AUTHOR=Gasser Benedikt , Franchi Martino V. , Ruoss Severin , Frei Annika , Popp Werner L. , Niederseer David , Catuogno Silvio , Frey Walter O. , Flück Martin 

TITLE=Accelerated Muscle Deoxygenation in Aerobically Fit Subjects During Exhaustive Exercise Is Associated With the ACE Insertion Allele

JOURNAL=Frontiers in Sports and Active Living

VOLUME=4

YEAR=2022

URL=https://www.frontiersin.org/journals/sports-and-active-living/articles/10.3389/fspor.2022.814975

DOI=10.3389/fspor.2022.814975

ISSN=2624-9367

ABSTRACT=<sec><title>Introduction</title><p>The insertion/deletion (I/D) polymorphism in the gene for the major regulator of vascular tone, angiotensin-converting enzyme-insertion/deletion (ACE-I/D) affects muscle capillarization and mitochondrial biogenesis with endurance training. We tested whether changes of leg muscle oxygen saturation (SmO<sub>2</sub>) during exhaustive exercise and recovery would depend on the aerobic fitness status and the ACE I/D polymorphism.</p></sec><sec><title>Methods</title><p>In total, 34 healthy subjects (age: 31.8 ± 10.2 years, 17 male, 17 female) performed an incremental exercise test to exhaustion. SmO<sub>2</sub> in <italic>musculus vastus lateralis</italic> (VAS) and musculus gastrocnemius (GAS) was recorded with near-IR spectroscopy. Effects of the aerobic fitness status (based on a VO<sub>2peak</sub> cutoff value of 50 ml O<sub>2</sub> min<sup>−1</sup> kg<sup>−1</sup>) and the ACE-I/D genotype (detected by PCR) on kinetic parameters of muscle deoxygenation and reoxygenation were assessed with univariate ANOVA.</p></sec><sec><title>Results</title><p>Deoxygenation with exercise was comparable in VAS and GAS (<italic>p</italic> = 0.321). In both leg muscles, deoxygenation and reoxygenation were 1.5-fold higher in the fit than the unfit volunteers. Differences in muscle deoxygenation, but not VO<sub>2</sub>peak, were associated with gender-independent (<italic>p</italic> &gt; 0.58) interaction effects between aerobic fitness × ACE-I/D genotype; being reflected in a 2-fold accelerated deoxygenation of VAS for aerobically fit than unfit ACE-II genotypes and a 2-fold higher deoxygenation of GAS for fit ACE-II genotypes than fit D-allele carriers.</p></sec><sec><title>Discussion</title><p>Aerobically fit subjects demonstrated increased rates of leg muscle deoxygenation and reoxygenation. Together with the higher muscle deoxygenation in aerobically fit ACE-II genotypes, this suggests that an ACE-I/D genotype-based personalization of training protocols might serve to best improve aerobic performance.</p></sec>