The role of volume-load in strength and absolute endurance adaptations in adolescent's performing high- or low-load resistance training

Current methods for the exercise dose equalization in resistance training drive to markedly different session-induced efforts

BACKGROUND

Effects comparison of resistance exercises may require equalizing the exercise-induced dose, this is currently done by using methods based on total weight lifted or on sets performed until failure. Dose equalization of resistance training sessions by these methods was analyzed in the present study.

METHODS

Twelve trained participants performed five bench-press sessions with a similar relative endpoint determined by the inability to complete a set of 50% of the maximum repetitions number (MNR). Sessions were performed at 50 or 85% of one-repetition maximum (1-RM) with sets until failure or sets prescribing 50% of MNR. The last session was performed with a reduced recovery pause to match the exercise density (total weight lifted/pause duration) of a previous session.

RESULTS

Sessions resulted in different total weight lifted (3158±1592 kg at 85% of 1-RM vs. 5330±1967 at 50%, P<0.001) and number of sets until failure (5.1±1.9 at 85% of 1-RM vs. 2.9±1.1 at 50%, P<0.001). Matching of sessions' density suppressed the differences in the number of sets performed (P=0.50).

CONCLUSIONS

Protocols' equalization based on the total weight lifted is likely to result in exercise volumes close to maximums when performed with heavy loads, whereas equalization based on sets to failure could induce a sets number close to the maximum when performed with light loads. Current methods for protocols equalization rely on gross values of exercise volume without considering maximums, that can result in markedly unbalanced efforts and biased results. Prescribing each exercise volume according to its maximum might optimize the training protocols' equalization.

Implementation and Evaluation of a 10-Week Kettlebell Training Load Distribution on Strength and Aerobic Capacity in Recreationally Trained Women

Objective

: The purpose of this study was to characterize the dynamic distribution of training loads in a kettlebell program and evaluate its effects on muscle strength and aerobic capacity.

Methods

Fourteen recreationally active women with no kettlebell training experience (age: 25.86 ± 5.35 years; V̇O2max = 35.14 ± 5.58 mL/kg/min; body mass = 62.13 ± 13.40 kg; height = 164.75 ± 5.77 cm; body mass index = 22.68 ± 3.99 kg/m²) completed a 10-week kettlebell training program. The kettlebell training program was divided into three phases: Phase I (2 weeks), phase II (4 weeks), and Phase III (4 weeks). Maximum muscle strength (1RM) and aerobic fitness (V̇O2max) measurements were performed before (Pre) and after (Post) training. The external and internal loads were represented by the session's total volume and perceived exertion method.

Results

An increase in maximum strength (P < .001; ∆% = 23.73; effect size = 0.87) and V̇O2max (P = .004; ∆% = 9.63; effect size = 0.57) was observed when comparing Pre and Post measurements. There was an increase in total volume when phases I and II (P < .001), phases I and III (P < .001), and phases II and III (P < .001) of the training were compared. The internal load values increased significantly between phases I and II (P < .001). However, there was no difference when comparing phases II and III (P = .796).

Conclusion

The total volume increases during the training phases, and the training load was similar in phases II and III. Furthermore, were observed higher V̇O2max and strength (1 RM load) values.

Cardiac autonomic responses to high-intensity kettlebell training in untrained young women: A pilot study

BACKGROUND

and purpose: The autonomic recovery after exercise provides information about the cardiovascular overload employed during the training session. The autonomic response over a training course is unclear in exercises performed at high intensities, such as kettlebell training. The study aimed to characterize the cardiac autonomic modulation after exercise in three distinct phases of a high-intensity kettlebell training program in young women.

METHODS

Ten women (25.0 ± 2.9 years; 23.4 ± 3.0 kg/m2) were submitted to 10 weeks of training divided into three phases (three times a week). The autonomic response was measured in the pre-exercise and at 10, 20, and 30 min of recovery and evaluated temporal and linear analysis of heart rate variability (HRV) indices.

RESULTS

vigorous intensity was performed in the sessions (75-86% HRmax). There was a significant reduction of HRV measured during post-exercise recovery (p < 0.05). In the initial two phases, the parasympathetic activity did not rebound to pre-exercise values (p < 0.05), and sympathetic was increased significantly until the end of the recovery period (p < 0.05). The third phase demonstrated the resumption of almost all the HRV indices at pre-exercise values at 20 min of recovery (p > 0.05).

