Showing papers by "Claude Bouchard published in 1985"

Evidence for a regional component of body fatness in the association with serum lipids in men and women

Abstract: Four hundred and seventy-two subjects (234 women and 238 men), 18 to 50 years of age, participated in percent body fat determination from underwater weighing, assessment of 6 subcutaneous skinfold thicknesses, and a 12-hour fast blood sampling for measurement of serum triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), total cholesterol (CHOL), and HDL-C/CHOL ratio Even though women were significantly fatter than men, they had lower TG, CHOL, and higher values of HDL-C/CHOL ratio Correlational and variance analyses showed that body fatness seemed to be more closely associated with serum lipids in men than in women Moreover, the relationship between each skinfold and serum lipids indicated that subscapular and abdominal fat depots are more closely associated with serum lipids than other fat depots in men In women, correlations were lower and regional differences attenuated Furthermore, the regional trend observed in men remained significant after correction for concomitant variables such as age, cigarette smoking, habitual energy intake and energy expenditure, maximal aerobic power, and alcohol consumption However, no effect of increasing body fatness was noted on HDL-C levels in women Results of this study suggest that measurement of subscapular and abdominal fat should be considered when interpreting the blood lipid profile, particularly in males A higher percentage of fat must be present in women than in men to observe alterations in serum lipids

Skeletal muscle histochemical and biochemical characteristics in sedentary male and female subjects.

Abstract: The purpose of this study was to assess the relationship between muscle fiber type distribution and enzymatic characteristics in sedentary male and female subjects. Muscle biopsy samples from the vastus lateralis muscle of 38 females and 37 males were analyzed to determine the fiber type composition (I, IIa, and IIb), the fiber size, and maximal activities of enzyme markers of energy metabolic pathways. Significant correlations were found (p < 0.05) between percent fiber type I area and hexokinase (r = −0.39), phosphofructokinase (r = −0.39), lactate dehydrogenase (r = −0.41), and oxoglutarate dehydrogenase (r = 0.33) activities, whereas such correlations with total phosphorylase (r = −0.02), malate dehydrogenase (r = 0.12), and 3-hydroxyacyl CoA dehydrogenase (r = 0.12) activities were not significant. The results of the present study also suggest the presence of a significant but low covariation of less than 30% between the fiber type distribution and muscle enzyme activities. They confirm the presence ...

Human skeletal muscle fiber type alteration with high-intensity intermittent training

Abstract: The response of muscle fiber type proportions and fiber areas to 15 weeks of strenuous high-intensity intermittent training was investigated in twenty-four carefully ascertained sedentary (14 women and 10 men) and 10 control (4 women and 6 men) subjects. The supervised training program consisted mainly of series of supramaximal exercise lasting 15 s to 90 s on a cycle ergometer. Proportions of muscle fiber type and areas of the fibers were determined from a biopsy of the vastus lateralis before and after the training program. No significant change was observed for any of the histochemical charactertics in the control group. Training significantly increased the proportion of type I and decreased type IIb fibers, the proportion of type IIa remained unchanged. Areas of type I and IIb fibers increased significantly with training. These results suggest that high-intensity intermittent training in humans may alter the proportion of type I and the area of type I and IIb fibers and in consequence that fiber type composition in human vastus lateralis muscle is not determined solely by genetic factors.

Body composition in adopted and biological siblings.

