Development of the Canadian Home Fitness Test

The Canadian Home Fitness Test is a self-administered procedure in which the participant steps at an age- and sex-specific rhythm controlled by recorded music, then palpates the pulse immediately following activity. Validation of the test has shown a correlation of 0.72 with the results of a standard submaximum bicycle ergometer test, while the directly measured maximum oxygen intake is correlated even more closely (r = 0.88) with the attained stepping rate, body weight and recovery heart rate. Given modest training, subjects could measure their immediate postexercise heart rate (correlation with electro-cardiographic data, r = 0.94), although 10-second counts underestimated the true rate by an average of 7 beats/min. The safety of the test will be established ultimately by experience in its use in a large population; nevertheless, both theoretical considerations and results of trials in over 14 000 adults suggest the procedure can be self-administered without serious consequences. It is also well accepted by the general public and arouses considerable interest in most homes. The test can thus be recommended as providing an approximate measure of an individual''s physical fitness in order to stimulate an increase in personal physical activity. It also has potential as a simple screening procedure that would allow paramedical personnel to record fitness levels and standardized exercise electrocardiograms in large segments of the population.     

Relation between cardiorespiratory fitness and selected risk factors for coronary heart disease in a population of Canadian men and women.

OBJECTIVE: To determine the relation between cardiorespiratory fitness, as determined with the Canadian Aerobic Fitness Test (CAFT), and selected risk factors for coronary heart disease (CHD) in a Canadian population. DESIGN: Cross-sectional study. On the basis of age-specific and sex-specific national percentile scores, subjects were classified as being in the low-fitness, moderate-fitness or high-fitness category according to maximum oxygen consumption (VO2 max) predicted from performance on the CAFT. PARTICIPANTS: A total of 4082 male and 1205 female Canadian federal public servants aged 30 to 59 years who participated in a voluntary fitness testing program between 1984 and 1991. OUTCOME MEASURES: Body composition (body mass index, triceps skinfold thickness, sum of four skinfold measurements, predicted percentage of body fat and waist-hip ratio), blood lipid levels (total cholesterol, triglycerides, high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol and ratio of total cholesterol to HDL-C) and hemodynamic measurements (heart rate and blood pressure at rest and during exercise and predicted VO2 max). MAIN RESULTS: For both men and women the mean anthropometric measurements, blood lipid levels and blood pressure measurements at rest and after exercise were significantly associated with fitness category (p less than 0.05). CONCLUSIONS: In both men and women a higher level of aerobic fitness, as defined by VO2 max predicted from performance on the CAFT, is associated with a more favourable CHD risk profile. The results support the use of VO2 max predicted from performance on the CAFT as a valid procedure for classifying people according to fitness level.     

A Fitness Performance Test for School Children and its Correlation with Physical Working Capacity and Maximal Oxygen Uptake

The Canadian Association for Health, Physical Education and Recreation fitness test (CAHPER test) composed of six items was compared to two laboratory tests of endurance fitness, physical working capacity at a minute pulse rate of 170 (PWC₁₇₀) and maximum oxygen uptake (Vo₂ max.) in over 500 Winnipeg school children of both sexes aged 6 to 17 years. CAHPER test results were similar to the national average published by CAHPER in a test booklet. Correlation coefficients (r) of Vo₂ max. for boys with the CAHPER tests were: sit-ups .42, broad jump .69, shuttle run .50, arm hang .43, 50-yard dash .60, 300-yard run .65; for girls the r values were about half the values for the boys. Much of the correlation between CAHPER tests and Vo₂ max. or PWC₁₇₀ depended on the association of each test with body size. When multiple correlations were obtained including surface area as the first variable, the only significant factor correlating with the endurance tests was the arm hang; none of the other tests showed a significant correlation. “Physical fitness” is task-specific, so that a subject''s position in the scoring scale of a fitness test depends entirely upon the test. The CAHPER test for physical fitness shows little or no correlation with standard laboratory measures of endurance in average children.     

Long-term effects of physical training programme on risk factors for coronary heart disease in otherwise sedentary men.

