[Association of the muscle-specific creatine kinase (CKMM) gene polymorphism with physical performance of athletes]

The aim of the study was to investigate allele and genotype distributions of the muscle-specific creatine kinase gene (CKMM) A/G polymorphism in athletes (n = 384) and controls (n = 1116), and to find interrelation between genotypes and aerobic capacity in rowers (n = 85). Genotyping was performed by restriction fragment length polymorphism analysis. Aerobic capacity (maximal oxygen consumption (VO2(max)) and maximal power production capacity (W(max was determined using an incremental test to exhaustion by rower ergometer. The frequencies of CKMM A allele and AA genotype were significantly higher in endurance-oriented athletes (n = 176) than in controls (A allele: 78.7% vs. 65.4%; p < 0.0001; AA genotype: 59.7% vs. 44.2%; p = 0.0003). On the other hand, GG genotype was more prevalent in weightlifters (n = 74) in comparison with controls (31.1% vs. 13.4%; p = 0.0001). Furthermore, CKMM AA genotype was associated with high values of VO2(max) (AA - 58.98 (3.44) ml/kg/min, GA - 56.99 (4.36) ml/kg/min, GG - 52.87 (4.32) ml/kg/min, p = 0.0097). Thus, CKMM gene A/G polymorphism is associated with physical performance of athletes.

[Allelic polymorphism of Pro582-->Ser HIF-1alpha to exercise-induced hypoxia adaptation]

The features of the distribution of allelic variants Pro582-->Ser polymorphism in HIF-1alpha gene in groups of athletes involved in sports, with different types of compensatory mechanisms of adaptation to hypoxic stress were investigated. During the study 191 highly qualified athletes were examined. The control group included 260 subjects, not engaged in sports. The possibility of using this polymorphism as a molecular genetic marker of susceptibility to a variety of sports pursuits. The distribution of allelic variants of HIF-1alpha Pro582-->Ser polymorphism of the residents of Ukraine was investigated. Found that the Pro/Pro genotype contributes to endurance performance. It is shown that the 582Ser gene HIF-1alpha is a marker of predisposition to power sports. The result revealed that the frequency of Ser allele of HIF-1alpha (16% vs 7%, P=0.03) was significantly higher in the power-orientated athletes compared to endurance athletes.

Long-term swimming in an inescapable stressful environment attenuates the stimulatory effect of endurance swimming on duodenal calcium absorption in rats

Endurance swimming is known to increase duodenal calcium absorption in normal rats and bone strength in estrogen-deficient rats. Because the stress resulting from forced training often attenuates the stimulatory effect of exercise, swimming in an inescapable chamber should reveal both the positive effect of the exercise and the negative effect of stress. In the work reported herein, swimming rats showed no signs of stress during 2 weeks of training. However, stress response gradually developed thereafter and peaked at weeks 6 and 7. In rats swimming for 2 weeks, transcellular duodenal calcium transport was enhanced ~2-fold. In contrast, calcium absorption was reduced in rats swimming for 8 weeks, consistent with the absence of swimming-induced upregulation of calcium transporter genes in the 8-week group. In conclusion, prolonged stress hindered the stimulatory effect of swimming on duodenal calcium absorption, and thus endurance exercise should be performed without forced training or stress to retain its beneficial effect on calcium metabolism.

Cordyceps sinensis promotes exercise endurance capacity of rats by activating skeletal muscle metabolic regulators

ETHNOPHARMACOLOGICAL RELEVANCE

Cordyceps sinensis is a traditional Chinese medicine used for promotion of health, longevity and athletic power. However, the molecular mechanism for anti-fatigue activity and physical fitness has not yet been reported.

AIM OF THE STUDY

The present study was conducted to evaluate the exercise endurance promoting activities of fungal traditional Chinese medicine (FTCM) Cordyceps sinensis cultured whole mycelium (CS) and the underlying mechanisms.

MATERIALS AND METHODS

CS was orally supplemented (200mg/kg body weight/day) to rats for 15days with or without swimming exercise along with exercise and placebo groups.

