Miroslav Petr

PPARA intron polymorphism associated with power performance in 30-s anaerobic Wingate Test.

To date, polymorphisms in several genes have been associated with a strength/power performance including alpha 3 actinin, ciliary neurotrophic factor, vitamin D receptor, or angiotensin I converting enzyme, underlining the importance of genetic component of the multifactorial strength/power-related phenotypes. The single nucleotide variation in peroxisome proliferator-activated receptor alpha gene (PPARA) intron 7 G/C (rs4253778; g.46630634G>C) has been repeatedly found to play a significant role in response to different types of physical activity. We investigated the effect of PPARA intron 7 G/C polymorphism specifically on anaerobic power output in a group of 77 elite male Czech ice hockey players (18–36 y). We determined the relative peak power per body weight (Pmax.kg−1) and relative peak power per fat free mass (W.kg−1 FFM) during the 30-second Wingate Test (WT30) on bicycle ergometer (Monark 894E Peak bike, MONARK, Sweden). All WT30s were performed during the hockey season. Overall genotype frequencies were 50.6% GG homozygotes, 40.3% CG heterozygotes, and 9.1% CC homozygotes. We found statistically significant differences in Pmax.kg−1 and marginally significant differences in Pmax.kg−1 FFM values in WT30 between carriers and non-carriers for C allele (14.6±0.2 vs. 13.9±0.3 W.kg−1 and 15.8±0.2 vs. 15.2±0.3 W.kg−1 FFM, P = 0.036 and 0.12, respectively). Furthermore, Pmax.kg−1 FFM strongly positively correlated with the body weight only in individuals with GG genotypes (R = 0.55; p<0.001). Our results indicate that PPARA 7C carriers exhibited higher speed strength measures in WT30. We hypothesize that C allele carriers within the cohort of trained individuals may possess a metabolic advantage towards anaerobic metabolism.

Strengthening the Gluteus Medius Using Various Bodyweight and Resistance Exercises

ABSTRACT THE GLUTEUS MEDIUS (GMED) IS AN IMPORTANT MUSCLE AND, IF WEAK, CAN CAUSE KNEE, HIP, OR LOWER-BACK PATHOLOGIES. THIS ARTICLE REVIEWS METHODS OF GMED STRENGTH ASSESSMENT, PROVIDES EXERCISES THAT TARGET THE GMED BASED ON ELECTROMYOGRAPHY, PRESENTS HOW TO IMPLEMENT GMED STRENGTHENING IN HEAVY RESISTANCE TRAINING PROGRAMS, AND EXPLAINS THE IMPORTANCE OF INCLUDING THESE EXERCISES IN THESE PROGRAMS.

A systematic review of surface electromyography analyses of the bench press movement task

Background The bench press exercise (BP) plays an important role in recreational and professional training, in which muscle activity is an important multifactorial phenomenon. The objective of this paper is to systematically review electromyography (EMG) studies performed on the barbell BP exercise to answer the following research questions: Which muscles show the greatest activity during the flat BP? Which changes in muscle activity are related to specific conditions under which the BP movement is performed? Strategy PubMed, Scopus, Web of Science and Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library were searched through June 10, 2016. A combination of the following search terms was used: bench press, chest press, board press, test, measure, assessment, dynamometer, kinematics and biomechanics. Only original, full-text articles were considered. Results The search process resulted in 14 relevant studies that were included in the discussion. The triceps brachii (TB) and pectoralis major (PM) muscles were found to have similar activity during the BP, which was significantly higher than the activity of the anterior deltoid. During the BP movement, muscle activity changes with exercise intensity, velocity of movement, fatigue, mental focus, movement phase and stability conditions, such as bar vibration or unstable surfaces. Under these circumstances, TB is the most common object of activity change. Conclusions PM and TB EMG activity is more dominant and shows greater EMG amplitude than anterior deltoid during the BP. There are six factors that can influence muscle activity during the BP; however, the most important factor is exercise intensity, which interacts with all other factors. The research on muscle activity in the BP has several unresolved areas, such as clearly and strongly defined guidelines to perform EMG measurements (e.g., how to elaborate with surface EMG limits) or guidelines for the use of exact muscle models.

