Maximal Number of Repetitions at Percentages of the One Repetition Maximum: A Meta-Regression and Moderator Analysis of Sex, Age, Training Status, and Exercise

The maximal number of repetitions that can be completed at various percentages of the one repetition maximum (1RM) [REPS ~ %1RM relationship] is foundational knowledge in resistance exercise programming. The current REPS ~ %1RM relationship is based on few studies and has not incorporated uncertainty into estimations or accounted for between-individuals variation. Therefore, we conducted a meta-regression to estimate the mean and between-individuals standard deviation of the number of repetitions that can be completed at various percentages of 1RM. We also explored if the REPS ~ %1RM relationship is moderated by sex, age, training status, and/or exercise. A total of 952 repetitions-to-failure tests, completed by 7289 individuals in 452 groups from 269 studies, were identified. Study groups were predominantly male (66%), healthy (97%), < 59 years of age (92%), and resistance trained (60%). The bench press (42%) and leg press (14%) were the most commonly studied exercises. The REPS ~ %1RM relationship for mean repetitions and standard deviation of repetitions were best described using natural cubic splines and a linear model, respectively, with mean and standard deviation for repetitions decreasing with increasing %1RM. More repetitions were evident in the leg press than bench press across the loading spectrum, thus separate REPS ~ %1RM tables were developed for these two exercises. Analysis of moderators suggested little influences of sex, age, or training status on the REPS ~ %1RM relationship, thus the general main model REPS ~ %1RM table can be applied to all individuals and to all exercises other than the bench press and leg press. More data are needed to develop REPS ~ %1RM tables for other exercises.

Using Powerlifting Athletes to Determine Strength Adaptations Across Ages in Males and Females: A Longitudinal Growth Modelling Approach

INTRODUCTION

Several retrospective studies of strength sport athletes have reported strength adaptations over months to years; however, such adaptations are not linear.

METHODS

We explored changes in strength over time in a large, retrospective sample of powerlifting (PL) athletes. Specifically, we examined the rate and magnitude of strength adaptation based on age category and weight class for PL competition total, and the squat, bench press, and deadlift, respectively. Mixed effects growth modelling was performed for each operationalised performance outcome (squat, bench press, deadlift, and total) as the dependent variables, with outcomes presented on both the raw, untransformed time scale and on the common logarithmic scale. Additionally, the fitted values were rescaled as a percentage.

RESULTS

Collectively, the greatest strength gains were in the earliest phase of PL participation (~ 7.5-12.5% increase in the first year, and up to an ~ 20% increase after 10 years). Females tended to display faster progression, possibly because of lower baseline strength. Additionally, female Masters 3 and 4 athletes (> 59 years) still displayed ~ 2.5-5.0% strength improvement, but a slight strength loss was observed in Masters 4 (> 69 years) males (~ 0.35%/year).

CONCLUSION

Although directly applicable to PL, these findings provide population-level support for the role of consistent and continued strength training to improve strength across the age span and, importantly, to mitigate, or at least largely attenuate age-related declines in strength compared to established general population norms. This information should be used to encourage participation in strength sports, resistance training more generally, and to support future public health messaging.

The Effects of Training Load During Dietary Intervention Upon Fat Loss: A Randomized Crossover Trial

Purpose: To date no studies have compared resistance training loading strategies combined with dietary intervention for fat loss. Methods: Thus, we performed a randomised crossover design comparing four weeks of heavier- (HL; ~80% 1RM) and lighter-load (LL; ~60% 1RM) resistance training, combined with calorie restriction and dietary guidance, including resistance trained participants (n=130; males=49, females=81). Both conditions performed low-volume, (single set of 9 exercises, 2x/week) effort matched (to momentary failure), but non-work-matched protocols. Testing was completed pre- and post-each intervention. Fat mass (kg) was the primary outcome, and a smallest effect size of interest (SESOI) was established at 3.3% loss of baseline bodyweight. Body fat percentage, lean mass, and strength (7-10RM) for chest press, leg press, and pull-down exercises were also measured. An 8-week washout period of traditional training with normal calorie interspersed each intervention. Results: Both interventions showed small statistically equivalent (within the SESOI) reductions in fat mass (HL: -0.67 kg [95%CI -0.91 to 0.42]; LL: -0.55 kg [95%CI -0.80 to -0.31]) which were also equivalent between conditions (HL - LL: -0.113 kg [95%CI -0.437 kg to 0.212 kg]). Changes in body fat percentage and lean mass were also minimal. Strength increases were small, similar between conditions, and within a previously determined SESOI for the population included (10.1%). Conclusions: Fat loss reductions are not impacted by resistance training load; both HL and LL produce similar, yet small, changes to body composition over a 4-week intervention. However, the maintenance of both lean mass and strength highlights the value of resistance training during dietary intervention.

Long-Term Time-Course of Strength Adaptation to Minimal Dose Resistance Training Through Retrospective Longitudinal Growth Modeling

Public health guidelines for resistance training emphasize a minimal effective dose intending for individuals to engage in these behaviors long term. However, few studies have adequately examined the longitudinal time-course of strength adaptations to resistance training. Purpose: The aim of this study was to examine the time-course of strength development from minimal-dose resistance training in a large sample through retrospective training records from a private international exercise company. Methods: Data were available for analysis from 14,690 participants (60% female; aged 48 ± 11 years) having undergone minimal-dose resistance training (1x/week, single sets to momentary failure of six exercises) up to 352 weeks (~6.8 years) in length. Linear-log growth models examined strength development over time allowing random intercepts and slopes by participant. Results: All models demonstrated a robust linear-log relationship with the first derivatives (i.e., changes in strength with time) trending asymptotically such that by ~1-2 years strength had practically reached a "plateau." Sex, bodyweight, and age had minimal interaction effects. However, substantial strength gains were apparent; approximately ~30-50% gains over the first year reaching ~50-60% of baseline 6 years later. Conclusion: It is unclear if the "plateau" can be overcome through alternative approaches, or whether over the long-term strength gains differ. Considering this, our results support public health recommendations for minimal-dose resistance training for strength adaptations in adults.

Hybrid delivery of cluster-set resistance training for individuals previously treated for lung cancer: the results of a single-arm feasibility trial

BACKGROUND

Individuals with non-small cell lung cancer (NSCLC) are burdened by long-lasting symptoms (e.g., dyspnea and fatigue) post-treatment. These symptoms often reduce physical activity levels and increase the risk of functional decline. Though we have previously proposed cluster-set resistance training to mitigate symptom burden in lung cancer, there is currently no data on the feasibility or acceptability of this mode of exercise in cancer. Therefore, the purpose of this study was to investigate the feasibility and acceptability of a hybrid-delivery home-based cluster-set resistance training program in individuals with NSCLC stages I-III (i.e., early stage).

METHODS

This study aimed to recruit individuals with NSCLC stages I-III post-treatment to participate in 8 weeks of home-based resistance training, 3 days per week. The program included supervised sessions in the participants' homes and virtual supervision via videoconferencing. The primary outcome measure of feasibility was evaluated through recruitment, retention, and intervention fidelity (i.e., proportion of exercise completed, relative to what was prescribed). Intervention acceptability (i.e., ease and quality of virtual delivery, level of difficulty, and home-based approach) was assessed using a 4-point Likert-type scale from "strongly disagree" to "strongly agree".

RESULTS

Fourteen participants were recruited over a 6-month period, with 11 completing the intervention (2 withdrew due to unrelated illness, 1 withdrew due to requiring active treatment), yielding a retention rate of 79%. Characteristics of the participants who completed the intervention (n = 11) were as follows: mean age: 71 ± 10 years, mean BMI: 29.1 ± 6.5, and average time since diagnosis was 62 ± 51 months. Of completers, 27% were male, and 36% were Black; 10 were stage I (91%), and one was stage II (9%). Mean session attendance was 86.4 ± 9.5%. Mean intervention fidelity was 83.1 ± 13.1%. With regard to acceptability,  > 90% of participants positively rated all aspects of the intervention delivery. No adverse events related to exercise were recorded.

