The impact of EEG biofeedback training on the athletes' motivation and bench press performance.

The objective of this paper was to determine the impact of EEG-biofeedback training on the motivation and efficiency of powerlifters during the bench press exercise in relation to the external load and the level of training. The study included 18 trained powerlifters who were divided into the intermediate (IG) and the advanced (AG) groups. EEG-biofeedback training was conducted every three days, lasting 27 minutes each time (5 × 3-minute intervals with recovery periods - lying on a bench - between them 4 × 3 minutes), and ended with a final EEG measurement in the second cycle of research. The repeated measures ANOVA showed intra-group differences due to external loading for the FAI (Frontal Alpha Asymmetry) obtained in the EEG both before and after biofeedback training. In AG group analysis revealed significant differences between 65%1RM and 35%1RM. In the IG group between 35%1RM and 50, 65 and 80%1RM. One of the major variables influencing the efficiency of strength training, including bench press workouts, is the level of training. The more successfully an athlete uses motivation when exercising, the better their training, which translates into greater results and a lower chance of injury.

Sprint Resisted and Assisted Priming for Peak Performance.

ABSTRACT: Krzysztof, K, Aleksander, M, Adam, Z, and Krzysztofik, M. Sprint resisted and assisted priming for peak performance. J Strength Cond Res 37(12): 2354-2361, 2023-This study aimed to investigate resisted and assisted sprint, or a combination of both, as a conditioning activity (CA) on creatine kinase activity, biceps femoris stiffness, postactivation performance enhancement (PAPE), and priming in a sprint. Ten female sprinters (age: 20.1 ± 2.3 years, body mass: 56.4 ± 4.2 kg, body height: 171 ± 5 cm, training experience: 5.6 ± 2 years) participated. Before the warm-up, blood samples were drawn to determine creatine kinase at baseline. After the warm-up, biceps femoris stiffness was determined, and consequently, 50-m sprint time (with 0- to 20-m and 20- to50-m split time evaluation) was assessed 5 minutes before (pre-CA) and in the seventh minute after the completion of each CA (4 sets of 40 m either: 10% body mass resisted [RST]; 105% maximum velocity assisted [AST] sprint; or 2 sets of each sprint as the CA [COMB]), as well as after 48 hours of recovery. Furthermore, another blood sample was taken 48 hours later, before the warm-up, to assess changes in creatine kinase activity. A significantly higher 20-m sprint time at post-CA ( p = 0.006; ES = 0.4) and post-48 ( p = 0.011; ES = 0.59) compared with pre-CA in the RST condition was found, whereas a significantly lower sprint time was reported in post-48 compared with post-CA ( p = 0.019; ES = 0.44) in the COMB condition. However, a significantly lower 30-m flying sprint time at post-CA ( p < 0.001; ES = 0.28) and at post-48 ( p = 0.014; ES = 0.22) compared with pre-CA in the RST condition was revealed. Moreover, a significantly lower 30-m flying sprint time at post-48 compared with the pre-CA ( p = 0.007; ES = 0.7 and p = 0.003; ES = 0.77) and with the post-CA ( p = 0.019; ES = 0.61 and p = 0.009; ES = 0.68) in the AST condition and COMB was reported. Furthermore, a significantly lower 50-m sprint time at post-48 compared with pre-CA ( p = 0.015; ES = 0.51 and p = 0.011; ES = 0.64) and with post-CA ( p = 0.005; ES = 0.46 and p = 0.001; ES = 0.55) in the AST and COMB condition were found. The creatine kinase activity at post-48 during AST was significantly lower than during RST ( p = 0.028; ES = 0.73) and COMB ( p = 0.028; ES = 1.48). No significant changes were found for biceps femoris stiffness ( p = 0.085; η 2 = 0.199). The COMB and AST contributed to the improvement of the 50-m sprint time 48 hours after activation, which may be a good precompetition approach. However, during training sessions aiming to induce an acute PAPE effect and improve the 30-m flying sprint time, the best solution might be to use low-volume-resisted sprints.

Acute Effects of Varied Back Squat Activation Protocols on Muscle-Tendon Stiffness and Jumping Performance.

