Acute physiological and psychological responses during an incremental treadmill test wearing a new upper-body sports garment with elastomeric technology

Background: The use of elastomeric technology in sports garments is increasing in popularity; however, its specific impact on physiological and psychological variables is not fully understood. Thus, we aimed to analyze the physiological (muscle activation of the pectoralis major, triceps brachii, anterior deltoid, and rectus abdominis, capillary blood lactate, systolic and diastolic blood pressure, and heart rate) and psychological (global and respiratory rating of perceived exertion [RPE]) responses during an incremental treadmill test wearing a new sports garment for the upper body that incorporates elastomeric technology or a placebo garment. Methods: Eighteen physically active young adults participated in two randomized sessions, one wearing the elastomeric garment and the other wearing a placebo. Participants performed in both sessions the same treadmill incremental test (i.e., starting at 8 km/h, an increase of 2 km/h each stage, stage duration of 3 min, and inclination of 1%; the test ended after completing the 18 km/h Stage or participant volitional exhaustion). The dependent variables were assessed before, during, and/or after the test. Nonparametric tests evaluated differences. Results: The elastomeric garment led to a greater muscle activation (p < 0.05) in the pectoralis major at 16 km/h (+33.35%, p = 0.01, d = 0.47) and 18 km/h (+32.09%, p = 0.02, d = 0.55) and in the triceps brachii at 10 km/h (+20.28%, p = 0.01, d = 0.41) and 12 km/h (+34.95%, p = 0.04, d = 0.28). Additionally, lower lactate was observed at the end of the test (-7.81%, p = 0.01, d = 0.68) and after 5 min of recovery (-13.71%, p < 0.001, d = 1.00) with the elastomeric garment. Nonsignificant differences between the garments were encountered in the time to exhaustion, cardiovascular responses, or ratings of perceived exertion. Conclusion: These findings suggest that elastomeric garments enhance physiological responses (muscle activation and blood lactate) during an incremental treadmill test without impairing physical performance or effort perception.

Concurrent validation of the resistance intensity scale for exercise for monitoring velocity-based training with elastic bands

The aim was to evaluate the concurrent validity and reliability of the Resistance Intensity Scale for Exercise [RISE], which uses verbal descriptors, to quantify the intensity in velocity-based training with elastic bands. Eighteen trained volunteers performed parallel squats at maximum speed at 40%, 55%, 70%, and 85%1RM in four sessions, two for familiarization and two for reliability. Each set was stopped at a 10% intra-set velocity loss. Participants reported the perceived effort (easy-low-moderate-hard-maximal) at the first and last repetition. The concurrent validation was conducted with external load (i.e., mean propulsive velocity, weight, repetitions, and maximum power) and internal load parameters (i.e., heart rate). Participants' relative strength was calculated to assess its influence on the dependent variable. Acceptable concurrent validity and reliability (ICC>0.77, CV<21%) were observed, with the perceived effort being appropriate to differentiate between intensities and not being influenced by the participants' relative strength (p = 0.88). A categorical linear regression showed significant (p < 0.001) associations between the RISE scores and the weight, repetitions, and mean propulsive velocity (r = 0.43-0.63). The findings certify the usefulness of the perceived exertion for quantifying the intensity during velocity-based training with elastic bands. The perceived exertion of the first and last repetition favors a proper dosage of the training load.

Dietary supplementation habits in international natural bodybuilders during pre-competition

Bodybuilding is characterized by high-rates of sport supplementation. This is the first study to compare the supplementation patterns of winners (WB) and non-winners (NWB) among international natural bodybuilders during contest preparation. Fifty-six natural bodybuilders (5 women) (age = 28.85 ± 8.03 years; final body mass = 71.50 ± 10.28 kg), 19 WB (athletes who had achieved victory in an official natural bodybuilding championship at least once) and 37 NWB (athletes who never achieved victory), from 18 countries (55.36% from Spain) responded to this cross-sectional online survey related to their nutritional habits, strategies and supplementation practices. WB were significantly older (p = 0.024), completed more competitive seasons (p = 0.027) and participated in more competitions in the last contest year (p = 0.011). There were no significant differences between WB and NWB for years training for bodybuilding (p = 0.055), weeks of dieting for competition (p = 0.392), and body weight at the start (p = 0.553) and end (p = 0.330) of the season. Beverage and supplement consumption, purchasing patterns, and information sources did not differ between groups (p > 0.05). In conclusion, natural bodybuilding WB tended to be older and had more competitive experience, but shared similar supplementation protocols to NWB. Athletes' supplementation patterns were influenced by different sources of information. However, these natural bodybuilders mainly purchased their supplements through the internet without guidance from a coach or dietitian.

A new sports garment with elastomeric technology optimizes physiological, mechanical, and psychological acute responses to pushing upper-limb resistance exercises

This study aimed to compare the mechanical (lifting velocity and maximum number of repetitions), physiological (muscular activation, lactate, heart rate, and blood pressure), and psychological (rating of perceived exertion) responses to upper-body pushing exercises performed wearing a sports elastomeric garment or a placebo garment. Nineteen physically active young adults randomly completed two training sessions that differed only in the sports garment used (elastomeric technology or placebo). In each session, subjects performed one set of seated shoulder presses and another set of push-ups until muscular failure. The dependent variables were measured immediately after finishing the set of each exercise. Compared to the placebo garment, the elastomeric garment allowed participants to obtain greater muscular activation in the pectoralis major (push-ups: p = 0.04, d = 0.49; seated shoulder press: p < 0.01, d = 0.64), triceps brachialis (push-ups, p < 0.01, d = 0.77; seated shoulder press: p < 0.01, d = 0.65), and anterior deltoid (push-ups: p < 0.01, d = 0.72; seated shoulder press: p < 0.01, d = 0.83) muscles. Similarly, participants performed more repetitions (push-ups: p < 0.01; d = 0.94; seated shoulder press: p = 0.03, d = 0.23), with higher movement velocity (all p ≤ 0.04, all d ≥ 0.47), and lower perceived exertion in the first repetition (push-ups: p < 0.01, d = 0.61; seated shoulder press: p = 0.05; d = 0.76) wearing the elastomeric garment compared to placebo. There were no between-garment differences in most cardiovascular variables (all p ≥ 0.10). Higher diastolic blood pressure was only found after the seated shoulder press wearing the elastomeric garment compared to the placebo (p = 0.04; d = 0.49). Finally, significantly lower blood lactate levels were achieved in the push-ups performed wearing the elastomeric garment (p < 0.01; d = 0.91), but no significant differences were observed in the seated shoulder press (p = 0.08). Overall, the findings of this study suggest that elastomeric technology integrated into a sports garment provides an ergogenic effect on mechanical, physiological, and psychological variables during the execution of pushing upper-limb resistance exercises.

