ABSENCE OF LINKAGE BETWEEN THE TRAINING RESPONSE OF VO2 MAX AND CHROMOSOME 22 MARKERS 1301

An extensive search for linkage between DNA markers and the response to training is currently in progress in the HERITAGE Family Study. Linkage between 7 markers spanning the entire chromosome 22 spaced approximately at each 10 cM (D22S264, D22S274, D22S301, D22S304, D22S421, IL2RB and PDGFB) and VO2 max trainability was examined using the sib-pair linkage method. Markers were genotyped in at least 200 sibpairs derived from 128 adult brothers, age=25 ± 6 yrs, and 138 sisters, age=24 ± 6 yrs (mean± SD) from 86 caucasian families. VO2 max was measured during stationary cycle tests before and after a standardized 20-week endurance training program. Initial VO2 max was 2654 ± 767 ml min-1 or 37 ± 8 ml kg-1 min-1 while training increased VO2 max 430 ± 239 ml min-1. The VO2 max response was adjusted for age and initial VO2 max. No evidence of linkage was detected with any of the markers on chromosome 22. Comparisons of the allelic frequencies at each marker (8-14 alleles/ marker) between low and high responders for VO2 max increase did not reveal any significant difference. Additional markers on other chromosomes are being typed in an attempt to identify DNA markers of the response to training.