and neck (58.1%). The respondents with over 250 total operations experienced less discomfort than those with less than 250 total operations. Most of the respondents (84.6%) were unaware of the ergonomic guidelines. However, almost all of the respondents (98.3%) regarded the ergonomic guidelines to be important in the OR., Conclusions: Most of the laparoscopic urologists were not aware of the ergonomic guidelines for the OR; hence, they have been suffering from varying degrees of physical discomfort caused by ergonomic issues. There is an urgent need for education regarding ergonomic guidelines in the OR for laparoscopic urologists in China.

Background: In order to determine physical capability, objective methods for the assessment of performance are required. Spiroergometry is well established in occupational and social medicine. The existing standard values are defined for younger adults; however patients have predominantly an older age. To determine the age-related physical capability healthy men and women at the age over 60 years were studied., Methods and Patients: 43 persons (21 ♀/22 ♂), aged 60 - 79 years were examined spiroergometrically, including lactate measurements. The results were compared with previously published standard values., Results: The maximum capacity in watts (W) for women was 98 W, and for men 155 W and declined with increasing age (♀ 60 - 69 years 100 W, ♀ 70 - 79 years 93 W; ♂ 60 - 69 years 165 W. ♂ 70 - 79 years 139 W). The maximum oxygen uptake (♀ 1476 ± 275 mL/min, ♂ 2292 ± 245 mL/min), the weight-specific oxygen uptake (♀ 21.6 ± 4.9 mL/kg/min, ♂ 28.4 ± 4.6 mL/kg/min) and the oxygen pulse (♀ 10.7 ± 2.8 mL, ♂ 16.4 ± 2.1 mL) were significantly lower in woman compared to men (p < 0.001). The maximum lactate was achieved in women with a mean value of 5.83 mmol/L, and for men of 6.58 mmol/L (p = 0.76)., Conclusions: Studies for the collection of normal values have mainly involved young people. The physiological performance parameters cannot be referred to elderly persons. In the socio-medical assessment age-related normative values should be used to determine residual capacity., (© Georg Thieme Verlag KG Stuttgart · New York.)

Introduction: The purposes of this investigation were to determine the: (1) reproducibility of the patterns of responses for electromyographic (EMG) amplitude and mean power frequency (MPF); and (2) intraclass correlation coefficient (ICC) of the EMG amplitude and MPF during three incremental cycle ergometer tests separated by 48 hours., Methods: Ten men performed incremental cycle ergometry tests to exhaustion on three separate occasions. Surface EMG signals were recorded simultaneously from the three superficial quadriceps muscles at each trial., Results: Polynomial regression indicated that, for >95% of the cases, the best-fit model was the same at each trial for EMG amplitude but not for EMG MPF. The ICC values were high for EMG amplitude but low for EMG MPF., Conclusions: These results indicate that EMG amplitude is a reliable measure of motor unit activation strategy during incremental cycle ergometry, whereas the EMG MPF was unreliable., (Copyright © 2011 Wiley Periodicals, Inc.)

Background and Aims: The validity of five brands of cycle ergometers was evaluated by the comparison of the Vo(2) requirements at different displayed power., Methods and Results: Five physically active men performed a continuous incremental exercise test on five ergometers (Ergomeca, Lifecycle, Monark, Polar S710 and CompuTrainer). The latter was also compared with a standard dynamometer in order to associate Vo(2) values with the real power. Every test started with a 5-min warm-up on the same cycle ergometer (Ergomeca) at 100 W to make sure that the Vo(2) differences do not come from Vo(2) measurement error. Only last minute steady-state Vo(2) values of each 2-min stage were used for the Vo(2)-watt curve. Large differences (5- 10 ml kg(-1) min(-1)) at the same displayed power indicate inaccuracy of displayed power output (PO). Using corrected power values from the dynamometer revealed that for the same Vo(2) the CompuTrainer underestimates PO by approximately 30 W between 100 and 300 W, whereas the Lifecycle overestimate it by 3-53 W from 100 to 300 W. The Monark and Polar S710 underestimate PO by 15 W and the Ergomeca by approximately 5 W., Conclusion: Inaccuracies between -10% and 18% in displayed PO of various cycle ergometers question their interchangeability.

