Agreement between bioimpedance analysis and ultrasound scanning in body composition assessment.

OBJECTIVES: This study aimed at evaluating the agreement between bioelectrical impedance analysis (BIA) using ABC-02 Medas and A-mode ultrasound (AUS) using BodyMetrix™ BX2000 for fat mass (FM), fat free mass (FFM), and body fat percentage (%BF) in females. METHODS: The cross-sectional, single-center, observational study was performed in 206 female subjects aged 18-67 years. The examination program included measurements of body height and weight along with waist, hip circumferences, and body composition analysis. The measurements were performed by ultrasound scanner and bioimpedance analyzer. RESULTS: We found that 20.9% of women were obese based on BMI (≥30 kg/m2), which was significantly lower when using a criterion based on body fat percentage (%BF ≥ 30%) measured with US (53.4%, p = .0056) or BIA (54.8%, p = .0051). At the group level, both methods were found interchangeable and showed practically negligible differences (0.1% for %BF, 0.5 kg for FM, and 0.4 kg for FFM). Agreement analysis conducted in the whole sample revealed a low level of agreement in estimating %BF (CCC = 0.72 0.77 0.82) and FFM (CCC = 0.81 0.84 0.86), and medium level of agreement in estimating FM (CCC = 0.91 0.93 0.94). The level of agreement in estimating %BF and FFM was improved to the medium level with the use of newly generated prediction equations. CONCLUSION: Thus, the proposed equations can be used for conversion of body composition results obtained by AUS into the BIA data.

Genetics of Exercise and Diet-Induced Fat Loss Efficiency: A Systematic Review.

Physical exercise and dieting are well-known and effective methods for fat loss and improving cardiovascular health. However, different individuals often react differently to the same exercise regimen or dietary plan. While specific individuals may undergo substantial fat loss, others may observe only limited effects. A wide range of inter-individual variability in weight gain and changes in body composition induced by physical exercises and diets led to an investigation into the genetic factors that may contribute to the individual variations in such responses. This systematic review aimed at identifying the genetic markers associated with fat loss resulting from diet or exercise. A search of the current literature was performed using the PubMed database. Forty-seven articles met the inclusion criteria when assessing genetic markers associated with weight loss efficiency in response to different types of exercises and diets. Overall, we identified 30 genetic markers of fat-loss efficiency in response to different kinds of diets and 24 in response to exercise. Most studies (n = 46) used the candidate gene approach. We should aspire to the customized selection of exercise and dietary plans for each individual to prevent and treat obesity.

Association of gene polymorphisms with body weight changes in prediabetic patients.

BACKGROUND: Recent research has demonstrated that Type 2 Diabetes (T2D) risk is influenced by a number of common polymorphisms, including MC4R rs17782313, PPARG rs1801282, and TCF7L2 rs7903146. Knowledge of the association between these single nucleotide polymorphisms (SNPs) and body weight changes in different forms of prediabetes treatment is still limited. The aim of this study was to investigate the association of polymorphisms within the MC4R, PPARG, and TCF7L2 genes on the risk of carbohydrate metabolism disorders and body composition changes in overweight or obese patients with early carbohydrate metabolism disorders. METHODS AND RESULTS: From 327 patients, a subgroup of 81 prediabetic female patients (48.7 ± 14.8 years) of Eastern European descent participated in a 3-month study comprised of diet therapy or diet therapy accompanied with metformin treatment. Bioelectrical impedance analysis and genotyping of MC4R rs17782313, PPARG rs1801282, and TCF7L2 rs7903146 polymorphisms were performed. The MC4R CC and TCF7L2 TT genotypes were associated with increased risk of T2D (OR = 1.46, p = 0.05 and OR = 2.47, p = 0.006, respectively). PPARG CC homozygotes experienced increased weight loss; however, no additional improvements were experienced with the addition of metformin. MC4R TT homozygotes who took metformin alongside dietary intervention experienced increased weight loss and reductions in fat mass (p < 0.05). CONCLUSIONS: We have shown that the obesity-protective alleles (MC4R T and PPARG C) were positively associated with weight loss efficiency. Furthermore, we confirmed the previous association of the MC4R C and TCF7L2 T alleles with T2D risk.

Genomic predictors of testosterone levels are associated with muscle fiber size and strength.

