Modulations of corticospinal excitability following rapid ankle dorsiflexion in skill- and endurance-trained athletes.

PURPOSE: Long-term sports training, such as skill and endurance training, leads to specific neuroplasticity. However, it remains unclear if muscle stretch-induced proprioceptive feedback influences corticospinal facilitation/inhibition differently between skill- and endurance-trained athletes. This study investigated modulation of corticospinal excitability following rapid ankle dorsiflexion between well-trained skill and endurance athletes. METHODS: Ten skill- and ten endurance-trained athletes participated in the study. Corticospinal excitability was tested by single- and paired-pulse transcranial magnetic stimulations (TMS) at three different latencies following passive rapid ankle dorsiflexion. Motor evoked potential (MEP), short-latency intracortical inhibition (SICI), intracortical facilitation (ICF), and long-latency intracortical inhibition (LICI) were recorded by surface electromyography from the soleus muscle. RESULTS: Compared to immediately before ankle dorsiflexion (Onset), TMS induced significantly greater MEPs during the supraspinal reaction period (~ 120 ms after short-latency reflex, SLR) in the skill group only (from 1.7 ± 1.0 to 2.7 ± 1.8%M-max, P = 0.005) despite both conditions being passive. ICF was significantly greater over all latencies in skill than endurance athletes (F (3, 45) = 4.64, P = 0.007), although no between-group differences for stimulations at specific latencies (e.g., at SLR) were observed. CONCLUSION: The skill group showed higher corticospinal excitability during the supraspinal reaction phase, which may indicate a "priming" of corticospinal excitability following rapid ankle dorsiflexion for a supraspinal reaction post-stretch, which appears absent in endurance-trained athletes.

Physical loading in professional soccer players: Implications for contemporary guidelines to encompass carbohydrate periodization.

Despite more than four decades of research examining the physical demands of match-play, quantification of the customary training loads of adult male professional soccer players is comparatively recent. The training loads experienced by players during weekly micro-cycles are influenced by phase of season, player position, frequency of games, player starting status, player-specific training goals and club coaching philosophy. From a macronutrient perspective, the periodization of physical loading within (i.e., match versus training days) and between contrasting micro-cycles (e.g., 1, 2 or 3 games per week schedules) has implications for daily carbohydrate (CHO) requirements. Indeed, aside from the well-recognised role of muscle glycogen as the predominant energy source during match-play, it is now recognised that the glycogen granule may exert regulatory roles in activating or attenuating the molecular machinery that modulate skeletal muscle adaptations to training. With this in mind, the concept of CHO periodization is gaining in popularity, whereby CHO intake is adjusted day-by-day and meal-by-meal according to the fuelling demands and specific goals of the upcoming session. On this basis, the present paper provides a contemporary overview and theoretical framework for which to periodize CHO availability for the professional soccer player according to the "fuel for the work" paradigm.

Upper-Extremity Perceptual-Motor Training Improves Whole-Body Reactive Agility Among Elite Athletes With History of Sport-Related Concussion.

CONTEXT: Sport-related concussion (SRC) elevates risk for subsequent injury, which may relate to impaired perceptual-motor processes that are potentially modifiable. OBJECTIVE: To assess a possible upper-extremity (UE) training effect on whole-body (WB) reactive agility performance among elite athletes with history of SRC (HxSRC) and without such history of SRC. DESIGN: Cohort study. SETTING: Residential training center. PARTICIPANTS: Elite athletes (12 males and 8 females), including 10 HxSRC and 10 without such history of SRC. INTERVENTION: One-minute training sessions completed 2 to 3 times per week over a 3-week period involved verbal identification of center arrow direction for 10 incongruent and 10 congruent flanker test trials with simultaneous reaching responses to deactivate illuminated buttons. MAIN OUTCOME MEASURES: Pretraining and posttraining assessments of UE and WB reactive responses included flanker test conflict effect (incongruent minus congruent reaction time) and WB lateral average asymmetry derived from reaction time, speed, acceleration, and deceleration in opposite directions. Discrimination was assessed by receiver operating characteristic analysis, and training effect was assessed by repeated-measures analysis of variance. RESULTS: Pretraining discrimination between HxSRC and without such history of SRC was greatest for conflict effect ≥80 milliseconds and WB lateral average asymmetry ≥18%. Each athlete completed 6 training sessions, which improved UE mean reaction time from 767 to 646 milliseconds (P < .001) and reduced mean conflict effect from 96 to 53 milliseconds (P = .039). A significant group × trial interaction was evident for WB lateral average asymmetry (P = .004), which was reduced from 24.3% to 12.5% among those with HxSRC. CONCLUSIONS: Suboptimal perceptual-motor performance may represent a subtle long-term effect of concussion that is modifiable through UE training, which appears to improve WB reactive capabilities.

