Repetition Maximum Test Research Articles

"NO LOAD" Resistance Training Promotes High Levels of Knee Extensor Muscles Activation-A Pilot Study.

The present article aims to compare electromyographic (EMG) activity of the knee extensors during traditional resistance training (TRT) and no load resistance training with or without visual feedback (NL-VF and NL-NF). Sixteen healthy men (age: 25.2 ± 3.6) volunteered to participate in the study. Participants visited the laboratory on three occasions involving: (1) a 10 repetition maximum test (10 RM test), (2) familiarization and (3) performance of knee extensions using TRT, NL-VF and NL-NF in a random order, with 10 min of rest between them. TRT involved the performance of a set to momentary muscle failure using the 10 RM load. NL-NF involved the performance of 10 repetitions with no external load, but with the intention to maximally contract the muscles during the whole set. NL-VF involved the same procedure as NL-NF, but a monitor was positioned in front of the participants to provide visual feedback on the EMG activity. Peak and mean EMG activity were evaluated on the vastus medialis (VM), vastus lateralis (VL) and rectus femoris (RF). Results: there were no significant differences in VM and VL peak EMG activity among different situations. There was a significant difference for peak EMG activity for RF, where TRT resulted in higher values than NL-VF and NL-NF (p < 0.05). Higher values of mean EMG activity were found for VM, VL and RF during TRT in comparison with both NL-VF and NL-NF. Conclusions: resistance training with no external load produced high levels of peak muscle activation, independent of visual feedback, but mean activation was higher during TRT. These results suggest that training with no external load might be used as a strategy for stimulating the knee extensors when there is limited access to specialized equipment. Although the clinical applications of no load resistance training are promising, it is important to perform long-term studies to test if these acute results will reflect in muscle morphological and functional changes.

Influence of exercise order on the number of repetitions in untrained teenagers.

Introduction: Prescription of resistance training (RT) is increasing among teenagers, requiring further studies to investigate the effects on this population. Objective: To examine the different orders on exercises sequence and its influence on the number of repetitions in teenager. Methods: Participated in the study 12 voluntarily male teenagers (14.91 ± 0.79 years, 1.69 ± 8.61 cm, 62.24 ± 7.26 kg) without experience in RT. After 48 hours of the last session of 10 repetitions maximum (10RM) test, subjects performed one of the four sequences of exercises in a counterbalanced crossover design. Four different sequences were also performed with a interval of 48 hours. All sequences were three sets of each exercise with 10RM load, with two-minute intervals between sets and exercises. The order of exercises was the sequence 1: bench press (BP), pulldown (PD), machine shoulder press (SP), biceps curl (BC) and triceps (TR); Sequence 2: TR, BC, SP, PD and BP; the sequence 3: Leg press (LP), leg extension (LE) and leg curl (LC); Sequence 4: LC, LE and LP. Results: Significant differences were observed (p &lt;0.05) in the total number of repetitions for the BP exercises, SP, BC and TR for the sequence of the upper limbs and for the lower limbs and the LP and LE exercises. Conclusion: The results suggest that the performance of the average number of repetitions for sessions conducted with RT intensity of 10RM in teenagers was influenced by the different kind of exercises in both upper and lower limbs.