Objectives: In this study, the relationship between inter-instrument differences in regard to the daily number of steps with the intensity distribution of daily physical activity in younger and older adults was examined., Methods: 17 younger individuals and 28 older individuals wore two pedometers (Lifecorder (LC) and EC-200 (YM)) simultaneously for 7 days, in order to determine the number of steps each took. Furthermore, LC determined the time spent in light, moderate and vigorous physical activity, corresponding to <3 metabolic equivalent (METs), 3 to 6 METs and >6 METs, respectively., Results: The LC detected a significantly larger number of steps than YM (p<0.001), yet there was a strong relationship between the two measurements (r = 0.962, p<0.001). The interdevice difference with the number of steps significantly decreased in inactive older individuals compared with the active older and younger individuals, and it was also significantly negatively correlated with the time spent in light-intensity physical activity (LPA) (r = 0.523, p<0.01)., Conclusion: This study showed that the interdevice difference with the number of steps significantly increased in older participants due to the greater length of time spent in LPAs.

Objective: In this study, we investigated the accuracy of measuring walking steps with commercially available pedometers and an accelerometer-based step-counter in normal and overweight children. Our primary hypothesis was that commercially available pedometers are not an accurate measure of walking steps in normal and overweight children while walking. Our secondary hypothesis was that the accelerometer-based step-counter provides an accurate measure of walking steps in normal and overweight children., Methods: Thirteen boys (11 +/- 1 years) and 14 girls (11 +/- 1 years) who ranged in BMI from 15 to 27 kg/m(2) (16 normal and 11 overweight or obese) were recruited. Each child wore 4 pedometers at the waist and 1 accelerometer-based step-counter on each ankle. Steps were manually counted and energy expenditure was measured while the child walked on the treadmill at 0.5, 1.0, 1.5, and 2.0 mph, each for 5 minutes. The step-counting devices were also validated while children walked on level ground at a self-selected pace., Results: For the commercially available pedometers at the lowest speed of 0.5 mph, the percentage error approximated 100% for both of the pedometers. At the fastest speed of 2.0 mph, the percentage error approximated 60%. Conversely the accelerometer-based step-counter showed a percentage error of 24% +/- 22% (mean +/- SD) at 0.5 mph; however, as walking speed increased, the error declined to 5% +/- 8% at 1.0 mph, 4% +/- 5% at 1.5 mph, and 2% +/- 2% at 2.0 mph. The relationship between steps counted and walking energy expenditure showed good linear correlation., Conclusions: Commercially available pedometers are less accurate for measuring walking and require discretion in their use for children. The accuracy of the accelerometer-based step-counter enables it to be used as a tool to assess and potentially promote physical activity in normal and overweight children.

Pedometers are cheap and easy to handle devices that have proven their accuracy to measure the number of steps taken during a time period (day or week). However, at lower walking speeds and if used by obese persons the accuracy of several pedometers decreases significantly. Pedometers are not able to record the intensity of daily physical activity. In addition, the number of steps depends on age, gender, body weight and season. Nevertheless, monitoring of daily physical activity with a pedometer may be an effective method to enhance the daily physical activity of selected subgroups. For instance, subjects with an increased risk of obesity or hypertension, sedentary patients with diabetes mellitus type 2, patients with coronary heart disease and cancer patients can more easily be stimulated to become physically active and meet healthy living standards. Pedometers combined with existing effective counseling methods may be an effective strategy for many health care providers for adoption and enhancement of healthy lifestyles by sedentary patients.

Pedometers are known to have steps estimation issues. This is mainly attributed to their innate acceleration based measuring sensory. A micro-machined gyroscope (better immunity to acceleration) based pedometer is proposed. Through syntactic data recognition of apriori knowledge of human shank's dynamics and temporally précised detection of heel strikes permitted by Wavelet decomposition, an accurate and robust pedometer is acquired.