ABSTRACT: Krzysztofik, M, Wilk, M, Pisz, A, Kolinger, D, Tsoukos, A, Zajac, A, Stastny, P, and Bogdanis, GC. Acute effects of varied back squat activation protocols on muscle-tendon stiffness and jumping performance. J Strength Cond Res 37(7): 1419-1427, 2023-Intensity, movement velocity, and volume are the principal factors to successfully use postactivation performance enhancement. Therefore, 15 resistance-trained volleyball players completed 3 different back squat configurations as a conditioning activity (CA) in randomized order: (a) 3 sets of 3 repetitions at 85% 1RM (HL); (b) a single set of back squats at 60% 1RM until 10% mean velocity loss (VB); (c) and 2 sets of back squats at 60% 1RM until 10% mean velocity loss (2VB) on subsequent countermovement jump performance, Achilles tendon, and vastus lateralis stiffness with concomitant front thigh skin surface temperature assessment. The measurements were performed 5 minutes before the CA and at 2, 4, 6, 8, and 10 minutes. The jump height was significantly increased in the second minute and at peak, post-CA compared with baseline for all conditions ( p = 0.049; ES = 0.23 and p < 0.001; ES = 0.37). Skin surface temperature was significantly increased for all post-CA time points compared with baseline in the 2VB condition ( p from <0.001-0.023; ES = 0.39-1.04) and in the fourth minute and at peak post-CA in HL condition ( p = 0.023; ES = 0.69 and p = 0.04; ES = 0.46), whereas for the VB condition, a significant decrease in peak post-CA was found ( p = 0.004; ES = -0.54). Achilles tendon stiffness was significantly decreased for second, fourth, eighth, 10th, and peak post-CA in comparison to baseline for all conditions ( p from p = 0.004-0.038; ES = -0.47 to -0.69). Vastus lateralis stiffness was significantly decreased for peak post-CA compared with baseline for all conditions ( p = 0.017; ES = -0.42). We recommend using a single set of barbell squats with a 10% velocity loss as a mechanism of fatigue control to acutely improve jump height performance and avoid unnecessary increases in training volume.

Acute Effects of High-Load vs. Plyometric Conditioning Activity on Jumping Performance and the Muscle-Tendon Mechanical Properties.

ABSTRACT: Krzysztofik, M, Wilk, M, Pisz, A, Kolinger, D, Bichowska, M, Zajac, A, and Stastny, P. Acute effects of high-load versus plyometric conditioning activity on jumping performance and the muscle-tendon mechanical properties. J Strength Cond Res 37(7): 1397-1403, 2023-The effectiveness of high-load and plyometric exercises as conditioning activity (CA) is not well described in the level of performance enhancement and muscle-tendon properties. Therefore, this study aimed to compare the effectiveness of high-loaded back squats and body mass tuck jumps among amateur soccer players on the height of countermovement jump performed without (CMJ) and with arm swing (CMJa) and to verify the usefulness of the myotonometry in assessing the level of CA-induced fatigue. Therefore, 16 male amateur soccer players (resistance training experience: 2 ± 1 year, relative 1 repetition maximum back squat strength: 1.41 ± 0.12 kg·body mass-1) performed 3 experimental sessions to compare the acute effects of 3 sets of 3 repetitions at 85% one repetition maximum of half back squats (HL), 3 sets of 5 repetitions of tuck jump exercises (PLY), and no CA (CTRL) on CMJ and CMJa height. Moreover, the gastrocnemius medialis and Achilles tendon tone and stiffness were examined. Measurements were performed 5 minutes before CA and in the third, sixth, and ninth minutes after CA. The CMJ height significantly increased from pre-CA to post-CA in the CTRL (p = 0.005; effect size [ES] = 0.36; Δ = +3.4%) and PLY (p = 0.001; ES = 0.83; Δ = +8.8%) conditions. Moreover, post-CA jump height was significantly higher in PLY than in the HL condition (p = 0.024; ES = 0.6; Δ = +5.9%). No significant differences were found for CMJa height, tone, and stiffness of gastrocnemius medialis and Achilles tendon. The low-volume plyometric CA (i.e., 3 sets of 5 repetitions) is recommended instead of high-loaded CA (≥85% one repetition maximum) for amateur athletes. In addition, it has been established that the performance improvement was independent of changes in the mechanical properties of the gastrocnemius medialis and Achilles tendon. Furthermore, it seems that the complexity of the post-CA task may affect the magnitude of the postactivation performance enhancement.