Exercise training during chemotherapy preserves skeletal muscle fiber area, capillarization, and mitochondrial content in patients with breast cancer.

Exercise has been suggested to ameliorate the detrimental effects of chemotherapy on skeletal muscle. The aim of this study was to compare the effects of different exercise regimens with usual care on skeletal muscle morphology and mitochondrial markers in patients being treated with chemotherapy for breast cancer. Specifically, we compared moderate-intensity aerobic training combined with high-intensity interval training (AT-HIIT) and resistance training combined with high-intensity interval training (RT-HIIT) with usual care (UC). Resting skeletal muscle biopsies were obtained pre- and postintervention from 23 randomly selected women from the OptiTrain breast cancer trial who underwent RT-HIIT, AT-HIIT, or UC for 16 wk. Over the intervention, citrate synthase activity, muscle fiber cross-sectional area, capillaries per fiber, and myosin heavy chain isoform type I were reduced in UC, whereas RT-HIIT and AT-HIIT were able to counteract these declines. AT-HIIT promoted up-regulation of the electron transport chain protein levels vs. UC. RT-HIIT favored satellite cell count vs. UC and AT-HIIT. There was a significant association between change in citrate synthase activity and self-reported fatigue. AT-HIIT and RT-HIIT maintained or improved markers of skeletal muscle function compared with the declines found in the UC group, indicating a sustained trainability in addition to the preservation of skeletal muscle structural and metabolic characteristics during chemotherapy. These findings highlight the importance of supervised exercise programs for patients with breast cancer during chemotherapy.-Mijwel, S., Cardinale, D. A., Norrbom, J., Chapman, M., Ivarsson, N., Wengström, Y., Sundberg, C. J., Rundqvist, H. Exercise training during chemotherapy preserves skeletal muscle fiber area, capillarization, and mitochondrial content in patients with breast cancer.

The use of the SLC16A1 gene as a potential marker to predict race performance in Arabian horses.

BACKGROUND: Arabian horses are commonly believed to be one of the oldest and the most popular horse breeds in the world, characterized by favourable stamina traits and exercise phenotypes. During intensive training, the rates of lactate production and utilization are critical to avoid muscle fatigue and a decrease in exercise performance. The key factor determining transmembrane lactate transport is the monocarboxylate transporter 1 protein coded for by the SLC16A1 gene. The aim of the present research was to identify polymorphisms in the coding sequence and UTRs in the equine SLC16A1 gene and to evaluate their potential association with race performance traits in Arabian horses. Based on RNA-seq data, SNPs were identified and genotyped using PCR-RFLP or PCR-HRM methods in 254 Arabian horses that competed in flat races. An association analysis between polymorphisms and racing results was performed. RESULTS: Novel polymorphisms in the equine SLC16A1 locus have been identified (missense and 5'UTR variants: g.55601543C > T and g.55589063 T > G). Analysis showed a significant association between the 5'UTR polymorphism and several racing results as follows: the possibility of winning first or second place, the number of races in which horses started and total financial benefits. The analysis also showed differences in genotype distribution depending on race distance. In the studied population, the shorter distance races were only won by TT horses. The GG and TG horses took first and second places in middle- and long-distance races, and the percentage of winning heterozygotes increased from 19.5 to 27% at the middle and long distances, respectively. The p.Val432Ile (g.55601543C > T) polymorphism was not significantly related to the analysed racing results. CONCLUSION: Our results showed that g.55589063 T > G polymorphism affected the possibility of winning first or second place and of competing in more races. The different distribution of genotypes depending on race distance indicated the possibility of using a SNP in the SLC16A1 gene as a marker to predict the best race distance for a horse. The presented results provide a basis for further research to validate the use of the SLC16A1 gene as a potential marker associated with racing performance.

