Biomedical subjects
K H Sidney
Publications and source records attributed to K H Sidney.
Frequency and intensity of exercise training for elderly subjects.
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Endurance training and body compostition of the elderly.
Body composition was studied in subjects from the seventh decade of life (13 M, 25F), observations being made on recruitment and at selected points over a 1-year program of endurance training. As at younger ages, the women initially had more subcultaneous fat than the men, particularly over the limbs. In both sexes, excess weights (9.3 kg. M; 8.1 kg, F) and average skinfold radings (16.2 mm, M; 21.1mm, F) were greater than in younger adults. Edurance training (1 hr of supervised exercise, 150-200 kcal persession, nominal four sessions per week) progressively reduced skinfold readings, by an average of 1.6 mm at 7 weeks, by 2.4 dependent upon the intensity and the frequency of exercise undertaken by the individual. Total body potassium (40K determinations) agreed well with previous studies of older subjects. Body fat estimated form 40K showed a fair correlation with skinfold estimates of body fat (r=0.69, M; 0.93, F), but absolute precentages were higher by 40K(36.6%, M; 48.7%, F) than by subcutaneous fat measurements (20%, M;32% F). Body potassium increased by 4% over the year of training, 70% of this change, occurring between the 14th and the 52nd week of conditioning. Small gains were also recorded in arm circumference, grip strenght (R but not L) and knee extension force. Neutron activation data showed that both sexes had lower initial bone calcium counts than sedentary middle-aged adults. The sample as a whole showed no calcium loss over the year of training, but the group taking the least exercise did show a significant loss (P less than 0.05). Modest endurance training of an elderly population seems not only to correct loss of cardiorespiratory condition, but also to induce favorable changes in body fat and lean mass.
Activity patterns of elderly men and women.
The activity patterns of elderly men and women (greater than 60 years) were examined by diaries, ECG taperecorders, and electro-chemical integrators. Although the subjects thought that they were active relative to others of their age, both activity measurements and initial assessments of fitness indicated an inactive life style. At different periods of the day, the heart rate averaged 70-90 beats per minute, and the physical training threshold was rarely approached. During the week, the women engaged in 90 min. more physical activity than the men. However, at the weekend the men added an average of 100 min. of physical activity, whereas the women carried out 30 min. less physical work. Introduction of a 1-hour physical activity class four times per week increased the average daily energy expenditure by 150-200 kCal, to 2500 kCal in the men and 2200 kCal in the women. The added activity was sufficient to augment aerobic power, to induce favorable changes in body composition and to initiate change in other areas of life style, including a diminished use of the car.
Training and electrocardiographic abnormalities in the elderly.
Electrocardiograms (CM5 lead, where one lead is attached in the V5 position and one at the manubrium sterni, with the neutral lead on the back of the neck) have been recorded from 14 men and 25 women aged 60 to 75 years, at rest, during progressive bicycle ergometer exercise to 75 to 85 per cent maximum oxygen intake, and during the subsequent recovery phase. Earlier studies showing a high frequency of ischaemic electrocardiographic abnormalities in women are confirmed; it is suggested that this may reflect a high work load per unit mass of myocardium. Training induces an elevation of the ST segment at rest and during recovery, with a reduction in ST depression during work at a given heart rate, the exercise changes being related to the intensity and frequency of training selected by the subject. Possible explanations of the response to regular exercise include not only the development of the collateral circulation, but also a lessening of the hyperkalaemia of effort and a reduction in the work load per unit mass of myocardium secondary to hypertrophy or a change in the average dimensions of the heart.
Maximum and submaximum exercise tests in men and women in the seventh, eighth, and ninth decades of life.
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Perception of exertion in the elderly, effects of aging, mode of exercise and physical training.
