Repetition Maximum Test Research Articles

Asymmetry in strength training: Investigating the Impact of offset training on the deep stabilisation system, strength/performance, and maximal power in Female Softball Players

PurposeThis study aims to fill a significant gap in sports science research by examining the underexplored effects of asymmetric load training on the deep stabilisation system (DSS), strength, and maximal power in female softball players.MethodsFourteen participants were divided into two groups: a control group (CON), which exercised with a symmetrically weighted bar, and an experimental group (EXP), which used a bar with asymmetrically distributed weight. The asymmetric load with a distribution of weight that was gradually increased during the 8-week intervention program. The assessment included a 1 repetition maximum (1RM) test for deadlift, flat bench press, front squat, and 4RM tests for single-leg leg press for both legs, along with evaluations of DSS and strength/performance, before and after a resistance training program. A two-way ANOVA was used to compare pre- and post-intervention performance on the DSS and 1RM strength tests.ResultsThe results showed significant improvements in all 1RM and 4RM tests for both groups in all exercises (<i>p</i> > 0.001), with no significant differences between the groups (<i>p</i> < 0.05). However, a dependent <i>t</i>-test in the EXP group revealed significant improvements in DSS strength/performance from pre- to post-measurements in all tests, with large effect sizes. In contrast, the CON group showed significant improvements only in trunk extension, side plank, and prone tests.ConclusionsThese findings indicate that asymmetric training may provide superior benefits in strengthening the DSS, while still achieving comparable gains in maximal strength.

Prediction of Snatch and Clean and Jerk Performance From Physical Performance Measures in Elite Male Weightlifters.

Sandau, I and Kipp, K. Prediction of snatch and clean and jerk performance from physical performance measures in elite male weightlifters. J Strength Cond Res XX(X): 000-000, 2024-This study aimed to build a valid model to predict maximal weightlifting competition performance using ordinary least squares linear regression (OLR) and penalized (Ridge) linear regression (penLR) in 29 elite male weightlifters. One repetition maximum (1RM) or 3RM test results of assistant exercises were used as predictors. Maximal performance data of competition and assistant exercises were collected during a macrocycle in preparation for a competition. One repetition maximum snatch pull, 3RM back squat, 1RM overhead press, and body mass were used to predict the 1RM snatch; and 1RM clean pull, 3RM front squat, 1RM overhead press, and body mass were used to predict the 1RM clean and jerk. Model validation was performed using cross-validation (CV) and external validation (EV; random unknown dataset) for the coefficient of determination and root mean square error (RMSE). Results revealed that penLR models present more plausible output in the relative importance of highly correlated predictors. Of note, the 1RM snatch pull is the most relevant predictor for the 1RM snatch, whereas the 1RM clean pull and 3RM front squat are the most relevant predictors for the 1RM clean and jerk. Validation-based absolute predictive error (RMSE) ranged between ≈ 3-9 kg for the 1RM snatch and ≈ 3-7 kg for the 1RM clean and jerk, depending on the model (OLR vs. penLR) and validation procedure (CV vs. EV). In conclusion, penLR models should be used over OLR models to analyze highly correlated predictors because of more plausible model coefficients and smaller predictive errors.

Effect of a honey-sweetened beverage on muscle soreness and recovery of performance after exercise-induced muscle damage in strength-trained females.

This study explores a novel approach to mitigating delayed-onset muscle soreness (DOMS), a common issue among strength-trained females. By investigating the potential of a honey-sweetened beverage, which contains anti-inflammatory properties, we aim to enhance muscle recovery after exercise-induced muscle damage (EIMD). A randomized, cross-over, placebo-controlled, and double-blinded study was conducted with sixteen female strength athletes. Firstly, the baseline measurements were recorded, and participants were randomly divided into two conditions: honey-sweetened beverage (HSB; 70g of honey in 250mL water with a concentration of 28%) and placebo (PLA; 250mL of water with 70g of artificial sweetener). The HSB and PLA were consumed 90min before the EIMD started (200 vertical jumps with 10% body-weighted vests). Recovery monitoring of performance indicators and DOMS was performed after EIMD. The results of wall-sit, V-Sit and reach flexibility test (VSFT), vertical jump height (VJH), pressure pain threshold (PPT), and one repetition maximum (IRM) tests were recorded 48h after EIMD. Also, DOMS was recorded using the visual analog scale (VAS) before the start of the test and immediately, 12, 24, and 48h after EIMD. A one-week interval was considered a washout period for each condition. The collected data were analyzed by repeated measures of ANOVA and Bonferroni post hoc test and dependent t-test at P ≤ 0.05 level. Compared to PLA, HSB ingestion improves wall-sit performance (p = 0.003), 1RM (p = 0.019), and RPE (p = 0.003) after EIMD. However, no significant differences were observed between BL, PLA, and HSB in VJH (p = 0.384), VSFT (p = 0.840), and PPT (p = 0.151) after EIMD. Furthermore, HSB, compared to PLA, considerably decreased the values of DOMS immediately, 12, 24, and 48h after EIMD (p < 0.05). Our findings illustrated that ingesting HSB in strength-trained females can be a helpful strategy for improving recovery indicators such as muscle strength, endurance, and muscle soreness after EIMD.

