The Benefits of Strength Training on Musculoskeletal System Health: Practical Applications for Interdisciplinary Care

Muscle-to-Bone Ratio in NCAA Division I Collegiate Football Players by Position

ABSTRACT

Dengel, DR, Studee, HR, Juckett, WT, Bosch, TA, Carbuhn, AF, Stanforth, PR, and Evanoff, NG. Muscle-to-bone ratio in NCAA division I collegiate football players by position. J Strength Cond Res XX(X): 000-000, 2024-The purpose of this study was to compare the muscle-to-bone ratio (MBR) in National Collegiate Athletic Association Division I football players (collegiate football players [CFP]) to healthy, age-matched controls. In addition, we examined MBR in CFP by position. A total of 553 CFP and 261 controls had their total and regional lean mass (LM), fat mass (FM), and bone mineral content (BMC) determined by dual x-ray absorptiometry (DXA). College football players were categorized by positions defined as offensive linemen (OL), defensive linemen (DL), tight end, linebacker (LB), running back (RB), punter or kicker, quarterback (QB), defensive back (DB), and wide receiver (WR). There were significant differences between CFP and controls for total LM (80.1 ± 10.0 vs. 56.9 ± 7.8 kg), FM (22.2 ± 12.5 vs. 15.2 ± 7.1 kg), and BMC (4.3 ± 0.5 vs. 3.1 ± 0.5 kg). Although there were significant differences in body composition between CFP and controls, there was no significant differences in total MBR between CFP and controls (18.6 ± 1.4 vs. 18.8 ± 1.7). Regionally, CFP had significantly lower trunk MBR than controls (26.7 ± 2.7 vs. 28.7 ± 4.2), but no difference was seen in leg or arm MBR. Positional differences in CFP were noted as total MBR being significantly higher in DL (19.0 ± 1.4) than in DB (18.1 ± 1.3), WR (18.1 ± 1.3), and LB (18.2 ± 1.3). OL had a significantly higher total MBR (19.2 ± 1.3) than DB (18.1 ± 1.3), LB (18.2 ± 1.3), QB (18.1 ± 1.0), and WR (18.1 ± 1.3). In addition, RB had significantly higher total MBR (18.8 ± 1.3) than DB (18.1 ± 1.3) and WR (18.1 ± 1.3). This study may provide athletes and training staff with normative values when evaluating total and regional MBR with DXA.

Exploring the biomechanics and fatigue patterns of eccentric quasi-isometric muscle actions in the knee extensors and flexors

PURPOSE

Eccentric quasi-isometric (EQI) resistance training is emerging as a promising option in sports medicine and rehabilitation. Despite prior research on EQI contractions in quadriceps and biceps brachii, their use in hamstring injury contexts is underexplored. Therefore, our study examines and contrasts the biomechanics and fatigue effects of EQI training on knee extensors and flexors.

METHODS

Following familiarization, 16 healthy, active participants (9 men, 7 women; 23.5 ± 2.6 years, 72.1 ± 12.8 kg, 173.4 ± 10.7 cm) performed, in random order, four EQI contractions for knee extensions and flexions, respectively. EQI contractions were isotonically loaded to 70% of concentric (60°·s-1) maximal voluntary contraction. Rest between repetitions was set at three minutes, while four minutes separated each muscle group. Peak torque, mean torque, and optimal angle were evaluated pre- and post-bouts. Inter-repetition contraction time and angular velocity were also assessed.

RESULTS

Average torque was 160.9 ± 44.2 and 71.5 ± 23.2 Nm for the extensors and flexors. Peak and mean torque significantly decreased for both extensors (p < 0.001, d = 0.70-0.71) and flexors (p ≤ 0.022, d = 0.36) after EQI contractions, respectively. However, the optimal angle increased for extensors (p < 0.001, d = 1.00) but not flexors (p = 0.811, d = 0.06). During EQI contractions, knee flexors exhibited greater intra-repetition velocity than extensors (p = 0.002; η2 = 0.50). Decreases in inter-repetition time and range of motion were more consistent for the extensors.

CONCLUSIONS

Distinct responses exist when comparing EQI contractions of the knee extensors and flexors, particularly their effect on peak torque angles. These findings suggest knee flexors may require lower relative intensities to align more closely with extensor EQI contractions.

The Role of Musculoskeletal Training During Return to Performance Following Relative Energy Deficiency in Sport

BACKGROUND

Relative energy deficiency in sport (REDs) is a condition that is associated with negative health and performance outcomes in athletes. Insufficient energy intake relative to exercise energy expenditure, resulting in low energy availability, is the underlying cause, which triggers numerous adverse physiological consequences including several associated with musculoskeletal (MSK) health and neuromuscular performance.

PURPOSE

This commentary aims to (1) discuss the health and performance implications of REDs on the skeletal and neuromuscular systems and (2) examine the role that MSK training (ie, strength and plyometric training) during treatment and return to performance following REDs might have on health and performance in athletes, with practical guidelines provided.

CONCLUSIONS

REDs is associated with decreases in markers of bone health, lean body mass, maximal and explosive strength, and muscle work capacity. Restoration of optimal energy availability, mainly through an increase in energy intake, is the primary goal during the initial treatment of REDs with a return to performance managed by a multidisciplinary team of specialists. MSK training is an effective nonpharmacological component of treatment for REDs, which offers multiple long-term health and performance benefits, assuming the energy needs of athletes are met as part of their recovery. Supervised, prescribed, and gradually progressive MSK training should include a combination of resistance training and high-impact plyometric-based exercise to promote MSK adaptations, with an initial focus on achieving movement competency. Progressing MSK training exercises to higher intensities will have the greatest effects on bone health and strength performance in the long term.

Changes in Muscle Mass and Strength in Adolescents Following High-Intensity Functional Training with Bodyweight Resistance Exercises in Physical Education Lessons

(1) Background: The growing prevalence of obesity, diabetes, hypertension, and declining physical fitness among children and adolescents due to sedentary lifestyles has increased attention toward preventive intervention to tackle this issue. This study investigated the age-related effects of high-intensity functional training (HIFT), based on bodyweight resistance exercises conducted during physical education lessons, on muscle mass and strength improvement. (2) Methods: Adolescent males (n = 116) were allocated to four HIFT experimental groups (EGs) and four standard physical education program control groups (CGs) according to age (15, 16, 17, and 18 years [y]). The changes in muscle mass (absolute and relative to height [SMI]), hand-grip strength (HGS), sit-ups (SUs), and standing broad jump (SBJ) were analyzed using two-way analysis of variance (ANOVA) with Bonferroni tests. (3) Results: HIFT significantly increased muscle mass and scores in all strength tests (p < 0.01), while chronological age was significant for HGS (p < 0.01). Interactions between HIFT and chronological age categories were observed for HGS (p = 0.01) and SBJ (p < 0.03). Detailed post hoc tests revealed improvement in muscle mass across all chronological age categories for both approaches (p < 0.05). The 18y-EG group improved HGS over their control peers (p < 0.01), the EG groups significantly improved their SU results (p < 0.01), and SBJ improved in the 15y-EG and 18y-EG groups compared to their control (p < 0.01). (4) Conclusions: This research highlights the effectiveness of a school-based HIFT program in promoting muscle mass gains and enhancing muscle strength among adolescents. The findings offer valuable insights for implementing bodyweight exercises during physical education classes.

Muscular fitness profiles in relation to the response in body fat during school-based high-intensity intervention

BACKGROUND

We aimed to assess the equivalence of the muscular fitness (MF) between body fat percentage (BFP) responders (RsBFP) and non-responders (NRsBFP) to school-based high-intensity interval training (HIIT). Adolescents aged 16 (N.=73, 42.5% of males) were identified as RsBFP (N.=45) or NRsBFP (N.=28). MF was assessed based on hand strength (HS), abdominal muscle strength (ABS), and leg power (VJ).

METHODS

Profile analysis showed distinct patterns of MF changes in both response categories. Despite the presence of parallelism (Wilks' Λ=0.979, Pillai's V=0.212, P=0.473), a gradient of increasing changes (HS-ABS-VJ) was found in the RsBFP, while a gradient of decreasing changes was shown in the NRsBFP, and a significant level of inequality (F(1,71)=7.823, P=0.047, partial eta-squared [η2p] 0.041).

RESULTS

One-way analysis showed a significant and moderate effect on VJ (F(1,71)=7.080, P=0.010, η2P=0.091), a close to significant effect on ABS (F(1,71)=3.300, P=0.074, η2P=0.044) and lack of an effect on HS (F(1,71)=0.699, P=0.406, η2P=0.010). The test of equal means across the condition categories (separately for RsBFP and NRsBFP) indicated that there was no multivariate statistically significant within-group effect (F(2, 70)=0.517, P=0.599).

CONCLUSIONS

The findings may help teachers assess the potential and indirect changes in muscle performance after employing a body weight intervention (based on the HIIT program). A more targeted approach to treating adolescents with excessive BF, in parallel with improving MF, can be individually tailored.

Present but Ignored: Physical Condition and Health-Related Quality of Life in College-Aged Females with Generalized Joint Hypermobility

BACKGROUND

Generalized joint hypermobility (GJH) is prevalent among young adults, necessitating effective monitoring of musculoskeletal health, particularly among college-aged females. This study aimed to identify physical fitness and health-related quality of life (HR-QoL) characteristics associated with GJH.

METHODS

A total of 67 participants were assessed: 26 with GJH (mean age 20.06, SD 1.2 years), and 41 without (mean age 20.15, SD 2.2 years). Assessments included hypermobility, anthropometric data, foot posture, balance, flexibility, strength, and HR-QoL. We used the Mann-Whitney test for two independent samples, categorical variables were analyzed with Cramer's V test. The results indicated that participants with GJH exhibited inferior balance and back muscle static strength endurance but greater flexibility compared to those without GJH. Significant differences were observed in foot posture. However, handgrip strength, explosive strength, and abdominal muscle static strength endurance did not differ significantly between groups. No significant differences were observed in HR-QoL components between the two groups. In conclusion, there appears to be a link between GJH and increased flexibility, impaired balance, reduced back muscle static strength endurance, and altered posture of both feet.

