Concurrent strength and endurance training exercise sequence does not affect neuromuscular adaptations in older men

Aging Skeletal Muscles: What Are the Mechanisms of Age-Related Loss of Strength and Muscle Mass, and Can We Impede Its Development and Progression?

As we age, we lose muscle strength and power, a condition commonly referred to as sarcopenia (ICD-10-CM code (M62.84)). The prevalence of sarcopenia is about 5-10% of the elderly population, resulting in varying degrees of disability. In this review we emphasise that sarcopenia does not occur suddenly. It is an aging-induced deterioration that occurs over time and is only recognised as a disease when it manifests clinically in the 6th-7th decade of life. Evidence from animal studies, elite athletes and longitudinal population studies all confirms that the underlying process has been ongoing for decades once sarcopenia has manifested. We present hypotheses about the mechanism(s) underlying this process and their supporting evidence. We briefly review various proposals to impede sarcopenia, including cell therapy, reducing senescent cells and their secretome, utilising targets revealed by the skeletal muscle secretome, and muscle innervation. We conclude that although there are potential candidates and ongoing preclinical and clinical trials with drug treatments, the only evidence-based intervention today for humans is exercise. We present different exercise programmes and discuss to what extent the interindividual susceptibility to developing sarcopenia is due to our genetic predisposition or lifestyle factors.

Effect of Strength and Endurance Training Sequence on Endurance Performance

This review investigates the effect of two different concurrent training sequences on endurance performance. The sequences investigated are Endurance-Resistance (ER) and Resistance-Endurance (RE). A literature search is conducted of the SPORTDiscus and Medline databases. The included studies are randomized control trials, which compare the effect of ER and RE on at least one endurance performance variable. A PEDro scale is used to assess the methodological quality of the articles in this review. Of a total of 152 articles identified during the initial screening, 15 studies meet the inclusion criteria. These studies include 426 participants (298 males and 128 females), with 212 of the participants training with ER and 214 with RE. The results are presented as the percentage change of the mean from pre- to post-test. All the studies show an improvement in endurance from pre to post for both interventions, except for the RE group in one study. This review finds small and non-conclusive sequence effects between ER and RE, suggesting that the sequence of concurrent training is not of great importance in relation to endurance performance.

Land- and water-based aerobic exercise program on health-related outcomes in breast cancer survivors (WaterMama): study protocol for a randomized clinical trial

BACKGROUND

Breast cancer is a prevalent form of cancer among women worldwide, often accompanied by physical and psychological side effects due to the disease and the treatment's aggressiveness. Regular physical exercise has emerged as a non-pharmacological approach to improve the quality of life of breast cancer survivors. We herein report the protocol of the WaterMama Study, which aims to evaluate the effects of land- or water-based aerobic exercise programs, compared to a health education program, on cancer-related fatigue and other health-related outcomes in breast cancer survivors.

METHODS

The WaterMama trial is a randomized, single-blinded, three-arm, parallel, superiority trial. We aim to recruit 48 women ≥ 18 years of age who have completed primary treatment for stage I-III breast cancer. Participants are randomly allocated in a 1:1:1 ratio to 12-week interventions of aerobic exercise training programs either in the aquatic or land environment (two weekly 45-min sessions) plus health education (a weekly 45-min session), or an active-control group receiving health education alone (a weekly 45-min session). The primary outcome is cancer-related fatigue, and the secondary outcomes include cardiorespiratory fitness, muscular performance, muscle morphology, functional capacity, mental health, cognitive function, pain, and quality of life. Outcomes assessments are conducted before and after the 12-week intervention period. The analysis plan will employ an intention-to-treat approach and per protocol criteria.

DISCUSSION

Our conceptual hypothesis is that both aerobic exercise programs will positively impact primary and secondary outcomes compared to the health education group alone. Additionally, due to its multi-component nature, we expect the aquatic exercise program promote more significant effects than the land exercise program on cancer-related fatigue, muscular outcomes, and pain.

TRIAL REGISTRATION

The study was prospectively registered at ClinicalTrials.gov NCT05520515. Registered on August 26, 2022. https://clinicaltrials.gov/ct2/show/NCT05520515.

Non invasive techniques for direct muscle quality assessment after exercise intervention in older adults: a systematic review

BACKGROUND

The aging process induces neural and morphological changes in the human musculoskeletal system, leading to a decline in muscle mass, strength and quality. These alterations, coupled with shifts in muscle metabolism, underscore the essential role of physical exercise in maintaining and improving muscle quality in older adults. Muscle quality's morphological domain encompasses direct assessments of muscle microscopic and macroscopic aspects of muscle architecture and composition. Various tools exist to estimate muscle quality, each with specific technical requirements. However, due to the heterogeneity in both the studied population and study methodologies, there is a gap in the establishment of reference standards to determine which are the non-invasive and direct tools to assess muscle quality after exercise interventions. Therefore, the purpose of this review is to obtain an overview of the non-invasive tools used to measure muscle quality directly after exercise interventions in healthy older adults, as well as to assess the effects of exercise on muscle quality.

MAIN TEXT

To address the imperative of understanding and optimizing muscle quality in aging individuals, this review provides an overview of non-invasive tools employed to measure muscle quality directly after exercise interventions in healthy older adults, along with an assessment of the effects of exercise on muscle quality.

RESULTS

Thirty four studies were included. Several methods of direct muscle quality assessment were identified. Notably, 2 studies harnessed CT, 20 utilized US, 9 employed MRI, 2 opted for TMG, 2 adopted myotonometry, and 1 incorporated BIA, with several studies employing multiple tests. Exploring interventions, 26 studies focus on resistance exercise, 4 on aerobic training, and 5 on concurrent training.

CONCLUSIONS

There is significant diversity in the methods of direct assessment of muscle quality, mainly using ultrasound and magnetic resonance imaging; and a consistent positive trend in exercise interventions, indicating their efficacy in improving or preserving muscle quality. However, the lack of standardized assessment criteria poses a challenge given the diversity within the studied population and variations in methodologies.. These data emphasize the need to standardize assessment criteria and underscore the potential benefits of exercise interventions aimed at optimizing muscle quality.

Home-based resistance training performed at either fast or slow speeds improves power output in older adults

PURPOSE

We investigated the effect of an unsupervised, body mass- home-based resistance training program in older adults performed at either a fast or slow contractile speed on changes to muscle-power, -volume, -architecture, and fatigue resistance of the knee extensors.

METHODS

Thirty-two male older adults (age 65-88 years) were separated into 1) fast-speed exercise (Fast-group), 2) slow-speed exercise (Slow-group), and 3) no exercise (Control-group) groups. Participants in the exercise groups performed 30-45 repetitions of knee-extension and sit-to-stand exercises 3 times a week for 8 weeks with different exercise speed between the groups. Before and after the intervention period, the following variables were measured: Isotonic power, isometric strength, twitch contractile properties, muscle-activity, -architecture, and -quality, neuromuscular fatigue resistance of the knee extensors, and thigh muscle volume.

RESULTS

Peak power was increased in both the Fast-group (+24 %, P < 0.01, d = 0.65) and Slow-group (+12 %, P < 0.05, d = 0.33) but not in the Control-group. Training increased pennation angle of the vastus lateralis in both the Fast-group (+8 %, P < 0.01, d = 0.42) and Slow-group (+8 %, P < 0.01, d = 0.42), while only the Fast-group showed increase in pennation angle of the rectus femoris (+12 %, P < 0.01, d = 0.64) and thigh muscle volume (+16 %, P < 0.01, d = 0.52). There was no time × group interaction effect for the other neuromuscular measures.

CONCLUSIONS

Unsupervised, body mass- and home-based resistance training performed at either fast or slow speeds can improve muscle power in older adults, while fast-speed exercise may be preferable over slow-speed owing to the relatively greater improvement of muscle-power, -volume, -architecture, and better time efficiency.

Exploring the Relationship between Ultrasonographic Measures of the Quadriceps and Knee Extensor Muscle Fitness in Endurance-Trained Individuals

Background

B-mode ultrasonography is an accessible and cost-effective method to assess muscle size and quality through muscle thickness (MT) and echo intensity (EI), respectively. Muscle thickness and EI have demonstrated relationships with maximal strength and local muscle endurance, providing a noninvasive and efficient modality to examine muscle fitness. However, these relationships have not been quantified in the individual quadriceps muscles of habitually endurance-trained populations, which may provide information to practitioners regarding rehabilitation and performance.