CONCLUSIONS

The hybrid delivery of a home-based resistance exercise program for individuals previously treated for early-stage NSCLC was found to be safe and feasible. Adaptations to the program for future interventions are required, particularly surrounding resistance exercise programming, and intervention delivery with home visits.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT05014035 . Registered January 20, 2021.

Surface electromyographic frequency characteristics of the quadriceps differ between continuous high- and low-torque isometric knee extension to momentary failure

Surface EMG (sEMG) has been used to compare loading conditions during exercise. Studies often explore mean/median frequencies. This potentially misses more nuanced electrophysiological differences between exercise tasks. Therefore, wavelet-based analysis was used to evaluate electrophysiological characteristics in the sEMG signal of the quadriceps under both higher- and lower-torque (70 % and 30 % of MVC, respectively) isometric knee extension performed to momentary failure. Ten recreationally active adult males with previous resistance training experience were recruited. Using a within-session, repeated-measures, randomised crossover design, participants performed isometric knee extension whilst sEMG was collected from the vastus medialis (VM), rectus femoris (RF) and vastus lateralis (VL). Mean signal frequency showed similar characteristics in each condition at momentary failure. However, individual wavelets revealed different frequency component changes between the conditions. All frequency components increased during the low-torque condition. But low-frequency components increased, and high-frequency components decreased, in intensity throughout the high-torque condition. This resulted in convergence of the low-torque and high-torque trial wavelet characteristics towards the end of the low-torque trial. Our results demonstrate a convergence of myoelectric signal properties between low- and high-torque efforts with fatigue via divergent signal adaptations. Further work should disentangle factors influencing frequency characteristics during exercise tasks.

Meta-analysis of variation in sport and exercise science: Examples of application within resistance training research

Meta-analysis has become commonplace within sport and exercise science for synthesising and summarising empirical studies. However, most research in the field focuses upon mean effects, particularly the effects of interventions to improve outcomes such as fitness or performance. It is thought that individual responses to interventions vary considerably. Hence, interest has increased in exploring precision or personalised exercise approaches. Not only is the mean often affected by interventions, but variation may also be impacted. Exploration of variation in studies such as randomised controlled trials (RCTs) can yield insight into interindividual heterogeneity in response to interventions and help determine generalisability of effects. Yet, larger samples sizes than those used for typical mean effects are required when probing variation. Thus, in a field with small samples such as sport and exercise science, exploration of variation through a meta-analytic framework is appealing. Despite the value of embracing and exploring variation alongside mean effects in sport and exercise science, it is rarely applied to research synthesis through meta-analysis. We introduce and evaluate different effect size calculations along with models for meta-analysis of variation using relatable examples from resistance training RCTs.

The Eccentric:Concentric Strength Ratio of Human Skeletal Muscle In Vivo: Meta-analysis of the Influences of Sex, Age, Joint Action, and Velocity

For decades, researchers have observed that eccentric (ECC) muscle strength is greater than concentric (CON) muscle strength. However, knowledge of the ECC:CON strength ratio is incomplete and might inform resistance exercise prescriptions. Our purposes were to determine the magnitude of the ECC:CON ratio of human skeletal muscle in vivo and explore if sex, age, joint actions/exercises, and movement velocity impact it. A total of 340 studies were identified through searches. It was possible to analyse 1516 ECC:CON ratios, aggregated from 12,546 individuals who made up 564 groups in 335 of the identified studies. Approximately 98% of measurements occurred on isokinetic machines. Bayesian meta-analyses were performed using log-ratios as response variables then exponentiated back to raw ratios. The overall main model estimate for the ECC:CON ratio was 1.41 (95% credible interval [CI] 1.38-1.44). The ECC:CON ratio was slightly less in men (1.38 [CI 1.34-1.41]) than women (1.47 [CI 1.43-1.51]), and greater in older adults (1.62 [CI 1.57-1.68]) than younger adults (1.39 [CI 1.36-1.42]). The ratio was similar between grouped upper-body (1.42 [CI 1.38-1.46]) and lower-body joint actions/exercises (1.40 [CI 1.37-1.44]). However, heterogeneity in the ratio existed across joint actions/exercises, with point estimates ranging from 1.32 to 2.61. The ECC:CON ratio was most greatly impacted by movement velocity, with a 0.20% increase in the ratio for every 1°/s increase in velocity. The results show that ECC muscle strength is ~ 40% greater than CON muscle strength. However, the ECC:CON ratio is greatly affected by movement velocity and to lesser extents age and sex. Differences between joint actions/exercises likely exist, but more data are needed to provide more precise estimates.

"I Felt I Was Actually Inside the Movie" An Exploratory Study into Children's Views of Staging a Physically Active Experience, with Implications for Future Interventions

Current levels of inactivity suggest novel approaches are needed to engage children in physical activity (PA), and enjoyment is a strong motivator for children's PA engagement. A physically active experience (PAE) was proposed as a way to use entertainment, education, (e)aesthetics and escapist methods to promote PA to children in a way that is immersive and enables them to actively partake whilst enjoying their experience. In this current mixed methods study, three physically active experiences based on popular children's movies were designed and staged, in order to explore children's views on staging a PAE and provide implications for future PA interventions. Seventeen children (boys n = nine, girls n = eight) between the ages of nine and ten years provided feedback on the experiences. The children watched a pre-recorded video presenting the physically active experiences and then completed a survey including affective forecasting responses, which was followed by participation in an online focus group where views on the experiences were explored further. For all three experiences, the mean anticipated affective response for valence was between "fairly good" and "good", and for arousal between "a bit awake" and "awake". Further, when asked, the children reported wanting to take part in the experiences (experience 1: 82.4%, experience 2: 76.5%, experience 3: 64.7%). The qualitative data revealed that children felt that they would enjoy the sessions, feel immersed in their environment, transported away from reality, and that they would be able to learn something new regarding PA. These results support the implementation of a PAE to engage children in enjoyable PA; future interventions should use these findings to engage children in a PAE, examining their actual responses to the activities.

Pharmacological Blockade of Muscle Afferents and Perception of Effort: A Systematic Review with Meta-analysis

BACKGROUND

The perception of effort provides information on task difficulty and influences physical exercise regulation and human behavior. This perception differs from other-exercise related perceptions such as pain. There is no consensus on the role of group III/IV muscle afferents as a signal processed by the brain to generate the perception of effort.

OBJECTIVE

The aim of this meta-analysis was to investigate the effect of pharmacologically blocking muscle afferents on the perception of effort.

METHODS

Six databases were searched to identify studies measuring the ratings of perceived effort during physical exercise, with and without pharmacological blockade of muscle afferents. Articles were coded based on the operational measurement used to distinguish studies in which perception of effort was assessed specifically (effort dissociated) or as a composite experience including other exercise-related perceptions (effort not dissociated). Articles that did not provide enough information for coding were assigned to the unclear group.

RESULTS

The effort dissociated group (n = 6) demonstrated a slight increase in ratings of perceived effort with reduced muscle afferent feedback (standard mean change raw, 0.39; 95% confidence interval 0.13-0.64). The group effort not dissociated (n = 2) did not reveal conclusive results (standard mean change raw, - 0.29; 95% confidence interval - 2.39 to 1.8). The group unclear (n = 8) revealed a slight ratings of perceived effort decrease with reduced muscle afferent feedback (standard mean change raw, - 0.27; 95% confidence interval - 0.50 to - 0.04).

CONCLUSIONS

The heterogeneity in results between groups reveals that the inclusion of perceptions other than effort in its rating influences the ratings of perceived effort reported by the participants. The absence of decreased ratings of perceived effort in the effort dissociated group suggests that muscle afferent feedback is not a sensory signal for the perception of effort.