PURPOSE: Circulating testosterone levels are a heritable trait with anabolic properties in various tissues, including skeletal muscle. So far, hundreds of single nucleotide polymorphisms (SNPs) associated with testosterone levels have been identified in nonathletic populations. The aim of the present study was to test the association of 822 testosterone-increasing SNPs with muscle-related traits (muscle fiber size, fat-free mass and handgrip strength) and to validate the identified SNPs in independent cohorts of strength and power athletes. METHODS: One hundred and forty-eight physically active individuals (47 females, 101 males) were assessed for cross-sectional area (CSA) of fast-twitch muscle fibers. Significant SNPs were further assessed for fat-free mass and handgrip strength in > 354,000 participants from the UK Biobank cohort. The validation cohorts included Russian elite athletes. RESULTS: From an initial panel of 822 SNPs, we identified five testosterone-increasing alleles (DOCK3 rs77031559 G, ESR1 rs190930099 G, GLIS3 rs34706136 TG, GRAMD1B rs850294 T, TRAIP rs62260729 C) nominally associated (P < 0.05) with CSA of fast-twitch muscle fibers, fat-free mass and handgrip strength. Based on these five SNPs, the number of testosterone-increasing alleles was positively associated with testosterone levels in male athletes (P = 0.048) and greater strength performance in weightlifters (P = 0.017). Moreover, the proportion of participants with ≥ 2 testosterone-increasing alleles was higher in power athletes compared to controls (68.9 vs. 55.6%; P = 0.012). CONCLUSION: Testosterone-related SNPs are associated with muscle fiber size, fat-free mass and strength, which combined can partially contribute to a greater predisposition to strength/power sports.

Polygenic Profile of Elite Strength Athletes.

ABSTRACT: Moreland, E, Borisov, OV, Semenova, EA, Larin, AK, Andryushchenko, ON, Andryushchenko, LB, Generozov, EV, Williams, AG, and Ahmetov, II. Polygenic profile of elite strength athletes. J Strength Cond Res 36(9): 2509-2514, 2022-Strength is a heritable trait with unknown polygenic nature. So far, more than 200 DNA polymorphisms associated with strength/power phenotypes have been identified majorly involving nonathletic populations. The aim of the present study was to investigate individually and in combination the association of 217 DNA polymorphisms previously identified as markers for strength/power phenotypes with elite strength athlete status. A case-control study involved 83 Russian professional strength athletes (53 weightlifters, 30 powerlifters), 209 Russian and 503 European controls. Genotyping was conducted using micro-array analysis. Twenty-eight DNA polymorphisms (located near or in ABHD17C , ACTG1 , ADCY3 , ADPGK , ANGPT2 , ARPP21 , BCDIN3D , CRTAC1 , DHODH , GBE1 , IGF1 , IL6 , ITPR1 , KIF1B , LRPPRC , MMS22L , MTHFR , NPIPB6 , PHACTR1 , PLEKHB1 , PPARG , PPARGC1A , R3HDM1 , RASGRF1 , RMC1 , SLC39A8 , TFAP2D , ZKSCAN5 genes) were identified to have an association with strength athlete status. Next, to assess the combined impact of all 28 DNA polymorphisms, all athletes were classified according to the number of "strength" alleles they possessed. All highly elite strength athletes were carriers of at least 22 (up to 34) "strength" alleles, whereas 27.8% of Russian controls had less than 22 "strength" alleles ( p < 0.0001). The proportion of subjects with a high (≥26) number of "strength" alleles was significantly greater in highly elite strength athletes (84.8%) compared with less successful strength athletes (64.9%; odd ratio [OR] = 3.0, p = 0.042), Russian (26.3%; OR = 15.6, p < 0.0001) or European (37.8%; OR = 6.4, p < 0.0001) controls. This is the first study to demonstrate that the likelihood of becoming an elite strength athlete depends on the carriage of a high number of strength-related alleles.

The BDNF-Increasing Allele is Associated With Increased Proportion of Fast-Twitch Muscle Fibers, Handgrip Strength, and Power Athlete Status.

