Heterogeneity of physical function responses to exercise training in older adults

Responsiveness of functional performance and muscle strength, power, and size to resistance training: A systematic review

There is a recent and growing interest in assessing differential responders to resistance training (RT) for diverse outcomes. Thus, the individual ability to respond to an intervention for a specific measurement, called responsiveness, remains to be better understood. Thus, the current study aimed to summarize the available information about the effects of RT on functional performance and muscle strength, power, and size in healthy adults, through the prevalence rate in different responsiveness classifications models. A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and was registered at the International Prospective Register of Systematic Reviews (PROSPERO, CRD42021265378). PubMed/MEDLINE, Scopus, and Embase databases were systematically searched in October 2023. A total of 13 studies were included, totaling 921 subjects. Only two studies presented a low risk of bias. Regarding the effectiveness of RT, the prevalence rate for non-responders ranged from 0% to 44% for muscle strength, from 0% to 84% for muscle size, and from 0% to 42% for functional performance, while for muscle power, the only study found showed a responsiveness rate of 37%. In conclusion, a wide range of differential responders is described for all variables investigated. However, the evidence summarized in this systematic review suggested some caution while interpreting the findings, since the body of evidence found seems to be incipient, and widely heterogeneous in methodological and statistical aspects.

Understanding the variation in exercise responses to guide personalized physical activity prescriptions

Understanding the factors that contribute to exercise response variation is the first step in achieving the goal of developing personalized exercise prescriptions. This review discusses the key molecular and other mechanistic factors, both extrinsic and intrinsic, that influence exercise responses and health outcomes. Extrinsic characteristics include the timing and dose of exercise, circadian rhythms, sleep habits, dietary interactions, and medication use, whereas intrinsic factors such as sex, age, hormonal status, race/ethnicity, and genetics are also integral. The molecular transducers of exercise (i.e., genomic/epigenomic, proteomic/post-translational, transcriptomic, metabolic/metabolomic, and lipidomic elements) are considered with respect to variability in physiological and health outcomes. Finally, this review highlights the current challenges that impede our ability to develop effective personalized exercise prescriptions. The Molecular Transducers of Physical Activity Consortium (MoTrPAC) aims to fill significant gaps in the understanding of exercise response variability, yet further investigations are needed to address additional health outcomes across all populations.

Serum factors mediate changes in mitochondrial bioenergetics associated with diet and exercise interventions

Mitochondrial improvements resulting from behavioral interventions, such as diet and exercise, are systemic and apparent across multiple tissues. Here, we test the hypothesis that factors present in serum, and therefore circulating throughout the body, can mediate changes in mitochondrial function in response to intervention. To investigate this, we used stored serum from a clinical trial comparing resistance training (RT) and RT plus caloric restriction (RT + CR) to examine effects of blood borne circulating factors on myoblasts in vitro. We report that exposure to dilute serum is sufficient to mediate bioenergetic benefits of these interventions. Additionally, serum-mediated bioenergetic changes can differentiate between interventions, recapitulate sex differences in bioenergetic responses, and is linked to improvements in physical function and inflammation. Using metabolomics, we identified circulating factors associated with changes in mitochondrial bioenergetics and the effects of interventions. This study provides new evidence that circulating factors play a role in the beneficial effects of interventions that improve healthspan among older adults. Understanding the factors that drive improvements in mitochondrial function is a key step towards predicting intervention outcomes and developing strategies to countermand systemic age-related bioenergetic decline.

Translation and Psychometric Properties of the Portuguese Version of the Timed Instrumental Activities of Daily Living (TIADL)

(1) Background: to examine the psychometric properties of the Portuguese version of the Timed Instrumental Activities of Daily Living (TIADL) in nursing home residents. (2) Methods: Fifty-two participants (85.8 ± 4.2 years) were assessed on two occasions, 10-14 days apart. The same rater administered all assessments. Internal consistency was analysed through Cronbach's α. The reliability was estimated using the intraclass correlation coefficients (ICCs), and the standard error of the mean (SEM) was used to estimate the minimal detectable change (MDC). Construct validity was determined by Spearman's correlation coefficients. (3) Results: For internal consistency, Cronbach's α (0.81) revealed high internal reliability. All of the subtests demonstrated good or excellent reliability and also presented acceptable measurement precision, considering the criterion SEM < SD/2. According to Spearman's rho, correlations with the Portuguese version of the TIADL, the Useful Field of View test, and semantic and phonemic fluency tests were significant, with moderate positive and negative correlations (0.4 < rs < 0.69). (4) Conclusions: The Portuguese version of the TIADL had good to excellent test-retest reliability (ICC > 0.90) and acceptable measurement precision. This test could be a valuable clinical tool for assessing actual performance in instrumental activities of daily living in nursing home residents.

The Effects of Power Training Frequency on Muscle Power and Functional Performance in Older Women: A Randomized Controlled Trial

ABSTRACT

Katsoulis, K and Amara, CE. The effects of power training frequency on muscle power and functional performance in older women: a randomized controlled trial. J Strength Cond Res 37(11): 2289-2297, 2023-Low-intensity power training (PT) has emerged as an effective method for improving muscle power and functional performance in older adults. However, effects of low training frequencies are less understood and could expand the repertoire of exercise prescription, particularly in older women who experience greater functional disability with age compared with men. This study investigated the impact of frequency of low-intensity (40% of 1 repetition maximum, 1RM) PT on lower-body power and functional performance in healthy older women. Women (74 ± 4 years) were randomized to 12 weeks of PT of 1 (PT1, n = 14), 2 (PT2, n = 17), or 3 (PT3, n = 17) d·wk -1 or wait control (CON, n = 15). Measures included leg press 1RM, knee extension power (KEP), and functional performance (stair climb power, stair climb time, 30-second chair stands, 400-m walk, Short Physical Performance Battery). There were no differences between the frequency of training in changes in leg press 1RM, KEP, or functional performance after 12 weeks. Pre-post data for individual training groups revealed that leg press 1RM improved in all PT groups (20-33%, p < 0.05). Furthermore, KEP improved in PT2 and PT3 by 10 and 12%, respectively, and all PT groups improved in the 30-second chair stands and Short Physical Performance Battery (6-22%), whereas PT1 and PT3 improved in the 400-m walk and PT2 improved in stair climb power and stair climb time after training (4-7%, p < 0.05). One to 3 weekly low-intensity PT sessions can improve functional performance, although improvements in both functional performance and power might require 2 or 3 sessions per week in older healthy women.

Does Higher Intensity Increase the Rate of Responders to Endurance Training When Total Energy Expenditure Remains Constant? A Randomized Controlled Trial

BACKGROUND

Standardized training prescriptions often result in large variation in training response with a substantial number of individuals that show little or no response at all. The present study examined whether the response in markers of cardiorespiratory fitness (CRF) to moderate intensity endurance training can be elevated by an increase in training intensity.

METHODS

Thirty-one healthy, untrained participants (46 ± 8 years, BMI 25.4 ± 3.3 kg m^-2 and [Formula: see text]O_2max 34 ± 4 mL min^-1 kg^-1) trained for 10 weeks with moderate intensity (3 day week^-1 for 50 min per session at 55% HR_reserve). Hereafter, the allocation into two groups was performed by stratified randomization for age, gender and VO_2max response. CON (continuous moderate intensity) trained for another 16 weeks at moderate intensity, INC (increased intensity) trained energy-equivalent for 8 weeks at 70% HR_reserve and then performed high-intensity interval training (4 × 4) for another 8 weeks. Responders were identified as participants with VO_2max increase above the technical measurement error.

RESULTS

There was a significant difference in [Formula: see text]O_2max response between INC (3.4 ± 2.7 mL kg^-1 min^-1) and CON (0.4 ± 2.9 mL kg^-1 min^-1) after 26 weeks of training (P = 0.020). After 10 weeks of moderate training, in total 16 of 31 participants were classified as VO_2max responders (52%). After another 16 weeks continuous moderate intensity training, no further increase of responders was observed in CON. In contrast, the energy equivalent training with increasing training intensity in INC significantly (P = 0.031) increased the number of responders to 13 of 15 (87%). The energy equivalent higher training intensities increased the rate of responders more effectively than continued moderate training intensities (P = 0.012).

CONCLUSION

High-intensity interval training increases the rate of response in VO_2max to endurance training even when the total energy expenditure is held constant. Maintaining moderate endurance training intensities might not be the best choice to optimize training gains. Trial Registration German Clinical Trials Register, DRKS00031445, Registered 08 March 2023-Retrospectively registered, https://www.drks.de/DRKS00031445.

Patterns of improvement in functional ability and predictors of responders to dual-task exercise: A latent class analysis

Background

Exercise is the pillar for healthy aging. "Non-responders" may be due to a mismatch in exercise prescription. A latent cluster analysis (LCA) profile can be useful to uncover subpopulations sharing similar profiles or outcomes. We aim to use the LCA to develop a response prediction model for older adults who would benefit from The Healthy Aging Promotion Program for You, a community-embedded dual-task exercise program.

Methods

A total of 197 participants completed the 3-month follow-up, and the complete data were available for 136 community-dwelling older adults. Inclusion criteria were age ≥60 years, pre-frail or frail and ambulant, mild cognitive impairment, and ability to provide consent. Data collected include demographics, education, falls, physical function (Katz ADL scale and Lawton's IADL scale), physical activity (rapid assessment of physical activity), cognition (Montreal Cognitive Assessment; MoCA), frailty (FRAIL scale), and perceived health, pain, anxiety/depression, fear of falling, and social isolation (Lubben Social Network Scale). The body mass index (BMI), handgrip strength, and short physical performance battery (SPPB) were measured. Those who improved in frailty, anxiety/depression, pain, Lubben, MoCA, SPPB, fear-of-falling, physical activity, falls, and HGS were classified as responders.