Long-Term Effects of Microfiltered Seawater and Resistance Training with Elastic Bands on Hepatic Parameters, Inflammation, Oxidative Stress, and Blood Pressure of Older Women: A 32-Week, Double-Blinded, Randomized, Placebo-Controlled Trial

The bulk of research on microfiltered seawater (SW) is based on its short-term effects. However, the long-term physiological adaptations to combining SW and resistance training (RT) are unknown. This study aimed to analyse the impact of an RT program using elastic bands combined with SW intake on hepatic biomarkers, inflammation, oxidative stress, and blood pressure in post-menopausal women. Ninety-three women voluntarily participated (age: 70 ± 6.26 years; body mass index: 22.05 ± 3.20 kg/m2; Up-and-Go Test: 6.66 ± 1.01 s). RT consisted of six exercises (32 weeks, 2 days/week). Nonsignificant differences were reported for hepatic biomarkers except for a reduction in glutamic-pyruvic transaminase (GPT) in both RT groups (RT + SW: p = 0.003, ES = 0.51; RT + Placebo: p = 0.012, ES = 0.36). Concerning oxidative stress, vitamin D increased significantly in RT + SW (p = 0.008, ES = 0.25). Regarding inflammation, interleukin 6 significantly decreased (p = 0.003, ES = 0.69) in RT + SW. Finally, systolic blood pressure significantly decreased in both RT groups (RT + placebo: p < 0.001, ES = 0.79; RT + SW: p < 0.001, ES = 0.71) as did diastolic blood pressure in both SW groups (RT + SW: p = 0.002, ES = 0.51; CON + SW: p = 0.028, ES = 0.50). Therefore, RT + SW or SW alone are safe strategies in the long term with no influences on hepatic and oxidative stress biomarkers. Additionally, SW in combination with RT positively influences vitamin D levels, inflammation, and blood pressure in older women.

Water-Based Exercise in Patients With Nonspecific Chronic Low-Back Pain: A Systematic Review With Meta-Analysis

ABSTRACT

Babiloni-Lopez, C, Fritz, N, Ramirez-Campillo, R, and Colado, JC. Water-based exercise in patients with nonspecific chronic low-back pain: a systematic review with meta-analysis. J Strength Cond Res 38(1): 206-219, 2024-This study aimed to systematically review and synthesize evidence (i.e., active [land-based training] and nonactive controls [e.g., receiving usual care]) regarding the effects of water-based training on patients with nonspecific chronic low-back pain (NSCLBP). Web of Science (WOS), PubMed (MEDLINE), EMBASE, EBSCO (SPORTDiscus; CINAHL), and PEDro were searched, with no date restrictions, until October 2021. The included studies satisfied the following criteria: (a) NSCLBP (≥12 weeks) patients, (b) water-based intervention, (c) control group (land-based trained; nonactive group), and (d) outcomes related to pain, disability, quality of life, or flexibility. The main outcome analyzed in the meta-analysis was pain intensity. Secondary outcomes included disability, body mass index, and flexibility. The random-effects model was used, and effect size (ES) values are presented with 95% confidence intervals (CIs). The impact of heterogeneity was assessed (I2 statistic), with values of <25%, 25-75%, and >75% representing low, moderate, and high levels, respectively. Alpha was set at p < 0.05. In conclusion, 15 studies (n = 524) were meta-analyzed. After intervention, pain intensity was reduced compared with nonactive controls (ES = -3.61; p < 0.001) and a similar reduction was noted when compared with land-based trained group (ES = -0.14; p = 0.359). Greater decrease in disability (ES = 2.15; p < 0.001) and greater increase in sit-and-reach (i.e., flexibility; ES = -2.44; p < 0.001) were noted after intervention compared with the nonactive group. In conclusion, water-based exercise therapy reduces pain intensity, disability, and increases flexibility in NSCLBP compared with nonactive subjects and was equally effective compared with land-based exercise to reduce pain. Favorable effects may be expected at ≤8 weeks. However, due to several methodological issues (e.g., high heterogeneity), for the improvement of most outcomes, we are unable to provide other than a weak recommendation in favor of intervention compared with control treatment.

Multicomponent and power training with elastic bands improve metabolic and inflammatory parameters, body composition and anthropometry, and physical function in older women with metabolic syndrome: A 20-week randomized, controlled trial

PURPOSE

This study aimed to explore the effects of 20 weeks of multicomponent or power training with elastic bands (EBs) on metabolic and inflammatory blood parameters, body composition, anthropometry, and physical function in older women with metabolic syndrome (MS).

METHODS

Ninety participants were randomly assigned to a multicomponent (MCG; n = 30), power (PG; n = 30), or a control group (CG; n = 30). The MCG performed balance, slow-speed strength, and aerobic training, twice per week. The PG completed a high-speed resistance training program twice per week, composed of three to four sets of ten repetitions of six overall body exercises at a perceived rating of effort for the first repetition of 3-4 on the OMNI-Resistance Exercise Scale EB. MS-related variables (glucose, triglycerides, and waist circumference) and cardiometabolic risk factors (high-density lipoprotein [HDL], glycosylated hemoglobin, total cholesterol, low-density lipoprotein cholesterol [LDL], C-reactive protein, and anthropometric profile) were assessed. Physical function was evaluated through balance, strength, and mobility tests.

RESULTS

An analysis of variance revealed that both training groups similarly improved most glycemic and lipidic profile parameters (p ≤ 0.006; d ≥ 0.46), body composition and anthropometry (p < 0.001; d ≥ 0.41), and physical function (p ≤ 0.005; d ≥ 0.69). Opposed to the PG, the MCG improved balance (p < 0.001; d = 0.96) and decreased the inflammatory status by downregulating C-reactive protein (p = 0.003; d = 0.47). On the other hand, the PG exhibited improvements in handgrip strength (p = 0.006; d = 0.48), while the MCG did not.

CONCLUSION

Therefore, multicomponent and power training with EBs are plausible strategies for improving the cardiometabolic health status and physical function in older women with MS.

High-Intensity Forward-Backward Plyometrics After the Warm-Up Entail Better Sprint and Change-of-Direction Performance Than Low-Intensity Side-to-Side Plyometrics

This study aimed to determine the acute effects of high-intensity forward-backward and low-intensity side-to-side plyometric jumps performed following the warm-up on sprint (5, 10, and 15 m) and change-of-direction (COD) (T-half test and repeated T-half tests) performance in youth volleyball players. After a familiarization week, 30 male volleyball players (age = 12.04 ± 1.03 years) performed three randomized conditions (no-plyometrics, high-intensity plyometrics, and low-intensity plyometrics) in three sessions. In a within-subject design, three sets of six repetitions of forward-backward 30-cm hurdle jumps (high-intensity) and side-to-side 20-cm hurdle jumps (low-intensity) were completed. Sprint and COD were tested after each of the conditions with a 2-min rest. A significant effect of the plyometric condition was observed on sprint (p < .001, ηp2 range: .56-.70) and COD (p < .01, ηp2=.24), but not on repeated COD. More specifically, the high-intensity plyometric condition exhibited significantly better results compared with the low-intensity plyometric (Cohen's d range: 0.73-1.21) and control conditions (Cohen's d range: 0.91-2.21). Due to the importance of speed and COD in volleyball, these results suggest that young volleyball players may benefit from high-intensity forward-backward plyometric protocols following the warm-up to improve subsequent performance.