Objectives: To evaluate if inexpensive Stepping Meters are valid in counting steps in adults in free living conditions., Methods: For six days, 35 healthy volunteers wore a criterion Yamax Digiwalker and five Stepping Meters every day until all 973 pedometers had been tested. Steps were recorded daily, and the differences between counts from the Digiwalker and the Stepping Meter were expressed as a percentage of the valid value of the Digiwalker step counts. The criterion used to determine if a Stepping Meter was valid was a maximum deviation of 10% from the Digiwalker step counts., Results: A total of 252 (25.9%) Stepping Meters met the criterion, whereas 74.1% made an overestimation or underestimation of more than 10%. In more than one third (36.6%) of the invalid Stepping Meters, the deviation was greater than 50%. Most (64.8%) of the invalid pedometers overestimated the actual steps taken., Conclusions: Inexpensive Stepping Meters cannot be used in community interventions as they will give participants the wrong message.

Objective: To highlight the discrepancies in accelerometry cut-off points of moderate-to-vigorous physical activity (MVPA) according to the definitions of Puyau et al. (MVPA(P)) and Trost et al. (MVPA(T))., Research Methods and Procedures: Forty-five children from 8 to 11 years old were monitored with the ActiGraph (ActiGraph, LLC, Fort Walton Beach, FL) for 3 consecutive days. Daily time spent at MVPA obtained with MVPA(P) was compared with that obtained with MVPA(T) using variability, regression, and agreement statistics. Data were then discussed with regard to physical activity recommendations., Results: The mean daily time spent at MVPA(P) (28 +/- 18 minutes) was significantly lower (p < 10(-4)) than that spent at MVPA(T) (141 +/- 39 minutes). The coefficient of determination between the two definitions was low (R(2) = 0.49 +/- 0.71). There was a lack of agreement between the two definitions, with a mean error or bias of 113 min/d. Thirty-four point eight percent and 100% of children underwent 30-minute MVPA/d with MVPA(P) and MVPA(T) definitions, respectively., Discussion: Comparability between studies devoted to describing children's physical activity or to assessing interventions may lack consistency according to the definition, with a real risk of misclassification.

Background & Aims: Malnutrition and weight loss are common in patients with chronic obstructive pulmonary disease (COPD) and effective nutritional support relies on accurate assessment of energy requirement. This could only be performed by measuring energy expenditure using objective methods. The aim of this study was to examine the validity of the ActiReg system in assessing energy requirement in non-hospitalized patients with severe COPD, using doubly labelled water (DLW) as criterion method., Methods: Total energy expenditure (TEE) was assessed from 14 days DLW analysis in 13 patients. During the first 7 days TEE was simultaneously assessed using the ActiReg system, combining measured resting energy expenditure (REE) with physical activity monitoring., Results: A difference of -88 (782) kJ d(-1) (P = 0.69) was observed between the ActiReg system and DLW. REE explained 52% of the variation in TEE from DLW. Adding physical activity energy expenditure from the ActiReg system (PAEE(AR) = TEE(AR)-REE) increased the explained variation in TEE from DLW with 16%., Conclusions: The ActiReg system is valid in assessing energy requirement in non-hospitalized patients with severe COPD. The unique feature of being able to discriminate within both the low intensity activity range and moderate-to-high intensity activity range makes the ActiReg system a valuable tool in clinical nutritional support.

This study compared two ankle-mounted pedometers [StepWatch 3 (SW-3(Ankle)) and Activity Monitoring Pod 331 (AMP(Ankle))] and two waist-mounted pedometers [New Lifestyles NL-2000 (NL(Waist)) and Digiwalker SW-701 (SW-701(Waist))] under controlled and free-living conditions. In part I, 20 participants walked on a treadmill at speeds of 27-107 m min(-1). Actual steps were counted with a hand counter. In part II, participants performed leg swinging, heel tapping, stationary cycling, and car driving. In part III, 15 participants wore all pedometers for a 24 h period. The SW-3(Ankle) displayed values that were within 1% of actual steps during treadmill walking at all speeds. The other devices underestimated steps at slow speeds but all gave mean values that were within +/-3% of actual steps at 80 m min(-1) and above. The SW-3(Ankle) registered some steps during heel tapping, leg swinging, and cycling, while the AMP(Ankle) was only responsive to leg swinging. During car driving no devices recorded more than eight steps, on average. Over 24 h, the AMP(Ankle) recorded 18% fewer steps than the SW-3(Ankle) (P<0.05), while the SW-701(Waist) and the NL(Waist) recorded 15 and 11% less than the SW-3(Ankle), respectively (NSD). The SW-3(Ankle) has superior accuracy at slow treadmill walking speeds (although it was also more likely to detect "fidgeting" activities). Over 24 h, the SW-3(Ankle) tended to give higher estimates of steps per day than the other ankle- and waist-mounted pedometers.