The impact of signposting and group support pathways on a community-based physical activity intervention grounded in motivational interviewing

BACKGROUND

Brief advice is recommended to increase physical activity (PA) within primary care. This study assessed change in PA levels and mental well-being after a motivational interviewing (MI) community-based PA intervention and the impact of signposting (SP) and social action (SA) (i.e. weekly group support) pathways.

METHODS

Participants (n = 2084) took part in a community-based, primary care PA programme using MI techniques. Self-reported PA and mental well-being data were collected at baseline (following an initial 30-min MI appointment), 12 weeks, 6 months and 12 months. Participants were assigned based upon the surgery they attended to the SP or SA pathway. Multilevel models derived point estimates and 95% confidence intervals for outcomes at each time point and change scores.

RESULTS

Participants increased PA and mental well-being at each follow-up time point through both participant pathways and with little difference between pathways. Retention was similar between pathways at 12 weeks, but the SP pathway retained more participants at 6 and 12 months.

CONCLUSIONS

Both pathways produced similar improvements in PA and mental well-being; however, the addition of a control would have provided further insight as to the effectiveness. Due to lower resources yet similar effects, the SP pathway could be incorporated to support PA in primary care settings.

The impact of signposting and group support pathways on a community-based physical activity intervention grounded in motivational interviewing

BACKGROUND

Brief advice is recommended to increase physical activity (PA) within primary care. This study assessed change in PA levels and mental well-being after a motivational interviewing (MI) community-based PA intervention and the impact of signposting (SP) and social action (SA) (i.e. weekly group support) pathways.

METHODS

Participants (n = 2084) took part in a community-based, primary care PA programme using MI techniques. Self-reported PA and mental well-being data were collected at baseline (following an initial 30-min MI appointment), 12 weeks, 6 months and 12 months. Participants were assigned based upon the surgery they attended to the SP or SA pathway. Multilevel models derived point estimates and 95% confidence intervals for outcomes at each time point and change scores.

RESULTS

Participants increased PA and mental well-being at each follow-up time point through both participant pathways and with little difference between pathways. Retention was similar between pathways at 12 weeks, but the SP pathway retained more participants at 6 and 12 months.

CONCLUSIONS

Both pathways produced similar improvements in PA and mental well-being; however, the addition of a control would have provided further insight as to the effectiveness. Due to lower resources yet similar effects, the SP pathway could be incorporated to support PA in primary care settings.

'A Physically Active Experience': Setting the Stage for a New Approach to Engage Children in Physical Activity Using Themed Entertainment Experiences

Despite the multiple health benefits that result from engaging in physical activity, data suggest that children are moving less. Novel approaches to engaging children in physical activity are needed to address this public health concern. Recently, a new definition of physical activity was proposed that emphasizes, among other things, the fact that physical activity is deeply affective, emotional and situated in spaces that shape the experience. With the need to increase engagement in physical activity and this new proposed definition, this paper presents a more novel approach to addressing this problem through staging a physically active experience. The idea draws upon the well-established area of experience economy, which aims to engage those partaking in an educational, (e)aesthetic, escapist, and entertaining way. When staging something as an experience, the focus is on engagement. By staging physical activity as an experience, it is proposed that children can actively partake in physical activity in a way that is focused on the experience offered. This review explains the notion of experience economy and provides examples of how it could be applied to children's physical activity. By creating an aesthetically pleasing, escapist and entertaining environment where children can learn and engage in physical activity, a more engaging positive experience of physical activity can be offered. Future research should examine the staging of physically active experiences for children and evaluate the practical implementation and effectiveness of this new approach to increasing children's engagement in physical activity.

O-028 Small extracellular vesicles (sEV) in peritoneal fluid and peripheral blood as biomarkers of endometriosis

Study question

Can we identify lesion-derived endometriosis-specific sEV cargo in peritoneal fluid of women with endometriosis, and detect the same endometriosis-specific cargo in sEV from peripheral blood?

Summary answer

Endometriosis-specific sEV are present in PF. Identification in peripheral blood is challenging due to low abundance in comparison to blood-borne sEV.

What is known already

Endometriosis is characterised by intraperitoneal lesions of endometrial tissue. Although ultrasound detection of severe endometriosis is possible, the final diagnosis currently relies on invasive laparoscopy as the gold standard, which leads to a delay of 8-10 years after women first present to their GPs with symptoms.

We have previously shown that the peritoneal fluid (PF) of women with endometriosis contains endometriosis-specific sEV. If these can be traced in blood samples, endometriosis-specific sEV could serve as biomarkers of endometriosis, particularly for stages I and II, which are difficult to detect by ultrasound.

Study design, size, duration

This is an observational pilot study of 29 patients in total. From March 2021 until August 2021, we collected PF samples from 11 controls and 16 endometriosis cases and blood samples from 12 controls and 11 endometriosis cases. Of these, 19 were paired samples (blood and PF from the same participant).

Participants/materials, setting, methods

Women &gt;18 years of age undergoing laparoscopic surgery for endometriosis or unrelated conditions were invited to participate (HREC 08078B/HREC 10148B). Exclusion criteria were pregnancy, malignancy, and menopause. Purified, validated sEV were analysed by label based quantitative proteomics Tandem Mass Tag (TMT). Data analysis was performed using Proteome Discoverer v2.4 (Thermo Fisher), statistical analysis using the R (LIMMA), with a protein false discovery rate of 1% and a quantitative threshold of an adjusted p-value &lt;0.05.

Main results and the role of chance

We ascertained the identity of sEV by TEM and NTA (mode size 121.8 ± 18.0 nm (blood, n = 5) and 155.9 ± 37.2 (PF, n = 6)), and signals for syntenin and ALIX in immunoblots as well as expression of CD9, CD63 and CD81 in capture bead-flow cytometry. Proteomics analysis identified 9145 proteins groups across all sample groups, of these proteins 5,429 are consistently quantifiable, with 602 significantly different between comparisons (adjusted P-value &lt;0.05). PCA showed separation of samples by type rather than batch. Fractionated analysis by SPS-MS3 methodology identified 7064 protein groups, with 3408 proteins consistently quantified across sample groups. Of these, 602 were found to differ significantly across all comparisons. In PF, 533 proteins changed significantly in abundance (245 up and 288 down), while in blood, four proteins changed in abundance.

Limitations, reasons for caution

The main limitation of the study is in its small sample size, which meant that we could not stratify data according to endometriosis stage. Due to limited amount of protein within sEV samples, not all assays could be done on all samples.

Wider implications of the findings

Our findings suggest that our methodology makes it feasible to define a protein signature of endometriosis based on sEV cargoes drawn from blood samples. This would represent a non-invasive biomarker of endometriosis and could help diagnose the condition, or rule out endometriosis as the origin of symptoms in the future.

Trial registration number

not applicable

Study protocol: investigating the feasibility of a hybrid delivery of home-based cluster set resistance training for individuals previously treated for lung cancer

Background

Symptom burden remains a critical concern for individuals with non-small cell lung cancer (NSCLC) following the completion of treatment. The most common symptom clusters, dyspnea (shortness of breath) and fatigue, can contribute to physical decline, reductions in quality of life, and a higher risk of comorbidities and mortality. Dyspnea is a primary limiter of exercise capacity in individuals with lung cancer, resulting in exercise avoidance and an accelerated physical decline. As such, designing resistance training with cluster sets to mitigate symptoms of dyspnea and fatigue may result in improved exercise tolerance. Thus, maintaining the exercise stimulus via cluster sets, combined with improved tolerance of the exercise, could result in the maintenance of physical function and quality of life. The purpose of this study is to investigate the feasibility and preliminary efficacy of a hybrid-delivery home-based cluster-set resistance training program in individuals with NSCLC.