A comprehensive study of the academic benefits and practical recommendations to include resistance training programs in institutional education

The connection between physical activity and cognitive function has become a focus of attention in educational research in recent years. Regular exercise has been shown to have significant positive effects on physical health, but it also appears to have a significant impact on cognitive function and academic performance. Of all the exercise modalities, resistance training has drawn interest for its ability to improve cerebral abilities in addition to physical well-being. However, there is limited available knowledge exploring the relationship between resistance training regimens and academic performance. This narrative review aims to investigate the underlying mechanisms linking resistance training to academic performance. Firstly, we will examine the biological mechanisms and psychosocial links that potentially connect resistance training to academic performance to find and describe the different mechanisms by which resistance training improves academic performance. In the next part of the work, we delve into the existing observational and intervention studies that have explored the relationship between resistance training and academic performance. Lastly, we provide practical recommendations for including resistance training in institutional education settings, emphasizing the need of dispelling myths and addressing barriers to increase participation as well as the relevance of considering key training variables and adaptation of protocols to developmental stages, always guided by a properly trained professional. Overall, the available evidence supports that resistance training provides potential benefits to the academic performance of youth students with many biological and psychosocial factors that explain this relationship. However, most of the studies are observational, and broader interventional studies are needed to understand and maximize the benefits of this type of physical exercise.

Effectiveness of specific scapular therapeutic exercises in patients with shoulder pain: a systematic review with meta-analysis

Background

Therapeutic exercise has been considered a useful tool to rehabilitate shoulder pain, namely through its influence on scapular dynamics. Accordingly, the effectiveness of scapular therapeutic exercise needs to be explored. The present study aims to evaluate the effectiveness of scapular therapeutic exercises in shoulder pain and to identify the most effective exercise type (focal or multijoint) and ways of delivering them (as dose and progression).

Methods

Search was conducted at EMBASE, Cochrane Library, MEDLINE via PubMed, Web of Science, PEDro (Physiotherapy Evidence Database), and trial registration databases. The meta-analysis considered randomized controlled/crossover trials that compared the effect of scapular exercises against other types of intervention in the shoulder pain, shoulder function, scapular motion, and/or muscular activity. The risk of bias was assessed through the PEDro scale.

Results

From the 8318 records identified, 8 (high to low risk of bias- scoring from 4 to 8 on the PEDro scale) were included. The overall data, before sensitivity analysis, indicated that the scapular therapeutic exercises are: a) more effective than comparators in improving shoulder function (standardized mean difference [SMD] = 0.52 [95% Cl: 0.05, 0.99], P = .03, I2 = 76%); and b) as effective as comparators in reducing shoulder pain (SMD = 0.32 [95% Cl: -0.09, 0.73], P = .13, I2 = 70%). Subgroup analysis revealed that scapular exercises are more effective in improving shoulder function when the program duration is equal to or higher than 6 weeks (SMD = 0.43 [95% Cl: 0.09, 0.76] P = .01, I2 = 21%) and/or when the maximum number of exercise repetitions per session is lower than 30 (SMD = 0.79 [95% Cl: 0.15, 1.42], P = .01, I2 = 77%). Only 1 study considered scapular motion as an outcome measure, revealing therapeutic exercise effectiveness to improve scapular range of motion.

Conclusions

Intervention programs involving scapular therapeutic exercises are effective in improving shoulder function, presenting benefits when performed for 6 or more weeks and/or when used up to a maximum of 30 repetitions per exercise, per session.

A Mixed Methods Feasibility Study of Machine-Based Resistance Training With Prefrail Older Adults in Residential Care: The Keeping Active in Residential Elderly Trial II

Physical activity is an effective, proactive intervention to reduce or reverse frailty and functional decline. However, uncertainty exists about the feasibility and impact of resistance training on multidimensional health in prefrail older adults in residential care. This mixed methods feasibility study assessed practicability with limited efficacy testing on health and functional outcomes. Eleven prefrail older adults participated in a 6-week progressive resistance training protocol three times per week. The intervention and measures were found to be appropriate and acceptable by those who completed the trial, with participants self-reporting improved well-being, mood, and function. Analysis identified several barriers to recruitment, including prior commitments, seasonal impact, and session timing, and offered potential solutions with further recommendations for program refinement prior to a definitive randomized controlled trial. These findings add to our understanding of prefrail older adults' preferences regarding participation in physical activity research and the perceived benefits of resistance training. This trial was registered with ClinicalTrials.gov: NCT03141879.

Evaluating the Effects of an Enhanced Strength Training Program in Remote Cardiological Rehabilitation: A Shift from Aerobic Dominance-A Pilot Randomized Controlled Trial

(1) Background: Cardiac rehabilitation often emphasizes aerobic capacity while overlooking the importance of muscle strength. This study evaluated the impact of an enhanced remote strength training program (RCR-ST) on cardiac rehabilitation. (2) Methods: In this randomized prospective study (RCT registration number SMC-9080-22), 50 patients starting cardiac rehabilitation were assessed for muscle strength, aerobic capacity, and self-reported outcomes at baseline and after 16 weeks. Participants were divided into two groups: the RCR-ST group received a targeted resistance training program via a mobile app and smartwatch, while the control group received standard care with general resistance training advice. (3) Results: The RCR-ST group demonstrated significant improvements in muscle endurance, notably in leg extension and chest press exercises, with increases of 92% compared to 25% and 92% compared to 13% in the control group, respectively. Functional assessments (5-STS and TUG tests) also showed marked improvements in agility, coordination, and balance. Both groups improved in cardiorespiratory fitness, similarly. The RCR-ST group reported enhanced physical health and showed increased engagement, as evidenced by more frequent use of the mobile app and longer participation in the rehabilitation program (p < 0.05). (4) Conclusions: Incorporating a focused strength training regimen in remote cardiac rehabilitation significantly improves muscle endurance and patient engagement. The RCR-ST program presents a promising approach for optimizing patient outcomes by addressing a crucial gap in traditional rehabilitation protocols that primarily focus on aerobic training.

Body image perception and dissatisfaction in resistance training practitioners: A critical review of the literature of Brazilian studies and assessment tools used

This study aimed to review the findings on body image (BI) dissatisfaction and muscle dysmorphia (MD) in Brazilian RT practitioners and the differences in the assessment tools used. A critical review of studies with searches in PubMed, Brazilian Virtual Health Library, SciELO, PsycInfo, and SPORTDiscus databases was conducted. A total of 23 studies were included. Nine tools were used to assess BI dissatisfaction or MD: three questionnaires and six visual scales. The overall mean BI dissatisfaction was 56.5% (59.2% in men vs 57.3% in women). The mean MD was 42.4% (45.1% in women vs 38.5% in men). BI dissatisfaction and MD are related to women seeking slimness and men wanting to increase muscle mass. In conclusion, the frequency of BI was high in both sexes, and MD, when identified, was higher in women. The scales and questionnaires used differ significantly in depth and scope for the same purpose.

Minimalist Training: Is Lower Dosage or Intensity Resistance Training Effective to Improve Physical Fitness? A Narrative Review

BACKGROUND

Findings from original research, systematic reviews, and meta-analyses have demonstrated the effectiveness of resistance training (RT) on markers of performance and health. However, the literature is inconsistent with regards to the dosage effects (frequency, intensity, time, type) of RT to maximize training-induced improvements. This is most likely due to moderating factors such as age, sex, and training status. Moreover, individuals with limited time to exercise or who lack motivation to perform RT are interested in the least amount of RT to improve physical fitness.

OBJECTIVES

The objective of this review was to investigate and identify lower than typically recommended RT dosages (i.e., shorter durations, lower volumes, and intensity activities) that can improve fitness components such as muscle strength and endurance for sedentary individuals or beginners not meeting the minimal recommendation of exercise.

METHODS

Due to the broad research question involving different RT types, cohorts, and outcome measures (i.e., high heterogeneity), a narrative review was selected instead of a systematic meta-analysis approach.

RESULTS

It seems that one weekly RT session is sufficient to induce strength gains in RT beginners with < 3 sets and loads below 50% of one-repetition maximum (1RM). With regards to the number of repetitions, the literature is controversial and some authors report that repetition to failure is key to achieve optimal adaptations, while other authors report similar adaptations with fewer repetitions. Additionally, higher intensity or heavier loads tend to provide superior results. With regards to the RT type, multi-joint exercises induce similar or even larger effects than single-joint exercises.

CONCLUSION

The least amount of RT that can be performed to improve physical fitness for beginners for at least the first 12 weeks is one weekly session at intensities below 50% 1RM, with < 3 sets per multi-joint exercise.

The reliability and suitability of strength assessments in frail and pre-frail older adults: recommendations for strength testing in older populations

BACKGROUND

Lifelong strength is fundamental to physical function, health, and quality of life. Reliable appropriate strength assessment measures for older adults play an important role in effective evaluation of baseline ability and exercise prescription to counter disease and disuse. This study aimed to investigate the within-session reliability of maximal isometric knee extension and flexion, hip abduction and adduction, and handgrip strength measures in frail and pre-frail older adults.

METHOD

The study was conducted at a residential care home in Birmingham, UK. All care home residents aged ≥ 65 years; pre-frail or frail according to the Fried Frailty phenotype criteria; able to speak and read English; not currently involved in any other clinical trial; without severe sensory impairments; and with a predicted life expectancy greater than the trial length were eligible. Maximal isometric lower limb testing was performed using specialised resistance training equipment and a portable measurement device, and grip strength was assessed using a portable dynamometer. All eligible participants attended a single testing session and performed three trials per measure. Peak force measures were obtained for analysis. Within-session reliability for each measure was calculated from repeated-measures analysis of variance, intraclass correlation coefficients (ICC), and coefficients of variation (CV) with 95% confidence intervals.

RESULTS

Eleven frail and eleven pre-frail older adults participated in the study. Within-session absolute and relative measures were found to be reliable with the highest overall repeatability indicated between trial 2 and trial 3 for knee extension, hip abduction, and handgrip (CV ≤ 4.65%, ICC ≥ 0.96) with variation evident across all measures, except knee extension, from trial 1 to 2.

