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R J Shephard

Publications and source records attributed to R J Shephard.

At least 253 records · Page 14Linked to original sources
PubMed1987

[Possibilities of training for marathon races after myocardial infarction].

The arguments against participation in marathon races after myocardial infarction are critically discussed. It can be demonstrated that most patients undergoing post-infarction rehabilitation have the physiological characteristics required to complete the necessary training. However, psychological and social considerations reduce the potential candidates to 33-50% of a typical sample, and only 1 or 2% of these would accept the demands of such an intensive training. So far, we are encouraged by the safety of marathon races for patients who are well trained and closely monitored. In addition, the influence of the training programme on smoking, serum lipid levels and heart work seems to be impressive. Participants are much less depressed, and a growing enthusiasm can be perceived in those of their colleagues who have a lesser reserve of cardiac function.

Body Temperature↗
PubMed1986

Prediction of leisure time exercise behavior among a group of lower-limb disabled adults.

The aim of this study was to predict leisure time exercise behavior among a group of 62 lower-limb disabled adults. The theory of reasoned action proposed by Fishbein (Fishbein & Ajzen, 1975) provided a framework for the study. Variables measured included the Fishbein model variables, habit, education, disability type, fitness level, and a 7-day follow-up of exercise behavior. Some 35% of the variance in exercise behavior could be explained; intention was the strongest predictor (.31, p less than .05). In comparison, the ability to predict intentions to exercise by using the other variables was quite poor, with only 7% of the variance explained by habit. None of the Fishbein model variables contributed to this prediction. These results indicated the importance of specific factors, such as the strength of the exercise habit and the cause of disability, on exercise behavior.

Adult↗
PubMed1986

Effects of cold stress and exercise on fat loss in females.

A Latin Square design has been used to test the responses of 24 relatively fit young women to 200 minute bouts of exercise performed over 5 day trials under each of three different ambient conditions: 15 degrees C (warm-warm; (WW)); -20 degrees C while inhaling, from a facemask, air heated to 18 degrees C (cold-warm; (CW)); and -20 degrees C (cold-cold; (CC)). In both of the cold environments, special clothing and boots were provided (insulation 0.47 degree C X watt-1 X m-2 and 0.62 degree C X watt-1 X m-2; (4 and 3 CLO units)). All three trials led to a small (0.6-0.7 degree C) rise of rectal temperature, but in the two cold environments mean body temperatures fell by over 1.0 degree C. A large increase of serum ketones occurred under all conditions, and the exercise respiratory quotient suggested some increase of fat utilization, WW (0.85) through CW (0.84) to CC (0.83). A fat loss of about 0.5 kg over the five days was confirmed by hydrostatic weighing and measurement of skinfold thicknesses. This was much less than the change previously observed in men, and moreover, it seemed to be independent of ambient conditions. Possible reasons why cold did not increase fat loss in these women include: a lower relative intensity of exercise; a greater stability of fat stores in women; avoidance of caffeine; a possible translocation of subcutaneous fat to deep fat depots; and a greater desire to "lose weight" irrespective of environmental conditions.

Adipose Tissue↗
PubMed1986

Heart rate overshoot in running events.

The phenomenon of heart rate overshoot has been examined in 6 high-school athletes aged 15-16 years and in 8 university athletes aged 19-20 years. The incidence was 100% over distances of 50, 100 and 200 metres, and only one subject failed to show an overshoot following a 400 metre run. However, the overshoot was relatively larger and more long-lived following the shorter runs. While an accumulation of anaerobic metabolites seems the most likely explanation of the phenomenon over the longer distances, in the 50 metre event the Valsalva manoeuvre may also make some contribution.

Adolescent↗
PubMed1986

Accuracy of an electronic spirometer--a field trial.

Biological calibration of the Hewlett-Packard electronic spirometer against a Stead-Wells 13.5-litre spirometer shows a good concordance for forced vital capacity (FVC; systematic error 0% in women, 1% in men, probable error 4% in both sexes). However, the electronic device underestimates both 1-second forced expiratory volume (FEV1.0) and maximum mid-expiratory flow rate (MMEF) by 8-10%. This bias is unlikely to reflect technical problems of calibration, voltage drift, condensation of moisture or an inappropriate BTPS calibration; possible causes are a non-linearity in the pneumotachograph response characteristics, a lower resistance to expiration in the electronic device, and greater feedback to the subject and observer with the traditional spirometer. Given reports that similar discrepancies arise with other electronic spirometers, care should be taken in overinterpreting data obtained by such devices.