Kinetics and Kinematics of the Push Press, Push Jerk, and Split Jerk.

Abstract Soriano, MA, Jiménez-Ormeño, E, Lake, JP, McMahon, JJ, Gallo-Salazar, C, Mundy, P, and Comfort, P. Kinetics and kinematics of the push press, push jerk, and split jerk. J Strength Cond Res 38(8): 1359–1365, 2024—The aim of this study was to explore the kinetics and kinematics across incremental loads with the push press (PP), push jerk (PJ), and split jerk (SJ). Eighteen resistance-trained men performed the 1 repetition maximum (1RM) tests (visit 1) 3–7 days before an incremental loading protocol (60, 75, and 90% 1RM) of the 3 exercises (visit 2). Kinetics and kinematics were derived from force-time data and compared using a repeated-measures analysis of variance with load and exercise as within-subject factors. Dependent variables for the biomechanics assessment were categorized as output (power and impulse), driver (force and work), and strategy (displacement and duration) metrics. The interrepetition reliability was assessed using the intraclass correlation coefficient and coefficient of variation. The PP, PJ, and SJ 1RM performance were 89.7 ± 15.4, 95.6 ± 14.4, and 103.0 ± 16.9 kg, respectively. Driver, strategy, and outcome metrics displayed moderate-to-excellent (intraclass correlation coefficient: 0.58–0.98) reliability with acceptable variability (% coefficient of variation: 2.02–10.00). Increased load resulted in significantly large increases in force, work, displacement, duration, power, and impulse (p &lt; 0.001, = 0.534–0.903). Exercise selection had a significant and large effect on power, impulse, work, and force (p &lt; 0.016, = 0.387–0.534). There was a significant and large effect of load × exercise interaction on work, displacement, and duration (p &lt; 0.019, = 0.158–0.220). Practitioners are encouraged to use heavier loads (90 &gt; 75 &gt; 60% 1RM) during the SJ exercise to maximize output, driver, and strategy kinetics and kinematics.

4-6 Repetition Maximum (RM) and 1-RM Prediction in Free-Weight Bench Press and Smith Machine Squat Based on Body Mass in Male Athletes.

Dhahbi, W, Padulo, J, Russo, L, Racil, G, Ltifi, M-A, Picerno, P, Iuliano, E, and Migliaccio, GM. Four- to 6-repetition maximum and 1-repetition maximum estimation in free-weight bench press and smith machine squat based on body mass in male athletes. J Strength Cond Res 38(8): 1366-1371, 2024-This study aimed to explore the feasibility and face validity of predicting maximum strength 1 repetition maximum (1-RM) and 4-6 RM in athletes across different sports specialties, based on the relationship between muscle strength and BM. One hundred fifteen male athletes, aged 23.63 ± 6.77 years and participating in diverse sports specialties, were included in this study. Muscle strength was assessed using the 4-6 RM and 1-RM tests in free-weight bench press (BP) and Smith machine squat (SQ) exercises, whereas BM was measured using a portable digital scale. A linear regression equation based on muscle strength and BM was performed. The 4-6 RM and 1-RM scores showed excellent intersession relative reliability (intraclass correlation coefficient (2,1) : 0.946-0.989) and absolute reliability (CV: 3.4-4.7%) in both BP and SQ exercises. In addition, the magnitude of the relationship and the coefficients used to estimate the 4-6 RM and 1RM, based on BM, differed among the subjects when they are grouped according to their sports specialties ( R2 ranged from non-significant to 0.998). Overall, the 4-6 RM test showed a stronger correlation with BM ( R : 0.655 for SQ and R : 0.683 for BP) than the 1RM ( R : 0.552 for SQ and R : 0.629 for BP), and the general (i.e., not sport-specific) 4 to 6-RM prediction equations should be preferred over sport-specific ones because they are statistically more robust due to the larger sample size. In conclusion, the 4-6 RM can be predicted from BM with high reliability, a moderate association, and a prediction error that, when considering the 4-6 RM as a starting point for estimating of the 1RM, can be considered entirely acceptable in practical settings.