CONCLUSIONS

Overall, maximal isometric strength in frail and pre-frail older adults with no previous testing experience can be measured with good to high reliability within their first testing session. An initial two familiarisation trials followed by two measurement trials is recommended to achieve the highest level of overall repeatability.

TRIAL REGISTRATION

The trial was registered with ClinicalTrials.gov: NCT03141879 on 05/05/2017.

"Restoring That Faith in My Shoulder": A Qualitative Investigation of How and Why Exercise Therapy Influenced the Clinical Outcomes of Individuals With Rotator Cuff-Related Shoulder Pain

OBJECTIVE

Rotator cuff-related shoulder pain (RCRSP) is the most common form of shoulder pain. Exercise therapy is a first-line recommended treatment for RCRSP. However, the causal mechanisms underpinning the benefits of exercise for RCRSP are not well understood. Moreover, how individuals with lived experience of RCRSP believe exercise helped or did not help them is unknown. This study aimed to gain insights into how individuals with RCRSP believe exercise influenced their shoulder pain and identify the clinical conditions that promoted or inhibited their beliefs.

METHODS

This qualitative study was underpinned by a critical realist approach to thematic analysis. Participants were recruited using hybrid purposive and convenience sampling techniques. Each participant attended an online semi-structured interview. The data were coded by 2 members of the research team (J.K.P. and N.C.) and verified by a third (B.S.). Recruitment continued until theoretical sufficiency was achieved. Participants reviewed and validated preliminary causal explanations.

RESULTS

Three causal explanations were consistently expressed by 11 participants to explain the benefits of exercise therapy: (1) shoulder strength; (2) changes to psychoemotional status; and (3) exercise has widespread health effects. However, the activation of these causal mechanisms depended on (1) the presence of a strong therapeutic relationship; (2) the provision of a structured and tailored exercise program; and (3) experiencing timely clinical progress.

CONCLUSION

Participants believed exercise improved their shoulder pain through associated health benefits, improved shoulder strength, and psychoemotional variables. Whether an exercise program was able to cause a clinical improvement for an individual with RCRSP was contingent on clinical contextual features. Thus, the clinical context that an exercise program is delivered within may be just as important as the exercise program itself.

IMPACT

Exercise is a recommended first-line intervention to manage RCRSP. The results of this study suggest that a positive experience and outcome with exercise for RCRSP is contingent on several clinical contextual features, such as a strong therapeutic relationship. The clinical context that an exercise program is prescribed and delivered within should be considered by clinicians.

Effects of digital-based interventions on muscular strength in adults: a systematic review, meta-analysis and meta-regression of randomized controlled trials with quality of evidence assessment

BACKGROUND

In the last three decades, both medical and sports science professionals have recognized the considerable potential of digital-based interventions (DBI) to enhance the health-related outcomes of their practitioners.

OBJECTIVES

This study aimed to investigate the effectiveness and potential moderators of DBI on measures of muscular strength.

METHODS

Six databases (PubMed/MEDLINE, Web of Science, SportDiscus, Embase, Cochrane Register of Controlled Trials and Google Scholar) were searched for eligible studies up to June 2022. The GRADE, PEDRO, and TIDieR checklists were used to assess the quality of evidence, methodology, and completeness of intervention descriptions, respectively.

RESULTS

A total of 56 studies were included in the meta-analysis (n = 2346), and participants were classified as healthy (n = 918), stroke survivors (n = 572), diagnosed with other neurological disorders (n = 683), and frail (n = 173). The DBI showed a small effect (standardized mean difference [SMD] = 0.28, 95% CI 0.21 to 0.31; p < 0.001) on strength, regardless of the type of intervention, control group, or tested body part. More specifically, while splitting the studies into different subgroups, a meta-analysis of 19 studies (n = 918) showed a small effect (SMD = 0.38, 95% CI 0.12 to 0.63; p = 0.003) on strength in the asymptomatic population. Similarly, small but positive effects of DBI were observed for stroke survivors (SMD = 0.34, 95% CI 0.13 to 0.56; p = 0.002), patients diagnosed with other neurological disorders (SMD = 0.17, 95% CI 0.03 to 0.32; p = 0.021), and the frail population (SMD = 0.25, 95% CI 0.0 to 0.5; p = 0.051). Sub-group analysis and meta-regression revealed that neither variable modified the effects of the DBI on measures of strength.

CONCLUSIONS

Overall, DBI may serve as an effective method to improve measures of strength in adults, regardless of their health status as well as the type of digital device, the presence of human-computer interaction, and the age of participants. In addition, the DBI was found to be more effective than traditional training or rehabilitation methods.KEY MESSAGESDigital-based intervention (DBI) is effective in improving measures of muscular strength in adults regardless of participants' health statusDBIs were equally effective for strength improvements in lower and upper limbsAlthough, DBIs were found to be effective in improving muscular strength, most studies did not follow strength training guidelines when prescribing the interventions.

The Impact of Regular Physical Exercise on Psychopathology, Cognition, and Quality of Life in Patients Diagnosed with Schizophrenia: A Scoping Review

The presence of less healthy lifestyle habits among individuals diagnosed with schizophrenia which can contribute to the escalation of physical disorders and exacerbation of psychological symptoms is well documented. The present scoping review aims to synthesize and evaluate the available evidence regarding the impact of regular physical exercise on psychopathology, cognition, and quality of life (QoL) in patients diagnosed with schizophrenia. A literature search was performed across Web of Science, SCOPUS, PubMed, and SPORTDiscus for randomized control trials published up to April 2022. Two independent reviewers applied the selection criteria and a third reviewer resolved discrepancies. A total of twelve studies were included, of which nine used endurance training and three used concurrent training (one of these additionally used resistance training). The results reveal benefits of various modalities of supervised regular exercise in the psychopathology of schizophrenia. Furthermore, regular endurance training seems to improve cognitive function in patients with schizophrenia and promote their QoL; however, results are inconclusive with respect to this last variable. The assessment of methodological quality in the reviewed articles indicates a high overall risk of bias, particularly in relation to deviations from intended interventions and the selection of reported results. Furthermore, an assessment of exercise reporting revealed that only 5 out of 19 items were fulfilled in more than 50% of the articles. Future research is needed to evaluate the effects of different training modalities and the optimal dose-response relationship in patients diagnosed with schizophrenia.

Does early post-operative exercise influence bone healing kinetics? Preclinical evaluation of non-critical sized femur defect healing

Physical exercise is a well-known modality for maintaining healthy locomotor mechanism. A detailed preclinical research on physical exercise effect on bone healing kinetics could help to improve the rehabilitation process after fracture treatment and bone remodeling. Our aim was to evaluate the effect of early post-operative exercise effect on bone microstructural changes in a rat model. Twenty Sprague Dawley male rats underwent bi-cortical 1.6 mm hole drilling in both femur diaphysis, after which (n = 10) underwent continuous treadmill training (TR) over two weeks, while the other group of rats (n = 10) was assigned to non-training (NT) control group. New bone formation labeling was performed by subcutaneous fluorochrome injections at day 5, 14 and 31. In vivo micro-computed tomography (μCT) scans were performed once a week during the 6-week post-operative period. Ten animals (five from each group) were euthanized at 3rd week while remaining animals were euthanized at 6th week. Femur samples were extracted and underwent ex vivo μCT and histological evaluation, while serum was used for evaluating alkaline phosphatase (ALP). μCT data demonstrated increased volume and surface of newly formed bone in defect area of TR group. Bone volume/Tissue volume (BV/TV) ratio and number of osteocytes showed an increase in TR group after 3-week period. Fluorochrome distances were increased between day 5 and 14 within the training group. Serum ALP level increased in both groups over 3- and 6-weeks. Post-operative exercise increases the bone healing kinetics and stimulates the new bone formation during and after the training protocol has ended.

Optimizing outdoor fitness equipment training for older adults: Benefits and future directions for healthy aging

Regular physical activity is vital for the health and disease prevention of older adults. Outdoor fitness equipment has gained popularity for natural exercise spaces among middle-aged and older individuals. This narrative review demonstrates that these programs have the potential to improve cardiovascular health, muscle strength, flexibility, balance, and reduce falls, while also enhancing quality of life, alleviating depression and anxiety, and boosting self-esteem. However, our understanding is hindered by limited rigorous experimental studies. Future directions include implementing standardized measurements, conducting long-term studies, and addressing equipment limitations to enable better adjustment of training intensity and promote correct postures on machines. New, more rigorous research is needed to comprehensively understand the psychophysiological and social effects on health. Additionally, suggested modifications could render the machines more effective and safer. The primary objective is to enhance this type of machinery to encourage its use in outdoor spaces, thus aiding adults and older individuals in achieving overall health and enjoying a healthy aging process.

A Muscle Load Feedback Application for Strength Training: A Proof-of-Concept Study

Muscle overload injuries in strength training might be prevented by providing personalized feedback about muscle load during a workout. In the present study, a new muscle load feedback application, which monitors and visualizes the loading of specific muscle groups, was developed in collaboration with the fitness company Gymstory. The aim of the present study was to examine the effectiveness of this feedback application in managing muscle load balance, muscle load level, and muscle soreness, and to evaluate how its actual use was experienced. Thirty participants were randomly distributed into 'control', 'partial feedback', and 'complete feedback' groups and monitored for eight workouts using the automatic exercise tracking system of Gymstory. The control group received no feedback, while the partial feedback group received a visualization of their estimated cumulative muscle load after each exercise, and the participants in the complete feedback group received this visualization together with suggestions for the next exercise to target muscle groups that had not been loaded yet. Generalized estimation equations (GEEs) were used to compare muscle load balance and soreness, and a one-way ANOVA was used to compare user experience scores between groups. The complete feedback group showed a significantly better muscle load balance (β = -18.9; 95% CI [-29.3, -8.6]), adhered better to the load suggestion provided by the application (significant interactions), and had higher user experience scores for Attractiveness (p = 0.036), Stimulation (p = 0.031), and Novelty (p = 0.019) than the control group. No significant group differences were found for muscle soreness. Based on these results, it was concluded that personal feedback about muscle load in the form of a muscle body map in combination with exercise suggestions can effectively guide strength training practitioners towards certain load levels and more balanced cumulative muscle loads. This application has potential to be applied in strength training practice as a training tool and may help in preventing muscle overload.

