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The gradual deterioration of physiological systems with ageing makes it difficult to maintain skeletal muscle mass (sarcopenia), at least partly due to the presence of 'anabolic resistance', resulting in muscle loss. Sarcopenia can be transiently but markedly accelerated through periods of muscle disuse‐induced (i.e., unloading) atrophy due to reduced physical activity, sickness, immobilisation or hospitalisation. Periods of disuse are detrimental to older adults' overall quality of life and substantially increase their risk of falls, physical and social dependence, and early mortality. Disuse events induce skeletal muscle atrophy through various mechanisms, including anabolic resistance, inflammation, disturbed proteostasis and mitochondrial dysfunction, all of which tip the scales in favour of a negative net protein balance and subsequent muscle loss. Concerningly, recovery from disuse atrophy is more difficult for older adults than their younger counterparts. Resistance training (RT) is a potent anabolic stimulus that can robustly stimulate muscle protein synthesis and mitigate muscle losses in older adults when implemented before, during and following unloading. RT may take the form of traditional weightlifting‐focused RT, bodyweight training and lower‐ and higher‐load RT. When combined with sufficient dietary protein, RT can accelerate older adults' recovery from a disuse event, mitigate frailty and improve mobility; however, few older adults regularly participate in RT. A feasible and practical approach to improving the accessibility and acceptability of RT is through the use of resistance bands. Moving forward, RT must be prescribed to older adults to mitigate the negative consequences of disuse atrophy. What is the topic of this review?Use of resistance exercise training to prevent or mitigate the disuse‐induced muscle atrophy in an ageing population.What advances does it highlight?The review highlights several potential mechanisms of disuse‐induced muscle atrophy and strategies before, during and following disuse to prevent, mitigate and recover lost muscle. [ABSTRACT FROM AUTHOR]

Background: Opt2Move is a theory-guided moderate and vigorous physical activity (MVPA) promotion trial that uses multiphase optimization strategy (MOST) methodology to evaluate the individual and combined effects of four intervention components in a full factorial experiment among young adult cancer survivors (YACS; N = 304). All participants will receive the core mHealth MVPA intervention, which includes a Fitbit and standard self-monitoring Opt2Move smartphone application. YACS will be randomized to one of 16 conditions to receive between zero and four additional components each with two levels (yes v. no): E-Coach, buddy, general mindfulness, and MVPA-specific mindfulness. Objective: The primary aim is to determine the individual and combined effects of the components on MVPA post-intervention (12-weeks) and at 24-week follow-up. The secondary aim is to examine how changes in MVPA are associated with patient-reported outcomes, light-intensity activity, sedentary time, and sleep duration and quality. Potential mediators and moderators of component effects will also be examined. Results: Results will support the selection of a package of intervention components optimized to maximize MVPA to be tested in a randomized controlled trial. Conclusion: Opt2Move represents the first systematic effort to use MOST to design an optimized, scalable mHealth MVPA intervention for YACS and will lead to an improved understanding of how to effectively change YACS' MVPA and ultimately, improve health and disease outcomes. [ABSTRACT FROM AUTHOR]

PurposeMany prostate cancer survivors experience compromised health-related quality of life (HRQOL) as a result of prostate cancer. We examined relationships between types and intensities of activity and sedentary behavior and prostate cancer-related HRQOL, overall, and by demographic, disease, and treatment characteristics.MethodsAssociations between post-diagnosis activity and sedentary behavior and HRQOL domains (urinary incontinence, urinary irritation/obstruction, bowel, sexual, and vitality/hormonal) were prospectively examined in men diagnosed with non-metastatic prostate cancer in the Health Professionals Follow-up Study (n = 1917) using generalized linear models.ResultsAfter adjusting for potential confounders, higher duration of total, non-vigorous, and walking activity was associated with higher vitality/hormonal functioning scores (p-trends,