Abstract: Body density through underwater weighing and 6 skinfolds (triceps, biceps, subscapular, suprailiac, abdominal and medial calf) were measured in 871 biological and adopted siblings of French descent from the greater Quebec city area. These individuals belonged to 49 sibships of adopted sibs, 71 sibships of unrelated individuals living together including adoptees, 35 «sibships» of first degree cousins, 229 sibships of biological brothers and sisters, 66 sibships of DZ twins and 83 sibships of MZ twins. Age of subjects ranged from 8 to 26 years. Age and sex accounted from 14% to 48% of the variance in body composition measurements, with the exception of fat free weight (71%). Residual scores of age and sex were submitted to analysis of variance and correlation analysis. The ratio of the between sibships to the within sibship means of squares reached significance (p ^ .05) for almost all measurements in the MZ, DZ, biological and cousin sibships, for the skinfolds but not for body density, fat free weight and the ratio of subcutaneous fat to total fat mass in the unrelated sibships, and for none of the measurements in the adoptive sibships. Interclass correlations could be computed in a maximum of 80 pairs of adopted sibs, 120 pairs of unrelated sibs, 95 pairs of cousins, 370 pairs of biological sibs, 69 pairs of DZ twins and 87 pairs of MZ twins. None of the coefficients reached 0.20 (p < 0.05) in the pairs of adopted or unrelated sibs. On the other hand, correlations were often significant in the pairs of cousins, particularly for the skinfold measurements. The same coefficients were generally significant and increasing from the pairs of brothers and sisters to the pairs of DZ twins and MZ twins. This pattern was particularly clear for several individual skinfolds, the extremity and the trunk skinfolds, the ratio of extremity to trunk subcutaneous fat and fat free weight. Genetic effects reaching about 0.40 and above were found for measurements of subcutaneous fat, fat distribution, body density and fat free weight. Twin data yielded higher and often unrealistic estimates of heritability probably because of the differential effects of the common environment in MZ and DZ pairs. Skinfold measurements, body density obtained through underwater weighing and fat free mass derived from the latter are generally used as indicators of body composition in humans (Malina, 1980). Several investigators have studied skinfold measurements in biologically related brothers and sisters (Howells, 1966; Garn et al. 1975; Mueller, 1978; Mueller and Malina, 1980; Bouchard, 1980; Savard et al. 1983). Others have considered skinfold data in pairs of dizygotic and monozygotic twins living 1Physical Activity Sciences Laboratory, Laval University, Quebec, Canada G1K 7P4. Human Biology, February 1985, Vol. 57, No. 1, pp. 61-75 © Wayne State University Press, 1985 This content downloaded from 157.55.39.144 on Wed, 07 Sep 2016 04:31:57 UTC All use subject to http://about.jstor.org/terms 62 Claude Bouchard et al. together (Osborne and DeGeorge, 1959; Brook et al. 1975; Hawk and Brook, 1979), but only Garn and co-workers (1979) have reported such data in pairs of genetically unrelated siblings living together. On the other hand, the studies cited above have used a maximum of four skinfold measurements, with the exception of Savard et al. (1983), who reported on six sites. Moreover, the relationship between subcutaneous fat and total body fat is not a simple one, as it is affected by age, sex and total fat among several factors (Lohman, 1981). To the best of our knowledge, no studies have been published about body density and fat free weight in biological and unrelated siblings. Therefore, the purpose of this report is to analyse the resemblance in unrelated and biological sibships and the covariation in pairs of sibs of various kinds for six skinfold measurements, subcutaneous fat distribution, body density, fat free weight and a ratio of subcutaneous fat to total fat mass. Material and Methods

Familial resemblance in maximal heart rate, blood lactate and aerobic power.

Abstract: There are considerable interindividual differences in maximal oxygen uptake per kilogram of body weight (VO2 max/kg), maximal heart rate (max HR) and maximal blood lactate (max blood La) measured during a progressive exercise test. The aim of the study was to quantify the familial relationships for these variables. Parents and children of 38 families of French-Canadian descent were submitted to a modified Balke treadmill test. VO2 max/kg and max HR were the highest values reached during the test for 1 min. Max blood La was obtained from a blood sample taken 2 min after the test. The effects of age and sex were significant for max blood La and VO2 max/kg in each generation. Scores were thus adjusted through multiple regression procedures (age + sex + age X sex + age2), yielding residuals which were submitted to further analysis. Intraclass correlations (ri) were significant in pairs of sibs for max blood La and max HR, i.e. 0.28 (p less than 0.01) and 0.43 (p less than 0.05), respectively. For VO2 max/kg, pairs of spouses and sibs were about similarly correlated (ri = 0.20 and 0.15; p less than 0.05). Data suggested that children were more related to their mother than to their father for VO2 max/kg, VO2 max/kg of fat-free weight, and particularly for max HR. It was concluded that familial resemblance and heritability estimates for maximal aerobic power, max HR and max blood La were quite low and generally nonsignificant. Correlations between biological sibs were, however, consistently significant for max HR and max blood La. The suggestion of a maternal effect in maximal aerobic power should be further investigated.

The effects of exercise-training on energy balance and adipose tissue morphology and metabolism.

Abstract: The effects of exercise training on energy expenditure, energy intake, fat cell size and adipose tissue lipolysis have been reviewed. Individuals engaged in regular and intense training programmes, e.g. long distance runners, seem to exhibit an elevated resting metabolic rate but moderate training is not accompanied by any important change. Diet-induced thermogenesis is a significant component of daily energy expenditure. It is still unclear whether or not exercise or training causes significant alteration in the thermic response to food intake. Energy expenditure associated with physical activity can play a meaningful role in body composition and adipose tissue metabolism. Largest weight losses have been achieved with programmes of long duration, presumably without marked compensation in food intake. However, it has been shown repeatedly that an increase in energy expenditure with exercise training tends to be associated with an elevation in food intake in free-living individuals. Weight loss is concomitant with a reduction in fat cell diameter and, when caused by an exercise training programme, it is generally accompanied by an increase in fat cell lipolytic activities. There are clear indications that weight loss induced by exercise training has a much higher fat content than weight loss caused by dieting. In addition, data suggest that exercise training may result in a greater depletion of fat stores than a low calorie diet, thus delaying the advent of the resistance phase to fat loss. Data on human subjects derived from well controlled energy balance and metabolic experiments are needed to further advance our understanding about the effects of exercise training on the adipose tissue.