Combined physical exercise re-synchronizes expression of Bmal1 and REV-ERBα and up-regulates apoptosis and metabolism in the prostate during aging

BackgroundAging increases the prevalence of prostate cancer. The circadian clock coordinates metabolism, cell cycle, and tumor suppressor p53. Although physical exercise has several effects on preventing prostate diseases, its effect on regulating genes and proteins of the circadian rhythm of the prostate needs to be better evaluated. The present study verified expression of REV-ERBα (Nr1d1), Bmal1, apoptosis, tumor suppressors, energetic metabolism markers, and androgen receptors in the prostatic microenvironment in 18-month-old mice submitted to combined physical training. MethodsC57BL/6 J mice were divided into 2 groups: 6 months-old (n = 10) and 18 months-old, (n = 20). The 18-month-old animals were divided into 2 subgroups: sedentary (n = 10, 18 m Sed) and submitted to combined physical training (n = 10, 18 m TR). Combined physical training protocol was performed by running on the treadmill (40–60 % of incremental load test) and climbing strength training (40–50 % of maximum repetition test), consisting of 5×/week (3 days aerobic and 2 days strength) for 3 weeks. The prostate was prepared for Western blot and RT-qPCR analysis, and the plasm was prepared for the biochemistry analysis. ResultsCombined physical exercise during aging led to increased levels of Bmal1 and decreased levels of REV-ERBα in the prostate. These results were accompanied by a reduction in the AMPK/SIRT1/PGC-1α proteins and an increase in the PI3K/AKT and p53/PTEN/caspase 3 pathways, promoting apoptotic potential. ConclusionThese findings suggest that strength and aerobic physical exercise may be preventive in the development of preneoplastic molecular alterations and age-related features by re-synchronizes Bmal1 and REV-ERBα in prostatic tissues.

Dose-Response Effects of Short-Term Rhodiola rosea Supplementation on Anaerobic Exercise Performance in Resistance-Trained Athletes: A Randomized, Crossover, Double-Blind, and Placebo-Controlled Study

Background: Rhodiola rosea (RR) has garnered attention for its potential ergogenic effects on athletic performance. The mechanisms underlying these effects are believed to involve improved energy metabolism and reduced exercise-induced oxidative stress. Methods: Twenty-seven resistance-trained individuals (13 males, 14 females; 22±3y; 170.4±10.7cm; 75.4±21.9kg) underwent three conditions in a randomized sequence: a low-dose RR (LD: 200mg/d of RR combined with 1.3g/d of maltodextrin), a high-dose RR (HD: 1.5g/d of RR), and a placebo (PL: 1.5g/d of maltodextrin), following an initial baseline (BL) assessment. Participants took supplements for seven days and a 7-day washout before transitioning to the subsequent conditions. Data were analyzed using a two-way (within-within) analysis of variance (p≤0.05) with LSD's post hoc when appropriate. Results: Participants' strength was evaluated using the one repetition maximum (1RM) test at BL and after each treatment phase. In the bench press, both RR doses exhibited significant enhancements compared to BL and PL, with weights being BL (69.6±39.7kg), PL (69.8±39.1kg), LD (72.2±41.1kg), and HD (73.4±41.4kg; p=0.001). Similarly, in the leg press, weights for both RR doses showed marked improvements over BL and PL, registering at BL (314.4±113.5kg), PL (326.2±117.0kg), LD (350.1±136.1kg), and HD (362.1±134.6kg; p&lt;0.001). Muscular endurance was further probed, with participants conducting three sets at 60% of their 1RM for both exercises. In the bench press, the HD treatment showed a significant edge over BL and PL, with weights being BL (42.5±22.9kg), PL (43.2±23.0kg), LD (43.8±23.1kg), and HD (44.7±23.6kg; p=0.007). In the leg press, both RR doses outperformed BL and PL, with weights being BL (188.6±68.2kg), PL (195.1±68.6kg), LD (209.1±80.2kg), and HD (218.6±79.1kg; p&lt;0.001). Regarding total lifting volume, both RR doses surpassed the BL measurements, with the HD regimen exceeding the PL. The volumes were BL (9792.7±4962.7kg), PL (11019.6±5389.2kg), LD (11805.1±5086.2kg), and HD (15344.8±10878.1kg; p&lt;0.001). During the bench press evaluations, a significant uptick in mean power was observed post-RR supplementation for both dosages when compared to BL and PL, with power outputs being BL (200.7±124.4W), PL (204.1±124.4W), LD (221.6±139.6W), and HD (230.5±145.9W; p=0.007). However, metrics such as peak power, average velocity, and the outcomes of the Wingate test remained statistically unchanged (p&gt;0.05). CONCLUSION: RR supplementation can enhance anaerobic performance in athletes, especially at higher doses. While it improved strength and endurance, some metrics, like peak power, remained unaffected. Further research is needed to understand RR's benefits fully. This study was self-funded, with the researchers covering all expenses. This approach ensures the research's independence from potential biases associated with external funding or grants. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Dryland Performance Tests Are Not Good Predictors of World Aquatics Points in Elite Male and Female Swimmers.