Three hundred and seventy sedentary men aged 20-65 years enrolled in a physical training programme after a medical and fitness examination that included measurements of "classical" risk factors for coronary heart disease. Five years later re-examination showed (a) that on average the subjects had not changed significantly in weight, blood pressure, serum lipid concentrations, smoking habits, and physical working capacity; (b) that men who had remained active and therefore had a higher degree of fitness did not differ in risk factors from men who had returned to sedentary habits; and (c) that men who had improved substantially in fitness did not differ in risk factors from men whose fitness had not changed or had declined. Five years after the initial programme one-third of the men were continuing with regular vigorous exercise. These results do not support the view that classical risk factors for coronary heart disease improve with increased physical activity and fitness.     

The Canadian Home Fitness Test as a predictor of aerobic capacity

The purpose of this study was to determine if maximum oxygen consumption (Vo₂ max) could be predicted from independent variables measured during the administration of the Canadian Home Fitness Test. Fifty-nine subjects between the ages of 15 and 74 years underwent the fitness test and a progressive exercise treadmill test for the direct determination of volitional Vo₂ max. The results indicated that Vo₂ max could be adequately predicted by the following regression equation: Vo₂ max (ml/kg·min) = 42.5 + 16.6(Vo₂) - 0.12(W) - 0.12(H) - 0.24(A), where Vo₂ is the average oxygen cost of the last completed exercise stage (in l/min), W is the body weight (in kg), H is the postexercise heart rate (in beats/min) and A is the age (in years).     

Canadian heart health surveys: a profile of cardiovascular risk. Survey methods and data analysis. Canadian Heart Health Surveys Research Group.

OBJECTIVE: To describe the methods used in nine provincial surveys carried out as part of the Canadian Heart Health Initiative. DESIGN: Population-based cross-sectional surveys, following a core standardized protocol, implemented by provincial departments of health in collaboration with Health and Welfare Canada. Data were obtained through a home interview and a clinic visit. A standard manual of field operations and standardized training procedures were used in all provinces. SETTING: Nine Canadian provinces during the period 1986 to 1990. PARTICIPANTS: A probability sample of 26,293 men and women aged 18 to 74 years was selected from the health insurance registries in each province. Over 30% of the participants had post-secondary education. About 50% were 18 to 34 years old. OUTCOME MEASURES: Data on sociodemographic characteristics, hypertensive and diabetic status, knowledge and awareness of the causes and consequences of cardiovascular disease and two blood pressure measurements were obtained in a home interview. During a clinic visit, data were collected on height, weight (waist and hip circumferences in four provinces), two blood pressure measures and a blood sample. Total plasma cholesterol, triglycerides and high- and low-density lipoprotein cholesterol were measured in the Lipid Research Laboratory, University of Toronto and St. Michael''s Hospital. MAIN RESULTS: Of the subjects invited to participate in the survey, 78% were interviewed, 69% attended the clinic and 64% provided a fasting specimen (8 hours or more). The response rates were slightly lower for men aged 18 to 34, for women aged 65 to 74 and for those with fewer years of education. Data from the provincial surveys (Ontario will complete the survey in 1992) are being compiled in the Canadian Heart Health Database. CONCLUSION: The process followed in the implementation of the provincial heart health surveys is a model of how provincial departments of health may carry out epidemiologic investigations in support of their mandate. The approach illustrates how a country-wide database can be built through partnerships among different levels of government. The use of community health nurses was instrumental in the efficient implementation of the surveys and in the realization of the relatively high rates of response attained.     