Assessment of diagnostics tools for sarcopenia severity using the item response theory (IRT)

ObjectiveTo use the item response theory (IRT) methods to examine the degree to which the four selected tools reflect sarcopenia and to arrange them according to their ability to estimate sarcopenia severity.DesignA cross-sectional study aimed at verifying the possibilities of using diagnostic tools for sarcopenia.Setting and ParticipantsThe study included residents living in an assisted living unit at the Senior Centre in Blansko (South Moravia, Czech Republic) (n=77). Sarcopenia was estimated according to the proposals of the European Working Group on Sarcopenia in Older People (EWGSOP) using calf circumference, the EWGSOP algorithm, hand grip strength, and the Short Physical Performance Battery (SPPB).ResultsThe results from the IRT model showed that these four methods indicate strong unidimensionality so that they measure the same latent variable. The methods ranked according to the discrimination level ranging from high to low discrimination where the calf circumference was the most discriminatory (Hi = 0.86) and the SPPB together with hand grip strength were the least discriminatory (both Hi = 0.44).ConclusionWe are recommending to identify mild sarcopenia by SPPB or hand grip strength, moderate sarcopenia by the EWGSOP algorithm and severe sarcopenia by the calf circumference.

The Role of Supplemented Creatine in Human Metabolism

This review is focused on creatine (CR) (methyl guanidine acetic acid) and its application in the form of a dietary supplement. It has been especially utilized by athletes, but its pronounced therapeutic potential is also discussed in the present article. It is supposed that human body uses CR for the formation of creatine phosphate (PCr), which is necessary for muscular work as a source of energy. The effects of supplemented CR on dynamics of methionine cycle and other related metabolic pathways have not been fully explained yet. The review is focused on the description of affects caused by its application on human body and metabolism. Already the application of small amounts of CR rapidly increases levels of thiodiglycolic acid (TDGA) in urine after its supplementation, which phenomenon can serve as a sensitive marker of disturbance in metabolic pathways of 2C units and of thiolic compounds. Strong differences between initial and terminal TDGA levels in urine indicate that CR disturbed the equilibria of redox processes, catalyzed by folates and vitamin B12. Some theories for explanation of these effects are described in this manuscript. Nevertheless, similarly as in other metabolic studies, the results are significantly affected by the probands’ individual responses, which reflect their individual genetic make-

Association between clinical measures of sarcopenia in a sample of community-dwelling women

BACKGROUND: Sarcopenia is defined as a loss of muscle mass and strength as well as a reduction in physical performance with aging. This study was undertaken to examine the association between specific measures of muscle mass, muscle strength, and physical performance in older women. METHODS: Sixty-nine community-dwelling women with an average age of 66 years (range 60–79) participated in this study. Their muscle mass was described using bioelectric impedance analysis (BIA), their muscle strength was characterized using hand-grip dynamometry (HGD) and their physical performance was denoted using gait speed. Associations between the measures were examined using Pearson correlations and factor analysis. RESULTS: The correlation between muscle mass and muscle strength was strong and significant (p < 0.001), whereas the correlation between both variables and gait speed was poor and not significant. The factor analysis showed that gait speed (loading = −0.235) was not part of the same component as muscle mass and grip strength. CONCLUSIONS: Muscle mass and muscle strength were very closely linked with one another but not with gait speed. Muscle mass and strength represent a different component of sarcopenia than physical performance, at least as represented by gait speed.

The Role of Visual Feedback on Power Output During Intermittent Wingate Testing in Ice Hockey Players

Background: Visual feedback may help elicit peak performance during different types of strength and power testing, but its effect during the anaerobic Wingate test is unexplored. Therefore, the purpose of this study was to determine the effect of visual feedback on power output during a hockey-specific intermittent Wingate test (AnWT6x6) consisting of 6 stages of 6 s intervals with a 1:1 work-to-rest ratio. Methods: Thirty elite college-aged hockey players performed the AnWT6x6 with either constant (n = 15) visual feedback during all 6 stages (CVF) or restricted (n = 15) visual feedback (RVF) where feedback was shown only during the 2nd through 5th stages. Results: In the first stage, there were moderate-to-large effect sizes for absolute peak power (PP) output and PP relative to body mass and PP relative to fat-free mass. However, the remaining stages (2–6) displayed small or negligible effects. Conclusions: These data indicate that visual feedback may play a role in optimizing power output in a non-fatigued state (1st stage), but likely does not play a role in the presence of extreme neuromuscular fatigue (6th stage) during Wingate testing. To achieve the highest peak power, coaches and researchers could provide visual feedback during Wingate testing, as it may positively influence performance in the early stages of testing, but does not result in residual fatigue or negatively affect performance during subsequent stages.