The Effects Of Citrulline Malate Supplementation In Strength And Muscle Mass

L-citrulline (CIT) is a non-essential amino acid, found abundantly in watermelon, which has the ability to indirectly increase nitric oxide production by increasing arginine levels. A combination and the acute use of CIT with malate (intermediate of the Krebs cycle) has shown interesting results in the sports science literature, but the chronic effect of citrulline malate (CM) in the scientific literature is still unclear. PURPOSE: Investigate the chronic effects of citrulline malate supplementation in increasing strength and muscle mass in trained healthy adults. METHODS: A randomized, double-blind, crossover, placebo clinical study. Twenty four (25.96 ± 4.7 years) healthy adult men were randomly divided into 2 groups; citrulline malate group (CM= 12; 82.4±10.7kgs) or placebo group (PL = 12; 82.11±10,9kgs). The CM group received a sachet containing 6g of citrulline malate + 15g of maltodextrin and the PL group 6g of non-essential amino acids (NAAE) + 15g of maltodextrin. Supplementation was performed for 28 days (4 weeks) and included a wash-out week. After this week, there was an exchange of supplements in both groups. Before and after each supplementation, body composition (body weight, fat mass and muscle mass) by plethysmography (BodPod), and repetition maximum test (1RM) in the bench press were performed. Statistical analysis was performed using the covariance analysis model for crossover experiments, considering a significance level p<0.05. RESULTS: CM supplementation promoted an increase in total lean mass (67.28 ± 8.11kgs vs 67.77 ± 7.97kgs, p<0.005) in relation to placebo (67.83 ± 7.84kgs vs 67.43 ± 8.57kgs) (CM vs PL p<0.001), a decrease in total weight (CM 82.39 ± 10.72kgs vs 81.63 ± 9.98kgs and PL 82.11 ± 10.9kgs vs 82.08 ± 9.78kgs, CM vs PL p<0.05) and an increase in the final bench press (CM 37.95 ± 7.6kgs vs 41.55 ± 8.31kgs, p<0.05) in relation to placebo supplementation (38.26 ± 8.69kgs vs 40.08 ± 8.19kgs, p<0.05) (CM vs PL, p<0.01), regardless of the sequence in which the supplement was ingested. CONCLUSION: Supplementation of CM for 4 weeks proved to be effective in improve body composition (decrease in total weight and increase lean mass) and increased strength, without showing adverse effects, indicating a viable strategy for practitioners of resistance exercise.

Sagittal And Frontal Plane Joint Moments Of The Sumo Deadlift During Shod And Barefoot Conditions

Sumo style deadlifting has recently become more prevalent. Barefoot-style lifting has also become increasingly popular with claims such as increased force production and improved “grounding” of the foot. However, the biomechanics of sumo deadlifting while barefoot have not been examined. PURPOSE: To examine the effects on the hip, knee, and ankle joint moments during a sumo deadlift when comparing shod and barefoot conditions. METHODS: Ten subjects (27.3±3.5 yrs, 1.74±0.13m, 77.97±17.34kg) with minimum six months of deadlift experience (7.6±4.6 yrs), who were free from lower extremity injury, performed 1 repetition maximum (1RM; 137.7±43.0 kg) testing on day 1. This testing was performed in self-selected footwear. On day 2, a minimum of 72 hours later, subjects lifted 70% of their 1RM during a 3-dimensional analysis. Subjects performed one set of five continuous repetitions of a sumo deadlift in shod and barefoot conditions in randomized order. Five minutes of rest was given between sets. Marker data were collected using Qualisys Track Manager, sampling at 240Hz. Force data were collected using Bertec force plates, sampling at 1200Hz. Raw marker and force data were imported into Visual3D. Marker and force data were filtered using a fourth-order lowpass Butterworth filter at 8Hz. Peak internal sagittal and frontal plane joint moments of the hip, knee, and ankle were calculated during the concentric phase of each repetition. Peak vertical ground reaction force was measured during the concentric phase. RESULTS: No significant differences were detected in peak hip extension moment (p=0.855), hip abduction (p=0.288), knee extension (p=0.607), knee abduction (p=0.926), ankle plantarflexion (p=0.376), ankle eversion (p=0.739), or peak vertical ground reaction force (p=0.558). CONCLUSIONS: There is no evidence to suggest that the barefoot lifting style increases performance capabilities when lifting the same weight as in the shod condition. Additionally, there is no evidence to suggest that there is any increased risk in excess frontal plane joint moments during barefoot lifting. Future research should examine the 1RM capabilities in both shod and barefoot conditions to determine if differences exist during maximal compared to submaximal efforts.

Perception of changes in bar velocity in resistance training: Accuracy levels within and between exercises