The Predictive Validity of Individualised Load-Velocity Relationships for Predicting 1RM: A Systematic Review and Individual Participant Data Meta-analysis

BACKGROUND

Load-velocity relationships are commonly used to estimate one-repetition maximums (1RMs). Proponents suggest these estimates can be obtained at high frequencies and assist with manipulating loads according to session-by-session fluctuations. Given their increasing popularity and development of associated technologies, a range of load-velocity approaches have been investigated.

OBJECTIVE

This systematic review and individual participant data (IPD) meta-analysis sought to quantify the predictive validity of individualised load-velocity relationships for the purposes of 1RM prediction.

METHODS

In September 2022, a search of MEDLINE, SPORTDiscus, Web of Science and Scopus was conducted for published research, with Google Scholar, CORE and British Ethos also searched for unpublished research. Studies were eligible if they were written in English, and directly compared a measured and predicted 1RM using load-velocity relationships in the squat, bench press, deadlift, clean or snatch. IPD were obtained through requests to primary authors and through digitisation of in-text plots (e.g. Bland-Altman plots). Risk of bias was assessed using the Prediction model Risk Of Bias ASsessment Tool (PROBAST) and the review conducted in accordance with PRISMA-IPD guidelines and an a priori protocol. Absolute and scaled standard error of the estimates (SEE/SEE%) were calculated for two-stage aggregate analyses, with bootstrapping performed for sampling variances. Estimates were pooled using three-level hierarchical models with robust 95% confidence intervals (CIs). One-stage analyses were conducted with random intercepts to account for systematic differences across studies and prediction residuals calculated in the absolute scale (kg) and as a percentage of the measured 1RM. Moderator analyses were conducted by including a priori defined categorical variables as fixed effects.

RESULTS

One hundred and thirty-seven models from 26 studies were included with each identified as having low, unclear or high risk of bias. Twenty studies comprising 434 participants provided sufficient data for meta-analyses, with raw data obtained for 8 (32%) studies. Two-stage analyses identified moderate predictive validity [SEE% 9.8, 95% CI 7.4% to 12.2%, with moderator analyses demonstrating limited differences based on the number of loads (β2Loads:>2Loads = 0.006, 95% CI - 1.6 to 1.6%) or the use of individual or group data to determine 1RM velocity thresholds (βGroup:Individualised =  - 0.4, 95% CI - 1.9 to 1.0%)]. One-stage analyses identified that predictions tended to be overestimations (4.5, 95% CI 1.5 to 7.4 kg), which expressed as a percentage of measured 1RM was equal to 3.7 (95% CI 0.5 to 6.9% 1RM). Moderator analyses were consistent with those conducted for two-stage analyses.

CONCLUSIONS

Load-velocity relationships tend to overestimate 1RMs irrespective of the modelling approach selected. On the basis of the findings from this review, practitioners should incorporate direct assessment of 1RM wherever possible. However, load-velocity relationships may still prove useful for general monitoring purposes (e.g. assessing trends across a training cycle), by providing high-frequency estimates of 1RM when direct assessment may not be logistically feasible. Given limited differences in predictions across popular load-velocity approaches, it is recommended that practitioners opting to incorporate this practice select the modelling approach that best suits their practical requirements.

REGISTRATION

https://osf.io/agpfm/ .

Males Have a Higher Energy Expenditure than Females during Squat Training

The main objective of this study was to determine the differences in energy expenditure (EE) according to sex during and after two different squat training protocols in a group of healthy young adults. Twenty-nine Sports Sciences students volunteered to participate in this study. They attended the laboratory on four different days and completed four sessions: two sessions with 3 sets of 12 repetitions at 75% of their one-repetition maximum (RM) and two sessions with 3 sets of 30 repetitions at 50% of their 1RM. Energy expenditure was evaluated using an indirect calorimeter. Males consistently demonstrated higher EE in all sessions and intensities. The linear regression model identified a significant association between sex, BMI, and total EE across all sessions and intensities. In conclusion, males exhibited higher EE in both protocols (50% and 75% of 1RM) throughout all sessions. Furthermore, sex and BMI were found to influence EE in healthy young adults. Therefore, coaches should consider sex when assessing EE, as the metabolic response differs between males and females.

The effectiveness of unilateral isokinetic resistance training on cross-education is independent of contraction velocity: a case of female dorsiflexors and plantar flexors

The large body of published literature has shown that the effects of strength training can transfer from trained to untrained homologous limb muscles after unilateral training. These effects on strength have been shown to be very specific to the type and speed of training contraction. The aim of this study was to investigate the effects of a 4-week unilateral slow and fast velocity isokinetic concentric training, to compare the effects, and thus investigate whether these effects are speed-specific. Forty-four healthy female students allocated to slow training, fast training, or control performed 12 isokinetic concentric-concentric plantar/dorsal flexors training sessions (3 × 4 weeks) using their nondominant leg. Participants in the two experimental groups showed statistically significant gains in strength in both the trained (ranging from 8 to 41%) and untrained leg (5-26%), thus showing cross-education on strength effects. The present study demonstrated that 4 weeks (12 training sessions) of unilateral isokinetic resistance training in the concentric mode improved the strength of contralateral, untrained homologous muscles to the same extent, regardless of the contraction velocity used in females. Furthermore, the amount of concentric overload (50% more than during 60°/s) did not appear to affect the increase in strength gains. Therefore, practitioners are encouraged to use both training speeds when strength gains in the contralateral leg are the primary goal. If the training time is limited, however, training with a higher contraction speed is recommended.

Influence of Strength Training Variables on Neuromuscular and Morphological Adaptations in Prepubertal Children: A Systematic Review

Strength training in prepubertal children is one of the topics that has aroused the most interest and controversy among training professionals in recent years. Therefore, the aim of the present study was to analyze the available scientific evidence on the influence of strength training variables on morphological and/or neuromuscular adaptations in healthy prepubertal populations with no previous experience in this type of training according to the descriptive sample characteristics. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis, 22 studies were selected after a systematic search and selection process using four electronic databases: Google Scholar, PubMed, Scopus, and SPORT Discus. Furthermore, the internal validity of the studies included was assessed using the modified PEDro scale. The sample consisted of 604 prepubertal children (age, 10.02 ± 0.75 years), of whom 473 were boys and 131 were girls, with 104 strength training programs recorded. Strength training resulted in a significant increase in jumping (n = 29) and sprinting (n = 13) abilities. Moreover, muscle strength was increased in 100% of the cases. Morphologically, strength training resulted in a decrease in body fat percentage (n = 19) and an increase in lean body mass (n = 17). With regard to gender, increases in general sport skills and basic physical abilities were significant in males but not in females. Thus, the results are more heterogeneous in girls due to the small number of studies carried out. Therefore, this research provides practical applications for coaches to design and implement more effective training programs to maximize adaptations, enhance physical performance, and reduce injury risk.

Hybrid-type, multicomponent interval training upregulates musculoskeletal fitness of adults with overweight and obesity in a volume-dependent manner: A 1-year dose-response randomised controlled trial

This study examined the dose-response effects of a 1-year hybrid-type, multicomponent interval training programme (DoIT) on various musculoskeletal fitness parameters in inactive overweight and obese adults in a gym setting. Ninety-seven middle-aged (44.8 ± 5.2 years) individuals with overweight/obesity (31.2 ± 5.7 kg/m²) (66% female) were randomly assigned to the following groups: (i) no-intervention control (CON, n = 29), (ii) DoIT performed once weekly (DoIT-1, n = 24), (iii) DoIT performed twice weekly (DoIT-2, n = 23) and (iv) DoIT performed thrice weekly (DoIT-3, n = 21). DoIT was a time-efficient, intermittent-based, multicomponent exercise protocol using progressive loaded fundamental movement patterns with prescribed work-to-rest intervals (1:3-2:1) in a circuit format (2-3 rounds). Muscular strength, muscular endurance, flexibility, passive range of motion (PRoM), static balance and functional movement screen (FMS®) were assessed at baseline, 6 and 12 months following intervention. At post-training, all exercise groups exhibited superior changes than CON in (i) muscular strength (+13%-38%, p < 0.001); (ii) muscular endurance (+42%-159%, p < 0.001); (iii) flexibility (+12%-42%, p < 0.001); (iv) PRoM (+6%-50%, p = 0.001-0.026); (v) static balance (+61%-163%, p < 0.001); and (vi) FMS (+18%-39%, p < 0.001). Although a single exercise session/week improved musculoskeletal fitness, changes demonstrated a step-wise improvement with two and three sessions/week suggesting a dose-dependent response. The response rate to training was 100% for all exercise groups. These findings suggest that a multicomponent exercise approach incorporating bodyweight drills and resistance-based alternative modes performed under real-world conditions may improve several musculoskeletal fitness indicators in a dose-dependent manner in inactive, middle-aged adults with overweight/obesity.Trial registration: ClinicalTrials.gov identifier: NCT03759951.

Resistance Training-Induced Acute Hypoalgesia in Women With Persistent Pain After Breast Cancer Treatment

ABSTRACT

Fogh Rasmussen, GH, Madeleine, P, Arroyo-Morales, M, Voigt, M, and Kristiansen, M. Resistance training-induced acute hypoalgesia in women with persistent pain after breast cancer treatment. J Strength Cond Res 37(3): e16-e24, 2023-The aim of this study was to determine whether a single bout of resistance training (RT) produces acute exercise-induced hypoalgesia (EIH) in breast cancer survivors (BCS) suffering from persistent pain ≥1.5 years after treatment. Twenty individuals with self-reported pain ≥3 on a 0-10 Numerical Rating Scale after treatment for breast cancer completed 3 experimental sessions, (a) familiarization; (b) 1 repetition maximum (1RM) normalization, and (c) training, consisting of 3 sets of 10 repetitions at 60% of 1 repetition maximum. Pressure pain thresholds (PPTs) were measured before and after training for the dorsal and ventral shoulder regions of the affected side. Movement-evoked pain (MEP) and rating of perceived exertion (RPE) were collected immediately after each set. A p -value less than 0.05 was considered statistically significant. The results demonstrated a significant increase in PPTs of the ventral shoulder region after a single bout of RT ( p ≤ 0.05), indicating a localized analgesic response for this area. By contrast, no change was detected in PPTs on the dorsal shoulder region. No significant differences were found in MEP between sessions despite a significant increase in load and RPE during 1RM assessment ( p ≤ 0.05), indicating that MEP was not affected by increase in absolute and relative intensity. In conclusion, a single bout of submaximal RT reduced PPTs for the ventral shoulder region of BCS with persistent pain after treatment and was well tolerated. Hence, RT may be a useful therapeutic tool for managing persistent pain after breast cancer treatment in clinical practice.