Effect of the Bleaching Process on Changes in the Fatty Acid Profile of Raw Hemp Seed Oil (Cannabis sativa).

Many refined oils from soybean, rapeseed, and sunflower, among others, are available on the food market, except olive oil. Refining, on the small production scale of niche oils, is not used due to the high cost of the refining process. Unrefined oils are characterized by intense taste, odor, color, and undesirable nutrients. The problem to be solved is determining the effects of incomplete refining of niche oils on their composition. One process, which does not require the use of complex apparatus, is the bleaching process. The results presented in this article relate to the research stage, in which the aim is to evaluate the changes occurring in the oil due to the low-temperature bleaching process with different process parameters. The presented research results provide evidence of the absence of adverse changes in the fatty acid profile of hemp oil of the varieties 'Finola', 'Earlina 8FC', and 'Secuieni Jubileu'. Seven different types of bleaching earth were used to bleach the oil in amounts of 2.5 and 5 g/100 g of vegetable oil. The fatty acid profile was obtained by gas chromatography (GC-FID). The obtained chromatograms were subjected to statistical analysis and principal component analysis (PCA). The results show that there was no effect of the type of bleaching earth and its amount on the change in the fatty acid profile of bleached oils. Only real differences between the types of hemp oils were observed. However, an overall positive effect of the bleaching process on hemp oil was found. The amount of saturated fatty acid (SFA) was reduced by 17.1% compared with the initial value, resulting in an increase in the proportion of polyunsaturated fatty acids (PUFA) by 4.4%, resulting in an unsaturated fatty acid (UFA) proportion of 90%. There was a significant improvement in the SFA/PUFA ratio by 26% over the baseline, and the omega-6/omega-3 ratio by 8.9% to a value of 3.1:1. The new knowledge from this study is evidence of the positive effect of the low-temperature bleaching process on the fatty acid profile. In contrast, the parameters of the bleaching process itself are not significant.

Chitosan and Its Carboxymethyl-Based Membranes Produced by Crosslinking with Magnesium Phytate.

Membranes produced by crosslinking chitosan with magnesium phytate were prepared using highly deacetylated chitosan and its N-carboxymethyl, O-carboxymethyl and N,O-carboxymethyl derivatives. The conditions of the membrane production were described. IR, Raman, electron absorption and emission spectra were measured and analyzed for all the substrates. It was found that O-carboxymethyl chitosan derivative is the most effectively crosslinked by magnesium phytate, and the films formed on this substrate exhibit good mechanical parameters of strength, resistance and stability. Strong O-H···O hydrogen bonds proved to be responsible for an effective crosslinking process. Newly discovered membrane types produced from chitosan and magnesium phytate were characterized as morphologically homogenous and uniform by scanning electron microscopy (SEM) and IR measurements. Due to their good covering properties, they do not have pores or channels and are proposed as packaging materials.

Postactivation Performance Enhancement of Concentric Bench Press Throw After Eccentric-Only Conditioning Exercise.