Effects of different phenylcapsaicin doses on resistance training performance, muscle damage, protein breakdown, metabolic response, ratings of perceived exertion, and recovery: a randomized, triple-blinded, placebo-controlled, crossover trial

BACKGROUND

The aim of this study was to explore the effects of a low dose (LD) of 0.625 mg and a high dose (HD) of 2.5 mg of phenylcapsaicin (PC) on full squat (SQ) performance, active muscle (RPE-AM) and overall body (RPE-OB) ratings of perceived exertion, muscle damage, protein breakdown, metabolic response, and 24-h recovery in comparison to placebo (PLA).

METHOD

Twenty-five resistance-trained males (age = 21.00 ± 2.15 years, SQ 1-repetition maximum [1RM] normalized = 1.66 ± 0.22 kg) were enrolled in this randomized, triple-blinded, placebo-controlled, crossover trial. Participants completed 2 weekly sessions per condition (LD, HD, and PLA). The first session consisted of pre-blood testing of lactate, urea, and aspartate aminotransferases (AST) and 2 SQ repetitions with 60% 1RM followed by the resistance exercise protocol, which consisted of SQ sets of 3 × 8 × 70% 1RM monitoring lifting velocity. RPE-OB and RPE-AM were assessed after each set. After the first session, 2 SQ repetitions with 60% 1RM were performed, and blood lactate and urea posttests were collected. After 24 h, AST posttest and 1 × 2 × 60% 1RM were determined as biochemical and mechanical fatigue outcomes.

RESULTS

HD reported significant differences for RPE-AM, AST, and SQ performance compared to LD and PLA. Post-hoc analyses revealed that HD attained faster velocities in SQ than LD (p = 0.008). HD induced a lower RPE-AM when compared with LD (p = 0.02) and PLA (p = 0.004). PLA resulted in higher AST concentrations at 24-h post than HD (p = 0.02). No significant differences were observed for the rest of the comparisons.

CONCLUSIONS

This study suggests that PC may favorably influence SQ performance, RPE-AM, and muscle damage compared to PLA. However, HD exhibited most of the biochemical and mechanical anti-fatigue effects instead of LD.

Acute Intraocular Pressure Responses to Resistance Training in Combination With Blood Flow Restriction

Objective: To determine the effect of blood flow restriction (BFR) applied to the legs at different pressures (40% and 60%) on intraocular pressure (IOP) during the execution of ten repetitions maximum (10RM) in the half-squat exercise. Methods: Quasi-experimental, prospective study with 17 healthy physically active subjects (9 males and 8 females; 24.1 ± 4.2 years). Two sessions were conducted. The 10RM load was determined in the first session. The second session consisted of 10RM under three BFR conditions (no-BFR, 40%-BFR, and 60%-BFR) that were applied in random order. IOP was measured before each condition, immediately after each repetition, and after 1 minute of passive recovery. A two-way repeated-measures ANOVA (restriction type [no-BFR, 40%-BFR, and 60%-BFR] x measurement point [basal, repetitions 1-10, and recovery]) was applied on the IOP measurements. Results: A significant main effect of the BFR condition (p = .022, ƞp2 = 0.21) was observed due to the significantly higher mean IOP values for the 60%-BFR (19.0 ± 0.7 mmHg) compared to the no-BFR (18.0 ± 0.8 mmHg; p = .048, dunb = 1.30). Non-significant differences with a large effect size were reached between 60%-BFR and 40%-BFR (18.1 ± 0.8 mmHg; p = .081, dunb = 1.16) and between no-BFR and 40%-BFR (p = .686, dunb = 0.18). IOP increased approximately 3-4 mmHg from baseline to the last repetition. Conclusions: Low-pressure BFR (40%-BFR) in combination with moderate-load (10RM load) resistance exercise could be an effective and safe strength training strategy while avoiding IOP peaks associated with heavy-load resistance exercises. These findings incorporate novel insights into the most effective exercise strategies in individuals who need to maintain stable IOP levels (e.g., glaucoma patients).

Rating of Perceived Exertion in the First Repetition is Related to the Total Repetitions Performed in Elastic Bands Training

Several devices (e.g., linear transducers) have been used for predicting resistance training intensity. However, subjective scales, such as rating of perceived exertion (RPE), are proposed as reliable and easier-to-use tools for monitoring intensity during resistance training. Accordingly, different perceptive scales have been presented in previous research for monitoring intensity during resistance training with elastic bands. The aim was to assess the accuracy and reliability of RPE for quantifying the potential maximal repetitions that could be performed at a given RPE (from 2 to 8 of 10) obtained in the first repetition. For this purpose, 13 recreationally active participants (age: 26.33 [6.52] years, body mass index: 24.97 [5.08] kg/m2) were involved in two familiarization and two experimental sessions. In each session, participants randomly performed one set at each intensity of the first repetition from 2/10 to 8/10 until volitional failure in three different exercises (fly, military press, and push-press). An individual grip width of the elastic band was chosen in each set. The number of repetitions and heart rate were assessed. Significance level was set at p < .05. Repetitions decreased when intensity increased (p < .01) and heart rate was higher in the global exercise (i.e., push-press; p < .05), but nonsignificant differences between intensities were reported. The level of experience influenced the number of repetitions performed (p < .05). Intersession reliability was set from good to excellent (range: 0.64-0.91). Therefore, the RPE of the first repetition is a relevant and reliable parameter related to the total number of repetitions performed for each RPE value in trained participants enrolled in elastic bands resistance training.

Effects of different phenylcapsaicin doses on neuromuscular activity and mechanical performance in trained male subjects: a randomized, triple-blinded, crossover, placebo-controlled trial

Objective: This study aimed to examine the effects of phenylcapsaicin (PC) supplementation on strength performance and neuromuscular activity in young trained male subjects. Materials and methods: A total of 25 trained subjects [full-squat (SQ) one repetition maximum (1RM) = 125.6 ± 21.0 kg] were enrolled in this randomized, triple-blinded, crossover, placebo-controlled trial. The subjects performed a first session and a post-24 h session for each condition. In the first session, the subjects ingested a high dose of PC (HD, 2.5 mg), a low dose (LD, 0.625 mg), or a placebo (PLA). Their performance in SQ was assessed under a 3% × 8 × 70% 1RM protocol in the first session. Their performances in countermovement jump (CMJ), SQ with 60% 1RM, and isometric squat were measured before and after the SQ protocol in both sessions. The neural activity of the vastus lateralis (VL) and vastus medialis (VM) was recorded via surface electromyography (EMG) and averaged in both sessions. Results: Significant differences between the conditions were reported for lifting velocity, velocity loss, and the 60% load in dynamic SQ (p range = 0.02-0.04). Electrical changes were not identified for any outcome, although neural activity changed across time (p range ≤0.001-0.006). A significant condition × time effect was observed in CMJ compared to PLA (p ≤0.001) and LD (p ≤0.001). Intra-set analyses revealed higher velocities in HD compared to those in LD (p = 0.01) and PLA (p range = 0.004-0.008). Conclusion: Therefore, PC may improve the strength performance and attenuate the mechanical fatigue induced by resistance training in SQ and CMJ exercises.