In situ autofluorescence detection of a fouling marine diatom on different surfaces

A new technique for quantifying fouling diatoms adhering to different surfaces was developed and tested. The method is based on recording the in vivo chlorophyll autofluorescence of diatom cells in situ. The enhanced signal obtained after addition of DCMU was used as a biomass estimate, and the enhancement itself as an indicator of the photosynthetic capacity. A fluorescence spectrometer equipped with a “well plate reader”; accessory was programmed to scan predetermined positions on the microscope slide based test surfaces. In standard tests, a matrix of 7 × 25 equidistant locations was applied to record the central 17 × 67 mm² area of the test surface. Thus, both spatial distributions and the mean value of chlorophyll associated with the specified area could be obtained directly. Microscopical counting was performed for calibration on transparent glass surfaces as well as PVA‐SbQ based hydrogels. There was a good correlation between counting and fluorescence recordings, with a linear range up to 1100 cells mm^?2. Due to the inherent inaccuracies of background estimates, the detection limit on glass and gel was approximately 200 cells mm^?2. The method was also applied successfully to test non‐transparent surfaces. In addition to standard mass screening of different test surfaces, the method may be found useful in studies of algal physiology related to cell adhesion, photosynthesis, growth, detachment and spatial migration.     

Effect of the Canadian Air Force training programme on a submaximal exercise test.

Validation of the submaximal heart rate/oxygen consumption relationship as an index of 'cardiorespiratory fitness' requires the demonstration of systematic alterations in this relationship concomitant with interventions designed to alter physical fitness. To fulfil those criteria a longitudinal training/de-training study was undertaken. Previously sedentary adult subjects undertook the Canadian Airforce 5BX-XBX exercise programme. Submaximal exercise tests were performed before and after training, and following several weeks cessation of training. A regression line of submaximal heart rate on submaximal oxygen consumption was calculated from the data of each submaximal exercise test. Alterations in the regression lines were examined for each subject individually by testing statistically for difference in slope and elevation between any pair of lines. Subjects who undertook the training/de-training study demonstrated significant systematic alterations in the elevation of the regression lines concomitant with periods of training and de-training. The reproducibility of the submaximal heart rate/oxygen consumption relationship was examined in two additional groups of subjects. Group A repeated a submaximal test on 3 or 4 successive days; Group B were tested before and after 16 weeks of normal activity. Subjects in Group A demonstrated non significant, random alterations in the regression lines on repeated testing and subjects in Group B demonstrated random, though on occasion significant, alterations in the regression lines. The elevation of the submaximal heart rate/oxygen consumption relationship is therefore a valid index for detecting sequential changes in 'cardiorespiratory fitness' in individual subjects.     

C reactive protein and its relation to cardiovascular risk factors: a population based cross sectional study.

OBJECTIVE--To test the hypothesis that minor chronic insults such as smoking, chronic bronchitis, and two persistent bacterial infections may be associated with increases in C reactive protein concentration within the normal range and that variations in the C reactive protein concentration in turn may be associated with levels of cardiovascular risk factors and chronic coronary heart disease. DESIGN--Population based cross sectional study. SETTING--General practices in Merton, Sutton, and Wandsworth. SUBJECTS--A random sample of 388 men aged 50-69 years from general practice registers. 612 men were invited to attend and 413 attended, of whom 25 non-white men were excluded. The first 303 of the remaining 388 men had full risk factor profiles determined. INTERVENTIONS--Measurements of serum C reactive protein concentrations by in house enzyme linked immunosorbent assay (ELISA); other determinations by standard methods. Coronary heart disease was sought by the Rose angina questionnaire and Minnesota coded electrocardiograms. MAIN OUTCOME MEASURES--Serum C reactive protein concentrations, cardiovascular risk factor levels, and the presence of coronary heart disease. RESULTS--Increasing age, smoking, symptoms of chronic bronchitis, Helicobacter pylori and Chlamydia pneumoniae infections, and body mass index were all associated with raised concentrations of C reactive protein. C Reactive protein concentration was associated with raised serum fibrinogen, sialic acid, total cholesterol, triglyceride, glucose, and apolipoprotein B values. C Reactive protein concentration was negatively associated with high density lipoprotein cholesterol concentration. There was a weaker positive relation with low density lipoprotein cholesterol concentration and no relation with apolipoprotein A I value. C Reactive protein concentration was also strongly associated with coronary heart disease. CONCLUSION--The body''s response to inflammation may play an important part in influencing the progression of atherosclerosis. The association of C reactive protein concentration with coronary heart disease needs testing in prospective studies.     