Do the new Metropolitan Life Insurance weight-height tables correctly assess body frame and body fat relationships?

Abstract: The 1983 Metropolitan weight-height tables include elbow breadth as a measure of frame size. Such tables assume that frame measures provide an estimate of fat free mass and have little or no associations with body fat. These assumptions were evaluated in 437 Canadian adults for six frame measures by their associations with total body measures of fat and fat free mass. All six frame measures were similarly correlated with fat free mass, even when associations with height were taken into account. Wrist and ankle breadths were not associated with total body fat, while shoulder, elbow, hip, and knee breadths were so associated. Thus wrist and ankle breadths satisfy the assumptions inherent in the frame-weight-height tables better than elbow breadth and the other frame measures investigated.

Resting metabolic rate in monozygotic and dizygotic twins.

Abstract: In order to study the influence of heredity on resting metabolic rate (RMR), 20 monozygotic and 19 dizygotic male twins pairs aged 20.6 (SD 2.9) and 21.4 (SD 3.1) years, gave their consent to participate in the experiment. Fat free weight (FFW) was estimated from underwater weighing. RMR was measured by indirect calorimetry using an open circuit system. RMR was expressed as kJ X min-1, kJ/m2 X h-1, kJ/kg X h-1 and kJ/kgFFW X h-1. Significant intraclass coefficients were observed in MZ twins for the different expressions of RMR. The values ranged from r = 0.45 (P less than 0.05) to r = 0.81 (P less than 0.01). However, DZ twins demonstrated lower intraclass coefficients for RMR, with a range from r = 0.21 to r = 0.44. Significant (P less than 0.05) DZ resemblance was revealed only when RMR was expressed as kJ X min-1 and kJ/kg X h-1. Results of the present study suggest that variations in RMR may have a genetic component. Implications for human energy balance and body fat are discussed.

Influence of caffeine on the resting metabolic rate of exercise-trained and inactive subjects.

Abstract: The effect of caffeine on the resting metabolic rate (RMR) was investigated in endurance exercise-trained (N = 14) and inactive (N = 10) male individuals. Subjects were also classified into regular and non-regular consumers of caffeine. After an overnight fast, RMR was measured using an indirect calorimetry open circuit system. Thereafter, subjects orally consumed 300 mg of caffeine, after which RMR was measured for 90 min. Five of the exercise-trained subjects were also studied after the administration of a placebo. Plasma concentrations of glycerol and free fatty acid and respiratory exchange ratio (R) were measured at each 15-min interval. Before caffeine ingestion, no significant differences were observed in RMR, R, glycerol, free fatty acid and blood pressure levels between exercise-trained and inactive groups. Following caffeine consumption, a three-way analysis of variance revealed that inactive subjects exhibited a greater increase (P less than 0.05) in RMR than did exercise-trained subjects. No significant differences were observed in RMR response between regular or nonregular consumers of caffeine. Moreover, no differences were observed in glycerol, free fatty acid, heart rate, and blood pressure response between exercise-trained and inactive subjects and between regular and non-regular consumers of caffeine. These results suggest that endurance training results in a reduced thermogenic response to a caffeine challenge.

Effects of aerobic training on fat distribution in male subjects.

Abstract: To investigate the effects of aerobic training on adipose tissue morphology and fat distribution, several indicators of body fatness (percent body fat, seven subcutaneous skinfolds, fat cell weight) were assessed in 13 sedentary male subjects (SS) submitted to a 20-wk aerobic training program and in 20 male long-distance runners (LDR). The LDR subjects had a mean +/- SD VO2max of 65.9 +/- 6.5 ml . min-1 . kg-1 and averaged 120 km . wk-1. Training increased the VO2max values of the SS group significantly (pre: 41.9 +/- 7.0 vs post: 53.4 +/- 6.4 ml . kg-1 . min-1; P less than 0.001) and decreased significantly percent body fat (P less than 0.01), sum of skinfolds (P less than 0.01), and fat cell weight (P less than 0.05). Trunk skinfolds were more altered by training than extremity skinfolds, with reductions of 22 and 12.5%, respectively. Significant correlations were found between fat cell weight and percent body fat in SS before and after training (r = 0.75; P less than 0.01), while no significant relationship was noted in the LDR group. Moreover, using the sum of skinfolds divided by percent fat or by fat mass to reflect the proportion of subcutaneous fat to total fat, the LDR subjects exhibited less subcutaneous fat than the SS group (P less than 0.01) and training did not alter these ratios in the SS group. These results suggest that 20 wk of aerobic training can alter body fatness in men but that the induced fat loss does not seem to deplete preferentially subcutaneous fat.