RESULTS

Both CS supplementation and supplementation concurrent with exercise improved exercise endurance by 1.79- (P<0.05) and 2.9-fold (P<0.01) respectively as compared to placebo rats. CS supplementation concurrent with exercise also increased the swimming endurance by 1.32-fold (P<0.05) over the exercise group. To study the molecular mechanism of the observed effect, we measured the expression levels of endurance responsive skeletal muscle metabolic regulators AMPK, PGC-1α and PPAR-δ as well as endurance promoting and antioxidant genes like MCT1, MCT4, GLUT4, VEGF, NRF-2, SOD1 and TRX in red gastrocnemius muscle. Our results indicate that CS supplementation significantly upregulates the skeletal muscle metabolic regulators, angiogenesis, better glucose and lactate uptake both in exercised and non-exercised rats. We have also observed increased expression of oxidative stress responsive transcription factor NRF-2 and its downstream targets SOD1 and TRX by CS supplementation.

CONCLUSION

CS supplementation with or without exercise improves exercise endurance capacity by activating the skeletal muscle metabolic regulators and a coordinated antioxidant response. Consequently, CS can be used as a potent natural exercise mimetic.

HIF1A P582S gene association with endurance training responses in young women

Sequence variations in the gene encoding the hypoxia-inducible factor-1alpha, HIF1A, have been associated with physiologic function and could be associated with exercise responses. In the HIF1A P582S gene polymorphism (C1772T; rs 11549465 C/T), a single nucleotide transition from C → T alters the codon sequence from the usual amino acid; proline (C-allele), to serine (T-allele). This polymorphism was examined for association with endurance training responses in 58 untrained young women who completed a 6-week laboratory-based endurance training programme. Participant groups were defined as CC homozygotes versus carriers of a T-allele (CC vs. CT genotypes). Adaptations were examined at the systemic-level, by measuring [Formula: see text] and the molecular-level by measuring enzymes determined from vastus lateralis (n = 20): 3-hydroacyl-CoA-dehydrogenase (HAD), which regulates mitochondrial fatty acid oxidation; cytochrome C oxidase (COX-1), a marker of mitochondrial density; and phosphofructokinase (PFK), a marker of glycolytic capacity. CT genotypes showed 45% higher training-induced gains in [Formula: see text] compared with CC genotypes (P < 0.05). At the molecular level, CT increased the ratios PFK/HAD and PFK/COX-1 (47 and 3%, respectively), while in the CC genotypes these ratios were decreased (-26 and -54%, respectively). In conclusion, the T-allele of HIF1A P582S was associated with greater gains in [Formula: see text] following endurance training in young women. In a sub-group we also provide preliminary evidence of differential muscle metabolic adaptations between genotypes.

[Some potential candidate genes related to elite endurance diathesis]

Differences among individuals in exercise performance are multifactorial and determined by a range of environmental (physical training, nutrition, and technological aids) and genetic factors. So far, numerous gene polymorphisms involved in elite athletic capability have been studied. However, in recent years, the attempts to identify new genes or loci fell into a bottleneck and may limit the use of genetic information for talent search. We selected some potential endurance-related genes, reviewed their functions in physical performance, and studied on their polymorphisms. The results of this study will provide new ideas and references for future research.

Association between the angiotensin I-converting enzyme gene insertion/deletion polymorphism and endurance running speed in Japanese runners

We investigated the association between the angiotensin I-converting enzyme (ACE) gene insertion (I)/deletion (D) polymorphism and endurance running performance in Japanese elite runners, including several Olympic athletes. The frequency of the I/I genotype was not significantly higher and the frequency of the D/D genotype was not significantly lower in elite runners compared with non-athletes. However, the frequency of the I/D genotype tended to be lower in elite runners than in non-athletes. The best performance was significantly higher for runners with the D/D genotype than for those with the I/I genotype, and the average running speed was significantly higher for those with the combined D/D + I/D genotypes than for those with the I/I genotype. There were no I/I genotypes among the five fastest marathon runners. These results suggest that the D allele of the ACE gene I/D polymorphism is associated with a high level of human endurance.

Mitochondrial biogenesis related endurance genotype score and sports performance in athletes

We determined the probability of individuals having the 'optimal' mitochondrial biogenesis related endurance polygenic profile, and compared the endurance polygenic profile of Israeli (Caucasian) endurance athletes (n = 74), power athletes (n = 81), and non-athletes (n = 240). We computed a mitochondrial biogenesis related 'endurance genotype score' (EGS, scoring from 0 to 100) from the accumulated combination of six polymorphisms in the PPARGC1A-NRF-TFAM pathway. Some of the variant alleles of the polymorphisms studied were so infrequent, that the probability of possessing an 'optimal' EGS (= 100) was 0% in the entire study population. However, the EGS was significantly higher (P<0.001) in endurance athletes (38.9 ± 17.1) compared with controls (30.6 ± 12.4) or power athletes (29.0 ± 11.2). In summary, although the probability of an individual possessing a theoretically 'optimal' genetic background for endurance sports is very low, in general endurance athletes have a polygenic profile that is more suitable for mitochondrial biogenesis.