Background: Most adults are insufficiently active. Mindfulness training may increase moderate to vigorous physical activity (MVPA) adoption and adherence. However, physiological and psychological factors underlying these effects are not well understood. This study examined the effects of an acute bout of MVPA, mindfulness training, and combined MVPA and mindfulness training on physiological and psychological outcomes. Methods: Healthy adults (N = 29, Mage = 28.6) completed 20-min counterbalanced conditions: (a) mindfulness training (MIND); (b) moderate intensity walking (PA), and (c) moderate intensity walking while listening to MVPA-specific guided mindfulness training (PAMIND). Heart rate (HR), Rating of Perceived Exertion (RPE), Feeling Scale (FS) and Blood Pressure (BP) were measured at rest, at regular intervals during each condition, and post-condition. Mindfulness, state anxiety, and self-efficacy were assessed pre- and post-condition. Results: Average and peak HR, systolic BP (SBP), and RPE were significantly higher, and average and peak FS were significantly lower during the PA and PAMIND conditions compared to MIND (p<0.001). Average RPE was significantly higher for PA compared to PAMIND (p < 0.001). Heart rate, feeling scale, body and mental events mindfulness, and self-efficacy for walking increased from pre to post (all p's< 0.001) for all conditions. Time by condition interactions were significant for change in heart rate, mental events mindfulness, and state anxiety from pre- to post-condition. Conclusion: The physiological response to MVPA and PAMIND were similar. However, RPE was rated lower in the PAMIND condition, which could have implications for MVPA adoption and maintenance. Future work should further explore RPE combining MVPA and mindfulness training. [ABSTRACT FROM AUTHOR]

Aim: Active travel is advised to help meet recommended weekly physical activity levels. However limited research has examined active travel associations with health indicators. The aim of this study is to investigate active commuting associations with BMI and self-rated health (SRH) using data from the Healthy Ireland Survey. Subjects and methods: Cross-sectional analysis of data was conducted from a nationally representative study of the Irish population. Participants who worked or attended education (n = 4038) provided information regarding their most common travel mode to work or education and demographic, lifestyle and health characteristics during an interview. Following comparative analysis, multivariable logistic regression was used to investigate associations between active commuting modes and overweight, obesity and SRH. Results: Active commuting was associated with decreased likelihood of obesity (AOR 0.69, 95% CI = 0.52, 0.90) relative to non-active commuting. Examination of active commuting mode revealed further reduced obesity risk among cyclists (AOR 0.23, 95% CI = 0.09, 0.56) relative to non-cyclists and among those actively travelling ≥3 km (AOR 0.54, 95% CI = 0.30, 0.98). No associations between active commuting and overweight or SRH were observed. Conclusion: Our findings, which indicate an inverse association between active commuting and obesity, represent a significant contribution to the evidence base supporting promotion of active travel for obesity prevention. [ABSTRACT FROM AUTHOR]

Background Moderate to vigorous physical activity (MVPA) interventions improve patient-reported outcomes (PROs) of physical and psychological health among breast cancer survivors (BCS); however, the effects of specific intervention components on PROs are unknown. Purpose To use the Multiphase Optimization Strategy (MOST) to examine overall effects of the Fit2Thrive MVPA promotion intervention on PROs in BCS and explore whether there are intervention component-specific effects on PROs. Methods Physically inactive BCS [ n = 269; M age = 52.5 (SD = 9.9)] received a core intervention (Fitbit + Fit2Thrive smartphone app) and were randomly assigned to one of 32 conditions in a full factorial experiment of five components ("on" vs. "off"): (i) support calls, (ii) deluxe app, (iii) text messages, (iv) online gym, and (v) buddy. Patient-Reported Outcomes Measurement Information System (PROMIS) questionnaires assessed anxiety, depression, fatigue, physical functioning, sleep disturbance and sleep-related impairment at baseline, post-intervention (12-week), and 24-week follow-up. Main effects for all components at each time point were examined using an intention to treat mixed-effects model. Results All PROMIS measures except sleep disturbance significantly improved (p 's <.008 for all) from baseline to 12-weeks. Effects were maintained at 24-weeks. The "on" level of each component did not result in significantly greater improvements on any PROMIS measure compared to the "off" level. Conclusions Participation in Fit2Thrive was associated with improved PROs in BCS, but improvements did not differ for "on" vs. "off" levels for any component tested. The low-resource Fit2Thrive core intervention is a potential strategy to improve PROs among BCS. Future studies should test the core in an RCT and examine various intervention component effects in BCS with clinically elevated PROs. [ABSTRACT FROM AUTHOR]