ABSTRACT: Guilherme, JPLF, Semenova, EA, Borisov, OV, Kostryukova, ES, Vepkhvadze, TF, Lysenko, EA, Andryushchenko, ON, Andryushchenko, LB, Lednev, EM, Larin, AK, Bondareva, EA, Generozov, EV, and Ahmetov, II. The BDNF-increasing allele is associated with increased proportion of fast-twitch muscle fibers, handgrip strength, and power athlete status. J Strength Cond Res 36(7): 1884-1889, 2022-The brain-derived neurotrophic factor (BDNF) is involved in neurogenesis and formation of regenerated myofibers following injury or damage. A recent study suggested that the BDNF overexpression increases the proportion of fast-twitch muscle fibers, while the BDNF deletion promotes a fast-to-slow transition. The purpose of this study was to evaluate the association between the BDNF gene rs10501089 polymorphism (associated with blood BDNF levels), muscle fiber composition, and power athlete status. Muscle fiber composition was determined in 164 physically active individuals (113 men, 51 women). BDNF genotype and allele frequencies were compared between 508 Russian power athletes, 178 endurance athletes, and 190 controls. We found that carriers of the minor A-allele (the BDNF-increasing allele) had significantly higher percentage of fast-twitch muscle fibers than individuals homozygous for the G-allele (males: 64.3 [7.8] vs. 50.3 [15.8]%, p = 0.0015; all subjects: 64.1 ± 7.9 vs. 49.6 ± 14.7%, p = 0.0002). Furthermore, the A-allele was associated (p = 0.036) with greater handgrip strength in a sub-group of physically active subjects (n = 83) and over-represented in power athletes compared with controls (7.7 vs. 2.4%, p = 0.0001). The presence of the A-allele (i.e., AA+AG genotypes) rather than GG genotype increased the odds ratio of being a power athlete compared with controls (odds ratio [OR]: 3.43, p = 0.00071) or endurance athletes (OR: 2.36, p = 0.0081). In conclusion, the rs10501089 A-allele is associated with increased proportion of fast-twitch muscle fibers and greater handgrip strength, and these may explain, in part, the association between the AA/AG genotypes and power athlete status.

Genetic profile of sports climbing athletes from three different ethnicities.

This study aimed to investigate the ACTN3 R577X, ACE I/D, CKM rs8111989, and TRHR rs7832552 genotypes in climbers and controls in three ethnicities. The study consisted of 258 climbers (Japanese, n = 100; Polish, n = 128; Russian, n = 30) and 1151 controls (Japanese: n = 332, Polish: n = 635, Russian: n = 184). Genotyping results were analyzed using the TaqMan approach in Japanese and Polish subjects and HumanOmni1-Quad Bead Chips in Russian subjects. There were no significant differences in ACTN3 R577X and ACE I/D polymorphism distribution between climbers and controls in any ethnic cohort or model. The frequencies of the C allele in the CKM polymorphism and the T allele in the TRHR polymorphism were higher in climbers than in controls only in the Russian cohort (p = 0.045 and p = 0.039, respectively). The results of the meta-analysis on three cohorts showed that the frequency of XX + RX genotypes in the ACTN3 R577X polymorphism was significantly higher in climbers than that in the controls (p = 0.01). The X allele of the ACTN3 R577X polymorphism was associated with sport climbing status, as assessed using a meta-analysis of climbers across three different ethnicities.

Androgen receptor gene microsatellite polymorphism is associated with muscle mass and strength in bodybuilders and power athlete status.

BACKGROUND: The androgen receptor (AR) gene contains a polymorphic trinucleotide (CAG) microsatellite repeat sequence (short or long alleles) that has been associated with fat-free mass in untrained men, which needs to be replicated in athletic cohorts. AIM: The purpose of this study was to explore the AR (CAG)n polymorphism in trained individuals. SUBJECTS AND METHODS: A total of 61 professional bodybuilders (40 males, 21 females), 73 elite male sprinters and weightlifters and 186 male controls were enrolled in this study. The influence of the AR (CAG)n polymorphism on muscle mass and strength was assessed in bodybuilders, while the frequencies of AR (CAG)n alleles were compared between power athletes and non-athletes. RESULTS: The polymorphism was associated with anthropometric and strength measurements in bodybuilders of both genders. Those with ≥21 CAG repeats (i.e. carriers of long alleles) exhibited greater (p < 0.05) body mass index, absolute muscle mass, arm/thigh circumference and upper/lower limb strength compared to those with <21 CAG repeats. Furthermore, carriers of ≥21 CAG repeats were more frequent among power athletes compared to controls (p = 0.0076). CONCLUSIONS: Long alleles of the AR (CAG)n polymorphism were associated with greater muscle mass and strength in bodybuilders, and power athlete status.

Association of muscle fiber composition with health and exercise-related traits in athletes and untrained subjects.

Skeletal muscle is a heterogenous and metabolically active tissue, the composition of which is associated with multiple traits. The aim of the study was to determine whether there are additional health and exercise-related traits associated with muscle fiber composition in athletes and non-athletes. This study recruited 164 Russian participants (51 endurance and 48 power athletes; 65 controls). Vastus lateralis muscle fiber composition was assessed by immunohistochemistry. Slow-twitch muscle fiber percentage (STMF%) was significantly greater in endurance than power athletes and non-athletes, and in non-athlete females than males. STMF% was positively associated with athletes' training frequency, non-athletes' and endurance athletes' age, endurance athletes' competition level and chest depth, and power athletes' training age. STMF% was negatively associated with diastolic blood pressure in power athletes and with systolic blood pressure and reaction time in non-athletes. In all participants, STMF% was positively associated with age, tolerance to long distance exercise, chest depth and fracture incidence, and negatively with systolic blood pressure and resting heart rate. Age, sex and training frequency explained 10.6% and 13.2% of the variance in STMF% in endurance and power athletes, respectively. This is one of the most comprehensive studies involving athletes and untrained subjects and provides novel information concerning associations of increased STMF percentage with lower resting heart rate, better tolerance to long distances, faster reaction time and larger chest depth. On the other hand, the increased percentage of fast-twitch muscle fibers was associated with rare fracture incidence.