CONCLUSION

The high-intensity kettlebell training program reduces HRV to 30 min of recovery (phases I and II). In the last phase (III), HRV components returned in 20 min. In addition, the program promoted improvement in aerobic fitness.

Effect of 10 sets versus 5 sets of resistance training on muscular endurance

BACKGROUND

A paucity of research exists examining whether resistance training with a greater number of sets per exercise enhances the development of muscular endurance. The aim of this study was to investigate the effects of ten sets versus five sets of resistance training on muscle endurance.

METHODS

Fifteen healthy males (age 23.7 ± 4.6 y) with at least 1 year resistance training experience were randomly assigned to 6 weeks of 10 sets (10-SET) or 5 sets (5-SET) of 10 repetitions at 60-80% one-repetition maximum (1RM) for specific compound resistance exercises with rest intervals between sets of 60-90 s and 60 s between exercises, performed 3 times per week. Relative muscle endurance test was assessed via maximal repetitions using 70% 1RM for the bench press, lat pulldown and leg press.

RESULTS

There was a significant increase in the number of repetitions to failure in the muscle endurance test for the leg press in 10-SET (40.9%, p = 0.04) and 5-SET (27.9%; p = 0.03), although no statistical differences between groups in the post-intervention results. Both groups increased volume-load in the muscle endurance test for the bench press (≥14.3%, p<0.05) and leg press (≥36.7%, p<0.05), but there were no statistical differences between groups in the post-intervention results.

CONCLUSIONS

Findings suggest that performing 10 sets compared to 5 sets of resistance training does not enhance the development of relative muscle endurance. The volume-load accrued within an individual set rather than across sets may be of greater importance when targeting muscular endurance.

Influence of Resistance Training Exercise Order on Muscle Strength, Hypertrophy, and Anabolic Hormones in Older Women: A Randomized Controlled Trial

Tomeleri, CM, Ribeiro, AS, Nunes, JP, Schoenfeld, BJ, Souza, MF, Schiavoni, D, Junior, PS, Cavaglieri, CR, Cunha, PM, Venturini, D, Barbosa, DS, and Cyrino, ES. Influence of resistance training exercise order on muscle strength, hypertrophy, and anabolic hormones in older women: a randomized controlled trial. J Strength Cond Res 34(11): 3103-3109, 2020-The purpose of this study was to analyze the effects of resistance training (RT) exercise order on muscle strength, hypertrophy, and anabolic hormones in older women. Forty-four older women were randomly assigned to 1 of 3 groups: a nonexercise control group (CON, n = 15) and two RT groups that performed a 12-week RT program in a multijoint to single-joint order (MJ-SJ, n = 14), or in a single-joint to multijoint order (SJ-MJ, n = 15). The RT protocol (3×/week) encompassed 8 exercises, with 3 sets of 10-15 repetitions performed per exercise. One repetition maximum tests were used to evaluate muscle strength; dual-energy X-ray absorptiometry was used to estimate lean soft tissue. Both training groups showed significant and similar increases in muscle strength (MJ-SJ = 16.4%; SJ-MJ = 12.7%) and mass (MJ-SJ = 7.5%; SJ-MJ = 6.1%), whereas there were no significant changes in testosterone and insulin-like growth factor 1. The results suggest that both approaches are similarly effective in eliciting morphofunctional improvements in older women.

The correlation of gagging threshold with intra-oral tactile and psychometric profiles in healthy subjects: A pilot study

Excessive gag reflex could be problematic for adequate dental care. Although various factors may increase the susceptibility to gagging, its contributing factors have not been fully determined. This study aimed to determine whether gag reflex was associated with tactile sensitivity and psychological characteristics. Fifteen volunteers of healthy males and females each were recruited for this study. After completing a questionnaire describing the self-perceived gag reflex activity, a disposable saliva ejector was inserted along the palate into the mouth until gagging was evoked. The ratio of the insertion depth to the palatal length was used as an index for the gagging threshold. The two-point discrimination (TPD) and Semmes-Weinstein monofilament (SWM) tests were performed to assess the tactile sensitivity of the palatal regions (hard palate, anterior and posterior soft palate). The Symptom Checklist-90-Revised was used to investigate the relationship between the gagging threshold and the psychological status. Our findings showed that the gagging threshold had a significant positive correlation with the TPD and SWM thresholds on the hard palate. The psychological profiles of psychoticism and hostility score were also significantly correlated with the gagging threshold. However, there were no significant differences in the tactile and gagging thresholds, as well as the psychological profiles, between males and females. Our results suggested that the tactile sensitivity of the anterior palate is a determining factor for the gagging threshold and implied that the initial response of the oral entry site to stimulation may lead to the development of gag reflex.