Methods

Twenty-three participants (males: N = 10; females: N = 13) underwent B-mode ultrasonography to assess MT, EI, and adipose tissue thickness-corrected echo intensity (cEI) in the vastus intermedius (VI), vastus lateralis (VL), and rectus femoris (RF). Muscle fitness was evaluated through maximal strength (1RM) and local muscle endurance (4 sets to failure at 50% 1RM) during dynamic knee extension. Relationships between ultrasonography outcomes and muscle fitness were examined through stepwise multiple linear regression.

Results

The results indicate that VI cEI is the strongest predictor of 1RM strength (r = -0.643), while no ultrasonography-derived measures significantly predicted local muscle endurance.

Conclusion

The study demonstrates that ultrasonography, specifically measures of cEI in the VI, has the greatest association with maximal strength in endurance-trained individuals. These findings suggest monitoring VI muscle size and quality may benefit practitioners who aim to improve knee extension strength for performance or following injury. In addition, the findings support the use of EI examinations in trained populations.

The physiological and physical benefits of two types of concurrent training: a randomized controlled trial

BACKGROUND

It is widely acknowledged that aerobic exercise and strength training are crucial components of most workout programs. However, there is no consensus as to whether the effectiveness of exercises is affected by the sequence in which they are performed. Therefore, the overarching aim of the study was to understand the optimal order of two types of concurrent training program for 13 weeks by comparing the effectiveness of the training on body composition, predicated maximal oxygen uptake (VO2max), dynamic respiratory parameters and muscle strength in healthy middle-aged people.

METHODS

Thirty-three middle-aged individuals, who were categorized as moderately active based on their responses to International Physical Activity Questionnaires, underwent random allocation. The participants were randomly assigned into two groups: the Strength Training followed by Aerobic Training group (SAG, n = 16) and the Aerobic Training followed by Strength Training group (ASG, n = 17). Body composition, aerobic endurance, respiratory parameters, and upper and lower strength were assessed at baseline and after (post-test) a 13-week intervention. The chi-square test and the independent t-test were used to compare sociodemographic variables between the groups. A 2 × 2 analysis of variance (ANOVA) with repeated measures (group x measurement) was conducted. The study was retrospectively registered on clinicaltrials.gov in May of 2023 (clinicaltials.gov identifier: NCT05862415; in 04/25/2023).

RESULTS

Findings showed no significant differences between the group in the VO2max, FVC or FEV1 (F = 1.122, 0.028, 0.06, 2.483; p > 0.05, respectively). Intragroup analysis revealed changes in PEF compared to baseline in the ASG (F = 5.895; p < 0.05). Increases were observed in all strength parameters for both training programs.

CONCLUSIONS

The concurrent training effect on muscle composition, oxygen consumption and muscle strength specifically 1RM, in middle-aged individuals are equivocal, regardless of the exercise order. The results indicate that both exercise sequences can elicit similar benefits in terms of cardiovascular fitness, muscular strength, and endurance. This lack of difference suggests that the order of exercise does not play a significant role in determining the effectiveness of the workout or the subsequent physiological adaptations. CLINICALTIALS.

GOV IDENTIFIER

NCT05862415. Date of registration: 04/25/2023.

Multicomponent Training and Optimal Dosing Strategies for Adults with Hypertension: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

(1) Background: Non-pharmacological interventions have demonstrated efficacy in the prevention, management, and control of hypertension. Multicomponent training confers a host of benefits to the general populace. The aim of this research was to assess the impact of multicomponent training on the blood pressure of adults with hypertension and ascertain the nature of the dose-response relationship. (2) Methods: This systematic review adhered to the PRISMA guidelines and was registered in PROSPERO. Eight studies were included, following a literature search across PubMed, Web of Science, Cochrane, and EBSCO. Randomized controlled trials implementing multicomponent training interventions on adults with hypertension were considered for inclusion. A quality assessment was performed using the PEDro scale, with a random-effects model utilized for all analyses. (3) Results: Multicomponent training yielded a significant reduction in systolic (MD = -10.40, p < 0.001) and diastolic (MD = -5.97, p < 0.001) blood pressure relative to the control group. Interventions lasting over 14 weeks with a minimum frequency of three sessions per week, each lasting 60 min, were deemed most effective. (4) Conclusion: An optimal training intensity was achieved with 30 min of aerobic exercise at 75% of the heart rate reserve, whereas sets of 10 repetitions at 75% of one repetition maximum produced the best outcomes in strength training.

Effects of Exercise Training on Muscle Quality in Older Individuals: A Systematic Scoping Review with Meta-Analyses

BACKGROUND

The quantity and quality of skeletal muscle are important determinants of daily function and metabolic health. Various forms of physical exercise can improve muscle function, but this effect can be inconsistent and has not been systematically examined across the health-neurological disease continuum. The purpose of this systematic scoping review with meta-analyses was to determine the effects and potential moderators of exercise training on morphological and neuromuscular muscle quality (MMQ, NMQ) in healthy older individuals. In addition and in the form of a scoping review, we examined the effects of exercise training on NMQ and MMQ in individuals with neurological conditions.

METHODS

A systematic literature search was performed in the electronic databases Medline, Embase, and Web of Science. Randomized controlled trials were included that examined the effects of exercise training on muscle quality (MQ) in older individuals with and without neurological conditions. Risk of bias and study quality were assessed (Cochrane Risk of Bias Tool 2.0). We performed random-effects models using robust variance estimation and tested moderators using the approximate Hotelling-Zhang test.

RESULTS

Thirty studies (n = 1494, 34% females) in healthy older individuals and no studies in individuals with neurological conditions were eligible for inclusion. Exercise training had small effects on MMQ (g = 0.21, 95% confidence interval [CI]: 0.03-0.40, p = 0.029). Heterogeneity was low (median I² = 16%). Training and demographic variables did not moderate the effects of exercise on MMQ. There was no association between changes in MMQ and changes in functional outcomes. Exercise training improved NMQ (g = 0.68, 95% CI 0.35-1.01, p < 0.000) across all studies, in particular in higher-functioning older individuals (g = 0.72, 95% CI 0.38-1.06, p < 0.001), in lower extremity muscles (g = 0.74, 95% CI 0.35-1.13, p = 0.001), and after resistance training (g = 0.91; 95% CI 0.42-1.41, p = 0.001). Heterogeneity was very high (median I² = 79%). Of the training and demographic variables, only resistance training moderated the exercise-effects on NMQ. High- versus low-intensity exercise moderated the exercise-effects on NMQ, but these effects were considered unreliable due to a low number of studies at high intensity. There was no association between changes in NMQ and changes in functional outcomes.

CONCLUSION

Exercise training has small effects on MMQ and medium-large effects on NMQ in healthy older individuals. There was no association between improvements in MQ and increases in muscle strength, mobility, and balance. Information on dose-response relations following training is currently lacking. There is a critical gap in muscle quality data for older individuals with lower function and neurological conditions after exercise training. Health practitioners should use resistance training to improve muscle function in older individuals. Well-designed studies are needed to examine the relevance of exercise training-induced changes in MQ in daily function in older individuals, especially to those with lower function and neurological conditions.

Do Intramuscular Temperature and Fascicle Angle Affect Ultrasound Echo Intensity Values?

PURPOSE

Ultrasound-derived echo intensity (EI) has been used as a physiological marker for changes in skeletal muscle "quality" with physical training, disuse, aging, and neuromuscular disorders. However, the methodological and physiological factors influencing EI and its longitudinal change are still unclear. Here, we performed two separate experiments to investigate the effects of muscle temperature and fascicle angle, which are known to influence muscle tissue and sound wave properties and therefore affect EI.

METHODS

In experiment 1 ( n = 16, 28.0 ± 6.6 yr), vastus lateralis (VL) ultrasonographic images were acquired and intramuscular temperature continuously recorded for 15 min after 20 min of heating to 40.4°C ± 0.7°C using a microwave device. In experiment 2 ( n = 17, 30.2 ± 9.8 yr), VL sonographic images were obtained with the knee both fully extended (0°) and flexed to 90° and EI and fascicle angle measured post hoc . Fascicle movement was tracked during the passive knee flexion to ensure that sonographic images were obtained at the same muscle region. Knee flexion reduced muscle thickness, and we therefore reran analyses calculating EI using identical dimensions to minimize this effect.

