Search PubMed⌕ Search

Biomedical subjects

C Bouchard

Publications and source records attributed to C Bouchard.

At least 613 records · Page 34Linked to original sources
PubMed1980

Heritability estimates of somatotype components based upon familial data.

Somatotype components were obtained in 239 French-Canadian families from Montreal. Endomorphy, mesomorphy and ectomorphy were anthropometrically assessed in the Health and Carter system. All three components were available in 208 pairs of siblings, while only ectomorphy was estimated in 507 parent-child pairs. Sibling correlations reached 0.40 for endomorphy, 0.30 for mesomorphy, and 0.38 for ectomorphy. Partialling out the effects of 7 socioeconomic indicators permitted an estimate of common familial environment upon covariation between relatives. Residual sibling correlations yielded broad heritability estimates (HB) of 0.50 for endomorphy, 0.42 for mesomorphy and 0.54 for ectomorphy. Narrow heritability (HN) for ectomorphy, controlling for familial indicators, was approximately 0.36 including a positive contribution from assortative mating.

Adult↗
PubMed1979

Specificity of maximal aerobic power.

Several types of work tasks are used to assess maximal aerobic power (MAP) in humans. Although it is well established that these work tasks may yield different absolute MAP values, little is known about the extent of the specificity of each MAP work task. 30 moderately active young men were tested at random for MAP with five commonly used work tasks: cycling supine, cycling sitting, alternate arm cranking standing, walking on a treadmill, and stepping on a bench. Statistical analyses show that these five tests do not give equal MAP means, equal variances or equal covariances. Various correlation techniques indicate, furthermore, that the common variance between the five aerobic power measurements is at best moderate. It was estimated that the overall common variance for Max ml O2 . kg-1 . min-1 reached about 50% of the total variance. The most efficient linear loading of each test in the first principal component could account only for 75% of the observed variance in MAP. It is concluded that these five work tasks do not yield parallel test forms, that the practice of transforming one MAP value into another should be abandoned, and that the practice of generalizing from one MAP value to a theoretical general MAP of the human body is not justified.

Adult↗
PubMed1979

Age at menarche, family size, and birth order in athletes at the Montreal Olympic Games, 1976.

Age at menarache, family size, and birth order in 145 athletes at the Montreal Olympic Games, 1976, were determined through interview. The athletes represented 27 countries, but 76% came from Canada, Great Britain and the United States. On the average, athletes attained menarche later than the general population in their respective countries, the mean age at menarche for the sample of 139 athletes who had attained menarche at the time of the survey being 13.66 +/- 0.12 years. Six athletes had not yet attained menarche at the time of the survey. Gymnasts, runners and rowers attained menarche significantly later than swimmers, but gymnasts, runners, rowers and jumpers/hurdlers did not differ significantly among themselves in the age at menarche. Correlations between age at menarche and family size and birth order were significant, but low to moderate in magnitude. Athletes from larger families tended to have, on the average, later menarche than those from smaller families, this trend being more apparent in rowers and track and field athletes.

Adolescent↗
PubMed1978

Skeletal age and submaximal working capacity in boys.

Skeletal age (SA) and Vo2 at a heart rate of 130 (Vo130) during work on a bicycle ergometer were measured in 237 boys 8-18 years of age. Analysis indicates that Vo130 is well correlated with SA, but also is equally well correlated with chronological age (CA), height and body weight. Age-specific correlations show that Vo130 is associated with SA from 12 through 16 years of age. Partialing out SA results in a significant decrease in the correlations of either height or weight with Vo130 only in the 12-16 year subgroup. The total common variance explained in Vo130 when regressed over CA, height and weight is affected by the presence of SA only in the 12-16 age subset. In spite of the high degree of multicollinearity among the independent variates, correlation data seem to indicate that SA and Vo130 have a slightly higher degree of relationship circumpuberally, i.e. between 12 and 16 years of age.

Adolescent↗
PubMed1977

Submaximal working capacity, heart size and body size in boys 8-18 years.

Heart diameters, heart volume (HV), PWC130, VO2 at 130 heart rate, and cardiorespiratory reactions during work at 3 kgm-s-1 were obtained in 237 boys ranging in age from 8--18 years. Results indicate that heart size, PWC130, VO130, and exercise HR, VO2/HR, f and SBP change significantly with age. On the other hand, HV - kg-1 and work VO2, VE and VE/VO2 remain rather stable throughout the growth period. Correlation analysis indicates that about 85% of the observed variation in the size of the heart during growth can be accounted for by the body weight, while about 70% of the variation in light submaximal working capacity (VO130) can be explained by HV alone. Holding age, height and body weight constant by partial correlation procedures yeilds significant relationships between HV and VO130 (r = 0.461), and between HV - kg-1 and VO130 (r = 0.414). Age, height, weight and size of the heart correlated simultaneously against VO130 account for 75% of the variance in the dependent variable. It would seem important to suggest the need for study of the interactions between age, size and maturity, in addition to indicators of size and efficiency of the oxygen delivery system, and indices of muscle oxygen utilization efficiency. Such an approach will permit a more definite partitioning of the variance in submaximal aerobic capicity during growth, and would probably yeild a more conservative estimate of the relationship between the size of the heart and submaximal working capacity during growth.

Adolescent↗
PubMed1976

[Sympathectomy].

Explore the source record for details and available documents.

Humans↗
PubMed1976

Relationships between skeletal maturity and submaximal working capacity in boys 8 to 18 years.

Skeletal age (SA) height, weight, PWC130, Vo2 at 130 heart rate (Vo130) and cardiorespiratory adaptation to work at 3 kgm-sec-1 were measured in 237 boys ranging in age from 8 to 18 years. Correlations for the total population for the variables of the study are generally higher with SA than with chronological age (CA), although there is no significant difference between the two sets of correlations. Analysis of linear trend indicate that significant nonlinear components are more frequent in the relationships between the variables and SA than with CA.Multiple regression analyses for each variate as dependent variable indicate that height and body weight generally contribute more to the explained variance, while SA is the next best predictor. CA is the least significant of the four independent variables. The total variance explained between any of the submaximal working capacity related measures acting as dependent variable and CA, height and weight is not significantly affected by the presence or absence of SA. The present study thus indicates that SA is not a significant factor in explaining submaximal working capacity, beyond CA, height and weight, when considered over the 8 to 18 year age span. However, when considering shorter age spans, or when considering the adolescent period (12-16 years), SA correlates better with PWC130 (.320 less than r less than .675) and with Vo130 (.299 less than r less than .772).

Adolescent↗