Breast cancer survivors with obesity have an increased risk of cancer recurrence, second malignancy, and comorbidities. Though physical activity (PA) interventions are needed, investigation of the relationships between obesity and factors influencing PA program aspects among cancer survivors remain understudied. Thus, we conducted a cross-sectional study examining associations amongst baseline body mass index (BMI), PA program preferences, PA, cardiorespiratory fitness, and related social cognitive theory variables (self-efficacy, exercise barriers interference, social support, positive and negative outcome expectations) from a randomized controlled PA trial with 320 post-treatment breast cancer survivors. BMI was significantly correlated with exercise barriers interference (r = 0.131, p = 0.019). Higher BMI was significantly associated with preference to exercise at a facility (p = 0.038), lower cardiorespiratory fitness (p < 0.001), lower walking self-efficacy (p < 0.001), and higher negative outcome expectations (p = 0.024), independent of covariates (comorbidity score, Western Ontario and McMaster Universities osteoarthritis index score, income, race, education). Those with class I/II obesity reported a higher negative outcome expectations score compared with class III. Location, walking self-efficacy, barriers, negative outcome expectations, and fitness should be considered when designing future PA programs among breast cancer survivors with obesity. [ABSTRACT FROM AUTHOR]

Although the independent within-person association between physical activity and sedentary behaviour with valence in daily life has been extensively studied, few studies have used compositional data analysis to examine how different movement behaviour compositions are related to valence in daily life. This study aimed to examine the within-person association between wake-time movement behaviour compositions with affective valence and the extent to which replacing time spent sedentary with physical activity was associated with valence within individuals in daily life. A 7-day ecological momentary study design was used whereby 94 Canadian university students (M age = 19.45, SD = 2.21, 78.7 % female) reported on affective valence using an adapted version of the Feeling Scale at 7 randomly timed prompts each day. In addition, activPAL accelerometers were worn continuously by participants on their right thigh for the duration of the study to determine time spent engaging in sedentary behaviours and physical activity. Compositional data analysis with isotemporal substitution models were used to examine the within-person association between movement behaviour compositions and affective valence. The within-person association between movement behaviours and affective valence was weak (r2 = 0.013). Nevertheless, engaging in less sedentary time than usual and instead engaging in physical activity was significantly related to more positive affective valence. Considering light intensity physical activity (LPA) and moderate-to-vigorous intensity physical activity (MVPA) separately, replacing time spent sedentary with time engaged in MVPA and LPA both had a significant positive association on affective valence, although the association with MVPA was stronger than the association with LPA. The results provide unique insights into how replacing sedentary time with physical activity in daily life, especially MVPA, may be associated with more feelings of pleasure. These results may be useful to help inform the development of just-in-time adaptive interventions. • Replacing time sedentary with physical activity related to positive valence. • Replacing sedentary time with MVPA has stronger association with valence than LPA. • Breaking up sedentary time with physical activity may be an effective strategy to promote positive affect. [ABSTRACT FROM AUTHOR]