Methods

Individuals with NSCLC (n = 15), within 12 months of completion of treatment, will be recruited to participate in this single-arm feasibility trial. Participants will complete 8 weeks of home-based resistance training designed to minimize dyspnea and fatigue. The hybrid delivery of the program will include supervised sessions in the participants’ home and virtual supervision via video conferencing. The primary outcome of feasibility will be quantified by recruitment rates, retention, acceptability, and intervention fidelity. Exploratory outcomes (dyspnea, fatigue, quality of life, physical function, and body composition) will be assessed pre- and post-intervention.

Discussion

This study will provide important data on the feasibility of delivering this intervention and inform procedures for a future randomized controlled trial.

Trial registration

Record not yet public

Comparison of Power Training vs Traditional Strength Training on Physical Function in Older Adults: A Systematic Review and Meta-analysis

IMPORTANCE

Strength training exercise is recommended for improving physical function in older adults. However, whether strength training (lifting and lowering weights under control) and power training (PT) (lifting weights fast and lowering under control) are associated with improved physical function in older adults is not clear.

OBJECTIVE

To evaluate whether PT vs traditional strength training is associated with physical function improvement in older adults.

DATA SOURCES

Systematic searches of MEDLINE, Embase, Cochrane Central, CINAHL, PsycInfo, PEDro, and SPORTDiscus were conducted from database inception to October 20, 2021.

STUDY SELECTION

Randomized clinical trials (RCTs) that compared strength training with instructions to move the weight as fast as possible in the lifting phase with traditional strength training in healthy, community-living older adults (age ≥60 years).

DATA EXTRACTION AND SYNTHESIS

Two authors independently selected trials, extracted data, assessed the risk of bias using the Cochrane risk-of-bias tool 2, and assessed the certainty of the evidence using the Grading of Recommendations, Assessment, Development and Evaluation approach. Summary effect size measures were calculated using a multilevel random-effects model with cluster robust variance estimation and are reported as standardized mean differences (SMDs). Reporting followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline.

MAIN OUTCOMES AND MEASURES

Primary outcomes included physical function and self-reported physical function. Secondary outcomes included power, strength, muscle mass, walk speed, balance, and adverse effects.

RESULTS

A total of 20 RCTs enrolling 566 community-living older adults (mean [SD] age, 70.1 [4.8] years; 368 [65%] women) were included. For the primary outcomes, PT was associated with an improvement in physical function with low-certainty evidence in 13 RCTs (n = 383) (SMD, 0.30; 95% CI, 0.05-0.54) and self-reported function with low-certainty evidence in 3 RCTs (n = 85) (SMD, 0.38; 95% CI, -0.62 to 1.37). The evidence was downgraded by 2 levels for high risk of bias and imprecision for physical function and very serious imprecision for self-reported physical function.

CONCLUSIONS AND RELEVANCE

In this systematic review and meta-analysis, PT was associated with a modest improvement in physical function compared with traditional strength training in healthy, community-living older adults. However, high-quality, larger RCTs are required to draw more definitive conclusions.

Comparison of the effects of velocity-based vs. traditional resistance training methods on adaptations in strength, power, and sprint speed: A systematic review, meta-analysis, and quality of evidence appraisal

We estimated the effectiveness of using velocity feedback to regulate resistance training load on changes in muscle strength, power, and linear sprint speed in apparently healthy participants. Academic and grey literature databases were systematically searched to identify randomised trials that compared a velocity-based training intervention to a 'traditional' resistance training intervention that did not use velocity feedback. Standardised mean differences (SMDs) were pooled using a random effects model. Risk of bias was assessed with the Risk of Bias 2 tool and the quality of evidence was evaluated using the GRADE approach. Four trials met the eligibility criteria, comprising 27 effect estimates and 88 participants. The main analyses showed trivial differences and imprecise interval estimates for effects on muscle strength (SMD 0.06, 95% CI -0.51-0.63; I² = 42.9%; 10 effects from 4 studies; low-quality evidence), power (SMD 0.11, 95% CI -0.28-0.49; I² = 13.5%; 10 effects from 3 studies; low-quality evidence), and sprint speed (SMD -0.10, 95% CI -0.72-0.53; I² = 30.0%; 7 effects from 2 studies; very low-quality evidence). The results were robust to various sensitivity analyses. In conclusion, there is currently no evidence that VBT and traditional resistance training methods lead to different alterations in muscle strength, power, or linear sprint speed.

The effects of adding high-intensity of effort resistance training to routine care in persons with type II diabetes: An exploratory randomized parallel-group time-series study

AIMS

This study considered the effects of supervised, low volume, high intensity of effort resistance training compared to continued routine care in persons with type II diabetes.

METHODS

We utilized a randomized parallel-group time-series design. All participants completed baseline testing (T0) and then participated in an educational training intervention regarding the management of their diabetes and were followed up for six months, during which they received routine care before being retested (T1). Participants were then randomly allocated to either continue with routine care (CON) or receive the high intensity of effort resistance training intervention (HIT). Participants from both groups were retested again after six months (T2). All participants were followed up for a further 12 months before being finally tested (T3). Data were available from 57 participants who completed the whole duration of the study (HIT, n = 29; CON, n = 28) for measures of anthropometry (body mass, waist circumference, and BMI), body composition (body fat mass, body fat percentage, lean mass, and visceral fat mass), total body water, phase angle, HbA1c, fasted blood glucose, and subjective wellbeing (WHO-5).

RESULTS

During the initial 6-months of routine care significant improvements were noted for waist circumference, body fat mass, lean mass, body fat percentage, lean mass percentage, visceral fat mass, HbA1c, fasted blood glucose, and subjective wellbeing. During the successive 6-months (intervention) and 18-months (follow-up), data suggest that many of these positive changes during the initial 6-months were negated or reversed for CON. In contrast, participants engaging in HIT continued to show positive changes for waist circumference, body fat mass, lean mass, body fat percentage, lean mass percentage, and visceral fat. For blood markers and wellbeing, HbA1c continued to decrease, fasted blood glucose decreased, and subjective wellbeing continued to increase. These positive responses were still evidenced and significantly different compared to CON after the 12-month follow-up.

CONCLUSION

The results of this exploratory pragmatic trial suggest that the addition of high intensity of effort RT alongside routine care can have a positive impact on a range of outcomes in type 2 diabetics having undergone prior routine care.

Cycle ergometer training and resistance training similarly increase muscle strength in trained men

The aim of this study was to compare two different maximal intensity exercise modality training protocols of similar durations on muscle strength, cardiorespiratory fitness, and lower limb composition in recreationally trained men. Twenty-five trained men (28.9 ± 5.6 years) were randomly divided into Cycle ergometer (4 sets of 30 seconds sprints) and Leg press (4 sets of 10-12 repetitions to momentary failure). Both groups trained three times a week for 5 weeks. Before and after the training period, the participants performed a 10-repetition maximum (10RM) test for knee extension, an incremental exercise test on a treadmill for time to exhaustion (TTE) and peak oxygen consumption (V˙O_2peak) and underwent dual energy X-ray absorptiometry to assess lower limb composition. Knee extension 10RM and TTE increased in both groups with no statistically significant between group (p = 0.614 and p = 0.210). Only cycle ergometer group increased V˙O_2peak (p ₌ 0,012). For all lower limb composition outcomes, changes were minimal. The results suggest that 5 weeks of effort and duration matched exercise protocols using cycle ergometer training or leg press may produce similar strength adaptations.

Accuracy in Predicting Repetitions to Task Failure in Resistance Exercise: A Scoping Review and Exploratory Meta-analysis

BACKGROUND

Prescribing repetitions relative to task failure is an emerging approach to resistance training. Under this approach, participants terminate the set based on their prediction of the remaining repetitions left to task failure. While this approach holds promise, an important step in its development is to determine how accurate participants are in their predictions. That is, what is the difference between the predicted and actual number of repetitions remaining to task failure, which ideally should be as small as possible.

OBJECTIVE

The aim of this study was to examine the accuracy in predicting repetitions to task failure in resistance exercises.