Distinct Effects of Repeated-Sprint Training in Normobaric Hypoxia and ß-Alanine Supplementation.

OBJECTIVE: The present study evaluated the effects of repeated-sprint training in normobaric hypoxia and ß-alanine supplementation (BA) on aerobic and anaerobic performance in recreationally active men. METHODS: Participants were randomly assigned to one of the following groups: normoxia/ß-alanine (NB, n = 11), normoxia/placebo (NP, n = 8), normobaric hypoxia/ß-alanine (HB, n = 10) and normobaric hypoxia/placebo (HP, n = 9). All participants completed 8 training sessions over 4 weeks on a cycle ergometer either in normobaric hypoxia (oxygen fraction: FiO2 = 14.2%) or normoxia (FiO2 = 20.9%). Participants were instructed to consume a daily dosage of 6.4 g of BA or placebo. Changes in performance in a graded exercise test, repeated-sprint test (RST), and 3-minute all-out test (3MT) were examined before and after training and supplementation. RESULTS: No between-group differences were observed for training volume or supplementation compliance. Anthropometric and hematological measures remained unchanged before and after intervention in all groups. A main effect of training condition was shown for oxygen consumption and power output at respiratory compensation point, average power output during the last sprint of the RST, heart rate recovery following the RST, and total work during the 3MT. These measures in the normobaric hypoxia groups were significantly (p < 0.05) higher than the normoxia groups, except for the heart rate recovery following the RST. A main effect of supplement was detected in anaerobic working capacity, with postintervention values in the BA groups being significantly (p < 0.05) higher than the placebo groups. CONCLUSIONS: Repeated-sprint training in hypoxia improved aerobic performance, exercise tolerance, cardiovascular recovery, and overall working capacity, while BA maintained the anaerobic working capacity. However, BA did not provide additional benefits with respect to attenuating fatigue or enhancing repeated-sprint performance.

Sustained high levels of physical activity lead to improved performance among "Race Across the USA" athletes.

OBJECTIVE: To investigate physiological and performance adaptations associated with extremely high daily sustained physical activity levels, we followed six runners participating in the 2015 Race Across the USA. Participants completed over 42.2 km a day for 140 days, covering nearly 5,000 km. This analysis examines the improvement in running speed and potential adaptation in mean submaximal heart rate (SHR) throughout the race. METHODS: Data were collected during three 1-week long periods corresponding to the race beginning, middle, and end and included heart rates (HRs), body mass, running distances and speeds. HR data were collected using ActiTrainer HR monitors. Running speeds and distances were also recorded throughout the entire race. RESULTS: Athletes ran significantly faster as the race progressed (p < .001), reducing their mean marathon time by over 63 min. Observed mean SHR during the middle of the race was significantly lower than at the beginning (p = .003); however, there was no significant difference between mean SHR at the middle and end of the race (p = .998). CONCLUSION: These results indicate an early training effect in SHR during the first half of the race, which suggests that other physiological and biomechanical mechanisms were responsible for the continued improvement in running speed and adaptation to the high levels of sustained physical activity.

Improvement in muscle strength with low-load isotonic training depends on fascicle length but not joint angle.