Effects of phenylcapsaicin on aerobic capacity and physiological parameters in active young males: a randomized, triple-blinded, placebo-controlled, crossover trial

Objective: Phenylcapsaicin (PC) is a new capsaicin analog which has exhibited a higher bioavailability. This sudy assessed the effects of a low dose (LD) of 0.625 mg and a high dose (HD) of 2.5 mg of PC on aerobic capacity, substrate oxidation, energy metabolism and exercise physiological variables in young males. Materials and methods: Seventeen active males (age = 24.7 ± 6.0 years) enrolled to this randomized, triple-blinded, placebo-controlled, crossover trial. Participants attended the laboratory on 4 sessions separated by 72-96 h. A submaximal exercise test [to determine maximal fat oxidation (MFO) and the intensity at MFO (FATmax)] followed by a maximal incremental test (to determine VO2_max) were performed in a preliminary session. The subsequent sessions only differed in the supplement ingested [LD, HD or placebo (PLA)] and consisted of a steady-state test (60 min at FATmax) followed by a maximal incremental test. Energy metabolism, substrate oxidation, heart rate, general (gRPE) and quadriceps (RPEquad) rate of perceived exertion, skin temperature and thermal perception were tested. Results: Clavicle thermal perception was lower in HD compared to PLA and LD (p = 0.04) across time. HD reduced maximum heart rate in comparison to PLA and LD (p = 0.03). LD reported higher general RPE (RPEg) values during the steady-state test compared to PLA and HD across time (p = 0.02). HD and LD elicited higher peak of fat oxidation during the steady-state test compared with PLA (p = 0.05). Intra-test analyses revealed significant differences for fat oxidation (FATox) in favor of HD and LD compared to PLA (p = 0.002 and 0.002, respectively), and for carbohydrate oxidation (CHOox) (p = 0.05) and respiratory exchange ratio (RER) (p = 0.03) for PLA. In the incremental test, only general RPE at 60% of the maximal intensity (W) differed favoring HD (p ≤ 0.05). Conclusion: Therefore, PC may contribute to increase aerobic capacity through the improvement of fat oxidation, maximum heart rate and perceptual responses during exercise.

Exploring of two different equated instability resistance training programs on measure of physical fitness and lower limb asymmetry in pre-pubertal weightlifters

BACKGROUND

Although previous research in pediatric populations has reported performance enhancements following instability resistance training, the effects of different volumes on measures of balance, strength and power and lower limb asymmetry remain unclear.

OBJECTIVE

To compare the effect of two 8-week instability resistance training programs (IRT1: 2 sets x 8 repetitions, 20% one-repetition maximum (1RM); IRT2: 2 sets x 4 repetitions, 40% 1RM) in balance (center of pressure displacements), 1RM, single-leg jumps, and inter-limb asymmetry of prepubescent weightlifters.

METHODS

Thirty-two male athletes (10.94 ± 0.47 yrs, 17.05 ± 0.14 kg/m², and 6.44 ± 0.93% bodyfat) voluntarily participated and combined IRT (front and back squat, lunge, and deadlift) with their usual weightlifting training. Nonparametric tests evaluated the differences between pre- and post-intervention.

RESULTS

Significant improvements were encountered in all the variables for both groups (effect sizes [ES] from 0.46 to 2.60), except the inter-limb asymmetry and the velocity of displacement of the center of pressure, which did not improve in IRT2. It is also worth highlighting that in the single-leg jumps and center of pressure displacements, whereas no significant differences were observed between IRT1 and IRT2 in the baseline, significant differences appeared in the follow-up measurements.

CONCLUSION

IRT combined with weight-lifting training improves prepubescent weightlifters' performance; therefore, strength and conditioning coaches may consider including unstable devices with low loads into an overall conditioning program and warm-ups for prepuberal male weightlifters to promote their physical fitness and potentially decrease inter-limb asymmetry.

TRIAL REGISTRATION

This study does not report results related to healthcare interventions using human participants; therefore, it was not prospectively registered.

Effects of Microfiltered Seawater Intake and Variable Resistance Training on Strength, Bone Health, Body Composition, and Quality of Life in Older Women: A 32-Week Randomized, Double-Blinded, Placebo-Controlled Trial

The aim was to explore the effects of a 32-week resistance training (RT) intervention with elastic bands with or without microfiltered seawater (SW) supplementation on isokinetic strength, bone mineral density (BMD), body composition, and subjective quality of life in postmenopausal women. Ninety-three untrained women (age: 70.00 ± 6.26 years; body mass index: 22.05 ± 3.20 kg/m²; body fat: 37.77 ± 6.38%; 6.66 ± 1.01 s up-and-go test) voluntarily participated in this randomized, double-blinded, controlled trial. Participants were allocated into four groups (RT+SW, RT+PLA, CON+SW, and CON+PLA). The RT intervention (twice weekly) consisted of different exercises for the whole body performed at submaximal intensities with elastic bands. Both control groups were not involved in any exercise program. A two-way mixed analysis of variance of repeated measures revealed significant improvements in almost all the variables in both intervention groups (p < 0.05). However, significant differences with controls were encountered in isokinetic strength, body fat percentage, and bodily pain. Although the group with SW supplementation obtained greater effect sizes, non-significant differences between both RT groups were observed. In conclusion, the determinant factor of the adaptations seems to be RT rather than SW.

Effects of Game Weekly Frequency on Subjective Training Load, Wellness, and Injury Rate in Male Elite Soccer Players

To compare the effects of playing one or two games per week on subjective perceived exertion (RPE) and (RPE-based) training load, monotony index, sleep, stress, fatigue, and muscle soreness (Hooper index), total mood disturbance, and injury rate in elite soccer players. Fourteen males from a first-division soccer club (age: 24.42 ± 4.80 years) competed in two games per week for six weeks and one game per week for twelve weeks (a total of 24 games). Paired t-tests and non-parametric Wilcoxon signed ranks evaluated the significance of the differences (p < 0.05). The main findings were that RPE was significantly larger when playing two games per week compared with one game. However, subject total and mean training load, mood disturbance, monotony, and subjective perception of sleep, stress, fatigue, muscle soreness monitoring (Hooper index), and the number of injuries were not different. The findings suggested that competing in two matches per week does not negatively influence injury rate and players’ perceptions of training load or wellness, even though players perceive two games per week as more physically demanding compared with one game per week.