Velocity-based training is a method used to monitor resistance-training programs based on repetition velocities measured with tracking devices. Since velocity measuring devices can be expensive and impractical, trainee's perception of changes in velocity (PCV) may be used as a possible substitute. Here, 20 resistance-trained males first completed 1 Repetition Maximum (RM) tests in the bench-press and squat. Then, in three counterbalanced sessions, participants completed four sets of eight repetitions in both exercises using 60%1RM (two-sessions) or 70%1RM. Starting from the second repetition, participants reported their PCV of each repetition as a percentage of the first repetition. Accuracy of PCV was calculated as the difference between PCV and actual changes in velocity measured with a linear-encoder. Three key findings emerged. First, the absolute error in the bench-press and squat was ≈5.8 percentage-points in the second repetition, and increased to 13.2 and 16.7 percentage-points, respectively, by the eighth repetition. Second, participants reduced the absolute error in the second 60%1RM session compared to the first by ≈1.7 in both exercises (p ≤ 0.007). Third, participants were 4.2 times more likely to underestimate changes velocity in the squat compared to the bench-press. The gradual increments in the absolute error suggest that PCV may be better suited for sets of fewer repetitions (e.g., 4–5) and wider velocity-loss threshold ranges (e.g., 5–10%). The reduced absolute error in the second 60%1RM session suggests that PCV accuracy can be improved with practice. The systematic underestimation error in the squat suggests that a correction factor may increase PCV accuracy in this exercise.

Ursolic acid has no additional effect on muscle strength and mass in active men undergoing a high-protein diet and resistance training: A double-blind and placebo-controlled trial.

Ursolic acid (UA) is thought to have an anabolic effect on muscle mass in humans. This study sought to compare the effects of UA and a placebo on muscle strength and mass in young men undergoing resistance training (RT) and consuming a high-protein diet. A clinical, double-blind, placebo-controlled trial was conducted for 8 weeks. The Control+RT group (CON n=12) received 400mg/d of placebo, and the UA+RT group (UA n=10) received 400mg/d of UA. Both groups ingested ~1.6g/kg of protein and performed the same RT program. Pre- and post-intervention, both groups were evaluated for anthropometric measures, body composition, food intake and muscle strength. Food intake remained unchanged throughout the study. Both groups showed significant increases in body weight (CON Δ: 2.12±0.47kg, p=0.001 vs. UA Δ: 2.24±0.67kg, p=0.009), body mass index (BMI) (CON Δ: 0.69±0.15kg/m2, p=0.001 vs. UA Δ: 0.75±0.23, p=0.011) and thigh circumference (CON Δ: 1.50±0.36, p=0.002 vs. UA Δ: 2.46±0.50cm, p=0.003 vs. UA 1.84±0.82cm, p=0.001), with differences between them. There was no difference in the arm, waist and hip circumferences. Both groups showed increases in muscle mass (CON Δ: 1.12±0.26, p=0.001 vs. UA Δ: 1.08±0.28kg, p=0.004), but there was no significant difference between them. Additionally, there were significant increases in the one repetition maximum test in the bench press and in the 10-repetition maximum test in the knee extension (CON Δ: 5.00±2.09, p=0.036 vs. UA Δ: 7.8±1.87, p=0.340 and CON Δ: 3.58±1.15, p=0.010 vs. UA Δ: 1.20±0.72, p=0.133), respectively, with no difference between them. Ursolic acid had no synergic effect on muscle strength and mass in response to RT in physically active men consuming a high-protein diet. RBR-76tbqs.

The Acute Effects of External Compression With Blood Flow Restriction on Maximal Strength and Strength-Endurance Performance of the Upper Limbs.

The main goal of the present study was to evaluate the acute effects external compression with blood flow restriction (BFR) at 100 and 150% of full arterial occlusion pressure (AOP) on maximal strength and strength-endurance performance during the bench press (BP) exercise. The study included 12 strength-trained male subjects (age = 23.2 ± 2.66 years; body mass = 75.3 ± 6.33 kg; height = 179.1 ± 3.82 cm), experienced in resistance training (5.7 ± 2.93 years). During the experimental sessions in a randomized crossover design, the subjects performed a 1 repetition maximum (1RM) test and three sets of the BP using 60% 1RM to failure with three different conditions: without BFR (NO-BFR); BFR with a pressure of 100% AOP (BFR100); and BFR with a pressure of 150% AOP (BFR150). The differences between the NO-BFR, BFR100, and BFR150 conditions were examined using repeated measures ANOVA. The ANOVA indicated significant main effect for condition in 1RM, number of performed repetitions (REP), and time under tension (TUT) (p < 0.01). Post hoc analyses for the main effect indicated significant increases in 1RM (p < 0.01; 95.00 ± 15.37 vs 91.87 ± 15.99), REP (p < 0.01; 17.56 ± 3.36 vs 15.67 ± 5.24), and TUT (p < 0.01; 32.89 ± 6.40 vs 28.72 ± 6.18) for the BFR150 condition compared to NO-BFR. Furthermore, significant increases in REP (p = 0.03; 17.56 ± 3.36 vs 16.47 ± 4.01) and TUT (p = 0.03; 32.89 ± 6.40 vs 30.00 ± 6.45) were observed for the BFR150 condition compared to the BFR100. The results of the present study indicate that high external compression increases maximal strength evaluated by the 1RM test, as well as endurance performance during three sets of the BP exercise.