Single joint exercises do not provide benefits in performance and anthropometric changes in recreational bodybuilders

The purpose of the present study was to compare the changes in anthropometric measures and muscle performance in users and non-users of androgenic anabolic steroids (AAS) performing resistance training (RT) programmes involving only multiple joint (MJ) exercises or a combination of MJ and single joint (SJ) exercises. Thirty recreational bodybuilders were divided into 4 groups: non-AAS users performing only MJ exercises (MJ), non-AAS users performing MJ + SJ (MJ + SJ), AAS users performing only MJ exercises (AAS - MJ) and AAS users performing MJ + SJ exercises (AAS - MJ + SJ). Before and after 8 weeks of training, the participants were tested for 10 repetition maximum (10RM) in different RT exercises. Flexed arm circumference (FAC), biceps and triceps skinfolds were measured. No interactions were found between time and the performance of SJ exercise in any variable (p > .05). However, there was a significant interaction between AAS use and time (p < .001), such that AAS users showed greater 10RM gains in all exercises, skinfold decreases and increases in FAC than non-users. In conclusion, our study shows that the addition of SJ exercises to MJ exercises brings no additional benefit in terms of muscle performance and anthropometric changes in trained men, either if they were using AAS or not. These results suggest that trained men can save time not including SJ in their routines and still achieve optimal results. Moreover, our results show that AAS use is associated with greater increases in muscle strength and FAC and greater reductions in biceps and triceps skinfold thickness.

A Meta-Analysis of Resistance Training in Female Youth: Its Effect on Muscular Strength, and Shortcomings in the Literature

BACKGROUND

Resistance training is an effective way to enhance strength in female youth but, to date, no researcher has meta-analysed its effect on muscular strength in that population.

OBJECTIVES

This meta-analysis characterised female youths' adaptability to resistance training (RT). A second objective was to highlight the limitations of the body of literature with a view to informing future research.

DATA SOURCES

Google Scholar, PubMed, Web of Science.

STUDY ELIGIBILITY CRITERIA

Resistance training interventions in healthy females with a mean age between 8 and 18 years. Programmes of between 4 and 16 weeks' duration that included a control group.

STUDY APPRAISAL AND SYNTHESIS METHODS

The inverse-variance random effects model for meta-analyses was used because it allocates a proportionate weight to trials based on the size of their individual standard errors and facilitates analysis whilst accounting for heterogeneity across studies. Effect sizes, calculated from a measure of muscular strength, are represented by the standardised mean difference and are presented alongside 95% confidence intervals.

RESULTS

The magnitude of the main effect was 'small' (0.54, 95% confidence interval: 0.23-0.85). Effect sizes were larger in older (> 15 years; ES = 0.72 [0.23-1.21] vs. 0.38 [- 0.02-0.79]), taller (> 163 cm; ES = 0.67 [0.20-1.13] vs. 0.55 [0.08-1.02]) and heavier (< 54 kg; ES = 0.67 [0.30-1.03] vs. 0.53 [- 0.00-1.06]) participants.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

Resistance training is effective in female youth. These findings can be used to inform the prescription of RT in female youth.

A systematic review on the effects of resistance and plyometric training on physical fitness in youth- What do comparative studies tell us?

INTRODUCTION

To date, several meta-analyses clearly demonstrated that resistance and plyometric training are effective to improve physical fitness in children and adolescents. However, a methodological limitation of meta-analyses is that they synthesize results from different studies and hence ignore important differences across studies (i.e., mixing apples and oranges). Therefore, we aimed at examining comparative intervention studies that assessed the effects of age, sex, maturation, and resistance or plyometric training descriptors (e.g., training intensity, volume etc.) on measures of physical fitness while holding other variables constant.

METHODS

To identify relevant studies, we systematically searched multiple electronic databases (e.g., PubMed) from inception to March 2018. We included resistance and plyometric training studies in healthy young athletes and non-athletes aged 6 to 18 years that investigated the effects of moderator variables (e.g., age, maturity, sex, etc.) on components of physical fitness (i.e., muscle strength and power).