Adult↗
PubMed1986

Children's perception of parental exercise: influence of sex and age.

The purpose of the study was to document children's perception of parental exercise, relating these perceptions to (1) the self-reported parents' habits of exercise, and (2) the children's own activity patterns. The subjects were 198 students of both sexes, aged 12 to 14 yr. and enrolled in school Grades 7 to 9. A standard questionnaire assessed their perceptions of parental and personal physical activity. Both parents of each subject also reported their respective levels of habitual physical activity. Congruence between the children's perceptions and the self-reported exercise habits of the opposite-sex parent differed for boys and girls, increasing for boys and decreasing for girls between Grades 7 and 9. No significant associations were observed between the children's perception of parental exercise patterns and their own like habits. This suggests that during adolescence parental influences are minimized by other factors, personal or environmental.

Adolescent↗
PubMed1986

Physical training for the elderly.

Current activity patterns and fitness status of the average senior citizen are explored and contrasted with the condition of the elderly international competitor. The response to training and how it is modified by age, disease, and medication are discussed. An optimum training regimen is proposed, and specific precautions and contraindications to training are noted.

Aged↗
PubMed1985

The value of physical fitness in preventive medicine.

Physical conditioning induces many favourable changes in the body, including an increase of maximum oxygen transport, a decrease of body fat, a strengthening of muscles, tendons and bones, an improvement of blood lipid profile, and a better balance between oxygen demand and supply in the myocardium. The preventive value of such changes is often seen in measures of perceived health or their practical consequences. Industrial fitness programmes apparently reduce the use of medical services (physician visits and hospital days), with gains of productivity, a lessening of absenteeism, and a lower employee turnover. Techniques such as the Canadian Health Hazard Appraisal questionnaire suggest a general reduction in 'risk-taking' behaviour among exercise-class participants, with a substantial reduction in their 'appraised' age. There is little evidence that regular moderate exercise can alter the response to acute disease, but both theoretical considerations and epidemiological data suggest the value of physical activity in preventing manifestations of ischaemic heart disease, obesity and maturity onset diabetes, cholecystitis, hypertension, certain neuroses, and age-related pathologies. A fit individual is also at a lesser risk of industrial injury, and is capable of living independently for a longer fraction of his or her old age. It is concluded that physical activity is one of the more useful tactics of preventive medicine; the current challenge to both research workers and policy makers is to carry this message beyond the white-collar executive to such target groups as blue-collar workers, ethnic minorities, housewives, the elderly and the handicapped.

Acute Disease↗
PubMed1985

The "unisex phantom," sexual dimorphism, and proportional growth assessment.

The "unisex phantom" tactic of Ross and associates attempts to examine proportional growth, expressing body measurements relative to a phantom created from arbitrary mean dimensions and the observed coefficients of variation for an arbitrary sample of adult men and women. Fundamental assumptions of the model are (1) that data treated in unisex fashion have the normal distribution required of Z-type statistics throughout the period of growth, and (2) that it is reasonable to consider anthropometric measurements in all populations (regardless of ultimate size) as growing toward the common height chosen for the phantom. The validity and possible usefulness of this approach has been tested using anthropometric data collected on 546 francophone primary school children from the Trois Rivières district who had been measured repeatedly from 6 to 12 years of age. Over this age range, the mixing of data for girls and boys does not create a bimodal distribution, and has only a marginal effect upon skewing and kurtosis; however, the requirement of a normal distribution is not satisfied by quite a number of common anthropometric measurements even at this age. Moreover, application of the unisex phantom procedure to the Trois Rivières sample does little to clarify anticipated sex-related differences in regional growth, and it is argued that univariate standardization against a power function of an arbitrary adult height may not provide the best method of examining the multivariate problem of growth. Comparison of results with data from Saskatoon, previously treated by unisex phantom methodology, reveals puzzling inconsistencies; it is suggested that interlaboratory differences of methodology rather than ethnic differences are responsible for apparent discrepancies in growth patterns. It is urged that interlaboratory validation of techniques and landmarks should precede the ascription of apparent differences in body build to constitutional factors.

Anthropometry↗