Sex differences in stretch-induced hypertrophy, maximal strength and flexibility gains

Introduction: If the aim is to increase maximal strength (MSt) and muscle mass, resistance training (RT) is primarily used to achieve these outcomes. However, research indicates that long-duration stretching sessions of up to 2 h per day can also provide sufficient stimuli to induce muscle growth. In RT literature, sex-related differences in adaptations are widely discussed, however, there is a lack of evidence addressing the sex-related effects on MSt and muscle thickness (MTh) of longer duration stretch training. Therefore, this study aimed to investigate the effects of 6 weeks of daily (1 h) unilateral static stretch training of the plantar flexors using a calf-muscle stretching device. Methods: Fifty-five healthy (m = 28, f = 27), active participants joined the study. MSt and range of motion (ROM) were measured with extended and flexed knee joint, and MTh was investigated in the medial and lateral heads of the gastrocnemius. Results: Statistically significant increases in MSt of 6%-15% (p < .001-.049, d = 0.45-1.09), ROM of 6%-21% (p < .001-.037, d = 0.47-1.38) and MTh of 4%-14% (p < .001-.005, d = 0.46-0.72) from pre-to post-test were observed, considering both sexes and both legs. Furthermore, there was a significant higher increase in MSt, MTh and ROM in male participants. In both groups, participants showed more pronounced adaptations in MSt and ROM with an extended knee joint as well as MTh in the medial head of the gastrocnemius (p < .001-.047). Results for relative MSt increases showed a similar result (p < .001-.036, d = 0.48-1.03). Discussion: Results are in accordance with previous studies pointing out significant increases of MSt, MTh and ROM due to long duration static stretch training. Both sexes showed significant increases in listed parameters however, male participants showed superior increases.

Effects of Concurrent Strength and Endurance Training on Measures of Physical Fitness in Healthy Middle-Aged and Older Adults: A Systematic Review with Meta-Analysis

BACKGROUND

There is evidence that in older adults the combination of strength training (ST) and endurance training (ET) (i.e., concurrent training [CT]) has similar effects on measures of muscle strength and cardiorespiratory endurance (CRE) compared with single-mode ST or ET, respectively. Therefore, CT seems to be an effective method to target broad aspects of physical fitness in older adults.

OBJECTIVES

The aim was to examine the effects of CT on measures of physical fitness (i.e., muscle strength, power, balance and CRE) in healthy middle-aged and older adults aged between 50 and 73 years. We also aimed to identify key moderating variables to guide training prescription.

STUDY DESIGN

We conducted a systematic review with meta-analysis of randomized controlled trials.

DATA SOURCES

The electronic databases PubMed, Web of Science Core Collection, MEDLINE and Google Scholar were systematically searched until February 2022.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

We included randomized controlled trials that examined the effects of CT versus passive controls on measures of physical fitness in healthy middle-aged and older adults aged between 50 and 73 years.

RESULTS

Fifteen studies were eligible, including a total of 566 participants. CT induced moderate positive effects on muscle strength (standardized mean difference [SMD] = 0.74) and power (SMD = 0.50), with a small effect on CRE (SMD = 0.48). However, no significant effects were detected for balance (p > 0.05). Older adults > 65 years (SMD = 1.04) and females (SMD = 1.05) displayed larger improvements in muscle strength compared with adults ≤ 65 years old (SMD = 0.60) and males (SMD = 0.38), respectively. For CRE, moderate positive effects (SMD = 0.52) were reported in those ≤ 65 years old only, with relatively larger gains in females (SMD = 0.55) compared with males (SMD = 0.45). However, no significant differences between all subgroups were detected. Independent single training factor analysis indicated larger positive effects of 12 weeks (SMD = 0.87 and 0.88) compared with 21 weeks (SMD = 0.47 and 0.29) of CT on muscle strength and power, respectively, while for CRE, 21 weeks of CT resulted in larger gains (SMD = 0.62) than 12 weeks (SMD = 0.40). For CT frequency, three sessions per week produced larger beneficial effects (SMD = 0.91) on muscle strength compared with four sessions (SMD = 0.55), whereas for CRE, moderate positive effects were only noted after four sessions per week (SMD = 0.58). A session duration of > 30-60 min generated larger improvements in muscle strength (SMD = 0.99) and power (SMD = 0.88) compared with > 60-90 min (SMD = 0.40 and 0.29, respectively). However, for CRE, longer session durations (i.e., > 60-90 min) seem to be more effective (SMD = 0.61) than shorter ones (i.e., > 30-60 min) (SMD = 0.34). ET at moderate-to-near maximal intensities produced moderate (SMD = 0.64) and small positive effects (SMD = 0.49) on muscle strength and CRE, respectively, with no effects at low intensity ET (p > 0.05). Finally, intra-session ST before ET produced larger gains in muscle strength (SMD = 1.00) compared with separate sessions (SMD = 0.55), whereas ET and ST carried out separately induced larger improvements in CRE (SMD = 0.58) compared with intra-session ET before ST (SMD = 0.49).

CONCLUSIONS

CT is an effective method to improve measures of physical fitness (i.e., muscle strength, power, and CRE) in healthy middle-aged and older adults aged between 50 and 73 years, regardless of sex. Results of independent single training factor analysis indicated that the largest effects on muscle strength were observed after 12 weeks of training, > 30-60 min per session, three sessions per week, higher ET intensities and when ST preceded ET within the same session. For CRE, the largest effects were noted after 21 weeks of training, four sessions per week, > 60-90 min per session, higher ET intensities and when ET and ST sessions were performed separately. Regarding muscle power, the largest effects were observed after 12 weeks of training and > 30-60 min per session.

Resistance training for postmenopausal women: systematic review and meta-analysis

IMPORTANCE

Numerous studies have been published assessing the effects of resistance muscle training to mitigate menopausal symptoms, given the endocrine muscle function and its metabolic regulation. Therefore, mapping and synthesizing high-quality studies are necessary to help clinical decisions.

OBJECTIVE

The aim of this study was to assess the effects (benefits and harms) of resistance muscle training for postmenopausal women.

EVIDENCE REVIEW

Electronic searches were conducted in MEDLINE (via PubMed), EMBASE, CENTRAL, PEDro, LILACS, and SPORTDiscus up to December 2021. Two independent reviewers selected the retrieved references and extracted relevant data from included studies. The methodological quality (risk of bias) using the Cochrane Risk of Bias table and the certainty of the evidence (GRADE approach) were assessed.

FINDINGS

Twelve randomized clinical trials (n = 452) with unclear to high risk of bias were identified. Compared with no exercise, resistance training (up to 16 weeks) seems to promote an improvement in functional capacity (mean difference [MD], 2.90 points; 95% CI, 0.60-5.20) and bone mineral density (MD, 0.10; 95% CI, 0.10-0.10) and a reduction in the hot flash frequency (13/29 vs 1/29; risk ratio, 13.0; 95% CI, 1.82-93.01) and fat mass (MD, -3.15; 95% CI, -6.68 to 0.38), and no differences were observed between groups regarding abdominal circumference and body mass index. When compared with aerobic exercises, resistance training may result in a reduction of hot flash frequency (7/18 vs 14/18; risk ratio, 0.50; 95% CI, 0.27-0.94) and fat mass (MD, -7.80; 95% CI, -14.02 to -1.58) and no difference in the quality of life and body mass index. Regarding safety, no serious adverse events were reported. Based on the GRADE approach, the certainty of this evidence was graded as very low to low, leading to imprecisely estimated effects.

CONCLUSIONS AND RELEVANCE

Resistance muscle training seems to improve postmenopausal symptoms and functional capacity. Given the low to very low certainty of the evidence, further randomized clinical trials with higher methodological quality and better reports are still needed. As an implication for clinical practice, health professionals should consider individualized aspects such as the previous history of exercise practice, physical capacity, and adaptation period.

Effectiveness of Resistance Exercise on Inflammatory Biomarkers in Patients with Type 2 Diabetes Mellitus: A Systematic Review with Meta-Analysis

BACKGROUND

Type 2 diabetes mellitus (T2DM) is related to increased inflammatory processes. The effects of resistance exercise on inflammatory biomarkers in T2DM are controversial. Our purpose was to determine the effectiveness of resistance exercise on inflammatory biomarkers in patients diagnosed with T2DM.

METHODS

We searched four databases until September 2021. We included randomized clinical trials (RCTs) of the effects of resistance exercise on inflammatory biomarkers (C-reactive protein [CRP], tumor necrosis factor alpha, interleukin-6, and interleukin-10) in patients with T2DM. A random effects meta-analysis was conducted to determine the standardized mean difference (SMD) and the raw mean difference (MD) for CRP.

RESULTS

Thirteen RCTs were included in the review, and 11 in the meta-analysis for CRP. Lower CRP levels were observed when resistance exercise was compared with the control groups (SMD=-0.20; 95% confidence interval [CI], -0.37 to -0.02). When conducting the MD meta-analysis, resistance exercise showed a significant decrease in CRP of -0.59 mg/dL (95% CI, -0.88 to -0.30); otherwise, in the control groups, the CRP values increased 0.19 mg/dL (95% CI, 0.17 to 0.21).

CONCLUSION

Evidence supports resistance exercise as an effective strategy to manage systemic inflammation by decreasing CRP levels in patients with T2DM. The evidence is still inconclusive for other inflammatory biomarkers.