ABSTRACT: Krzysztofik, M, Wilk, M, Lockie, RG, Golas, A, Zajac, A, and Bogdanis, GC. Postactivation performance enhancement of concentric bench press throw after eccentric-only conditioning exercise. J Strength Cond Res 36(8): 2077-2081, 2022-This study examined changes in power output and bar velocity in the concentric-only bench press throw (CON ONLY ) after sets of eccentric-only bench press exercises (ECC ONLY ) at 2 supramaximal loads. Thirteen strength-trained men participated in this study (age = 25.7 ± 1.9 years, body mass = 94.8 ± 8 kg, 1 repetition maximum [1RM] = 147 ± 14.2 kg, and strength training experience = 6.5 ± 2.2 years). The subjects performed 2 conditioning sets of the bench press exercise of 2 repetitions each, with a 5-minute rest interval between sets, using the ECC ONLY mode against 110% or 130% of concentric 1RM load. The 1 repetition of the CON ONLY bench press throw with a load of 30% 1RM was performed before and 5 minutes after the conditioning activity (CA) to assess changes in peak power (PP) and peak velocity (PV). The differences between the analyzed variables before and after the CA were determined using a 2-way repeated measures analysis of variance. There was an increase of PP by 10.5 ± 6.0% (effect size [ES] = 0.34) and 9.9 ± 8.1% (ES = 0.33) for the 110 and 130% of concentric 1RM conditions, respectively, with no difference between the 2 conditions ( p < 0.01 main effect time, no interaction). Similarly, PV increased by 5.9 ± 5.5% (ES = 0.40) and 6.1 ± 6.1% (ES = 0.43) for the 110 and 130% of concentric 1RM conditions, respectively, with no difference between the 2 conditions ( p < 0.01 main effect time, no interaction). Activation with an ECC ONLY contraction and loads exceeding 1RM are effective at improving power output and bar velocity during the CON ONLY bench press throw.

Short-Term Blood Flow Restriction Increases Power Output and Bar Velocity During the Bench Press.

ABSTRACT: Wilk, M, Krzysztofik, M, Filip, A, Zajac, A, Bogdanis, GC, and Lockie, RG. Short-term blood flow restriction increases power output and bar velocity during the bench press. J Strength Cond Res 36(8): 2082-2088, 2022-This study examined the effect of blood flow restriction (BFR) with 2 different types of cuffs on peak power output (PP), mean power output (MP), peak bar velocity (PV), and mean bar velocity (MV) in the bench press exercise (BP). Fourteen healthy strength-trained male athletes (age = 27.6 ± 3.5 years; body mass = 84.1 ± 8.0 kg; height = 175.8 ± 6.7 cm; BP 1 repetition maximum [RM] = 138.6 ± 17.8 kg) performed 3 different testing protocols as follows: without BFR (NO-BFR), BFR with a narrow cuff (BFR NARROW ), and BFR with a wide cuff (BFR WIDE ) in a randomized crossover design. During all sessions, subjects performed one set of 3 repetitions of the BP exercise using 70% 1RM. Cuff pressure was set to approximately 90% full arterial occlusion pressure of the upper limb at rest. Analyses of variance showed an increase in PP (by 21%, p < 0.01; effect size [ES] = 1.67), MP (by 16%, p < 0.01; ES = 0.93), PV (by 22%, p < 0.01; ES = 1.79), and MV (by 21%, p < 0.01; ES = 1.36) during BFR WIDE compared with NO-BFR and a significant increase in PP (by 15%, p < 0.01; ES = 1.07), MP (by 17%, p < 0.01; ES = 0.78), PV (by 18%, p < 0.01; ES = 1.65), and MV (by 13% p < 0.01; ES = 1.00) during BFR WIDE compared with BFR NARROW . There were no significant differences in any of the variable between NO-BFR and BFR NARROW . The results of the study indicate that short-term BFR training increases power output and bar velocity during the BP exercise. However, only BFR WIDE significantly influenced bar velocity and power output, which indicates that the width of the cuff is a critical factor determining acute exercise adaptation during BFR resistance training.

Hemp Seeds of the Polish 'Bialobrzeskie' and 'Henola' Varieties (Cannabis sativa L. var. sativa) as Prospective Plant Sources for Food Production.

This publication characterizes the nutritional value of the Polish hemp seeds of the 'Bialobrzeskie' and 'Henola' varieties, including the profile/content of fatty acids and amino acids. Hemp seeds were found to be rich in protein, fat, and dietary fiber. Polyunsaturated fatty acids (PUFA) dominated the unsaturated fatty acids (UFA) profile. Their average share within the total fatty acids (FA) was as high as 75%. Linoleic acid belonging to this group accounted for 55% of the total FA. Lipid profile indices (Σ n - 6/Σ n - 3, Σ PUFA/Σ SFA, the thrombogenicity index, the atherogenicity index and the hypocholesterolemic/hypercholesterolemic ratio) proved the high nutritional value of hemp oil. Considering the tyrosine + phenylalanine and histidine contents, hemp protein exhibited a great degree of similarity to egg protein, which is known and valued for its high biological value.