RESULTS

EI decreased only immediately after the passive heating, and although a moderate, negative correlation was observed between EI and temperature ( rrm = -0.36), the effect of muscle temperature was small ( β = 0.97 (-1.89 to -0.06) per degree Celsius, P = 0.051). Nonetheless, EI increased as fascicle angle decreased, and a large, negative correlation ( rrm = -0.85) was observed; the effect of fascicle angle on EI was large ( β = 3.0 (-3.8 to -2.2) per degree, P < 0.01), and this was maintained when analyses were performed at a constant depth of the region of interest ( β = 3.5 (-4.4 to -2.7) per degree, P < 0.01).

CONCLUSIONS

These findings support the hypothesis that fascicle angle meaningfully affects VL EI but provides weak evidence of a temperature effect in vivo . Thus, acute fascicle angle alterations should be accounted for in studies using EI measurements, and longer-term studies should consider whether changes in EI might be partly explained by a change in fascicle angle.

Effect of High-Intensity Interval Treadmill Exercise on Subsequent Lower and Upper Limb Strength Performance

Purpose: The aim of this study was to analyze the acute effect of a treadmill high-intensity interval protocol on subsequent upper body and lower body strength exercise performance. Method: Sixteen young men had their maximal aerobic capacity and one-repetition maximum (1RM) determined and underwent four randomized conditions: a half-squat control session; a bench press control session; a treadmill interval protocol followed by a half-squat experimental session; and a treadmill interval protocol followed by a bench press experimental session. During the control sessions, four sets to failure for each exercise were performed at 80% of 1RM. In the experimental sessions, participants performed eight sprints of 40 s at 100% velocity of maximal oxygen uptake with 20 s of passive interval between them, followed by the same strength exercise protocol of the control sessions. The number of repetitions during each protocol and participants' heart rate (HR),and blood lactate concentration ([lac]) were compared pre and post protocols and exercises. Results: Fewer repetitions were completed in the experimental session compared to the control sessions (p < .001). Moreover, the reduction in number of repetitions performed was more evident in half-squat compared to bench press (p = .018). HR was higher at the end of sessions with the interval protocol for both exercises (p < .001). The [lac] was higher at the end of session with the interval protocol for half-squat (p = .003). Conclusions: These findings suggest that previous high-intensity interval running may impair subsequent strength exercise performance, but the magnitude of the negative effect is greater in the lower limbs.

Combined training prescriptions for improving cardiorespiratory fitness, physical fitness, body composition, and cardiometabolic risk factors in older adults: Systematic review and meta-analysis of controlled trials

Background

Improved physical fitness is important for preventing COVID-19-related mortality. So, combined training can effectively increase peak oxygen consumption, physical fitness, body composition, blood pressure, and the healthrelated characteristics of adults; however, its impact in the elderly remains unclear.

Methods

This systematic review and meta-analysis aimed to evaluate the effects of combined training on older adults. Four electronic databases (PubMed, Scopus, Medline, and Web of Science) were searched (until April 2021) for randomized trials comparing the effect of combined training on cardiorespiratory fitness, physical fitness, body composition, blood pressure, and cardiometabolic risk factors in older adults.

Results

Combined training significantly improved peak oxygen consumption compared to no exercise (WMD = 3.10, 95% CI: 2.83 to 3.37). Combined resistance and aerobic training induced favorable changes in physical fitness (timed up-and-go = -1.06, 30-s chair stand = 3.85, sit and reach = 4.43, 6-minute walking test = 39.22, arm curl = 4.60, grip strength = 3.65, 10-m walk = -0.47, maximum walking speed = 0.15, one-leg balance = 2.71), body composition (fat mass = -2.91, body fat% = -2.31, body mass index = -0.87, waist circumference = -2.91), blood pressure (systolic blood pressure = -8.11, diastolic blood pressure = -4.55), and cardiometabolic risk factors (glucose = -0.53, HOMA-IR = -0.14, high-density lipoprotein = 2.32, total cholesterol = -5.32) in older individuals. Finally, the optimal exercise prescription was ≥ 30 min/session × 50-80% VO2peak, ≥ 3 times/week for ≥ 12 weeks and resistance intensity 70-75% one-repetition maximum, 8-12 repetitions × 3 sets.

Conclusions

Combined training improved VO2peak and some cardiometabolic risk factors in older populations. The dose-effect relationship varied between different parameters. Exercise prescriptions must be formulated considering individual needs during exercise.

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.

Exercise volume load in women with breast cancer: Study protocol for the ABRACE randomized clinical trial

Background

An increased number of breast cancer patients are challenged by acute and persistent treatment side effects. Oncology guidelines have been establishing physical exercise to counteract several treatment-related toxicities throughout cancer care. However, evidence regarding the optimal dose-response, feasibility, and the minimal resistance exercise volume and/or intensity remains unclear. The ABRACE Study will assess the impact of different resistance training volumes (i.e., single or multiple sets) combined with aerobic exercise on physical and psychological outcomes of breast cancer patients undergoing primary treatment.

Methods

This study is a randomized, controlled, three-armed parallel trial. A total of 84 participants, aged ≥18 years, with breast cancer stages I-III, initiating adjuvant or neoadjuvant chemotherapy (≤50% of sessions completed) will be randomized to multiple sets resistance training plus aerobic training group, single set resistance training plus aerobic training group or control group. Neuromuscular and cancer-related fatigue (primary outcomes), muscle strength, muscle thickness, muscle quality by echo intensity, body composition, cardiorespiratory capacity, functional performance, upper-body endurance and quality of life will be measured before and after the 12-week intervention. Our analysis will follow the intention-to-treat approach and per-protocol criteria, with additional sub-group analysis.

Discussion

Findings support prescribing exercise during chemotherapy for breast cancer and elucidate the potential role of different resistance training volumes as a management strategy for physical and psychological impairments in women with early-stage breast cancer. Our main hypothesis is for superiority in physical and psychological outcomes for both training groups compared to the control group, with no difference between single or multiple sets groups.

Trial registration

Clinical trials NCT03314168.

Effects of concurrent training sequence on VO2max and lower limb strength performance: A systematic review and meta-analysis

The aim of this study is to compare the effects of concurrent strength and endurance training sequences on VO_2max and lower limb strength performance to provide scientific guidance for training practice. We searched PubMed, EBSCO, Web of Science (WOS), Wanfang, and China National Knowledge Infrastructure (CNKI) databases up to December 2022. The included articles were randomized controlled trials that allowed us to compare the strength-endurance (S-E) sequence and endurance-strength (E-S) sequence on VO_2max, maximum knee extension strength, maximum knee flexion strength, and lower limb power. The Cochrane bias risk tool was used to evaluate the methodological quality of the included literature, and Stata 12.0 was used for the heterogeneity test, subgroup analysis, draw forest map, sensitivity analysis, and publication bias evaluation. The results have been presented as standardized mean differences (SMDs) between treatments with 95% confidence intervals and calculations performed using random effects models. Significance was accepted when p < 0.05. The studies included 19 randomized controlled trials (285 males and 197 females), 242 subjects in S-E sequence, and 240 subjects in E-S sequence in the analyses. No difference changes between S-E and E-S sequences has been observed on VO_2max in the overall analysis (SMD = 0.02, 95% CI: -0.21-0.25, p = 0.859). The S-E sequence shows a greater increase in lower limb strength performance than does the E-S sequence (SMD = 0.19, 95% CI: 0.02-0.37, p = 0.032), which was manifested in the elderly (p = 0.039) and women (p = 0.017); in training periods >8 weeks (p = 0.002) and training frequencies twice a week (p = 0.003); and with maximum knee flexion (p = 0.040) and knee extension strength (p = 0.026), while no difference was found in lower limb power (p = 0.523). In conclusion, the effect of VO_2max will not change with different concurrent training sequences. The S-E sequence improves lower limb strength more significantly, mainly in the improvement of knee flexion and knee extension. This advantage is more related to factors such as age, gender, training period, and training frequency.