Cardiac Dimension Changes With Endurance Training: Indications of a Genotype Dependency

Abstract: We studied the sensitivity of cardiac structures to endurance training. To evaluate variability in adaptation, 20 sedentary subjects and ten pairs of monozygotic twins were submitted to a 20-week endurance training program. Maximal oxygen uptake increased significantly in both groups: 11 mL O 2 /kg/min -1 or 30% in the sedentary group and 6 mL O 2 /kg/min -1 or 13% in the monozygotic twins. Statistically significant increases in left ventricular diameter, posterior wall and septal thicknesses, as well as left ventricular end-diastolic volume and left ventricular mass were observed in the sedentary subjects, but not in the monozygotic twins. We could demonstrate that after training, twin pairs differed more from each other than at the start. Concomitantly, within-pair resemblance was greater after training than before. Results indicate that cardiac dimensions are amenable to significant modifications under controlled endurance training conditions and furthermore that the extent and variability of the response of cardiac structures to training are perhaps genotype dependent. ( JAMA 1985;254:77-80)

Relationships between skeletal muscle characteristics and aerobic performance in sedentary and active subjects.

Abstract: Forty-eight sedentary and 39 quite active or well-trained men participated in this study. Muscle biopsy samples were taken from the vastus lateralis for the determination of fiber type composition (I, IIa, IIb), fiber type area, and assay of the following enzymes: malate dehydrogenase (MDH), 3-hydroxyacyl CoA dehydrogenase (HADH) and oxoglutarate dehydrogenase (OGDH). Maximal oxygen uptake ( $$\dot V_{{\text{O}}_{{\text{2max}}} }$$ ) was determined with a progressive cycle ergometer test, while endurance performance or maximal aerobic capacity (MAC) was defined as the total work output during a 90-min cycle ergometer test. Correlation analysis revealed no evidence of association between fiber type composition and $$\dot V_{{\text{O}}_{{\text{2max}}} }$$ kg−1 or MAC kg−1 in sedentary subjects, while active men exhibited significant correlation between % type I (r=0.52), % type IIb (r=−0.31) and $$\dot V_{{\text{O}}_{{\text{2max}}} }$$ kg−1. Enzyme activities were not significantly correlated with MAC kg−1 and $$\dot V_{{\text{O}}_{{\text{2max}}} }$$ kg−1 in sedentary men while active men exhibited significant correlation for the three enzymes (0.37≤r≤0.51) with $$\dot V_{{\text{O}}_{{\text{2max}}} }$$ kg−1. These results show that the contribution of muscle fiber type and enzyme activities to aerobic performance may be inflated from a statistiscal point of view by the training status heterogeneity of subjects. They also suggest that variation in these muscle characteristics does not account for the individual differences in aerobic performance of subjects who have never trained before. Therefore, the assessment of muscle characteristics is not as useful as originally thought for the detection of individuals with a high potential for endurance performance among untrained subjects.

Endurance training and glucose conversion into triglycerides in human fat cells

Abstract: To study the influence of endurance training on glucose conversion into fat cell triglycerides, 24 (13 women, 11 men) inactive subjects (25.0 +/- 3.8 yr of age) took part in a 20-wk ergocycle training program 4 days and increasing to 5 days/wk, 40–45 min/day, starting at 60% and increasing to 85% of the heart rate reserve. Several body fatness indicators were measured before and after the training program: seven skinfold thicknesses, percent fat, and mean fat cell weight. Fat cell basal and maximal insulin-stimulated glucose conversion into triglycerides were also determined using [14C]glucose. Body fatness indicators decreased significantly after training only in male subjects (P less than 0.05). Basal and maximal insulin-stimulated glucose conversion into triglycerides increased significantly with training (P less than 0.05): pretest values (nanomoles glucose per hour per 10(6) cells) being 24.9 +/- 2.1 and 28.7 +/- 2.5, while post-test values were 30.1 +/- 3.2 and 33.0 +/- 3.4 for basal and insulin-stimulated values, respectively. However, this lipogenic increase was only observed in male subjects (P less than 0.01). Changes in body fatness indicators induced by training were negatively correlated with changes induced in fat cell glucose conversion into triglycerides (-0.24 less than or equal to r less than or equal to -0.45). These results demonstrate that endurance training increases fat cell glucose conversion into triglycerides and suggest that adipose tissue metabolism is part of the adaptive response to training. Moreover, it appears that adipose tissue response to aerobic training is more efficient in males than in females.

