A Comparison of Muscle Activation between Barbell Bench Press and Dumbbell Flyes in Resistance-Trained Males

The purpose of the study was to compare the muscle activity in the prime movers and antagonist between the barbell bench press (BBP) and the dumbbell flyes (DF) Seventeen resistance-trained men (age 22.9 ± 1.8 yrs; height 1.80 ± 0.06 m; body mass 80.0 ± 8.3 kg), with 4.8 ± 2.0 years resistance training experience, completed the study. The surface electromyographic activation was measured in four different muscles (pectoralis major, anterior deltoids, triceps brachii, and biceps brachii) during six repetition maximum loads in both exercises. To better understand eventual differences, an in-depth analysis of the fifth repetition was performed, dividing it into six phases (lower, middle, and upper phase of the descending and ascending movement). The results showed a higher muscle activation in the whole movement and the majority of the lifting phases for pectoralis major, deltoids anterior, and triceps brachii for the BBP compared to the DF (8-81 %, p ≤ 0.05). However, the antagonist biceps brachii showed a higher muscle activation (57-86 %, p ≤ 0.05) in the DF compared to the BBP. In conclusion, both exercises could be included in training programs, but the BBP should be emphasized because of the higher muscle activation overall. Among specific populations, were tasks based on strength and control in a horizontal shoulder flexion position with extended elbows often occurs, the DF might prove useful.

Cardiovascular Acute Effects of Traditional vs. Paired Set Resistance Training in Patients With Liver Cirrhosis

Purpose: This study compared the acute effects of two different resistance training methods on heart rate variability, blood pressure, and rating of perceived exertion in patients with liver cirrhosis. Methods: Ten patients with Child-Pugh A (seven women and three men) participated in two experimental sessions, in random order: The traditional set condition consisted of three sets of six exercises performed in a sequential manner, while the paired set condition consisted of alternating sets between two exercises (three pairs of exercises). Ten repetitions were performed for each set with 70% of a 10 repetition maximum load and with 2 min rest between sets. Blood pressure and heart rate variability were assessed pre-workout and for 60 min post-workout. The rating of perceived exertion was assessed at the end of the third set for each exercise. Results: Significant alterations in heart rate variability were observed when considering the lowest value obtained during recovery, in which the SDNN was reduced in both the traditional set and paired set conditions, as well as the root mean square of standard deviation for the traditional set condition (p < .05). Additionally, for the paired set condition, there was a significant reduction in the HFnu band and a significant increase in the LFnu band (p < .05). Effect size showed reductions in diastolic and mean blood pressure until 30 min in a small magnitude for traditional sets. Conclusion: Similar cardiovascular responses were observed between methods eliciting normal physiological responses within safe limits for patients with liver cirrhosis.

A Systematic Review of Workplace Interventions to Rehabilitate Musculoskeletal Disorders Among Employees with Physical Demanding Work

Purpose This systematic review investigates the effectiveness of workplace interventions to rehabilitate musculoskeletal disorders (MSDs) among employees with physically demanding work. Methods A systematic search was conducted in bibliographic databases including PubMed and Web of Science Core Collection for English articles published from 1998 to 2018. The PICO strategy guided the assessment of study relevance and the bibliographical search for randomized controlled trials (RCTs) and non-RCTs in which (1) participants were adult workers with physically demanding work and MSD (including specific and non-specific MSD and musculoskeletal pain, symptoms, and discomfort), (2) interventions were initiated and/or carried out at the workplace, (3) a comparison group was included, and (4) a measure of MSD was reported (including musculoskeletal pain, symptoms, prevalence or discomfort). The quality assessment and evidence synthesis adhered to the guidelines developed by the Institute for Work & Health (Toronto, Canada) focusing on developing practical recommendations for stakeholders. Relevant stakeholders were engaged in the review process. Results Level of evidence from 54 high and medium quality studies showed moderate evidence of a positive effect of physical exercise. Within this domain, there was strong evidence of a positive effect of workplace strength training. There was limited evidence for ergonomics and strong evidence for no benefit of participatory ergonomics, multifaceted interventions, and stress management. No intervention domains were associated with "negative effects". Conclusions The evidence synthesis recommends that implementing strength training at the workplace can reduce MSD among workers with physically demanding work. In regard to workplace ergonomics, there was not enough evidence from the scientific literature to guide current practices. Based on the scientific literature, participatory ergonomics and multifaceted workplace interventions seem to have no beneficial effect on reducing MSD among this group of workers. As these interventional domains were very heterogeneous, it should also be recognized that general conclusions about their effectiveness should be done with care.Systematic review registration PROSPERO CRD42018116752 ( https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=116752 ).