Acute effects of resisted and assisted locomotor activation on sprint performance.

Sprinting speed is one of the most significant motor abilities in team sport games and all sprint, hurdling and jumping events in athletics. Over the years numerous methods and devices have been developed to improve sprinting performance. One of the most effective methods of developing sprinting speed includes resisted sprinting with the use of different towing devices, parachutes, uphill running, and now intelligent drag technology. Resisted sprinting can be used for chronic changes in performance or for acute enhancement of running speed through locomotor post-activation. The other method of enhancing sprinting speed includes assisted sprinting in which the objective is to achieve supramaximal speed through high speed treadmill running, downhill sprinting, the use of elastic tubing or different towing mechanisms. The main objectives of this research were to determine the acute effects of resisted and assisted sprint activation on sprinting performance in male and female sprinters. Eleven, international and national level 200-400 m sprinters, 6 female and 5 male, participated in the study. The study protocol had a crossover design, with the activation protocol for both days consisting of either 3 × 30 m resisted sprints or 3 × 40 m assisted sprints. At baseline, and following the activation protocol, all athletes performed a 50 m maximum sprint, measured electronically with photocells from a crouched start. During particular trials, the SPRINT 1080 engine assisted measuring system was used with the load set individually to 10% BM. During the resisted and assisted PAP intervention the results of intragroup ANOVA revealed significant differences between resisted baseline results and resisted post activation results in the 10 m and 50 m test trials in men (respectively p = 0.002, η2 = 0.25; p = 0.001, η2 = 0.45), as well as in the group of female sprinters at these distances (10 m and 50 m) (respectively p = 0.002, η2 = 0.20; p = 0.001, η2 = 0.29). There were no statistically significant improvements in the 10 and 50 m test trials following assisted activation for both female and male sprinters. It was concluded that resisted sprint activation with a load of 10% BM enhances sprinting speed over 50 m in elite male and female sprinters.

Changes in EMG and movement velocity during a set to failure against different loads in the bench press exercise.

This study examined changes in movement velocity and surface electromyographic (sEMG) activity of the pectoralis major (PM) and triceps brachii (TB) muscles during the bench press exercise to failure against different loads. Fourteen men performed a set to failure with maximum intended velocity, against low (40%-1 repetition maximum-RM), moderate (60%-1RM), and heavy loads (80%-1RM). Number of repetitions, volume load, mean and peak velocity, and total time increased with decreasing load (40% > 60% > 80%, p < 0.01). sEMG comparisons between different loads were performed by matching time under tension at the initial, middle, and last part of the set. sEMG was higher in the middle and last repetitions, compared with the initial, for all loads in both muscles (p < 0.001). sEMG activity of both muscles was higher in the 60% and 80%-1RM conditions compared with the 40%1-RM (p < 0.007). Also, sEMG of both muscles was similar for the 60%-1RM and 80%-1RM loads at the initial, middle, and last repetitions, with the exception of the last repetitions for the TB muscle. In contrast, sEMG integrated activity was higher for the 40% 1-RM and 60% 1-RM (p < 0.01) compared with the 80% 1-RM load. Mean velocity loss at exhaustion and drop in sEMG median frequency were greater in the 40% and 60%-1RM compared with the 80%-1RM condition (p < 0.05). It was concluded that performing a set to exhaustion with maximum intended velocity using a load of 60% 1-RM combines the characteristics of the high average sEMG activity of heavier loads, and the high total integrated sEMG observed at lighter loads.

Physicochemical Characterization of the Loganic Acid-IR, Raman, UV-Vis and Luminescence Spectra Analyzed in Terms of Quantum Chemical DFT Approach.

The molecular structure and vibrational spectra of loganic acid (LA) were calculated using B3LYP density functional theory, the 6-311G(2d,2p) basis set, and the GAUSSIAN 03W program. The solid-phase FTIR and FT-Raman spectra of LA were recorded in the 100-4000 cm-1 range. The assignment of the observed bands to the respective normal modes was proposed on the basis of the PED approach. The stability of the LA molecule was considered using NBO analysis. The electron absorption and luminescence spectra were measured and discussed in terms of the calculated singlet, triplet, HOMO, and LUMO electron energies. The Stokes shift derived from the optical spectra was 20,915 cm-1.