Does plasma cholesterol concentration predict mortality from coronary heart disease in elderly people? 18 year follow up in Whitehall study.

OBJECTIVE--To explore the extent to which the relation between plasma cholesterol concentration and risk of death from coronary heart disease in men persists into old age. DESIGN--18 year follow up of male Whitehall civil servants. Plasma cholesterol concentrations and other risk factors were determined at first examination in 1967-9 when they were aged 40-69. Death of men up to 31 January 1987 was recorded. SUBJECTS--18,296 male civil servants, 4155 of whom died during follow up. MAIN OUTCOME MEASURES--Cause and age of death. Cholesterol concentration in 1967-9 and number of years elapsed between testing and death. RESULTS--1676 men died of coronary heart disease. The mean cholesterol concentration in these men was 0.32 mmol/l higher than that in all other men (95% confidence interval 0.26 to 0.37 mmol/l). This difference in cholesterol concentrations fell 0.15 mmol/l with every 10 years'' increase in age at screening. The risk of raised cholesterol concentration fell with age at death. Compared with other men cholesterol concentration in those who died of coronary heart disease was 0.44 mmol/l higher in those who died aged less than 60 and 0.26 mmol/l higher in those aged 60-79 (p = 0.03). For a given age at death the longer the gap between cholesterol measurement and death the more predictive the cholesterol concentration, both for coronary heart disease and all cause mortality (trend test p = 0.06 and 0.03 respectively). CONCLUSION--Reducing plasma cholesterol concentrations in middle age may influence the risk of death from coronary heart disease in old age.     

Physiological monitoring of cardiorespiratory adaptations during rehearsal and performance of contemporary dance

Previous research has shown that dance class and rehearsal stress different cardiorespiratory energy systems than dance performance. The aim of the present study was to monitor the physiological parameters of a number of dancers during a 12-week rehearsal period and an 8-week performance schedule. Seventeen dancers (8 men and 9 women) from 2 companies undertook the multistage dance specific aerobic fitness test before the rehearsal period, before the performance period, and after the performance period. Heart rate data were collected throughout the test; the mean heart rate during stage 5 and blood lactate levels were measured at the end of the test. No significant changes in heart rate or lactate parameters were noted between the prerehearsal and preperformance tests, but significant decreases during the preperformance and postperformance tests were shown in both parameters (p < 0.01 and p < 0.01, respectively), which suggests an increase in the subjects' aerobic capacities during the performance period. Implications from the present study suggest that dancers are not adequately physiologically prepared to perform to the same degree to which their skills are honed. The study suggests that supplemental training is required to bridge this physical gap and better prepare the dancer for performance.     

Smoking prevalence and associated risk factors in Canadian adults. Canadian Heart Health Surveys Research Group.

OBJECTIVE: To describe the prevalence and patterns of smoking among Canadian adults, the relation of smoking to other cardiovascular disease risk factors and the awareness of the causes of heart disease. DESIGN: Population-based cross-sectional surveys. SETTING: Nine Canadian provinces, from 1986 to 1990. PARTICIPANTS: A probability sample of 26,293 men and women aged 18 to 74 was selected from the health insurance registries in each province. Of these, 20,585 completed a questionnaire on smoking habits during a home interview. MAIN RESULTS: Approximately 29% of the Canadian population 18 years of age and over were regular cigarette smokers, and over 13% of regular smokers smoked more than 25 cigarettes per day. The proportion of women who had never smoked was higher (37%) than men (24%), except for young women aged 18 to 24. For all participants, there was a lower prevalence of high blood pressure and overweight among smokers than non-smokers. The prevalence of sedentary lifestyle, diabetes and elevated blood cholesterol was positively associated with smoking. The proportion of subjects who identified smoking as a cause of heart disease was higher among smokers, and over 90% believe that heart disease is preventable. CONCLUSION: Because smoking is positively associated with other cardiovascular risk factors, multifactorial and comprehensive approaches are needed in the implementation of cardiovascular disease prevention programs. Knowledge regarding the heart health hazards of smoking is high even among smokers. Motivational approaches that go beyond health risk messages are needed in cessation programs.     

