Maximum oxygen uptake and the running speed at the anaerobic threshold were determined during treadmill running. Performance in these laboratory tests and performance on a squash-specific field test were compared and examined with respect to subjective ratings of squash fitness.The field test was performed in a squash court. Six light bulbs were connected to a programming device causing individual bulbs to light up in a given sequence. The players were instructed to react to the flashes by running towards and striking balloons mounted in the vicinity of the bulbs. By altering the interval between the lighting of the bulbs the intensity of exercise could be varied. The test consisted of a series of 3 min periods of exercise at increasing intensities (increased number of runs per unit of time). The results showed a low correlation (r = 0.52) between treadmill ergometry data and a rank-order list based on an independent, partly subjective estimate of fitness. A higher correlation (r = 0.90) was found for the results of the field test and the rank-order list. Maximum oxygen uptake values and anaerobic threshold values derived from laboratory measurements were thus not sufficient for a valid estimate of competition fitness in these players. The results show that a valid estimate of fitness can be derived from measurements involving exercise closely resembling that which is specific for the sports activity in question. Improved training advice and guidance may result from such studies.
Only photometers scanning a large range of wavelengths provide the amount of information which is necessary to analyze multicomponent systems in a general form. After a description of a rapid scanning photometer and a discussion of the recording problems, the mathematical method is described which allows an optimal analysis of the concentrations of the single components of a multicomponent system. The error involved in this procedure is demonstrated by the calculation of the four nucleotides in a mixture. The long range photometry has been successfully applied to other problems such as measurements by reflected light and analyses of inhomogeneously distributed substances in living tissues.
The influence of different values of arterial oxygen partial pressure (PO2) on local tissue PO2 was investigated. Tissue PO2 was measured on the surface of the beating hearts of rabbit and cat by the multiwire surface electrode as described by Kessler and Lübbers (21). In parallel experiments, local hydrogen clearance applying the H2-PH2 probe (33) was used to determine the mean blood flow per area (microflow) at the capillary level. Mean blood flow per area, v, was calculated from PH2 clearance curves obtained by local application of rectangular hydrogen pulses. The results are presented as histograms. Under steady state conditions (barbiturate narcosis), tissue PO2 ranged from 5 to 65 Torr (0.67 to 8.67 kPA) with a median of 31 Torr (4.13 kPA) in the cat heart. Mean flow per area covered values between 25 and 11 mum/s with a median of 55 mum/s. For rabbit heart muscle, the median was v = 37 mum/s and the range 28 to 46 mum/s. Hyperoxia broadened the range of tissue PO2 and shifted flow per area to lower values. Different degrees of hypoxia shifted the PO2 histogram to the left (median PO2 14 Torr and 4 Torr, respectively; [1.87 kPA and 0.53 kPA]) and the flow histogram to the right.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.