Selection of Resistance Exercises for Older Individuals: The Forgotten Variable

Effect of trunk posture on external and internal oblique muscles' activities during forced expiration

INTRODUCTION

The activities of external oblique (EO) and internal oblique (IO) muscles during forced expiration in a trunk-neutral posture are insufficient for muscle strengthening. Furthermore, these activities during forced expiration may be affected by trunk postures, which can change respiratory muscle activity. Therefore, this study aimed to evaluate the effects of trunk posture on the EO and IO muscles' activities during forced expiration.

METHODS

Thirty healthy males participated in this study. The participants were placed in the supine position with their trunks in the neutral, right rotation, or right lateral trunk flexion position, and their bilateral EO and IO muscles' activities during forced expiration were measured using surface electromyography.

RESULTS

The right EO muscle's activity during forced expiration was significantly higher in the right trunk flexion position than in the neutral trunk and right trunk rotation positions (p < 0.05 and p < 0.001, respectively) but was significantly lower in the right trunk rotation than in the neutral trunk (p < 0.01). In contrast, the left EO muscle's activity was significantly higher in the right trunk rotation position than in the neutral trunk and right lateral trunk flexion positions (p < 0.001 for both) but was significantly lower in the right lateral trunk flexion position than in the neutral trunk position (p < 0.01). The bilateral IO muscles' activity during forced expiration did not significantly differ among the three postures.

CONCLUSION

The findings indicated that the bilateral EO muscles' activity during forced expiration was affected by trunk posture.

Movement pattern definitions for resistance training behavior measurement in diabetes

Type 2 diabetes can result in debilitating vascular complications, and resistance training (RT) is an effective therapy for improving cardiovascular outcomes. However, only 10-30% of adults meet the public health guidance for RT. While current RT guidelines focus on targeting major muscle groups, guidance specific to simplified movement categorization may augment understanding of RT programming and improve uptake and outcomes. Current movement pattern definitions and descriptions lack clarity, accuracy, and consistency. This paper proposes movement definitions and descriptions to be used for RT intervention design and prescription, and includes the following categories: hip, knee, ankle, vertebral column, vertical push, horizontal push, vertical pull, and horizontal pull. These categories are intended to aid clinicians, researchers, and trainers in RT surveillance and RT intervention design for improving vascular complications in type 2 diabetes. Simplified RT program design using these categories may also facilitate greater RT program understanding and adherence for patients.

The REtirement in ACTion exercise programme and its effects on elements of long term functionality in older adults

Background

The prevention of mobility-related disability amongst adults is a global healthcare priority. Cost-effective community-based strategies to improve physical function and independence in older adults with mobility limitations are needed. This study investigated the effectiveness of the REtirement in ACTion (REACT) exercise intervention on individual markers of physical function at 6-and 12-months.

Methods

The REACT multicentre randomised controlled trial assigned 777 older adults (female, 514; male 263) (mean age 77·6 [SD 6·8] years) with reduced lower limb physical functioning (Short Physical Performance Battery [SPPB] score 4-9) to receive brief healthy ageing advice or a 12-month, group-based, multimodal exercise programme delivered in local communities. Estimated differences in the three individual component scores of the SPPB (strength, balance, gait speed) and physical functional outcomes recorded at 6- and 12-months were assessed.

Results

The intervention group demonstrated significant improvements in strength (OR = 1.88, 95% CI = 1.36-2.59, p < 0.001) and balance (OR = 1.96, 95% CI = 1.39-2.67, p < 0.001) at 12-months, but not in gait speed (OR = 1.32, 95% CI = 0.91-1.90, p = 0.139). In comparison to the control group, at six-and 12-months, the intervention group reported statistically significant improvements in Mobility Assessment Tool-Short Form (MAT-SF), physical component score from SF-36 questionnaire, and strength and endurance items of subjectively reported physical activity (PASE 10-item). Greater than 75% adherence (attending ≥48 of the 64 exercise sessions delivered in 12-months) was associated with superior functional outcomes.

Conclusion

The REACT exercise programme provides local, regional and national service providers with an effective solution to increase muscle strength and balance in older adults at risk of mobility disability.