Ratings of perceived exertion by the Borg psychophysical scale have been made on 26 men and 30 women aged 60 to 70 yr. All were volercise lines relating the ratings of exertion to heart rate were closely similar in men and women, scores at all heart rates being 2 or 3 units higher than in young adults. A brief progressive exercise protocol on the treadmill yielded somewhat lower ratings than bicycle ergometer work, the discrepancy being marked in women. At any given oxygen intake, ratings were higher for females than malesy nd higher for old than young subjects. However, when oxygen intake was expressed as a percentage of the directly measured maximum oxygen intake, scores became independent of sex and age. A 35-wk. period of conditioning substantially reduced heart rates but had little effect on the perception of effort at a given work load. This unexpected result may reflect a closer approximation of core and skin temperatures with reduction of sub-cutaneous fat.
The effects of ephedrine on the physiological and psychological responses to submaximal and maximal exercise in man.
The purpose of this study was to determine whether a single full therapeutic dose (24 mg) of ephedrine taken orally has any effect upon physical performance and fitness. Twenty-one healthy males, aged 19-30 years, were tested on three occasions within three weeks using a double-blind modified crossover design. The effects of ephedrine were determined by comparing the differences between drug and control conditions using paired t-tests. The test battery included measures of muscle strength, endurance and power, lung function, reaction time, hand-eye coordination, anaerobic capacity and speed, cardio-respiratory endurance, and responses to maximal and submaximal effort, including maximum oxygen intake, ratings of perceived exertion and speed of recovery from effort. Despite a slight stimulating effect on blood pressure and on exercise and recovery heart rates, 24 mg of ephedrine had no effect on any of the measures of physical work capacity. Ephedrine had no effect on lung function of healthy young men, but may have assisted the learning of certain simple psychomotor tasks.
Attitudes towards health and physical activity in the elderly. Effects of a physical training program.
Attitudes towards physical activity, perceived health, body image, anxiety and life satisfaction have been studied in men and women 60 years of age and older, volunteering for progressive endurance training. Relative to other studies of younger volunteers, the senior citizens placed more value upon activity as "an esthetic experience" and as "a means to health and fitness" showing less interest in "the pursuit of vertigo." Many non-participants and "drop-outs" perceived their current fitness as satisfactory. Subjects who selected a low frequency and low intensity of training were obese, with high Cornell Medical Index (CMI) scores on both organic and psychological scales. After 14 weeks of conditioning, 83% of subjects reported improvements in well-being. However, CMI scores were reduced on only one of twelve organic scales and none of the behavior, mood and feeling scales. Neugarten's Life Satisfaction Index, Kenyon's Body Image scales, and McPherson's the Real Me scores remained unchanged, but there was a decrease of Manifest Anxiety (Taylor scale) and a greater regard of physical activity as "the relief of tension." When subjects were classed according to changes in aerobic power, between group differences were found for "Real Me" scores and for three of Kenyon's attitude scales. Persons who trained frequently and intensively showed improvements for body image and for five of Kenyon's attitude scales.
Attitudes towards health and physical activity in the elderly. Effects of a physical training program.
Attitudes towards physical activity, perceived health, body image, anxiety and life satisfaction have been studied in men and women 60 years of age and older, volunteering for progressive endurance training. Relative to other studies of younger volunteers, the senior citizens placed more value upon activity as "an esthetic experience" and as "a means to health and fitness" showing less interest in "the pursuit of vertigo." Many non-participants and "drop-outs" perceived their current fitness as satisfactory. Subjects who selected a low frequency and low intensity of training were obese, with high Cornell Medical Index (CMI) scores on both organic and psychological scales. After 14 weeks of conditioning, 83% of subjects reported improvements in well-being. However, CMI scores were reduced on only one of twelve organic scales and none of the behavior, mood and feeling scales. Neugarten's Life Satisfaction Index, Kenyon's Body Image scales, and McPherson's the Real Me scores remained unchanged, but there was a decrease of Manifest Anxiety (Taylor scale) and a greater regard for physical activity as "the relief of tension." When subjects were classed according to changes in aerobic power, between group differences were found for "Real Me" scores and for three of Kenyon's attitude scales. Persons who trained frequently and intensively showed improvements for body image and for five of Kenyon's attitude scales.
Effects of physical exercise on plasma growth hormone and cortisol levels in human subjects.
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