Potential causal association between leisure sedentary behaviors, physical activity and musculoskeletal health: A Mendelian randomization study

BACKGROUND

Increasing evidence shows that leisure sedentary behaviors (LSB) and physical activity (PA) are associated with various musculoskeletal disorders. However, the causality between LSB/PA and musculoskeletal health remained unknown. In this study, we aimed to evaluate the causal relationships between LSB/PA and lower back pain (LBP), intervertebral disc disorder (IVDD), rheumatoid arthritis (RA), and bone mineral density (BMD) by using a two-sample Mendelian randomization method.

METHODS

The exposure data were obtained from large-scale genome-wide association studies (GWAS), including the PA dataset (self-reported PA, n  =  377,234; accelerometer-assessed PA, n  = 91,084) and LSB dataset (n  =  422,218). The outcome data were derived from the FinnGen LBP dataset (n  =  248,528), FinnGen IVDD dataset (n  =  256,896), BMD GWAS dataset (n  =  56,284), and RA GWAS dataset (n  =  58,284). The causal relationships were estimated with inverse variance weighted (IVW), MR-Egger, and weighted median methods. Sensitivity analyses were performed with Cochran's Q test, MR-Egger intercept test, and leave-one-out analysis to estimate the robustness of our findings.

RESULTS

Genetically predicted leisure television watching increased the risk of LBP (OR = 1.68, 95% CI 1.41 to 2.01; P = 8.23×10-9) and IVDD (OR  =  1.62, 95% CI 1.37 to 1.91; P  =  2.13 × 10-8). In addition, this study revealed a potential causal relationship between computer use and a reduced risk of IVDD (OR  = 0.60, 95% CI 0.42 to 0.86; P  =  0.005) and RA (OR  = 0.28, 95% CI 0.13 to 0.60; P  =  0.001).

CONCLUSIONS

Our results suggest that leisure television watching is a risk factor for LBP and IVDD, whereas leisure computer use may act as a protective factor against IVDD and RA. These findings emphasized the importance of distinguishing between different sedentary behaviors in musculoskeletal disease studies.

Velocity Loss Is Not an Accurate Predictor of the Percentage of Completed Repetitions During the Prone Bench Pull Exercise

ABSTRACT

Pérez-Castilla, A, Miras-Moreno, S, Janicijevic, D, and García-Ramos, A. Velocity loss is not an accurate predictor of the percentage of completed repetitions during the prone bench pull exercise. J Strength Cond Res XX(X): 000-000, 2022-The primary aim of this study was to explore the goodness of fit and accuracy of both general and individual relationships between the magnitude of velocity loss (%VL) and the percentage of performed repetitions with respect to the maximal number of repetitions that can be completed to failure (%Rep) during the Smith machine prone bench pull exercise. Fifteen male sports science students completed a preliminary session to determine the bench pull one-repetition maximum (1RM) and 2 identical experimental sessions separated by 48-72 hours. In each experimental session, subjects randomly performed single sets of repetitions to failure separated by 10 minutes against the 60% 1RM, 70% 1RM, and 80% 1RM during the Smith machine bench pull exercise. Individual %Rep-%VL relationships presented a greater goodness of fit than general %Rep-%VL relationships at the 60% 1RM (R2 = 0.85-0.97 vs. 0.79-0.85), 70% 1RM (R2 = 0.84-0.99 vs. 0.77-0.84), and 80% 1RM (R2 = 0.84-1.00 vs. 0.74-0.80). However, the accuracy (absolute errors) in estimating the %Rep during the second testing session based on the %Rep-%VL equations obtained in the first testing session did not differ between the individual and general %Rep-%VL equations in 8 of 9 comparisons (p ≥ 0.102). The absolute errors between the actual and predicted %REP were unacceptable (>10%) in 11 of 18 comparisons, and acceptable (5-10%) in 7 of 18 comparisons. These results highlight that the %Rep cannot be estimated with high degree of accuracy from VL recordings during the Smith machine bench pull exercise, regardless of whether individual or general Rep-%VL relationships are considered.

Older adults who resistance train improve physical function and adopt long-term exercise habits despite COVID-19 restrictions

Exercise interventions targeting older adults often focus on acute changes, but lasting improvements require the adoption of long-term, independent exercise habits. This study aimed to assess the influence of eight-weeks of resistance training (SSSH) on clinically relevant fall-risk indicators in older adults and to evaluate if SSSH participation altered independent exercise engagement 12 months later. Sixty adults aged 50 yrs+ were randomised into SSSH, Walk, or Control groups and completed questionnaires and muscle strength and flexibility tests pre/post 8 weeks. SSSH and Walk met 2x/wk for 60 min. Twelve months later 24 participants also completed a follow-up survey amid COVID-19 restrictions. Eight-week group changes were analysed using one-way ANOVA with Bonferroni post hoc analyses, and survey responses were compared using paired t-tests with a Bonferroni correction. SSSH demonstrated greater absolute changes over 8 weeks in sleep quality, activity engagement, 30-second-sit-to-stand and upper-body flexibility than Walk or Controls (p < 0.05). Twelve months later, SSSH participants reported significantly increasing independent resistance (+68), aerobic (+125) and flexibility (+26) training minutes per week (all p < 0.01). In conclusion, SSSH reduced fall risk in 8 weeks and sparked older adults to begin and sustain positive exercise habits 12 months later, despite COVID-19 restrictions.

Frozen shoulder

Frozen shoulder is a common debilitating disorder characterized by shoulder pain and progressive loss of shoulder movement. Frozen shoulder is frequently associated with other systemic conditions or occurs following periods of immobilization, and has a protracted clinical course, which can be frustrating for patients as well as health-care professionals. Frozen shoulder is characterized by fibroproliferative tissue fibrosis, whereby fibroblasts, producing predominantly type I and type III collagen, transform into myofibroblasts (a smooth muscle phenotype), which is accompanied by inflammation, neoangiogenesis and neoinnervation, resulting in shoulder capsular fibrotic contractures and the associated clinical stiffness. Diagnosis is heavily based on physical examination and can be difficult depending on the stage of disease or if concomitant shoulder pathology is present. Management consists of physiotherapy, therapeutic modalities such as steroid injections, anti-inflammatory medications, hydrodilation and surgical interventions; however, their effectiveness remains unclear. Facilitating translational science should aid in development of novel therapies to improve outcomes among individuals with this debilitating condition.

Effects of physical training on physical and functional fitness, physical activity level, endothelial function, hemodynamic variables, bone metabolism, and quality of life of post-bariatric patients: study protocol for a randomized controlled trial

BACKGROUND

Evidence of the benefits induced from resistance exercise on health markers of post-bariatric patients is limited. The study will investigate the effects of a resistance training (RT) program on muscle mass and strength, bone metabolism biomarkers, bone mineral density (BMD), bone microarchitecture, and endothelial function of patients subjected to Roux-en-Y gastric bypass.

METHODS/DESIGN

This randomized controlled trial will include 60 post-bariatric patients, physically inactive, aging 18 to 50 years, with a post-surgery period ≥ 12 months. They will be randomly assigned into two groups: (i) the non-exercised control group, which will receive the standard clinical follow-up, or (ii) the intervention group which will consist of RT (60 min/session; 3 times/week, for 6 months). The primary outcomes will include muscle mass and strength, bone metabolism biomarkers, BMD, and bone microarchitecture. The secondary outcomes will be anthropometry, hemodynamic measurements, cardiovascular risk factors, health-related quality of life (QoL), and endothelial function. Outcomes will be assessed by blood biomarkers of bone formation and reabsorption, dual X-ray absorptiometry, repetition maximum and handgrip strength tests, high-resolution peripheral quantitative computed tomography, 36-Item Short-Form Health Survey, venous occlusion plethysmography, and nailfold videocapillaroscopy.

DISCUSSION

It is expected that there are greater benefits from the RT program, possibly improving muscle mass and strength, bone metabolism, density and microarchitecture, QoL, and cardiovascular risk.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04193397. Registered on 7 December 2019.

Dose-response association of aerobic and muscle-strengthening physical activity with mortality: a national cohort study of 416 420 US adults

OBJECTIVES

To investigate the dose-response association of aerobic physical activity (PA) and muscle-strengthening exercise (MSE) with all-cause mortality.

METHODS

National Health Interview Survey data (1997-2014) were linked to the National Death Index through 2015, which produced a cohort of 416 420 US adults. Cox proportional-hazard models were used to estimate HRs and 95% CIs for the associations of moderate aerobic PA (MPA), vigorous aerobic PA (VPA) and MSE with mortality risk. Models controlled for age, sex, race-ethnicity, income, education, marital status, survey year, smoking status, body mass index and chronic conditions.

RESULTS

Relative to those who engaged in no aerobic PA, substantial mortality risk reduction was associated with 1 hour/week of aerobic PA (HR: 0.85, 95% CI: 0.83 to 0.86) and levelled off at 3 hours/week of aerobic PA (0.73, 0.71 to 0.75). Similar results were observed for men and women and for individuals younger and older than 60 years. MSE conferred additional mortality risk reduction at 1 time/week (0.89, 0.81 to 0.97) and appeared no longer beneficial at 7 times/week (0.99, 0.94 to 1.04).

CONCLUSION

The minimum effective dose of aerobic PA for significant mortality risk reduction was 1 hour/week of MPA or VPA, with additional mortality risk reduction observed up to 3 hours/week. For older adults, only small decreases in mortality risk were observed beyond this duration. Completing MSE in combination with aerobic PA conferred additional mortality risk reduction, with a minimum effective dose of 1-2 times/week.

Can strength training modify voluntary activation, contractile properties and spasticity in Multiple Sclerosis?: a randomized controlled trial

BACKGROUND

A randomized controlled trial was conducted to analyze the effects of 10 weeks of strength training (ST) on voluntary activation, muscle activity, muscle contractile properties, and spasticity in people with MS.