Background: The benefits of moderate to vigorous physical activity (MVPA) for breast cancer survivors are well established. However, most are insufficiently active. Fit2Thrive used the Multiphase Optimization Strategy methodology to determine the effect of 5 intervention components on MVPA in this population. Methods: Two hundred sixty‐nine participants (mean age, 52.5 years; SD, 9.9 years) received a core intervention (the Fit2Thrive self‐monitoring app and Fitbit) and were randomly assigned to 5 intervention components set to on/off in a full factorial experiment: support calls, deluxe app, buddy, online gym, and text messages. The intervention was delivered over 12 weeks with a 12‐week follow‐up. MVPA was measured via accelerometry at the baseline (T1), at 12 weeks (T2), and at 24 weeks (T3). The main effects and interaction effects at each time point were examined for all components. Results: Trial retention was high: 91.8% had valid accelerometer data at T2 or T3. Across all conditions, there were significant increases in MVPA (+53.6 min/wk; P <.001) and in the proportion of survivors meeting MVPA guidelines (+22.3%; P <.001) at T2 that were maintained but attenuated at T3 (MVPA, +24.6 min/wk; P <.001; meeting guidelines, +12.6%; P <.001). No individual components significantly improved MVPA, although increases were greater for the on level versus the off level for support calls, buddy, and text messages at T2 and T3. Conclusions: The Fit2Thrive core intervention (the self‐monitoring app and Fitbit) is promising for increasing MVPA in breast cancer survivors, but the components provided no additional increases in MVPA. Future research should evaluate the core intervention in a randomized trial and determine what components optimize MVPA behaviors in breast cancer survivors. Systematically testing 5 technology‐supported physical activity promotion intervention components alongside the Fit2Thrive core intervention (Fit2Thrive self‐monitoring app and Fitbit) results in an increase in physical activity after the intervention and at a 12‐week follow‐up in breast cancer survivors. However, increases are not significantly greater with any component turned on versus off. This indicates that the Fit2Thrive core is a promising scalable strategy for increasing moderate to vigorous physical activity. [ABSTRACT FROM AUTHOR]

Objective: Although physical activity is associated with better health outcomes in breast cancer survivors (BCS), activity often declines during cancer treatment. Social cognitive theory (SCT) constructs have been associated with physical activity in post‐treatment BCS, but little is known about the relation between these constructs and physical activity during chemotherapy. Methods: BCS (n = 67; Mage = 48.6 [SD = 10.3]) undergoing chemotherapy wore accelerometers and completed prompts in the morning and at night assessing same‐day and next‐day exercise self‐efficacy, physical and psychological outcome expectations, and goal‐setting for 10 consecutive days (3 days pre‐, day of, and 6 days post‐chemotherapy dose) at three time points (beginning, middle, and end of chemotherapy). Separate mixed models assessed between‐ and within‐person associations of each of the SCT constructs associations with same‐ and next‐day moderate to vigorous physical activity (MVPA) and light physical activity (LPA), independently. Results: Within‐person differences in all SCT variables were statistically significantly related to same‐day MVPA (p's < 0.001) and LPA (p's < 0.001). Every one‐point increase in SCT construct related to an increase in MVPA ranging from (a) 3.70 (self‐efficacy) to 8.02 (physical outcome expectations) minute increase in MVPA and (b) 12.72 (self‐efficacy) to 20.38 (physical outcome expectations) increase in LPA that day. No same‐day between‐person effects nor any next‐day effects were significant. Conclusion: MVPA and LPA were related to same‐day within‐person differences in SCT variables. Interventions targeted at increasing or mitigating chemotherapy‐related declines in daily within‐person changes in SCT constructs could help to increase physical activity among BCS during chemotherapy. [ABSTRACT FROM AUTHOR]