INTRODUCTION: In this study we investigate whether low-load isotonic training will elicit greater improvement in muscle strength at the same fascicle length, rather than at the same joint angle. METHODS: Sixteen healthy men (24.1 ± 2.5 years of age) were randomly divided into intervention and control groups. Pre- and posttraining maximum isometric and isokinetic strengths and fascicle lengths of the medial gastrocnemius muscle were measured. Isotonic resistance training at 15 ° to 30 ° ankle plantarflexion at low intensity was conducted for 4 weeks. RESULTS: The maximum isometric and isokinetic strength of the intervention group increased significantly only at 15 ° dorsiflexion and 8 ° to 12 ° dorsiflexion. Fascicle length during maximum voluntary contraction at 15 ° dorsiflexion to 0 ° was similar to fascicle length under training conditions. DISCUSSION: It is possible that the improvement in muscle strength with low-load training depends on fascicle length rather than joint angle. Muscle Nerve 57: 83-89, 2018.

Increasing skeletal muscle carnitine availability does not alter the adaptations to high-intensity interval training.

Increasing skeletal muscle carnitine availability alters muscle metabolism during steady-state exercise in healthy humans. We investigated whether elevating muscle carnitine, and thereby the acetyl-group buffering capacity, altered the metabolic and physiological adaptations to 24 weeks of high-intensity interval training (HIIT) at 100% maximal exercise capacity (Wattmax ). Twenty-one healthy male volunteers (age 23±2 years; BMI 24.2±1.1 kg/m2 ) performed 2 × 3 minute bouts of cycling exercise at 100% Wattmax , separated by 5 minutes of rest. Fourteen volunteers repeated this protocol following 24 weeks of HIIT and twice-daily consumption of 80 g carbohydrate (CON) or 3 g l-carnitine+carbohydrate (CARN). Before HIIT, muscle phosphocreatine (PCr) degradation (P<.0001), glycogenolysis (P<.0005), PDC activation (P<.05), and acetylcarnitine (P<.005) were 2.3-, 2.1-, 1.5-, and 1.5-fold greater, respectively, in exercise bout two compared to bout 1, while lactate accumulation tended (P<.07) to be 1.5-fold greater. Following HIIT, muscle free carnitine was 30% greater in CARN vs CON at rest and remained 40% elevated prior to the start of bout 2 (P<.05). Following bout 2, free carnitine content, PCr degradation, glycogenolysis, lactate accumulation, and PDC activation were all similar between CON and CARN, albeit markedly lower than before HIIT. VO2max , Wattmax , and work output were similarly increased in CON and CARN, by 9, 15, and 23% (P<.001). In summary, increased reliance on non-mitochondrial ATP resynthesis during a second bout of intense exercise is accompanied by increased carnitine acetylation. Augmenting muscle carnitine during 24 weeks of HIIT did not alter this, nor did it enhance muscle metabolic adaptations or performance gains beyond those with HIIT alone.

Effects of skeletal muscle energy availability on protein turnover responses to exercise.

Skeletal muscle adaptation to exercise training is a consequence of repeated contraction-induced increases in gene expression that lead to the accumulation of functional proteins whose role is to blunt the homeostatic perturbations generated by escalations in energetic demand and substrate turnover. The development of a specific 'exercise phenotype' is the result of new, augmented steady-state mRNA and protein levels that stem from the training stimulus (i.e. endurance or resistance based). Maintaining appropriate skeletal muscle integrity to meet the demands of training (i.e. increases in myofibrillar and/or mitochondrial protein) is regulated by cyclic phases of synthesis and breakdown, the rate and turnover largely determined by the protein's half-life. Cross-talk among several intracellular systems regulating protein synthesis, breakdown and folding is required to ensure protein equilibrium is maintained. These pathways include both proteasomal and lysosomal degradation systems (ubiquitin-mediated and autophagy, respectively) and the protein translational and folding machinery. The activities of these cellular pathways are bioenergetically expensive and are modified by intracellular energy availability (i.e. macronutrient intake) and the 'training impulse' (i.e. summation of the volume, intensity and frequency). As such, exercise-nutrient interactions can modulate signal transduction cascades that converge on these protein regulatory systems, especially in the early post-exercise recovery period. This review focuses on the regulation of muscle protein synthetic response-adaptation processes to divergent exercise stimuli and how intracellular energy availability interacts with contractile activity to impact on muscle remodelling.

The AGT Gene M235T Polymorphism and Response of Power-Related Variables to Aerobic Training.