Both the resistance training session and the static stretching after exercise does not affect the pectoralis major stiffness of well-trained men

Previous evidence suggests the intense resistance training session can increase the muscle hardness, while stretching protocols with high intensity and volume can decrease it. However, it remains unknown the effects of an exercise and a less intensive stretching maneuver on muscle stiffness of well-trained men. Herein we (i) analyze the acute effects of heavy bench press exercise on the pectoralis major muscle shear modulus of well-trained men and (ii) assess the effectiveness of a 1-min stretching maneuver applied on this muscle after the exercise using shear wave elastography. Fourteen participants performed three sets of bench press from 8 to 13 repetitions maximum. Immediately after the exercise, their right shoulder was passively stretched for 1 min (stretched side) while their left arm stayed relaxed along the side of the body (control side). Elastographic images were acquired for the pectoralis major mid-region of both sides before the exercise, immediately after the intervention and after 5 min of rest. Our results revealed that both the bench press exercise and the static stretching does not affect the pectoralis major shear modulus of well-trained men. Conversely, the shear modulus significantly decreased at 5 min after intervention with respect to immediately after, for both the stretched (from 5.52 to 4.29 kPa) and the control sides (from 5.87 to 4.56 kPa). Therefore, both resistance training session and 1-min static stretching were not sufficient to significantly change the pectoralis major muscle stiffness of well-trained men.

Impact of resistance training status on trunk muscle activation in a fatiguing set of heavy back squats

Purpose

In this study we measured neural activation (EMG) in four trunk stabilizer muscles and vastus lateralis (VL) in trained and novice participants during a set of squat repetitions to volitional fatigue at 85% 1RM.

Methods

Forty males were recruited into two groups, novice (NG: n = 21) and experienced (EG: n = 19), according to relative squat 1RM. Participants were tested twice to: (1) determine squat 1RM, and (2) complete a single set of repetitions to volitional fatigue at 85% 1RM. Relative squat 1RM; NG < 140% body mass, EG > 160% body mass. Neuromuscular activation was measured by EMG for the following: rectus abdominus (RA), external oblique (EO), lumbar sacral erector spinae (LSES), upper lumbar erector spinae (ULES) and VL in eccentric and concentric phase. Completed repetitions, RPE and EMG in repetition 1 and at 20, 40, 60, 80 and 100% of completed repetitions were analysed.

Results

No group differences were found between number repetitions completed and RPE in repetitions to volitional fatigue at 85% 1RM. Neuromuscular activation increased significantly in all muscle groups in eccentric and concentric phase apart from RA in the eccentric phase. Trunk neuromuscular activation was higher in NG compared to EG and this was significant in EO, LSES and ULES in eccentric phase and LSES in the concentric phase. VL activation increased in both phases with no group differences.

Conclusion

Trunk neuromuscular activation increases in a fatiguing set of heavy squats regardless of training status. Increased back squat strength through training results in lower neuromuscular activation despite greater absolute external squat loads.

Benefits of Resistance Training in Older Adults

Aging is a natural process that may lead to detrimental health depending on someone's lifestyle, family history, psychological/psychosocial health, chronic medical conditions, and genetics. However, whether the later conditions lead to faster aging or vice versa, maintaining a healthy lifestyle and psychological health has been shown to delay the process of aging and its associated problems. Two major problems that older adults face today are the inability to perform everyday tasks (defined as activities of daily living) and the increased risk of falls. Lack of muscular function (including neuromuscular function) and bone health is associated with the inability to perform the Activity of Daily Living (ADL) and increased risk of falls. This risk of falls has been associated with cardiovascular-related mortality in older adults. Research has shown that resistance exercises can maintain normal blood glucose levels, lipids, and cholesterol, and hence the management of chronic conditions like cardiovascular diseases and diabetes mellitus. Additionally, resistance exercises hinder the process of muscular (and neuromuscular) damage, improve bone health and psychological health and sleep. This mini-review will discuss the benefits of resistance exercises on reversing or at least ceasing the process of developing conditions associated with aging.

Moving forward with backward pedaling: a review on eccentric cycling

PURPOSE

There is a profound gap in the understanding of the eccentric cycling intensity continuum, which prevents accurate exercise prescription based on desired physiological responses. This may underestimate the applicability of eccentric cycling for different training purposes. Thus, we aimed to summarize recent research findings and screen for possible new approaches in the prescription and investigation of eccentric cycling.

METHOD

A search for the most relevant and state-of-the-art literature on eccentric cycling was conducted on the PubMed database. Literature from reference lists was also included when relevant.

RESULTS

Transversal studies present comparisons between physiological responses to eccentric and concentric cycling, performed at the same absolute power output or metabolic load. Longitudinal studies evaluate responses to eccentric cycling training by comparing them with concentric cycling and resistance training outcomes. Only one study investigated maximal eccentric cycling capacity and there are no investigations on physiological thresholds and/or exercise intensity domains during eccentric cycling. No study investigated different protocols of eccentric cycling training and the chronic effects of different load configurations.

CONCLUSION

Describing physiological responses to eccentric cycling based on its maximal exercise capacity may be a better way to understand it. The available evidence indicates that clinical populations may benefit from improvements in aerobic power/capacity, exercise tolerance, strength and muscle mass, while healthy and trained individuals may require different eccentric cycling training approaches to benefit from similar improvements. There is limited evidence regarding the mechanisms of acute physiological and chronic adaptive responses to eccentric cycling.