DESIGN

Scoping review and exploratory meta-analysis.

SEARCH AND INCLUSION

A systematic literature search was conducted in January 2021 using the PubMed, SPORTDiscus, and Google Scholar databases. Inclusion criteria included studies with healthy participants who predicted the number of repetitions they can complete to task failure in various resistance exercises, before or during an ongoing set, which was performed to task failure. Sixteen publications were eligible for inclusion, of which 13 publications covering 12 studies, with a total of 414 participants, were included in our meta-analysis.

RESULTS

The main multilevel meta-analysis model including all effects sizes (262 across 12 clusters) revealed that participants tended to underpredict the number of repetitions to task failure by 0.95 repetitions (95% confidence interval [CI] 0.17-1.73), but with considerable heterogeneity (Q₍₂₆₁₎ = 3060, p < 0.0001, I² = 97.9%). Meta-regressions showed that prediction accuracy slightly improved when the predictions were made closer to set failure (β =  - 0.025, 95% CI - 0.05 to 0.0014) and when the number of repetitions performed to task failure was lower (≤ 12 repetitions: β = 0.06, 95% CI 0.04-0.09; > 12 repetitions: β = 0.47, 95% CI 0.44-0.49). Set number trivially influenced prediction accuracy with slightly increased accuracy in later sets (β =  - 0.07 repetitions, 95% CI - 0.14 to - 0.005). In contrast, participants' training status did not seem to influence prediction accuracy (β =  - 0.006 repetitions, 95% CI - 0.02 to 0.007) and neither did the implementation of upper or lower body exercises (upper body - lower body =  - 0.58 repetitions; 95% CI - 2.32 to 1.16). Furthermore, there was minimal between-participant variation in predictive accuracy (standard deviation 1.45 repetitions, 95% CI 0.99-2.12).

CONCLUSIONS

Participants were imperfect in their ability to predict proximity to task failure independent of their training background. It remains to be determined whether the observed degree of inaccuracy should be considered acceptable. Despite this, prediction accuracies can be improved if they are provided closer to task failure, when using heavier loads, or in later sets. To reduce the heterogeneity between studies, future studies should include a clear and detailed account of how task failure was explained to participants and how it was confirmed.

Lighter-Load Exercise Produces Greater Acute- and Prolonged-Fatigue in Exercised and Non-Exercised Limbs

Purpose: The present study compared the fatigue and perceptual responses to volume-load matched heavier- and lighter- load resistance exercise to momentary failure in both a local/exercised, and non-local/non-exercised limb. Methods: Eleven resistance-trained men undertook unilateral maximal voluntary contraction (MVC) testing for knee extension prior to and immediately, 24 hr- and 48 hr- post heavier (80% MVC) and lighter  (40% MVC) load dynamic unilateral knee extension exercise. Only the dominant leg of each participant was exercised to momentary failure using heavier and lighter loads, and perceptions of discomfort were measured immediately upon exercise cessation. Results: Point estimates and confidence intervals suggested that immediately post-exercise there was greater fatigue in both the exercised and non-exercised legs for the lighter- load condition. At 24 hr the exercised leg under the heavier-load condition had recovered to pre-exercise strength; however, the exercised leg under lighter- load condition had still not fully recovered by 48 hr. For the non-exercised leg, only the lighter-load condition induced fatigue; however, recovery had occurred by 48 hr. Median discomfort ratings were statistically significantly different (Z = -2.232, p = .026) between lighter and heavier loads (10 [IQR = 0] and 8 [IQR = 3], respectively). Conclusions: This study suggests that lighter-load resistance exercise induces greater fatigue in both the exercised- and non-exercised limbs, compared to heavier-load resistance exercise. These findings may have implications for exercise frequency as it may be possible to engage in heavier-load resistance exercise more frequently than a volume-load matched protocol using lighter loads.Abbreviations CI: Confidence intervals: ES: Effect size: MVC: Maximum voluntary contraction; Nm:Newton meters; RM: Repetition maximum; SD: Standard deviation; SI: Strength index.

"Lift Big-Get Big": The Impact of Images of Hyper-Muscular Bodies and Training Information

Purpose: It has been suggested that the media influence beliefs regarding ideal body appearance and drive for muscularity whilst also offering recommendations for achieving this; most commonly heavy load free weight resistance training (RT). However, evidence for media effects are inconsistent in the literature. This study investigated this "lift big-get big" culture and effects of imagery on males' beliefs regarding RT. Method: An online survey was conducted with male participants (N = 110) randomized to different images (hyper-muscular/lean/control) and RT information ("lift big-get big"/"evidence based RT"/control). Results: Descriptive data suggested belief in necessity of heavy loads and free weights was pervasive. There was a small significant effect of condition for multivariate analysis of beliefs regarding RT. Univariate analyses showed significant effects of condition regarding the importance of free weights and heavy loads for strength, and free weights for hypertrophy. Small to moderate effects were found comparing "evidence-based RT" with a hyper-muscular physique to "lift big-get big" conditions with both hyper-muscular and lean physiques, the latter more likely to agree free weights and heavy loads are necessary for strength. A small effect was found comparing "lift big-get big" conditions with both hyper-muscular and lean physiques and the control condition, the former more likely to agree free weights are necessary for hypertrophy. Conclusions: Although hyper-muscular bodies alone did not influence RT beliefs, new information, i.e., "evidence-based RT" combined with a hyper-muscular physique had a small effect. The "lift big-get big" culture is perhaps pervasive enough that most conditions merely reinforced existing beliefs.

The Minimum Effective Training Dose Required for 1RM Strength in Powerlifters

The aim of this multi-experiment paper was to explore the concept of the minimum effective training dose (METD) required to increase 1-repetition-maximum (1RM) strength in powerlifting (PL) athletes. The METD refers to the least amount of training required to elicit meaningful increases in 1RM strength. A series of five studies utilising mixed methods, were conducted using PL athletes & coaches of all levels in an attempt to better understand the METD for 1RM strength. The studies of this multi-experiment paper are: an interview study with elite PL athletes and highly experienced PL coaches (n = 28), an interview and survey study with PL coaches and PL athletes of all levels (n = 137), two training intervention studies with intermediate-advanced PL athletes (n = 25) and a survey study with competitive PL athletes of different levels (n = 57). PL athletes looking to train with a METD approach can do so by performing ~3-6 working sets of 1-5 repetitions each week, with these sets spread across 1-3 sessions per week per powerlift, using loads above 80% 1RM at a Rate of Perceived Exertion (RPE) of 7.5-9.5 for 6-12 weeks and expect to gain strength. PL athletes who wish to further minimize their time spent training can perform autoregulated single repetition sets at an RPE of 9-9.5 though they should expect that strength gains will be less likely to be meaningful. However, the addition of 2-3 back-off sets at ~80% of the single repetitions load, may produce greater gains over 6 weeks while following a 2-3-1 squat-bench press-deadlift weekly training frequency. When utilizing accessory exercises in the context of METD, PL athletes typically utilize 1-3 accessory exercises per powerlift, at an RPE in the range of 7-9 and utilize a repetition range of ~6-10 repetitions.

Where next for the design, delivery and evaluation of community-based physical activity prescription? Emerging lessons from the United Kingdom

Despite widespread use, community-based physical activity prescription is controversial. Data limitations have resulted in a lack of clarity about what works, under what circumstances, and for whom, reflected in conservative policy recommendations. In this commentary we challenge a predominantly negative discourse, using contemporary research to highlight promising findings and 'lessons learnt' for design, delivery, and evaluation. In doing so, we argue for the importance of a more nuanced approach to future commissioning and evaluation. Contribution: • Amalgamating learning from multiple research teams to create recommendations for advancing physical activity prescription.