Active Gains in brain Using Exercise During Aging (AGUEDA): protocol for a randomized controlled trial

Alzheimer's disease is currently the leading cause of dementia and one of the most expensive, lethal and severe diseases worldwide. Age-related decline in executive function is widespread and plays a key role in subsequent dementia risk. Physical exercise has been proposed as one of the leading non-pharmaceutical approaches to improve executive function and ameliorate cognitive decline. This single-site, two-arm, single-blinded, randomized controlled trial (RCT) will include 90 cognitively normal older adults, aged 65-80 years old. Participants will be randomized to a 24-week resistance exercise program (3 sessions/week, 60 min/session, n = 45), or a wait-list control group (n = 45) which will be asked to maintain their usual lifestyle. All study outcomes will be assessed at baseline and at 24-weeks after the exercise program, with a subset of selected outcomes assessed at 12-weeks. The primary outcome will be indicated by the change in an executive function composite score assessed with a comprehensive neuropsychological battery and the National Institutes of Health Toolbox Cognition Battery. Secondary outcomes will include changes in brain structure and function and amyloid deposition, other cognitive outcomes, and changes in molecular biomarkers assessed in blood, saliva, and fecal samples, physical function, muscular strength, body composition, mental health, and psychosocial parameters. We expect that the resistance exercise program will have positive effects on executive function and related brain structure and function, and will help to understand the molecular, structural, functional, and psychosocial mechanisms involved.

Characteristics of resistance training-based protocols in older adults with sarcopenic obesity: a scoping review of training procedure recommendations

Background

Sarcopenic obesity (SO) is a clinical and functional disease characterized by the coexistence of obesity and sarcopenia. Resistance training (RT) characteristics for older adults with sarcopenia or obesity are already well established in the scientific literature. Nonetheless, we still do not know how detailed the RT protocols are described for older adults with SO. Therefore, we aimed to analyze the characteristics of RT programs, including each of their variables, recommended for older adults with SO.

Methods

This is a scoping review study that was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis for Scoping Reviews. The search was carried out until November 2022 in PubMed/MEDLINE, EMBASE, Cochrane Library, Web of Science, Scopus, LILACS, Google Scholar, and medRxiv databases. The studies included SO diagnosis and RT as an intervention strategy. The RT variables analyzed were as follows: exercise selection, the volume of sets, the intensity of load, repetition cadence, rest interval between sets, and weekly frequency.

Results

A total of 1,693 studies were identified. After applying the exclusion criteria, 15 studies were included in the final analysis. The duration of the RT intervention ranged from 8 to 24 weeks. All studies included full-body routines, with single/multi-joint exercises. Regarding the volume of sets, some studies fixed it in three sets, whereas others varied between one and three sets. The load was reported by repetition range and the weight lifted, elastic-band color/resistance, percentage of one repetition maximum, or perceived exertion scale. Repetition cadence was fixed in some studies, while it was self-selected between concentric and eccentric phases in others. The interval between sets of rest varied from 30 to 180 s. All studies reported progression overload during the interventions. Not all studies reported how the exercise selection, repetition cadence, and rest interval were made.

Conclusion

The characteristics of RT protocols and their variables prescribed in the literature for older adults with SO were mapped. The lack of detail on some training variables (i.e., exercise selection, repetition cadence, and rest interval) was identified. RT protocols are heterogeneous and described only partially among studies. The recommendations for RT prescription details in older adults with SO are provided for future studies.

Systematic review registration

https://osf.io/wzk3d/.

Resistance Circuit Training or Walking Training: Which Program Improves Muscle Strength and Functional Autonomy More in Older Women?