The Use of Elastic Bands in Velocity-Based Training Allows Greater Acute External Training Stimulus and Lower Perceived Effort Compared to Weight Plates

The objective was to compare the mean propulsive velocity (MPV), maximum power (PMAX), heart rate, and rate of perceived exertion (RPE) during the parallel squat using elastic bands (EB) or weight plates (WP) to load the bar. The effect of relative strength on the dependent variables was analysed. Additionally, the potential of the RPE to predict external load parameters was assessed. Eighteen trained volunteers squatted at 40%, 55%, 70%, and 85% of their one-repetition maximum with EB and WP (a total of eight sets) in random order. Dependent variables were measured at the first and last repetition (i.e., 10% velocity loss). Two identical sessions were conducted to assess the reliability of measurements. Compared to WP, EB allowed a significantly greater number of repetitions, MPV, and PMAX, and significantly lower RPE. The RPE of the first repetition was a significant predictor of the external load of the set. The RPE showed good repeatability and was not influenced by the relative strength of athletes. In conclusion, compared to WP, the use of EB allows for greater external load with reduced internal load responses in a wide spectrum of load-based intensities. The potential implications of these novel findings are discussed in the manuscript.

Effects of Plyometric Jump Training on Measures of Physical Fitness and Sport-Specific Performance of Water Sports Athletes: A Systematic Review with Meta-analysis

Background

A growing body of literature is available regarding the effects of plyometric jump training (PJT) on measures of physical fitness (PF) and sport-specific performance (SSP) in-water sports athletes (WSA, i.e. those competing in sports that are practiced on [e.g. rowing] or in [e.g. swimming; water polo] water). Indeed, incoherent findings have been observed across individual studies making it difficult to provide the scientific community and coaches with consistent evidence. As such, a comprehensive systematic literature search should be conducted to clarify the existent evidence, identify the major gaps in the literature, and offer recommendations for future studies.

Aim

To examine the effects of PJT compared with active/specific-active controls on the PF (one-repetition maximum back squat strength, squat jump height, countermovement jump height, horizontal jump distance, body mass, fat mass, thigh girth) and SSP (in-water vertical jump, in-water agility, time trial) outcomes in WSA, through a systematic review with meta-analysis of randomized and non-randomized controlled studies.

Methods

The electronic databases PubMed, Scopus, and Web of Science were searched up to January 2022. According to the PICOS approach, the eligibility criteria were: (population) healthy WSA; (intervention) PJT interventions involving unilateral and/or bilateral jumps, and a minimal duration of ≥ 3 weeks; (comparator) active (i.e. standard sports training) or specific-active (i.e. alternative training intervention) control group(s); (outcome) at least one measure of PF (e.g. jump height) and/or SSP (e.g. time trial) before and after training; and (study design) multi-groups randomized and non-randomized controlled trials. The Physiotherapy Evidence Database (PEDro) scale was used to assess the methodological quality of the included studies. The DerSimonian and Laird random-effects model was used to compute the meta-analyses, reporting effect sizes (ES, i.e. Hedges’ g) with 95% confidence intervals (95% CIs). Statistical significance was set at p ≤ 0.05. Certainty or confidence in the body of evidence for each outcome was assessed using Grading of Recommendations Assessment, Development, and Evaluation (GRADE), considering its five dimensions: risk of bias in studies, indirectness, inconsistency, imprecision, and risk of publication bias.

Results

A total of 11,028 studies were identified with 26 considered eligible for inclusion. The median PEDro score across the included studies was 5.5 (moderate-to-high methodological quality). The included studies involved a total of 618 WSA of both sexes (330 participants in the intervention groups [31 groups] and 288 participants in the control groups [26 groups]), aged between 10 and 26 years, and from different sports disciplines such as swimming, triathlon, rowing, artistic swimming, and water polo. The duration of the training programmes in the intervention and control groups ranged from 4 to 36 weeks. The results of the meta-analysis indicated no effects of PJT compared to control conditions (including specific-active controls) for in-water vertical jump or agility (ES =  − 0.15 to 0.03; p = 0.477 to 0.899), or for body mass, fat mass, and thigh girth (ES = 0.06 to 0.15; p = 0.452 to 0.841). In terms of measures of PF, moderate-to-large effects were noted in favour of the PJT groups compared to the control groups (including specific-active control groups) for one-repetition maximum back squat strength, horizontal jump distance, squat jump height, and countermovement jump height (ES = 0.67 to 1.47; p = 0.041 to < 0.001), in addition to a small effect noted in favour of the PJT for SSP time-trial speed (ES = 0.42; p = 0.005). Certainty of evidence across the included studies varied from very low-to-moderate.

Conclusions

PJT is more effective to improve measures of PF and SSP in WSA compared to control conditions involving traditional sport-specific training as well as alternative training interventions (e.g. resistance training). It is worth noting that the present findings are derived from 26 studies of moderate-to-high methodological quality, low-to-moderate impact of heterogeneity, and very low-to-moderate certainty of evidence based on GRADE.

Trial registration The protocol for this systematic review with meta-analysis was published in the Open Science platform (OSF) on January 23, 2022, under the registration doi https://doi.org/10.17605/OSF.IO/NWHS3 (internet archive link: https://archive.org/details/osf-registrations-nwhs3-v1).

Adding the Load Just Above Sticking Point Using Elastic Bands Optimizes Squat Performance, Perceived Effort Rate, and Cardiovascular Responses

Modifying basal elongation of elastic bands (EB) has been proven useful to increase some parameters of the intensity in variable resistance training. Therefore, the question arises as to whether the pertinent resistance could be applied with EB immediately above the sticking point in squat exercises to optimize the performance. The purpose was to analyze some variables of the external (kilograms and number of repetitions) and internal load (heart rate, blood pressure, and rate of perceived exertion) after six different conditions of the squat exercise when using weight plates (WP) or EB (placed at different points of the range of motion) and applying maximal or submaximal effort. Twenty physically active males (25.50 ± 5.26 yrs) underwent two sessions for familiarization and one for assessment. The six conditions (three with WP and three with EB) were randomly performed. The sticking point of each subject was measured using the knee joint angle and the resistance was applied with EB at this height. Immediately after finishing each set subjects reported perceived effort rate and cardiovascular measurements were taken. Repetitions completed, and kilograms used were recorded. Repeated measures testing evaluated differences between conditions. EB permitted performing 8 more repetitions compared to WP when the same load was added at standing position. Adding the load immediately above the sticking point significantly (p < 0.05) increased 24.7% the kilograms used and permitted participants to perform 3 more repetitions. Internal load measurements suggested that EB could significantly (p < 0.05) reduce the perceived effort rate and/or physiological stress depending on their application. EB are a suitable device to load the bar for squat exercises in fit young men. According to the necessities of the subjects, if the load with EB is added at different points of the range of motion, it could be possible to overcome the sticking point, to maximize the performance and/or modulate cardiovascular and perceptual responses.