Can Earth's Mightiest Heroes Help Children Be Physically Active? Exploring the Immersive Qualities of Les Mills' and Marvel's "Move Like the Avengers" Video

There have been calls for more enjoyable Physical Activity (PA) interventions which focus on ensuring a positive affective response. This study explored how using a narrative, characters, and music in a video-led PA session might influence the sense of immersion and impact the affective response. One hundred and thirty-six participants (boys n = 65, girls n = 71) were recruited, 85% aged between 7 and 11 years old. Participants completed the "Move Like the Avengers" PA video created by Les Mills and Marvel, then complete a survey answering questions on their post activity affective responses, and the use of immersive elements. Positive average affective responses were found (valence mean score: 3.6 ± 2.2, arousal mean score: 5.1 ± 1.0). Analysis revealed the narrative with characters indirectly mediate the valence response through creating a sense of immersion (β_std = 0.122 [95%CI 0.013 to 0.231]; p = 0.012). Musical elements had both a direct (β_std = 0.449 [95%CI 0.264 to 0.634]; p < 0.001), and an indirect (β_std = 0.122 [95%CI 0.014 to 0.229]; p = 0.011) effect upon valence and a direct effect upon arousal (β_std = 0.244 [95%CI 0.006 to 0.482]; p = 0.021). These promising results provide justification for future research into children's immersive PA.

Resistance Training Performed to Failure or Not to Failure Results in Similar Total Volume, but With Different Fatigue and Discomfort Levels

ABSTRACT

Santos, WDNd, Vieira, CA, Bottaro, M, Nunes, VA, Ramirez-Campillo, R, Steele, J, Fisher, JP, and Gentil, P. Resistance training performed to failure or not to failure results in similar total volume, but with different fatigue and discomfort levels. J Strength Cond Res 35(5): 1372-1379, 2021-The purpose of this study was to compare the acute response to 4 sets of high velocity parallel squats performed to momentary failure (MF) or not to momentary failure (NF). Twelve women (24.93 ± 5.04 years) performed MF and NF protocols, in a randomized order with 2-3 interday rest. The protocol involved 4 sets of parallel squats executed at high velocity at 10RM load, with 2 minutes of rest interval between sets. During the NF protocol, the sets were interrupted when the subject lost more than 20% of mean propulsive velocity. The analysis involved the number of repetitions performed per set, total number of repetitions, movement velocity loss, power output loss, rating of perceived exertion (RPE), rating of perceived discomfort (RPD), and session rating of perceived exertion (sRPE). Compared with NF, MF resulted in a higher number of repetitions in the first set (11.58 ± 1.83 vs. 7.58 ± 1.72, p < 0.05), but a lower in the last set (3.58 ± 1.08 vs. 5.41 ± 1.08, p < 0.05). Total number of repetitions was similar between the protocols (MF 26.25 ± 3.47 vs. NF 24.5 ± 3.65, p > 0.05). In both protocols, there were significant decreases in maximum and mean movement velocity loss and power output loss, but higher decreases were observed in MF than NF (p < 0.05). Values for RPE, sRPE, and RPD were higher during MF than NF (p < 0.05). Controlling the movement velocity in NF protocol enabled performance of a similar total volume of repetitions with lower movement velocity and power output losses, RPE, sRPE, and RPD than during an MF protocol.

Non-local Muscle Fatigue Effects on Muscle Strength, Power, and Endurance in Healthy Individuals: A Systematic Review with Meta-analysis

BACKGROUND

The fatigue of a muscle or muscle group can produce global responses to a variety of systems (i.e., cardiovascular, endocrine, and others). There are also reported strength and endurance impairments of non-exercised muscles following the fatigue of another muscle; however, the literature is inconsistent.

OBJECTIVE

To examine whether non-local muscle fatigue (NLMF) occurs following the performance of a fatiguing bout of exercise of a different muscle(s).

DESIGN

Systematic review and meta-analysis.

SEARCH AND INCLUSION

A systematic literature search using a Boolean search strategy was conducted with PubMed, SPORTDiscus, Web of Science, and Google Scholar in April 2020, and was supplemented with additional 'snowballing' searches up to September 2020. To be included in our analysis, studies had to include at least one intentional performance measure (i.e., strength, endurance, or power), which if reduced could be considered evidence of muscle fatigue, and also had to include the implementation of a fatiguing protocol to a location (i.e., limb or limbs) that differed to those for which performance was measured. We excluded studies that measured only mechanistic variables such as electromyographic activity, or spinal/supraspinal excitability. After search and screening, 52 studies were eligible for inclusion including 57 groups of participants (median sample = 11) and a total of 303 participants.

RESULTS

The main multilevel meta-analysis model including all effects sizes (278 across 50 clusters [median = 4, range = 1 to 18 effects per cluster) revealed a trivial point estimate with high precision for the interval estimate [- 0.02 (95% CIs = - 0.14 to 0.09)], yet with substantial heterogeneity (Q₍₂₇₇₎ = 642.3, p < 0.01), I² = 67.4%). Subgroup and meta-regression analyses showed that NLMF effects were not moderated by study design (between vs. within-participant), homologous vs. heterologous effects, upper or lower body effects, participant training status, sex, age, the time of post-fatigue protocol measurement, or the severity of the fatigue protocol. However, there did appear to be an effect of type of outcome measure where both strength [0.11 (95% CIs = 0.01-0.21)] and power outcomes had trivial effects [- 0.01 (95% CIs = - 0.24 to 0.22)], whereas endurance outcomes showed moderate albeit imprecise effects [- 0.54 (95% CIs = - 0.95 to - 0.14)].

CONCLUSIONS

Overall, the findings do not support the existence of a general NLMF effect; however, when examining specific types of performance outcomes, there may be an effect specifically upon endurance-based outcomes (i.e., time to task failure). However, there are relatively fewer studies that have examined endurance effects or mechanisms explaining this possible effect, in addition to fewer studies including women or younger and older participants, and considering causal effects of prior training history through the use of longitudinal intervention study designs. Thus, it seems pertinent that future research on NLMF effects should be redirected towards these still relatively unexplored areas.

Structural development of cortical lobes during the first 6 months of life in infant macaques

This study mapped the developmental trajectories of cortical regions in comparison to overall brain growth in typically developing, socially-housed infant macaques. Volumetric changes of cortical brain regions were examined longitudinally between 2-24 weeks of age (equivalent to the first 2 years in humans) in 21 male rhesus macaques. Growth of the prefrontal, frontal, parietal, occipital, and temporal cortices (visual and auditory) was examined using MRI and age-specific infant macaque brain atlases developed by our group. Results indicate that cortical volumetric development follows a cubic growth curve, but maturational timelines and growth rates are region-specific. Total intracranial volume (ICV) increased significantly during the first 5 months of life, leveling off thereafter. Prefrontal and temporal visual cortices showed fast volume increases during the first 16 weeks, followed by a plateau, and significant growth again between 20-24 weeks. Volume of the frontal and temporal auditory cortices increased substantially between 2-24 weeks. The parietal cortex showed a significant volume increase during the first 4 months, whereas the volume of the occipital lobe increased between 2-12 weeks and plateaued thereafter. These developmental trajectories show similarities to cortical growth in human infants, providing foundational information necessary to build nonhuman primate (NHP) models of human neurodevelopmental disorders.