Results

The mean age was 74.7 years, BMI 23.5 kg/m², 23.5% were male, 96.3% were of Chinese ethnicity, 61% were pre-frail, education level of 4.3 years, and the MoCA score of 23.3 ± 4.8. Two clusters were identified: non-responders (61.8%) and responders (38.2%). Responders had significant improvement in cognition (44.2% vs. 0, p < 0.001) and SPPB (gait:28.8% vs. 0, p < 0.001; balance:42.3% vs. 15.5%, p = 0.001; chair-stand:65.4% vs. 4.8%, p < 0.001). Responders were significantly older (76.9 vs. 73.3 years, p = 0.005), had higher BMI (24.8 vs. 22.8 kg/m², p = 0.007), lower education (3.4 vs. 4.9 years, p = 0.021), lower MoCA scores (21.8 vs. 24.3, p = 0.002), and lower SPPB scores (8.7 vs. 10.6, p < 0.001). The predictive variables for the responder cluster were age ≥75 years, BMI ≥23 kg/m², robust, no anxiety, pain, fear of falling, MoCA ≤22, Lubben ≤12, SPPB score: chair-stand ≤2, balance ≤2, gait >2, handgrip strength <20 kg, no falls and RAPA >3. With an optimal cut-off of ≥12, this prediction model had sensitivity of 76.9%, specificity of 70.2%, positive predictive value 61.5%, and negative predictive value of 83.1%.

Conclusion

Response to dual-task exercise was influenced by age, SPPB, BMI, and cognition. Prospective longitudinal studies are needed to validate this LCA model and guide the development of public health strategies.

What is real change in submaximal cardiorespiratory fitness in older adults? Retrospective analysis of a clinical trial

Objective

To assess the test–retest reliability of submaximal cardiorespiratory fitness in healthy active older adults.

Methods

This was a retrospective analysis of 41 adults enrolled in a clinical trial [mean (sd) aged 59 yrs (7); 29% females; and body mass index 24.5 kg/m² (3.3)]. Cardiorespiratory fitness was assessed using a cycle ergometer 6 weeks apart. The initial workload was 1 W per kilogram of free fat mass (W/kg FFM) and increased by 0.5 W/kg FFM every 3 min until participants could not maintain the speed at ≥ 60 rpm, they reached a rating of perceived exertion of 15–17, and/or obtained a respiratory exchange ratio (RER) of 1.000. Reliability of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${V}{\text{O}}_{2}$$\end{document}VO2_, heart rate and RER was assessed for each workload, and for \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${V}{\text{O}}_{2}$$\end{document}VO2_, when RER reached 1.00. Reliability was examined as the intraclass correlation coefficient (ICC_(2,1)), Bland–Altman plots, standard error of measurement (SEM and SEM%), and the minimal detectable change (MDC).

Results

Test–retest agreement ranged between (ICC_(2,1) 0.44–0.84) with no discernible systematic differences between assessments. The SEM% for absolute and relative \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${V}{\text{O}}_{2}$$\end{document}VO2 ranged between 13.0 to 20.2%, and 13.8 to 26.3%, respectively_. The MDC₉₀% for absolute and relative \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${V}{\text{O}}_{2}$$\end{document}VO2 ranged between 30.4% to 47.1%, and 32.2% to 61.4%, respectively. The lowest SEMs% and MDCs% for both absolute and relative \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${V}{\text{O}}_{2}$$\end{document}VO2 were observed for workloads at 2.5 W kg/FFM (~ 13% and ~ 31%, respectively).

Conclusions

Although at least modest relative reliability was consistently demonstrated, the smaller measurement error associated with absolute and relative \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${V}{\text{O}}_{2}$$\end{document}VO2 at 2.5 W kg/FFM may indirectly suggest that submaximal cardiorespiratory fitness can be monitored more confidently at higher workloads. Findings provide critical information to determine how much change is considered ‘real change’ in repeated measures of cardiorespiratory fitness using a submaximal graded exercise testing protocol in healthy active older adults.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40798-022-00447-6.

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

IMPORTANCE

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

OBJECTIVE

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

DATA SOURCES

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

STUDY SELECTION

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

DATA EXTRACTION AND SYNTHESIS

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

MAIN OUTCOMES AND MEASURES

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

RESULTS

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

CONCLUSIONS AND RELEVANCE

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

Skeletal muscle properties show collagen organization and immune cell content are associated with resistance exercise response heterogeneity in older persons

In older individuals, hypertrophy from progressive resistance training (PRT) is compromised in approximately one- third of participants in exercise trials. The objective of this study was to establish novel relationships between baseline muscle features and/or their PRT-induced change in vastus lateralis muscle biopsies with hypertrophy outcomes. Multiple linear regression analyses adjusted for sex were performed on phenotypic data from older adults (n=48, 70.8±4.5 years) completing 14 weeks of PRT. Results show that baseline muscle size associates with growth regardless of hypertrophy outcome measure (fiber cross-sectional area (fCSA), β=-0.76, Adj. p<0.01; thigh muscle area by CT, β=-0.75, Adj. p<0.01; DXA thigh lean mass, β=-0.47, Adj. p<0.05). Furthermore, loosely packed collagen organization (β=-0.44, Adj. p<0.05) and abundance of CD11b+/CD206- immune cells (β=-0.36, Adj. p=0.10) were negatively associated with whole muscle hypertrophy, with a significant sex interaction on the latter. Additionally, a composite hypertrophy score generated using all three measures reinforces significant fiber level findings that changes in myonuclei (β=0.67, Adj. p<0.01), changes in immune cells (β=0.48, Adj. p<0.05; both CD11b+/CD206+ and CD11b+/CD206- cells), and capillary density (β=0.56, Adj. p<0.01) are significantly associated with growth. Exploratory single cell RNA-sequencing of CD11b+ cells in muscle in response to resistance exercise showed that macrophages have a mixed phenotype. Collagen associations with macrophages may be an important aspect in muscle response heterogeneity. Detailed histological phenotyping of muscle combined with multiple measures of growth response to resistance training in older persons identify potential new mechanisms underlying response heterogeneity and possible sex differences.

Heterogeneity in resistance training-induced muscle strength responses is associated with training frequency and insulin resistance in postmenopausal women

BACKGROUND

In older adults, muscle strength (MS), a key component of sarcopenia, is essential to maintaining independence and physical capacity. The rate of muscle strength decline typically accelerates during the menopausal transition. Although MS has been shown to increase with resistance training (RT), the response to training is quite heterogeneous. Thus, if contributing factors to RT non-responsiveness to MS gains are identified, it may be possible to develop more effective and personalized ways to improve MS or identify individuals who may benefit from RT interventions. This study assessed potential factors that may contribute to MS response heterogeneity in postmenopausal women: training frequency, serum FSH and estrogen levels, adiposity, inflammation marker, and insulin resistance.

METHODS

One hundred and thirteen individuals participated in a 16-week program of supervised RT (3 sets, 8-12 repetitions, and 2-3 times/week). A control group (CTL, n = 63 - no performed the RT) was used as the comparator arm. Body composition (skinfold) and blood samples (metabolic and inflammatory indicators and hormones) were measured at baseline. Knee extensor strength (1RM) was measured at baseline, 8 weeks, and 16 weeks.

RESULTS

Only the RT group increased 1RM after 8 weeks (RT = 14 ± 12% vs. CTL = 6 ± 15%). Both groups increased 1RM after 16 weeks, with the RT group showing a greater increase than the CTL group (RT = 31 ± 23% vs CTL = 13 ± 25%). After 8 weeks of RT, 41 (36% of total) individuals were considered non-responders (based on control group responses) and 27 (24% of total) individuals after 16 weeks. At week 8, lower RT frequency (2 times/week vs. 3 times/week) was associated with higher odds of being non-responder (3 times, P = 0.048). At week 16, lower RT frequency (13 times, P = 0.009) and higher HOMA-IR (for every unit increase, odds increase by 40%, P = 0.022) were associated with higher odds of being non-responder. Higher QUICKI was associated with lower odds of being non-responder (for every unit increase, odds decrease by 16%, P = 0.039). Moreover, higher RT frequency (17 times, P = 0.028) and higher QUICKI (for every unit increase, odds increase by 41%, P = 0.017) were associated with higher odds of becoming a responder at week 16, being a non-responder at week 8.

CONCLUSION

Heterogeneity in RT-induced MS responses is associated with training frequency and insulin resistance in postmenopausal women.

The role of right supra-marginal gyrus and secondary somatosensory cortex in age-related differences in human emotional egocentricity

Emotional egocentric bias (EEB) occurs when, due to a partial failure in self-other distinction, empathy for another's emotion is influenced by our own emotional state. Recent studies have revealed a higher EEB in children, adolescents and older adults compared to young adults, but the neural correlates of this finding are largely unknown. We asked female participants (N = 95) from three different age groups (adolescents, young and older adults) to perform a well-validated EEB task in an MRI scanner. We assessed task-based changes in activity and effective connectivity as well as morphometric changes in regions of interest to pinpoint functional and structural age-related differences. Results revealed higher EEB in older compared to young adults and adolescents. Connectivity between right supramarginal gyrus (rSMG) and somatosensory cortices acted as a partial mediator between age and EEB. The findings suggest that an intact connectivity of rSMG, rather than its regional activity, with sensory-perceptual brain areas is crucial for overcoming egocentric biases of empathic judgments.

