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Biomedical subjects

D Q Marisi

Publications and source records attributed to D Q Marisi.

5 recordsLinked to original sources
PubMed1996

Perceived exertion during physical exercise among individuals high and low in fitness.

This study was conducted to investigate the influence of fitness level and gradually increased amounts of exercise on individuals' ratings of perceived exertion (RPE). 20 men served as paid subjects. They were divided into groups of high ( > 56 ml/kg/min.) and low fitness ( < 46 ml/kg/min.) according to their maximal oxygen uptake (VO2 (max)). Participants were required to pedal on a cycle ergometer at a progressively increased workload (every 10 min.) corresponding to 40, 50, 60, 70, and 80% of individual VO2 (max) values. Heart rates, RPE, and core temperatures were recorded every 5th minute after the initiation of exercising at a specific workload. Analysis indicated that, when controlling for VO2 (max) values, elevations of heart rate and core temperature were not affected by fitness. However, highly fit individuals perceived themselves under less exertion than did the group low in fitness. Correlations showed that, taking into consideration fitness, there is a stronger relationship between RPE and heart rate and RPE and core temperature for the highly fit individuals than for the less fit.

Adult↗
PubMed1996

Elevation of core temperature and mental functioning.

The purpose of this study was to investigate whether raised core temperature due to gradually increased amounts of exercise affects concentration and speed of information processing, 20 paid men, separated into groups of high (> 56 ml/kg/min.) and low fitness (< 46 ml/kg/min.) according to their maximal oxygen uptake (VO2max), participated in two experimental conditions (exercise and control). Concentration was measured by the Random Number Generation test of attentional deployment given every 10 min. of cycling at workloads calculated as 40, 50, 60, 70, and 80% of individual VO2max values and 10 min. after exercise cessation (exhaustion). Speed of information processing was estimated by an eight-choice reaction time/movement time task given before and after exercise and 15 min. after exercise cessation. Core temperature was recorded at the same time individuals were administered the psychological tests. Analyses indicated that core temperatures increased significantly as a function of exercise intensity for high and low fitness groups. Correlations among the psychophysiological factors indicated that increases in core temperature were not associated with mental functioning. However, at certain core temperatures, core temperature and average choice reaction time/movement time were associated with participants' fitness.

Adult↗
PubMed1995

Information processing and concentration as a function of fitness level and exercise-induced activation to exhaustion.

To examine the effects of increasing amounts of exercise on attention and speed of information processing 20 paid male subjects were separated into groups of high and low fitness according to their VO2max values. The experiment involved an attentional task (Random Number Generation) that was given after every 10 min. of cycling at work-load resistances calculated as 40%, 50%, 60%, 70%, and 80% of individual VO2max values. An eight-choice reaction time-movement time task was given before and after exercise as well as after a 15-min. recovery period. Individuals were tested within 10 min. after exercise cessation (exhaustion) for concentration and within 15 min. for choice reaction time and movement time to assess whether fitness differentially interacted with these variables. Split-plot factorial analyses of variance suggested that the CNS appeared capable of maintaining performance after 50 min. of exhaustive exercise compared to values obtained at the preexercise condition. A 15-min. recovery period significantly impaired MT but relatively highly fit individuals did not appear to perform the choice RT and concentration tasks better than individuals low in fitness.

Adult↗
PubMed1977

Genetic and extragenetic variance in motor performance.

A simple additive model of genes plus environment, based on intrapair similarities observed in 35 MZ and 35 like-sexed DZ twin pairs, was used to estimate the relative contribution of genetically controlled phenotypic variance in psychomotor individuality. Subjects practiced 50 trials on a pursuit rotor apparatus under a 20-sec/20-sec, work-rest schedule with a 30 min rest pause allowed between trials 30 and 31. Analyses of the data disclosed that a greater proportion of genetic factors, as opposed to nongenetic factors, appears to account for existing individual differences in motor performance among individuals subject to similar environmental conditions. The strength of this genetic control, however, systematically diminished throughout the course of practice obeying a monotonic trend over trials.

Adolescent↗