The C allele of the M235T (rs699) polymorphism of the AGT gene correlates with higher levels of angiotensin II and has been associated with power and strength sport performance. The aim of the study was to investigate whether or not selected power-related variables and their response to a 12-week program of aerobic dance training are modulated by the AGT M235T genotype in healthy participants. Two hundred and one Polish Caucasian women aged 21 ± 1 years met the inclusion criteria and were included in the study. All women completed a 12-week program of low and high impact aerobics. Wingate peak power and total work capacity, 5 m, 10 m, and 30 m running times and jump height and jump power were determined before and after the training programme. All power-related variables improved significantly in response to aerobic dance training. We found a significant association between the M235T polymorphism and jump-based variables (squat jump (SJ) height, p = 0.005; SJ power, p = 0.015; countermovement jump height, p = 0.025; average of 10 countermovement jumps with arm swing (ACMJ) height, p = 0.001; ACMJ power, p = 0.035). Specifically, greater improvements were observed in the C allele carriers in comparison with TT homozygotes. In conclusion, aerobic dance, one of the most commonly practiced adult fitness activities in the world, provides sufficient training stimuli for augmenting the explosive strength necessary to increase vertical jump performance. The AGT gene M235T polymorphism seems to be not only a candidate gene variant for power/strength related phenotypes, but also a genetic marker for predicting response to training.

Ramping up the signal: promoting endurance training adaptation in skeletal muscle by nutritional manipulation.

Mitochondrial biogenesis in skeletal muscle results from the cumulative effect of transient increases in mRNA transcripts encoding mitochondrial proteins in response to repeated exercise sessions. This process requires the coordinated expression of both nuclear and mitochondrial (mt) DNA genomes and is regulated, for the most part, by the peroxisome proliferator-activated receptor γ coactivator 1α. Several other exercise-inducible proteins also play important roles in promoting an endurance phenotype, including AMP-activated protein kinase, p38 mitogen-activated protein kinase and tumour suppressor protein p53. Commencing endurance-based exercise with low muscle glycogen availability results in greater activation of many of these signalling proteins compared with when the same exercise is undertaken with normal glycogen concentration, suggesting that nutrient availability is a potent signal that can modulate the acute cellular responses to a single bout of exercise. When exercise sessions are repeated in the face of low glycogen availability (i.e. chronic training), the phenotypic adaptations resulting from such interventions are also augmented.

Molecular aspects of the exercise response and training adaptation in skeletal muscle.

Skeletal muscle plasticity enables an enormous potential to adapt to various internal and external stimuli and perturbations. Most notably, changes in contractile activity evoke a massive remodeling of biochemical, metabolic and force-generating properties. In recent years, a large number of signals, sensors, regulators and effectors have been implicated in these adaptive processes. Nevertheless, our understanding of the molecular underpinnings of training adaptation remains rudimentary. Specifically, the mechanisms that underlie signal integration, output coordination, functional redundancy and other complex traits of muscle adaptation are unknown. In fact, it is even unclear how stimulus-dependent specification is brought about in endurance or resistance exercise. In this review, we will provide an overview on the events that describe the acute perturbations in single endurance and resistance exercise bouts. Furthermore, we will provide insights into the molecular principles of long-term training adaptation. Finally, current gaps in knowledge will be identified, and strategies for a multi-omic and -cellular analyses of the molecular mechanisms of skeletal muscle plasticity that are engaged in individual, acute exercise bouts and chronic training adaptation discussed.

Investigation of motor unit behavior in exercise and sports physiology: challenges and perspectives.

Several methods are in use to record and analyze neuronal activation, each with specific advantages and challenges. New developments like the decomposition of high-density surface electromyography (HDsEMG) have enabled novel insights into discharge characteristics noninvasively in laboratory settings but face certain challenges to be applied in sports physiology in a broader scope. Several challenges can be accounted for by methodological considerations, others require further technological developments to allow this technology to be used in more applied settings. This paper aims to describe the developments of surface electromyography and identify the challenges and perspectives of HDsEMG in the context of an application in sports physiology. We further discuss methodological possibilities to overcome some of the challenges to investigate specific research questions and identify areas that require further advancements.