Interindividual variability of adaptations following either traditional strength or power training combined to endurance training in older men: A secondary analysis of a randomized clinical trial

This study aimed to investigate the interindividual responses following two different concurrent training (CT) regimens in neuromuscular, cardiorespiratory and functional outcomes of older men. Thirty-five older men (65.8 ± 3.9 years) were randomly allocated into one of two CT groups: power training (PT) + high-intensity interval training (HIIT) (n = 17); or traditional strength training (TST) + HIIT (n = 18). Maximal dynamic strength (one-repetition maximum, 1RM), rate of force development at 100 milliseconds (RDF₁₀₀), countermovement jump power (CMJ), quadriceps femoris muscle thickness (QF MT), functional tests (sit-to-stand, timed-up-and-go, and stair climbing), and peak oxygen consumption (VO_2peak) were assessed pre-, post-8 and post-16 weeks of training. The Chi-squared test was used for assessing differences in the prevalence of responders (Rs), non-responders (NRs), and adverse responders (ARs). Similar prevalence of individual responses (Rs, NRs and ARs) between groups were observed after intervention in almost all outcomes: 1RM; power at CMJ; QF MT, and functional tests (P > 0.05). However, a significant difference in the distribution of Rs, NRs and ARs between groups was observed in the RFD₁₀₀ after 16 weeks (p = 0.003), with PT + HIIT group presenting high prevalence of Rs than TST + HIIT (100 % vs. 50 %). The inclusion of explosive-type of contractions in a concurrent training regime induces greater responsiveness in the RFD₁₀₀ in older men, while no differences compared to traditional strength training are observed in maximal strength, muscle size, VO_2peak, and functional performance.

Can supplemental protein to low-protein containing meals superimpose on resistance-training muscle adaptations in older adults? A randomized clinical trial

PURPOSE

To evaluate the effects of supplementing protein to the low-protein containing meals on selected parameters of muscle mass, strength, and functional capacity in older individuals undergoing resistance training.

METHODS

Thirty-one male and female older individuals (60 to 80 years) were randomized into either a whey protein/WP (n = 15, 20 g at breakfast + 20 g at dinner) or placebo-maltodextrin/PL (n = 16, 20 g at breakfast + 20 g at dinner) group. Both groups underwent a supervised, progressive resistance training (2×/week) program for 12 weeks. Maximal isometric voluntary contraction (MIVC) of knee extensors, muscle thickness (MT) of knee extensors and elbow flexors, rectus femoris muscle quality (MQ), body composition (as measured by DXA) and functional capacity [as measured by 30-s sit-to-stand (30ss) and timed-up-and-go tests (TUG)] were evaluated at baseline and after the 12-week intervention.

RESULTS

Knee extensor MIVC (WP ∆ = 11.9 ± 11.4% and PL ∆ = 12.9 ± 9.9%) was significantly increased over time, with no between-group differences (all p < 0.05 for main effect of time). Upper- and lower-limb MT were significantly increased over time, with no effect of supplementation (WP: ∆ = 7.0 ± 7.3%, PL: ∆ = 9.5 ± 10.3%; and WP: ∆ = 4.5 ± 5.8%, PL: ∆ = 14.7 ± 28.9%, respectively; all p = 0.001 for main effect of time, respectively). Total and upper-limb lean mass were significantly increased, irrespective of the dietary intervention (WP: ∆ = 0.2 ± 6.3%, PL: ∆ = 1.8 ± 2.9%; and WP: ∆ = 0.10 ± 0.03%, PL: ∆ = 0.15 ± 0.02%, respectively; all p < 0.05 for main effect of time). Main effects of time (all p < 0.05) were also found for 30SS and TUG (fast and usual speeds) (WP: ∆ = 18.2 ± 34.4%, PL: ∆ = 10.4 ± 16.9%; WP: ∆ = 5.4 ± 6.7%, PL: ∆ = 0.7 ± 6.0% and WP: ∆ = 3.3 ± 6.1%, PL: ∆ = 2.3 ± 5.2%, respectively).

CONCLUSION

Supplementing additional whey protein to the lowest-protein containing meals (i.e., ~20 g at breakfast and ~20 g at dinner, daily) did not further augment resistance training-induced neuromuscular adaptations (i.e. muscle strength and mass) in healthy older individuals.

Morphological and Functional Characteristics of the Peroneus Muscles in Patients with Lateral Ankle Sprain: An Ultrasound-Based Study

Background and Objectives: The effectiveness of multiple ultrasound evaluations of the peroneus muscles morphology, including muscle cross-sectional area (CSA) and connective tissue, after lateral ankle sprain (LAS) is unknown. This study aimed to measure the peroneus muscles after LAS at three points, adding distal 75% to the conventional measurement points, in order to obtain a detailed understanding of the post-injury morphology and to propose a new evaluation index of the peroneus muscles for multiple LAS. Materials and Methods: Participants with and without LAS (LAS and control groups, 16 each) were recruited. The muscle cross-sectional area (CSA) and muscle echogenicity were measured using a B-mode ultrasound system at 25%, 50%, and 75% proximal to the line connecting the fibular head to the lateral malleolus. The ankle evertor strength was measured using a handheld dynamometer. Simultaneously, the peroneus longus (PL) and peroneus brevis (PB) muscle activities were measured using surface electromyography. Measurements for the LAS side, non-LAS side, and control leg were performed separately. Results: The CSA was significantly higher at 75% on the LAS side than on the non-LAS side and in the control leg. Muscle echogenicity of the LAS side at 75% was significantly lower than that of the non-LAS side and the control leg. Muscle activity of the PL was significantly lower and the PB was higher on the LAS side than on the non-LAS side and in the control leg. Conclusions: The PL was less active than the PB, while the PB was found to be overactive, suggesting that PB hypertrophy occurs due to an increase in the percentage of muscle fibers and a decrease in the connective tissue. Therefore, it is necessary to evaluate the condition of the PL and PB separately after LAS.

Exercise effects on muscle quality in older adults: a systematic review and meta-analysis

To systematically review and analyse the effects of exercise on morphological and neuromuscular muscle quality (MQ) outcomes in older adults and assess a range of possible moderators that may affect the impact of exercise on MQ outcomes. Using PRISMA guidelines, randomised controlled trials were searched in CINAHL, EMBASE, LILACS, PubMed, SciELO, Web of Science, MedNar, OpenGrey and OpenThesis databases. Eligible trials examined the effects of exercise interventions on morphological and neuromuscular MQ in older adults (≥ 60 years). Twenty-one trials (n = 973 participants) were included. Exercise significantly improved morphological MQ (effect size (ES) = 0.32, 95% CI 0.13–0.51, P < 0.001) with significant results maintained for studies assessing muscle density and intermuscular adipose tissue (ES = 0.45–0.52, P < 0.05). For neuromuscular MQ, exercise provided significant positive effects (ES = 0.49, 95% CI 0.29–0.69, P < 0.001) but only maintained for physically healthy participants (ES = 0.43, P < 0.001), resistance exercise interventions (ES = 0.64, P < 0.001), or studies assessing 1-RM or knee extensor isokinetic muscle strength relative to leg lean mass (ES = 0.48–0.62, P = 0.001). Associations between exercise duration and changes in MQ measures were not observed (P > 0.05). Supervised exercise interventions significantly improved different measures of MQ regardless of exercise duration, although these effects were small-to-moderate and not supported across all population-, exercise-, and methods-related features.