Prediction of muscle fiber composition using multiple repetition testing.

Direct determination of muscle fiber composition is invasive and expensive, with indirect methods also requiring specialist resources and expertise. Performing resistance exercises at 80% 1RM is suggested as a means of indirectly estimating muscle fiber composition, though this hypothesis has never been validated against a direct method. The aim of the study was to investigate the relationship between the number of completed repetitions at 80% 1RM of back squat exercise and muscle fiber composition. Thirty recreationally active participants' (10 females, 20 males) 1RM back squat load was determined, before the number of consecutive repetitions at 80% 1RM was recorded. The relationship between the number of repetitions and the percentage of fast-twitch fibers from vastus lateralis was investigated. The number of completed repetitions ranged from 5 to 15 and was independent of sex, age, 1RM, training frequency, training type, training experience, BMI or muscle fiber cross-sectional area. The percentage of fast-twitch muscle fibers was inversely correlated with the number of repetitions completed (r = -0.38, P = 0.039). Participants achieving 5 to 8 repetitions (n = 10) had significantly more fast-twitch muscle fibers (57.5 ± 9.5 vs 44.4 ± 11.9%, P = 0.013) than those achieving 11-15 repetitions (n = 11). The remaining participants achieved 9 or 10 repetitions (n = 9) and on average had equal proportion of fast- and slow-twitch muscle fibers. In conclusion, the number of completed repetitions at 80% of 1RM is moderately correlated with muscle fiber composition.

The MCT1 gene Glu490Asp polymorphism (rs1049434) is associated with endurance athlete status, lower blood lactate accumulation and higher maximum oxygen uptake.

The purpose of this study was to explore the association of the MCT1 gene Glu490Asp polymorphism (rs1049434) with athletic status and performance of endurance athletes. A total of 1,208 Brazilians (318 endurance athletes and 890 non-athletes) and 867 Europeans (315 endurance athletes and 552 non-athletes) were evaluated in a case-control approach. Brazilian participants were classified based on self-declared ethnicity to test whether the polymorphism was different between Caucasians and Afro-descendants. Moreover, 66 Hungarian athletes underwent an incremental test until exhaustion to assess blood lactate levels, while 46 Russian athletes had their maximum oxygen uptake ( V ⋅ O 2 max ) compared between genotypes. In the Brazilian cohort, the major T-allele was more frequent in Caucasian top-level competitors compared to their counterparts of lower competitive level (P = 0.039), and in Afro-descendant athletes compared to non-athletes (P = 0.015). Similarly, the T-allele was more frequent in European athletes (P = 0.029). Meta-analysis of the Brazilian and European cohorts confirmed that the T-allele is over-represented in endurance athletes (OR: 1.48, P = 0.03), especially when Afro-descendant athletes were included in the meta-analysis (OR: 1.58, P = 0.005). Furthermore, carriers of the T/T genotype accumulated less blood lactate in response to intense effort (P < 0.01) and exhibited higher V ⋅ O 2 max (P = 0.04). In conclusion, the Glu490Asp polymorphism was associated with endurance athletic status and performance. Our findings suggest that, although ethnic differences may exist, the presence of the major T-allele (i.e., the Glu-490 allele) favours endurance performance more than the mutant A-allele (i.e., the 490-Asp allele).

Striated muscle-specific serine/threonine-protein kinase beta segregates with high versus low responsiveness to endurance exercise training.