Purpose: The equipment and methods used for ambulatory and home monitoring of blood pressure, lipids, coagulation, and weight management are discussed., Summary: Over 100 million people in the United States have one or more chronic diseases, such as diabetes, hypertension, and asthma. With the goal to improve health while reducing costs and the overall health care burden, ambulatory and home monitoring by pharmacists and patients are receiving more attention. Ambulatory and home monitoring of blood pressure, cholesterol, coagulation, and weight management (including devices for assessing overweight and obese patients, heart rate monitors, and pedometers) are convenient for clinicians and patients. Such monitoring provides pharmacists with an opportunity to differentiate their practices. Studies suggest that patients who are involved in ambulatory and home monitoring take a more active role in their health and may have better adherence to a prescribed diet and medication regimens. Studies also show that ambulatory and home monitoring, if done correctly, provide clinicians with a large quantity of reliable readings for future therapeutic decisions. Devices are also a means for pharmacists to increase their provision of pharmacy services. Ambulatory monitoring is billable in many clinic settings, and the devices can be a profitable addition to prescription services., Conclusion: Many devices are available to assist patients and clinicians in monitoring blood pressure, lipids, coagulation, and weight management. Familiarity with the devices will help in their proper selection and use.

Purpose: The aim of this study was to quantify pedometer-determined steps per day associated with 50, 100, and 150% of the current public health recommendation for weekly physical activity in sedentary postmenopausal women., Methods: A sample of 111 women from the DREW (Dose Response to Exercise in Women) study provided data. We randomly assigned women into one of three exercise groups expending 4, 8, or 12 kcal(-1).kg(-1).wk(-1) (KKW). Participants exercised alternately on a treadmill and recumbent cycle ergometer for a 6-month training period. Only treadmill sessions done with zero grade, at slow to moderate speeds (48-97 m.min(-1)) were used in this analysis. We controlled intensity at a HR equivalent to 50% of VO(2peak). Participants wore pedometers at baseline and throughout the study to assess their free-living physical activity (steps.d(-1)), Results: Baseline averages were <5400 steps.d(-1) for the 4-, 8-, and 12-KKW groups. During 6 months of exercise training, free-living step counts remained <5400 steps.d(-1) and did not significantly differ from baseline for each group. Average speeds and distances per exercise session were 2.7 +/- 0.4 mph, 1.2 +/- 0.2 miles (4 KKW), 2.6 +/- 0.4 mph, 2.2 +/- 0.4 miles (8 KKW), and 2.8 +/- 0.3 mph, 2.7 +/- 0.4 miles (12 KKW). This yielded 2771 (4 KKW), 5457 (8 KKW), and 6534 (12 KKW) steps per exercise session 3-4 d.wk(-1)., Conclusions: Initially sedentary postmenopausal women can meet 50% (4 KKW), 100% (8 KKW), and 150% (12 KKW) of the current public health recommendation of weekly physical activity through planned moderate-intensity walking, accumulating an average of about 2800 (50%), 5500 (100%), and 6500 steps.d(-1) (150%) 3-4 d.wk(-1).

