M Vercruyssen — Page 2

PubMed1989

Time estimation performance before, during, and following physical activity.

An experiment is reported which evaluated performance on a 10-sec unfilled time interval estimation task before, during, and after physical work on a cycle ergometer at relative intensities of 30 and 60% VO2max. Results from eleven healthy male subjects revealed a significant increase in time estimation variability and a decrease in the mean estimated time intervals during exercise compared to non-exercise phases. These findings are part of a growing body of evidence which indicates that exercise and its severity has a substantive impact on perceptual and cognitive performance, particularly the ability to synchronize and anticipate the timing of events.

Adult↗

PubMed1988

Intraseason changes in the body composition of collegiate female gymnasts.

Body composition measures were collected pre-, mid- and post-season on a team of eight national-calibre collegiate women gymnasts to examine intraseason changes. Also analysed were interseason changes using pre- and post-season data on five of the eight subjects during the current and previous year, according to a 2 x 2 (years x tests) analysis of variance repeated-measures design. Skinfold, circumference and diameter measures were collected with percentage body fat, lean body mass and body density determined by regression equations developed specifically for collegiate female gymnasts. Intraseason body weight decreased significantly from pre- to mid-season (means = 55.0 and 53.6 kg respectively); but the difference between mid- and post-season (53.9 kg) values was not significant (P greater than 0.05). The majority of the 1.4 kg weight loss occurred during intense pre-season conditioning and not during the actual season. Percentage body fat, on the other hand, decreased significantly from pre- to mid-season and mid- to post-season (means = 21.4%, 17.4% and 13.45% respectively; P less than 0.0005). Body density increased significantly from pre- to mid-season and mid- to post-season (means = 1.0476, 1.0584 and 1.0681 respectively; P greater than 0.0005). Of the circumference and skinfold values used in calculating percentage body fat and body density, only the skinfold values displayed significant decreases throughout the season. Interseason analyses revealed no significant changes in any of the dependent measures between seasons, despite consistent trends. There were no significant years x tests interactions and all intraseason changes for two seasons (n = 5) were the same as those found in more detailed analysis of a single season (n = 8) except in the case of weight loss, which was marginally significant (P less than 0.046) in the single-season and not in the dual-season analysis (P greater than 0.05). Body composition of these gymnasts changed in many ways within competitive seasons. The most pronounced changes observed were decreases in subcutaneous fat and increases in body density. This study reinforces the need for administrators, coaches and athletes to be concerned with percentage body fat and skinfold measures rather than weight alone when determining if a person is 'fat'.

Adipose Tissue↗

PubMed1985

Hot air breathing: effects of elevated wet bulb temperatures on tissue temperatures of the mouth.

Six healthy young men breathed room air or one of nine hot humid air conditions on separate days for one hour while walking on a treadmill (40% VO2 max). Inspired wet bulb temperatures ranged from 18.9 (room air) to 49.3 degrees C. Tissue temperatures in the mouth were measured by means of thermocouples placed on the tongue and hard palate. Analysis of variance on repeated measures showed significant increases in both tongue and hard palate tissue temperatures (p less than 0.001) as a result of increasing wet bulb temperatures; however, core temperature and heart rate were not affected (p greater than 0.05). Ratings of subjective discomfort increased proportionally with increases in wet bulb temperature of the inspired air. It was concluded that wet bulb temperature of inspired air is a valuable measure to uses in studying temperature responses of mouth tissues when inhaling hot humid air, particularly when investigating human tolerance levels in order to recommend federal standards for the design of breathing apparatus.

Adult↗