Background: The stimulation of muscle protein synthesis (MPS) by dietary protein is reduced with age. We hypothesized that twice-daily milk consumption would increase daily rates of MPS in older women relative to a nondairy milk alternative and that MPS would be enhanced by increased physical activity (PA).Methods: Twenty-two older women were randomly assigned to 1 of 3 experimental groups: whole milk (WM; n = 7, 69 ± 3 y), skim milk (SM; n = 7, 68 ± 3 y), or an almond beverage (AB; n = 8, 63 ± 3 y). From days 1 to 3, participants consumed a standardized diet (0.8 g protein⋅kg-1 ⋅d-1) and performed their habitual PA (Phase 1, Baseline). From days 4 to 6, participants continued to perform habitual PA, but consumed an intervention diet consisting of the standardized diet plus twice-daily beverages (250 mL each) of either WM, SM, or AB (Phase 2, Diet Intervention). Finally, from days 7 to 9, the intervention diet was consumed, and PA via daily steps was increased to ∼150% of habitual daily steps (Phase 3, Intervention Diet + PA). Deuterated water was ingested throughout the study, and muscle biopsies were taken on days 1, 4, 7, and 10 to measure MPS.Results: Daily MPS rates were not differentially affected by the addition of WM, SM, or AB to a standardized diet. There was, however, a significant effect of study phase such that, when collapsed across conditions, MPS was significantly increased from Phase 1 to Phase 2 (+0.133%⋅d-1; 95% CI: 0.035-0.231; P < 0.01) and further increased from Phase 2 to Phase 3 (+0.156%⋅d-1; 95% CI: 0.063-0.250; P < 0.01).Conclusions: Increasing PA through walking was sufficient to increase daily MPS rates in older women, irrespective of whether dietary protein intake is increased beyond the recommended intake of 0.8 g⋅kg-1 ⋅d-1. The trial was registered at clinicaltrials.gov as NCT04981652. [ABSTRACT FROM AUTHOR]

There is evidence for the physical health benefits of high intensity interval exercise (HIIE), but its public health potential has been challenged. It is purported that compared with moderate-intensity continuous exercise (MICE) the high intensity nature of HIIE may lead to negative affective responses. This systematic review (PROSPERO CRD42017058203) addressed this proposition and synthesised research that compares affective responses to HIIE with MICE and vigorous intensity continuous exercise (VICE), during-, end-, and post-exercise. Searches were conducted on five databases, and findings from 33 studies were meta-analysed using random effects models or narratively synthesised. A meta-analysis of affect showed a significant effect in favour of MICE vs HIIE at the lowest point, during and post-exercise, but not at end, and the narrative synthesis supported this for other affective outcomes. Differences on affect between VICE vs HIIE were limited. Pooled data showed arousal levels were consistently higher during HIIE. For enjoyment there was a significant effect in favour of HIIE vs MICE, no difference for HIIE vs VICE at post-exercise, and mixed findings for during-exercise. Although the findings are clouded by methodological issues they indicate that compared to MICE, HIIE is experienced less positively but post-exercise is reported to be more enjoyable. [ABSTRACT FROM AUTHOR]

Background: Evidence is building that strength training may reduce complications associated with cancer such as fatigue, muscle wasting, and lymphedema, particularly among breast and prostate cancer survivors. Population estimates are available for rates of aerobic physical activity; however, data on strength training in this population are limited. The objective of this study was to identify rates of meeting public health recommendations for strength training and aerobic activity among cancer survivors and individuals with no cancer history. Methods-. Data from the Health Information National Trends Survey (HINTS). Iteration 4 Cycle I and Cycle 2 were combined to conduct the analyses. Missing data were imputed, and weighted statistical analyses were conducted in SAS. Results: The proportion of individuals meeting both strength training and aerobic guidelines were low for both cancer survivors and those without a history of cancer. The odds of meeting strength training guidelines were significantly lower for women with a history of any cancer except breast, compared with women with no history of cancer (OR: 0.70, 95% Cl: 0.51–0.96). Conclusions: More work needs to be done to understand why women with cancers other than breast, may be less inclined to engage in aerobic physical activity and strength training. [ABSTRACT FROM AUTHOR]

We compared cardiometabolic demand and post-exercise enjoyment between continuous walking (CW) and time- and intensity-matched interval walking (IW) in insufficiently active adults. Sixteen individuals (13 females and three males, age 25.3 ± 11.1 years) completed one CW and one IW session lasting 30 min in a randomised-counterbalanced design. For CW, participants walked at a mean intensity of 65–70% predicted maximum heart rate (HRmax). For IW, participants alternated between 3 min at 80% HRmax and 2 min at 50% HRmax. Expired gas was measured throughout each protocol. Participants rated post-exercise enjoyment following each protocol. Mean HR and V˙O2 showed small positive differences in IW vs. CW (2, 95%CL 0, 4 beat.min−1; d = 0.23, 95%CL 0.06, 0.41 and 1.4, 95%CL 1.2 ml.kg−1.min−1, d = 0.36, 95%CL 0.05, 0.65, respectively). There was a medium positive difference in overall kcal expenditure in IW vs. CW (25, 95%CL 7 kcal, d = 0.58, 95%CL 0.33, 0.82). Post-exercise enjoyment was moderately greater following IW vs. CW (9.1, 95%CL 1.4, 16.8 AU, d = 0.62, 95%CL 0.06, 0.90), with 75% of participants reporting IW as more enjoyable. Interval walking elicits meaningfully greater energy expenditure and is more enjoyable than CW in insufficiently active, healthy adults. [ABSTRACT FROM AUTHOR]