The Effects of Two Different Concurrent Training Configurations on Markers of Metabolic Syndrome and Fitness in Women With Severe/Morbid Obesity: A Randomised Controlled Trial

Concurrent training (CT), characterised by combining both aerobic and resistance training modalities within the same session, is recognised to improve metabolic syndrome (MetS) markers, but little is known about the effects of different configurations (i.e., order) of these exercise modalities on MetS markers and the interindividual responses. The purpose of the present study was to describe the effects, and the interindividual variability, of 20weeks of two CT configurations (i.e., high intensity interval training (HIIT) plus resistance training (RT), compared with RT plus HIIT) in women with severe/morbid obesity. Overall, 26 women with severe/morbid obesity were assigned either to HIIT+RT [n=14, mean and 95%CI, 45.79 (40.74; 50.83) or RT+HIIT (n=12), 33.6 (25.30; 41.79) years]. MetS-related outcomes were waist circumference (WC, cm), systolic (SBP, mmHg) and diastolic (DBP, mmHg) blood pressure, high-density lipoprotein cholesterol (HDL-c), triglycerides (Tg), and fasting plasma glucose (FPG). Secondary outcomes were other anthropometrics, body composition, lipids, muscle strength, and the six-minute walk test (6Mwt). There were significant differences in the prevalence of nonresponders (NRs) only for WC comparing HIIT+RT 2 (18.1%) vs. RT+HIIT group 5 (50.0%), p<0.0001, but not for SBP 4 (27.2%) vs. 4 (40.0%), DBP 8 (72.7%) vs. 7 (70.0%), FPG 8 (72.7%) vs. 9 (90.0%), HDL-c 7 (63.6%) vs. 8 (80.0%), and Tg 7 (63.6%) vs. 8 (80.0%), all p>0.05. Additionally, the RT+HIIT group showed significant reductions in WC (∆ –3.84cm, p=0.015), SBP (∆ –8.46mmHg, p=0.040), whereas the HIIT+RT group elicited significant reductions only in SBP (∆ –8.43mmHg, p=0.022). The HIIT+RT promoted a lower prevalence of NRs than the RT+HIIT configuration on WC, and overall, there were slightly more beneficial training-induced effects on markers of MetS in the RT+HIIT group compared to the HIIT+RT group.

Evaluation of rehabilitation exercise effects by using gradation-based skeletal muscle echo intensity in older individuals: a one-group before-and-after trial study

Background

Higher muscle echo intensity (EI) reflects higher content of fat and/or connective tissue within skeletal muscle, eventually inducing lower muscle strength, physical dysfunction, and metabolic impairment. Continuous exercise decreases muscle EI in older individuals; however, it is not well understood how several months’ rehabilitation exercise affects gradation-based EI. The purpose of this study was to investigate the effects of 6 months of rehabilitation exercise on gradation-based higher and lower EI in older men and women.

Methods

Twenty-seven men and women (7 men, 20 women; age, 75.6 ± 6.4 years; height, 154.3 ± 8.5 cm; weight, 55.8 ± 9.7 kg) participated in this study. This study was a one-group before-and-after trial. They needed long-term care for activities of daily living. They performed rehabilitation exercises consisting of resistance exercises using a hydraulic resistance machine, stretching, and aerobic exercises using a recumbent bicycle once or twice a week for 6 months. B-mode ultrasonographic transverse image was taken from thigh muscles, e.g., rectus femoris, vastus lateralis, and biceps femoris. We calculated gradation-based cross-sectional area (CSA) from thigh muscles by dividing 256 greyscale level to 10 different components levels (e.g., 0–24, 25–49, 50–74, …, 200–224 and 225–249 a.u.).

Results

Lowest EI (e.g., 0–24 a.u.) CSA of thigh muscle was significantly increased after the exercise (0.3 ± 0.3 to 1.0 ± 0.8 cm²; P < 0.05). Middle to higher EI (e.g., 50–74, 75–99, 100–124, 125–149, 150–174, 175–199 and 200–224 a.u.) CSAs were significantly decreased from 23.0 to 68.7% after the exercise (P < 0.05).

Conclusions

Several months’ rehabilitation exercise affected both lower and higher EI in older men and women. This result suggests that rehabilitation exercise changes muscle composition by increasing contractile muscle tissue and decreasing fat and connective tissues.

Effects of high-intensity interval training combined with traditional strength or power training on functionality and physical fitness in healthy older men: A randomized controlled trial

Concurrent training (CT) is an efficient strategy to improve neuromuscular function and cardiorespiratory fitness in older adults, which are factors of pivotal importance for the maintenance of functional capacity with aging. However, there is a lack of evidence about the effectiveness of power training (PT) as an alternative to traditional strength training (TST) during CT. Thus, the aim of the present study was to examine the effect of 16 weeks (twice weekly) TST combined with high intensity interval training (TST + HIIT) vs. PT combined with HIIT (PT + HIIT) on functional performance, cardiorespiratory fitness and body composition in older men. Thirty five older men (65.8 ± 3.9 years) were randomly allocated into two training groups: TST + HIIT (n = 18), and PT + HIIT (n = 17). TST + HIIT performed resistance training at intensities ranging from 65% to 80% 1RM at slow controlled speed (≅ 2 s for each concentric phase), whereas PT + HIIT trained at intensities ranging from 40% to 60% of 1RM at maximal intentional speed. Both groups performed HIIT at intensities ranging from 75 to 90% of VO_2peak. Participants performed functional tests (sit-to-stand, timed-up-and-go, stair climbing); cardiopulmonary exercise testing (maximal cycling power output: W_max, peak oxygen uptake: VO_2peak, cycling economy), as well as body composition assessment (DXA) before, post 8 and post 16 weeks of training. The groups improved similarly (P < 0.05) with training in all functional capacity outcomes, W_max, cycling economy, VO_2peak and body composition (P < 0.05). These findings suggest that HIIT based CT programs involving TST vs. PT are equally effective in improving functionality, cardiorespiratory fitness and body composition in healthy older men.

Exercise rescues mitochondrial coupling in aged skeletal muscle: a comparison of different modalities in preventing sarcopenia

Skeletal muscle aging is associated with a decline in motor function and loss of muscle mass- a condition known as sarcopenia. The underlying mechanisms that drive this pathology are associated with a failure in energy generation in skeletal muscle, either from age-related decline in mitochondrial function, or from disuse. To an extent, lifelong exercise is efficacious in preserving the energetic properties of skeletal muscle and thus may delay the onset of sarcopenia. This review discusses the cellular and molecular changes in skeletal muscle mitochondria during the aging process and how different exercise modalities work to reverse these changes. A key factor that will be described is the efficiency of mitochondrial coupling—ATP production relative to O₂ uptake in myocytes and how that efficiency is a main driver for age-associated decline in skeletal muscle function. With that, we postulate the most effective exercise modality and protocol for reversing the molecular hallmarks of skeletal muscle aging and staving off sarcopenia. Two other concepts pertinent to mitochondrial efficiency in exercise-trained skeletal muscle will be integrated in this review, including- mitophagy, the removal of dysfunctional mitochondrial via autophagy, as well as the implications of muscle fiber type changes with sarcopenia on mitochondrial function.

Age-Related Change in Muscle Characteristics and Resistance Training for Older Adults

In older adults, muscle weakness contributes greatly to functional restrictions on daily living activities, increased risk of falls, and adverse physiological changes. It has been suggested that not only muscle mass but also muscular infiltration of noncontractile elements may influence muscular performance such as strength and rapid force production. It is proved that resistance training may provoke substantial increases in muscle size even if it is performed at low intensities in older individuals. Also, recent studies have demonstrated the effectiveness of resistance training on muscle quality such as muscular infiltration of noncontractile elements for older people. This review shows the age-related changes in muscle mass and muscle quality, which were measured by muscle echo intensity on ultrasound images, and low-intensity resistance training effects on muscle volume and muscle quality.

Exercise associated or not to the intake of Eurycoma longifolia improves strength and cardiorespiratory fitness in men with androgen deficiency

This study aims to analyze the effects of a concurrent training (CT) associated with Eurycoma longifolia (EL) supplementation on the muscle strength, cardiorespiratory fitness, and symptomatology score of men with the androgen deficiency of aging male (ADAM). Forty-five subjects (47.6 ± 5.2 years) were included in the study. The randomized, double-blinded, placebo controlled clinical trial lasted for 6 months. Participants were randomized into four groups, control (C; n = 12); EL (n = 11); CT (n = 11); and CT + EL (n = 11). Along this period, the isokinetic peak torque of the knee extensors increased in the CT (14%) and CT + EL (17%) groups (p = 0.040; p = 0.006, respectively), while the isokinetic peak torque of knee flexion increased in the CT + EL group only (p < 0.05). For all participants, testosterone levels were correlated with isokinetic peak torque of knee extension (r = 0.517, p = 0.001) and flexion (r = 0.362, p = 0.028). Subjects of the CT (27.3%) and CT + EL (36.1%) groups decreased the symptomatology of ADAM (p = 0.005). This study demonstrated the benefits of CT and EL consumption as a non-pharmacological treatment for ADAM.

