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Biomedical subjects

V Ben-Ezra

Publications and source records attributed to V Ben-Ezra.

5 recordsLinked to original sources

Influence of selected reinforcers on the cardiorespiratory exercise behavior of profoundly mentally retarded youth.

6 profoundly mentally retarded youth were provided a 5-wk. stair-climbing program to improve cardiorespiratory fitness behavior. Three subjects were provided verbal plus food reinforcement and the other three received verbal reinforcement during the intervention phase. Based on the visual inspection of the data, both types of reinforcement increased the number of steps taken and exercise time.

Exercise

Use of reinforcement to increase independence in physical fitness performance of profoundly mentally retarded youth.

The purpose of this study was to examine the influence of verbal praise and verbal praise plus music or vibratory reinforcement on the level of independent performance on abdominal strength and endurance, lower back and hip flexibility, and upper body strength/endurance exercises of 12 profoundly mentally retarded, ambulatory youth, ages 10 to 18 years. A single-subject AB design with a control group was used to assess the difference in performance of physical fitness under the baseline condition of no reinforcement and under the two experimental conditions of verbal praise and verbal praise plus music or vibratory reinforcement. In contrast to previous results reported in the literature, verbal praise and verbal praise plus music or vibratory reinforcement were not effective in increasing the level of independence in performing selected physical fitness tasks.

Adolescent

Step ergometry: is it task-specific training?

Maximal exercise responses were measured before and after 10 weeks of training in two groups of men, one trained on a treadmill (n = 12) and the other on a step ergometer (n = 9); the groups were pre- and post-tested on both machines to examine the specificity of the training modes. Training for both groups consisted of 3 days week-1, 30 min day-1, progressing to 50 min day-1, at an intensity of 75%-80% heart rate maximum reserve. Pre-training maximal oxygen uptake (VO2max) was significantly higher on the treadmill for both groups (X = 8.5%). VO2max increased 6.9% on the treadmill (P less than 0.05) and 6.9% (P greater than 0.05) on the step ergometer after treadmill training. The small increases may be attributed to the specificity of the testing protocols used to elicit VO2max. Significant (P less than 0.01) increases in VO2max were found for both modalities after step-ergometry training (treadmill = 11.8%; step ergometer = 23.2%). These increases resulted in equal post-test VO2max values (4.05 l min-1; 51 ml kg-1 min-1) on the step ergometer and treadmill. The significant increases in VO2max found for both modalities after step-ergometry training shows that (1) step ergometry is an effective training modality, and (2) its effects can be measured on the treadmill and therefore it is not task-specific training.

Adult

The effect of training on the norepinephrine response at rest and during exercise in 5 degrees and 20 degrees C environments.

Eleven males were examined at rest and during submaximal exercise in 5 degrees C and 20 degrees C environments to determine if the norepinephrine (NE) and other physiological responses in the cold would be altered by eight weeks of training. Blood samples were obtained at the end of 15 minutes of rest and submaximal exercise, and were assayed for NE. Pretraining resting NE levels in the 5 degrees C condition were significantly higher than those found in the 20 degrees C environment (684 +/- 89 vs 491 +/- 48 pg/ml). A significant training effect reduced resting NE levels in the 5 degrees C (502 +/- 77 pg/ml) but not the 20 degrees C (392 +/- 45 pg/ml) condition. Pre and posttraining exercise NE levels were elevated above resting in both the 5 degrees C (1477 +/- 136 vs 1559 +/- 208) and the 20 degrees C environments (1623 +/- 176 pg/ml vs 1444 +/- 224 pg/ml), but were not significantly different between conditions. Skin temperatures were significantly lower, and resting blood pressure was significantly higher in the 5 degrees C condition. These data suggest that both cold and exercise act as stimulators of NE release, but an additive effect on NE of cold and exercise does not occur. The resting NE levels pre and posttraining in the 5 degrees C condition suggest that a cross tolerance to cold stress was present.

Adaptation, Physiological

Stair climbing: an alternative exercise modality for firefighters.

The purpose of this investigation was to determine the maximal cardiorespiratory responses of firefighters to stair-climbing work and to compare these responses to maximal treadmill exercise. Thirty-eight firefighters volunteered to participate in the study. Maximal CR including oxygen consumption (VO2), ventilatory equivalent for oxygen (VE/VO2), minute ventilation (VE) and heart rate (HR) were measured during both stair climbing and graded treadmill exercise. The results showed that VO2max and HRmax were significantly lower, 7% and 2% respectively, and the VE/VO2 was significantly higher (6.7%) during the stair-climbing exercise. Maximal VE was not different between the two modes of exercise. The results suggest that since VO2max and HRmax were lower during stair climbing, the metabolic cost of firefighting tasks as related to VO2max on a treadmill may not be accurately reflected. Since stair climbing is a task-specific activity for firefighters, it is recommended that testing of firefighters be performed on a stair-climbing device, and that the difference in VO2max between treadmill and stair-climbing exercise be considered when recommending a desired fitness level for firefighters.

Adult