Specificity of aerobic and anaerobic work capacities and powers.

Abstract: Thirty-three untrained subjects of both sexes, 18-31 years of age, performed several tests on cycle ergometers. Maximal aerobic power (MAP) was obtained in a progressive work test. Maximal aerobic capacity (MAC) was measured in a 90-min maximal test and was computed as the total work output during that period. Two all-out cycle ergometer work tests lasting 10 s and 90 s were used to estimate the anaerobic alactic capacity (AAC) and lactic capacity (ALC). Anaerobic alactic power (AAP) was computed as the highest output in 1 s in the AAC test and anaerobic lactic power (ALP) was obtained as the mean output during the last 5 s in an all-out test of 30 s. Correlation coefficients were computed between all measurements of capacity and power expressed per kg of body weight as well as with scores adjusted for sex differences. Common variances (r2 X 100) between measurements of power were either low (MAP-AAP, 40%) or moderate (MAP-ALP, 61%; AAP-ALP, 62%) while common variances between measurements of capacity were sometimes low (MAC-AAC, 49%) or higher (MAC-ALC, 76%; AAC-ALC, 77%). The common variances between tests of power and capacity reached high values when calculated with metabolic criteria of the same class (MAP-MAC, 81%; AAP-AAC, 92%). These results provide quantitative evidence to support the notion of specificity between the aerobic and the anaerobic work performances and support the distinction between capacity and power of the three energy systems.

Adipose tissue lipid accumulation pathways in marathon runners.

Abstract: Eighteen male marathon runners (mean marathon performance: 2 h 36 min, SD = 7.0 min; VO2 max = 64.1 +/- 15.1 ml/kg . min-1) were submitted to a needle biopsy in the suprailiac region and to various measurements of body fatness: percent body fat (% fat), seven skinfold thicknesses, and mean fat cell diameter. Basal and insulin-stimulated glucose conversion into triglycerides were measured in collagenase-isolated fat cells, while heparin-releasable lipoprotein lipase activity (LPLa) was determined in intact adipose tissue. All body fatness indicators were significantly smaller in marathon runners in comparison to a sedentary control group (P less than 0.001). Fat cell basal and insulin-stimulated glucose conversion into triglycerides as well as LPLa were significantly higher for the runners group (P less than 0.01), differences being particularly important when comparisons were performed between subjects paired for mean fat cell diameter. Pearson interclass correlations between body fatness and fat cell glucose incorporation into triglycerides were low and positive for the sedentary group (0.04 less than or equal to r less than or equal to 0.41), while they were negative for the marathon runners groups (-0.28 less than or equal to r less than or equal to -0.40) with the exception of % fat. Moreover, correlations between LPLa and indicators of body fatness were positive in the sedentary group (0.47 less than or equal to r less than or equal to 0.79), while they were negative in the marathon runners group (-0.03 less than or equal to r less than or equal to -0.63).(ABSTRACT TRUNCATED AT 250 WORDS)

HLA system, body fat and fat distribution in children and adults.

Abstract: The association between the genotypes and the alleles at the A, B or C locus of the HLA system and body fat was studied in a total of 1578 individuals subdivided in four cohorts: adult males (n greater than or equal to 204), adult females (n greater than or equal to 184), boys and male adolescents (n greater than or equal to 282), and girls and female adolescents (n greater than or equal to 257) None of these subjects were grossly obese or had known metabolic disorders Percent body fat from underwater weighing, subcutaneous fat from 6 skinfold measurements, trunk fat (3 skinfolds) and extremity fat (3 skinfolds) were considered in the analysis Although a few significant associations were encountered, the lack of consistency across samples suggested that they were probably random and biologically not meaningful The same negative findings were found for the ratio of trunk subcutaneous fat to extremity subcutaneous fat and the ratio of subcutaneous fat (6 skinfolds) to total fat mass Earlier reports indicating a significant association between high body fat content and antigens B18, Bw35 or Cw4 were not supported by the results of this study It was concluded that no consistent pattern of association emerged between genotypes or alleles of the HLA system and percent body fat, subcutaneous fat or fat distribution in children and adults of both sexes