The Role of Peroxisome Proliferator-Activated Receptors and Their Transcriptional Coactivators Gene Variations in Human Trainability: A Systematic Review

Background: The peroxisome proliferator-activated receptors (PPARA, PPARG, PPARD) and their transcriptional coactivators’ (PPARGC1A, PPARGC1B) gene polymorphisms have been associated with muscle morphology, oxygen uptake, power output and endurance performance. The purpose of this review is to determine whether the PPARs and/or their coactivators’ polymorphisms can predict the training response to specific training stimuli. Methods: In accordance with the Preferred Reporting Items for Systematic Reviews and Meta Analyses, a literature review has been run for a combination of PPARs and physical activity key words. Results: All ten of the included studies were performed using aerobic training in general, sedentary or elderly populations from 21 to 75 years of age. The non-responders for aerobic training (VO2peak increase, slow muscle fiber increase and low-density lipoprotein decrease) are the carriers of PPARGC1A rs8192678 Ser/Ser. The negative responders for aerobic training (decrease in VO2peak) are carriers of the PPARD rs2267668 G allele. The negative responders for aerobic training (decreased glucose tolerance and insulin response) are subjects with the PPARG rs1801282 Pro/Pro genotype. The best responders to aerobic training are PPARGC1A rs8192678 Gly/Gly, PPARD rs1053049 TT, PPARD rs2267668 AA and PPARG rs1801282 Ala carriers. Conclusions: The human response for aerobic training is significantly influenced by PPARs’ gene polymorphism and their coactivators, where aerobic training can negatively influence glucose metabolism and VO2peak in some genetically-predisposed individuals.

P-8 Is the AMPD1 polymorphism associated with aerobic performance?

We studied frequencies of AMPD1 C34T, UCP2 Ala55Val, ACE I/D, BDKRB2 + 9/−9 and NOS3 Glu298Asp variants in a group of triathletes who were participants of Czechman Triathlon Race 2013 in the Czech Republic. Buccal swap samples were taken from 118 competitors but from only 101 of them we gained complete data including the final race time. Our results showed that only frequency AMPD1 CT genotype was significantly overrepresented in a group of athletes who finished the race in 300 min compared to athletes did not (36.1% vs. 12.3%; P = 0.007) while AMPD1 TT genotype was missing in our group of subjects. This test also fails to reject the null hypothesis that the population is in Hardy-Weinberg equilibrium (χ 2 = 1,3499; df = 1; p = 0.25). Adenosine monophosphate deaminase (AMPD) is one of the most important regulators of muscle energy metabolism during exercise. AMPD displaces the equilibrium of the myokinase reaction toward ATP production (2 ADP ↔ ATP +AMP) by converting AMP to inosine monophosphate (IMP). An activity of this enzyme, encoded by AMPD1 gene, can be affected by the C34T genetic polymorphism. These results are quite surprising in the light of previously published studies where 34T allele is considered to be relatively unfavourable for sports performance in general. On the other hand, our results are consistent with the recently published study Lifanov et al. (2014) showing higher frequencies of 34T allele in soccer players compared to sedentary controls. Thus 34T allele could potentially be useful for long-term endurance activities. Acknowledgment This research has been supported by the project of Ministry of Education Youth and Sport, Czech Republic [PRVOUK n. 38]. References Lifanov D, Khadyeva MN, Rahmatullina L, Demenev S V, Ibragimov, RR. Effect of creatine supplementation on physical performance are related to the AMPD1 and PPARG genes polymorphisms in football players. Rossiiskii Fiziologicheskii Zhurnal Imeni I. M. Sechenova, 2014 Jun;100(6):767–776. Sole X, Guino E, Valls J, Iniesta R, Moreno, V. SNPStats: a web tool for the analysis of association studies. Bioinformatics, 2006 Aug;22(15):1928–1929.

Effects of Krankcycle Training on Performance and Body Composition in Wheelchair Users

Abstract Innovation in training equipment is important for increasing training effectiveness, performance and changes in body composition, especially in wheelchair users with paraplegia. The main objective of a workout session is to induce an adaptation stimulus, which requires overload of involved muscles by voluntary effort, yet this overload may be highly influenced by the size of the spinal cord lesion. Krancykl construction is designed to allow exercise on any wheelchair and with adjustable height or width of crank handles, where even the grip handle may be altered. The aim of this study was to determine the differences in body composition, performance and the rate of perceived exertion (RPE) in paraplegics with a different level of paralyses after a 12 week training programme of a unilateral regime on Krankcycle equipment (a crank machine). The study sample included four men and one women at a different spine lesion level. The 12 weeks programme was successfully completed by four participants, while one subject got injured during the intervention process. Three participants were paraplegics and one was quadriplegic with innervation of the biceps humeri, triceps humeri and deltoideus. The Krankcycle 30 min programme was followed by four other exercises, which were performed after themselves rather than in a circuit training manner as the latter would result in much longer rest periods between exercises, because paraplegics have to be fixed by straps during exercise on hydraulic machines. The RPE after the workout decreased following the twelve week adaptation period.