A Systematic Review Examining the Approaches Used to Estimate Interindividual Differences in Trainability and Classify Individual Responses to Exercise Training

Background: Many reports describe statistical approaches for estimating interindividual differences in trainability and classifying individuals as "responders" or "non-responders." The extent to which studies in the exercise training literature have adopted these statistical approaches remains unclear. Objectives: This systematic review primarily sought to determine the extent to which studies in the exercise training literature have adopted sound statistical approaches for examining individual responses to exercise training. We also (1) investigated the existence of interindividual differences in trainability, and (2) tested the hypothesis that less conservative thresholds inflate response rates compared with thresholds that consider error and a smallest worthwhile change (SWC)/minimum clinically important difference (MCID). Methods: We searched six databases: AMED, CINAHL, EMBASE, Medline, PubMed, and SportDiscus. Our search spanned the aerobic, resistance, and clinical or rehabilitation training literature. Studies were included if they used human participants, employed standardized and supervised exercise training, and either: (1) stated that their exercise training intervention resulted in heterogenous responses, (2) statistically estimated interindividual differences in trainability, and/or (3) classified individual responses. We calculated effect sizes (ES_IR) to examine the presence of interindividual differences in trainability. We also compared response rates (n = 614) across classification approaches that considered neither, one of, or both errors and an SWC or MCID. We then sorted response rates from studies that also reported mean changes and response thresholds (n = 435 response rates) into four quartiles to confirm our ancillary hypothesis that larger mean changes produce larger response rates. Results: Our search revealed 3,404 studies, and 149 were included in our systematic review. Few studies (n = 9) statistically estimated interindividual differences in trainability. The results from these few studies present a mixture of evidence for the presence of interindividual differences in trainability because several ES_IR values lay above, below, or crossed zero. Zero-based thresholds and larger mean changes significantly (both p < 0.01) inflated response rates. Conclusion: Our findings provide evidence demonstrating why future studies should statistically estimate interindividual differences in trainability and consider error and an SWC or MCID when classifying individual responses to exercise training. Systematic Review Registration: [website], identifier [registration number].

Resistance Training with Blood Flow Restriction Compared to Traditional Resistance Training on Strength and Muscle Mass in Non-Active Older Adults: A Systematic Review and Meta-Analysis

Low-intensity training with blood flow restriction (LI-BFR) has been suggested as an alternative to high-intensity resistance training for the improvement of strength and muscle mass, becoming advisable for individuals who cannot assume such a load. The systematic review aimed to determine the effectiveness of the LI-BFR compared to dynamic high-intensity resistance training on strength and muscle mass in non-active older adults. A systematic review was conducted according to the Cochrane Handbook and reportedly followed the PRISMA statement. MEDLINE, EMBASE, Web of Science Core Collection, and Scopus databases were searched between September and October 2020. Two reviewers independently selected the studies, extracted data, assessed the risk of bias and the quality of evidence using the GRADE approach. Twelve studies were included in the qualitative synthesis. Meta-analysis pointed out significant differences in maximal voluntary contraction (MVC): SMD 0.61, 95% CI [0.10, 1.11], p = 0.02, I² 71% p < 0.0001; but not in the repetition maximum (RM): SMD 0.07, 95% CI [−0.25, 0.40], p = 0.66, I² 0% p < 0.53; neither in the muscle mass: SMD 0.62, 95% CI [−0.09, 1.34], p = 0.09, I² 59% p = 0.05. Despite important limitations such as scarce literature regarding LI-BFR in older adults, the small sample size in most studies, the still differences in methodology and poor quality in many of them, this systematic review and meta-analysis revealed a positive benefit in non-active older adults. LI- BFR may induce increased muscular strength and muscle mass, at least at a similar extent to that in the traditional high-intensity resistance training.

Integrating a Prevention Care Path into the Daily Life of Older Adults with Mobility Disability Risk: Introducing a Predictive Response Model to Exercise

Introduction

Exercise and nutrition are the best targets to tackle mobility issues in community-dwelling older adults. As exercise response relies on multiple factors, improving the understanding of their interactions is a necessity to tailor effective preventive strategies. Based on a prevention care path designed for community-dwelling older adults with mobility disability risk, our main goal was to determine the predictive factors of the response to a multimodal intervention, combining structured exercise training and nutritional counselling. Thus, this study aimed to tailor prevention programs for non-responder participants.

Methods

We analyzed the response of participants to a prevention program and built a multivariate predictive model to highlight the profile of the best responders. The model was based on the likelihood of at least 1 point of short physical performance battery (SPPB) score gain. Inclusion criteria were being aged ≥70 years and having completed a multicomponent group-based supervised training consisting of 20 sessions (10 weeks).

Results

A total of 103 participants were included, their mean ± SD age was 81.9 ± 5.7 years. The model demonstrated interactions between baseline SPPB score (OR=0.42; p < 0.001), body mass index (BMI; OR=0.82; p=0.003), and grip strength value (OR=1.15; p=0.008). The highest probability of response was found for participants with low SPPB, normal BMI (21 kg/m²), and high grip strength (27 kg).

Conclusion

This study demonstrated that the response to a multimodal intervention in community-dwelling older adults with mobility disability risk was influenced by the baseline SPPB score, BMI, and grip strength value. To increase the proportion of responders, strategies that could be more effective include constituting more homogenous group, and implementing a specific approach for obese sarcopenic older adults and those with low grip strength by increasing the dose of physical activity and monitoring endurance and mobility activities between sessions. Our results provide important consideration for the development of targeted-interventions.

Heterogeneity of the strength response to progressive resistance exercise training in older adults: Contributions of muscle contractility

BACKGROUND

Older adults display wide individual variability (heterogeneity) in the effects of resistance exercise training on muscle strength. The mechanisms driving this heterogeneity are poorly understood. Understanding of these mechanisms could permit development of more targeted interventions and/or improved identification of individuals likely to respond to resistance training interventions. Thus, this study assessed potential physiological factors that may contribute to strength response heterogeneity in older adults: neural activation, muscle hypertrophy, and muscle contractility.

METHODS

In 24 older adults (72.3 ± 6.8 years), we measured the following parameters before and after 12 weeks of progressive resistance exercise training: i) isometric leg extensor strength; ii) isokinetic (60°/sec) leg extensor strength; iii) voluntary (neural) activation by comparing voluntary and electrically-stimulated muscle forces (i.e., superimposed doublet technique); iv) muscle hypertrophy via dual-energy x-ray absorptiometry (DXA) estimates of regional lean tissue mass; and v) intrinsic contractility by electrically-elicited twitch and doublet torques. We examined associations between physiological factors (baseline values and relative change) and the relative change in isometric and isokinetic muscle strength.

RESULTS

Notably, changes in quadriceps contractility were positively associated with the relative improvement in isokinetic (r = 0.37-0.46, p ≤ 0.05), but not isometric strength (r = 0.09-0.21). Change in voluntary activation did not exhibit a significant association with the relative improvements in either isometric or isokinetic strength (r = 0.35 and 0.33, respectively; p > 0.05). Additionally, change in thigh lean mass was not significantly associated with relative improvement in isometric or isokinetic strength (r = 0.09 and -0.02, respectively; p > 0.05). Somewhat surprising was the lack of association between exercise-induced changes in isometric and isokinetic strength (r = 0.07).

CONCLUSIONS

The strength response to resistance exercise in older adults appears to be contraction-type dependent. Therefore, future investigations should consider obtaining multiple measures of muscle strength to ensure that strength adaptations are comprehensively assessed. Changes in lean mass did not explain the heterogeneity in strength response for either contraction type, and the data regarding the influence of voluntary activation was inconclusive. For isokinetic contraction, the strength response was moderately explained by between-subject variance in the resistance-exercise induced changes in muscle contractility.

Vitamin D3 supplementation does not enhance the effects of resistance training in older adults

BACKGROUND

Lifestyle therapy with resistance training is a potent measure to counteract age-related loss in muscle strength and mass. Unfortunately, many individuals fail to respond in the expected manner. This phenomenon is particularly common among older adults and those with chronic diseases (e.g. chronic obstructive pulmonary disease, COPD) and may involve endocrine variables such as vitamin D. At present, the effects of vitamin D supplementation on responses to resistance training remain largely unexplored.

METHODS

Ninety-five male and female participants (healthy, n = 71; COPD, n = 24; age 68 ± 5 years) were randomly assigned to receive either vitamin D3 or placebo supplementation for 28 weeks in a double-blinded manner (latitude 61°N, September-May). Seventy-eight participants completed the RCT, which was initiated by 12 weeks of supplementation-only (two weeks with 10 000 IU/day, followed by 2000 IU/day), followed by 13 weeks of combined supplementation (2000 IU/day) and supervised whole-body resistance training (twice weekly), interspersed with testing and measurements. Outcome measures included multiple assessments of muscle strength (nvariables  = 7), endurance performance (n = 6), and muscle mass (n = 3, legs, primary), as well as muscle quality (legs), muscle biology (m. vastus lateralis; muscle fibre characteristics, transcriptome), and health-related variables (e.g. visceral fat mass and blood lipid profile). For main outcome domains such as muscle strength and muscle mass, weighted combined factors were calculated from the range of singular assessments.