Background: Swim performance can be reliant on strength and power. Standardisation of swim performance in different events, distances, and sexes can be completed using World Aquatics points, allowing for ranking of swimmers. The aim of this retrospective cross-sectional study was to assess whether relationships between World Aquatics points and dryland markers of performance existed in male and female elite swimmers separately and combined. Methods: Dryland tests included Optojump® photoelectric cell countermovement jump, countermovement jump reach with a Vertec® system, standing broad jump using a tape measure, repetition maximum testing in the barbell back squat, barbell deadlift, and barbell bench press. Swim performance data and dryland test data on elite male (n = 38) and female (n = 20) Scottish swimmers from 2009-2017 were collected. Swim performance data were converted to World Aquatics federation points, and Bayesian linear regression analyses examined relationships between World Aquatics points and dryland performance tests: countermovement jump height (cm) using an Optojump® photoelectric cells system, countermovement jump height (cm) using a Vertec® device, standing broad jump distance (cm), relative strength (load lifted (kg) per kg of body mass) in the barbell bench press (kg/kg), barbell back squat (kg/kg), barbell deadlift (kg/kg). Results: The Bayesian estimates of change of World Aquatics points for a unit change in jump-based measures were: Optojump®-men = 0.6, women = 0.6, combined = 0.4; Vertec®-men = 4.3, women = -1.6, combined = 2.4; standing broad jump-men = 0, women = 0, combined = 0.4. Strength-based measures were: barbell back squat-men = 2.3, women = 22, combined = -2.5; barbell deadlift-men = -5; barbell bench press-men = 41.8. Conclusions: Dryland performance tests are not good predictors of World Aquatics points and should rather be used for assessing training quality and monitoring injury risks.

A Comparison of Subjective Estimations and Objective Velocities at Quantifying Proximity to Failure for the Bench Press in Resistance-Trained Men and Women.

Hickmott, LM, Butcher, SJ, and Chilibeck, PD. A comparison of subjective estimations and objective velocities at quantifying proximity to failure for the bench press in resistance-trained men and women. J Strength Cond Res 38(7): 1206-1212, 2024-The purpose of this study was to compare the accuracy of quantifying repetitions in reserve (RIR) in the bench press among 18 men and 18 women between 2 conditions: (a) subjective estimations and (b) objective velocities. Subjects performed 4 sessions over 10 days: (a) 1 repetition maximum (1RM) test; (b) repetition-to-failure test at 80% of 1RM; (c) 3 sets to failure at 80% of 1RM; and (d) 3 sets to failure at 75, 80, and 85% of 1RM. During sessions 2, 3, and 4, subjects verbally stated their perceived 4 and 2 RIR intraset, whereas average concentric velocity was recorded on all repetitions. The dependent variable for the subjective estimations condition was the difference between the actual number of RIR and the subject's subjective estimated number of RIR at the verbally stated 4 and 2 RIR. The dependent variable for the objective velocities condition was the difference between the actual number of RIR and the number of RIR calculated from the subject's baseline individualized last repetition average concentric velocity-RIR profile. Significance was set at p ≤ 0.05. Sessions 3 and 4 had significant ( p < 0.001) condition × set and condition × load interactions, respectively, at both 4 and 2 RIR. Objective velocities were significantly more accurate than subjective estimations on set 1 and set 2 at both RIRs during session 3 and for 75 and 80% of 1RM at both RIRs during session 4. Objective velocities exhibit significantly greater accuracy than subjective estimations at quantifying RIR during initial sets and lower loads.

Clinical, physical, and psychological outcomes among individuals with post COVID-19 syndrome with different functional status: a cross-sectional study

Introduction: post-COVID-19 syndrome or long COVID is a condition characterized by symptoms that persist after the disease's infection. Objective: to compare clinical, physical, and psychological outcomes among individuals with post COVID-19 syndrome with different levels of functional status after hospitalization for COVID-19. Methods: an observational, analytical, cross-sectional and with a quantitative approach with 75 individuals with post COVID-19 syndrome after hospitalization. Individuals underwent assessment of pulmonary function, six-minute walk test (6MWT), 1-minute sit and stand test (STS1), hand grip strength (HGS) and one repetition maximum test (1RM), Hospital Anxiety and Depression Scale (HADS), Short-Form Healthy Survey (SF-36) and Post-COVID Functional Scale (PCFS). Individuals were separated according to PCFS into two groups: low (LFL) and high (HFL) functional limitation (PCFS 1-2 and PCFS 3-4, respectively). Data regarding anthropometric and clinical characteristics, hospitalization history, and occupational activity were also collected. Results: individuals post COVID-19 syndrome with HFL presented worse score in the SF-36 in the functional capacity (p=0,01); pain (p=0,01), social aspects (p=0,01) and these individuals had a higher need for ICU admission (p=0,03) and prolonged hospitalization stays (p=0,04) compared to those with LFL. Conclusion: individuals with post COVID-19 syndrome that reported HFL exhibit poorer quality of life concerning the domains of functional capacity, pain, and social aspects when compared to those with LFL. Additionally, HFL individuals had a higher need for ICU admission and prolonged hospitalization stays

Effects of Resistance Training Overload Progression Protocols on Strength and Muscle Mass.