Prediction of muscle fiber composition using multiple repetition testing

Direct determination of muscle fiber composition is invasive and expensive, with indirect methods also requiring specialist resources and expertise. Performing resistance exercises at 80% 1RM is suggested as a means of indirectly estimating muscle fiber composition, though this hypothesis has never been validated against a direct method. The aim of the study was to investigate the relationship between the number of completed repetitions at 80% 1RM of back squat exercise and muscle fiber composition. Thirty recreationally active participants’ (10 females, 20 males) 1RM back squat load was determined, before the number of consecutive repetitions at 80% 1RM was recorded. The relationship between the number of repetitions and the percentage of fast-twitch fibers from vastus lateralis was investigated. The number of completed repetitions ranged from 5 to 15 and was independent of sex, age, 1RM, training frequency, training type, training experience, BMI or muscle fiber cross-sectional area. The percentage of fast-twitch muscle fibers was inversely correlated with the number of repetitions completed (r = –0.38, P = 0.039). Participants achieving 5 to 8 repetitions (n = 10) had significantly more fast-twitch muscle fibers (57.5 ± 9.5 vs 44.4 ± 11.9%, P = 0.013) than those achieving 11–15 repetitions (n = 11). The remaining participants achieved 9 or 10 repetitions (n = 9) and on average had equal proportion of fast- and slow-twitch muscle fibers. In conclusion, the number of completed repetitions at 80% of 1RM is moderately correlated with muscle fiber composition.

Maintenance of muscle strength following a one-year resistance training program in older adults

BACKGROUND

Muscle mass, strength and function declines with advancing age. Strength training (ST) improves these parameters in older adults, but the gains often disappear after completion of a short-term intervention. The purpose of the present study was to investigate muscle mass, -strength and -function one year after the completion of a successful long-term (12 months) supervised ST program in older adults.

METHOD

Men and women (n = 419, age: 62-70 years) completed one year of supervised heavy resistance training (HRT, n = 143) or moderate intensity resistance training (MIT, n = 144) and were compared to a non-exercising control group (CON, n = 132). At 1-year follow-up, 398 participants returned for measurements of muscle power, -strength and -mass, physical function, body composition, hippocampus volume and physical/mental well-being. The results were compared to pre-training (baseline) and post-training (1-year) values. Further, the participants from the two previous training groups (HRT + MIT, n = 265) were divided into 1) those who on their own continued the ST program (>9 months) the year after completion of the supervised ST program (CONTIN, n = 65) and 2) those who stopped during the follow-up year (<9 months) (STOP, n = 200).

RESULTS

Out of all the improvements obtained after the 1-year training intervention, only knee extensor muscle strength in HRT was preserved at 1-year follow-up (p < 0.0001), where muscle strength was 7% higher than baseline. Additionally, the decrease in muscle strength over the second year was lower in CONTIN than in STOP with decreases of 1% and 6%, respectively (p < 0.05). Only in CONTIN was the muscle strength still higher at 1-year follow-up compared with baseline with a 14% increase (p < 0.0001). The heavy strength training induced increase in whole-body lean mass was erased at 1-year follow-up. However, there was a tendency for maintenance of the cross-sectional area of m. vastus lateralis from baseline to 1-year follow-up in HRT compared with CON (p = 0.06). Waist circumference decreased further over the second year in CONTIN, whereas it increased in STOP (p < 0.05).

CONCLUSION

Even though long-term strength training effectively improved muscle function and other health parameters in older adults, only knee extensor muscle strength was preserved one year after completion of heavy (but not moderate intensity) resistance training. Continuation of strength training resulted in better maintenance of muscle strength and health, which indicates that it is required to continue with physical activity to benefit from the long-term effects of strength training upon muscle function and health in older men and women.

Effects of a single bout of power exercise training on ambulatory blood pressure in older adults with hypertension: A randomized controlled crossover study

OBJECTIVE

To evaluate the effect of a single bout of power exercise training (PT) on office and ambulatory blood pressure (BP).

METHODS

Twenty-four older adults with essential hypertension participated in two experimental sessions in a randomized order: the PT composed of 3 sets of 8-10 repetitions in 5 power training exercises and the non-exercise control at seated rest (Con). Both experimental sessions lasted 40 min. Office BP was measured continuously for 1 h in the laboratory and 24 h BP through ambulatory blood pressure monitoring.

RESULTS

Compared with Con, office systolic/diastolic BP decreased after PT (Systolic BP: 10 mmHg, p < 0.001; Diastolic BP: 4 mmHg, p = 0.015). A trend toward decrease (p = 0.06) was found in diastolic ambulatory BP during daytime (2 mmHg; p = 0.062) and nighttime (3 mmHg; p = 0.063) after PT. No differences were found between PT and Con sessions for systolic and mean ambulatory BP.