To evaluate the effects of two programs (resistance and walking training) on the functional autonomy and muscle strength (isometric and dynamic) of older women, 67 subjects were divided randomly into three groups: resistance training (RTG; Mean = 64.70 ± 6.74 years), walking (WG, Mean = 65.56 ± 7.82 years), and control (CG; Mean = 64.81 ± 4.34). The experimental groups underwent a 16-week intervention. Muscle strength (isometric and dynamic) and functional autonomy were assessed. The subjects participating in the RTG showed improvements in the comparison pre to post-test in the maximal forces of upper limb (MULS) (Δ% = 49.48%; p = 0.001) and lower limb (MLLS) (Δ% = 56.70%; p = 0.001), isometric biceps forces (BIS) (Δ% = 30.13%; p = 0.001) and quadriceps forces (QIS) (Δ% = 65.92%; p = 0.001), and in the general index (GI) of functional autonomy (Δ% = −18.32%; p = 0.002). The WG improved in all functional autonomy tests, except for the standing up from prone position test (SVDP). In strength tests, the WG obtained improvements only in the QIS (Δ% = 41.80%; p = 0.001) and MLLS (Δ% = 49.13%; p = 0.001) tests. The RTG obtained better results (p < 0.05) when compared to the WG and CG. The results allow us to infer that resistance exercise programs are more effective in increasing strength and functional autonomy, a fact that may mitigate the deleterious effects on health of aging.

Strength training in elderly: An useful tool against sarcopenia

The loss of muscle mass and strength in elderly population (especially after the age of 65–70) represents a public health problem. Due to the high prevalence of frailty in older adults, cardiovascular or low-intensity exercise is implemented as first choice option. Although beneficial these training schemes are not as effective as strength-based resistance training for increasing muscle strength and hypertrophy. In fact, when performed progressively and under professional supervision, strength-based training has been proposed as an important and valid methodology to reduce sarcopenia-related problems. In this mini-review, we not only summarize the benefits of weight resistance training but also highlight practical recommendations and other non-conventional methods (e.g., suspension training) as part of an integral anti-sarcopenia strategy. Future directions including cluster set configurations and high-speed resistance training are also outlined.

Improving muscle strength and physical function in older people living with sarcopenia and physical frailty: Not all exercise is created equal

Exercise is an increasingly widely used treatment for older people across a range of clinical conditions including sarcopenia and physical frailty. Whilst exercise can have many benefits for older people, adaptations to exercise are specific to the exercise mode that is performed and not all exercise is created equal. The correct type of exercise, at the correct dose, needs to be prescribed to maximise effectiveness in treating sarcopenia and physical frailty where maintaining or improving muscle strength and physical function represent key aims. Resistance exercise (RE) is the most potent approach to improving muscle strength and physical function and should be prioritised within exercise programmes delivered to this group. Resistance exercise programme design should be underpinned by the fundamental principles of exercise prescription in order to deliver an appropriate and individualised exercise dose to maximise the potential of RE as a treatment for older people living with sarcopenia and physical frailty.

The Effects of High-Speed Resistance Training on Health Outcomes in Independent Older Adults: A Systematic Review and Meta-Analysis

Human ageing involves several physiological impairments—in particular, a decrease in sensorimotor function and changes in the nervous system reduce muscle strength, power, balance, and functional capacity performance. Preventive strategies are essential to ensure the quality of life of the elderly. High-speed resistance training (HSRT) may be an effective approach to muscle power development in this population, with significant short-term effects on neural adaptations and muscle power production. Therefore, the present study intends to analyze and systematize the studies focused on HSRT interventions and their effects on health outcomes in independent older adults. Four electronic databases (PubMed, Web of Science, EBSCO, and Scielo) were used for the purposes of searching randomized controlled trials that measured at least one key outcome measure focusing on velocity-based training and health outcomes in older adults on 7 March 2022 and identified 1950 studies. At the end of the process, fourteen studies were included in this systematic review and ten studies were included in the quantitative analysis. The main results showed that HSRT interventions would improve health measures, mostly cognitive function (large effects, p = 0.001, SMD = 0.94), neuromuscular function (moderate effects, p = 0.003, SMD = 0.70), and physical function (moderate effects, p = 0.04, SMD = 0.55 and p = 0.009, SMD = −0.59). Additionally, the results suggested that interventions with ten weeks or more, performed three times a week, provide significant improvements in neuromuscular function. In this sense, HSRT is effective for improving overall health outcomes in older adults. Future studies should include proper follow-ups (e.g., minimum six months) to assess the durability of HSRT intervention effects on all health-related variables.