METHODS

30 participants were randomized to either an experimental [EG](n=18) or a control [CG](n=12) group. The EG carried out 10-weeks of ST, where the concentric phase at maximum voluntary velocity. Muscle activity of the vastus lateralis (surface electromyography (sEMG) during the first 200 ms of contraction), maximal neural drive (peak sEMG), voluntary activation (central activation ratio), and muscle contractile function (via electrical stimulation) of the knee extensor muscles, as well as spasticity, were measured pre- and post-intervention.

RESULTS

The EG showed a significant improvement with differences between groups in muscle activity in EMG_0-200 (p=0.031;ES=-0.8) and maximal neural drive (p=0.038;ES=-0.8), as well as improvement in the ST group with a trend towards significance in EMG_0-100 (p=0.068;ES=-0.6). CAR increased after intervention in ST group (p=0.010;ES=-0.4). Spasticity also improved in the ST group, with differences between group after intervention, in first swing excursion (right leg: p=0.006;ES=-1.4, left leg: p=0.031;ES=-1.2), number of oscillations (right leg: p=0.001;ES=-0.4, left leg: p=0.031;ES=-0.4) and duration of oscillations (left leg: p=0.002; ES=-0.6). Contractile properties remain unchanged in both ST group and control group.

CONCLUSIONS

10 weeks of ST improves muscle activity during the first 200 ms of contraction, maximal neural conduction, and spasticity in people with MS. However, ST does not produce adaptations in muscle contractile properties in people with MS.

Effects of self-selected versus motivational music on lower limb muscle strength and affective state in middle-aged adults

Background

Strength training plays a crucial role in promoting healthy ageing and music might affect how individuals perform and perceive strength exercises. This study aimed to investigate the effects of self-selected music (SSM) on muscle strength and affective states during maximal isometric contractions on a customized leg extension.

Methods

Twenty-six healthy middle-aged males (50.8 ± 8.4 years) performed maximal and endurance isometric strength tests under three different conditions: SSM, motivational music (MM), and control condition (CC). Peak force and Rate of Force Development (RFD) were assessed during the maximal isometric strength test. The isometric endurance test evaluated the mean force and a fatigue index. Moreover, Felt Arousal Scale (FAS) was administered before the strength protocol, whereas the Rate of Perceived Exertion (RPE) and Feeling Scale (FS) at the end of it.

Results

Mean force was significantly higher in the SSM (507.3 ± 132.2 N) than MM (476.3 ± 122.4 N, p < 0.01) and CC (484.6 ± 119.2 N, p = 0.03). FAS was significantly higher in the SSM (4.0 [1.3] than MM (3.0 [2.3], p < 0.01) and CC (3.0 [1.3], p < 0.01) conditions. FS was significantly higher in the SSM (4.0 [2.0] than MM (3.0 [1.3], p < 0.01) and CC (3.0 [1.3], p < 0.01) conditions. No significant differences were found for peak force, RFD, fatigue index, and RPE.

Conclusions

Listening to SSM seems to influence isometric endurance strength performance in middle-aged adults positively. Moreover, listening to SSM might improve individuals' affective states without affecting the level of perceived exertion.

Selecting Resistance Training Exercises for Novices: A Delphi Study with Expert Consensus

Resistance training (RT) is a form of exercise that provides numerous health benefits. One barrier to participation may be the technical demands associated with some exercises. While recommendations for RT, including the number of repetitions, sets, rest, and training loads are established, recommendations for exercise selection have not been addressed. We used a Delphi-type method in three iterative surveys. In the first survey, 17 experts rated the technical complexity of 77 different strength training exercises as having low, moderate, or high technical demands. A second survey was generated based on the first, such that exercises receiving a majority high complexity vote were removed. In the second survey, experts rated the remaining exercises as either appropriate or too advanced for a novice. Exercises were deemed appropriate if 70% agreement was reached. Lastly, experts rated exercises as being appropriate for adults over the age of 60. Experts agreed that 41 different exercises were appropriate for novices and that 32 of the exercises were appropriate for novice adults over the age of 60. Our findings provide recommendations for program design to compliment already established recommendations for RT of repetitions, sets, rest periods, and training loads.

Resistance Training Variables for Optimization of Muscle Hypertrophy: An Umbrella Review

This umbrella review aimed to analyze the different variables of resistance training and their effect on hypertrophy, and to provide practical recommendations for the prescription of resistance training programs to maximize hypertrophy responses. A systematic research was conducted through of PubMed/MEDLINE, SPORTDiscus and Web of Science following the preferred reporting items for systematic reviews and meta-analyses statement guidelines. A total of 52 meta-analyses were found, of which 14 met the inclusion criteria. These studies were published between 2009 and 2020 and comprised 178 primary studies corresponding to 4,784 participants. Following a methodological quality analysis, nine meta-analyses were categorized as high quality, presenting values of 81–88%. The remaining meta-analyses were rated as moderate quality, with values between 63–75%. Based on this umbrella review, we can state that at least 10 sets per week per muscle group is optimal, that eccentric contractions seem important, very slow repetitions (≥10 s) should be avoided, and that blood flow restriction might be beneficial for some individuals. In addition, other variables as, exercise order, time of the day and type of periodization appear not to directly influence the magnitude of muscle mass gains. These findings provide valuable information for the design and configuration of the resistance training program with the aim of optimizing muscle hypertrophy.

Resistance exercise training and the motor unit

Resistance exercise training (RET) is a key modality to enhance sports performance, injury prevention and rehabilitation, and improving overall health via increases in muscular strength. Yet, the contribution of neural mechanisms to increases in muscular strength are highly debated. This is particularly true for the involvement of the motor unit, which is the link between neural (activation) and mechanical (muscle fiber twitch forces) mechanisms. A plethora of literature that examines the effects of RET on skeletal muscle speculate the role of motor units, such as increases in firing rates partially explains muscular strength gains. Results, however, are mixed regarding changes in firing rates in studies that utilize single motor unit recordings. The lack of clarity could be related to vast or subtle differences in RET programs, methods to record motor units, muscles tested, types of contractions and intensities used to record motor units, etc. Yet to be discussed, mixed findings could be the result of non-uniform MU behavior that is not typically accounted for in RET research. The purpose of this narration is to discuss the effects of acute resistance exercise training studies on MU behavior and to provide guidance for future research.

Feasibility and acceptability of a remotely delivered, home-based, pragmatic resistance 'exercise snacking' intervention in community-dwelling older adults: a pilot randomised controlled trial

Background

Very few older adults meet current muscle strengthening exercise guidelines, and several barriers exist to supervised, community-based resistance exercise programs. Older adults therefore require access to feasible resistance exercise modalities that may be performed remotely. This pilot study assessed the feasibility and acceptability of undertaking a four-week home-based resistance ‘exercise snacking’ intervention (performed either once, twice, or thrice daily) when delivered and monitored remotely in older adults. 

Methods

Thirty-eight community-dwelling older adults [mean ± SD age 69.8 ± 3.8 y, 63% female] were randomised to complete resistance ‘exercise snacks’ (9-minute sessions) either once (n = 9), twice (n = 10), or thrice (n = 9) daily, or allocated to usual-activity control (n = 10). Exercise adherence and adverse events were assessed using an exercise diary, and acceptability of the intervention was explored using an online questionnaire. Physical function [balance, 5-times sit-to-stand (STS), and 30-second STS tests] was assessed remotely at baseline and follow-up using videoconferencing.

Results

The intervention was feasible and safe, with 100% participant retention, high adherence (97, 82, and 81% for once, twice, and thrice daily, respectively), and only two adverse events from a total of 1317 ‘exercise snacking’ sessions. The exercise intervention was rated as enjoyable (75% reported their enjoyment as ≥4 on a 5-point Likert scale), easy to perform, and most (82%) planned to continue similar exercise at home. We also found it was feasible to assess measures of physical function via videoconferencing, although effect sizes for 4-week changes in both 5-STS (d range, 0.4–1.4) and 30-STS (d range, 0.7–0.9) following the exercise intervention were similar to controls (d = 1.1 and 1.0 for 5-STS and 30-STS, respectively).

Conclusions

Resistance ‘exercise snacking’ may be a feasible strategy for engaging older adults in home-based resistance exercise when delivered and monitored remotely. The findings of this pilot feasibility trial support the need for longer-term studies in larger cohorts to determine the effectiveness of resistance ‘exercise snacking’ approaches for improving physical function in older adults.

Trial registration

The trial was retrospectively registered on 10/11/2021 with the Australian New Zealand Clinical Trials Registry (ANZCTR) (ACTRN12621001538831).

Depression and work productivity: insights from a longitudinal cohort study on digital care programs for Musculoskeletal conditions

BACKGROUND

Comorbidity between musculoskeletal (MSK) pain and depression is highly common and associated with greater symptom burden and greater loss of work productivity. Multimodal care programs tackling both physical and mental health components may maximize productivity recovery and return to work. Digital delivery of such programs can facilitate access, ensure continuity of care, and enhance patient engagement.

OBJECTIVE

Assess the impact of a completely remote multimodal digital care program (DCP) for MSK pain on mental health and work-related outcomes stratified by baseline depression levels.

METHODS

The present study is an ad-hoc analysis of an interventional, single-arm, cohort study of individuals with MSK pain undergoing a DCP. Three subgroups with different baseline depression severity levels were created based on the Patient Health Questionnaire (PHQ-9): cluster 1 (<5: minimal depression); cluster 2 (5-10: mild depression) and cluster 3 (≥10: moderate depression). The mean change between baseline and end-of-program (8-12 weeks) on depression, anxiety, fear-avoidance beliefs, work productivity and activity impairment and adherence was assessed across subgroups. Outcome changes were analyzed by latent growth curve analysis.

RESULTS

From a total of 7785 eligible participants, 6137 (78.8%) were included in Cluster 1, 1158 (14.9%) in cluster 2 and 490 (6.3%) in cluster 3. Significant improvements in depression and anxiety scores were observed in clusters 2 and 3 but not cluster 1, with average end-of-the program scores in clusters 2 and 3 below the initially defined cluster thresholds (5 and 10 for clusters 2 and 3, respectively). All clusters reported significant improvements in productivity impairment scores (mean changes from -16.82, 95%CI -20.32 to -13.42 in cluster 1 to -20.10, 95%CI -32.64 to -7.57 in cluster 3). Higher adherence was associated with higher improvements in depression in clusters 2 and 3, and with greater recovery in activities of daily living in cluster 3. Overall patient satisfaction was 8.59/10.0 (SD 1.74).