Concurrent and Construct Validation of a New Scale for Rating Perceived Exertion during Elastic Resistance Training in The Elderly

The purpose of the study was to examine the concurrent and construct validity of a new perceptual scale to control the exercise intensity using elastic bands (Resistance Intensity Scale for Exercise; RISE) in the elderly. Twenty-six participants underwent two sessions consisting of 4 exercises. The participants performed three sets of 15 repetitions per exercise of either low, medium, or high intensity. The criterion variables were heart rate and applied force (mean and peak). Following the final repetition of each set, active muscle (AM) and overall body (OB) ratings of perceived exertion (RPE) were collected from RISE and the OMNI-Resistance Exercise Scale of perceived exertion with elastic bands (OMNI-RES EB). Construct validity was established by correlating the perceptual score obtained from both scales, RISE and OMNI-RES EB. Significant (p ≤ 0.05) and positive linear relationships between both scales were found (RPE-AM R² = 0.90; RPE-OB R² = 0.77). Significant differences in heart rate, applied force, and RISE scores were observed between the sets of the three intensities. For all 4 analyzed exercises, high-intensity sets elicited higher heart rate, applied force, and perceptual scores compared with the medium- and low-intensity sets. Furthermore, the medium-intensity sets produced higher perceptual, physiologic, and performance responses than the low-intensity sets. Intersession reliability was 0.88 for heart rate, 0.94 and 0.95 for applied force, 0.88 for the RPE-AM, and 0.80 for the RPE-OB. Conclusion: The RISE scale can be considered a valid method for assessing the perceived exertion during resistance exercises performed with elastic bands in the elderly.

Concurrent and Construct Validation of a Scale for Rating Perceived Exertion in Aquatic Cycling for Young Men

Aquatic cycling is a program of physical exercises performed with immersed stationary bikes. Few studies have provided evidence about the intensity control during its practice. Therefore, the primary aim of this study was to examine the concurrent and construct validity of a new scale for rating perceived exertion (RPE) during aquatic cycling in young men. Thirty physically active, healthy young men performed a load-incremented aquatic cycle ergometer protocol. Concurrent validity was established by correlating the Aquatic Cycling Scale (ACS) with oxygen uptake, pulmonary ventilation (VE), heart rate (HR), and blood lactate concentration (BL) responses to the maximal load-incremental test. Construct validity was established by correlating RPE derived from the Aquatic Cycling Scale (0-10) from the Borg Scale (6-20). RPE-overall, maximal oxygen uptake (VO2max), oxygen uptake indexed to body weight (VO2), VE, HR, and BL were measured during each exercise stage. The range of exercise responses across the incremental test were VO2max = 1.07-3.55 L/min, VO2 = 14.26-46.89 ml/Kg/min, VE = 23.17-138.57 L/min, HR = 99.54-173.31 beats/min, BL= 1.18-11.63 mM, ACS RPE-overall = 1.11-9.33. Correlation/regression analyses showed ACS RPE as a positive linear function of VO2max (r = 0.78; p < 0.05), VO2 (r = 0.87; p < 0.05), VE (r = 0.86; p < 0.05), HR (r = 0.77; p < 0.05), and BL (r = 0.85; p < 0.05). RPE-ACS distributed as a positive linear function of the RPE-Borg Scale (r = 0.97; p < 0.05). ANOVA indicated that an incremental pedalling cadence of 15 revolutions per minute (rpm) provoked significant differences (p < 0.05) regarding previous stages in the majority of the variables analysed. The Aquatic Cycling Scale is an appropriate tool for monitoring exertion intensity during aquatic cycling in fit men. A brief increment in aquatic pedalling cadence of 15 rpm increases the intensity of the aquatic pedalling exercise.

Acute Effects of Aerobic Exercise and Active Videogames on Cognitive Flexibility, Reaction Time, and Perceived Exertion in Older Adults

Objective: The aim of this study was to analyze the acute effects of aerobic exercise (AE), active videogames (AVG), and AE+AVG on cognitive flexibility, choice reaction time (CRT), and postexercise rate of perceived exertion (RPE) in a sample composed of 49 older adults, 11 men and 38 women (age M = 67.7 ± 4.7 years). Materials and Methods: An incomplete intrasubject factorial design was followed. Participants were randomly divided into three experimental groups, and each one performed two of three different sessions (A, B, or C). In session A, participants rode on a cycle ergometer for 30 minutes (AE). In session B, they rode on a cycle ergometer for 30 minutes while playing an AVG (AE+AVG). In session C, they only played an AVG. Data were analyzed with a repeated-measures general linear model. Results: Intrasubject pre-post-analysis showed that the three sessions improved CRT, although motor reaction time did not improve significantly with AE. On the contrary, intrasubjects' postanalysis showed better results of AVG compared with AE (lower % of nonperseverative errors) and AE+AVG (less failures to maintain set, although the number of correct responses decreased). AE+AVG showed benefits in RPE compared with AE. Conclusions: The practice of AE and/or AVG acutely improves CRT in older adults, but only AVG improved some variables of cognitive flexibility. Moreover, postexercise RPE was higher after AE in comparison with other conditions (AVG, AE+AVG).

Effects of Different Chair-Based Exercises on Salivary Biomarkers and Functional Autonomy in Institutionalized Older Women

PURPOSE

The aim of this study was to test the effects of chair-based exercise programs on salivary stress hormones, physical fitness, and functional autonomy of institutionalized older women.

METHOD

In total, 47 participants (80 ± 8.04 years old) were recruited and allocated into three groups: chair-based aerobic exercises (CAE, n = 19), chair-based elastic-band strength exercises (CSE, n = 15), and a control group (CG, n = 13). A 14-week exercise intervention was done for the CAE and CSE groups, two times per week, in no consecutive days. Members of the CG did not participate in any type of exercise but kept their regular lifestyle. Fear of falling, autonomy, physical fitness, salivary cortisol, and alpha-amylase levels were assessed before and after the intervention.

RESULTS

The CAE group improved upper and lower body strength, agility-dynamic balance, and autonomy, with fear of falling decreasing significantly (p < .05, moderate effect size). Both exercise groups showed a trend toward an increase in salivary alpha-amylase levels (CAE = 43%, d = .31, and CSE = 44%, d = .41).

CONCLUSION

Both exercise programs were able to improve functional autonomy, even in elders older than 80 years of age. It might be interesting to investigate the effectiveness of combining both aerobic and strength exercises in a unique protocol. The modulation effect of exercise in the hormonal responses needs to be further explored.

Positive Effects of a Short-Term Intense Elastic Resistance Training Program on Body Composition and Physical Functioning in Overweight Older Women

The aim of this study was to investigate the effects of a resistance training program (RTP) in older overweight women (OOW) using two different types of elastic devices.