RESULTS

Overall, 13 weeks of resistance training increased muscle strength (13% ± 8%), muscle mass (9% ± 8%), and endurance performance (one-legged, 23% ± 15%; whole-body, 8% ± 7%), assessed as weighted combined factors, and were associated with changes in health variables (e.g. visceral fat, -6% ± 21%; [LDL]serum , -4% ± 14%) and muscle tissue characteristics such as fibre type proportions (e.g. IIX, -3% points), myonuclei per fibre (30% ± 65%), total RNA/rRNA abundances (15%/6-19%), and transcriptome profiles (e.g. 312 differentially expressed genes). Vitamin D3 supplementation did not affect training-associated changes for any of the main outcome domains, despite robust increases in [25(OH)D]serum (∆49% vs. placebo). No conditional effects were observed for COPD vs. healthy or pre-RCT [25(OH)D]serum . In secondary analyses, vitamin D3 affected expression of gene sets involved in vascular functions in muscle tissue and strength gains in participants with high fat mass, which advocates further study.

CONCLUSIONS

Vitamin D3 supplementation did not affect muscular responses to resistance training in older adults with or without COPD.

Responsiveness to muscle mass gain following 12 and 24 weeks of resistance training in older women

BACKGROUND

Many factors may influence the magnitude of individual responses to resistance training (RT). How the manipulation of training volume and frequency affects responsiveness level for muscle mass gain in older women has not been investigated.

AIMS

This study had the objective of identifying responders (RP) and non-responders (N-RP) older women for skeletal muscle mass (SMM) gain from a 12-week resistance training (RT) program. Additionally, we analyzed whether the N-RP could gain SMM with an increase in weekly training volume over 12 additional weeks of training.

METHODS

Thirty-nine older women (aged ≥ 60 years) completed 24 weeks of a whole-body RT intervention (eight exercises, 2-3×/week, 1-2 sets of 10-15 repetitions). SMM was estimated by DXA, and the responsive cut-off value was set at two times the standard error of measurement. Participants were considered as RP if they exceeded the cut-off value after a 12-week RT phase, while the N-RP were those who failed to reach the SMM cut-off.

RESULTS

Of the 22 participants considered to be N-RP, only 3 accumulated SMM gains (P = 0.250) that exceeded the cut-off point for responsiveness following 12 additional weeks of training, while 19 maintained or presented negative SMM changes. Of the 17 participants considered to be RP, all continued to gain SMM after the second 12-week RT phase. No significant correlation was observed between the changes in SMM and any baseline aspect of the participants.

CONCLUSIONS

Our results suggest that some older women are RP, while others are N-RP to SMM gains resulting from RT. Furthermore, the non-responsiveness condition was not altered by an increase of training volume and intervention duration while RP participants continue to increase SMM; it appears that RP continue to be RP, and N-RP continue to be N-RP.

Cognitive-Postural Multitasking Training in Older Adults - Effects of Input-Output Modality Mappings on Cognitive Performance and Postural Control

Older adults exhibit impaired cognitive and balance performance, particularly under multi-task conditions, which can be improved through training. Compatibility of modality mappings in cognitive tasks (i.e., match between stimulus modality and anticipated sensory effects of motor responses), modulates physical and cognitive dual-task costs. However, the effects of modality specific training programs have not been evaluated yet. Here, we tested the effects of cognitive-postural multi-tasking training on the ability to coordinate task mappings under high postural demands in healthy older adults. Twenty-one adults aged 65-85 years were assigned to one of two groups. While group 1 performed cognitive-postural triple-task training with compatible modality mappings (i.e., visual-manual and auditory-vocal dual n-back tasks), group 2 performed the same tasks with incompatible modality mappings (i.e., visual-vocal and auditory-manual n-back tasks). Throughout the 6-weeks balance training intervention, working-memory load was gradually increased while base-of-support was reduced. Before training (T0), after a 6-week passive control period (T1), and immediately after the intervention (T2), participants performed spatial dual one-back tasks in semi-tandem stance position. Our results indicate improved working-memory performance and reduced dual-task costs for both groups after the passive control period, but no training-specific performance gains. Furthermore, balance performance did not improve in response to training. Notably, the cohort demonstrated meaningful interindividual variability in training responses. Our findings raise questions about practice effects and age-related heterogeneity of training responses following cognitive-motor training. Following multi-modal balance training, neither compatible nor incompatible modality mappings had an impact on the observed outcomes.

Associations of muscle lipid content with physical function and resistance training outcomes in older adults: altered responses with metformin

Preserving muscle mass and strength is critical for long-term health and longevity. Age-related muscle lipid accumulation has been shown to be detrimental to muscle health. In healthy older individuals, we sought to determine whether muscle lipid content, determined from computed tomography, is associated with self-reported physical function, laboratory-measured performance, and the response to progressive resistance training (PRT), and how metformin may alter these responses (N = 46 placebo, 48 metformin). Using multiple linear regression models adjusted for confounders in a large cohort, we show that intermuscular adipose tissue (IMAT) was not associated with baseline function or response to PRT, contrary to previous reports. On the other hand, thigh muscle density (TMD), as an indicator of intra- and extramyocellular lipid (IMCL and EMCL), remained strongly and independently positively associated with physical function and performance following adjustment. Baseline TMD was inversely associated with gains in strength, independent of muscle mass. Percent change in TMD was positively associated with improved chair stand and increased type II fiber frequency but was not associated with muscle hypertrophy or overall strength gain following PRT. For the first time, we show that metformin use during PRT blunted density and strength gains by inhibiting fiber type switching primarily in those with low baseline TMD. These results indicate that participants with higher muscle lipid content derive the most performance benefit from PRT. Our results further indicate that muscle density may be as influential as muscle size for strength, physical function, and performance in healthy older adults. ClinicalTrials.gov , NCT02308228, Registered on 25 November 2014.

The Interaction between Mobility Status and Exercise Specificity in Older Adults

Many adults older than 60 yr experience mobility limitations. Although physical exercise improves older adults' mobility, differences in baseline mobility produce large variations in individual responses to interventions, and these responses could further vary by the type and dose of exercise. Here, we propose an exercise prescription model for older adults based on their current mobility status.

Acute Cardiopulmonary Response to Interval and Continuous Exercise in Older Adults: A Randomized Crossover Study

ABSTRACT

Linares, AM, Goncin, N, Stuckey, M, Burgomaster, KA, and Dogra, S. Acute cardiopulmonary response to interval and continuous exercise in older adults: a randomized crossover study. J Strength Cond Res XX(X): 000-000, 2020-The purpose of this study was to compare the cardiopulmonary response with different exercise protocols in healthy older adults. Subjects (n = 30; 15 women, age: 69.6 ± 6.2 years) completed an exercise test (MAX) on a cycle ergometer to determine maximal oxygen consumption (V[Combining Dot Above]O2max) and peak power output (PPO). Exercise sessions were randomized: high-intensity interval exercise (HIIE, 1 minute 90% PPO followed by 1 minute 10% PPO, ×10), moderate-intensity continuous exercise (MOD, 20 minutes at 50% PPO), and sprint-interval exercise (SPRT, 20 seconds "all-out" sprints followed by 2 minutes at 50 W, ×3). V[Combining Dot Above]O2max was highest during MAX in men (MAX: 28.2 ± 6.3; MOD: 22.6 ± 4.5; HIIE: 26.7 ± 5.7; SPRT: 26.0 ± 4.3; F(2.1) = 28.6, p = 0.0001, = 0.67), whereas similar peaks were observed between HIIE, SPRT, and MAX in women (MAX: 21.9 ± 6.1; MOD: 18.9 ± 4.5; HIIE: 21.6 ± 5.3; SPRT: 21.7 ± 3.9; F(2.2) = 10.2, p = 0.0001, = 0.42). The peak heart rate (b·min-1) was similar across all exercise sessions in both men (MAX: 148.1 ± 17.1; MOD: 132.6 ± 21.8; HIIE: 144.9 ± 16.6; SPRT: 148.6 ± 14.2; F(1.9) = 9.1, p = 0.001, = 0.41) and women (MAX: 148.1 ± 13.1; MOD: 136.3 ± 18.2; HIIE: 147.0 ± 16.4; SPRT: 148.5 ± 18.0; F(2.0) = 5.3, p = 0.011, = 0.27). The %V[Combining Dot Above]O2 at which sessions were performed varied significantly across individual subjects. In conclusion, older women work at near maximal V[Combining Dot Above]O2 when performing HIIE and SPRT; this has implications for exercise testing and prescription protocols in older adults.

Promoting Active Aging: Lessons Learned in an Implementation Pilot in Primary Care

BACKGROUND

Physical activity (PA) preserves mobility, but few practices screen older adults for mobility impairment or counsel on PA.

DESIGN

"Promoting Active Aging" (PAA) was a mixed-methods randomized-controlled pilot, to test the feasibility and acceptability of a video-based PA counseling tool and implementation into practice of two mobility assessment tools.

SETTING

Three primary care practices affiliated with Wake Forest Baptist Health.

PARTICIPANTS

Adults aged 65 years and older who presented for primary care follow-up and were willing and able to answer self-report questions and walk 4 meters (n = 59).

INTERVENTION

Video-based PA counseling intervention versus control video, "Healthy Eating."

MEASUREMENTS

Potential participants completed mobility assessments: self-report (Mobility Assessment Tool-short form (MAT-sf)) and performance based (4-meter walk test). We assessed PAA's implementation-feasibility, acceptability, and value-via interviews and surveys. Effectiveness was measured via participant attendance at a PA information session.