Bidirectional selection for either high or low responsiveness to endurance running has created divergent rat phenotypes of high-response trainers (HRT) and low-response trainers (LRT). We conducted proteome profiling of HRT and LRT gastrocnemius of 10 female rats (body weight 279 ± 35 g; n = 5 LRT and n = 5 HRT) from generation 8 of selection. Differential analysis of soluble proteins from gastrocnemius was conducted by label-free quantitation. Genetic association studies were conducted in 384 Russian international-level athletes (age 23.8 ± 3.4 yr; 202 men and 182 women) stratified to endurance or power disciplines. Proteomic analysis encompassed 1,024 proteins, 76 of which exhibited statistically significant (P < 0.05, false discovery rate <1%) differences between HRT and LRT muscle. There was significant enrichment of enzymes involved in glycolysis/gluconeogenesis in LRT muscle but no enrichment of gene ontology phrases in HRT muscle. Striated muscle-specific serine/threonine-protein kinase-beta (SPEG-ß) exhibited the greatest difference in abundance and was 2.64-fold greater (P = 0.0014) in HRT muscle. Coimmunoprecipitation identified 24 potential binding partners of SPEG-ß in HRT muscle. The frequency of the G variant of the rs7564856 polymorphism that increases SPEG gene expression was significantly greater (32.9 vs. 23.8%; OR = 1.6, P = 0.009) in international-level endurance athletes (n = 258) compared with power athletes (n = 126) and was significantly associated (ß = 8.345, P = 0.0048) with a greater proportion of slow-twitch fibers in vastus lateralis of female endurance athletes. Coimmunoprecipitation of SPEG-ß in HRT muscle discovered putative interacting proteins that link with previously reported differences in transforming growth factor-ß signaling in exercised muscle.

PPARGC1A gene polymorphism is associated with exercise-induced fat loss.

Obesity is a widespread problem within modern society, serving to increase the risk of cardiovascular, metabolic, and neurodegenerative disorders. Peroxisome proliferator-activated receptor gamma (PPARγ) and PPARγ coactivator 1 α (PGC1α) play a key role in the regulation of cellular energy metabolism and is implicated in the pathology of these diseases. This study examined the association between polymorphisms of the PPARG and PPARGC1A genes and individual variability in weight loss in response to physical activity intervention. 39 obese Ukrainian women (44.4 ± 7.5 years, BMI > 30.0 kg/m2) undertook a 3-month fitness program whilst following a hypocaloric diet (~ 1500 cal). Anthropometric and biochemical measurements took place before and after the program. Single nucleotide polymorphisms within or near PPARG (n = 94) and PPARGC1A (n = 138) were identified and expression of PPARG mRNA was measured via reverse transcription and amplification. The association between DNA polymorphisms and exercise-induced weight loss, initial body mass, biochemistry and PPARG expression was determined using one-way analysis of variance (ANOVA). The present intervention induced significant fat loss in all participants (total fat: 40.3 ± 5.3 vs 36.4 ± 5.7%; P < 0.00001). Only one polymorphism (rs17650401 C/T) within the PPARGC1A gene was found to be associated with fat loss efficiency after correction for multiple testing, with T allele carriers showing the greatest reduction in body fat percentage (2.5-fold; P = 0.00013) compared to non-carriers. PPARGC1A (rs17650401) is associated with fat loss efficiency of the fitness program in obese women. Further studies are warranted to test whether this variation is associated with fat oxidation.

The association of HFE gene H63D polymorphism with endurance athlete status and aerobic capacity: novel findings and a meta-analysis.

PURPOSE: Iron is an important component of the oxygen-binding proteins and may be critical to optimal athletic performance. Previous studies have suggested that the G allele of C/G rare variant (rs1799945), which causes H63D amino acid replacement, in the HFE is associated with elevated iron indexes and may give some advantage in endurance-oriented sports. The aim of the present study was to investigate the association between the HFE H63D polymorphism and elite endurance athlete status in Japanese and Russian populations, aerobic capacity and to perform a meta-analysis using current findings and three previous studies. METHODS: The study involved 315 international-level endurance athletes (255 Russian and 60 Japanese) and 809 healthy controls (405 Russian and 404 Japanese). Genotyping was performed using micro-array analysis or by PCR. VO2max in 46 male Russian endurance athletes was determined using gas analysis system. RESULTS: The frequency of the iron-increasing CG/GG genotypes was significantly higher in Russian (38.0 vs 24.9%; OR 1.85, P = 0.0003) and Japanese (13.3 vs 5.0%; OR 2.95, P = 0.011) endurance athletes compared to ethnically matched controls. The meta-analysis using five cohorts (two French, Japanese, Spanish, and Russian; 586 athletes and 1416 controls) showed significant prevalence of the CG/GG genotypes in endurance athletes compared to controls (OR 1.96, 95% CI 1.58-2.45; P = 1.7 × 10-9). Furthermore, the HFE G allele was associated with high V̇O2max in male athletes [CC: 61.8 (6.1), CG/GG: 66.3 (7.8) ml/min/kg; P = 0.036]. CONCLUSIONS: We have shown that the HFE H63D polymorphism is strongly associated with elite endurance athlete status, regardless ethnicities and aerobic capacity in Russian athletes.

The GALNTL6 Gene rs558129 Polymorphism Is Associated With Power Performance.