Relationships between endurance exercise training-induced muscle fiber-type shifting and autophagy in slow- and fast-twitch skeletal muscles of mice.

PURPOSE: Endurance exercise induces muscle fiber-type shifting and autophagy; however, the potential role of autophagy in muscle fiber-type transformation remains unclear. This study examined the relationship between muscle fiber-type shifting and autophagy in the soleus (SOL) and extensor digitorum longus (EDL) muscles, which are metabolically discrete muscles. METHODS: Male C57BL/6J mice were randomly assigned to sedentary control (CON) and exercise (EXE) groups. After 1 week of acclimation to treadmill running, the mice in the EXE group ran at 12-15 m/min, 60 min/day, 5 days/week for 6 weeks. All mice were sacrificed 90 min after the last exercise session, and the targeted tissues were rapidly dissected. The right side of the tissues was used for western blot analysis, whereas the left side was subjected to immunohistochemical analysis. RESULTS: Endurance exercise resulted in muscle fiber-type shifting (from type IIa to type I) and autophagy (an increase in LC3-II) in the SOL muscle. However, muscle fiber-type transformation and autophagy were not correlated in the SOL and EDL muscles. Interestingly, in contrast to the canonical autophagy signaling pathways, our study showed that exercise-induced autophagy concurs with enhanced anabolic (increased p-AKTSer473/AKT and p-mTOR/mTORSer2448 ratios) and suppressed catabolic (reduced p-AMPKThr172/AMPK ratio) states. CONCLUSION: Our findings demonstrate that chronic endurance exercise-induced muscle fiber-type transformation and autophagy occur in a muscle-specific manner (e.g., SOL). More importantly, our study suggests that endurance training-induced SOL muscle fiber-type transition may underlie metabolic modulations caused by the AMPK and AKT/mTOR signaling pathways rather than autophagy.

Appropriate exercise prescription in primary and secondary prevention of cardiovascular disease: why this skill remains to be improved among clinicians and healthcare professionals. A call for action from the EXPERT Network†.

In Europe alone, on a yearly basis, millions of people need an appropriate exercise prescription to prevent the occurrence or progression of cardiovascular disease (CVD). A general exercise recommendation can be provided to these individuals (at least 150 min of moderate-intensity endurance exercise, spread over 3-5 days/week, complemented by dynamic moderate-intensity resistance exercise 2 days/week). However, recent evidence shows that this one size does not fit all and that individual adjustments should be made according to the patient's underlying disease(s), risk profile, and individual needs, to maximize the clinical benefits of exercise. In this paper, we (i) argue that this general exercise prescription simply provided to all patients with CVD, or elevated risk for CVD, is insufficient for optimal CVD prevention, and (ii) show that clinicians and healthcare professionals perform heterogeneously when asked to adjust exercise characteristics (e.g. intensity, volume, and type) according to the patient's condition, thereby leading to suboptimal CVD risk factor control. Since exercise training is a class 1A intervention in the primary and secondary prevention of CVD, the awareness of the need to improve exercise prescription has to be raised among clinicians and healthcare professionals if optimized prevention of CVD is ambitioned.

Effects of high-resistance wheel running on hallmarks of endurance and resistance training adaptations in mice.

Exercise effectively promotes and preserves cardiorespiratory, neuromuscular, metabolic, and cognitive functions throughout life. The molecular mechanisms underlying the beneficial adaptations to exercise training are, however, still poorly understood. To improve the mechanistic study of specific exercise training adaptations, standardized, physiological, and well-characterized training interventions are required. Therefore, we performed a comprehensive interrogation of systemic changes and muscle-specific cellular and molecular adaptations to voluntary low-resistance wheel running (Run) and progressive high-resistance wheel running (RR) in young male mice. Following 10 weeks of training, both groups showed similar improvements in body composition and peak oxygen uptake (V̇O2peak ), as well as elevated mitochondrial proteins and capillarization markers in the M. plantaris. Run mice clearly outperformed RR mice in a forced treadmill running capacity test, while RR mice displayed increased grip strength as well as superior mass gains in the M. soleus, associated with distinct proteomic changes specifying the two paradigms. Thus, even though both training modalities induce overlapping adaptations, Run interventions preferably improve submaximal running performance, while progressive RR is a valid model to study training-induced gains in grip strength and plantar flexor hypertrophy.