The purpose of this study was to investigate the validity of the MetaMax II portable metabolic measurement system against the Douglas Bag technique. Nine recreationally active male subjects were included in a validation at 100 W, 10 well-trained male subjects at 200 W and 10 well-trained males at 250 W and at maximal exercise (volitional fatigue at a mean workload of 325 W). All testing was performed on an electronically braked bicycle at 60 rpm. At 100 W, the influence on MetaMax II measurements of adding a Douglas Bag breathing valve in series to the MetaMax II was investigated. The oxygen uptake was, for the MetaMax II, at 100 W mean 0.03 l x min (-1) higher (p < 0.01), at 200 W mean 0.02 l x min (-1) (n. s.) lower, at 250 W mean 0.04 l x min (-1) (n. s.) higher, and at 325 W mean 0.11 l x min (-1) (p < 0.05) higher. The carbon dioxide excretion was, for the MetaMax II, at 100 W mean 0.06 l x min (-1) (p < 0.01) lower, at 200 W mean 0.11 l x min (-1) (p < 0.05) lower, at 250 W mean 0.03 l x min (-1) (n. s.) lower, and at 325 W mean 0.16 l x min (-1) (p < 0.05) lower. The addition of a breathing valve in series to the MetaMax II resulted in lower breathing frequency, a higher ventilated tidal volume, and an affected gas measurement validation. In conclusion, the MetaMax II was found to be valid for metabolic gas measurements between 100 and at least 250 W.

Purpose: The accuracy of pedometers has not been thoroughly tested with older adult populations. The purpose of the present study was to examine the effects of walking speed and gait disorders on the accuracy of Yamax pedometers with nursing home residents (NH) relative to older adults living in the community., Methods: Pedometer accuracy was evaluated against observed steps taken during a self-paced walking test (slow, normal, and fast speeds) in 26 NH residents and 28 seniors' recreation center members (SC). Devices were attached to clothing at the waist. Walking speed was ascertained from the timed walk and a gait assessment was conducted. Percent error was calculated as ([pedometer steps - observed steps]/observed steps) x 100., Results: The walking speeds of both samples increased across self-selected paces (P < 0.0001). The community-dwelling older adults walked significantly faster (P < 0.0001) in all trials and had significantly higher (P < 0.0001) gait assessment scores (indicating fewer gait problems). Gait scores were positively associated with walking speed and pedometer percent error. Pedometers significantly underestimated NH residents' observed steps taken by 74% (slow), 55% (normal), and 46% (fast) paces (P < 0.0001). In the SC sample, the instruments failed to detect 25%, 13%, and 7% of actual steps taken, respectively (P < 0.0001). The magnitude of the error was greater for NH versus SC older adults (P < 0.0001) across all trials., Conclusions: Slow walking speed and gait disorders hamper the utility of pedometers for physical activity measurement in frail seniors, such as NH residents, when worn at the usual attachment site. Pedometers, however, can be confidently used with ostensibly healthy older adult populations for both assessment and motivation purposes.

Purpose: The purpose of this study was to compare the step values of multiple brands of pedometers over a 24-h period. The following 13 electronic pedometers were assessed in the study: Accusplit Alliance 1510 (AC), Freestyle Pacer Pro (FR), Colorado on the Move (CO), Kenz Lifecorder (KZ), New-Lifestyles NL-2000 (NL), Omron HJ-105 (OM), Oregon Scientific PE316CA (OR), Sportline 330 (SL330) and 345 (SL345), Walk4Life LS 2525 (WL), Yamax Skeletone EM-180 (SK), Yamax Digi-Walker SW-200 (YX200), and the Yamax Digi-Walker SW-701 (YX701)., Methods: Ten males (39.5 +/- 16.6 yr, mean +/- SD) and 10 females (43.3 +/- 16.6 yr) ranging in BMI from 19.8 to 35.4 kg.m-2 wore two pedometers for a 24-h period. The criterion pedometer (YX200) was worn on the left side of the body, and a comparison pedometer was worn on the right. Steps counted by each device were recorded at the end of the day for each of the thirteen pedometers., Results: Subjects took an average of 9244 steps.d-1. The KZ, YX200, NL, YX701, and SL330 yielded mean values that were not significantly different from the criterion. The FR, AC, SK, CO, and SL345 significantly underestimated steps (P < 0.05) and the WL, OM, and OR significantly overestimated steps (P < 0.05) when compared with the criterion. In addition, some pedometers underestimated by 25% whereas others overestimated by 45%., Conclusion: The KZ, YX200, NL, and YX701 appear to be suitable for most research purposes. Given the potential for pedometers in physical activity research, it is necessary that there be consistency across studies in the measurement of "steps per day."