Training modalities: impact on endurance capacity

Endurance athletes demonstrate an exceptional resistance to fatigue when exercising at high intensity. Much research has been devoted to the contribution of aerobic capacity for the economy of endurance performance. Important aspects of the fine-tuning of metabolic processes and power output in the endurance athlete have been overlooked. This review addresses how training paradigms exploit bioenergetic pathways in recruited muscle groups to promote the endurance phenotype. A special focus is laid on the genome-mediated mechanisms that underlie the conditioning of fatigue resistance and aerobic performance by training macrocycles and complements. The available data on work-induced muscle plasticity implies that different biologic strategies are exploited in athletic and untrained populations to boost endurance capacity. Olympic champions are probably endowed with a unique constitution that renders the conditioning of endurance capacity for competition particularly efficient.

[Association of the mitochondrial transcription factor (TFAM) gene polymorphism with physical performance of athletes]

The aim of the study was to investigate allelic distribution of the mitochondrial transcription factor gene (TFAM) Ser12Thr polymorphism in athletes (n = 1537) and controls (n = 1113), and to find interrelation between genotypes and aerobic capacity in rowers (n = 90). Genotyping was performed by restriction fragment length polymorphism analysis. Aerobic capacity (maximal oxygen consumption (VO2max) and maximal power production capacity (Wmax)) was determined using an incremental test to exhaustion by rower ergometer. The frequency of TFAM 12Thr allele was significantly higher in endurance-oriented athletes (n = 588) than in controls (14.0% vs. 9.1%; p <0.0001), and increased with the growth of skills. Furthermore, TFAM 12Thr allele was associated with high values of aerobic performance (when Wmax and VO2max were measured). Thus, TFAM gene Ser12Thr polymorphism is associated with physical performance of athletes.

The electrocardiographic abnormalities in highly trained athletes compared to the genetic study related to causes of unexpected sudden cardiac death

BACKGROUND

Electrocardiograms in elite endurance athletes sometimes show bizarre patterns suggestive of inherited channelopathies (Brugada syndrome, long QTc, catecholaminergic polymorphic ventricular tachycardia) and cardiomyopathies (arrhythmogenic right ventricular cardiomyopathy, hypertrophic cardiomyopathy) responsible for unexpected sudden cardiac death. Among other methods, genetic analyses are required for correct diagnosis.

OBJECTIVE

To correlate 12-lead electrocardiographic patterns suggestive of inherited channelopathies and cardiomyopathies to specific genetic analyses.

DESIGN

Prospective study (2004-2007) of screening 12-lead ECG tracings in standard position and higher intercostal spaces V1 to V3 precordial leads, performed in athletes and normal sedentary subjects aged match. Genetic analyses of subjects with ECG abnormalities suggested inherited channelopathies and cardiomyopathies.

SETTING

All cardiologic exams and electrocardiograms were performed at "Prof. Dr. C.C. Iliescu" National Institute of Cardiovascular Diseases (Bucharest, Romania). The genetic studies were done at "Mina Minovici" National Institute of Forensic Medicine (Bucharest, Romania).

PARTICIPANTS

347 elite endurance athletes (seniors--190, juniors--157), mean age of 20; 200 subjects mean age of 21, belonging to the control group of 505 normal sedentary population.

RESULTS

Seniors. RSR' (V1 to V3) pattern, in 45 cases (23.68%), 5 of them with questionable Brugada sign (elevated J wave and "coved" ST segment, < 2 mm in one lead, V1. Typically, Brugada 1 sign was found in one case (0.52%) with no SCN5A abnormalities. One athlete (0.52%) had normal ECG and exon1 SCN5A duplication. MRI confirmed three arrhythmic right ventricular cardiomypathy epsilon waves (1.57%), in one case. ST-segment elevation myocardial injury like in V1-V3 precordial leads in 34 athletes (17.89%). Genetic analyses-no gene mutations. Juniors. Upright J wave was found in 43 cases (27.38%). Convex ST segment elevation in V1-V3/V4, in 39 cases (24.84%). Bifid T wave with two distinct peaks was found in 39 cases (24.84%), 5 of them with mild prolonged QTc (0.48"-0.56") and KCN genes mutations. Nine (5.73%) of the elevated ST segment juniors had questionable Brugada sign, two of which with KCN (n=1) and SCN5A (n=1) gene mutations. Ajmaline provocative test was negative in 4 and was refused by 5 subjects.