CONCLUSIONS

A multimodal DCP was able to promote improvements in productivity impairment scores comparable to those previously reported in the literature, even in participants with comorbid depression and anxiety. These results reinforce the need to follow a biopsychosocial framework to optimize outcomes in patients with MSK pain.

CLINICALTRIAL

ClinicalTrials.gov NCT04092946; https://clinicaltrials.gov/ct2/show/NCT04092946.

Impact of Flexibility on Vertical Jump, Balance and Speed in Amateur Football Players

Muscle strength, power, balance and speed assume decisive roles in football performance. This study aims to investigate whether lower limb flexibility, particularly the hip flexors and knee extensor and flexor muscles, are correlated with vertical jump performance, balance and speed in adult football players. A sample of 22 male amateur football players (age: 22.3 ± 3 years; height: 175.4 ± 7.4 cm; weight: 74.9 ± 11.6 kg; BMI: 24.2 ± 2.6 kg/m2) were assessed for lower limb flexibility, vertical jump, balance and speed. Results indicated that vertical jump ability is moderately correlated with left knee extensors flexibility (ρ = −0.426; p = 0.048), which did not occur on the right side. There were no statistically significant correlations between vertical jump and knee flexors flexibility (ρ = 0.330; p = 0.133). In balance, the reaching distance on the right side presented a moderate and statistically significant correlation with the knee flexors flexibility (ρ = 0.411; p = 0.040), which was not observed on the left side. Velocity was not correlated with the knee extensors flexibility (right: ρ = 0.360; p = 0.100; left: ρ = 0.386; p = 0.076), or with the knee flexors flexibility (ρ = −0.173; p = 0.440). In conclusion, the influence of flexibility on vertical jump ability, balance and speed appears to exist. Further research should seek to clarify the associations between these abilities.

Prescribing Intensity in Resistance Training Using Rating of Perceived Effort: A Randomized Controlled Trial

Introduction: Rating of perceived effort (RPE) scales are used to prescribe intensity in resistance training (RT) in several ways. For instance, trainees can reach a specific RPE value by modifying the number of repetitions, lifted loads, or other training variables. Given the multiple approaches of prescribing intensity using RPE and its growing popularity, we compared the effects of two RPE prescription approaches on adherence rates, body composition, performance and psychological outcomes, in an online RT intervention.

Methods: We randomly assigned 57 healthy participants without RT experience (60% females, age range: 18–45) to one of two groups that received two weekly RT sessions using a resistance-band for 8 weeks. In the fixed-repetition group, participants adjusted the band resistance with the goal of completing 10 repetitions and reaching a 7-RPE on a 0–10 scale by the 10th repetition. In the open-repetition group, participants selected their preferred band resistance and completed repetitions until reaching a 7-RPE by the final repetition. We measured body composition, performance, and program satisfaction rates.

Results: We assessed 46 participants at post-test, 24 from the fixed-repetition group and 22 from the open-repetition group. We observed non-significant and trivial differences between groups in all outcomes (p > 0.05). We then combined the pre-post change scores of the two groups. We found that adherence rates began at 89% and gradually decreased to 42%. On average, participants increased their fat-free mass [0.3 kg (95% CI: 0.1–0.6)], isometric mid-thigh pull [5.5 kg (95% CI: 0.8–10.4)], isometric knee-extension [2.2 kg (95% CI: 0.8–3.7)], and push-ups [6.3 repetitions (95% CI: 4.5–8.2)]. We observed non-significant and trivial changes in bodyweight, grip-force, and countermovement jump. Participants reported high satisfaction rates with all components of the program.

Conclusion: Participants in both groups improved their body composition and physical capacity to a similar extent, and reported comparable satisfaction rates with the programs they followed. Accordingly, either prescription approach can be used to deliver online RT sessions based on personal preferences and logistical constraints. However, since adherences rates declined over the course of the study, future research should test additional strategies aiming to maintain adherence rates.

Effects of a remote, YouTube-delivered exercise intervention on young adults' physical activity, sedentary behavior, and sleep during the COVID-19 pandemic: Randomized controlled trial

BACKGROUND

Public health guidelines have called for innovative and flexible physical activity (PA) intervention strategies to promote PA and health amid the coronavirus disease 2019 (COVID-19) pandemic. Therefore, this study's purpose was to examine the effects of a home-based, YouTube-delivered PA intervention grounded in self-determination theory on young adults' free-living PA, sedentary behavior, and sleep quality (NCT04499547).

METHODS

Sixty-four young adults (48 females; age = 22.8 ± 3.4 years, mean ± SD; body mass index = 23.1 ± 2.6 kg/m2) were randomized (1:1) into the intervention group, which received weekly aerobic and muscle-strengthening PA videos, or control group, which received weekly general health education videos, for 12 weeks. Our primary outcome was free-living moderate-to-vigorous PA (MVPA) and our secondary outcomes were sedentary behavior, light PA, and sleep quality (measured using ActiGraph accelerometers) along with muscle-strengthening PA frequency, self-determination theory-related motivation (non-regulation, external regulation, introjected regulation, identified regulation, integrated regulation, and intrinsic regulation), and perceived PA barriers (assessed using validated questionnaires). Repeated measures analysis of variances (ANOVAs) examined between-group differences at an adjusted significance level of 0.004 and effect sizes as partial eta-squared (ηp2).

RESULTS

We observed statistically significant interaction effects for MVPA, sleep efficiency, muscle-strengthening PA frequency, non-regulation, integrated regulation, intrinsic regulation, and perceived PA barriers (F(1, 62) = 10.75-77.67, p < 0.001-0.002, ηp2 = 0.15-0.56) with all outcomes favoring the intervention group. We observed no statistically significant differences in either group for sedentary behavior, light PA, sleep duration, or external, introjected, and identified regulations after 12 weeks (F(1, 62) = 1.11-3.64, p = 0.06-0.61).

CONCLUSION

With national COVID-19 restrictions still in place and uncertainty regarding post-pandemic PA environments and behaviors, a remote, YouTube-delivered PA intervention may help foster clinically meaningful improvements in young adults' free-living MVPA, muscle-strengthening PA frequency, sleep efficiency, PA-related intrinsic motivation, and perceived PA barriers.

Home-based, supervised, and mixed exercise intervention on functional capacity and quality of life of colorectal cancer patients: a meta-analysis

This systematic review and meta-analysis of randomized controlled trials tested the effects of home-based, supervised, or mixed exercise interventions on the functional capacity (FC) and quality of life (QoL) in colorectal cancer patients. A literature search was performed using the PubMed, Embase, Cochrane, and Medline databases. Two reviewers screened the literature through March 10, 2021 for studies related to exercise and colorectal cancer. Of the 1161 screened studies in the initial search, 13 studies met the eligibility criteria (home-based = 6 studies; supervised or mixed = 7 studies). Overall, 706 patients were enrolled in the trials, and 372 patients were submitted to home-based, supervised, or mixed exercise intervention. The overall results from the main meta-analysis showed a significant effect regarding supervised or mixed intervention (6 studies; p = 0.002; I² = 43%; PI 0.41–1.39); however, no significant effect was observed for home-based intervention (5 studies; p = 0.05; I² = 25%; PI − 0.34–0.76). A sensitivity analysis based on studies with intervention adherence ≥ 80% (home-based = 3 studies; supervised or mixed = 4 studies) revealed that home-based intervention or intervention entirely supervised or with some level of supervision (mixed) are effective in improving the QoL and FC of CRC patients. In summary, this meta-analysis verified that supervised and home-based exercise can modify QoL and FC when intervention adherence ≥ 80%. Regardless of the supervision characteristics, future RCTs are strongly encouraged to provide a detailed description of the exercise variables in physical interventions for CRC prescription. This perspective will allow a refined exercise prescription for patients with CRC, mainly according to their clinical status.

The Efficacy of Upper-Extremity Elastic Resistance Training on Shoulder Strength and Performance: A Systematic Review

Elastic resistance exercise is a popular mode of strength training that has demonstrated positive effects on whole-body strength and performance. The purpose of this work was to identify the efficacy of elastic resistance training on improving upper limb strength and performance measures for the shoulder. Seven online databases were searched with a focus on longitudinal studies assessing shoulder elastic training strength interventions. In total, 1367 studies were initially screened for relevancy; 24 full-text articles were included for review. Exercise interventions ranged from 4-12 weeks, assessing pre-/post-strength and performance measures inclusive of isometric and isokinetic strength, 1RM strength, force-velocity tests, and throwing-velocity tests. Significant increases in various isometric strength measures (IR:11–13%, ER:11–42%, FL: 14–36%, EXT: 4–17%, ABD: 8–16%), 1RM strength (~24% in bench press), force-velocities, throwing- and serve-velocities (12%) were all observed. Elastic resistance training elicited positive effects for both strength and performance parameters regardless of intervention duration. Similar significant increases were observed in isometric strength and 1RM strength across durations. Isokinetic strength increases were variable and dependent on the joint velocity conditions. Quantifying the dosage of appropriate exercise prescription for optimal strength and performance gains is inconclusive with this study due to the heterogeneity of the intervention protocols.

A comparison of augmented feedback and didactic training approaches to reduce spine motion during occupational lifting tasks

Manual handling training may be improved if it relied on the provision of individualized, augmented feedback about key movement features. The purpose of this study was to compare the reduction in sagittal spine motion during manual lifting tasks following two training approaches: didactic (DID) and augmented feedback (AUG). Untrained participants (n = 26) completed lifting tests (box, medication bag, and paramedic backboard) and a randomly-assigned intervention involving 50 practice box lifts. Lifting tests were performed immediately before and after training, and one-week after interventions. Both groups exhibited reductions in spine motions immediately and one-week after the interventions. However, the AUG intervention group elicited significantly greater reductions in 5 of 12 between-group comparisons (3 tasks × 4 spine motion variables). The results of the current study support the use of augmented feedback-based approaches to manual handling training over education-based approaches.