Purpose: To evaluate the reliability and variability of eight RT3 accelerometers., Methods: The RT3 were subjected to two repeated trials of six activities: rest, walking (4 and 6 km.h-1), running (8 and 10 km.h-1), and sit-stand position (20 min). One person performed all trials (female: age 24 yr, height 158.0 cm, mass 48.2 kg). Each activity lasted 12 min. The middle 10 min were taken from each 12-min trial and used as the output measure (cts.min-1). Data were analyzed for activity ( 6), monitor ( 8), and trial ( 2) effects using four three-way ANOVA: vector magnitude, X (vertical), Y (anterioposterior), and Z (mediolateral) axes., Results: Intermonitor coefficient of variation was <6% during locomotive activities, however, increased to 8-25% during sit-stand. A three-way interaction was found for vector magnitude (F35,315=88945.7, P < 0.001) and Y (F35,315=978435.6, P < 0.001) and Z axes (F35,315=103802.8, P < 0.001). A two-way activity x monitor interaction was found for the X axis (F35,315=1037787.0, P < 0.001). Follow-up tests revealed no differences between trials 1 and 2 for vector magnitude, X and Z axes. One monitor recorded significantly lower activity counts in trial 1 compared with trial 2 along the Y axis. Intermonitor differences were evident at 4, 6, 8, and 10 km.h-1 for the Y and Z axes, and at 6, 8, and 10 km.h-1 for the vector magnitude and X axis. Variability between monitors at each activity increased as intensity increased., Conclusion: Reliability of the RT3 is good; however, intermonitor variability exists. The vertical axis of the RT3 accelerometer showed the least variability and was the most reliable. It is recommended that intermonitor variability and reliability of RT3 on each axis be assessed before use.

Electronic pedometers are accurate for assessing steps taken while walking in normal weight adults but the accuracy of these devices has not been tested in overweight and obese men and women. The primary purpose of this study was to assess the accuracy of an electronic pedometer for measuring steps taken at various walking speeds in groups of adults with variations in body mass index (BMI). The secondary purpose was to determine if the manufacturer recommended position is the best placement position for overweight and obese adults. Participants were categorized into one of three BMI categories identified by the World Health Organization: normal (N = 25; < 25 kg x m(-2)), overweight (N = 24; 25 - 29.9 kg x m(-2)), or obese (N = 17; > or = 30 kg x m(-2)). Participants walked on a treadmill for 3 min at 54, 67, 80, 94, and 107 m x min(-1) for a total of 15 min. During the treadmill walking, three electronic pedometers tallied steps taken. The pedometers were placed at the waist level, one on the anterior mid-line of the thigh (front; manufacturer recommended placement), one on the mid-axillary line (side), and one on the posterior mid-line of the thigh (back). Concurrently, a researcher counted steps using a hand-tally counter. Category of BMI did not affect the accuracy of the pedometer at any walking speed (54 m x min(-1), p = 0.991; 67 m x min(-1), p = 0.556; 80 m x min(-1), p = 0.591; 94 m x min(-1), p = 0.426; 107 m x min(-1), p = 0.869). At 54 m x min(-1), the front, side, and back pedometers significantly underestimated hand-tally counted steps by 20 % (p < 0.001), 33 % (p < 0.001), and 26 % (p < 0.001), respectively. At 67 m x min(-1) the front, side, and back pedometers significantly underestimated hand-tally counted steps by 7 % (p = 0.027), 13 % (p < 0.001), 11 % (p = 0.002), respectively. The steps recorded by the electronic pedometers placed at the front, side and back of the waist were not significantly different than steps counted by the hand-tally counter at speeds of 80 m x min(-1) and higher for all subjects combined. An electronic pedometer accurately quantified steps walked at speeds of 80 m x min(-1) or faster in persons with a normal BMI and those classified as overweight or obese. The placement of the pedometer on the front, side or back of the waistband did not affect accuracy of the pedometer for counting steps.