RESULTS

Of 92 patients approached, 89 (96.7%) agreed to mobility assessment. Eighty-nine completed MAT-sf, and 97.8% (87/89) completed 4-meter walk test. Sixty-seven (75%) met eligibility criteria, and 59 (88%) consented to be randomized either to the PA counseling intervention (Video-PA) or to active control (Video-C). Most participants viewed the walk test positively (51/59; 86.4%). Staff reported that completion of patient surveys, MAT-sf, and videos required significant staff time and support (median = 26 minutes for all), resulting in low acceptability of MAT-sf and the videos. Attendance at a PA information session did not differ by randomization group (Video-PA = 11/29 (37.9%); Video-C = 12/30 (40%); 95% confidence interval for difference in proportion = -0.29 to 0.25).

CONCLUSIONS

Mobility assessment, particularly a 4-meter walk test, was feasible in primary care. Tablet-based assessment (MAT-sf) and video counseling tools, selected to reduce staff effort, instead required significant time to implement. Future work to promote PA should identify effective ways to facilitate adoption of PA in sedentary older adults that do not burden staff.

The Bidirectional Association Between Physical and Cognitive Function Among Chinese Older Adults: A Mediation Analysis

This study investigated the bidirectional association between physical and cognitive function in later life and examined the mechanisms underlying the interrelationship. We employed cross-lagged panel models to analyze a sample of 4232 unique participants aged 65 years and older from three waves of the Chinese Longitudinal Healthy Longevity Survey. Physical activity and social participation were tested as potential mediators between physical and cognitive function. Our findings revealed a reciprocal relationship between physical and cognitive function and a reciprocal relationship between physical and cognitive decline. Moreover, physical activity was confirmed to mediate the bidirectional association between physical and cognitive function, whereas social participation did not seem to be a mediator. A vicious cycle linking physical and cognitive decline may exist in Chinese older adults. However, leading a physically active lifestyle could be an effective intervention to slow physical and cognitive aging, thereby toning down the vicious cycle.

Spexin as an indicator of beneficial effects of exercise in human obesity and diabetes

Spexin is a novel neuropeptide playing an emerging role in metabolic diseases such as obesity and diabetes via involvement in energy homeostasis and food intake. The present study investigated the effects of obesity and type 2 diabetes (T2D) on circulating levels of spexin and its modulation by physical exercise. Normal-weight (n = 50) and obese adults with and without T2D (n = 69 and n = 66, respectively) were enrolled in the study. A subgroup of obese participants (n = 47) underwent a supervised 3-month exercise programme. Plasma spexin levels were measured by ELISA and correlated with various markers. Plasma spexin levels decreased in obese participants with or without T2D compared with those of normal-weight participants (0.43 ± 0.11, 0.44 ± 0.12 and 0.61 ± 0.23 ng/ml, respectively; P < 0.001). Spexin levels negatively correlated with adiposity markers and blood pressure in the whole study population (P < 0.05). Multiple regression analysis revealed blood pressure was the greatest predictive determinant of plasma spexin levels, which significantly increased in response to physical exercise in obese participants without and with T2D (P < 0.05). Spexin levels significantly increased only in responders to exercise (those with increased oxygen consumption, VO₂ max) with a concomitant improvement in metabolic profile. In conclusion, plasma spexin levels may be an indicator of response to physical exercise.

Nicotinamide riboside-A missing piece in the puzzle of exercise therapy for older adults?

Maintaining physical mobility is important for preventing age-related comorbidities in older adults. Endurance and resistance training prevent mobility loss in aging, but exercise alone does not always achieve the expected improvements in physical and cardiopulmonary function. Recent preclinical evidence suggests that a reason for the variability in exercise training responses may be the age-related dysregulation of the nicotinamide adenine dinucleotide (NAD+) metabolome. NAD+ is an essential enzymatic cofactor in energetic and signaling pathways. Endogenous NAD+ pool is lower in several chronic and degenerative diseases (e.g., cardiovascular diseases, Alzheimer's and Parkinson's diseases, muscular dystrophies), and also in aging. Exercise requires a higher energy expenditure than a resting state, thus a state of NAD+ insufficiency with reduced energy metabolism, could result in an inadequate exercise response. Recently, the NAD+ precursor nicotinamide riboside (NR), a vitamin B3 derivate, showed an ability to improve NAD+ metabolome homeostasis, restoring energy metabolism and cellular function in various organs in animals. NR has also been tested in older humans and is considered safe, but the effects of NR supplementation alone on physical performance are unclear. The purpose of this review is to examine the preclinical and clinical evidence on the effect of NR supplementation strategies alone and in combination with physical activity on mobility and skeletal muscle and cardiovascular function.

Low-Load Resistance Training Performed to Muscle Failure or Near Muscle Failure Does Not Promote Additional Gains on Muscle Strength, Hypertrophy, and Functional Performance of Older Adults

Bergamasco, JGA, Gomes da Silva, D, Bittencourt, DF, Martins de Oliveira, R, Júnior, JCB, Caruso, FC, Godoi, D, Borghi-Silva, A, and Libardi, CA. Low-load resistance training performed to muscle failure or near muscle failure does not promote additional gains on muscle strength, hypertrophy, and functional performance of older adults. J Strength Cond Res XX(X): 000-000, 2020-The aim of the present study was to compare the effects of low-load resistance training (RT) protocols performed to failure (FAI), to voluntary interruption (VOL), and with a fixed low repetitions (FIX) on muscle strength, hypertrophy, and functional performance in older adults. Forty-one subjects (60-77 years) were randomized into one of the RT protocols (FAI, VOL, or FIX) and completed 12 weeks of RT at 40% of 1 repetition maximum (1RM), twice a week. The assessments included 1RM test, muscle cross-sectional area (CSA), rate of torque development (RTD), and functional performance (chair stand [CS], habitual gait speed [HGS], maximal gait speed [MGS], and timed up-and-go [TUG]). All protocols significantly increased 1RM values from Pre (FAI: 318.3 ± 116.3 kg; VOL: 342.9 ± 93.7 kg; FIX: 328.0 ± 107.2 kg) to Post (FAI: 393.0 ± 143.1 kg, 23.5%; VOL: 423.0 ± 114.5 kg, 23.3%; FIX: 397.8 ± 94.6 kg, 21.3%; p < 0.0001 for all groups). Regarding CS, all protocols showed significant improvements from Pre (FAI: 11.5 ± 2.4 seconds; VOL: 12.1 ± 2.5 seconds; FIX: 11.3 ± 1.1 seconds) to Post (FAI: 10.5 ± 1.1 seconds, -8.5%, p = 0.001; VOL: 10.3 ± 1.5 seconds, -15.1%, p = 0.001; FIX: 11.0 ± 1.1, -3.2%, p = 0.001). Habitual gait speed values increased significantly from Pre (FAI: 1.3 ± 0.2 m·s; VOL: 1.3 ± 0.1 m·s; FIX: 1.3 ± 0.1 m·s) to Post (FAI: 1.4 ± 0.2 m·s, 2.5%, p = 0.03; VOL: 1.4 ± 0.2 m·s, 5.2%, p = 0.036; FIX: 1.4 ± 0.1 m·s, 5.7%, p = 0.03). No significant differences between protocols were found (p > 0.05). In addition, there were no significant changes in CSA, RTD, MGS, and TUG for any protocols (p > 0.05). In conclusion, low-load RT performed without muscle failure promotes significant improvements in muscle strength and some parameters of functional performance in older adults.

Vascular improvements in individuals with type 2 diabetes following a 1 year randomised controlled exercise intervention, irrespective of changes in cardiorespiratory fitness

AIMS/HYPOTHESIS

Vascular changes in individuals with type 2 diabetes mellitus majorly contribute to the development of cardiovascular disease. Increased cardiorespiratory fitness (CRF) has been associated with improvements in vascular health. Although CRF tends to improve with exercise training, there remains a portion of participants with little or no improvement. Given the importance of vascular function in individuals with type 2 diabetes, we assessed whether individuals who failed to improve CRF following a 1 year exercise intervention also failed to improve arterial stiffness and structural indices.

METHODS

Individuals with type 2 diabetes with no major micro- and macrovascular complications and aged between 30 and 75 years old (n = 63) participated in a three-arm, 1 year, randomised controlled exercise intervention in Lisbon, Portugal. The study involved a non-exercise control group, a moderate continuous training combined with resistance training (RT) group and a high-intensity interval training with RT group. Allocation of participants into the intervention and control groups was done using a computer-generated list of random numbers. An improvement in CRF was defined as a change in [Formula: see text] ≥5%. Vascular stiffness and structural indices were measured using ultrasound imaging and applanation tonometry. Generalised estimating equations were used to compare changes in vascular measures across individuals in the control group (n = 22) and those in the exercise groups who either had improved CRF (CRF responders; n = 14) or whose CRF did not improve (CRF non-responders; n = 27) following 1 year of exercise training.