RESULTS

Our systematic literature search revealed a total of 75 eligible resistance and plyometric training studies, including 5,138 participants. Mean duration of resistance and plyometric training programs amounted to 8.9 ± 3.6 weeks and 7.1±1.4 weeks, respectively. Our findings showed that maturation affects plyometric and resistance training outcomes differently, with the former eliciting greater adaptations pre-peak height velocity (PHV) and the latter around- and post-PHV. Sex has no major impact on resistance training related outcomes (e.g., maximal strength, 10 repetition maximum). In terms of plyometric training, around-PHV boys appear to respond with larger performance improvements (e.g., jump height, jump distance) compared with girls. Different types of resistance training (e.g., body weight, free weights) are effective in improving measures of muscle strength (e.g., maximum voluntary contraction) in untrained children and adolescents. Effects of plyometric training in untrained youth primarily follow the principle of training specificity. Despite the fact that only 6 out of 75 comparative studies investigated resistance or plyometric training in trained individuals, positive effects were reported in all 6 studies (e.g., maximum strength and vertical jump height, respectively).

CONCLUSIONS

The present review article identified research gaps (e.g., training descriptors, modern alternative training modalities) that should be addressed in future comparative studies.

Effectiveness of Traditional Strength vs. Power Training on Muscle Strength, Power and Speed with Youth: A Systematic Review and Meta-Analysis

Numerous national associations and multiple reviews have documented the safety and efficacy of strength training for children and adolescents. The literature highlights the significant training-induced increases in strength associated with youth strength training. However, the effectiveness of youth strength training programs to improve power measures is not as clear. This discrepancy may be related to training and testing specificity. Most prior youth strength training programs emphasized lower intensity resistance with relatively slow movements. Since power activities typically involve higher intensity, explosive-like contractions with higher angular velocities (e.g., plyometrics), there is a conflict between the training medium and testing measures. This meta-analysis compared strength (e.g., training with resistance or body mass) and power training programs (e.g., plyometric training) on proxies of muscle strength, power, and speed. A systematic literature search using a Boolean Search Strategy was conducted in the electronic databases PubMed, SPORT Discus, Web of Science, and Google Scholar and revealed 652 hits. After perusal of title, abstract, and full text, 107 studies were eligible for inclusion in this systematic review and meta-analysis. The meta-analysis showed small to moderate magnitude changes for training specificity with jump measures. In other words, power training was more effective than strength training for improving youth jump height. For sprint measures, strength training was more effective than power training with youth. Furthermore, strength training exhibited consistently large magnitude changes to lower body strength measures, which contrasted with the generally trivial, small and moderate magnitude training improvements of power training upon lower body strength, sprint and jump measures, respectively. Maturity related inadequacies in eccentric strength and balance might influence the lack of training specificity with the unilateral landings and propulsions associated with sprinting. Based on this meta-analysis, strength training should be incorporated prior to power training in order to establish an adequate foundation of strength for power training activities.

Muscle activation during resistance training with no external load - effects of training status, movement velocity, dominance, and visual feedback

OBJECTIVES

To explore the acute effects of training status, movement velocity, dominance, and visual feedback on muscle activation and rating of perceived exertion (RPE) during resistance training with no external load (no-load resistance training; NLRT).

METHODS

Thirty-three men (17 untrained and 16 trained), performed elbow flexions in four NLRT sessions: 1) slow velocity with EMG visual feedback, 2) slow velocity without EMG visual feedback, 3) fast velocity with EMG feedback, and 4) fast velocity without EMG feedback. RPE was measured using the Borg Discomfort scale. EMG for the biceps and triceps were recorded for both arms.

RESULTS

EMG feedback had no influence on RPE. The peak and mean EMG values were not different for the biceps (93.8±11.5% and 50±13.1%) and triceps (93.7±23.9% and 49.6±16.2%). The results revealed a difference in the training status, with higher peak EMG for untrained than for trained participants (96.9±20% vs. 90.2±15.6%). However the values for mean EMG were not different between the untrained and trained (50.3±15.7% vs. 49.2±13.7%) participants. There was no difference in the peak (92.8±19% vs. 94.7±20.4%) and mean (49.8±15.0% vs. 49.7±14.5%) EMG values for the dominant and non-dominant sides. Peak EMG values were not different between faster and slower velocities (93.6±19.6% and 93.9±17.8%). However, mean EMG was higher for slower (50.5±14.4%) than for faster (48.5±15.4%) velocities. The peak and mean EMG during contractions with (93.3±17.5% and 49.5±14.1%) and without visual feedback (94.2±19.9% and 50±15.4%) were not significantly different.

CONCLUSION

NLRT produces high levels of muscle activation independent of training, status, dominance, movement velocity, and visual feedback.