This study investigates the familial resemblance of maximal oxygen uptake(˙VO2max) based on data from 86 nuclear families of Caucasian descent participating in the HERITAGE Family Study. In the current study,˙VO2max was measured twice on a cycle ergometer in 429 sedentary individuals (170 parents and 259 of their offspring), aged between 16 and 65 yr. The ˙VO2max was adjusted by regression procedures for the effects of 1) age and sex; 2) age, sex, and body mass; and 3) age, sex, body mass, fat mass, and fat-free mass, as determined by underwater weighing. Evidence for significant familial resemblance was observed for each of the three ˙VO2max phenotypes. Spouse, sibling, and parent-offspring correlations were significant, suggesting that both genetic and environmental factors contribute to the familial resemblance for ˙VO2max. Maximal heritability estimates were at least 50%, a value inflated to an undetermined degree by nongenetic factors. The hypothesis of maternal inheritance, with the father's contribution being environmental, was also found to fit the data with estimates of maternal heritability, potentially associated in part with mitochondrial inheritance, reaching about 30%. These results suggest that genetic and nongenetic factors as well as maternal influences contribute to the familial aggregation of ˙VO2max in sedentary individuals.
Physical Activity Sciences Laboratory, Laval University, Québec, G1K 7P4, CANADA; School of Kinesiology and Leisure Studies, University of Minnesota, Minneapolis, MN 55455; Division of Biostatistics and Departments of Genetics and Psychiatry, Washington University Medical School, St. Louis, MO 63110; Department of Kinesiology, Indiana University, Bloomington, IN 46202-5192; and Department of Health and Kinesiology, Texas A& M University, College Station, TX, 77843-4243
Submitted for publication February 1997.
Accepted for publication November 1997.
The HERITAGE study is supported by the NHLBI through Grants HL45670 (to C. B.), HL47323 (to A. S. L.), HL47317 (to D. C. R.), HL47327 (to J. S. S.), and HL47321 (to J. H. W.). Jack H. Wilmore was supported by the Margie Gurley Seay Centennial Professorship, and Arthur S. Leon is partially supported by the Henry L. Taylor endowed Professorship in Exercise Science and Health Enhancement.
Address for correspondence: Claude Bouchard, Ph.D., Physical Activity Sciences Laboratory, Kinesiology, PEPS, Laval University, Ste-Foy, Québec G1K 7P4, Canada. E-mail: Claude.Bouchard@kin.msp.ulaval.ca.