The aim of this study was to compare the effects of progressive overload in resistance training on muscle strength and cross-sectional area (CSA) by specifically comparing the impact of increasing load (LOADprog) versus an increase in repetitions (REPSprog). We used a within-subject experimental design in which 39 previously untrained young persons (20 men and 19 women) had their legs randomized to LOADprog and REPSprog. Outcomes were assessed before and after 10 weeks of training. Muscle strength was assessed using the one repetition maximum (1RM) test on the leg extension exercise, and the CSA of the vastus lateralis was assessed by ultrasonography. Both protocols increased 1RM values from pre (LOADprog: 52.90±16.32 kg; REPSprog: 51.67±15.84 kg) to post (LOADprog: 69.05±18.55 kg, REPSprog: 66.82±17.95 kg), with no difference between them (P+>+0.05). Similarly, both protocols also increased in CSA values from pre (LOADprog: 21.34±4.71 cm²; REPSprog: 21.08±4.62 cm²) to post (LOADprog: 23.53±5.41 cm², REPSprog: 23.39±5.19 cm²), with no difference between them (P+>+0.05). In conclusion, our findings indicate that the progression of overload through load or repetitions can be used to promote gains in strength and muscle hypertrophy in young men and women in the early stages of training.

Sex differences in fatiguability during single-joint resistance exercise in a resistance-trained population.

The primary aim of this study was to compare the fatiguability and acute recovery from a session of unilateral biceps curl exercise between habitually resistance-trained males and females. Twenty participants performed biceps curl one repetition maximum (1RM) and maximal voluntary contraction (MVC) testing of the elbow flexors. The exercise protocol consisted of four sets of unilateral biceps curls at 50% of the measured 1RM to volitional failure. MVC force and EMG activity of the elbow flexors were assessed following each set and during the recovery phase. The outcome variables compare the repetition volume, MVC strength loss, and EMG responses between males and females during the exercise and recovery phases. Across the exercise protocol, females completed significantly more repetitions compared to males (p < 0.01, d = 1.7) and lost significantly less strength across time (76% versus 69%, d = 0.48, p = 0.046). Additionally, females maintained a higher level of normalized EMG amplitude compared to males across the protocol (p = 0.035; d = 0.510). However, there were no sex differences in the strength (p = 0.562) or EMG (p = 0.607) responses during the recovery phase. In a resistance-trained population, females were able to perform a greater number of repetitions during the biceps curl exercise compared to their male counterparts at the same relative intensity of exercise. The ability of females to maintain a greater proportion of their maximal elbow flexor strength and muscle excitation during exercise suggests females can tolerate greater upper-body resistance exercise volume than males.

Validity of Using the Load-Velocity Relationship to Estimate 1 Repetition Maximum in the Back Squat Exercise: A Systematic Review and Meta-Analysis.

LeMense, AT, Malone, GT, Kinderman, MA, Fedewa, MV, and Winchester, LJ. Validity of using the load-velocity relationship to estimate 1 repetition maximum in the back squat exercise: a systematic review and meta-analysis. J Strength Cond Res 38(3): 612-619, 2024-The one repetition maximum (1RM) test is commonly used to assess muscular strength. However, 1RM testing can be time consuming, physically taxing, and may be difficult to perform in athletics team settings with practice and competition schedules. Alternatively, 1RM can be estimated from bar or movement velocity at submaximal loads using the minimum velocity threshold (MVT) method based on the load-velocity relationship. Despite its potential utility, this method's validity has yielded inconsistent results. The purpose of this systematic review and meta-analysis was to assess the validity of estimated 1RM from bar velocity in the back squat exercise. A systematic search of 3 electronic databases was conducted using combinations of the following keywords: "velocity-based training," "load-velocity profiling," "mean velocity," "mean propulsive velocity," "peak velocity," "maximal strength," "1RM," "estimation," "prediction," "back squat," and "regression." The search identified 372 unique articles, with 4 studies included in the final analysis. Significance was defined as a p level less than 0.05. A total of 27 effects from 71 subjects between the ages of 17-25 years were analyzed; 85.2% of effects were obtained from male subjects. Measured 1RMs ranged from 86.5 to 153.1 kg, whereas estimated 1RMs ranged from 88.6 to 171.6 kg. Using a 3-level random effects model, 1RM back squat was overestimated when derived from bar velocity using the MVT method (effect sizes [ES] = 0.5304, 95% CI: 0.1878-0.8730, p = 0.0038). The MVT method is not a viable option for estimating 1RM in the free weight back squat. Strength and conditioning professionals should exercise caution when estimating 1RM from the load-velocity relationship.