Moderate/high resistance exercise is better to reduce blood glucose and blood pressure in middle-aged diabetic subjects

Type 2 diabetes (T2D) main feature is insulin resistance. Hypertension is a comorbidity linked to T2D. Resistance exercise (RE) is an important non-pharmacological tool to contribute to managing blood glucose and blood pressure (BP), but there is not a common sense about acute effects. The aim of this study was to evaluate the acute physiological effects after two different RE sessions using different intensities at middle-aged hypertensive T2D subjects. There were 40 middle-aged men (20 nondiabetics; 20 diabetics), who underwent an exercise protocol with the same volume at 60% or 75% of the one maximum repetition test (1RM), consisting in: bench press, triceps pulley, rowing machine, barbell curl, lateral raise with dumbbells and barbell squat. Physiological changes were evaluated through BP, glycemia, creatine kinase, lactate dehydrogenase, C reactive protein (C-RP), testosterone and cortisol.For non-diabetics, both intensities promoted blood glucose uptake (8.2% to 11.1%, p&lt;0.05), and only the 75%1RM session induced blood glucose uptake in 5.7% in the diabetics. Post-exercise hypotension was significant after RE at 75%1RM for systolic BP (SBP) and after both intensities for diastolic BP (DBP) in non-diabetics, while the SBP and DPB reduced after both intensities for diabetics. RE at 75%1RM resulted in better blood glucose uptake, and both intensities reduced the BP in diabetic subjects. After 75%1RM there was a higher indirect muscle damage result. The alterations in hormones, C-RP, and indirect muscle damage markers indicated an adequate acute anabolic recovery with no significant inflammation in both intensities. Acute RE at 60%1RM or 75%1RM can used as an extra tool to manage both pathologic conditions.

Moderate/high resistance exercise is better to reduce blood glucose and blood pressure in middle-aged diabetic subjects

Type 2 diabetes (T2D) main feature is insulin resistance. Hypertension is a comorbidity linked to T2D. Resistance exercise (RE) is an important non-pharmacological tool to contribute to managing blood glucose and blood pressure (BP), but there is not a common sense about acute effects. The aim of this study was to evaluate the acute physiological effects after two different RE sessions using different intensities at middle-aged hypertensive T2D subjects. There were 40 middle-aged men (20 nondiabetics; 20 diabetics), who underwent an exercise protocol with the same volume at 60% or 75% of the one maximum repetition test (1RM), consisting in: bench press, triceps pulley, rowing machine, barbell curl, lateral raise with dumbbells and barbell squat. Physiological changes were evaluated through BP, glycemia, creatine kinase, lactate dehydrogenase, C reactive protein (C-RP), testosterone and cortisol.For non-diabetics, both intensities promoted blood glucose uptake (8.2% to 11.1%, p&lt;0.05), and only the 75%1RM session induced blood glucose uptake in 5.7% in the diabetics. Post-exercise hypotension was significant after RE at 75%1RM for systolic BP (SBP) and after both intensities for diastolic BP (DBP) in non-diabetics, while the SBP and DPB reduced after both intensities for diabetics. RE at 75%1RM resulted in better blood glucose uptake, and both intensities reduced the BP in diabetic subjects. After 75%1RM there was a higher indirect muscle damage result. The alterations in hormones, C-RP, and indirect muscle damage markers indicated an adequate acute anabolic recovery with no significant inflammation in both intensities. Acute RE at 60%1RM or 75%1RM can used as an extra tool to manage both pathologic conditions.

Intensity Thresholds and Maximal Lactate Steady State in Small Muscle Group Exercise.