Resistance exercise as a treatment for sarcopenia: prescription and delivery

Sarcopenia is a generalised skeletal muscle disorder characterised by reduced muscle strength and mass and associated with a range of negative health outcomes. Currently, resistance exercise (RE) is recommended as the first-line treatment for counteracting the deleterious consequences of sarcopenia in older adults. However, whilst there is considerable evidence demonstrating that RE is an effective intervention for improving muscle strength and function in healthy older adults, much less is known about its benefits in older people living with sarcopenia. Furthermore, evidence for its optimal prescription and delivery is very limited and any potential benefits of RE are unlikely to be realised in the absence of an appropriate exercise dose. We provide a summary of the underlying principles of effective RE prescription (specificity, overload and progression) and discuss the main variables (training frequency, exercise selection, exercise intensity, exercise volume and rest periods) that can be manipulated when designing RE programmes. Following this, we propose that an RE programme that consists of two exercise sessions per week and involves a combination of upper- and lower-body exercises performed with a relatively high degree of effort for 1–3 sets of 6–12 repetitions is appropriate as a treatment for sarcopenia. The principles of RE prescription outlined here and the proposed RE programme presented in this paper provide a useful resource for clinicians and exercise practitioners treating older adults with sarcopenia and will also be of value to researchers for standardising approaches to RE interventions in future sarcopenia studies.

Sagittal spine disposition and pelvic tilt during outdoor fitness equipment use and their associations with kinanthropometry proportions in middle-aged and older adults

BACKGROUND

Outdoor fitness training has become popular as a tool for improving the health, especially middle-aged and older adults. For this purpose, outdoor fitness equipment (OFE) have been installed in public areas. However, their safety and effectiveness are still unknown. The aim of the present research was to analyze the sagittal disposition of the spine and pelvic tilt during the use of OFE, and to determine the influence of anthropometric variables on these factors in middle-aged and older adults.

METHODS

Seventy healthy volunteers, 56 women and 14 men (age: 63.14 ± 8.19 years) participated in the study. Sagittal spine disposition and pelvic tilt were measured using a Spinal Mouse®, in the relaxed standing position, and during the use of the OFE. In addition, kinanthropometry variables were also measured according to the guidelines of the International Society for the Advancement of Kinanthropometry.

RESULTS

Regarding thoracic kyphosis, a significant decrease was found in thoracic kyphosis in the initial position (IP) in single bonny rider (SBR) (p = 0.006) and row (p = 0.046), and a significant increase in the final position (FP) in the row (p = 0.011), surfboard (p < 0.001) and air walker (p = 0.027) machines. In relation to the lumbar curvature and pelvic tilt, a significant decrease in lumbar lordosis and a decrease in pelvic anteversion were observed in the IP and FP in SBR and row; and in the bike (p < 0.001) machine. In the surfboard machine, a significant decrease in lumbar lordosis was found (p = 0.002), with no changes in pelvic tilt. According to the multiple linear regression analysis, the subjects with a higher cormic index and height were more at risk of increasing their thoracic kyphosis, decreasing lumbar lordosis and/or decreasing pelvic anteversion towards pelvic retroversion.

CONCLUSIONS

Middle-aged and older adults show spinal misalignments when using the OFE with respect to the standing position, showing a decrease in the thoracic kyphosis in IP of SBR and ROW, and a significant increase in the surfboard and air walker, and in the FP of Row, in the lumbar lordosis in all the OFE in sitting and some in standing, and in the pelvic anteversion in all the OFE in sitting. The variables height and the cormic index explained most of the changes in sagittal spine disposition.

A Randomized Controlled Feasibility Trial Evaluating a Resistance Training Intervention With Frail Older Adults in Residential Care: The Keeping Active in Residential Elderly Trial

Frailty is associated with negative health outcomes, disability, and mortality. Physical activity is an effective intervention to improve functional health status. However, the effect of resistance training on multidimensional health in frail older adults remains unclear. This randomized controlled trial was conducted in a U.K. residential care home to assess feasibility with limited efficacy testing on health and functional outcomes and to inform a future definitive randomized controlled trial. Eleven frail older adults (>65 years) completed a 6-week machine-based resistance training protocol three times a week. Uptake and retention were greater than 80%. The measures and intervention were found to be acceptable and practicable. The analyses indicated large improvements in functional capacity, frailty, and strength in the intervention group compared with the controls. These findings support the feasibility of a definitive randomized controlled trial and reinforce the value of resistance training in this population. This trial was registered with ClinicalTrials.gov: NCT03141879.