Bicarbonate supplementation via lactate efflux improves anaerobic and cognitive performance in elite combat sport athletes.

The aim of this study was the assessment of sodium bicarbonate supplementation (NaHCO3 -) on anaerobic and cognitive performance, assuming ergogenic effect of HCO3 by improving buffering capacity and greater lactate efflux, which may have indirect effect on circulating neurotrophin level (e.g BDNF, IGF-1) and memory. Sixteen well-trained judo athletes completed a randomized trial of either a NaHCO3 - (EG) (5000 mg x 2/day/90 min before training)or placebo for 21 days (CG). Before and after treatment, athletes completed double Wingate test (Wt) protocol following which they performed perceived Working Memory test (pWM). Results suggested significant increase in Upper Limb Total Work (with p = 0.011), Mean Power (with p = 0.001), post exercise LA concentration (from 15.51 mmol/L to 18.10 mmol/L with p = 0.01) and HCO3rest concentrations (from 27.37 mmol/l to 28.91 mmol/l with p = 0.001), when compared to baseline values in EG. The analysis showed statistically significant increase in values for IGF-1 (with p = 0.001) and decrease for cortisol and BDNF (with p = 0.001) in EG and CG, when pre and post exercise values were compared. We also revealed statistically significant decrease in values for display time after ingestion of HCO3 between pre and post exercise (with p = 0.002) In conclusion, the lack of a substantial relationship between exerkines (IGF-1, BDNF) and memory in the present study might suggest that exercise induced lactate levels is dominant mechanism improving working memory in well-train athletes.

The Influence of Movement Tempo on Acute Neuromuscular, Hormonal, and Mechanical Responses to Resistance Exercise-A Mini Review.

Wilk, M, Tufano, JJ, and Zajac, A. The influence of movement tempo on acute neuromuscular, hormonal, and mechanical responses to resistance exercise-a mini review. J Strength Cond Res 34(8): 2369-2383, 2020-Resistance training studies mainly analyze variables such as the type and order of exercise, intensity, number of sets, number of repetitions, and duration and frequency of rest periods. However, one variable that is often overlooked in resistance training research, as well as in practice, is premeditated movement tempo, which can influence a myriad of mechanical and physiological factors associated with training and adaptation. Specifically, this article provides an overview of the available scientific literature and describes how slower tempos negatively affect the 1-repetition maximum, the possible load to be used, and the number of repetitions performed with a given load, while also increasing the total time under tension, which can mediate acute cardiovascular and hormonal responses. As a result, coaches should consider testing maximal strength and the maximal number of repetitions that can be performed with each movement tempo that is to be used during training. Otherwise, programming resistance training using various movement tempos is more of a trial-and-error approach, rather than being evidence or practice based. Furthermore, practical applications are provided to show how movement tempo can be adjusted for a variety of case study-type scenarios.

The effects of resistance training experience on movement characteristics in the bench press exercise.

The main aim of this study was to determine whether the level of experience in strength training has a significant effect on differences in the value of exercise volume determined on time under tension (TUT) and number of repetition (REP) for a specific movement tempo. The study examined 68 men divided into groups of beginners and advanced strength trained athletes. The participants performed 5 sets of bench press (BP) at 70% 1RM using either a REG, MED or SLOW metronome guided cadence. Each set was performed to failure and with 3 min of rest between sets. Significant differences in TUT were found between the groups of beginners and advanced athletes for the slow (SLO) 6/0/4/0 tempo in set 1 (p = 0.01) and set 2 (p = 0.04), and for the regular (REG) 2/0/2/0 tempo in set 5 (p = 0.01). Significant differences were documented for total TUT between the beginners and advanced athletes for the SLO 6/0/4/0 tempo (p = 0.04). The results of ANOVA revealed significant differences in the number of repetitions between groups for the SLO 6/0/4/0 tempo in set 4 (p = 0.04) and set 5 (p = 0.04), and for the REG 2/0/2/0 tempo in set 5 (p = 0.01). The main finding of this study is that strength training experience has a significant effect on training volume, both in terms of TUT and REP at a specific constant movement tempo. Significant differences do not occur for each value of the tempo used.