CONCLUSION

Bizarre QRS, ST-T patterns suggestive of abnormal impulse conduction in the right ventricle, including the right outflow tract, associated with prolonged QTc interval in some cases were observed in highly trained endurance athletes. The genetic analyses, negative in most athletes, identified surprising mutations in SCN5A and KCN genes in some cases.

Genes, athlete status and training -- An overview

Significant data confirming the influence of genes on human physical performance and elite athlete status have been accumulated in recent years. Research of gene variants that may explain differences in physical capabilities and training-induced effects between subjects is widely carried out. In this review, the findings of genetic studies investigating DNA polymorphisms and their association with elite athlete status and training responses are reported. A literature search revealed that at least 36 genetic markers (located within 20 autosomal genes, mitochondrial DNA and Y-chromosome) are linked to elite athlete status and 39 genetic markers (located within 19 genes and mitochondrial DNA) may explain, in part, an interindividual variability of physical performance characteristics in response to endurance/strength training. Although more replication studies are needed, the preliminary data suggest an opportunity to use some of these genetic markers in an individually tailored prescription of lifestyle/exercise for health and sports performance.

Adipose triacylglycerol lipase deletion alters whole body energy metabolism and impairs exercise performance in mice

Adipose triacylglycerol lipase (ATGL) and hormone-sensitive lipase (HSL) are essential for efficient lipolysis in adipose tissue and skeletal muscle. Herein, we utilized whole body knockout mice to address the importance of ATGL and HSL for metabolic function and exercise performance. ATGL deletion severely disrupts whole-body substrate partitioning at rest; reducing plasma free fatty acid (FFA) availability (WT: 0.49 +/- 0.06 vs. ATGL(-/-) 0.34 +/- 0.03 mM), which in turn enhances carbohydrate oxidation during fasting (mean RER, WT: 0.86 +/- 0.02, ATGL(-/-) 0.90 +/- 0.01) and is associated with depleted muscle and liver glycogen stores. While plasma FFA was modestly reduced (23%) and whole body carbohydrate metabolism increased in HSL(-/-) mice, resting glycogen storage was not compromised. Studies in isolated muscles revealed that the capacity of ATGL and HSL(-/-) muscle to transport exogenous fatty acids is not compromised and the capacity to oxidize fatty acids is actually increased (3.7- and 1.3-fold above WT for ATGL and HSL). The exercise-induced increase in plasma FFA and glycerol was blunted with ATGL or HSL deletion, demonstrating an impaired capacity for exercise-induced lipolysis in these mice. Carbohydrate oxidation was increased concomitantly during exercise in ATGL(-/-) and HSL(-/-) mice, resulting in more muscle and liver glycogen depletion. Maximal running velocity and endurance capacity were reduced by 42% and 46% in ATGL(-/-) mice, but not in HSL(-/-) mice. The reduction in performance in ATGL(-/-) mice was not due to defective muscle contractile performance. These results demonstrate an essential role for both ATGL and HSL in maintaining adequate FFA supply to sustain normal substrate metabolism at rest and during exercise.

Endurance capacity, not body size, determines physical activity levels: role of skeletal muscle PEPCK

Some people remain lean despite pressure to gain weight. Lean people tend to have high daily activity levels, but the source of this increased activity is unknown. We found that leanness cannot be accounted for by increased weight-corrected food intake in two different types of lean rats. As previously reported in lean people, we found that lean rats had higher daily activity levels; lean rats also expended more energy. These lean rats were developed through artificial selection for high aerobic endurance capacity. To test whether our findings extended to a human population, we measured endurance capacity using a VO_2max treadmill test and daily activity in a group of non-exercising individuals. Similar to lean rats selectively bred for endurance capacity, our study revealed that people with higher VO_2max also spent more time active throughout the day. Hence, endurance capacity may be the trait that underlies both physical activity levels and leanness. We identified one potential mechanism for the lean, active phenotype in rats, namely high levels of skeletal muscle PEPCK. Therefore, the lean phenotype is characterized by high endurance capacity and high activity and may stem from altered skeletal muscle energetics.