Cross-sectional and longitudinal associations between adherence to Mediterranean diet with physical performance and cognitive function in older adults: A systematic review and meta-analysis

OBJECTIVES

The present study investigated the association between adherence to Mediterranean diet (MeDi) and physical performance and cognitive function in older adults.

METHODS

We conducted a systematic review and meta-analysis of cross-sectional and longitudinal studies that investigated older adults aged 60+ years and assessed adherence to MeDi diet using validated composite scores. Observational studies, including cross-sectional, case-control, and longitudinal cohort studies, if crude baseline data was available, which investigated as a primary or secondary outcome the association of MeDi diet adherence with physical performance and/or cognitive function in non-demented older adults were included in the cross-sectional analysis. For the longitudinal analysis, case-control and longitudinal cohort studies that investigated the longitudinal associations between adherence to MeDi diet with the incidence of mild cognitive impairment (MCI), dementia, and/or Alzheimer's disease (AD), and/or changes in physical performance and cognition in non-demented older adults were included. Studies published in other languages than English were excluded. Studies were retrieved from MEDLINE, SCOPUS, CINAHL, and AgeLine databases until May 19, 2021. The risk of bias was evaluated using the Newcastle - Ottawa Quality Assessment Scale (NOS). A pooled effect size was calculated based on standard mean differences (SMD), log odds ratio (OR) and log risk ratio (RR). This study is registered on PROSPERO (CRD42021250254).

RESULTS

Nineteen cross-sectional studies that investigated 19.734 community-dwelling and institutionalized older adults free of disability and dementia were included. A high adherence to MeDi was cross-sectionally associated with better walking speed (SMD = 0.42; 95 % Confidence Interval (CI) = 0.12-0.72, P = 0.006; I² = 65 %, P = 0.06), knee muscle strength speed (SMD = 0.26; 95 % CI = 0.17-0.36, P < 0.00001; I² = 0 %, P = 0.69), global cognition (SMD = 0.24; 95 % CI = 0.15-0.33, P < 0.00001; I² = 85 %, P < 0.00001), and memory (SMD = 0.18; 95 % CI = 0.13-0.25, P < 0.00001; I² = 100 %, P < 0.00001). The association between MeDi adherence and global cognition remained significant after stratifying the analysis by the region where the study was conducted, MeDi diet adherence composite score, and Mini Mental State Examination (MMSE). Studies had a moderate to low risk of bias. In relation to longitudinal analysis, thirty-four prospective studies with an average follow-up period that varied from 3.0 to 12.6 years and investigated 98.315 community-dwellers were included. Results indicated that older adults with high MeDi scores had a lower decline in global cognition RR = 0.26; 95 % CI = 0.23-0.29, P < 0.00001; I² = 100 %, P < 0.00001). In contrast, no significant associations between MeDi and mobility, MCI, dementia were found. A low risk of bias was found in the longitudinal studies.

DISCUSSION

Findings of the present study indicated that high adherence to MeDi was cross-sectionally associated with physical performance and cognitive function. Results of the pooled analysis of longitudinal studies revealed that high adherence to MeDi reduced the risk of global cognitive decline in non-demented older adults. However, no significant associations between MeDi adherence and the incidence of mobility problems, MCI, and dementia were found. Although important, our findings should be carefully interpreted due to the presence of heterogeneity and publication bias.

Evidence-based recommendations for resistance and power training to prevent frailty in community-dwellers

Frailty is a reversible state of reduced resilience to stressful events resulting from a multisystem impairment of the human body. As frailty progresses, people become more vulnerable to numerous adverse events, including falls and fractures, cognitive decline, disability, hospitalization, nursing home placement, and death. As such, substantial health care costs are associated with frailty. These features have led to the recognition of frailty as a public health problem. The identification of strategies for the management of frailty has, therefore, become a topic of extensive instigation. In this context, resistance (RT) and power training (PT) have received considerable attention, and experts in the field have recently suggested that both training modalities may improve frailty-related parameters. However, most studies have only included robust people and investigated frailty as a secondary outcome, so that current literature only allows RT and PT preventive programs against frailty to be designed. Here, we provide evidence-based critical recommendations for the prescription of RT and PT programs against incident frailty in community-dwellers.