Differences in Lift Quality During the Barbell Back Squat When Using Perceived Recovery Status-Regulated Intrasession Recovery Compared With Standardized Recovery Intervals.

Wolfe, AA, Laurent, CM, Tolusso, DV, and Rinehart, AN. Differences in lift quality during the barbell back squat when using perceived recovery status-regulated intrasession recovery compared with standardized recovery intervals. J Strength Cond Res 38(3): 444-449, 2024-The current investigation examined kinetic differences between standardized and perceptually regulated rest internals during power-based resistance training. Recreationally resistance-trained men ( n = 7) and women ( n = 7) completed 3 training sessions. Session 1 consisted of barbell back squat (SQ) 1 repetition maximum (1RM) testing. Two counterbalanced subsequent sessions of perceptually regulated vs. standardized intrasession recovery for 5 sets of 6 repetitions of SQ at 80% 1RM were completed. Lift quality was assessed using a barbell accelerometer that measured concentric and eccentric power and force outputs for each repetition. In each set, subjects reported a rating of perceived exertion (RPE) followed by passive rest for either 2 minutes or a self-selected period using the Perceived Recovery Status (PRS) scale. For the self-selected session, when an individual reported a PRS at level "7," they were instructed to begin the next set. Data were analyzed using a 2 (session) × 5 (set) repeated-measures ANOVA with Bonferroni post hoc analyses performed when appropriate. No significant main effects or interactions were observed for any set quality metrics in the concentric phase or eccentric phase, except peak eccentric power ( p = 0.01). Post hoc analyses revealed a significant increase in peak eccentric power from set 1 to set 2 ( p = 0.003) only. Finally, no significant difference between self-selected vs. standardized work-to-rest strategies on RPE ( p = 0.547) was expressed. These data suggest perceptually regulated intrasession recovery selection yields equivalent lift quality as standardized rest recommendations. Therefore, PRS utilization may provide a more simplified and individualized method of between-set rest prescriptions.

Comparison of the Knee Extension Torque in the Maximum Voluntary Isometric Contraction and in the One Repetition Maximum Tests at Equivalent Angles

Comparison of the Knee Extension Torque in the Maximum Voluntary Isometric Contraction and in the One Repetition Maximum Tests at Equivalent Angles

The influence of flexibility on maximum strength performance in the overhead squat movement in crossfit™ practitioners

The objective of the present study was to evaluate the influence of ankle, hip and shoulder flexibility on relative maximum strength performance, through the one repetition maximum (1RM) test, in the overhead squat movement (OHS) in CrossFit ™ practitioners. 52 individuals of both sexes who practiced CrossFit ™ were investigated in two boxes based in the cities of Canoas and Gravataí, Rio Grande do Sul, Brazil. The results showed that general flexibility presents a positive, weak and non-significant correlation with the relative strength of OHS (ρ=0.0152; p=0.9159). Stratifying by joint and sex, for women, a weak, positive and non-significant correlation was found between relative OHS strength for the ankle joint (ρ=0.1556; p=0.4477) and weak, negative and non-significant correlations for the hip and shoulder joints (ρ=-0.0256, -0.0369; p=0.9008, 0.8579) respectively. For men, weak, positive and non-significant correlations were found in the ankle, hip and shoulder joints (ρ=0.0395, 0.3012, 0.2523; p=0.8480; 0.1348; 0.2136), respectively. Despite showing slightly greater positive associations for male individuals, linearity cannot be asserted between the variables analyzed.

Effects of progressive intensity resistance training on the impact of fibromyalgia: protocol for a blinded randomized controlled trial

BackgroundFibromyalgia guidelines indicate that exercise is critical in the management of fibromyalgia, and there is evidence that patients with fibromyalgia can perform resistance training at moderate and high intensities. However, despite the biological plausibility that progression of intensity provides greater benefit to individuals, no studies have compared different intensities (progressive versus constant intensities) of the same exercise in this population.ObjectiveTo compare the effect of 24 sessions of resistance training (progressive vs. constant intensity) on impact of fibromyalgia, sleep quality, anxiety, depression, pain, walking ability, and musculoskeletal capacity.MethodsA protocol for a blinded randomized controlled trial. The sample will be randomized into three groups: group 1 (progressive intensity, experimental), group 2 (constant intensity, control A), and group 3 (walking, control B). Group 1 will perform resistance training at moderate intensity (50% of maximum dynamic strength), previously determined by the 1 repetition maximum (1-RM) test in the proposed exercises. The strength of each individual will be reassessed every 4 weeks (by 1-RM) and the intensity of each exercise will be positively adjusted by 20% of the value observed in kg (i.e., first month 50%; second month 70%; third month 90% of the maximum dynamic strength). Group 2 will perform the same procedure, but the intensity will be maintained at 50% of the maximum dynamic strength throughout the treatment (i.e., constant intensity from the first to the third month). Group 3 will perform a 40-minute treadmill walk at low intensity, defined by a walking speed corresponding to 60-70% of the maximum heart rate, which we will control with a heart rate monitor. All groups will receive a 45-minute pain education session prior to the exercise program, covering the pathophysiologic mechanisms of chronic pain, strategies for coping with pain, avoiding hypervigilance, and deconstructing beliefs and myths about chronic pain.DiscussionThe results of the present study may help health care professionals adjust the intensity of resistance training and thus plan the most effective intervention (progressive or constant intensity) to reduce the impact of fibromyalgia on patients’ lives.Trial registrationBrazilian Registry of Clinical Trials (ReBEC) ID: RBR-9pbq9fg, date of registration: October 06, 2022.