The aim of our study is to determine the first (LTP1) and the second (LTP2) lactate turn points during an incremental bicep curl test and to verify these turn points by ventilatory turn points (VT1 and VT2) and constant-load exercise tests. Twelve subjects performed a one-arm incremental bicep curl exercise (IET) after a one repetition maximum (1RM) test to calculate the step rate for the incremental exercise (1RM/45). Workload was increased every min at a rate of 30 reps/min until maximum. To verify LTPs, VT1 and VT2 were determined from spirometric data, and 30 min constant-load tests (CL) were performed at 5% Pmax below and above turn points. Peak load in IET was 5.3 ± 0.9 kg (Lamax: 2.20 ± 0.40 mmol·L−1; HRmax: 135 ± 15 b·min−1; VO2max: 1.15 ± 0.30 L·min−1). LTP1 was detected at 1.9 ± 0.6 kg (La: 0.86 ± 0.36 mmol·L−1; HR 90 ± 13 b·min−1; VO2: 0.50 ± 0.05 L·min−1) and LTP2 at 3.8 ± 0.7 kg (La: 1.38 ± 0.37 mmol·L−1; 106 ± 10 b·min−1; VO2: 0.62 ± 0.11 L·min−1). Constant-load tests showed a lactate steady-state in all tests except above LTP2, with early termination after 16.5 ± 9.1 min. LTP1 and LTP2 could be determined in IET, which were not significantly different from VT1/VT2. Constant-load exercise validated the three-phase concept, and a steady-state was found at resting values below VT1 and in all other tests except above LTP2. It is suggested that the three-phase model is also applicable to small muscle group exercise.

Acute effect of sodium bicarbonate supplementation by resistant training practices

Currently, the use of sodium bicarbonate (SB) as an ergogenic supplement has been linked to improved performance in several high-intensity and short time interval modalities because it is a natural buffer of the body fluids of the human body. This study aimed to evaluate the acute effect of SB supplementation on muscle strength endurance of resistance training practitioners. Crossover clinical trial, placebo-controlled (PL), and single-masked, included 10 trained adult men. The maximum repetition (1RM) and exhaustion tests with 80% 1RM were performed in the extensor chair and direct thread. In all sessions, the volunteers were verbally stimulated, the total maximum repetitions in the exercises and the blood lactate concentration were measured. SB was supplemented at a dose of 0.3 g/kg body mass. Statistical analysis was performed using SPSS version 25.0. The Shapiro–Wilk test was used to evaluate the normality of the data, and the Student’s t-test was used for independent and paired samples. The size of the Cohen’s effect was calculated, and the significance level was set at p&lt;0.05. Comparing the supplements, no significant differences were found in all variables tested. However, when comparing pretest and posttest periods, significant differences were found between lactate concentrations, with considerably large effect sizes (&gt; 1.00). SB supplementation by endurance training practitioners induces blood alkalosis, which reduces fatigue and possibly improves muscle strength endurance. Keywords: resistance exercise, ergogenic, metabolic acidosis, muscular fatigue, performance.

Resistance training with blood flow restriction: Impact on the muscle strength and body composition in people living with HIV/AIDS

The aim of the study was to compare the impact of 12-week resistance training with blood flow restriction (GRTBFR) versus, traditional resistance training (GTRT) and non-training on the muscle strength and body composition HIV/AIDS participants. Muscle strength was tested at baseline, and on the 6th, 21st and 36th training sessions, using maximal repetition test. Pre- and post-intervention body composition changes were measured by dual-energy X-ray absorptiometry. Resistance training was undertaken three times a week comprising bilateral elbow extension and flexion exercises, unilateral flexion and bilateral knee extension. Changes in strength and body composition (pre- and post-intervention) between groups were evaluated by mixed models of repeated measures, and by paired and unpaired comparisons, considering the Effect Size. All groups were similar at baseline for muscle strength and body composition. Post-intervention, the training groups showed similar, statistically significant increases in muscle strength (GRTBFR=25.7–57.4%; GTRT=24.5–52.3%) and skeletal muscle tissue (GRTBFR=8.4%; GTRT=8.3%). There was also a significant change in body fat (p=0.023–0.043), with significant effect sizes for strength and skeletal muscle tissue (0.41–2.27), respectively. These results suggest that both resistance training interventions promoted muscle hypertrophy, body fat reduction and positive impact on muscle strength in people living with HIV/AIDS. Resistance training with blood flow restriction proved to be an effective alternative to include patients with marked physical weakness, unable to engage in regular strength training programme. ClinicalTrials.gov identifier: NCT02783417.