Strength Training to Prevent Falls in Older Adults: A Systematic Review with Meta-Analysis of Randomized Controlled Trials

We performed a systematic review with meta-analysis of randomized controlled trials (RCTs) to assess the effects of strength training (ST), as compared to alternative multimodal or unimodal exercise programs, on the number of falls in older adults (≥60 years). Ten databases were consulted (CINAHL, Cochrane Library, EBSCO, EMBASE, PEDro, PubMed, Scielo, Scopus, SPORTDiscus and Web of Science), without limitations on language or publication date. Eligibility criteria were as follows: RCTs with humans ≥60 years of age of any gender with one group performing supervised ST and a group performing another type of exercise training, reporting data pertaining falls. Certainty of evidence was assessed with Grading of Recommendations, Assessment, Development and Evaluation (GRADE). Meta-analysis used a random effects model to calculate the risk ratio (RR) for number of falls. Five RCTs with six trials were included (n = 543, 76% women). There was no difference between ST and alternative exercise interventions for falls (RR = 1.00, 95% CI 0.77–1.30, p = 0.99). The certainty of evidence was very low. No dose–response relationship could be established. In sum, ST showed comparable RR based on number of falls in older adults when compared to other multimodal or unimodal exercise modalities, but evidence is scarce and heterogeneous, and additional research is required for more robust conclusions. Registration: PROSPERO CRD42020222908.

Low-volume cycling training improves body composition and functionality in older people with multimorbidity: a randomized controlled trial

Physical exercise, when practiced regularly and in adequate doses, is a proven nonpharmacological measure that helps to prevent and reverse noncommunicable diseases, as well as reduce mortality rates from any cause. In general, older adults perform insufficient physical activity and do not meet the doses recommended by the World Health Organization for the improvement of health through physical activity. However, there is little evidence on adequate doses of exercise in older people, especially in those with multimorbidity. Our main aim was to evaluate the effect of a 6-week intervention on health-related outcomes (body composition, hemodynamic and functionality changes) in 24 individuals aged 65 and older with multimorbidity in a randomized controlled trial. The intervention consisted of a very low volume (60 min per week) of low-to-moderate intensity exercise training (perception of effort from 3 to 6 on an 11-point scale). After the intervention, blood pressure was significantly (p = 0.038) reduced in the exercise group (EG), with a higher reduction in men. Furthermore, the EG decreased their waist circumference (p = 0.005), a proxy of abdominal adiposity, and demonstrated an increased likelihood (73%) that a randomly selected change in muscle mass score from the EG would be greater than a randomly selected change score from the control group. The exercise intervention was particularly effective in enhancing the functionality of older adults with multimorbidity, especially in walking speed and balance skills. Perceptually regulated intensity during exercise training seemed to be a very interesting strategy to train individuals with low physical fitness and comorbidities. This study is registered with Clinicaltrials.gov (NCT04842396).

Comparison of traditional and accommodating resistance training with chains on muscular adaptations in young men

BACKGROUND

Providing accommodating resistance with the use of chains (CRT) is a programming technique that may enhance muscle size, strength, and power. However, there is a paucity of studies comparing the responses to CRT and traditional resistance training (TRT) approaches. This study aimed to examine the effects of 8 weeks of CRT and TRT on muscular adaptations in young recreationally-trained men.

METHODS

Thirty men (26 ± 4 y) volunteered to participate in the present study and were randomly assigned to either CRT (n = 10), TRT (n = 10), or a non-exercise control group (CG, n = 10). A resistancetraining program (3-4 sets, ~8-12 repetitions at 65-80% of 1RM) was performed three times a week for 8 weeks. Percentage body fat, arm and thigh circumferences, 1RM and endurance (number of repetitions to failure 60% of 1RM) strength tests in the back squat and bench press exercises, and vertical jump power were assessed before and after the intervention.

RESULTS

Following the intervention, both training groups demonstrated improvements in strength compared to CG, where greater gains were observed for CRT (e.g., bench press 1RM: CRT=28%; TRT=19% / back squat endurance: CRT=8%; TRT=2%).