Comparison of Isolated Lumbar Extension Strength in Competitive and Noncompetitive Powerlifters, and Recreationally Trained Men

ABSTRACT

Androulakis-Korakakis, P, Gentil, P, Fisher, JP, and Steele, J. Comparison of isolated lumbar extension strength in competitive and noncompetitive powerlifters, and recreationally trained men. J Strength Cond Res 35(3): 652-658, 2021-Low-back strength has been shown to significantly impact performance in a plethora of sports. Aside from its effect on sport performance, low-back strength is strongly associated with low-back pain. A sport that heavily involves the lower-back musculature is powerlifting. This study looked to compare isolated lumbar extension (ILEX) strength in competitive and noncompetitive powerlifters, and recreationally trained men. Thirteen competitive powerlifters (CPL group; 31.9 ± 7.6 years; 173.4 ± 5.5 cm; 91.75 ± 18.7 kg), 10 noncompetitive powerlifters (NCPL group; 24 ± 3.5 years; 179 ± 4.8 cm; 92.39 ± 15.73 kg), and 36 recreationally trained men (RECT group; 24.9 ± 6.5 years; 178.5 ± 5.2 cm; 81.6 ± 10.0 kg) were tested for ILEX. Isolated lumbar extension strength was measured at every 12° throughout subject's full range of motion (ROM) and expressed as the following: "strength index (SI)" calculated as the area under a torque curve from multiple angle testing, average torque produced across each joint angle (AVG), and maximum torque produced at a single angle (MAX). Deadlift and squat strength were measured using 1 repetition maximum for the competitive and noncompetitive powerlifters. The following powerlifting characteristics were recorded for the competitive and noncompetitive powerlifters: primary deadlift stance, primary squat bar position, use of belt, use of performance-enhancing drugs, and use of exercises to target the lower-back musculature. Significant between-group effects were found for subject characteristics (age, stature, body mass, and ROM). However, analysis of covariance with subject characteristics as covariates found no significant between-group effects for SI (p = 0.824), AVG (p = 0.757), or MAX (p = 0.572). In conclusion, this study suggests that powerlifting training likely has little impact on conditioning of the lumbar extensors.

Physical activity and sedentary time in children and adolescents with asthma: A systematic review and meta-analysis

The influence of asthma on physical activity (PA) in youth remains equivocal. This review synthesizes the evidence regarding the influence of asthma on PA and sedentary time and evaluates the role of key moderators for this relationship. In accordance with PRISMA guidelines, six electronic databases and gray literature were searched. Primary studies in English were included if they reported device-assessed PA in youth with and without asthma. Random effects meta-analyses examined the effect of asthma on PA and, separately, sedentary time. Mixed-effect meta-regression analyses were conducted using age and sex as moderators, with sub-group comparisons for study quality and asthma diagnosis criteria. Overall, of 3944 citations retrieved, 2850 were screened after the removal of supplication and 2743 citations excluded. Of the 107 full-text publications reviewed, 16 were included in data extraction and analysis, with 15 and five studies included in the PA and sedentary time meta-analyses, respectively. The robust effect size estimate for the influence of asthma on PA and sedentary time was -0.04 [95% CI = -0.11, 0.03] and -0.09 [95% CI = -0.12, -0.06], indicating a non-significant and significant trivial effect, respectively. The effect of asthma on PA levels or sedentary time was not associated with age or sex. Youth with controlled asthma are equally physically (in)active as their healthy peers, with asthma associated with less sedentary time. However, methodological limitations and a paucity of clear methodological reporting temper these conclusions. More rigorous device-based assessments, with a particular focus on sedentary time, and more robust diagnoses of asthma, especially with regard to severity, are needed.

Efficacy of Whole-Body Electromyostimulation (WB-EMS) on Body Composition and Muscle Strength in Non-athletic Adults. A Systematic Review and Meta-Analysis

This systematic review and meta-analysis set out to determine the efficacy on whole-body electromyostimulation (WB-EMS) on body composition and strength parameters in non-athletic cohorts. A systematic review of the literature according to the PRISMA statement included (a) controlled trials, (b) WB-EMS trials with at least one exercise and one control group, (c) WB-EMS as primary physical intervention, (d) WB-EMS with at least six electrodes covering most muscle groups, (e) non-athletic cohorts. We searched eight electronic databases up to June 30, 2020, without language restrictions. Standardized mean differences (SMD) for muscle mass parameters, total body fat mass, maximum leg extension, and trunk extension strength were defined as outcome measures. In summary, 16 studies with 19 individual WB-EMS groups representing 897 participants were included. Studies vary considerably with respect to age, BMI, and physical conditions. Impulse protocols of the studies were roughly comparable, but training frequency (1-5 sessions/week) and intervention length (6-54 weeks) differed between the studies. SMD average was 1.23 (95%-CI: 0.71-1.76) for muscle mass, 0.98 (0.74-1.22) for maximum leg, and 1.08 (0.78-1.39) for maximum trunk extension strength changes (all p < 0.001). SMD for body fat changes (-0.40, [-0.98 to 0.17]), however, did not reach significance. I ² and Q-statistics revealed substantial heterogeneity of muscle and fat mass changes between the trials. However, rank and regression tests did not indicate positive evidence for small-study bias and funnel plot asymmetries. This work provided further evidence for significant, large-sized effects of WB-EMS on muscle mass and strength parameters, but not on body fat mass. Clinical Trial Registration: ClinicalTrials.gov, PROSPERO; ID: CRD42020183059.

"Just One More Rep!" - Ability to Predict Proximity to Task Failure in Resistance Trained Persons

In resistance training, the use of predicting proximity to momentary task failure (MF, i.e., maximum effort), and repetitions in reserve scales specifically, is a growing approach to monitoring and controlling effort. However, its validity is reliant upon accuracy in the ability to predict MF which may be affected by congruence of the perception of effort compared with the actual effort required. The present study examined participants with at least 1 year of resistance training experience predicting their proximity to MF in two different experiments using a deception design. Within each experiment participants performed four trials of knee extensions with single sets (i.e., bouts of repetitions) to their self-determined repetition maximum (sdRM; when they predicted they could not complete the next repetition if attempted and thus would reach MF if they did) and MF (i.e., where despite attempting to do so they could not complete the current repetition). For the first experiment (n = 14) participants used loads equal to 70% of a one repetition maximum (1RM; i.e., the heaviest load that could be lifted for a single repetition) performed in a separate baseline session. Aiming to minimize participants between day variability in repetition performances, in the second separate experiment (n = 24) they used loads equal to 70% of their daily isometric maximum voluntary contraction (MVC). Results suggested that participants typically under predicted the number of repetitions they could perform to MF with a meta-analytic estimate across experiments of 2.0 [95%CIs 0.0 to 4.0]. Participants with at least 1 year of resistance training experience are likely not adequately accurate at gauging effort in submaximal conditions. This suggests that perceptions of effort during resistance training task performance may not be congruent with the actual effort required. This has implications for controlling, programming, and manipulating the actual effort in resistance training and potentially on the magnitude of desired adaptations such as improvements in muscular hypertrophy and strength.

Influence of Adding Single-Joint Exercise to a Multijoint Resistance Training Program in Untrained Young Women

Barbalho, M, Gentil, P, Raiol, R, Fisher, J, Steele, J, and Coswig, V. Influence of adding single-joint exercise to a multijoint resistance training program in untrained young women. J Strength Cond Res 34(8): 2214-2219, 2020-The aim of the present study was to investigate the effects of adding single-joint (SJ) exercises to a multijoint (MJ) resistance training (RT) program on muscle strength and anthropometric measures of young women. Twenty untrained women were divided into a group that performed only MJ exercises or a group that performed both SJ and MJ exercises (MJ + SJ). Before and after 8 weeks of training, the participants were tested for 10 repetition maximum (10RM). Flexed arm circumference and triceps and biceps skinfold thickness were also measured. Both groups significantly decreased biceps (-3.60% for MJ and -3.55% for MJ + SJ) and triceps skinfold (-3.05% for MJ and -2.98% for MJ + SJ), with no significant difference between them. Flexed arm circumference significantly increased in both groups; however, increases in MJ + SJ (4.39%) were significantly greater than MJ (3.50%). Increases in 10RM load in elbow extension (28.2% for MJ and 28.0% for MJ + SJ), elbow flexion (29.8% for MJ and 28.7% for MJ + SJ), and knee extension (26.92% for MJ and 23.86% for MJ + SJ) were all significant and not different between groups. The results showed that adding SJ exercises to an MJ RT program resulted in no additional benefits in muscle performance, whilst differences in flexed arm circumference were small, but significant, in untrained women.