Echo intensity as an indicator of skeletal muscle quality: applications, methodology, and future directions

PURPOSE

This narrative review provides an overview of the current knowledge of B-mode ultrasound-derived echo intensity (EI) as an indicator of skeletal muscle quality.

METHOD

PubMed and Google Scholar were used to search the literature. Advanced search functions were used to find original studies with the terms 'echo intensity' and/or 'muscle quality' in the title and/or abstract. Publications that conceptually described muscle quality but did not include measurement of EI were not a focus of the review.

RESULT

Importantly, the foundational premise of EI remains unclear. While it is likely that EI reflects intramuscular adiposity, data suggesting that these measurements are influenced by fibrous tissue is limited to diseased muscle and animal models. EI appears to show particular promise in studying muscular aging. Studies have consistently reported an association between EI and muscle function, though not all chronic interventions have demonstrated improvements. Based on the existing literature, it is unclear if EI can be used as a marker of muscle glycogen following exercise and nutritional interventions, or if EI is influenced by hydration status. Inconsistent methodological approaches used across laboratories have made comparing EI studies challenging. Image depth, rest duration, participant positioning, probe tilt, and the decision to correct for subcutaneous adipose tissue thickness are all critical considerations when interpreting the literature and planning studies.

CONCLUSION

While some areas show conflicting evidence, EI shows promise as a novel tool for studying muscle quality. Collaborative efforts focused on methodology are necessary to enhance the consistency and quality of the EI literature.

The Impact of Ultrasound Probe Tilt on Muscle Thickness and Echo-Intensity: A Cross-Sectional Study

INTRODUCTION/BACKGROUND

To determine the influence of ultrasound probe tilt on reliability and overall changes in muscle thickness and echo-intensity.

MATERIALS AND METHODS

Thirty-six individuals had a total of 15 images taken on both the biceps brachii and tibialis anterior muscles. These images were taken in 2° increments with the probe tilted either upward (U) or downward (D) from perpendicular (0°) to the muscle (U6°, U4°, U2°, 0°, D2°, D4°, and D6°). All images were then saved, stored, and analyzed using Image-J software for echo-intensity and muscle thickness measures. Mean values (2-3 measurements within each probe angle) were compared across each probe angle, and reliability was assessed as if the first measure was taken perpendicular to the muscle, but the second measure was taken with the probe tilted to a different angle (to assume unintentional adjustments in reliability from probe tilt).

RESULTS

Tilting the probe as little as 2° produced a significant 4.7%, and 10.5% decrease in echo-intensity of the tibialis anterior and biceps brachii muscles, respectively, while changes in muscle thickness were negligible (<1%) at all probe angles. The reliability for muscle thickness was greater than that of echo-intensity when the probe was held perpendicular at both measurements (∼1% vs 3%), and the impact that probe tilt had on reliability was exacerbated for echo-intensity measurements (max coefficient of variation: 24.5%) compared to muscle thickness (max coefficient of variation: 1.5%).

CONCLUSION

While muscle thickness is less sensitive to ultrasound probe tilt, caution should be taken to ensure minimal probe tilt is present when taking echo-intensity measurements as this will alter mean values and reduce reliability. Echo-intensity values should be interpreted cautiously, particularly when comparing values across technicians/studies where greater alterations in probe tilt is likely.

Effects of long-term concurrent training to failure or not in muscle power output, muscle quality and cardiometabolic risk factors in older men: A secondary analysis of a randomized clinical trial

This study investigated the effects of concurrent training performed either with repetitions to failure or not to failure in muscle power, muscle quality (MQ), peak oxygen uptake (VO_2peak), and visceral fat in older men. This is an ancillary analysis of a randomized controlled trial. 36 older men (mean age ± SD; 67.1 ± 5.1 years) were randomized into three groups: one performing repetitions to failure (RFG, n = 13), another performing repetitions not to failure and 50% of the repetitions of the RFG (NFG, n = 12), and third performing repetitions not to failure with equal training volume of the RFG (ENFG, n = 11). The training was performed twice a week for 20 weeks at intensities ranging from 65 to 80% of maximal strength. In each session, the individuals started with strengthening exercises and then performed aerobic exercise (i.e., walking) on a treadmill. The primary endpoint was change from baseline to post-20 wk of absolute and relative muscle power output during squat and countermovement jump, ultrasound measurements for MQ using quadriceps echo intensity, and visceral fat thickness, as well as their VO_2peak through a maximal incremental test on a treadmill. All training groups improved similarly and significantly jump height (ranging from 9 to 16%) and all their muscle power outcomes (mean change ranging from 2 to 7%) (P < .001). In addition, all groups significantly decreased visceral fat thickness (ranging from -11 to -21%) (P < .001), and significantly increased VO_2peak (ranging from 4 to 8%) (P < .01), with no differences between groups. No changes were observed in the MQ outcomes. Concurrent training performed using repetitions to failure or not to failure promoted similar gains in the muscle power output, aerobic capacity, and visceral fat in healthy older men.

Effects of an 8-week resistance training intervention on plantar flexor muscle quality and functional capacity in older women: A randomised controlled trial

The present study examined 8 weeks of resistance training and its effects on muscle quality measures, plantar flexor muscle strength, muscle thickness and functional capacity in older women. Moreover, we tested if changes in muscle quality were associated with functional capacity. Twenty-four older women (66.3 ± 5.8 years; 69.0 ± 3.0 kg; 25.3 ± 1.4 kg·m^-2) were recruited to the study. After completion of the baseline assessment, participants were randomly assigned to either the resistance training (RET, n = 12) or an active control group (CTR, n = 12). Muscle quality was evaluated through muscle echo intensity (MQ_EI) and specific tension (MQ_ST). Muscle thickness, unilateral plantar flexor muscle strength and functional tests were evaluated at baseline and after the training period. After 8 weeks, both MQ_EI and MQ_ST did not respond to the intervention. Furthermore, significant changes in stair climb performance (P < 0.05) were not associated with plantar flexor-derived muscle quality (P > 0.05). Finally, significant gains in muscle hypertrophy were observed in the RET group (P < 0.01), while muscle strength failed to change significantly (P > 0.05). In conclusion, a resistance training program provided significant benefits in the stair climb test, unrelated to plantar flexor-derived muscle quality measures as previously demonstrated in quadriceps femoris.

Order of same-day concurrent training influences some indices of power development, but not strength, lean mass, or aerobic fitness in healthy, moderately-active men after 9 weeks of training

Background

The importance of concurrent exercise order for improving endurance and resistance adaptations remains unclear, particularly when sessions are performed a few hours apart. We investigated the effects of concurrent training (in alternate orders, separated by ~3 hours) on endurance and resistance training adaptations, compared to resistance-only training.

Materials and methods

Twenty-nine healthy, moderately-active men (mean ± SD; age 24.5 ± 4.7 y; body mass 74.9 ± 10.8 kg; height 179.7 ± 6.5 cm) performed either resistance-only training (RT, n = 9), or same-day concurrent training whereby high-intensity interval training was performed either 3 hours before (HIIT+RT, n = 10) or after resistance training (RT+HIIT, n = 10), for 3 d^.wk^-1 over 9 weeks. Training-induced changes in leg press 1-repetition maximal (1-RM) strength, countermovement jump (CMJ) performance, body composition, peak oxygen uptake (V˙O2peak), aerobic power (W˙peak), and lactate threshold (W˙LT) were assessed before, and after both 5 and 9 weeks of training.

Results

After 9 weeks, all training groups increased leg press 1-RM (~24–28%) and total lean mass (~3-4%), with no clear differences between groups. Both concurrent groups elicited similar small-to-moderate improvements in all markers of aerobic fitness (V˙O2peak ~8–9%; W˙LT ~16-20%; W˙peak ~14-15%). RT improved CMJ displacement (mean ± SD, 5.3 ± 6.3%), velocity (2.2 ± 2.7%), force (absolute: 10.1 ± 10.1%), and power (absolute: 9.8 ± 7.6%; relative: 6.0 ± 6.6%). HIIT+RT elicited comparable improvements in CMJ velocity only (2.2 ± 2.7%). Compared to RT, RT+HIIT attenuated CMJ displacement (mean difference ± 90%CI, -5.1 ± 4.3%), force (absolute: -8.2 ± 7.1%) and power (absolute: -6.0 ± 4.7%). Only RT+HIIT reduced absolute fat mass (mean ± SD, -11.0 ± 11.7%).