CONCLUSION

A single bout of PT decreases office BP but this hypotensive effect is not sustained under ambulatory conditions in older patients with essential hypertension.

Running coaches and running group leaders' engagement with, and beliefs and perceived barriers to prehabilitation and injury prevention strategies for runners

OBJECTIVES

To identify which pre-and post-run injury risk reduction activities and prehabilitation (prehab) strategies Coaches and Running Group Leaders (Coaches/RGLs) engage in with runners; to explore their beliefs on why runners get injured; to identify Coaches/RGLs confidence providing injury prevention activities, and what they believe are effective for reducing risk of injury; to identify their perceived barriers to including prehab during running coaching/training.

DESIGN

Survey; Participants: UK Coaches/RGLs (N = 100) OUTCOME MEASURES: Online questionnaire with open, closed and Likert scale questions.

RESULTS

Most Coaches/RGLs performed active warm-ups (97%), cool-downs (94%),gave injury prevention advice (91%), and advice on recovery strategies (84%) during training. Fewer coaches/RGLs incorporated prehab (67%). Although they collectively exhibited a wide range of knowledge, individually there was less consistency and confidence providing this. Prehab was rated as very important for injury risk reduction, with supervision recommended to facilitate runner engagement. Coaches/RGLs found conflicting advice, time, environment, and resistance from runners as barriers to incorporating prehab into training.

CONCLUSION

Coaches/RGLs believe prehab is important for runners however lack of confidence and knowledge appeared to limit the wider inclusion of prehab with runners. Coaches/RGLs welcomed reputable information on prehab from evidence-based sources. This may assist in reducing injury.

Muscle-strengthening Exercise Epidemiology: a New Frontier in Chronic Disease Prevention

This current opinion provides an overview of the emerging discipline of muscle-strengthening exercise epidemiology. First, we define muscle-strengthening exercise, and discuss its recent addition into the global physical activity guidelines, which were historically mainly focused on aerobic physical activity (walking, running, cycling etc.). Second, we provide an overview of the current clinical and epidemiological evidence on the associations between muscle-strengthening exercise and health, showing a reduced mortality risk, and beneficial cardiometabolic, musculoskeletal, functional and mental health-related outcomes. Third, we describe the latest epidemiological research on the assessment, prevalence, trends and correlates of muscle-strengthening exercise. An overview of recent population estimates suggests that the proportion of adults meeting the current muscle-strengthening exercise guideline (10-30%; ≥ 2 sessions/week) is far lower than adults reporting meeting the aerobic exercise guideline (~ 50%; ≥ 150 min/week). Fourth, we discuss the complexity of muscle-strengthening exercise promotion, highlighting the need for concurrent, coordinated, and multiple-level strategies to increase population-level uptake/adherence of this exercise modality. Last, we explore key research gaps and strategies that will advance the field of muscle-strengthening exercise epidemiology. Our objective is to provide a case for increased emphasis on the role of muscle-strengthening exercise for chronic disease prevention, and most importantly, stimulate more research in this currently understudied area of physical activity epidemiology.

Acute effects of body-weight resistance exercises on blood pressure and glycemia in middle-aged adults with hypertension

OBJECTIVE

The purpose of the present study was to evaluate the acute effects of single session of body-weight resistance exercises on blood pressure (BP) and glycemia in middle-aged adults with hypertension.

METHODS

Twenty-three participants took part in this trial with crossover design and performed two experimental sessions in a random order: Body-weight resistance exercise session (BWR) and a control session without exercise. BWR was composed of four exercises: inverted row, squat, , and sit-ups. The participants performed 3 sets of 30 s, in which they were instructed to perform as much repetitions as possible and as fast as possible. After each session, BP and glycemia were measured continuously for 60 min.

RESULTS

Systolic BP decreased after BWR when compared with control at post 45': -7 (95%CI:-11 to -2) mmHg, p = .003 and post60': -7 (95%CI:-12 to -3) mmHg, p = .003. Diastolic BP decreased after BWR when compared with control at post 15': -6 (95%CI:-9 to -3) mmHg, p < .001; post 30': -6 (95%CI:-9 to -2) mmHg, p = .001; post45': -5 (95%CI:-9 to -2) mmHg, p = .005; and post60': -6 (95%CI: -8 to -3) mmHg, p < .001. No significant difference was found in glycemia between BWR and control sessions.

CONCLUSION

BWR acutely reduces BP in middle-aged adults with hypertension without effects on usual glycemia responses. This alternative form of resistance training could facilitate access, adherence, and reduce health costs related to exercise programs.

Effectiveness of a resistance training program on physical function, muscle strength, and body composition in community-dwelling older adults receiving home care: a cluster-randomized controlled trial

Background

Aging is associated with reduced muscle mass and strength leading to impaired physical function. Resistance training programs incorporated into older adults' real-life settings may have the potential to counteract these changes. We evaluated the effectiveness of 8 months resistance training using easily available, low cost equipment compared to physical activity counselling on physical function, muscle strength, and body composition in community-dwelling older adults receiving home care.