Objective: Physical activity has numerous benefits for those with symptomatic knee osteoarthritis (KOA) or knee replacement, yet many individuals engage in insufficient activity. The purpose of this study was to explore beliefs about sedentary behavior, barriers to standing, and program preferences for adults with symptomatic KOA or knee replacement. Methods: Forty‐two individuals ≥50 years with symptomatic KOA or knee replacement completed an online survey assessing current knee pain and function, sitting time, physical activity participation, beliefs about sedentary behavior, and preferences for a sedentary reduction program. Results: Participants indicated barriers to standing were pain, discomfort, or working on a computer. Most participants shared interest to participate in a program to reduce sitting time. Participants chose education, self‐monitoring, and activity tracking as most preferable components for an intervention design. Conclusion: Future interventions to reduce sedentary time may utilize these results to tailor programs for those with symptomatic KOA or knee replacement. [ABSTRACT FROM AUTHOR]

Incorporating peer and professional social support features into remotely delivered, technology-supported physical activity interventions may increase their effectiveness. However, very little is known about survivors' preferences for potential social features. This study explored breast cancer survivors' preferences for both traditional (e.g., coaching calls and peer support) and innovative (i.e., message boards and competitions) social support features within remotely delivered, technology-supported physical activity interventions. Survivors [ N = 96; M age = 55.8 (SD = 10.2)] self-reported demographic and disease characteristics and physical activity. A subset (n = 28) completed semistructured phone interviews. Transcribed interviews were evaluated using a thematic content analysis approach and consensus review. Following interviews, the full sample self-reported preferences for social features for remotely delivered physical activity interventions via online questionnaires. Questionnaire data were analyzed using descriptive statistics. Four themes emerged from interview data: (a) technology increases social connectedness; (b) interest in professional involvement/support; (c) connecting with similar survivors; and (d) apprehension regarding competitive social features. Quantitative data indicated that most survivors were interested in social features including a coach (77.1 per cent), team (66.7 per cent), and exercise buddy (57.3 per cent). Survivors endorsed sharing their activity data with their team (80.0 per cent) and buddy (76.6 per cent), but opinions were mixed regarding a progress board ranking their activity in relation to other participants' progress. Survivors were interested in using a message board to share strategies to increase activity (74.5 per cent) and motivational comments (73.4 per cent). Social features are of overall interest to breast cancer survivors, yet preferences for specific social support features varied. Engaging survivors in developing and implementing remotely delivered, technology-supported social features may enhance their effectiveness. [ABSTRACT FROM AUTHOR]

Objective: The current study examined the psychometric properties and validity of the Multidimensional Outcome Expectations for Exercise Scale (MOEES) in a sample of older adults with physical and functional comorbidities. Methods: Confirmatory factor analysis was used to examine the hypothesized 3-factor model in 108 older adults (M age 85 yr) residing in continuing-care retirement communities. Results: Analyses supported the 3-factor structure of the MOEES reflecting physical, social, and self-evaluative outcome expectations, with a 12-item model providing the best fit. Theorized bivariate associations between outcome expectations and physical activity, self-efficacy, and functional performance were all supported. Conclusions: The 12-item version of the MOEES appears to be a reliable and valid measure of outcome expectations for exercise in this sample of older adults with physical and functional comorbidities. Further examination of the factor structure and the longitudinal properties of this measure in older adults is warranted. [ABSTRACT FROM AUTHOR]