THU512 Elevated Insulin Like Growth Factor Binding Protein 2 Levels Are Associated With Muscle Wasting And Increased Insulin Sensitivity In Cancer Patients

Abstract Disclosure: L. Caeiro: None. L.J. Anderson: None. H. Liu: None. K. Krumm: None. J.M. Garcia: None. Cancer-associated weight loss is a complex metabolic syndrome characterized by a loss of skeletal muscle mass and function. Insulin resistance is present in cancer but its role in cancer-related muscle wasting is poorly understood. Recent data from in vitro and animal models show that tumor-derived insulin-like growth factor binding protein (IGFBP)-2 can lead to skeletal muscle wasting and insulin resistance in cancer. We hypothesized that muscle mass and function would be inversely associated with IGFBP-2 levels and insulin resistance in circulation. IGFBP-2, physical function, body composition, insulin and glucose (to calculate HOMA-IR), quality of life (QOL), and cytokines were assessed in male cancer patients with (CWL, n=25) or without (CWS, n=47) weight loss. Physical Function was assessed by hand grip strength (HGS), stair climb power (SCP), and one repetition maximum (1RM) tests of the major muscle groups. Body composition was measured by bioimpedance (BIA) and CT scans and QOL by Karnofsky and ECOG scores. Blood samples were obtained after an overnight fast to measure IGFBP-2, insulin, glucose, interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) in plasma. CWL had higher plasma IGFBP2 levels (p = 0.01) and lower skeletal muscle index (SMI) (p = 0.03) and body mass index (BMI) (p = 0.007) when compared to CWS, but no differences were found with SCP, HGS, 1RM tests, or with HOMA-IR. IGFBP2 was negatively correlated with SMI (N = 65, R² = -.58, P = &amp;lt;0.001), BMI (N=73, R² = -.54, P = &amp;lt;0.001), CT-derived muscle mass (N = 48, R² = -.56, P = &amp;lt;0.001), BIA fat percent, (N = 25, R² = -.56, P = 0.005), 6 month weight change (N = 73, R² = -.27, P = 0.020), 12 month weight change (N = 73, R² = -.24, P = 0.044), insulin (N = 53, R² = -.48, P = &amp;lt;0.001) ,and HOMA IR (N = 53, R² = -.51, P = &amp;lt;0.001) and positively correlated with IL-6 (N = 72, R² = .33, P = 0.005) and TNF-α (N = 72, R² = .27, P = 0.021) in cancer patients. HOMA-IR was positively correlated with SMI (N = 31, R² = .39, P = 0.029), CT-derived muscle mass (N = 31, R² = .38, P = 0.036), and BIA fat percent (N = 21, R² = .62, P = 0.003). No association was found with IGFBP2 and QOL, SCP, HGS or the other functional parameters with exception of Knee Extension (N = 26, R² = .39, P = 0.049). In conclusion, cancer weight losing patients have increased IGFBP2 levels that were associated with muscle wasting, decreased fat mass, weight loss, and elevated IL-6 and TNF-α. HOMA-IR was negatively correlated with IGFBP2 and positively correlated with muscle mass. We postulate that a decrease in fat mass seen in weight-losing cancer patients leads to an increase in insulin sensitivity. More studies are needed to test this hypothesis and establish the role of IGFBP-2 as a mediator of muscle wasting in cancer. Presentation: Thursday, June 15, 2023

Physiological and Biochemical Adaptations to a Sport-Specific Sprint Interval Training in Male Basketball Athletes.