Impact of Duration of Eccentric Movement in the One-Repetition Maximum Test Result in the Bench Press among Women.

Scientific studies related to resistance training have considered many variables; however, the tempo of movement of particular repetitions is often neglected or not reported in resistance training practice and research. The aim of the study was to determine the effect of different duration of the eccentric (ECC) phase of movement on one-repetition maximum test (1RM) results during the bench press exercise (BP). Twenty-one strength trained females (age = 23.4 ± 2.2 years, body mass = 52.3 ± 6.7 kg), with a minimum one year of strength training experience took part in the study. The experiment was conducted following a randomized crossover design, where each participant completed the 1RM test in the BP with three different duration times of the ECC movement: 2/0/X, 4/0/X, 6/0/X. Concentric (CON) movement was performed with maximal velocity (X). The ANOVA with repeated measures were used to compare the differences between the analyzed variables. The results of the study indicated the maximal load in the 1RM test was significantly higher during the BP with the 2/0/X tempo compared to 6/0/X (p < 0.01) and 4/0/X tempos (p < 0.01). Therefore, the results indicated that the longer the duration of the ECC phase of movement, the greater the decrease in the result of the 1RM test. The 1RM test procedure should include information about the movement tempo used during the test protocol.

Association of Elite Sports Status with Gene Variants of Peroxisome Proliferator Activated Receptors and Their Transcriptional Coactivator.

BACKGROUND: Although the scientific literature regarding sports genomics has grown during the last decade, some genes, such as peroxisome proliferator activated receptors (PPARs), have not been fully described in terms of their role in achieving extraordinary sports performance. Therefore, the purpose of this systematic review was to determine which elite sports performance constraints are positively influenced by PPARs and their coactivators. METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were used, with a combination of PPAR and sports keywords. RESULTS: In total, 27 studies that referred to PPARs in elite athletes were included, where the Ala allele in PPARG rs1801282 was associated with strength and power elite athlete status in comparison to subelite athlete status. The C allele in PPARA rs4253778 was associated with soccer, and the G allele PPARA rs4253778 was associated with endurance elite athlete status. Other elite status endurance alleles were the Gly allele in PPARGC1A rs8192678 and the C allele PPARD rs2016520. CONCLUSIONS: PPARs can be used for estimating the potential to achieve elite status in human physical performance in strength and power, team, and aerobic sports disciplines. Carrying specific PPAR alleles can provide a partial benefit to achieving elite sports status, but does not preclude achieving elite status if they are absent.

The Effects of Eccentric Cadence on Power and Velocity of the Bar during the Concentric Phase of the Bench Press Movement.

Training at a specific movement tempo is a relatively new concept in resistance training. It is based on manipulation of the duration of particular phases of a movement. General studies have demonstrated that faster movement tempo in resistance training leads to an increase in muscle power, whereas lower movement speed is beneficial in the development of muscle strength and hypertrophy. However, the studies in this area are inconclusive and do not relate precisely to various tempos and movement speeds. The aim of the study was to determine the effect of duration of the eccentric cadence ECCREG (2/0/X/0) and ECCSLO (6/0/X/0) on muscular power generated in the concentric phase of the movement expressed in maximal PMAX, VMAX and average values PAVE, VAVE. For the ECCSLO (6/0/X/0) cadence, a significantly lower value of P (401.95 ± 65.42 W) was observed compared to the ECCREG 2/0/X/0 tempo (467.65 ± 79.18 W), at p = 0.007. The same was true for power evaluated in maximal values (PMAX), as significantly higher values were recorded for the regular ECCREG (2/0/X/0) (671.55 ± 115.79 W) compared to the slow tempo ECCSLO (6/0/X/0) (565,70 ± 117,37 W), at the level of significance of p = 0.007. The velocity evaluated for ECCREG (2/0/X/0) tempo expressed in average values (VAVE) 0.60±0.09 m/s was significantly higher compared to the ECCSLO (6/0/X/0) tempo (0.52 ± 0.08 m/s), with p=0.004. When maximal velocity (VMAX), was considered higher values for ECCREG (2/0/X/0) tempo was registered (0.79 ± 0.10 m/s) compared to the ECCSLO (6/0/X/0) tempo (0.69 ± 0.13 m/s), at significance of p = 0.001. The main finding of the study indicates that the duration of the eccentric phase of the movement has a significant impact on muscular power and velocity during the concentric phase of the movement.