Conclusions

In moderately-active males, concurrent training, regardless of the exercise order, presents a viable strategy to improve lower-body maximal strength and total lean mass comparably to resistance-only training, whilst also improving indices of aerobic fitness. However, improvements in CMJ displacement, force, and power were attenuated when RT was performed before HIIT, and as such, exercise order may be an important consideration when designing training programs in which the goal is to improve lower-body power.

Adaptations in mechanical muscle function, muscle morphology, and aerobic power to high-intensity endurance training combined with either traditional or power strength training in older adults: a randomized clinical trial

PURPOSE

There is a lack of information on the effects of power training (PT) as an alternative to traditional strength training (TST) during concurrent training (CT) in older individuals. This study aimed to verify the neuromuscular adaptations that occurred following 16-week interventions with two CT models in older men: high-intensity interval training (HIIT) combined with either TST or PT.

METHODS

Thirty-five older men (65.8 ± 3.9 years) were randomly assigned into one of two training groups CTS: TST + HIIT (n = 18) or CTP: PT + HIIT (n = 17). CTS performed resistance training at intensities ranging from 65 to 80% of 1 RM at slow controlled speed, whereas CTP trained at intensities ranging from 40 to 60% of 1 RM at maximal intentional speed. Lower body one-repetition maximum (1 RM), isometric rate of force development (RFD), countermovement jump (CMJ) muscle power output, quadriceps femoris muscles thickness (QF MT), and peak oxygen uptake (VO_2peak) were assessed before training and after 8 and 16 weeks of CT.

RESULTS

Groups improved similarly in all primary outcomes (P < 0.05), with mean increases ranging: 1 RM (from 39.4 to 75.8%); RFD (from 9.9 to 64.8%); and CMJ muscle power (from 1.8 to 5.2%). Significant increases (P < 0.05) were observed in all secondary outcomes (QF MT, specific tension and VO_2peak) with no differences between groups.

CONCLUSION

CT models were effective for improving maximal and explosive force (1 RM, RFD, and CMJ power), QF MT, and VO_2peak. Moreover, despite that using lower loading intensities, PT induced similar adaptations to those of TST.

Water-based continuous and interval training in older women: Cardiorespiratory and neuromuscular outcomes (WATER study)

The purpose of this study was to investigate the effects of two water-based aerobic programs on cardiorespiratory and neuromuscular outcomes in older women. Forty-one women (60 to 75 years old) volunteered to participate in the study. Participants were randomized into a water-based continuous (CTG; n = 21; 63.9 ± 2.5 years) or an interval (ITG; n = 20; 64.8 ± 3.6 years) aerobic training group. Both training programs were performed for 12 weeks (45-min sessions twice a week), with exercise intensity based on rating of perceived exertion (Borg's RPE 6-20 Scale). Pre and post training assessments of cardiorespiratory and neuromuscular outcomes were performed. Data analyses were conducted using Generalized Estimating Equations and Bonferroni post-hoc test (α = 0.05). After the intervention, the CTG and the ITG displayed similar improvements in time to exhaustion (8% vs. 11%), peak oxygen uptake (9% vs. 7%), maximal dynamic knee extension strength (5% vs. 6%), dynamic muscular endurance of knee extensors (10% vs. 11%), maximal vastus lateralis electromyographic signal amplitude (13% vs. 35%), as well as an increase in muscle thickness (5% vs. 6%) and decrease in muscle echo intensity (-2% vs. -3%) of the quadriceps femoris. In conclusion, older women benefited from water-based exercise training prescribed based on participants' RPE, with both the interval and the continuous training programs resulting in similar increases in the cardiorespiratory and neuromuscular parameters.

The Effects of Concurrent Training Order on Satellite Cell-Related Markers, Body Composition, Muscular and Cardiorespiratory Fitness in Older Men with Sarcopenia

OBJECTIVES

Concurrent Training (CT) is described as a combination of resistance training (RT) and endurance training (ET) in a periodized program to maximize all aspects of physical performance. To date, effects of CT order on muscular and cardiorespiratory fitness adaptations are controversial. Owing to the age-related decrement in satellite cells (SC) which are critical for fiber repair, conservation, muscle hypertrophy as well as cardiorespiratory fitness, the present study examined the response of SC related markers to CT order in older sarcopenic men.

PARTICIPANTS

Thirty older men (age= 64.3 ± 3.5 years) were randomly assigned into one of 3 groups, ET followed by RT (E+R; n=10), RT followed by ET (R+E; n= 10) or a control (C; n=10).

INTERVENTION

The training protocol consisted of 3 exercise sessions per week for 8 weeks. Blood samples were obtained at baseline and 48 hours after the final training session.

RESULTS

Weight, skeletal muscle mass, lower and upper body power, maximal oxygen consumption (VO2max), Paired Box 7 (Pax7), and Myogenic factor 5 (Myf5) significantly increased, while were percent body fat significantly decreased following E+R and R+E compared to C. Importantly, the improvement in skeletal muscle mass, lower and upper body power, Myf5 and Pax7 in the E+R was significantly greater than the R+E group. Myogenin (Myog) and Paired Box 3 (Pax3) significantly increased (P < 0.01) in both training groups compared to no changes in C.

CONCLUSION

An 8-week CT intervention improves SC related markers, body composition and enhances power and VO2max in older sarcopenic participants, regardless of the order of RT and ET. However, performing ET before RT may be more effective at enhancing skeletal muscle mass, Myf5 and Pax7, in addition to both lower and upper body power. While both CT programs produced notable physiological and performance benefits, performing ET before RT during CT may provide the greatest therapeutic benefits for aging individuals.

The effects of same-session combined exercise training on cardiorespiratory and functional fitness in older adults: a systematic review and meta-analysis

Endurance and strength training are effective strategies for counteracting age-associated reductions in physical performance in older adults, with a combination of both exercise modes recommended to maximise potential fitness benefits. This meta-analysis sought to quantify the effects of same-session combined endurance and strength training on fitness in adults aged over 50 years. Five electronic databases were searched with studies required to include one of the following outcome measures: VO_2peak, 6-min walk test (6MWT), 8-ft timed up-and-go (TUG), and 30-s chair stand. Separate random-effects meta-analyses compared combined training with (1) no-exercise control, (2) endurance training, and (3) strength training with probabilistic magnitude-based inferences subsequently applied. Twenty-seven studies involving 1346 subjects with a mean age of 68.8 years (range 54–85 years) were included in the analysis. The meta-analysed effect on VO_2peak was a moderately beneficial effect for the combined training compared to no-exercise controls (3.6 mL kg⁻¹ min⁻¹; ± 95% confidence limits 0.8 mL kg⁻¹ min⁻¹) with additional increases for studies with greater proportions of female participants and shorter training interventions. Combined training also had small-to-moderately beneficial effects on VO_2peak when compared to endurance training (0.8 mL kg⁻¹ min⁻¹; ± 1.0 mL kg⁻¹ min⁻¹), 30-s chair stand when compared with strength training (1.1 repetitions; ± 0.5 repetitions) and on TUG (0.8 s; ± 0.7 s), 30-s chair stand (2.8 repetitions; ± 1.7 repetitions), and 6MWT (31.5 m; ± 22.4 m) when compared to no-exercise controls. All other comparisons were unclear. Same-session combined training can induce clinically relevant fitness improvements in older adults.

Effects of Concurrent Training with Elastic Tubes in Hypertensive Patients: A Blind Controlled Randomized Clinical Trial

BACKGROUND

Concurrent training (CT) has been recommended to minimize the deleterious effects of aging. However, few studies have investigated whether this type of training reduces blood pressure in the elderly. Therefore, our objective was to evaluate the effects of CT on the hemodynamic, cardiorespiratory, and muscle strength responses in medicated hypertensive patients.

METHODS

Twenty-three hypertensives (62.65 ± 6.4 years) of both sexes were allocated to the concurrent training group (CTG) or control group (CG). The CTG performed aerobic training (70-85% of reserve heart rate) combined with resistance training with elastic tubes (2sets × 15 repetitions) for 8 weeks. Resting blood pressure (BP), peak oxygen consumption (VO₂peak), and right knee and elbow flexion strength were evaluated.