RESULTS

Compared with the control group, exercisers, with and without improvements in CRF, had decreased carotid intima-media thickness (IMT) (CRF responders: β = -2.84 [95% CI -5.63, -0.04]; CRF non-responders: β = -5.89 [95% CI -9.38, -2.40]) and lower-limb pulse wave velocity (PWV) (CRF responders: β = -0.14 [95% CI -0.25, -0.03]; CRF non-responders: β = -0.14 [95% CI -0.25, -0.03]), the latter being an indicator of peripheral arterial stiffness. Only CRF responders had decreased PWV of the upper limb compared with control participants (β = -0.12 [95% CI -0.23, -0.01]). As for central stiffness, CRF non-responders had increased aortic PWV compared with CRF responders (β = 0.19 [95% CI 0.07, 0.31]), whereas only the CRF non-responders had altered carotid distensibility coefficient compared with the control group (β = 0.00 [95% CI 3.01 × 10^-5, 0.00]). No interaction effects between the CRF responders and non-responders vs control group were found for the remaining stiffness or haemodynamic indices (p>0.05).

CONCLUSIONS/INTERPRETATION

Regardless of improvements in CRF, individuals with type 2 diabetes had significant improvements in carotid IMT and lower-limb arterial stiffness following a 1 year exercise intervention. Thus, a lack of improvement in CRF following exercise in people with type 2 diabetes does not necessarily entail a lack of improvement in vascular health.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03144505 FUNDING: This work was supported by fellowships from the Portuguese Foundation for Science and Technology. This work is also financed by a national grant through the Fundação para a Ciência e Tecnologia (FCT), within the unit I&D 472.

Association of Fish Oil and Physical Activity on Mobility Disability in Older Adults

PURPOSE

This study aimed to examine whether long-term fish oil (FO) supplementation is associated with a lower risk of mobility disability and enhances benefits of physical activity (PA).

METHODS

A total of 1635 sedentary adults age 70 to 89 yr from the Lifestyle Interventions and Independence for Elders single-blinded randomized, multicenter clinical trial, which compared a structured PA program to a health education program. Primary outcome was incident major mobility disability (MMD), defined by loss of ability to walk 400 m, measured every 6 months for an average of 2.6 yr. Secondary outcomes included persistent mobility disability, Short Physical Performance Battery, 400-m walk speed, and grip strength.

RESULTS

A third of participants reported using FO at baseline (456 (28%); mean age, 78.5 yr; 70.5% women). MMD was experienced by 131 participants (28.7%) in the FO group and 405 (34.4%) participants in the nonuser group. After adjusting for confounders, FO supplementation was associated with a lower risk (HR, 0.78; 95% confidence interval (CI), 0.64-0.96) of incident MMD. However, there was no interaction (P = 0.19) between FO supplementation and PA intervention for MMD. For the secondary outcome of persistent mobility disability, the intervention association differed by supplementation (P = 0.002) with PA intervention associations of (HR, 1.36; 95% CI, 0.83-2.23) for users and (HR, 0.61; 95% CI, 0.46-0.81) for nonusers. Changes in physical performance outcomes were not modified by baseline FO supplementation or combination with PA.

CONCLUSIONS

FO supplementation was associated with a lower risk of MMD in low to moderate functioning older adults. However, supplementation did not enhance the benefit of PA on risk of mobility disability. These results are hypothesis generating and need to be confirmed in randomized trials.

Incidence of V˙O2max Responders to Personalized versus Standardized Exercise Prescription

INTRODUCTION

Despite knowledge of cardiorespiratory fitness (CRF) training responders and nonresponders, it is not well understood how the exercise intensity prescription affects the incidence of response. The purpose of this study was to determine CRF training responsiveness based on cohort-specific technical error after 12 wk of standardized or individually prescribed exercise and the use of a verification protocol to confirm maximal oxygen uptake (V˙O2max).

METHODS

Sedentary adult participants (9 men, 30 women; 48.2 ± 12.2 yr) completed exercise training on 3 d·wk for 12 wk, with exercise intensity prescribed based on standardized methods using heart rate reserve or an individualized approach using ventilatory thresholds. A verification protocol was used at baseline and 12 wk to confirm the identification of a true V˙O2max and subsequent relative percent changes to quantify CRF training responsiveness. A cohort-specific technical error (4.7%) was used as a threshold to identify incidence of response.

RESULTS

Relative V˙O2max significantly increased (P < 0.05) from 24.3 ± 4.6 to 26.0 ± 4.2 and 29.2 ± 7.5 to 32.8 ± 8.6 mL·kg·min for the standardized and individualized groups, respectively. Absolute V˙O2max significantly increased (P < 0.05) from 2.0 ± 0.6 to 2.2 ± 0.6 and 2.4 ± 0.8 to 2.6 ± 0.9 L·min for the standardized and individualized groups, respectively. A significant difference in responsiveness was found between the individualized and standardized groups with 100% and 60% of participants categorized as responders, respectively.

CONCLUSIONS

A threshold model for exercise intensity prescription had a greater effect on the incidence of CRF training response compared with a standardized approach using heart rate reserve. The use of thresholds for intensity markers accounts for individual metabolic characteristics and should be considered as a viable and practical method to prescribe exercise intensity.

Dose-Response Matters! - A Perspective on the Exercise Prescription in Exercise-Cognition Research

In general, it is well recognized that both acute physical exercises and regular physical training influence brain plasticity and cognitive functions positively. However, growing evidence shows that the same physical exercises induce very heterogeneous outcomes across individuals. In an attempt to better understand this interindividual heterogeneity in response to acute and regular physical exercising, most research, so far, has focused on non-modifiable factors such as sex and different genotypes, while relatively little attention has been paid to exercise prescription as a modifiable factor. With an adapted exercise prescription, dosage can be made comparable across individuals, a procedure that is necessary to better understand the dose-response relationship in exercise-cognition research. This improved understanding of dose-response relationships could help to design more efficient physical training approaches against, for instance, cognitive decline.

Assessing differential responders and mean changes in muscle size, strength, and the crossover effect to 2 distinct resistance training protocols

The objective of this study was to determine differences in 2 distinct resistance training protocols and if true variability can be detected after accounting for random error. Individuals (n = 151) were randomly assigned to 1 of 3 groups: (i) a traditional exercise group performing 4 sets to failure; (ii) a group performing a 1-repetition maximum (1RM) test; and (iii) a time-matched nonexercise control group. Both exercise groups performed 18 sessions of elbow flexion exercise over 6 weeks. While both training groups increased 1RM strength similarly (∼2.4 kg), true variability was only present in the traditional exercise group (true variability = 1.80 kg). Only the 1RM group increased untrained arm 1RM strength (1.5 kg), while only the traditional group increased ultrasound measured muscle thickness (∼0.23 cm). Despite these mean increases, no true variability was present for untrained arm strength or muscle hypertrophy in either training group. In conclusion, these findings demonstrate the importance of taking into consideration the magnitude of random error when classifying differential responders, as many studies may be classifying high and low responders as those who have the greatest amount of random error present. Additionally, our mean results demonstrate that strength is largely driven by task specificity, and the crossover effect of strength may be load dependent. Novelty Many studies examining differential responders to exercise do not account for random error. True variability was present in 1RM strength gains, but the variability in muscle hypertrophy and isokinetic strength changes could not be distinguished from random error. The crossover effect of strength may differ based on the protocol employed.

Effects of a 6-Week Faroese Chain Dance Programme on Postural Balance, Physical Function, and Health Profile in Elderly Subjects: A Pilot Study

The present pilot study investigates the impact of a Faroese chain dance intervention on health profile, mobility, and postural balance in elderly subjects. Healthy elderly subjects (n=27; age 75 ± 5 yrs) were randomised into an intervention group (IG) and a control group (CG). IG performed twice-weekly sessions of Faroese chain dance over 6 weeks. Dancing sessions lasted 30 min in the initial 3 weeks and 45 min in the final 3 weeks. Health profile was determined before and after intervention by measuring blood pressure, resting heart rate, muscle mass, and body fat content. Postural balance was evaluated using the Berg Balance Scale (BBS) and Fullerton Advanced Balance Scale (FAB) tests, while mobility was assessed using the Short Physical Performance Battery (SPPB), the Timed Up & Go (TUG) test, the 6-min walk test, and the 30-s sit-to-stand test. Systolic and diastolic blood pressure were lowered (9 ± 6 and 6 ± 3 mmHg, respectively) in IG, with a tendency (P=0.07) for a greater change score than in CG. Mean arterial pressure declined (P<0.05) by 7 ± 3 mmHg in IG, which tended (P=0.09) to be greater than in CG. IG improved (P<0.05) on BBS and FAB scores by 3.6 ± 2.1% and 15.8 ± 8.3%, with the change score for FAB being greater (P<0.05) than in CG (0.3 ± 1.6). Moreover, the postintervention SPPB score was improved (P<0.05) more in IG (13.9 ± 7.4%) compared to CG, while performance in the 30-s sit-to-stand, 6-min walk, and TUG tests improved (4–15%; P<0.05) in IG only. Body fat content was reduced (P<0.05) from 36.3 ± 2.8% to 34.8 ± 2.8% in IG, with no between-group differences and no change in CG (34.1 ± 2.8% to 33.7 ± 3.1%). In conclusion, a 6-week Faroese chain dance programme lowers blood pressure and improves postural balance and physical function in elderly.

The Role of Genetic Profile in Functional Performance Adaptations to Exercise Training or Physical Activity: A Systematic Review of the Literature

Background: Variations in genotype may contribute to heterogeneity in functional adaptations to exercise. Methods: A systematic search of eight databases was conducted, and 9,696 citations were screened. Results: Eight citations from seven studies measuring 10 single-nucleotide polymorphisms and nine different functional performance test outcomes were included in the review. There was one observational study of physical activity and six experimental studies of aerobic or resistance training. The ACE (D) allele, ACTN3 (RR) genotype, UCP2 (GG) genotype, IL-6-174 (GG) genotype, TNF-α-308 (GG) genotype, and IL-10-1082 (GG) genotype all predicted significantly superior adaptations in at least one functional outcome in older men and women after prescribed exercise or in those with higher levels of physical activity. Conclusion: There is a small amount of evidence that older adults may have better functional outcomes after exercise/physical activity if they have specific alleles related to musculoskeletal function or inflammation. However, more robust trials are needed.