METHODS

This study was a randomized controlled trial with pre- and postintervention measures. Participants included OOW, aged 60-85 years, with no medical history of disease that would preclude them from engaging in physical exercise. Participants were randomly divided into the following groups: elastic tubes with handles group (ETG; n = 22), traditional elastic bands group ( n = 21), and control group (CG; n = 20). Exercise groups (EGs) performed the following supervised RTP: 8 weeks, twice weekly, six overall body exercises, and 3-4 sets of 10 repetitions at a rate of perceived exertion (RPE) of 7-9 on the OMNI-Resistance Exercise Scale of perceived exertion. The controls did not change their usual lifestyle. Outcome measures included body composition (BC; total and regional percentage of fat mass [FM] and fat-free mass [FFM]) and physical performance (PP; dynamic and isometric strength, flexibility, agility/dynamic balance, and endurance).

RESULTS

Both EGs exhibited significantly reduced FM in the upper limbs (ULs) and trunk and increased FFM in the UL, while the ETG exhibited a significantly increased trunk FFM. Both EGs improved in PP, and there were no intergroup differences. Trunk FM and FFM and meters walked differed significantly between the ETG and CG. The CG did not exhibit any significant changes.

CONCLUSION

Training with elastic devices at a moderate-high RPE produces short-term improvements in BC and PP in OOW.

The Effect of Moderate- Versus High-Intensity Resistance Training on Systemic Redox State and DNA Damage in Healthy Older Women

This study investigated effects of a 16-week progressive resistance training program (RTP) with elastic bands at two different intensities on systemic redox state, DNA damage, and physical function in healthy older women.

Methods:

Participants were randomly assigned to the high-intensity group (HIGH; n = 39), moderate-intensity group (MOD; n = 31), or control group (CG; n = 23). The exercise groups performed an RTP twice a week with three to four sets of 6 (HIGH) or 15 (MOD) repetitions of six overall body exercises at a perceived exertion rate of 8–9 on the OMNI-Resistance Exercise Scale for use with elastic bands. Thiol redox state was determined by reduced glutathione (GSH), oxidized glutathione (GSSG), and GSSG/GSH in blood mononuclear cells. Degree of DNA damage was assessed by presence of the oxidized DNA base molecule 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-OHdG) in urine. Physical function monitoring was based on the arm curl, chair stand, up and go, and 6-min walk tests.

Results:

The HIGH group showed a significant increase in 8-OHdG (+71.07%, effect size [ES] = 1.12) and a significant decrease in GSH (−10.91, ES = −0.69), while the MOD group showed a significant decrease in 8-OHdG levels (−25.66%, ES = −0.69) with no changes in thiol redox state. GSH levels differed significantly between the HIGH and CG groups posttest. The exercise groups showed significant improvements in physical function with no differences between groups.

Conclusion:

RTP at a moderate rather than high intensity may be a better strategy to reduce DNA damage in healthy older women while also increasing independence.

Concurrent validation of the OMNI-Resistance Exercise Scale of perceived exertion with elastic bands in the elderly

PURPOSE

To examine the concurrent validity of the OMNI-Resistance Exercise Scale of perceived exertion using elastic bands in elder population.

METHODS

Twenty-six participants performed three separate sets of 15 repetitions (low- medium- and high-intensity) for 4 different exercises (2 for the upper-limb and 2 for the lower limb), over two different testing sessions. The criterion variables were heart rate and applied force (average and maximum). In addition to these dependent variables, the active muscle and overall body OMNI-RES for elastic bands scores were collected at the end of each repetition.

RESULTS

Significant differences in heart rate, applied force and OMNI-RES scores between the low- and high-intensity sets were observed. For all the four exercises, high intensity sets elicited higher heart rate, applied force, and RPE compared to the medium and the low overloads. Intraclass correlation coefficient was 0.79 in heart rate and ranged 0.69-0.80 in OMNI-RES Scale and 0.76-0.86 for the applied force.

CONCLUSION

A strong positive and linear relationship was observed between the rating of perceived exertion and both heart rate and applied force. The OMNI-RES scale with elastic bands demonstrated to be a valid method for assessing the perceived exertion during resistance exercises and consequently represent a useful tool for prescribing exercise intensity to the elderly.

Combined resistance and endurance training at a moderate-to-high intensity improves physical condition and quality of life in liver transplant patients

Although currently moderate and high intensity concurrent physical exercise is prescribed in populations with special needs due to its greater effect on physical condition and health-related quality of life (HRQOL), there are no data in the liver transplantation (LT) setting. The aim of this study is to evaluate changes in maximal strength, aerobic capacity, body composition, liver function, and HRQOL in LT patients after a moderate-to-high intensity combined resistance-endurance training. Six months after LT, 54 patients were randomized into 2 groups: intervention group (IG) and control group (CG). A total of 50 patients completed the study with repeat testing at 6 and 12 months after LT. The IG completed a 6-month exercise training program, consisting of exercising 2 days for 24 weeks in the hospital facilities, whereas the CG followed usual care recommendations. Patients completed a 5-multijoint exercise circuit with elastic bands involving the major muscle groups. The effects of the concurrent training program on maximal oxygen consumption, overall and regional maximal strength, body composition, liver function, and HRQOL were analyzed. The IG showed a significant improvement (P < 0.05) in outcome measurements compared with the CG in aerobic capacity, hip extension, elbow flexion, overall maximal strength, physical functioning, and vitality of HRQOL, whereas no changes were observed in body composition and liver function tests. In conclusion, this is the first study that combines supervised resistance and aerobic training performed at moderate-to-high intensity in LT recipients. It results in significant improvements in aerobic capacity, maximal strength, and HRQOL. Liver Transplantation 23 1273-1281 2017 AASLD.

Strength Training Decreases Inflammation and Increases Cognition and Physical Fitness in Older Women with Cognitive Impairment

Introduction: Cognitive impairment that affects older adults is commonly associated with an inflammatory imbalance, resulting in decreased physical fitness. Exercise has been pointed to mitigate immunosenescence and cognitive impairment associated with aging, while increase in physical fitness. However, few studies explored the relationship between changes in cytokine concentration and improvement on cognition due to elastic band strength training. The aim of this study was to investigate the effects of strength training on pro-and anti-inflammatory cytokines, hematological markers and physical fitness of older women with cognitive impairment.

Methods: Thirty-three women (82.7 ± 5.7 years old) participated in the study and were divided in two groups: strength exercise training group (ST; n = 16) and Control Group (CG; n = 17) and were evaluated before and after 28 weeks of the exercise program. The CG did not undergo any type of exercise programs. Data for IL-10, TNF-α, IFN-γ, C-Reactive Protein (CRP), white blood counts (WBC), red blood counts (RBC), Mini Mental State Examination (MMSE) and physical fitness tests were analyzed in both moments.