Maximal oxygen uptake (VO2max) is an important measure of exercise tolerance and low values may have clinical significance. Our purpose was to develop the necessary statistics--prediction equations and standard errors of estimate (SEE)--so that the lower reference limit for VO2max can be predicted for men and women. The subjects were healthy, non-smoking, sedentary men (n = 115) and women (n = 115) aged 20-70 years who performed 15 W min-1 cycle ergometer exercise tests. Three equations were developed for each gender using multiple linear regression with the non-exercise predictor variables of age and height, age and mass, and age and fat-free mass (FFM). The assumptions of regression analysis were examined and the predicted residual sum of squares (PRESS) method was used to cross-validate each equation. Healthy and diseased individual subject data from the literature were used to externally validate our lower reference limit statistics. The equations developed meet the assumptions of regression analysis and have an accuracy similar to the non-exercise prediction equations in the literature with R2 values of approximately 0.581. The PRESS method revealed that the equations are generalizable, i.e. may be used in future studies without a significant loss of accuracy. The lower reference limit predictions for the healthy and diseased individual subject data from the literature produced few miscategorizations unless the subjects were obese and mass was used as a predictor variable. In conclusion, the equations and SEE generated in this study can be used to predict an accurate and valid VO2max lower reference limit for a given subject.

The aim of this study was to investigate the use of incremental ergometry determined heart rate training intensities for the control of kayak ergometer and open water kayak training. Eight well-trained male kayakers completed a maximal incremental exercise test on an air-braked kayak ergometer for the determination of LT(1) (the power output at which blood lactate concentration increased by > or = 1 mmol x L(-1)), the associated heart rate (HR-LT(1)), VO(2)peak, maximal heart rate and maximal aerobic power. Subjects then performed 20 min trials of kayak ergometry (E), open water kayaking in a single kayak (K1) and open water kayaking in a four-seat kayak (K4) at HR-LT(1). During the three trials, heart rate was continuously measured, and blood lactate concentration, rating of perceived exertion (RPE) and stroke rate were determined every 5 min. In all trials, exercise at HR-LT(1) resulted in stable blood lactate concentrations and a stable RPE. Comparison of the three trials demonstrated that the only difference was for RPE, which was lower in (K4) than in (E), (p < 0.05). The results demonstrate that the prescription of HR-LT(1) elicits similar blood lactate concentrations during kayak ergometer and open water kayak training in both single and team boats.

The doubly labeled water method for measuring total energy expenditure is subject to error from natural variations in the background 2H and 18O in body water. There is disagreement as to whether the variations in background abundances of the two stable isotopes covary and what relative doses of 2H and 18O minimize the impact of variation on the precision of the method. We have performed two studies to investigate the amount and covariance of the background variations. These were a study of urine collected weekly from eight subjects who remained in the Madison, WI locale for 6 wk and frequent urine samples from 14 subjects during round-trip travel to a locale > or = 500 miles from Madison, WI. Background variation in excess of analytical error was detected in six of the eight nontravelers, and covariance was demonstrated in four subjects. Background variation was detected in all 14 travelers, and covariance was demonstrated in 11 subjects. The median slopes of the regression lines of delta2H vs. delta18O were 6 and 7, respectively. Modeling indicated that 2H and 18O doses yielding a 6:1 ratio of final enrichments should minimize this error introduced to the doubly labeled water method.

The reliability of power in tests of physical performance affects the precision of assessment of athletes, patients, clients and study participants. In this meta-analytic review we identify the most reliable measures of power and the factors affecting reliability. Our measures of reliability were the typical (standard) error of measurement expressed as a coefficient of variation (CV) and the percent change in the mean between trials. We meta-analysed these measures for power or work from 101 studies of healthy adults. Measures and tests with the smallest CV in exercise of a given duration include field tests of sprint running (approximately 0.9%), peak power in an incremental test on a treadmill or cycle ergometer (approximately 0.9%), equivalent mean power in a constant-power test lasting 1 minute to 3 hours on a treadmill or cycle ergometer (0.9 to 2.0%), lactate-threshold power (approximately 1.5%), and jump height or distance (approximately 2.0%). The CV for mean power on isokinetic ergometers was relatively large (> 4%). CV were larger for nonathletes versus athletes (1.3 x), female versus male nonathletes (1.4 x), shorter (approximately 1-second) and longer (approximately 1-hour) versus 1-minute tests (< or = 1.6 x), and respiratory- versus ergometer-based measures of power (1.4 to 1.6 x). There was no clear-cut effect of time between trials. The importance of a practice trial was evident in studies with > 2 trials: the CV between the first 2 trials was 1.3 times the CV between subsequent trials; performance also improved by 1.2% between the first 2 trials but by only 0.2% between subsequent trials. These findings should help exercise practitioners and researchers select or design good measures and protocols for tests of physical performance.