Effects of acute resistance exercise on proteolytic and myogenic markers in skeletal muscles of former weightlifters and age-matched sedentary controls

BACKGROUND

Former athletes who continue a regular, performance-oriented training throughout life provide a unique model for studying successful aging. With this in mind, the current study aimed to compare the effects of an acute resistance exercise on proteolytic and myogenic markers in older weightlifters and untrained participants.

METHODS

Sixteen older men (8 former weightlifters, 8 age-matched untrained controls) with an age of 61.2±8.2 years volunteered to participate in the study. Two days after assessing 1-RM, an acute exercise protocol (3 sets, 70-75% of one-repetition maximum until voluntary fatigue) was applied unilaterally on the dominant leg while the other leg served as control. Three hours after termination of the exercise, skeletal muscle tissue was obtained from m. vastus lateralis of both legs.

RESULTS

Acute resistance exercise led to an up-regulation (>1.5-fold) of 14 genes in controls and of 13 genes in weightlifters. The transcription factors FOS and early growth response 1 (EGR1), as well as the E3 protein ligase TRIM63 comprised the most responsive genes to resistance exercise (EGR1:15.7-fold increase, P=0.003, FOS: 36.3-fold increase, P<0.001; TRIM63: 2.9-fold increase, P<0.001). In addition, myostatin levels were decreased in the exercised leg (0.6-fold, P<0.001). FOXO3 gene expression was significantly higher in weightlifters than in untrained controls (1.5-fold, P=0.042).

CONCLUSIONS

Trained and untrained older adults respond to an acute bout of resistance exercise in a very similar way irrespective of training status, although some differences exist in FOXO3, potentially reflecting the superior capacity of trained persons in regulating cellular homeostasis.

Personalized Moderate-Intensity Exercise Training Combined with High-Intensity Interval Training Enhances Training Responsiveness

This study sought to determine if personalized moderate-intensity continuous exercise training (MICT) combined with high-intensity interval training (HIIT) was more effective at improving comprehensive training responsiveness than MICT alone. Apparently healthy, but physically inactive men and women (n = 54) were randomized to a non-exercise control group or one of two 13-week exercise training groups: (1) a personalized MICT + HIIT aerobic and resistance training program based on the American Council on Exercise guidelines, or (2) a standardized MICT aerobic and resistance training program designed according to current American College of Sports Medicine guidelines. Mean changes in maximal oxygen uptake (VO_2max) and Metabolic (MetS) z-score in the personalized MICT + HIIT group were more favorable (p < 0.05) when compared to both the standardized MICT and control groups. Additionally, on the individual level, there were positive improvements in VO_2max (Δ > 4.9%) and MetS z-score (Δ ≤ -0.48) in 100% (16/16) of participants in the personalized MICT + HIIT group. In the present study, a personalized exercise prescription combining MICT + HIIT in conjunction with resistance training elicited greater improvements in VO_2max, MetS z-score reductions, and diminished inter-individual variation in VO_2max and cardiometabolic training responses when compared to standardized MICT.

Time Course Changes in Confirmed 'True' VO 2 max After Individualized and Standardized Training

This study sought to examine time course changes in maximal oxygen consumption (VO ₂ max) confirmed with verification testing following 12 weeks of standardized vs. individualized exercise training. Participants (N=39) were randomly allocated to differing exercise intensity prescription groups: ventilatory threshold (individualized) or % heart rate reserve (standardized). At baseline, 4, 8, and 12 weeks, participants completed maximal exercise testing with a verification protocol to confirm ‘true VO ₂ max.’ VO ₂ max in the standardized group changed from 24.3±4.6 ml·kg ⁻¹ ·min ⁻¹ at baseline to 24.7±4.6, 25.9±4.7, and 26.0±4.2 ml·kg ⁻¹ ·min ⁻¹ at week 4, 8, and 12, respectively, with a significant difference (p<0.05) in VO ₂ max at week 8 and 12 compared to baseline. The individualized group had increases in VO ₂ max from _{online 2} 9.5±7.5 ml·kg ⁻¹ ·min ⁻¹ at baseline to 30.6±8.4, 31.4±8.4, and 32.8±8.6 ml·kg ⁻¹ ·min ⁻¹ at week 4, 8, and 12, respectively. In the individualized group, there were significant differences (p<0.05) in VO ₂ max from baseline to week 8 and 12 and a significant increase in VO ₂ max from week 8 to 1 _{online 2} . Although not statistically significant, our preliminary data demonstrates a more rapid and potent improvement in VO ₂ max when exercise intensity is individualized. This is the first investigation to employ use of the verification procedure to confirm ‘true VO ₂ max’ changes following exercise training using ventilatory thresholds.

Physical Exercise as Personalized Medicine for Dementia Prevention?

Accumulating evidence mainly from observational studies supports the notion that lifestyle factors such as regular physical activity can modulate potential risk factors of dementia. Regarding a potential mechanism for this interaction, results from intervention studies show that exercising can induce neuroplastic changes in the human brain. However, a detailed look at the study results reveals a wide interindividual variability in the observed effects. This heterogeneity may originate from the fact that there are “responders” and “non-responders” with respect to the impact of physical exercise on physiological outcome parameters (i.e., VO₂ peak) and the brain. From this, it follows that recommendations for physical exercise programs should not follow a “one size fits all” approach. Instead, we propose that the exercises should be tailored to an individual in order to maximize the potential neuroplastic and preventive effects of regular exercise. These adaptations should take the individual performance levels into account and impact both the quality (i.e., type) and the quantity of exercises (i.e., intensity, duration, and volume).

Prehabilitation is better than cure

PURPOSE OF REVIEW

With a continuously growing number of older patients undergoing major surgical procedures, reliable parameters practicable in perioperative routine revealing those patients at risk are urgently needed. Recently, the concept of 'prehabilitation' with its key elements exercise, nutrition and psychological stress reduction especially in frail patients is attracting increasing attention.

RECENT FINDINGS

Literature search revealed a huge amount of publications in particular within the last 12 months. Although a single definition of both frailty and prehabilitation is still to be made, various players in the perioperative setting obviously are becoming increasingly convinced about a possible benefit of the program - referring to different components and measures performed. Although physiologically advantages seem obvious, there is hardly any reliable data on clinical outcomes resulting from properly performed studies. This applies especially to octogenarians; thus those at risk for adverse events the concept originally addresses.

SUMMARY

Identifying high-risk patients at the earliest possible stage and increasing their physiological reserve prior to surgery is a promising approach that seems to result in remarkable improvements for older patients. However, further studies on effectiveness in a highly heterogeneous population and agreement on a common concept are mandatory before a final judgement can be given.

Precision exercise medicine: understanding exercise response variability

There is evidence from human twin and family studies as well as mouse and rat selection experiments that there are considerable interindividual differences in the response of cardiorespiratory fitness (CRF) and other cardiometabolic traits to a given exercise programme dose. We developed this consensus statement on exercise response variability following a symposium dedicated to this topic. There is strong evidence from both animal and human studies that exercise training doses lead to variable responses. A genetic component contributes to exercise training response variability.

In this consensus statement, we (1) briefly review the literature on exercise response variability and the various sources of variations in CRF response to an exercise programme, (2) introduce the key research designs and corresponding statistical models with an emphasis on randomised controlled designs with or without multiple pretests and post-tests, crossover designs and repeated measures designs, (3) discuss advantages and disadvantages of multiple methods of categorising exercise response levels—a topic that is of particular interest for personalised exercise medicine and (4) outline approaches that may identify determinants and modifiers of CRF exercise response. We also summarise gaps in knowledge and recommend future research to better understand exercise response variability.

The Importance of Resistance Exercise Training to Combat Neuromuscular Aging

Older adults undergoing age-related decrements in muscle health can benefit substantially from resistance exercise training, a potent stimulus for whole muscle and myofiber hypertrophy, neuromuscular performance gains, and improved functional mobility. With the use of advancing technologies, research continues to elucidate the mechanisms of and heterogeneity in adaptations to resistance exercise training beyond differences in exercise prescription. This review highlights the current knowledge in these areas and emphasizes knowledge gaps that require future attention of the field.

Effectiveness of HIIT compared to moderate continuous training in improving vascular parameters in inactive adults

BACKGROUND

Strong evidence shows that physical inactivity increases the risk of many adverse health conditions, including major non-communicable diseases, such as cardiovascular disease (CVD), metabolic syndrome, and breast and colon cancers, and shortens life expectancy. We aimed to determine the effects of moderate (MCT)- versus high-intensity interval training (HIT) on vascular function parameters in physically inactive adults. We hypothesized that individualized HIT prescription would improve the vascular function parameters more than the MCT in a greater proportion of individuals.

METHODS

Twenty-one inactive adults were randomly allocated to receive either MCT group (60-75% of their heart rate reserve, [HRR] or HIT group (4 min at 85-95% of peak HRR), 3 days a week for 12 weeks. Vascular function (brachial artery flow-mediated dilation, FMD [%], normalized brachial artery flow-mediated dilation, FMDn [%], aortic pulse wave velocity, PWV [m·s- 1], AIx, augmentation index: aortic and brachial [%]), were measured at baseline and over 12 weeks of training. In order for a participant to be considered a responder to improvements in vascular function parameters (FMDn and PWV), the typical error was calculated in a favorable direction.