Endocrine response to high intensity barbell squats performed with constant movement tempo and variable training volume.

OBJECTIVE: Research indicates that among the many elements of resistance exercise protocols, training volume and total training load are the key factors for post-exercise increase in the secretion of testosterone (T), growth hormone (GH), insulin-like growth factor (IGF-1) and cortisol (C). The aim of this study was to determine the effects of resistance exercises with variable volume and constant intensity and movement tempo on post-exercise concentrations of selected anabolic and catabolic hormones. MATERIALS AND METHODS: 28 experienced powerlifters (27.8 ± 2.9 years, with 6.64 ± 1.29 years of training experience, average body mass of 85.3 ± 3.3 kg and body height of 165.8 ± 10.3 cm) who compete at the national and international level performed three repetitions of barbell squats with a constant external load of 90% 1RM and variable volume (3, 6 and 12 sets of squats) in three stages (pre-exercise, immediately post exercise, and 1h after exercise) over three consecutive weeks. Venous blood samples (10ml) were collected from the antecubital vein, to determine pre- and post-exercise values of the following variables T, GH, IGF-1, C, at rest, immediately after the cessation of the last set of squats, and after 60 minutes of recovery. RESULTS: The T test showed that performing 6 and 12 sets resulted in increases of post exercise GH (p<0.01). Performing 6 sets of squats resulted in post exercise decrease (p<0.01) in IGF-1 and C. Performing 3 sets of squats resulted in immediate post exercise decrease of IGF-1 (p<0.01), which was not maintained 1h after exercise. There were no other significant differences in analysed variables, with the training volume of three sets of three repetitions, confirming previous data suggesting that low volume is the limiting factor in increased post-exercise secretion. CONCLUSION: This study demonstrated that in terms of endocrine response, the optimal volume of high intensity strength exercise is six sets. Therefore, intentionally high volume (12 sets) or low volume (3 sets) are not an effective stimuli for endocrine responses of trained individuals. The 6 sets of squats seems to drive hormonal responses of GH, C and IGF-1, which may play a significant role in stimulating muscle growth and tissue regeneration.

Physiological responses to different neuromuscular movement task during eccentric bench press.

OBJECTIVES: Increasing muscular hypertrophy is one of the main reasons for participating in a resistance training program, where different movement task such as eccentric cadences may serve as a potent hypertrophic stimulus and improve movement stability. Aim of this study was to investigate the physiological responses between slow 6/0/2/0 (SLOW) and moderate 2/0/2/0 (REG) eccentric cadences during five sets of bench press to failure using 70% 1 repetition maximum (1RM). MATERIALS AND METHODS: Blood samples from sixteen men (21-29y, 85.9±7.7kg, 130±17.5kg bench press 1RM) with at least five years of resistance training experience were taken before, immediately after, 30 min after, and 60 min after both protocols in a randomized cross over study design. RESULTS: ANOVA showed that more repetitions were performed during each set in REG and for the entire REG protocol (p<0.001), but total time under tension was greater during SLOW in each set and for the entire protocol (p<0.001). The post-exercise levels of lactate (p=0.02), creatine kinase (p=0.04), and testosterone (p=0.01) were greater after SLOW. Post-exercise cortisol levels decreased in both protocols (p<0.001), but these decreases were not significantly different between protocols. CONCLUSIONS: Therefore, intentionally slow eccentric speeds and increased eccentric time under tension seem to be effective for increasing acute hormonal responses after exercise. As such, although a SLOW tempo may decrease the amount of total work (i.e. fewer repetitions with the same load), the increased time under tension seems to drive hormonal responses and neurological response, which may play a large role in stimulating muscle growth, coordination and movement stability.