Endurance swimming stimulates transepithelial calcium transport and alters the expression of genes related to calcium absorption in the intestine of rats

Endurance impact exercise, e.g., running, is known to enhance the intestinal calcium absorption. However, nonimpact exercise, e.g., swimming, is more appropriate for osteoporotic patients with cardiovascular diseases or disorders of bone and joint, but the effect of swimming on the intestinal calcium transport was unknown. This study, therefore, aimed to investigate the transepithelial calcium transport and the expression of related genes in the intestine of rats trained to swim nonstop 1 h/day, 5 days/wk for 2 wk. We found that endurance swimming stimulated calcium transport in the duodenum, proximal jejunum, and cecum, while decreasing that in the proximal colon. Swimming affected neither the transepithelial potential difference nor resistance. As demonstrated by real-time PCR, the small intestine, especially the duodenum, responded to swimming by upregulating a number of genes related to the transcellular calcium transport, i.e., TRPV5, TRPV6, calbindin-D9k, PMCA1b, and NCX1, and the paracellular calcium transport, i.e., ZO-1, ZO-2, ZO-3, cingulin, occludin, and claudins, as well as nuclear receptor of 1,25(OH)2D3. In contrast, swimming downregulated those genes in the colon. Microarray analysis showed that swimming also altered the expression of duodenal genes related to the transport of several ions and nutrients, e.g., Na+, K+, Cl-, glucose, and amino acids. In conclusion, endurance swimming enhanced intestinal calcium absorption, in part, by upregulating the calcium transporter genes. The present microarray study also provided relevant information for further investigations into the intestinal nutrient and electrolyte transport during nonimpact exercise.

Clinical use of creatine in neuromuscular and neurometabolic disorders

Many of the neuromuscular (e.g., muscular dystrophy) and neurometabolic (e.g., mitochondrial cytopathies) disorders share similar final common pathways of cellular dysfunction that may be favorably influenced by creatine monohydrate (CrM) supplementation. Studies using the mdx model of Duchenne muscular dystrophy have found evidence of enhanced mitochondrial function, reduced intra-cellular calcium and improved performance with CrM supplementation. Clinical trials in patients with Duchenne and Becker's muscular dystrophy have shown improved function, fat-free mass, and some evidence of improved bone health with CrM supplementation. In contrast, the improvements in function in myotonic dystrophy and inherited neuropathies (e.g., Charcot-Marie-Tooth) have not been significant. Some studies in patients with mitochondrial cytopathies have shown improved muscle endurance and body composition, yet other studies did not find significant improvements in patients with mitochondrial cytopathy. Lower-dose CrM supplementation in patients with McArdle's disease (myophosphorylase deficiency) improved exercise capacity, yet higher doses actually showed some indication of worsened function. Based upon known cellular pathologies, there are potential benefits from CrM supplementation in patients with steroid myopathy, inflammatory myopathy, myoadenylate deaminase deficiency, and fatty acid oxidation defects. Larger randomized control trials (RCT) using homogeneous patient groups and objective and clinically relevant outcome variables are needed to determine whether creatine supplementation will be of therapeutic benefit to patients with neuromuscular or neurometabolic disorders. Given the relatively low prevalence of some of the neuromuscular and neurometabolic disorders, it will be necessary to use surrogate markers of potential clinical efficacy including markers of oxidative stress, cellular energy charge, and gene expression patterns.

[Research on the relation between ACE gene I/D polymorphisms and sensitivity to endurance training of Han nationality male]

AIM

In order to seek the marks of the genes, the relation between the influence of endurance training on aerobic ability and ACE Gene I/D Polymorphisms were studied.

METHODS

102 army recruits of Han nationality from North China for an 18 week en durance training of 5000m distance. Their VO2(max), VT and the left ventricular structure and function were measured before and after the training. We also tested their ACE Gene I/D Polymorphisms with PCR-AFLP method.