The present study compared the effects of incorporating traditional sprint interval training (SIT) or basketball-specific SIT (SSIT) into typical off-season training of male basketball players. Adaptations to and effect size (EF) of interventions on aerobic fitness [evaluated using Yo-Yo intermittent recovery test level-1 (Yo-Yo IR1)], change of direction [T-test (TT) and Illinois agility test (IAT)], vertical jump (VJ), standing long jump (SLJ), linear speed, maximal strength [one repetition maximum test in leg press (1RMLP)], and hormonal status were examined. Male athletes (age = 25.7 ± 2.0 years; height = 188.1 ± 7.9 cm; body mass = 85.9 ± 8.0 kg) were randomly assigned to one of three groups of SIT (n = 10): three sets of 10 × 15 sec all-out intervals with 1:1 recovery between bouts and a 3-min recovery between sets; SSIT (n = 10): the same intervals as SIT + basketball-specific ball drills while running; and CON (n = 10): two sessions per week of regular basketball technical and tactical drills. SIT and SSIT resulted in significant changes compared with baseline in maximal oxygen uptake (4.9%, ES = 2.22 vs. 6%, ES = 2.57), TT (-1.8%, ES =-0.46 vs. -2.7%, ES = -1.14), IAT (-4.5%, ES = -2.01 vs. -5.4%, ES = -1.93), VJ (7.5%, ES = 0.58 vs. 12%, ES = 0.95), linear sprint time (-2.9%, ES = -0.32 vs. -4.3%, ES = -0.69), Yo-Yo IR1 (18.5%, ES = 2.19 vs. 23.7%, ES = 2.56), serum testosterone (28%, ES = 1.52 vs. 29.7%, ES = 1.59), and cortisol (-6.53%, ES = -0.37 vs. -12.06%, ES = -0.64). Incorporating SIT and SSIT into typical off-season basketball training triggers adaptive mechanisms that enhance aerobic and anaerobic performance in male basketball players. The effect size values indicate more significant effects of SSIT than SIT in most physiological and sport-specific adaptations. Such a superior effect could be attributed to the more basketball-specific movement pattern of the SSIT. Such interventions can be used by the coaches and athletes for designing the training load and for better training adaptations throughout the training seasons and competition periods.

The relationships between ACTN3 rs1815739 and PPARA-α rs4253778 gene polymorphisms and athletic performance characteristics in professional soccer players

BackgroundCurrent research on athletic performance focuses on genetic variants that contribute significantly to individuals’ performance. ACTN3 rs1815739 and PPARA-α rs4253778 gene polymorphisms are variants frequently associated with athletic performance among different populations. However, there is limited research examining the pre-and post-test results of some variants of athletic performance in soccer players. Therefore, the presented research is to examine the relationships between the ACTN3 rs1815739 and PPARA-α rs4253778 gene polymorphisms and athletic performance improvement rates in adaptations to six weeks of training in elite soccer players using some athletic performance tests.MethodologyTwenty-two soccer players between the ages of 18 and 35 voluntarily participated in the study. All participants were actively engaged in a rigorous six-day-a-week training program during the pre-season preparation period. Preceding and following the training program, a battery of diverse athletic performance tests was administered to the participants. Moreover, Genomic DNA was extracted from oral epithelial cells using the Invitrogen DNA isolation kit (Invitrogen, USA), following the manufacturer’s protocol. Genotyping was conducted using real-time PCR. To assess the pre- and post-test performance differences of soccer players, the Wilcoxon Signed Rank test was employed.ResultsUpon analyzing the results of the soccer players based on the ACTN3 genotype variable, it was observed that there were no statistically significant differences in the SJ (Squat Jump), 30m sprint, CMJ (Counter Movement Jump), and DJ (Drop Jump) performance tests (p > 0.05). However, a statistically significant difference was identified in the YOYO IRT 2 (Yo-Yo Intermittent Recovery Test Level 2) and 1RM (One Repetition Maximum) test outcomes (YOYO IRT 2: CC, CT, and TT, p = 0.028, 0.028, 0.008, 0.000, respectively; 1RM: CC, CT, and TT, p = 0.010, 0.34, 0.001, respectively). Regarding the PPARA-α genotype variable, the statistical analysis revealed no significant differences in the SJ, 30m sprint, CMJ, and DJ performance tests (p > 0.05). Nevertheless, a statistically significant difference was observed in the YOYO IRT 2 and 1RM test results (YOYO IRT 2: CC, CG p = 0.001, 0.020; 1RM: CC, p = 0.000)ConclusionsThe current study demonstrated significant enhancements in only YOYO INT 2 and 1RM test outcomes across nearly all gene variants following the six-day-a-week training program. Other performance tests, such as the 30m sprint, SJ, CMJ, and DJ tests did not exhibit statistically significant differences. These findings contribute novel insights into the molecular processes involving PPARA-α rs4253778 and ACTN3 rs1815739 that underpin enhancements in endurance (YOYO INT 2) and maximal strength (1RM) aspects of athletic performance. However, to comprehensively elucidate the mechanisms responsible for the association between these polymorphisms and athletic performance, further investigations are warranted. It is thought that the use of field and genetic analyses together to support each other will be an important detail for athletes to reach high performance.