Frequency‐dependent fitness in gynodioecious Lobelia siphilitica

Selection is frequency dependent when an individual's fitness depends on the frequency of its phenotype. Frequency‐dependent selection should be common in gynodioecious plants, where individuals are female or hermaphroditic; if the fitness of females is limited by the availability of pollen to fertilize their ovules, then they should have higher fitness when rare than when common. To test whether the fitness of females is frequency dependent, we manipulated the sex ratio in arrays of gynodioecious Lobelia siphilitica. To test whether fitness was frequency dependent because of variation in pollen availability, we compared open‐pollinated and supplemental hand‐pollinated plants. Open‐pollinated females produced more seeds when they were rare than when they were common, as expected if fitness is negatively frequency dependent. However, hand‐pollinated females also produced more seeds when they were rare, indicating that variation in pollen availability was not the cause of frequency‐dependent fitness. Instead, fitness was frequency dependent because both hand‐ and open‐pollinated females opened more flowers when they were rare than when they were common. This plasticity in the rate of anthesis could cause fitness to be frequency dependent even when reproduction is not pollen limited, and thus expand the conditions under which frequency‐dependent selection operates in gynodioecious species.     

Physiological adaptation in noncompetitive rock climbers: good for aerobic fitness?

The present investigation aimed to establish whether noncompetitive rock climbing fulfills sports medicine recommendations for maintaining a good level of aerobic fitness. The physiological profile of 13 rock climbers, 8 men (age, 43 +/- 8 years) and 5 women (age, 31 +/- 8 years) was assessed by means of laboratory tests. Maximal aerobic power (VO2peak) and ventilatory threshold (VT) were assessed using a cycloergometer incremental test. During outdoor rock face climbing, VO2 and heart rate (HR) were measured with a portable metabolimeter and the relative steady-state values (VO2 and HR during rock climbing) were computed. Blood lactate was measured during recovery. All data are presented as mean +/- SD. VO2 was 39.1 +/- 4.3 mL.kg.min in men and 39.7 +/- 5 mL.kg.min in women, while VT was 29.4 +/- 3.0 mL.kg.min in men and 28.8 +/- 4.6 mL.kg.min in women. The VO2 during rock climbing was 28.3 +/- 1.5 mL.kg.min in men and 27.5 +/- 3.7 mL.kg.min in women. The HR during rock climbing was 144 +/- 16 b.min in men and 164 +/- 13 b.min in women. The aerobic profile was classified from excellent to superior in accordance with the standards of the American College of Sports Medicine (ACSM). The exercise intensity (VO2 during rock climbing expressed as a percentage of VO2peak) was 70 +/- 6% in men and 72 +/- 8% in women. Moreover, the energy expenditure was 1000-1500 kcal per week. In conclusion, noncompetitive rock climbing has proved to be a typical aerobic activity. The intensity of exercise is comparable to that recommended by the American College of Sports Medicine to maintain good cardiorespiratory fitness.     

Present views on the Canadian Home Fitness Test.

The Canadian Home Fitness Test was conceived for the mass testing of fitness levels and as a motivational tool in exercise programs. A double step (such as in a domestic staircase) is climbed at an age- and sex-specific rhythm set by a long-playing record. Fitness is assessed from test duration and the radial or carotid pulse count immediately following exercise. To date, use of the procedure by almost 500,000 Canadians has given rise to no serious complications. The test inevitably has limited precision when taken at home, although most subjects can learn to count their pulse and to step in time with the music. The test has been well received and has achieved its prime objective of stimulating an interest in endurance activity. When supervised by a paramedical worker using an electrocardiograph to monitor the heart rate during exercise, the procedure yields as good an estimate of maximum oxygen intake as other submaximal tests. One current area of controversy is the interpretation of abnormal electrocardiograms. It is suggested that this problem could be resolved by the appropriate training and certification of interested family physicians and paramedical workers.     