Methods

This open label, two-armed, parallel group, cluster randomized trial recruited older adults above 70 years (median age 86.0 (Interquartile range 80-90) years) receiving home care. Participants were randomized at cluster level to the resistance training group (RTG) or the control group (CG). The RTG trained twice a week while the CG were informed about the national recommendations for physical activity and received a motivational talk every 6th week. Outcomes were assessed at participant level at baseline, after four, and 8 months and included tests of physical function (chair rise, 8 ft-up-and-go, preferred- and maximal gait speed, and stair climb), maximal strength, rate of force development, and body composition.

Results

Twelve clusters were allocated to RTG (7 clusters, 60 participants) or CG (5 clusters, 44 participants). The number of participants analyzed was 56-64 (6-7 clusters) in RTG and 20-42 (5 clusters) in CG. After 8 months, multilevel linear mixed models showed that RTG improved in all tests of physical function and maximal leg strength (9-24%, p = 0.01-0.03) compared to CG. No effects were seen for rate of force development or body composition.

Conclusion

This study show that resistance training using easily available, low cost equipment is more effective than physical activity counselling for improving physical function and maximal strength in community-dwelling older adults receiving home care.

Trial registration

ISRCTN1067873.

Effects of progressive resistance training prior to total HIP arthroplasty - a secondary analysis of a randomized controlled trial

OBJECTIVE

To investigate 1-year postoperative effect of preoperative resistance training (RT) in patients undergoing total hip arthroplasty (THA) on patient-reported outcomes on activity and function and objective outcomes on muscle strength and physical performance.

DESIGN

A 3-12 months follow-up of a randomized controlled trial. Patients scheduled for THA were randomized into: RT-group, twice a week for 10 weeks prior to THA, or 'care-as-usual' (CG). Primary endpoint of this sequel analysis is HOOS-ADL at 12 months follow-up. Secondary outcome measures are; other HOOS subscales, knee- and hip muscle strength plus function (gait, ascending/descending stairs, and sit-to-stand) at three and/or 12 months. CLINICALTRIALS.GOV: NCT01164111.

RESULTS

Eighty patients (70% women, 70.4 ± 7.6 years, BMI of 27.8 ± 4.6) were randomized to RT (n = 40) or CG (n = 40); data from 85% were available at 12 months. No superior effects were observed at 12 months for HOOS ADL (between-group change score [95%CI]) (2.6 [-4.2; 9.8], P = 0.44) or remaining subscales. However, ascending (1.3 s [0.3; 2.3], P = 0.01)) and descending stairs (1.6 s [0.3; 2.9], P = 0.01) demonstrated additional effects. At 3 months clinically relevant change-scores in favour of RT was observed on HOOS-Sport/Rec (10.5 points [1.4; 19.6], P = 0.023), together with higher knee strength of the affected side (14.6 Nm [6.3; 22.9], P < 0.001), and selected outcomes of physical function.

CONCLUSIONS

At 12 months after surgery, there was no additional effect of preoperative RT compared with THA alone, but rehabilitation was accelerated at 3 months.

To Study the Effect of Calorie Deficit Diet and Strength Training in Patients with Mild to Moderate Obstructive Sleep Apnoea

OSA is a disease of modernisation. Though many modalities are available for its treatment from invasive to non-invasive; the role of lifestyle modification can never be underrated. Lifestyle modification normally includes walk; diet with less fat; abstinence from alcohol and smoking along with regularising of sleep schedule. However the role of calorie deficit diet along with strength training in OSA has not been extensively researched till date. The present study aimed to evaluate the effect of the calorie deficit diet and strength training in patients with mild to moderate obstructive sleep apnea. It is a prospective randomised control trial of 40 patients. The patients were divided into 2 groups. Group A was given lifestyle modification while Group B was given Lifestyle Modification with calorie deficit diet and strength training. The outcomes were measured by comparing pre-intervention and post-intervention polysomnography and Epworth sleepiness score after 3 months. The most common symptom found in our group was excessive daytime sleepiness and Loud snoring; both present in 39/40 patients. Other common symptoms were Awakening with a dry mouth or sore throat; morning headache; difficulty concentrating during the day; experiencing mood changes, such as depression or irritability and high blood pressure. The post intervention BMI in Group A was - 1.75 ± 0.698 than pre-intervention BMI while in Group B the difference between pre-intervention and post intervention was - 3.05 ± 1.32. The difference in AHI events pre-intervention versus post-intervention in Group A and Group B was - 3.5 ± 1.11 and - 5.55 ± 1.90 respectively. The ESS decreased by - 2.2 ± 0.871 and - 3.31 ± 0.05 respectively in Group A and Group B post-intervention. Calorie deficit diet along with strength training markedly improves the AHI index; BMI and ESS score in Mild to moderate OSA patients and is highly recommended in motivated patients in addition to lifestyle modification.