Díaz, J, Álvarez Herms, J, Castañeda, A, Larruskain, J, Ramírez de la Piscina, X, Borisov, OV, Semenova, EA, Kostryukova, ES, Kulemin, NA, Andryushchenko, ON, Larin, AK, Andryushchenko, LB, Generozov, EV, Ahmetov, II, and Odriozola, A. The GALNTL6 gene rs558129 polymorphism is associated with power performance. J Strength Cond Res 34(11): 3031-3036, 2020-The largest genome-wide association study to date in sports genomics showed that endurance athletes were 1.23 times more likely to possess the C allele of the single nucleotide polymorphism rs558129 of N-acetylgalactosaminyltransferase-like 6 gene (GALNTL6), compared with controls. Nevertheless, no further study has investigated GALNTL6 gene in relation to physical performance. Considering that previous research has shown that the same polymorphism can be associated with both endurance and power phenotypes (ACTN3, ACE, and PPARA), we investigated the association between GALNTL6 rs558129 polymorphism and power performance. According to this objective we conducted 2 global studies regarding 2 different communities of athletes in Spain and Russia. The first study involved 85 Caucasian physically active men from the north of Spain to perform a Wingate anaerobic test (WAnT). In the second study we compared allelic frequencies between 173 Russian power athletes (49 strength and 124 speed-strength athletes), 169 endurance athletes, and 201 controls. We found that physically active men with the T allele of GALNTL6 rs558129 had 5.03-6.97% higher power values compared with those with the CC genotype (p < 0.05). Consistent with these findings, we have shown that the T allele was over-represented in power athletes (37.0%) compared with endurance athletes (29.3%; OR = 1.4, p = 0.032) and controls (28.6%; OR = 1.5, p = 0.015). Furthermore, the highest frequency of the T allele was observed in strength athletes (43.9%; odds ratio [OR] = 1.9, p = 0.0067 compared with endurance athletes; OR = 2.0, p = 0.0036 compared with controls). In conclusion, our data suggest that the GALNTL6 rs558129 T allele can be favorable for anaerobic performance and strength athletes. In addition, we propose a new possible functional role of GALNTL6 rs558129, gut microbiome regarding short-chain fatty acid regulation and their anti-inflammatory and resynthesis functions. Nevertheless, further studies are required to understand the mechanisms involved.

Whole genome sequencing of elite athletes.

Whole genome sequencing (WGS) has great potential to explore all possible DNA variants associated with physical performance, psychological traits and health conditions of athletes. Here we present, for the first time, annotation of genomic variants of elite athletes, based on the WGS of 20 Tatar male wrestlers. The maximum number of high-quality variants per sample was over 3.8 M for single nucleotide polymorphisms (SNPs) and about 0.64 M for indels. The maximum number of nonsense mutations was 148 single nucleotide variants (SNVs) per individual. Athletes' genomes on average contained 18.9 nonsense SNPs in a homozygous state per sample, while non-athletes' exomes (Tatar controls, n = 19) contained 18 nonsense SNPs. Finally, we applied genomic data for the association analysis and used reaction time (RT) as an example. Out of 1884 known genome-wide significant SNPs related to RT, we identified four SNPs (KIF27 rs10125715, APC rs518013, TMEM229A rs7783359, LRRN3 rs80054135) associated with RT in wrestlers. The cumulative number of favourable alleles (KIF27 A, APC A, TMEM229A T, LRRN3 T) was significantly correlated with RT both in wrestlers (P = 0.0003) and an independent cohort (n = 43) of physically active subjects (P = 0.029). Furthermore, we found that the frequencies of the APC A (53.3 vs 44.0%, P = 0.033) and LRRN3 T (7.5 vs 2.8%, P = 0.009) alleles were significantly higher in elite athletes (n = 107) involved in sports with RT as an essential component of performance (combat sports, table tennis and volleyball) compared to less successful (n = 176) athletes. The LRRN3 T allele was also over-represented in elite athletes (7.5%) in comparison with 189 controls (2.9%, P = 0.009). In conclusion, we present the first WGS study of athletes showing that WGS can be applied in sport and exercise science.

UBR5 is a novel E3 ubiquitin ligase involved in skeletal muscle hypertrophy and recovery from atrophy.