The effect of static passive stretching on a bench press, in one maximum repetition test performance, is independent of the level of flexibility

Objective: The aim of this study was to investigate at different levels of flexibility the influence of static passive stretching on bench press one maximum repetition test.&#x0D; Method: Eleven men (26.09 ± 4.2 years, 81.69 ± 13.94 kg, 1.70 ± 0.05 m) were evaluated in flexibility using Flexitest and goniometry test classified according to their flexibility levels (small and upper middle levels) and joint range of motion (deficit levels), as well as performed the one maximum repetition test in the following experimental protocols: without previous stretching and with stretching 10, 20 and 60 seconds before the test.&#x0D; Results: The results indicate that 64% demonstrated a low level of flexibility and 36% with a higher average level. In both, there was no significant difference in load: A0s (72.43 ± 21.10Kg vs 66.25 ± 19.02Kg); A10s (72.29 ± 20.25Kg vs 67.25 ± 20.35Kg); A20s (73.43 ± 20.78Kg vs 67.75 ± 18.23Kg) and A60s (73.29 ± 19.35Kg vs 68 ± 19.25Kg). ANOVA for repeated measures showed that no significantly different the maximum strength between groups the protocols of static passive stretching tested.&#x0D; Conclusion: It was concluded that passive static stretching times lower than 60 seconds, in accordance with the current recommendations, do not interfere in the neuromuscular performance of men in the one maximum repetition test, in the bench press independent of their level of flexibility.

The effect of self myofascial release and static stretching on the antagonist muscles before agonist performance

Objective: the aim of this study was to compare differences in volume load, total repetition performed and rating of perceived exertion between static stretching and self-myofascial release on antagonist muscles.&#x0D; Methods: Eighteen recreationally trained men (23.4 ± 3.3 years; 80.7 ± 11.1 kg; 1.76 ± 0.06 cm) performed 10 repetitions maximum test and retest in the leg extension exercise on the first two visits. Then, three experimental sessions were conducted in a random order, in which two consisted of self-myofascial release and static stretching on hamstrings, and the other was used as a control.&#x0D; Results: significant higher repetitions were performed in the third set of static stretching when compared to control protocol. Additionally, significant reductions in total repetitions performed were observed only in the control session. No significant differences were noticed in the volume load of leg extension and rating of perceived exertion between protocols.&#x0D; Conclusion: self-myofascial release and static stretching performed before a session in the antagonist muscles can maintain repetitions performance by optimizing recovery between sets and reducing fatigue of agonist muscle.

β-Alanine and l-histidine supplementation associated with combined training increased functional capacity and maximum strength in heart failure rats.

What is the central question of the study? Does β-alanine with l-histidine supplementation associated with endurance and strength training improve echocardiographic parameters, functional capacity, and maximum strength in rats with chronic heart failure? What is the main finding and its importance? β-Alanine with l-histidine supplementation associated with endurance and strength training increased functional capacity and maximum strength through increasing exercise capacity peripherally but did not affect echocardiographic parameters in rats with chronic heart failure. Combined training (CT) has been associated with positive responses in the clinical status of patients with chronic heart failure (CHF). Other non-pharmacological tools, such as amino acid supplementation, may further enhance its adaptation. However, the effects of β-alanine and l-histidine supplementation in CHF remain unclear. In the present study, the aim was to test whether supplementing carnosine precursors with CT could give improved responses in the functional capacity and echocardiographic variables of rats with CHF. Twenty-four Wistar rats, were submitted to myocardial infarction and allocated to three groups: animals with CHF kept in sedentary conditions (SED, n=8), animals with CHF submitted to CT in strength and aerobic exercise supplemented with placebo (CT-P, n=8) and animals with CHF submitted to CT in strength and aerobic exercise supplemented with β-alanine and l-histidine (CT-S, n=8). The trained animals were submitted to a strength protocol three times per week with intensity of 65-75% of one repetition maximum test. Aerobic training was conducted two times per week (50min, 15mmin-1 ). The supplemented group received β-alanine and l-histidine orally (each 250mgkg-1 day-1 ). No changes in echocardiographic and morphological parameters were found among the groups (P>0.05). Functional capacity, Δ and maximum strength were higher in CT-P than in SED and even higher in CT-S than in CT-P (P<0.01). The CT was able to improve functional capacity, but the supplementation was shown to enhance these parameters even further in the CHF rats. We conclude that the increase in functional capacity and strength gained through CT and supplementation were associated with the improvement in peripheral parameters with no changes in cardiac variables.

