.-It has been suggested that genetic variation in the angiotensin-converting enzyme (ACE) gene is associated with physical performance. We studied the association between the ACE insertion (I)/deletion (D) polymorphism and several fitness phenotypes measured before and after 20 wk of a standardized endurance training program in sedentary Caucasian (n ϭ 476) and black (n ϭ 248) subjects. Phenotypes measured were oxygen uptake (V O 2 ), work rate, heart rate, minute ventilation, tidal volume, and blood lactate levels during maximal and submaximal [50 W and at 60 and 80% of maximal V O 2 (V O 2 max )] exercise and stroke volume and cardiac output during submaximal exercise (50 W and at 60% V O 2 max ). The ACE ID polymorphism was typed with the three-primer PCR method. Out of 216 association tests performed on 54 phenotypes in 4 groups of participants, only 11 showed significant (P values from 0.042 to 0.0001) associations with the ACE ID polymorphism. In contrast to previous claims, in Caucasian offspring, the DD homozygotes showed a 14-38% greater increase with training in V O 2 max , V O 2 at 80% of V O 2 max , and all work rate phenotypes and a 36% greater decrease in heart rate at 50 W than did the II homozygotes. No associations were evident in Caucasian parents or black parents or offspring. Thus these data do not support the hypothesis that the ACE ID polymorphism plays a major role in cardiorespiratory endurance. candidate gene; exercise training; responsiveness; insertion/ deletion polymorphism A HIGH LEVEL OF AEROBIC FITNESS is an essential requirement for success in endurance sports. In addition, several studies have shown that a low level of cardiorespiratory endurance is associated with an increased risk for several degenerative diseases (2, 10, 18, 19). Cardiorespiratory fitness, for which maximal oxygen consumption (V O 2 max ) is traditionally recognized as the gold standard, is a multifactorial phenotype influenced by several genetic and environmental factors. Among the environmental factors, regular physical activity is the major contributor to the V O 2 max level. However, several exercise training studies have shown that there are marked interindividual differences in the trainability of cardiorespiratory endurance phenotypes after exposure to an identical training program. For example, after supervised training programs of 15-20 wk in 47 healthy young men, the training responses of V O 2 max ranged from almost no change to an increase of almost 1 liter (3). Similarly, the improvements in total work output during a 90-min ergometer test ranged from 16 to 97% after 20 wk of standardized endurance training (22).This individual variability in exercise responses has been described as a normal biological phenomenon that may reflect genetic diversity (3). Both twin and family studies support the hypothesis of a significant genetic effect on V O 2 max in the sedentary state and other fitness phenotypes. The intrapair resemblance for cardiorespiratory endurance phenotypes is significantly higher in mon...

Background-Alcohol consumption during pregnancy, a known teratogen often associated with drug use and smoking, is a well-known public health concern.

The purpose of this study was to investigate the association between elite endurance athlete (EEA) status and two restriction fragment length polymorphisms (RFLPs) at the muscle-specific creatine kinase (CKMM) gene locus. Genomic DNA was extracted from white blood cells or lymphoblastoid cell lines of 124 unrelated Caucasian male EEA (VO2max > 73 mL.kg-1.min-1) and 115 unrelated Caucasian sedentary male controls (SCON). The genetic polymorphism at the CKMM locus was detected by the polymerase chain reaction and DNA digestion with the NcoI and TaqI restriction endonucleases. The allelic frequencies for the NcoI and TaqI RFLPs were not different (P > 0.05) between EEA and SCON subjects. The three expected genotypes for CKMM-NcoI (1170/1170 bp, 1170/985 + 185 bp, and 985 + 185/985 + 185 bp) and CKMM-TaqI (1170/1170 bp, 1170/1020 + 150 bp, and 1020 + 50/1020 + 150 bp) were observed in the EEA and SCON groups. These genotype frequencies were in Hardy-Weinberg equilibrium, but they were not significantly (P > 0.05) different between the EEA and SCON. A strong (P < 0.001) linkage disequilibrium was detected among the NcoI and TaqI RFLPs in both EEA and SCON. These findings indicate that the skeletal muscle CK-NcoI and CK-TaqI gene polymorphisms are not associated with the elite endurance athlete status.