RESULTS

FMD changed by - 1.0% (SE 2.1, d = 0.388) in the MCT group, and + 1.8% (SE 1.8, d = 0.699) in the HIT group (no significant difference between groups: 2.9% [95% CI, - 3.0 to 8.8]. PWV changed by + 0.1 m·s- 1 (SE 0.2, d = 0.087) in the MCT group but decreased by - 0.4 m·s- 1 in the HIT group (SE 0.2, d = 0.497), with significant difference between groups: - 0.4 [95% CI, - 0.2 to - 0.7]. There was not a significant difference in the prevalence of no-responder for FMD (%) between the MCT and HIT groups (66% versus 36%, P = 0.157). Regarding PWV (m·s- 1), an analysis showed that the prevalence of no-responder was 77% (7 cases) in the MCT group and 45% (5 cases) in the HIT group (P = 0.114).

CONCLUSIONS

Under the conditions of the present study, both groups experienced changed in vascular function parameters. Compared to MCT group, HIT is more efficacious for improving FMD and decreasing PWV, in physically inactive adults.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02738385 registered on 23 March 2016.

Response heterogeneity in fitness, mobility and cognition with exercise-training in MS

BACKGROUND

Exercise-training is a beneficial approach for improving function in persons with multiple sclerosis (MS). However, it is unlikely that every participant who engages in an exercise-training intervention will demonstrate similar benefits. Identifying factors that may influence the accrual of specific exercise-training benefits can aid in the development of optimized rehabilitation interventions for improving specific outcomes in MS.

OBJECTIVE

This study described possible response heterogeneity in physical fitness, mobility and cognitive outcomes with exercise-training and identified baseline performance, compliance and demographic/clinical outcomes as possible predictors of exercise-related changes in those outcomes.

METHODS

Thirty-two persons with MS-related mobility disability completed 6-months of multimodal exercise-training. Physical fitness, mobility and cognitive processing speed (CPS) were measured before and after the 6 months.

RESULTS

There was response heterogeneity in fitness, mobility and cognitive outcomes with multimodal exercise-training. Low baseline aerobic fitness, slow walking speed and slow CPS were associated with greater exercise-related improvements in those respective outcomes.

CONCLUSIONS

Those with MS-related mobility disability who have the lowest aerobic fitness, walking speed and CPS might benefit the most from multimodal exercise-training. This provides critical evidence for informing the development of a precision medicine framework for improving targeted outcomes with exercise-training in MS.

Is the Effect of a High-Intensity Functional Exercise Program on Functional Balance Influenced by Applicability and Motivation among Older People with Dementia in Nursing Homes?

BACKGROUND AND OBJECTIVES

Exercise can be an important way of maintaining balance function in people with dementia, but further investigation is needed to determine the optimal way of exercising. The objective was to evaluate whether exercise applicability (i.e., attendance, exercise intensity, and adverse events) and motivation were associated with the effect on functional balance of a high-intensity functional exercise program for older people with dementia in nursing homes.

DESIGN, SETTING AND PARTICIPANTS

Exercise intervention participants (n = 81; 60 women, 21 men) from a randomized controlled trial (UMDEX) were included. Their mean age was 84 and mean Mini-Mental State Examination score was 15.

INTERVENTION

Groups of 3-8 participants participated in the High-Intensity Functional Exercise (HIFE) Program, with 5 sessions per 2-week period, for 4 months (total, 40 sessions).

MEASUREMENTS

Outcome was the Berg Balance Scale (BBS), assessed at baseline and follow up, and the score difference, dichotomized to classify participants into two groups: responders (≥5-point increase) and non-responders (<5-point increase). Target variables were measures of applicability and motivation. Associations between each target variable and the outcome were analyzed using multivariable logistic regression. Baseline characteristics and new medical conditions developing during the intervention period were compared between responders and non-responders and included in the analyses when p < 0.10.

RESULTS

The BBS score was 28.6 ± 14.3 at baseline and 31.2 ± 15.3 at follow up, with the difference between follow-up and baseline scores ranging from -35 to 24. Twenty-nine (35.8%) participants were responders. The multivariable models showed no significant association between responders vs. non-responders and any target variable.

CONCLUSION

Participation in a 4-month high-intensity functional exercise program can improve balance in many individuals with dementia in nursing homes, despite the progressiveness of dementia disorders and several co-existing medical conditions. Predicting balance exercise response based on applicability and motivation seem not to be possible, which lends no support for excluding this group from functional exercise, even when exercise intensity or motivation is not high.

Time course of changes in motor-cognitive exergame performances during task-specific training in patients with dementia: identification and predictors of early training response

Background

Some studies have already suggested that exergame interventions can be effective to improve physical, cognitive, motor-cognitive, and psychological outcomes in patients with dementia (PwD). However, little is known about the training volume required to induce such positive effects and the inter-individual differences in training response among PwD. The aim of the study was to analyze the time course of changes in motor-cognitive exergame performances during a task-specific training program and to identify predictors of early training response in PwD.

Methods

Secondary analyses of data from the intervention group (IG) of a randomized, placebo-controlled trial to improve motor-cognitive performances in PwD. Fifty-six geriatric patients with mild-to-moderate dementia randomized to the IG underwent a 10-week, task-specific training program (2×/week) on an exergame-based balance training system (Physiomat®), combining postural control tasks with cognitive tasks of an established neuropsychological test (Trail Making Test). Main outcome was the time required to complete different Physiomat®-Tasks (PTs) assessed at baseline (T1), training session 7 (TS7) and 14 (TS14), and post-intervention after 20 training sessions (T2). Reliable change indices were used to identify early responders from T1 to TS7. A multivariate logistic regression analysis was performed to determine independent predictors of early training response.

Results

Completion time significantly improved already from T1 to TS7 in all PTs (p ≤ .001–.006), with moderate to very large effect sizes (r = .38–.52; Cohen’s d = .85–1.45). For most PTs, significant progressive improvements from TS7 to TS14 and TS14 to T2 were not observed. Thirty-one (59.6%) participants were classified as early responders and 21 (40.4%) as non-early responders. Lower baseline exergame performance and lower visuospatial and divided attention abilities were independently associated with early training response.

Conclusions

Substantial task-specific improvements in complex motor-cognitive exergame performances can be obtained within a surprisingly short intervention period in PwD. Our results confirm that not only an excellent training response can be achieved in this patient population, but also that more vulnerable patients with greater deficits in domain-specific cognitive functions associated with fall risk may even reap the most and fastest benefit from motor-cognitive exergame interventions.

Trial registration

ISRCTN registry, ISRCTN37232817 (retrospectively registered on 04/02/2012).

Variability in Individual Response to Aerobic Exercise Interventions Among Older Adults

Although a plethora of evidence supports the benefits of exercise among older adults, a majority of studies have emphasized group differences, while giving little, if any, attention to individual differences. Given the lack of data on variability in response, the present review examined how nonresponse to aerobic exercise has been defined in older adult populations and characteristics associated with nonresponse among older adults. The results of this review suggest that interindividual variability in response of maximal oxygen consumption to aerobic exercise interventions is prevalent among older adults (1.4-63.4%); age, sex, race, and body mass index may not be critical determinants of nonresponse; whereas health status, baseline fitness, and exercise dose appear important. Future intervention studies should evaluate and report the variability in individual response of older adults to exercise; investigators should develop programs that allow for modification of components to assist older adults in achieving optimal benefit from exercise programs.

Physical activity intervention for elderly patients with reduced physical performance after acute coronary syndrome (HULK study): rationale and design of a randomized clinical trial

Background

Reduced physical performance and impaired mobility are common in elderly patients after acute coronary syndrome (ACS) and they represent independent risk factors for disability, morbidity, hospital readmission and mortality. Regular physical exercise represents a means for improving functional capacity. Nevertheless, its clinical benefit has been less investigated in elderly patients in the early phase after ACS. The HULK trial aims to investigate the clinical benefit of an early, tailored low-cost physical activity intervention in comparison to standard of care in elderly ACS patients with reduced physical performance.

Design

HULK is an investigator-initiated, prospective multicenter randomized controlled trial (NCT03021044). After successful management of the ACS acute phase and uneventful first 1 month, elderly (≥70 years) patients showing reduced physical performance are randomized (1:1 ratio) to either standard of care or physical activity intervention. Reduced physical performance is defined as a short physical performance battery (SPPB) score of 4–9. The early, tailored, low-cost physical intervention includes 4 sessions of physical activity with a supervisor and an home-based program of physical exercise. The chosen primary endpoint is the 6-month SPPB value. Secondary endpoints briefly include quality of life, on-treatment platelet reactivity, some laboratory data and clinical adverse events. To demonstrate an increase of at least one SPPB point in the experimental arm, a sample size of 226 patients is needed.

Conclusions

The HULK study will test the hypothesis that an early, tailored low-cost physical activity intervention improves physical performance, quality of life, frailty status and outcome in elderly ACS patients with reduced physical performance.

Trial registration

Clinicaltrials.gov, identifier NCT03021044, first posted January, 13th 2017.

Electronic supplementary material

The online version of this article (10.1186/s12872-018-0839-8) contains supplementary material, which is available to authorized users.