The Importance of Lower Body Strength and Power for Future Success in Professional Men’s Basketball

Heavy resistance exercise is often prescribed for collegiate basketball players to enhance game performance, but few data are available concerning the transference of lower body strength and power to the opportunity to play professionally after college. This study investigated if lower body muscular power and strength measures obtained during the barbell squat are related to future professional playing opportunities. The data was collected over a seven year period from a collegiate men’s basketball program (n=37; X±SD, age=20.0±1.4 yrs, hgt=1.98±0.09 m, bw=94.5±11.8 kg). Lower body strength was determined from 1 repetition maximum (1RM) tests of the parallel high-bar squat. Maximum lower body squat power was determined from speed squat testing across a load spectrum (30-90% 1RM) while an external tethered dynamometer or a 3-D video motion capture system quantified barbell power. Repeated measures ANOVA with Tukey’s HSD post hoc, Spearman ρ correlations, and Cohen’s D effect sizes were used to analyze the results. Subjects who subsequently played in the NBA or in professional leagues elsewhere had greater lower body strength and power. This was mainly attributed to their greater body mass, since strength and power relative to body mass was not different between the groups. Even without statistically significant differences, effect sizes consistently indicated moderate to large differences between the NBA and other professional groups when compared to those who did not play professionally. Regardless, lower body strength and power were related to post-collegiate playing opportunities, with greater values related to higher levels of professional play.

The Time Course of Changes in Neuromuscular Responses During the Performance of Leg Extension Repetitions to Failure Below and Above Critical Resistance in Women.

Dinyer, TK, Byrd, MT, Succi, PJ, and Bergstrom, HC. The time course of changes in neuromuscular responses during the performance of leg extension repetitions to failure below and above critical resistance in women. J Strength Cond Res 36(3): 608-614, 2022-Critical resistance (CR) is the highest sustainable resistance that can be completed for an extended number of repetitions. Exercise performed below (CR-15%) and above (CR+15%) CR may represent 2 distinct intensities that demonstrate separate mechanisms of fatigue. Electromyography (EMG) and mechanomyography (MMG) have been used to examine the mechanism of fatigue during resistance exercise. Therefore, the purposes of this study were to (a) compare the patterns of responses and time course of changes in neuromuscular parameters (EMG and MMG amplitude [AMP] and mean power frequency [MPF]) during the performance of repetitions to failure at CR-15% and CR+15% and (b) identify the motor unit activation strategy that best describes the fatigue-induced changes in the EMG and MMG signals at CR-15% and CR+15%. Ten women completed one repetition maximum (1RM) testing and repetitions to failure at 50, 60, 70, and 80% 1RM (to determine CR), and at CR-15% and CR+15% on the leg extension. During all visits, EMG and MMG signals were measured from the vastus lateralis. There were similar patterns of responses in the neuromuscular parameters, and time-dependent changes in EMG AMP and EMG MPF, but not MMG AMP or MMG MPF, during resistance exercise performed at CR-15% and CR+15% (p < 0.05). The onset of fatigue occurred earlier for EMG AMP, but later for EMG MPF, during repetitions performed at CR+15% compared with those performed at CR-15%. Thus, resistance exercise performed below and above CR represented 2 distinct intensities that were defined by different neuromuscular fatigue mechanisms but followed similar motor unit activation strategies.

The Effect of Resistance Exercise Movement Tempo on Psychophysiological Responses in Novice Men.