Study Design: A direct comparison of synchronous versus asynchronous arm crank ergometry has not been carried out previously. Therefore, a comparative research design was employed., Objective: To assess the physiological responses of arm cranking when performed asynchronously (arms moving opposite to each other) versus synchronously (both arms moving in the same direction simultaneously)., Setting: A university hospital setting in Galveston, Texas, USA., Methods: Seventeen individuals between the ages of 19 and 53 years were studied, 11 with paraplegia and six with no apparent disability. Two maximal arm crank graded exercise tests were performed with the subject seated in a wheelchair. Testing consisted of both arms (1) asynchronously (reciprocally) pushing and pulling the crank handles and (2) pushing and pulling the crank handles synchronously. Each test consisted of 2 min stages starting at 20 W and increasing 10 W per stage thereafter until exhaustion. Heart rate, oxygen consumption, and minute ventilation were measured and recorded during each stage. Blood lactate levels were monitored before and after each test. Statistical analysis was performed using the multivariate Hotelling's T2 followed by post hoc univariate tests., Results: Greater power and longer test times (both groups, P<0.05) and higher post test blood lactates (nondisabled P<0.01, paraplegic P<0.05) were achieved with asynchronous cranking versus synchronous cranking. While submaximal responses were similar between the two modes of cranking, there was a tendency for all variables to be lower with asynchronous. All subjects preferred asynchronous rather than synchronous cranking., Conclusion: Despite few statistically significant differences, based on the subjective reports from all subjects, we believe there is a clinically significant difference between the two modes of cranking. The results suggest that the mode of cranking may have implications for arm crank testing, training, and functional locomotion in individuals with lower extremity impairments.

Literature describing the use of hand-held dynamometry was examined to determine whether conclusions could be drawn regarding intertester reliability. 18 studies reporting intertester reliability coefficients were found and summarized. These suggest that high intertester reliability can be obtained, but that it is in jeopardy if tester strength is low relative to the forces being measured.

The present investigation examined the reliability of a derived strength measurement and also how variability between test sessions affects the utility of this variable for judging an individual's muscular effort. 31 young healthy men (M age = 25 yr.) completed three isometric and isokinetic concentric contractions of the knee extensors, using maximal and self-selected submaximal efforts, on each of two test sessions. Difference scores between isometric and isokinetic measurements were calculated by subtracting the mean of the three isokinetic peak torques from the mean of the three isometric peak torques for each individual subject for maximal and submaximal efforts performed on both test sessions. For the group of subjects, difference scores were significantly greater during maximal (33 +/- 29 Nm) than submaximal (13 +/- 30 Nm) efforts, suggesting subjects could not maintain the same relationship between isometric and isokinetic muscular actions across the maximal and submaximal conditions. However, the test-retest reliability of the difference scores was only modest even when data were averaged over two test sessions (intraclass correlation coefficients were .82 for maximal, and .58 for submaximal). As a result, the range of scores within which an individual's true score might be expected to lie was large (+/- 25 Nm for maximal, and +/- 37 Nm for submaximal). Although derived strength parameters like difference scores may be effective in distinguishing submaximal from maximal efforts completed by groups of subjects, the test-retest reliability of the present scores suggests that their use in judging an individual's performance may be limited.

Measurements of strength from six muscle groups described in two previously completed reports were analyzed further using Cronbach alpha. The coefficients were greater than .948 for a small sample of stroke patients and a larger sample of healthy individuals. This finding shows in diverse samples that the measures possess internal consistency and are measuring the same underlying construct.