RESULTS

A reduction of 6.37% was observed in BP and increases of 16.68% in VO₂peak and 16% in muscle strength for right elbow flexion in the CTG compared to CG (p < .05). Intragroup comparisons showed reduction of 5% for BP, and increases of 6.79% for VO₂peak, 24.79% for elbow flexion, and 16.47% for knee flexion in the CTG (p < .05), without significant improvement in the CG.

CONCLUSION

CT promoted a reduction in BP, and increased cardiorespiratory fitness and muscular strength of the upper limbs in the hypertensive older adults.

CARDIOVASCULAR AND STRENGTH ADAPTATIONS IN CONCURRENT TRAINING IN HYPERTENSIVE WOMEN

ABSTRACT Introduction Physical exercise has been recommended as a non-pharmacological strategy for preventing and controlling hypertension. Objective To verify chronic cardiovascular and muscle strength adaptations in hypertensive women who underwent 12 weeks of concurrent training (CT) in different orders. Methods Twenty hypertensive women were randomly assigned into 2 groups: resistance exercise-endurance group (REE; 56.00 ± 5.20 years; 78.95 ± 8.28 kg; 155.10 ± 5.30 cm; 33.00 ± 5.30 kg.m-2) and endurance-resistance exercise group (ERE; 57.10 ± 13.38 years; 76.56 ± 18.87 kg; 155.50 ± 8.18 cm; 31.41 ± 5.84 kg.m-2). The endurance exercise was composed of 3 sets of 4 exercises, with 8-RM loads with a 90-second break between sets and exercises. The resistance exercise lasted for 25 minutes and was of progressive intensity. Muscle strength (8-RM), systolic and diastolic blood pressure, heart rate, and double product were assessed pre- and post-exercise. Results The ANOVA showed significant increases in strength for all exercises (p <0.0001) regardless of the order of the concurrent training (bench press, p = 0.680; leg press, p = 0.244; seated row, p = 0.668; and leg extension, p = 0.257). No significant differences in systolic (p = 0.074) and diastolic blood pressures (p = 0.064) were observed for different CT conditions. However, significant reductions in systolic (p = 0.0001) and diastolic blood pressures (p = 0.006) and double product (p = 0.006) only occurred in the REE group. Conclusion Endurance training and resistance exercise promote significant muscle strength gains after 12 weeks of training regardless of CT order in hypertensive women. Beneficial cardiovascular responses (SBP, DBP, and RPP) were also observed when endurance training was initiated. Level of evidence I; Therapeutic Studies - Investigating Treatment Outcomes.

The Effects of High- Versus Low-Intensity Power Training on Muscle Power Outcomes in Healthy, Older Adults: A Systematic Review

Power training (PT) improves muscle power in older adults; however, intensity recommendations are less clear. A narrative approach was used to compare high- versus low-intensity PT on muscle power (and function) in healthy, older adults. Searches were performed using Medline, Embase, CINAHL, SPORTDiscus, AgeLine, and Scopus. Interventions in which older subjects (60+ years) were instructed to perform the concentric phase "as fast as possible" were included. After searches were performed, a third category of PT (moderate intensity) was included. Evidence from 27 studies (32 PT groups) showed changes in muscle power that averaged 26.8%, 33.4%, and 21.5% for high-, moderate-, and low-intensity PT, respectively, with greater changes with longer training duration and in mildly mobility-limited older adults. Function improved similarly across categories. In conclusion, both low- and high-intensity PT led to clinically significant changes in power and are viable options for improving power and function in older adults.

Effects of 10-week walking and walking with home-based resistance training on muscle quality, muscle size, and physical functional tests in healthy older individuals

Background

Older individuals have been shown to present muscle atrophy in conjunction with increased fat fraction in some muscles. The proportion of fat and connective tissue within the skeletal muscle can be estimated from axial B-mode ultrasound images using echo intensity (EI). EI was used to calculate the index of muscle quality. Walking, home-based weight-bearing resistance training, and its combinations are considered simple, easy, and practical exercise interventions for older adults. The purpose of this study was to quantify the effects of walking and walking with home-based resistance training on muscle quality of older individuals.

Methods

Thirty-one participants performed walking training only (W-group; 72 ± 5 years) and 33 participants performed walking and home-based resistance training (WR-group; 73 ± 6 years). This study was a non-randomized controlled trial with no control group. All participants were instructed to walk 2 or 3 sets per week for 10 weeks (one set: 30-min continuous walking). In addition, the WR-group performed home-based weight-bearing resistance training. EI was measured as a muscle quality index using axial B-mode ultrasound images of the rectus femoris and vastus lateralis of the mid-thigh. We further averaged these parameters to obtain the EI of the quadriceps femoris (QF). Participants further performed five functional tests: sit-ups, supine up, sit-to-stand, 5-m maximal walk, and 6-min walk.

Results

QF EI was significantly decreased in both groups after training (W-group 69.9 ± 7.4 a.u. to 61.7 ± 7.0 a.u., WR-group 64.0 ± 9.5 a.u. to 51.1 ± 10.0 a.u.; P < 0.05), suggesting improved muscle quality. QF EI was further decreased in the WR-group compared with the W-group. The sit-up test in both groups and the sit-to-stand and 5-m maximal walk tests in the W-group were significantly improved after training.

Conclusion

These results suggest that training-induced stimulation is associated with a decrease in EI in some thigh regions. Furthermore, the addition of home-based resistance training to walking would be effective for a greater reduction of EI.

A Brief Review on Concurrent Training: From Laboratory to the Field

The majority of sports rely on concurrent training (CT; e.g., the simultaneous training of strength and endurance). However, a phenomenon called “Concurrent training effect” (CTE), which is a compromise in adaptation resulting from concurrent training, appears to be mostly affected by the interference of the molecular pathways of the underlying adaptations from each type of training segments. Until now, it seems that the volume, intensity, type, frequency of endurance training, as well as the training history and background strongly affect the CTE. High volume, moderate, continuous and frequent endurance training, are thought to negatively affect the resistance training-induced adaptations, probably by inhibition of the Protein kinase B—mammalian target of rapamycin pathway activation, of the adenosine monophosphate-activated protein kinase (AMPK). In contrast, it seems that short bouts of high-intensity interval training (HIIT) or sprint interval training (SIT) minimize the negative effects of concurrent training. This is particularly the case when HIIT and SIT incorporated in cycling have even lower or even no negative effects, while they provide at least the same metabolic adaptations, probably through the peroxisome proliferator-activated receptor-γ coactivator (PGC-1a) pathway. However, significant questions about the molecular events underlying the CTE remain unanswered.

Comparison of time-matched aerobic, resistance, or concurrent exercise training in older adults

A supervised 12-week intervention of time-matched aerobic vs resistance versus concurrent exercise training was employed to investigate mode- and time course-specific effects of exercise training in older adults. Community-dwelling men and women (n = 84; M/F, 45/39; 69.3 ± 3.5 years; 26.4 ± 3.8 kg m^-2 ) were randomly assigned (n = 21 each) to either non-exercise control (CON), aerobic exercise only (AER), resistance exercise only (RES), or concurrent aerobic and resistance exercise (CEX). Training groups trained three times per week, each performing 72 minutes of active exercise time per week. Body composition, physical and cognitive function, and markers of metabolic health were assessed before (PRE), and after 6 (MID) and 12 (POST) weeks of exercise training. Hand-grip strength, 1RM chest press, and arm LBM were improved by both RES and CEX, but not AER. Aerobic fitness increased in AER and RES, but not CEX. Cognitive function improved in all groups, but occurred earlier (ie, at MID) in AER. CEX improved gait speed and lower limb strength and reduced trunk fat compared to either AER or RES. Leg LBM was unchanged in any group. Temporal patterns were observed as early as 6 weeks of training (gait speed, upper and lower limb strength, aerobic fitness), whereas others were unchanged until 12 weeks (hand-grip strength, timed up-and-go, sit-to-stand). Compared to either aerobic or resistance exercise training alone, concurrent exercise training is as efficacious for improving a range of health-related parameters and is more efficacious for increasing gait speed and lower limb strength, and decreasing trunk fat in older adults.