Determination of peak cardiorespiratory fitness parameters in children: which averaging method should we use?     

Joel Blanchard  Samuel Blais  Philippe Chetaille  Michele Bisson  François P. Counil  Thelma H. Girard 《Journal of sports sciences》2019,37(11):1265-1269

The purpose of this study was to identify which averaging methods most accurately measures peak cardiorespiratory fitness (CRF) parameters [peak O₂ uptake (VO₂), peak O₂pulse and peak respiratory exchange ratio (RER)] in a sample of healthy children and adolescents. In this cross-sectional multicenter study, we recruited 278 healthy children aged 12–17 years. We compared the mean peak value of three CRF parameters using the recommended averaging methods (30-second block average) with alternative averaging methods such as moving averages or shorter smoothing periods. We also assessed averaging methods for accuracy by individually reviewing breath-by-breath scatter plots. The 30-second block average method resulted in a lower mean peak VO₂ and in an increased proportion of underestimated peak values. Using a 30-second moving average significantly increased mean peak values which increased accuracy. Similar results were found for peak RER and peak O₂pulse. In conclusion, the currently recommended averaging method (30-second block average) increased the risk of misinterpretation of peak CRF values in children. Using a moving average approach decreased misinterpretation and increased accuracy.  相似文献   

An occlusion paradigm to assess the importance of the timing of the quiet eye fixation     

Samuel J. Vine  Don Hyung Lee  Rosanna Walters-Symons  Mark R. Wilson 《European Journal of Sport Science》2017,17(1):85-92

Abstract

The aim of the study was to explore the significance of the ‘timing’ of the quiet eye (QE), and the relative importance of late (online control) or early (pre-programming) visual information for accuracy. Twenty-seven skilled golfers completed a putting task using an occlusion paradigm with three conditions: early (prior to backswing), late (during putter stroke), and no (control) occlusion of vision. Performance, QE, and kinematic variables relating to the swing were measured. Results revealed that providing only early visual information (occluding late visual information) had a significant detrimental effect on performance and kinematic measures, compared to the control condition (no occlusion), despite QE durations being maintained. Conversely, providing only late visual information (occluding early visual information) was not significantly detrimental to performance or kinematics, with results similar to those in the control condition. These findings imply that the visual information extracted during movement execution – the late proportion of the QE – is critical when golf putting. The results challenge the predominant view that the QE serves only a pre-programming function. We propose that the different proportions of the QE (before and during movement) may serve different functions in supporting accuracy in golf putting.  相似文献   

Changes in kinematics and arm–leg coordination during a 100-m breaststroke swim     

Samuel W. Oxford  Rob S. James  Michael J. Price  Carl J. Payton  Michael J. Duncan 《Journal of sports sciences》2017,35(16):1658-1665

The purpose of this study was to compare arm–leg coordination and kinematics during 100 m breaststroke in 26 (8 female; 18 male) specialist breaststroke swimmers. Laps were recorded using three 50-Hz underwater cameras. Heart rate and blood lactate were measured pre- and post-swim. Arm–leg coordination was defined using coordination phases describing continuity between recovery and propulsive phases of upper and lower limbs: coordination phase 1 (time between end of leg kick and start of the arm pull phases); and coordination phase 2 (time between end of arm pull and start of leg kick phases). Duration of stroke phases, coordination phases, swim velocity, stroke length (SL), stroke rate (SR) and stroke index (SI) were analysed during the last three strokes of each lap that were unaffected by turning or finishing. Significant changes in velocity, SI and SL (P < 0.05) were found between laps. Both sexes showed significant increase (P < 0.05) in heart rate and blood lactate pre- to post-swim. Males had significantly (P < 0.01) faster swim velocities resulting from longer SLs (P = 0.016) with no difference in SR (P = 0.064). Sex differences in kinematic parameters can be explained by anthropometric differences providing males with increased propelling efficiency.  相似文献   

The osmium lamps     

Louis E. Levy  Samuel Sartain 《Journal of The Franklin Institute》1905,159(6):461-463

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Seasoning timber     

Samuel Clegg 《Journal of The Franklin Institute》1852,53(1):53-56

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A stated meeting of the board of managers was held at the hall of the Institute,February 11, 1830     

Samuel V. Merrick 《Journal of The Franklin Institute》1830,9(3):173-174

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The nineteenth quarterly meeting of the Franklin Institute,was held at their hall,on the 16th Oct. 1828     

Samuel J. Robbins 《Journal of The Franklin Institute》1828,6(5):352-353

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Automatic devices for extracting alkaloidal solutions: II. Application to nux vomica and belladonna alkaloids     

Howard R. Watkins  Samuel Palkin 《Journal of The Franklin Institute》1926,201(2):253-254

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Studies in the analytical chemistry of drugs. The determination of total alkaloids in nux vomica preparations     

Samuel Palkin  H.R. Watkins 《Journal of The Franklin Institute》1924,198(5):710

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The reaction of a liquid jet     

J. Brukitt Webb 《Journal of The Franklin Institute》1887,124(2):144-156

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