Results: IL-10 increased in the ST group without changes in CG. TNF-α and CRP increased in the control group while no changes were observed for IFN-γ in both groups. Strength training decreased leukocyte and lymphocyte counts and increase hemoglobin, mean cell volume and mean cell hemoglobin concentration. The MMSE score increased in strength training group but remained unchanged in the control group. A correlation between the variation of granulocyte counts and the MMSE scores was also observed within the total sample. An improvement in physical fitness was observed with strength training.

Conclusion: Resistance exercise promoted better anti-inflammatory balance and physical performance simultaneously with an increase in cognitive profile in older women with cognitive impairment.

Trunk muscle activity during different variations of the supine plank exercise

BACKGROUND

Exercises providing neuromuscular challenges of the spinal muscles are desired for core stability, which is important for workers with heavy manual labour as well as people recovering from back pain.

PURPOSE

This study evaluated whether using a suspended modality increases trunk muscle activity during unilateral or bilateral isometric supine planks.

DESIGN

Cross-sectional.

METHODS

Twenty university students participated in this cross-sectional study. Each subject performed four different conditions: bilateral stable supine plank, unilateral stable supine plank, bilateral suspended supine plank and unilateral suspended supine plank. Surface electromyography (EMG) signals were recorded for the upper rectus abdominis (UP ABS), lower rectus abdominis (LOW ABS), external oblique (OBLIQ) and lumbar erector spinae (LUMB). Peak EMG of the filtered signals were normalized to the maximum voluntary isometric contraction (MVIC).

RESULTS

No differences between exercises were found for UP ABS, LOW ABS and OBLIQ muscle activity. The unilateral suspended supine plank provided the highest LUMB activity (20% of MVIC) whiles the bilateral stable supine plank provided the lowest activity (11% of MVIC).

CONCLUSIONS

The combination of unilateral variations with a suspended support provides the greatest LUMB muscle activity, while using these variations separately only provides advantages when compared with regular planks.

Metabolic and Functional Profile of Premenopausal Women With Metabolic Syndrome After Training With Elastics as Compared to Free Weights

The aim of this study was to compare the effects of a strength training program (STP) using free weights (FW) versus elastic tubing (ET) in 62 premenopausal, sedentary women diagnosed with metabolic syndrome (MS). Participants were randomly assigned to the FW or ET experimental group (EG) or a control group whose members remained sedentary. Members of each EG followed their assigned STP for 12 weeks, and biomarkers (BMs) related to MS and motor function (MF) parameters were evaluated. Both EGs showed a significant reduction in C-reactive protein level and a positive trend in the other BMs. Almost all MF parameters increased significantly in both EGs. No positive changes were found in the CG. These results indicate that the implementation of an STP, with either FW or ET, improves both metabolic health and MF and should be considered part of the basic approach to health care in women.

Bench press and push-up at comparable levels of muscle activity results in similar strength gains

Electromyography (EMG) exercise evaluation is commonly used to measure the intensity of muscle contraction. Although researchers assume that biomechanically comparable resistance exercises with similar high EMG levels will produce similar strength gains over the long term, no studies have actually corroborated this hypothesis. This study evaluated EMG levels during 6 repetition maximum (6RM) bench press and push-up, and subsequently performed a 5-week training period where subjects were randomly divided into 3 groups (i.e., 6RM bench press group, 6RM elastic band push-up group, or control group) to evaluate muscle strength gains. Thirty university students with advanced resistance training experience participated in the 2-part study. During the training period, exercises were performed using the same loads and variables that were used during the EMG data collection. At baseline, EMG amplitude showed no significant difference between 6RM bench press and band push-up. Significant differences among the groups were found for percent change (Δ) between pretest and posttest for 6RM (p = 0.017) and for 1 repetition maximum (1RM) (p < 0.001). Six repetition maximum bench press group and 6RM elastic band push-up group improved their 1RM and 6RM (Δ ranging from 13.65 to 22.21) tests significantly with similar gains, whereas control group remains unchanged. Thus, when the EMG values are comparable and the same conditions are reproduced, the aforementioned exercises can provide similar muscle strength gains.

CORE MUSCLE ACTIVITY DURING THE CLEAN AND JERK LIFT WITH BARBELL VERSUS SANDBAGS AND WATER BAGS

PURPOSE/BACKGROUND

While the traditional clean and jerk maneuver implies simultaneous participation of a large number of muscle groups, the use of this exercise with some variations to enhance core muscle activity remains uninvestigated. The purpose of this study was to compare the muscle activity during clean and jerk lift when performed with a barbell, sandbag and a water bag at same absolute load.

STUDY DESIGN

Descriptive, repeated-measures study.

METHODS

Twenty-one young fit male university students (age: 25 ± 2.66 years; height: 180.71 ± 5.42 cm; body mass: 80.32 ± 9.8 kg; body fat percentage: 12.41 ± 3.56 %) participated. Surface electromyographic (EMG) signals were recorded from the anterior deltoid (AD), external oblique (OBLIQ), lumbar erector spinae (LUMB), and gluteus medius (GM) and were expressed as a percentage of the maximum voluntary isometric contraction (MVIC).

RESULTS

There were no significantly significant differences for AD muscle activity between conditions, whereas muscle activation values for OBLIQ (60%MVIC), GM (29%MVIC) and LUMB (85%MVIC) were significantly higher during the water bag power clean and jerk maneuver when compared with the other conditions.

CONCLUSIONS

The clean and jerk is an exercise that may be used to enhance core muscle activity. Performing the maneuver with water bags resulted in higher core muscle activity compared with sandbag and standard barbell versions.

LEVEL OF EVIDENCE

3.

Core muscle activity in a series of balance exercises with different stability conditions

Literature that provides progression models based on core muscle activity and postural manipulations is scarce. The purpose of this study was to investigate the core muscle activity in a series of balance exercises with different stability levels and additional elastic resistance. A descriptive study of electromyography (EMG) was performed with forty-four healthy subjects that completed 12 exercises in a random order. Exercises were performed unipedally or bipedally with or without elastic tubing as resistance on various unstable (uncontrolled multiaxial and uniaxial movement) and stable surfaces. Surface EMG on the lumbar multífidus spinae (LM), thoracic multífidus spinae (TM), lumbar erector spinae (LE), thoracic erector spinae (TE) and gluteus maximus (GM), on the dominant side of the body were collected to quantify the amount of muscle activity and were expressed as a % of the maximum voluntary isometric contraction (MVIC). Significant differences (p<.001) were found between exercises. The three unipedal standing exercises with additional elastic resistance generated the greatest EMG values, ranging from 19% MVIC to 30% MVIC. Postural manipulations with additional elastic resistance and/or unstable devices increase core muscle activity. An adequate exercise progression based on global core EMG could start with seated positions, progressing to bipedal standing stance (i.e., from either multiaxial or stable surface to uniaxial surface). Following this, unipedal standing positions may be performed (i.e., from either multiaxial or stable surface to uniaxial surface) and finally, elastic resistance must be added in order to increase EMG levels (i.e., from stable surface progressing to any of the used unstable surfaces).