The relationship between isometric mid-thigh pull variables and athletic performance measures: empirical study of English professional soccer players and meta-analysis of extant literature

BACKGROUND

There is currently limited evidence available to support the use of the isometric mid-thigh pull (IMTP) within professional soccer. The aim of this study was to analyze the association between IMTP variables, with common markers of athletic performance capability.

METHODS

Eleven professional development soccer players (age: 20±2 years, stature: 1.82±0.10 m, mass: 76.4±12.8 kg) performed IMTP, 5 m and 10 m accelerations, maximal sprint speed (MSS), countermovement jump (CMJ), and the 505 change of direction test (COD).

RESULTS

Relative and absolute peak force (PF) and force at 50, 100, 150 and 200 ms values were measured during the IMTP. Relative F150, F200, PF displayed large to very large correlations with MSS (r=0.51, r=0.66, and r=0.76 respectively), while absolute PF also displayed a large correlation with MSS (r=0.57). Relative and absolute PF showed large correlations with CMJ height (r=0.54 and r=0.55 respectively). Relative F150 and F200 highlighted large correlations with COD ability (r=-0.68 and r=-0.60 respectively). Relative F200 and PF had a large negative correlation with 10 m acceleration (r=-0.55 and r=-0.53 respectively).

CONCLUSIONS

This study provides an important contribution to knowledge within the area of IMTP testing in professional soccer by evidencing the prominence of the isometric force generating capacity as an underpinning factor in relation to athletic capability.

One-year surveillance of body mass index and cardiorespiratory fitness in UK primary school children in North West England and the impact of school deprivation level

OBJECTIVES

Cardiorespiratory fitness (CRF) is independently associated with health and academic attainment in childhood and adolescence. Yet overweight/obesity remains the focus in public health policy. Surveillance of body mass index (BMI) and CRF considering school deprivation levels is limited. Therefore, we examined this in English primary schools.

METHODS

Participants (n=409) were students (9-10 years) from 13 schools. BMI and CRF (20 m shuttle run) were measured at three time points across the academic year and a fourth after summer recess.

RESULTS

BMI z-scores significantly decreased (p=0.015) from autumn (z=0.336 (95% CI 0.212 to 0.460)) to spring (z=0.252 (95% CI 0.132 to 0.371)), and then significantly increased (p=0.010) to summer (z=0.327 (95% CI 0.207 to 0.447)). CRF significantly increased (p<0.001) from autumn (z=0.091 (95% CI -0.014 to 0.196)) to spring (z=0.492 (95% CI 0.367 to 0.616)), no change (p=0.308) into summer (z=0.411 (95% CI 0.294 to 0.528)) and a significant decrease (p<0.001) into the following autumn term (z=0.125 (95% CI 0.021 to 0.230)). BMI was unaffected by deprivation; however, pupils from the most deprived areas saw significantly greater reductions in CRF compared with pupils from affluent areas. No time, or deprivation level, by sex interactions were found.

CONCLUSION

Significant reductions in children's CRF occurred over the summer recess and were greater among children from schools in the most deprived areas. This may help inform future research into interventions targeting physical activity of schoolchildren, particularly over the summer recess.

Defining clinical decision making in the provision of audio-visual outpatient care for acute upper limb trauma services: A review of practice

The Covid-19 pandemic has accelerated the widespread adoption of technology-enabled care in the NHS.¹ Moving into phase two of the response, the continuing use of audio-visual technology is expected, where appropriate, to be integral in the provision of safe, quality patient care.² A clinical need therefore exists to identify when care can be safely delivered remotely using audio-visual technology and when there is a need for in-person contact.  At Salisbury Foundation Trust (SFT), during phase one of the NHS response to Covid-19, the decision to treat upper limb trauma patients in-person or remotely was made using clinical screening criteria. For many patients, audio-visual appointments offered a practical, time efficient way of accessing their reconstructive team for assessment, advice and post-operative care. However, a subset of patients was identified by the team as requiring at least one in-person consultation to minimize perceived clinical risk and to optimize quality outcomes.  In order to understand more fully the challenges and successes of technology-enabled care to date, a national survey of practice across hand units in the UK was conducted. We present here some of our key findings and propose the need to develop nationally agreed screening criteria to determine how and when technology enabled outpatient care can be used in the management of acute upper limb trauma. The results of this survey forms part of a series of projects currently underway looking at the efficacy of audio-visual care in upper limb trauma, including a multicentre observational study.

Upskilling the surgical workforce for vascular access provision during the COVID-19 pandemic - The Salisbury experience

A vascular access device is defined as a catheter inserted into veins allowing fluids and medicines to be delivered intravenously¹. The need for such devices in acutely unwell patients has remained steady throughout the COVID-19 pandemic. We describe here our experience of up-skilling the resident plastic surgery and maxillofacial surgical registrars to provide a vascular access service to reduce the workload on our intensive care colleagues. We hope that our practice and an ‘all hands on deck’ approach to the utilisation of baseline skills within the existing workforce will inform other departments to help ease the burden on critical care departments as we progress through the next stages of the COVID-19 pandemic.

Evaluating the results of resistance training using ultrasound or flexed arm circumference: A case for keeping it simple?

BACKGROUND

The present study aimed to compare changes in muscle size when measured by ultrasound (US) muscle thickness (MT) and arm circumference (AC) using data from young men.

METHODS

The investigation involved data from three previous studies involving a total of 67 young men who performed resistance training (RT) for 10-12 weeks. Before and after the training period, elbow flexor MT was evaluated by US and AC was measured. We conducted two-stage individual patient data random-effects meta-analyses using both Frequentist and Bayesian hypothesis testing. One-sample analyses examined the absence or presence of a change in both MT and AC, and paired analyses examined whether these differed from one another or equivalent.

RESULTS

One-sample analysis supported that both AC (+4.9%; tp=0.0002; BF10=6,255,759,515) and MT (+3.9%; P<0.0001; BF10=7,958,241,773) suggested that change in muscle size had occurred. Frequentist paired comparisons suggested that the estimates of change between both AC and MT measures did not significantly differ (P=0.1092), but were not statistically equivalent. Bayesian paired comparisons, however, suggested that MT estimates where greater in magnitude than AC estimates for change in muscle size (BF10=16.39174).

CONCLUSION

Both MT and AC are able to detect RT-induced changes in muscle size of the upper arm, but that the magnitude of changes may differ. Thus, care should be taken when comparing or combining estimates using either approach.

RELEVANCE FOR PATIENTS

The use of AC might be considered as a practical and low-cost alternative to detect changes in muscle size.

Early Developmental Trajectories of Functional Connectivity Along the Visual Pathways in Rhesus Monkeys

Early social interactions shape the development of social behavior, although the critical periods or the underlying neurodevelopmental processes are not completely understood. Here, we studied the developmental changes in neural pathways underlying visual social engagement in the translational rhesus monkey model. Changes in functional connectivity (FC) along the ventral object and motion pathways and the dorsal attention/visuo-spatial pathways were studied longitudinally using resting-state functional MRI in infant rhesus monkeys, from birth through early weaning (3 months), given the socioemotional changes experienced during this period. Our results revealed that (1) maturation along the visual pathways proceeds in a caudo-rostral progression with primary visual areas (V1-V3) showing strong FC as early as 2 weeks of age, whereas higher-order visual and attentional areas (e.g., MT-AST, LIP-FEF) show weak FC; (2) functional changes were pathway-specific (e.g., robust FC increases detected in the most anterior aspect of the object pathway (TE-AMY), but FC remained weak in the other pathways (e.g., AST-AMY)); (3) FC matures similarly in both right and left hemispheres. Our findings suggest that visual pathways in infant macaques undergo selective remodeling during the first 3 months of life, likely regulated by early social interactions and supporting the transition to independence from the mother.