Sex Difference in Participation in Muscle-Strengthening Activities

Background

Previous data from the United States Centers for Disease Control and Prevention indicate men are more likely than women to participate in muscle-strengthening activities (e.g., resistance training). However, a recent review by Rhodes et al. concluded there is no reliable sex difference in participation. The purpose of the current paper was to review population-level surveys of participation in muscle-strengthening activities to clarify if a sex difference in participation exists.

Methods

Keyword searches (e.g., "resistance training participation") were performed in PubMed and Google Scholar to identify papers that surveyed a general adult population (N > 1,000) and reported an outcome of the proportion of the population meeting recommendations for "muscle-strengthening activities" (i.e., ≥ 2 times/wk) or participating in resistance training.

Results

Sixteen studies from 6 countries met the inclusion criteria. Irrespective of the measure of participation, population-levels of participation were typically higher in men than women. More men than women met recommendations for muscle-strengthening activities in England (men 34%; women 24%), Finland (men 18.1%; women 16.4%), Northern Ireland (men 25%; women 14%), Scotland (men 30%; women 25%), and the United States (men 34.8%; women 25.8%). For Australia, some studies showed no sex difference in participation, whereas other studies showed greater participation among men.

Conclusion

A sex difference exists in participation in muscle-strengthening activities. Low participation rates in both sexes indicate efforts to encourage participation in men and women are warranted. The results also highlight the need for rigorous definitions of "participation," as the lack of such definitions explains the mixed results reported previously.

Effects of high-protein diet combined with exercise to counteract frailty in pre-frail and frail community-dwelling older adults: study protocol for a three-arm randomized controlled trial

Background

The proportion of older citizens is increasing worldwide. A well-known syndrome in old age is physical frailty which is associated with a greater risk of disabilities in activities of daily living, greater reliance on in-home services, hospitalization, institutionalization, and premature mortality. The purpose of this study is to determine the effects of an intervention with high-protein diet alone or in combination with power training in pre-frail and frail old adults.

Methods

The study is a community-based assessor-blinded parallel randomized controlled trial (RCT), consisting of two phases. Phase 1 is a 1-month stabilization phase, where self-reliant community-dwelling adults + 80 years old will receive individual guidance regarding protein intake, to prevent the risk of negative protein balance prior to phase 2 and to only include participants who have reached the minimum recommended level of protein intake (1.0 g/kg/day) in the randomized controlled trial. Phase 2 is a 4-month RCT where 150 participants will be randomized into the following three arms: protein-only where participants will be provided with dairy products to increase their protein intake to 1.5 g/kg/day, protein + exercise where participants will be provided with the protein intervention in combination with power training two times a week, and recommendation group where participants will continue as in phase 1. Primary outcome is lower leg muscle power. Secondary outcomes include physical function and mobility, frailty status, muscle mechanical function, body composition, nutritional status, and health-related quality of life. The statistical analysis will include an intention-to-treat analysis of all randomized participant and per-protocol analysis of all compliant participants. The study hypothesis will be tested with mixed linear models to assess changes in the main outcomes over time and between study arms.

Discussion

The finding of this study may add to the knowledge about the beneficial effects of high-protein diet from dairy products combined with power training to counteract frailty in community-dwelling older adults. This may ultimately have an impact on the ability to live well and independent for longer.

Trial registration

ClinicalTrials.gov NCT03842579. Registered on 15 February 2019, version 1

Cross-validity of one maximum repetition predictive equation for men with spinal cord injury

Objectives: The study aimed to test the cross-validation of a specific one maximum repetition (1RM) predictive equation based on the 4- to 12-maximum repetition test (4-12RM) for men with spinal cord injury (SCI). Study design: Cross-sectional study. Setting: Rehabilitation Hospital Network. Participants: Fifty-eight men aged 31.9 (20.0-38.0) years (median and quartile) with SCI were enrolled in the study. Interventions: None. Outcomes measures: Volunteers were tested in 1RM test or 4-12RM of the bench press exercise with 2-3 interval days in a random order. The intraclass correlation coefficient (ICC) with Bland Altman plot was used to compare a specific predictive equation (SPE) and six current predictive equations (CPE) based on the 4- to 12-maximum repetition with the 1RM test. Results: The SPE showed the highest intraclass correlation coefficient (ICC = 0.91; 95%CI 0.85-0.95), the smallest range of the interval around the differences (Δ = 36.6) and the second lowest mean difference between 1RM test and 1RM predictive equation (-2.4 kg). The CPE3 presented the lowest mean difference (-1.6 kg). All intraclass correlations' predictive equations were classified as excellent. Conclusion: The SPE presented a suitable and satisfactory validity to assess men with SCI at the bench press exercise. Thus, the equation is an accurate method to predict 1RM in SCI.

Study protocol of a randomized intervention study to explore effects of a pure physical training and a mind-body exercise on cognitive executive function in independent living adults age 65-85

BACKGROUND

Decline in cognitive function associated with aging is one of the greatest concerns of older adults and often leads to a significant burden for individuals, families, and the health care system. Executive functions are most susceptible to age-related decline. Despite the well-known benefits of regular exercise on cognitive health, older adults tend to be less physically active than other age groups. Thus, there is a need to identify strategies that attract older adults and can enhance cognitive vitality.