Effect of high-dose vitamin C and E supplementation on muscle recovery and training adaptation: a mini review.

PURPOSE: This review aimed to investigate the effects of high-dose vitamins C and E supplementation combined with acute or chronic exercise on muscle recovery and training adaptation. METHODS: We used PubMed, Web of Science, and Wiley Online Library databases to perform a literature search based on the keywords 'vitamin C, vitamin E, antioxidants, muscle recovery, training adaptation, and oxidative stress'. RESULTS: Vitamin C or E supplementation has been reported to contribute to a reduction in oxidative stress and muscle damage; however, there is currently inadequate evidence of their positive effects on muscle recovery. Long-term vitamin C or E supplementation can have negative effects on physiological phenomena required for training adaptation, such as strength, muscle hypertrophy, and endurance. Numerous studies emphasized that an adequate diet consisting of fruits and vegetables is a more appropriate way of consuming antioxidants than supplementation. CONCLUSION: The effects of high-dose vitamin C and E supplementation on post-exercise muscle recovery remain unclear and ambiguous, although there is evidence of potential negative effects on training adaptation.

miRNAs as markers for the development of individualized training regimens: A pilot study.

Small, non-coding RNAs (microRNAs) have been shown to regulate gene expression in response to exercise in various tissues and organs, thus possibly coordinating their adaptive response. Thus, it is likely that differential microRNA expression might be one of the factors that are responsible for different training responses of different individuals. Consequently, determining microRNA patterns might be a promising approach toward the development of individualized training strategies. However, little is known on (1) microRNA patterns and their regulation by different exercise regimens and (2) possible correlations between these patterns and individual training adaptation. Here, we present microarray data on skeletal muscle microRNA patterns in six young, female subjects before and after six weeks of either moderate-intensity continuous or high-intensity interval training on a bicycle ergometer. Our data show that n = 36 different microRNA species were regulated more than twofold in this cohort (n = 28 upregulated and n = 8 downregulated). In addition, we correlated baseline microRNA patterns with individual changes in VO2 max and identified some specific microRNAs that might be promising candidates for further testing and evaluation in the future, which might eventually lead to the establishment of microRNA marker panels that will allow individual recommendations for specific exercise regimens.

The Effect of Selected Polymorphisms of the ACTN3, ACE, HIF1A and PPARA Genes on the Immediate Supercompensation Training Effect of Elite Slovak Endurance Runners and Football Players.

We aimed to evaluate the effect of selected polymorphisms of the ACTN3, ACE, HIF1A and PPARA genes on the immediate supercompensation training effect of elite Slovak endurance runners and football players compared with a sedentary control group. Adaptation effect levels were evaluated by 10 s continuous vertical jump test parameters measured by Optojump. Genetic polymorphisms were determined by PCR and Sanger sequencing. We found significant differences in the effect of PPARA genotypes in the experimental group. C allele genotypes represented an advantage in immediate supercompensation (p < 0.05). We observed a significant combined effect of multiple genes on immediate supercompensation (p < 0.05): the RR genotype of the ACTN3 gene, the ID genotype of the ACE gene, the Pro/Pro genotype of HIF1A, and the GC and GG genotypes of PPARA genes. In the control group, we found a significant effect (p < 0.05) on immediate supercompensation of the II genotype of the ACE gene and the Pro/Ser genotype of the HIF1A gene. We found significant differences in genotype frequency of ACE (p < 0.01) and PPARA (p < 0.001) genes. We confirmed that individual genetic polymorphisms of ACTN3, ACE, HIF1A and PPARA genes have a different effect on the level of immediate supercompensation of the lower limbs depending on the training adaptation of the probands and the combination of genotypes.