Validity and Reproducibility of a New Treadmill Protocol: The Fitkids Treadmill Test. Med. Sci. Sports Exerc., Vol. 47, No. 10, pp. 2241–2247, 2015. Purpose: This study aimed to investigate the validity and reproducibility of a new treadmill protocol in healthy children and adolescents: the Fitkids Treadmill Test (FTT). Methods: Sixty-eight healthy children and adolescents (6–18 yr) were randomly divided into a validity group (14 boys and 20 girls; mean T SD age, 12.9 T 3.6 yr) that performed the FTT and Bruce protocol, both with respiratory gas analysis within 2 wk, and a reproducibility group (19 boys and 15 girls; mean T SD age, 13.5 T 3.5 yr) that performed the FTT twice within 2 wk. A subgroup of 21 participants within the reproducibility group performed both FTT with respiratory gas analysis. Time to exhaustion (TTE) was the main outcome of the FTT. Results: V˙ O2peak measured during the FTT showed excellent correlation with V˙ O2peak measured during the Bruce protocol (r = 0.90; P G 0.01). Backward multiple regression analysis provided the following prediction equations for V˙ O2peak (LIminj1) for boys and girls, respectively: V˙ O2peak FTT ¼ j0:748 þ ð0:117 TTEFTTÞ þ ð0:032 bodymassÞ þ 0:263, and V˙ O2peak FTT ¼ j0:748 þ ð0:117 TTEFTTÞ þ ð0:032 bodymassÞ [R2 ¼ 0:935; SEE ¼ 0:256LI min j1]. Cross-validation of the regression model showed an R2 value of 0.76. Reliability statistics for the FTT showed an intraclass correlation coefficient of 0.985 (95% confidence interval, 0.971–0.993; P G 0.001) for TTE. Bland–Altman analysis showed a mean bias of j0.07 min, with limits of agreement between +1.30 and j1.43 min. Conclusions: Results suggest that the FTT is a useful treadmill protocol with good validity and reproducibility in healthy children and adolescents. Exercise performance on the FTT and body mass can be used to adequately predict V˙ O2peak when respiratory gas analysis is not available.
DOCUMENT
Background There currently is no field test available for measuring maximal exercise capacity in people with stroke. Objective To determine the feasibility, reproducibility and validity of the Shuttle Test (ST) to measure exercise capacity in people with stroke. Design Longitudinal study design. Setting Rehabilitation department, day care centres from a nursing home and private practices specialized in neuro rehabilitation. Subjects People with subacute or chronic stroke. Interventions A standardized protocol was used to determine feasibility, reproducibility and validity of the 10-meter Shuttle Test (10mST). Main measures Number of shuttles completed, 1stVentilatory Threshold (1stVT). Results The associations of the number of shuttles completed and cardiopulmonary capacity as measured with a portable gas analyser were r > 0.7, confirming good convergent validity in subacute and chronic people with stroke. Criterion validity, however, indicates it is not a valid test for measuring maximal cardiopulmonary capacity (VO2max). Only 60% of participants were able to reach the 1stVT. Higher cardiopulmonary capacity and a higher total score of the lower extremity Motricity Index contributed significantly to a higher number of shuttles walked (p = 0.001). Conclusions The Shuttle Test may be a safe and useful exercise test for people after stroke, but may not be appropriate for use with people who walk slower than 2 km/h or 0.56 m/s.
DOCUMENT
This study investigated the added value, i.e. discriminative and concurrent validity and reproducibility, of an eye-hand coordination test relevant to table tennis as part of talent identification. Forty-three table tennis players (7–12 years) from national (n = 13), regional (n = 11) and local training centres (n = 19) participated. During the eye-hand coordination test, children needed to throw a ball against a vertical positioned table tennis table with one hand and to catch the ball correctly with the other hand as frequently as possible in 30 seconds. Four different test versions were assessed varying the distance to the table (1 or 2 meter) and using a tennis or table tennis ball. ‘Within session’ reproducibility was estimated for the two attempts of the initial tests and ten youngsters were retested after 4 weeks to estimate ‘between sessions’ reproducibility. Validity analyses using age as covariate showed that players from the national and regional centres scored significantly higher than players from the local centre in all test versions (p<0.05). The tests at 1 meter demonstrated better discriminative ability than those at 2 meter. While all tests but one had a positive significant association with competition outcome, which were corrected for age influences, the version with a table tennis ball at 1 meter showed the highest association (r = 0.54; p = 0.001). Differences between the first and second attempts were comparable for all test versions (between −8 and +7 repetitions) with ICC 's ranging from 0.72 to 0.87. The smallest differences were found for the test with a table tennis ball at 1 meter (between −3 and +3 repetitions). Best test version as part of talent identification appears to be the version with a table tennis ball at 1 meter regarding the psychometric characteristics evaluated. Longitudinal studies are necessary to evaluate the predictive value of this test.
MULTIFILE
Although cardiorespiratory fitness (CRF) is being recognized as an important marker of health and functioning, it is currently not routinely assessed in daily clinical practice. There is an urgent need for a simple and feasible exercise test that can validly and reliably estimate an individual’s CRF. The Steep Ramp Test (SRT) is such a practical short-time exercise test (work rate increments of 25 W/10 seconds, so the test phase will only take up to 4 minutes) on a cycle ergometer, that does not require expensive equipment or specialized knowledge, and has been found able to validly and reliably estimate an individual’s CRF. Although the SRT is already frequently used in the Netherlands to evaluate CRF, sex- and age-specific reference values for adults and elderly are lacking thus far, which seriously limits the interpretation of test results.
Structural and functional knowledge of proteins, which are essential in biological processes, is fundamental for our understanding of the Chemistry of Life. Structural biology - the field that studies the structure and function of proteins – has seen several revolutions over the last few years. Single particle analysis (SPA), where individual macromolecular assemblies are imaged under cryogenic conditions within highly automated electron microscopes, has been used to elucidate the structures of many novel and important proteins and complexes. Deep-learning–based computational techniques provided systematic predictions of an million three-dimensional protein structures. Cryo-electron tomography (ET) combined with sub-tomogram averaging (STA) enabled the investigation of conformational states of large macromolecular complexes. We expect in situ structural biology, where macromolecular assemblies are studied within the interior of focused-ion-beam milled frozen cells, to become the next revolution in our field. Such revolution would require well prepared vitreous samples (cells, tissue slices, organoids): the sample should be cooled fast enough to prevent the formation of crystalline ice. Previously, we developed the technology to prepare SPA samples using jets of cryogenic fluid directed onto the sample. This device, the VitroJet, has been further developed into a commercial product by CryoSol-World and has been sold worldwide. Here, we wish to advance the jetting technology such that it can vitrify cells. Crucial aspects are the speed of the jets and the timing and reproducibility of the fronts of the cryogens arriving onto the sample. We will design, build, characterise and refine a next generation of the ethane cup, a core component within the VitroJet. If successful, we should be able to increase its vitrification potential as well as its reproducibility by more than one order of magnitude. This technology will enable in situ structural biology studies necessary to understand the Chemistry of Life.