AIMS

This article describes the protocol of a study designed to evaluate whether two interventions, a pure physical exercise and a mind-body exercise, can improve cognitive executive function in independent-living older adults. In addition, the study will explore barriers/facilitators related to adherence.

METHODS

After baseline assessment, participants will be randomly assigned to one of three groups (strength training, Awareness Through Movement^®, or a control group). Participants of the two active groups will attend the interventions for 12 weeks. The control group continues with the usual everyday life. Assessments will include three measures of executive function of the NIH Toolbox, and are administered at baseline, post-intervention and at 3-month follow-up. The primary outcomes are the changes in cognitive executive function performances. Secondary outcomes include adherence, self-efficacy for exercise, symptoms of depression, mindfulness and enjoyment. Attendance will be used as a measure of adherence.

DISCUSSION AND CONCLUSION

If successful, the interventions could provide low-cost strategies for older adults to maintain cognitive vitality and has the potential to impact current exercise guidelines.

The impact of acute and chronic resistance exercise on muscle stiffness: a systematic review and meta-analysis

PURPOSE

Ultrasound is commonly used to measure changes in skeletal muscle morphology in response to both acute and chronic resistance exercise, but little is known on how muscle stiffness changes via ultrasound elastography, which was the purpose of this systematic review and meta-analysis.

METHODS

The online data bases of Pubmed, Scopus, and Web of Science were each searched up until February 2020 and the data were analyzed using a random effects model.

RESULTS

A total of eight studies (four acute and four chronic) met the inclusion criteria for the quantitative analysis. Following a single bout of exercise, muscle stiffness was increased within the first hour [ES: 1.52 (95% CI 0.14, 2.91); p = 0.031], but was no longer elevated when measured 2 days post-exercise [ES: 0.76 (95% CI - 0.32, 1.83); p = 0.16] or ≥ 7 days post-exercise [ES: 0.20 (95% CI - 0.53, 0.94); p = 0.58]. There was no impact of long-term resistance training on changes in muscle stiffness [ES: - 0.04 (95% CI - 0.24, 0.15); p = 0.653].

CONCLUSION

The primary findings from this meta-analysis indicate that muscle stiffness increases acutely following a single bout of resistance exercise, but does not change long-term with chronic resistance training when measured via ultrasound shear elastography. Given the small number of studies included in this review, future studies may wish to examine changes in muscle stiffness in response to both acute and chronic resistance exercise.

High-intensity resistance training induces changes in cognitive function, but not in locomotor activity or anxious behavior in rats induced to type 2 diabetes

Type 2 diabetes (T2D) is a metabolic disorder that can lead to cognitive decline through impairment of insulin signaling. Resistance training, a type of physical exercise, is a non-pharmacological approach used to improve insulin resistance in T2D. The aim of our study was to evaluate the effects of high-intensity resistance training (HIRT) over cognitive function, locomotor activity, and anxious behavior in rats induced to T2D. Thirty young adult male wistar rats were distributed into 3 groups (n = 10): Control; dexamethasone (D); and dexamethasone + exercise (DE), that performed the HIRT during 4 weeks. Blood glucose, water intake, and total body fat were measured. Locomotor activity, and anxious behavior where evaluated through the open field task. Cognitive function was assessed through the novel object recognition task. Insulin resistance and neuronal death were evaluated through western blot analysis. Rats induced to T2D had higher blood glucose levels, and consumed more water when compared to control group, but DE had better blood glucose levels than D. Total body fat was reduced in DE compared to D. Locomotor activity, and anxious behavior were not significantly altered. T2D rats which performed HIRT maintained cognitive function, while those induced to T2D that did not exercise developed cognitive decline. DE group showed a reduction in the inhibition of the activation of hippocampal IRS-1 and higher expression of GSk3β phosphorylated in serine compared to D group, revealing insulin signaling impairment, and neuronal death were identified in the hippocampus of D group. Lifestyle intervention through the regular practice of HIRT plays a fundamental role in the treatment of T2D preventing cognitive decline.

Low-dose strength training in addition to neuromuscular exercise and education in patients with knee osteoarthritis in secondary care - a randomized controlled trial

OBJECTIVES

To investigate the effects of lower limb strength training in addition to neuromuscular exercise and education (ST + NEMEX-EDU) compared to neuromuscular exercise and education alone (NEMEX-EDU) on self-reported physical function in patients with knee osteoarthritis (KOA).

DESIGN

Patient-blinded, parallel-group randomized controlled trial (RCT).