KEY POINTS: We have recently identified that a HECT domain E3 ubiquitin ligase, named UBR5, is altered epigenetically (via DNA methylation) after human skeletal muscle hypertrophy, where its gene expression is positively correlated with increasing lean leg mass after training and retraining. In the present study we extensively investigate this novel and uncharacterised E3 ubiquitin ligase (UBR5) in skeletal muscle atrophy, recovery from atrophy and injury, anabolism and hypertrophy. We demonstrated that UBR5 was epigenetically altered via DNA methylation during recovery from atrophy. We also determined that UBR5 was alternatively regulated versus well characterised E3 ligases, MuRF1/MAFbx, at the gene expression level during atrophy, recovery from atrophy and hypertrophy. UBR5 also increased at the protein level during recovery from atrophy and injury, hypertrophy and during human muscle cell differentiation. Finally, in humans, genetic variations of the UBR5 gene were strongly associated with larger fast-twitch muscle fibres and strength/power performance versus endurance/untrained phenotypes. ABSTRACT: We aimed to investigate a novel and uncharacterized E3 ubiquitin ligase in skeletal muscle atrophy, recovery from atrophy/injury, anabolism and hypertrophy. We demonstrated an alternate gene expression profile for UBR5 vs. well characterized E3-ligases, MuRF1/MAFbx, where, after atrophy evoked by continuous-low-frequency electrical-stimulation in rats, MuRF1/MAFbx were both elevated, yet UBR5 was unchanged. Furthermore, after recovery of muscle mass post TTX-induced atrophy in rats, UBR5 was hypomethylated and increased at the gene expression level, whereas a suppression of MuRF1/MAFbx was observed. At the protein level, we also demonstrated a significant increase in UBR5 after recovery of muscle mass from hindlimb unloading in both adult and aged rats, as well as after recovery from atrophy evoked by nerve crush injury in mice. During anabolism and hypertrophy, UBR5 gene expression increased following acute loading in three-dimensional bioengineered mouse muscle in vitro, and after chronic electrical stimulation-induced hypertrophy in rats in vivo, without increases in MuRF1/MAFbx. Additionally, UBR5 protein abundance increased following functional overload-induced hypertrophy of the plantaris muscle in mice and during differentiation of primary human muscle cells. Finally, in humans, genetic association studies (>700,000 single nucleotide polymorphisms) demonstrated that the A alleles of rs10505025 and rs4734621 single nucleotide polymorphisms in the UBR5 gene were strongly associated with larger cross-sectional area of fast-twitch muscle fibres and favoured strength/power vs. endurance/untrained phenotypes. Overall, we suggest that: (i) UBR5 comprises a novel E3 ubiquitin ligase that is inversely regulated to MuRF1/MAFbx; (ii) UBR5 is epigenetically regulated; and (iii) UBR5 is elevated at both the gene expression and protein level during recovery from skeletal muscle atrophy and hypertrophy.

The A-allele of the FTO Gene rs9939609 Polymorphism Is Associated With Decreased Proportion of Slow Oxidative Muscle Fibers and Over-represented in Heavier Athletes.

Guilherme, JPLF, Egorova, ES, Semenova, EA, Kostryukova, ES, Kulemin, NA, Borisov, OV, Khabibova, SA, Larin, AK, Ospanova, EA, Pavlenko, AV, Lyubaeva, EV, Popov, DV, Lysenko, EA, Vepkhvadze, TF, Lednev, EM, Govorun, VM, Generozov, EV, Ahmetov, II, and Lancha Junior, AH. The A-allele of the FTO gene rs9939609 polymorphism is associated with decreased proportion of slow oxidative muscle fibers and over-represented in heavier athletes. J Strength Cond Res 33(3): 691-700, 2019-The purpose of this study was to explore the frequency of the FTO T > A (rs9939609) polymorphism in elite athletes from 2 cohorts (Brazil and Russia), as well as to find a relationship between FTO genotypes and muscle fiber composition. A total of 677 athletes and 652 nonathletes were evaluated in the Brazilian cohort, whereas a total of 920 athletes and 754 nonathletes were evaluated in the Russian cohort. It was found a trend for a lower frequency of A/A genotype in long-distance athletes compared with nonathletes (odds ratio [OR]: 0.65; p = 0.054). By contrast, it was found an increased frequency of the A-allele in Russian power athletes. The presence of the T/A + A/A genotypes rather than T/T increased the OR of being a Russian power athlete compared with matched nonathletes (OR: 1.45; p = 0.002). Different from that observed in combat sports athletes of lighter weight categories, the A-allele was also over-represented in combat sports athletes of heavier weight categories. The presence of the T/A + A/A genotypes rather than T/T increased the OR of being a combat sports athlete of heavier weight categories compared with nonathletes (OR: 1.79; p = 0.018). Regarding the muscle fibers, we found that carriers of the A/A genotype had less slow-twitch muscle fibers than T-allele carriers (p = 0.029). In conclusion, the A/A genotype of the FTO T > A polymorphism is under-represented in athletes more reliant on a lean phenotype and associated with decreased proportion of slow-twitch muscle fibers, while is over-represented in strength and heavier athletes.