RESULTS

The compliance of VO2(max), VT and left ventricular structure and function had improved after the training; the deltaVO2(max) of ID and II type was obviously higher than that of DD type (P < 0.05); there was obviously diference of deltaVO2(VT) in different ACE genotype (P < 0.05), the deltaVO2(VT) of type II was obviously higher than that of DD type (P < 0.05).

CONCLUSION

I allele has obviously hereditary advantage on the sensitivity to aerobic training in VO2(max) and VT, and type II has relation on the sensitivity to aerobic training in VT; there is no relation between I/D polymorphism and the sensitivity to aerobic training on the structure and function of left ventricle.

[The influence of calcineurin gene polymorphism on morphofunctional characteristics of cardiovascular system of athletes]

The aim of the study was to investigate allelic distribution of calcineurin gene (CNB; 5I/5D polymorphism) in athletes of cyclic sports (n = 673) and controls (n = 1073), and to find interrelation between genotypes and risk of left ventricular hypertrophy and physical performance of athletes. Genotyping was performed by restriction fragment length polymorphism. Echocardiography was performed by ultrasound scanner Aloka-3500. Physiological parameters were evaluated by spiroergometry using MetaMax 3B Gas Analyzer. The frequency of CNB D allele was significantly lo- wer in athletes than in controls (5.5 vs. 8.8 %; p = 0.0005), and decreased with the growth of skills. We found that CNB D allele was associated with increased left ventricular mass index and low values of physical performance (when maximal power production capacity and maximal oxygen consumption were measured). Thus, CNB gene 5I/5D polymorphism is associated with the risk of left ventricular hypertrophy and physical performance of athletes.

Body fat and mobility are explained by common genetic and environmental influences in older women

In older adults, mobility limitations often coexist with overweight or obesity, suggesting that similar factors may underlie both traits. This study examined the extent to which genetic and environmental influences explain the association between adiposity and mobility in older women. Body fat percentage (bioimpedance test), walking speed over 10 m, and distance walked in a 6-min test were evaluated in 92 monozygotic (MZ) and 104 dizygotic (DZ) pairs of twin sisters reared together, aged 63-76 years. Genetic and environmental influences on each trait were estimated using age-adjusted multivariate genetic modeling. The analyses showed that the means (and s.d.) for body fat percentage, walking speed, and walking endurance were 33.2+/-7.3%, 1.7+/-0.3 m/s and 529.7+/-75.4 m, respectively. The phenotypic correlation between adiposity and walking speed was -0.32 and between adiposity and endurance it was -0.33. Genetic influences explained 80% of the association between adiposity and speed, and 65% of adiposity and walking endurance. Cross-trait genetic influences accounted for 12% of the variability in adiposity, 56% in walking speed, and 34% in endurance. Trait-specific genetic influences were also detected for adiposity (54%) and walking endurance (13%), but not speed. In conclusion, among community-living older women, an inverse association was found between adiposity and mobility that was mostly due to the effect of shared genes. This result suggests that the identification of genetic variants for body fat metabolism may also provide understanding of the development of mobility limitations in older women.

Relationship between TFAM Gene Polymorphisms and Endurance Capacity in Response to Training

The aim of this study was to explore whether polymorphisms in mitochondrial transcription factor A ( TFAM) gene are associated with endurance capacity in a pretraining state (baseline) and/or in response to a supervised 18-wk endurance training (changes) in 102 young Chinese males (nonathletes). Phenotypes measured were running economy (RE) and V(.)O (2max). Genomic DNA was extracted from white blood cells and the genotypes were analyzed by PCR-RFLP in single nucleotide polymorphisms (SNP) rs1937, rs2306604 and rs1049432. Genotype distributions were in Hardy-Weinberg equilibrium at three loci (p > 0.05). When the three polymorphisms were considered together, three haplotypes were estimated, i.e., G (rs1937)-A (rs2306604)-G (rs1049432) (49 %), G (rs1937)-G (rs2306604)-G (rs1049432) (33 %) and C (rs1937)-G (rs2306604)-T (rs1049432) (18 %). SNPrs1937 and rs1049432 achieved near complete linkage disequilibrium (LD) (D' = 1 and r (2) = 0.903). We found no significant differences in baseline levels of V(.)O (2max) and RE between TFAM genotypes or haplotypes. Similarly, we found no differences for the training-induced changes of both variables. It was concluded that the three polymorphisms in TFAM gene rs1937, rs2306604 and rs1049432 do not predict endurance capacity/trainability, at least in Chinese males.