CONCLUSIONS

The use of chains during resistance training may promote greater gains in strength in young men.

Equating Resistance-Training Volume Between Programs Focused on Muscle Hypertrophy

Calculating resistance-training volume in programs focused on muscle hypertrophy is an attempt to quantify the external workload carried out, then to estimate the dose of stimulus imposed on targeted muscles. The volume is usually expressed in some variables that directly affected the total training work, such as the number of sets, repetitions, and volume-load. These variables are used to try to quantify the training work easily, for the subsequent organization and prescription of training programs. One of the main uses of measures of volume quantification is seen in studies in which the purpose is to compare the effects of different training protocols on muscle growth in a volume-equated format. However, it seems that not all measures of volume are always appropriate for equating training protocols. In the current paper, it is discussed what training volume is and the potentials and shortcomings of each one of the most common ways to equate it between groups depending on the independent variable to be compared (e.g., weekly frequency, intensity of load, and advanced techniques).

Effects of Adding Inter-Set Static Stretching to Flywheel Resistance Training on Flexibility, Muscular Strength, and Regional Hypertrophy in Young Men

Performing static stretching (SS) during resistance training (RT) rest periods is posited to potentiate muscular adaptations, but the literature is scarce on the topic. Thus, the purpose of this study was to investigate the effects of adding inter-set SS to a lower-limb flywheel RT program on joint flexibility, muscular strength, and regional hypertrophy. Sixteen untrained male adults (21 ± 1 y) completed the study, where they performed progressive flywheel bilateral squatting twice a week for 5 weeks. One leg of each participant was randomly allocated to perform SS during the inter-set rest period (RT+SS), while the other leg served as control (RT only). Before and after the intervention, knee flexion range of motion; knee extension isometric, concentric, and eccentric peak torque; 1-repetition maximum; and muscle thickness of the lower-limb muscles were assessed. Following the training period, additional effects were observed for the inter-set SS side on increasing joint flexibility (p < 0.05), whereas the average increase in strength measures was 5.3% for the control side, and 10.1% for the inter-set SS side, however, SS intervention induced significantly greater gains only for knee extension isometric strength, but not for dynamic 1-RM, concentric, and eccentric tests. Hamstrings and gluteus maximus did not hypertrophy with training; increases quadriceps muscle thickness depended on the site/portion analyzed, but no significant difference was observed between legs (average: RT = 7.3%, RT+SS = 8.0%). The results indicate that adding inter-set SS to RT may provide large gains in flexibility, slightly benefits for muscular strength (especially for isometric action), but do not impact muscle hypertrophy in untrained young men.

Placing Greater Torque at Shorter or Longer Muscle Lengths? Effects of Cable vs. Barbell Preacher Curl Training on Muscular Strength and Hypertrophy in Young Adults

Muscular strength and hypertrophy following resistance training may be obtained in different degrees depending on the approach performed. This study was designed to compare the responses of the biceps brachii to two preacher curl exercises, one performed on a cable-pulley system (CAB; in which a greater torque was applied during the exercise when elbows were flexed and biceps shortened) and one performed with a barbell (BAR; in which greater torque was applied when the elbows were extended and biceps stretched). Thirty-five young adults (CAB: 13 men, 5 women; BAR: 12 men, 5 women; age = 24 ± 5 years) performed a resistance training program three times per week for 10 weeks, with preacher curl exercises performed in three sets of 8–12 repetitions. Outcomes measured included elbow flexion peak isokinetic torque at angles of 20°, 60°, and 100° (considering 0° as elbow extended), and biceps brachii thickness (B-mode ultrasound). Following the training period, there were significant increases for both groups in elbow flexion peak torque at the 20° (CAB: 30%; BAR = 39%; p = 0.046), 60° (CAB: 27%; BAR = 32%; p = 0.874), and 100° (CAB: 17%; BAR = 19%; p = 0.728), and biceps brachii thickness (CAB: 7%; BAR = 8%; p = 0.346). In conclusion, gains in muscular strength were greater for BAR only at longer muscle length, whereas hypertrophy was similar regardless of whether torque emphasis was carried out in the final (CAB) or initial (BAR) degrees of the range of motion of the preacher curl in young adults.