A 6-month supervised employer-based minimal exercise program for police officers improves fitness

The purpose of the study was to determine the effects of a 6-month supervised, job-specific moderate exercise program in police officers on body composition, cardiovascular and muscular fitness. Body weight (BW), body mass index (BMI), and cardiovascular and muscular fitness were assessed at baseline, after a 6-month supervised fitness program and at 12-month follow-up (18 months). One hundred sixty-five (n = 131 men and n = 34 women) young (mean ± SEM, 26.4 ± 1.9 years), overweight (BMI = 26.2 ± 1.2 kg·m) police officers participated. Aerobic exercise progressed from 3 d·wk, 20 minutes per session at 60% of the heart rate reserve (HRR) to 5 d·wk, 30 minutes per session at 75% of HRR at 3 months, and this level was maintained until 6 months. Muscular strength training progressed using 8 different calisthenics exercises from 3 d·wk, 2 sets of 5 repetitions using the participant's own BW to 5 d·wk, 3 sets of 15 repetitions of the participant's own BW at 3 months, and this level was maintained until 6 months. Cardiovascular and muscular fitness was measured using a 0.25-mile obstacle course incorporating various job-specific exercises and expressed as the physical abilities test (PAT) time. There was a significant reduction in BMI (-0.6 ± 0.2 kg·m, p < 0.001) and BW (-2.8 ± 2.3 kg) and reduction in PAT time (-11.9 ± 2.1%, p < 0.01) from baseline to 6 months. However, BMI (1.4 ± 1.1 kg·m, p < 0.001), BW (5.1 ± 3.0 kg, p < 0.01), and PAT time significantly increased (12.8 ± 2.2%, p < 0.01) from 6 to 18 months. There were no sex by time differences. The practical applications of this study indicate that a supervised, job-specific exercise program for police officers improves fitness and body composition after 6 months in both men and women, but continued supervision of exercise program may be necessary for maintenance of health benefits.     

Type A behaviour and ischaemic heart disease in middle aged British men.

The Bortner questionnaire, which measures aspects of type A (coronary prone) behaviour was completed by 5936 men aged 40-59 selected at random from one general practice in each of 19 British towns. The presence of ischaemic heart disease was determined at initial examination and the men were followed up for an average of 6.2 years for morbidity and mortality from myocardial infarction and for sudden cardiac death. Non-manual workers had significantly higher scores (more type A) than manual workers and the score decreased (less type A) with increasing age. After adjustment for social class and age men with higher scores had higher prevalences of ischaemic heart disease less marked for electrocardiographic evidence and more marked for response to a chest pain questionnaire (angina or possible myocardial infarction). A man''s recall of a doctor''s diagnosis of ischaemic heart disease, however, did not relate to his Bortner score. There was no significant relation between the Bortner score and the attack rate or incidence of major ischaemic heart disease events. In this study type A behaviour, as measured by the Bortner questionnaire, did not predict major ischaemic heart disease events in British middle aged men.     

Human ACE I/D polymorphism is associated with individual differences in exercise heat tolerance.

We hypothesized that there is an association between the angiotensin I-converting enzyme (ACE) insertion (I)/deletion (D) polymorphism with the variability in exercise heat tolerance in humans. Fifty-eight Caucasian men were exposed to a 2-h exercise heat-tolerance test. We analyzed the association between their heat-tolerance levels with the ACE DD (n = 25) and I+ (n = 33) genotypes and with various anthropometrical parameters and aerobic fitness. It was found that the relative changes in body core temperature, heat storage, and heart rate during the 120-min exposure to exercise heat stress was consistently lower in the I+ genotype group compared with the DD genotype group (0.8 +/- 0.2 vs. 1 +/- 0.1 degrees C, P < 0.05; 17.7 +/- 1.8 vs. 19.8 +/- 1.3 W/M(2), P < 0.05; and 33 +/- 7 vs. 44 +/- 5 beats/min, respectively, P = 0.06). No significant association was found between heat strain response and the anthropometrical measurements or aerobic fitness in the various genotype groups. We suggest that the ACE I+ polymorphism may be considered as a possible candidate marker for increased heat tolerance.