Three DNA Polymorphisms Previously Identified as Markers for Handgrip Strength Are Associated With Strength in Weightlifters and Muscle Fiber Hypertrophy.

Grishina, EE, Zmijewski, P, Semenova, EA, Cieszczyk, P, Huminska-Lisowska, K, Michalowska-Sawczyn, M, Maculewicz, E, Crewther, B, Orysiak, J, Kostryukova, ES, Kulemin, NA, Borisov, OV, Khabibova, SA, Larin, AK, Pavlenko, AV, Lyubaeva, EV, Popov, DV, Lysenko, EA, Vepkhvadze, TF, Lednev, EM, Bondareva, EA, Erskine, RM, Generozov, EV, and Ahmetov, II. Three DNA polymorphisms previously identified as markers for handgrip strength are associated with strength in weightlifters and muscle fiber hypertrophy. J Strength Cond Res 33(10): 2602-2607, 2019-Muscle strength is a highly heritable trait. So far, 196 single nucleotide polymorphisms (SNPs) associated with handgrip strength have been identified in 3 genome-wide association studies. The aim of our study was to validate the association of 35 SNPs with strength of elite Russian weightlifters and replicate the study in Polish weightlifters. Genotyping was performed using micro-array analysis or real-time polymerase chain reaction. We found that the rs12055409 G-allele near the MLN gene (p = 0.004), the rs4626333 G-allele near the ZNF608 gene (p = 0.0338), and the rs2273555 A-allele in the GBF1 gene (p = 0.0099) were associated with greater competition results (total lifts in snatch and clean and jerk adjusted for sex and weight) in 53 elite Russian weightlifters. In the replication study of 76 sub-elite Polish weightlifters, rs4626333 GG homozygotes demonstrated greater competition results (p = 0.0155) and relative muscle mass (p = 0.046), adjusted for sex, weight, and age, compared with carriers of the A-allele. In the following studies, we tested the hypotheses that these SNPs would be associated with skeletal muscle hypertrophy and handgrip strength. We found that the number of strength-associated alleles was positively associated with fast-twitch muscle fiber cross-sectional area in the independent cohort of 20 male power athletes (p = 0.021) and with handgrip strength in 87 physically active individuals (p = 0.015). In conclusion, by replicating previous findings in 4 independent studies, we demonstrate that the rs12055409 G-, rs4626333 G-, and rs2273555 A-alleles are associated with higher levels of strength, muscle mass, and muscle fiber size.

A Genome-Wide Association Study of Sprint Performance in Elite Youth Football Players.

Pickering, C, Suraci, B, Semenova, EA, Boulygina, EA, Kostryukova, ES, Kulemin, NA, Borisov, OV, Khabibova, SA, Larin, AK, Pavlenko, AV, Lyubaeva, EV, Popov, DV, Lysenko, EA, Vepkhvadze, TF, Lednev, EM, Leonska-Duniec, A, Pajak, B, Chycki, J, Moska, W, Lulinska-Kuklik, E, Dornowski, M, Maszczyk, A, Bradley, B, Kana-ah, A, Cieszczyk, P, Generozov, EV, and Ahmetov, II. A genome-wide association study of sprint performance in elite youth football players. J Strength Cond Res 33(9): 2344-2351, 2019-Sprint speed is an important component of football performance, with teams often placing a high value on sprint and acceleration ability. The aim of this study was to undertake the first genome-wide association study to identify genetic variants associated with sprint test performance in elite youth football players and to further validate the obtained results in additional studies. Using micro-array data (600 K-1.14 M single nucleotide polymorphisms [SNPs]) of 1,206 subjects, we identified 12 SNPs with suggestive significance after passing replication criteria. The polymorphism rs55743914 located in the PTPRK gene was found as the most significant for 5-m sprint test (p = 7.7 × 10). Seven of the discovered SNPs were also associated with sprint test performance in a cohort of 126 Polish women, and 4 were associated with power athlete status in a cohort of 399 elite Russian athletes. Six SNPs were associated with muscle fiber type in a cohort of 96 Russian subjects. We also examined genotype distributions and possible associations for 16 SNPs previously linked with sprint performance. Four SNPs (AGT rs699, HSD17B14 rs7247312, IGF2 rs680, and IL6 rs1800795) were associated with sprint test performance in this cohort. In addition, the G alleles of 2 SNPs in ADRB2 (rs1042713 & rs1042714) were significantly over-represented in these players compared with British and European controls. These results suggest that there is a genetic influence on sprint test performance in footballers, and identifies some of the genetic variants that help explain this influence.