Tavares, VDdO, Agrícola, PMD, Nascimento, PHD, Oliveira Neto, L, Elsangedy, HM, and Machado, DGS. The effect of resistance exercise movement tempo on psychophysiological responses in novice men. J Strength Cond Res 34(5): 1264-1273, 2020-This study aimed to compare the effects of movement tempo in resistance exercise (RE) on psychophysiological responses in novice men. Seventeen novice men (24.5 ± 3.2 years; 79.3 ± 8.22 kg; 1.76 ± 0.06 m) performed the 10 repetition maximum (10RM) test for bench press and knee extension in 2 sessions (test-retest) and 2 RE training sessions with different movement tempos in a random and counterbalanced order (4 sets of 10 repetitions). The low tempo RE (LTRE) session was performed using 50% 10RM with 3-0-3-0 seconds (concentric, pause, eccentric, and pause, respectively). The moderate tempo RE (MTRE) session was performed using 80% 10RM with 1-0-1-0 seconds (concentric, pause, eccentric, and pause, respectively). Affective valence (Feeling Scale), perceived activation (FAS), attentional focus, and ratings of perceived exertion (Borg 6-20) were reported after each set. A two-way analysis of variance with repeated measures showed only a significant main effect of the set (all ps < 0.05), indicating changes between sets but not between LTRE and MTRE. In addition, a paired-samples t-test did not find significant differences between LTRE and MTRE, on average, in any psychophysiological responses (all ps > 0.16). Thus, for the protocol tested, there is no psychophysiological advantage to using either LTRE or MTRE in novice men. From a practical perspective, for psychophysiological responses, the present results suggest that it is up to the trainer/coach to decide which RE movement tempo to use, which will depend on the purpose of the training period, specificity, client tolerance of and preference for exercise intensity, and movement tempo.

Impact of Fat Grip Attachments on Muscular Strength and Neuromuscular Activation During Resistance Exercise.

Krings, BM, Shepherd, BD, Swain, JC, Turner, AJ, Chander, H, Waldman, HS, McAllister, MJ, Knight, AC, and Smith, JW. Impact of fat grip attachments on muscular strength and neuromuscular activation during resistance exercise. J Strength Cond Res 35(2S): S152-S157, 2021-The purpose of this study was to examine the acute effects of Fat Gripz (FG) on muscular activation and strength. Resistance trained men (n = 15; age = 22.4 ± 2.3 years; mass = 83.2 ± 11.1 kg) performed 2 experimental trials in a randomized order. Subjects completed 1 repetition maximum (1RM) testing with an Olympic barbell (OB) and with FG attached to an OB during the exercises of deadlift, bent-over row, upright row, concentration curl, and completed maximum repetitions of pull-ups until failure. Surface electromyography (EMG) was used to measure muscle activity from 8 upper extremity muscles (trapezius, medial deltoid, biceps brachii, triceps brachii, flexor carpi radialis, flexor carpi ulnaris, extensor carpi radialis, and extensor carpi ulnaris), while performing maximal voluntary isometric contractions during 1RM trials and while performing maximum number of pull-ups. When using the FG, 1RM strength was significantly decreased for each exercise, and the maximal number of pull-ups completed was significantly lower. Electromyography muscle activity was significantly increased in the forearm and shoulder muscles, but significantly decreased in the upper arm muscles with the use of FG during deadlift, bent-over row, and pull-ups. However, there were no differences for EMG activity for upright row and concentration curl. Differences in maximal strength, pull-up performance, and EMG activity with FG use may be due to the different muscle length positions. Although FG training may increase neuromuscular activation, decrements in muscular strength may result in prescribing low training loads that may not be ideal for building muscular strength.

Back Squat vs. Hip Thrust Resistance-training Programs in Well-trained Women.

The study compared the effects of back squat (BS) and hip thrust (HT) exercises on muscle strength and hypertrophy in well-trained women. Twenty-two participants were divided in two groups: BS group (n=12, 26.4±1.32 years, 171.8±3.79 cm, and 69.5±4.9 kg) performed the BS exercise and HT group (n=10, 27.5±1.42 years, 170.8±4.4 cm, 67.5±4.7 kg) performed the HT exercise. Training was performed for 12 weeks. Before and after the training period, participants were assessed for quadriceps femoris and gluteus maximus muscle thickness (MT) and 1 repetition maximum (1RM) test on the BS and HT. Both groups significantly increased hip extensors MT and HT 1RM; however, the improvements in BS group were higher than in HT group on quadriceps femoris (12.2% for BS and 2% for HT, P<0.001) and gluteus maximus MT (9.4% for BS and 3.7% for HT, P=0.001) and BS 1 RM (35.9% for BS and 4.3% for HT, P<0.001). BS was more efficient than HT, since it resulted in greater muscle hypertrophy of the quadriceps femoris and gluteus maximus, increases in BS 1RM and similar increases in HT.