METHODS

The trial included 90 patients in secondary care with radiographic and symptomatic KOA, ineligible for knee replacement. Both groups exercised twice weekly for 12 weeks. Additional strength training consisted of a single, fatiguing knee extension set (30-60RM) before four sets of leg-press (8-12RM). Primary outcome was the between-group difference on the subscale activities of daily living from the Knee Injury and Osteoarthritis Outcome Score (KOOS_ADL) at 12 weeks. Secondary outcomes included KOOS symptoms, pain, function in sport and recreation, and quality of life, 40 m walk, stair climb, leg extension power, EuroQol-5D-5L, pain medication usage, and adverse events.

RESULTS

There was no statistically significant between-group difference in KOOS_ADL at 12-weeks; adjusted mean difference -1.15 (-6.78 to 4.48). Except for the stair climb test, which demonstrated an adjusted mean difference of 1.15 (0.09-2.21) in favor of ST + NEMEX-EDU, all other outcomes showed no statistically significant between-group differences. Neither group improved leg extension power.

CONCLUSION

The addition of lower-limb strength training, using a low-dose approach, to neuromuscular exercise and education carried no additional benefits on self-reported physical function or on most secondary outcomes. Both groups displayed similar improvements at 12-week follow-up. Hence, the current low-dose strength training approach provided no additional clinical value in this group of KOA patients. Trial identifier (ClinicalTrials.gov): NCT03215602.

High and low-load resistance training produce similar effects on bone mineral density of middle-aged and older people: A systematic review with meta-analysis of randomized clinical trials

PURPOSE

To compare the effects of high-load (≥ 70 of 1RM) and low-load (< 70 of 1RM) resistance training (RT) on femoral neck and lumbar spine bone mineral density (BMD) in middle-aged and older people.

DESIGN

Systematic review with meta-analysis.

DATA SOURCE

English language searches of the electronic databases PubMed/Medline, Scopus and Web of Science.

INCLUSION CRITERIA

(i) older or middle-aged (≥ 45 years old) participants of both sexes with or without comorbidities, (ii) studies that compared high-load (≥70% 1 RM) versus low-load (<70% 1RM) RT, (iii) studies that examined femoral neck or lumbar spine BMD.

RESULTS

From 1052 studies found, six were included in qualitative and quantitative analysis. The meta-analysis revealed no difference between groups for femoral neck (weighted mean difference [MD] and 95% confidence interval (CI) = 0.00 g/cm² [95% CI, -0.01 to 0.01]; P = 0.63) and lumbar spine (MD = 0.01 g/cm² [95% CI, -0.00 to 0.02]; P = 0.12) BDM. There was a substantial heterogeneity for femoral neck (I² = 47%; P = 0.07) and lumbar spine (I² = 59%; P = 0.02). Subgroup analysis revealed a significant effect of high-load RT on femoral neck BMD when participants presented normal BMD values (MD = 0.01 g/cm² [95% CI, -0.00 to 0.02]; P = 0.04) and on interventions lasting up to 6 months (MD = 0.01 g/cm² [95% CI, -0.00 to 0.02]; P = 0.03).

CONCLUSION

Both high- and low-load RT have similar effects on femoral neck and lumbar spine BMD in aging people.

Effect of pre-treatment of strength training and raloxifene in periestropause on bone healing

BACKGROUND

There is evidence that strength training (ST) and raloxifene (Ral) treatment during periestropause promotes better bone quality. We wanted to determine whether the skeletal benefits of ST or Ral treatment, performed during periestropause, would persist after fracture. Therefore, the present study aimed to analyze the influence of pre-treatment with ST and administration of Ral during periestropause on bone healing after total unilateral osteotomy.

METHODS

Senescent female Wistar rats between 18 and 21 months of age, performed ST on a ladder three times per week, were administered Ral by gavage (2.3 mg/kg/day), or an association of both. After 120 days, the treatments were interrupted, and a total osteotomy was performed on the left tibia in all animals. They were euthanized 1 and 8 weeks post-osteotomy.

RESULTS

The administration of Ral during periestropause worsened the biochemical and oxidative profile, decreased gene expression of markers related to bone resorption and remodeling, which negatively affected the physicochemical properties; this lead to changes in the bone callus microarchitecture and mass, as well as a decrease in callus resistance to torsional deformation, resulting in lower tissue quality during bone healing. In contrast, ST performed prior to the osteotomy resulted in better bone healing, improvement of the biochemical and oxidative profile, alteration of the genetic profile in favor of bone formation and resorption, as well as the physic-ochemical properties of the callus. These changes led to better microarchitecture and bone mass and increased callus resistance to torsional deformation, confirming its beneficial effect on the quality of bone tissue, providing acceleration of bone consolidation. The combination of therapies at this exercise intensity and drug dosage showed a negative interaction, where the negative effect of Ral overcame the positive effect of ST, leading to decreased tissue quality in the bone healing process.

CONCLUSIONS

This study indicates that in addition to excellent non-pharmacological therapy and action in the prevention of osteoporosis, ST performed during the aging period may increase bone quality at the onset of healing and provide improved bone consolidation. Furthermore, the anti-osteoclastogenic effect of Ral shown in this model delayed the bone repair process, resulting in considerable clinical concern.