Copyright of Applied Physiology, Nutrition & Metabolism is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: An impaired muscle anabolic response to exercise and protein nutrition is thought to underpin age-related muscle loss, which may be exacerbated by aspects of biological aging that may not be present in older individuals who have undertaken long-term high-level exercise training, or master athletes (MA). The aim of this study was to compare rested-state and exercise-induced rates of integrated myofibrillar protein synthesis (iMyoPS) and intracellular signaling in endurance trained MA and healthy age-matched untrained individuals (Older Controls). Methods: In a parallel study design, iMyoPS rates were determined over 48 h in the rested-state and following a bout of unaccustomed resistance exercise (RE) in OC (n = 8 males; 73.5 ± 3.3 years) and endurance-trained MA (n = 7 males; 68.9 ± 5.7 years). Intramuscular anabolic signaling was also determined. During the iMyoPS measurement period, physical activity was monitored via accelerometry and dietary intake was controlled. Results: Anthropometrics, habitual activity, and dietary intake were similar between groups. There was no difference in rested-state rates of iMyoPS between OC (1.47 ± 0.06%⋅day–1) and MA (1.46 ± 0.08%⋅day–1). RE significantly increased iMyoPS above rest in both OC (1.60 ± 0.08%⋅day–1, P < 0.01) and MA (1.61 ± 0.08%⋅day–1, P < 0.01), with no difference between groups. Akt T h r 308 phosphorylation increased at 1 h post-RE in OC (P < 0.05), but not MA. No other between-group differences in intramuscular signaling were apparent at any time-point. Conclusion: While our sample size is limited, these data suggest that rested-state and RE-induced iMyoPS are indistinguishable between MA and OC. Importantly, the OC retain a capacity for RE-induced stimulation of skeletal muscle remodeling. [ABSTRACT FROM AUTHOR]

Objectives: Physical activity is associated with better quality of life (QOL) among breast cancer survivors. However, it is unknown the extent to which time spent sedentary or replacing this time with active behaviors may affect QOL. Our aim was to determine the effect of substituting time between sedentary and active behaviors on QOL indicators in breast cancer survivors.Methods: An isotemporal substitution approach was used to examine the associations of reallocating time to sedentary and active behaviors measured by accelerometry with Functional Assessment of Cancer Treatment-Breast (FACT-B; total, physical, social, emotional, functional well-being, and breast cancer-specific concerns) and the Hospital Anxiety and Depression Scale (HADS) scores in a pooled analysis of breast cancer survivors (n = 753; Mage  = 56.9 ± 9.5 y) from two observational studies.Results: Reallocating 30 minutes of sedentary time to 30 minutes of moderate-to-vigorous intensity physical activity (MVPA) was associated with improved FACT-B total (B = 3.0; 95% CI, 0.6-4.5), physical well-being (B = 0.8; 95% CI, 0.33-1.2), and functional well-being (B = 0.6; 95% CI, 0.03-1.2) scores. Reallocating 30 minutes of light activity to 30 minutes of MVPA was associated with improved FACT-B total (B = 2.4; 95% CI, 0.3-6.0) and physical well-being (B = 0.72; 95% CI, 0.27-1.2) scores. There was no significant substitution of time effects on HADS scores.Conclusions: Substituting sedentary time with MVPA showed the greatest range of effects across QOL indicators. These results can inform intervention development interventions and more comprehensive activity recommendations for breast cancer survivors. [ABSTRACT FROM AUTHOR]

Copyright of Applied Physiology, Nutrition & Metabolism is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Sarcopenic declines in muscle mass and function contribute to the risk of falls, reduced mobility, and progression to frailty in older persons. Mitigation of sarcopenia can be achieved by consumption of higher quality protein in sufficient quantities, which current research suggests are greater than the recommended intakes of approximately 0.8 g/kg bodyweight/d. In addition, higher levels of physical activity and participation in exercise to support cardiovascular fitness and musculoskeletal function work additively with protein in attenuating sarcopenia. This narrative review provides evidence to support a recommendation for per-meal protein targets in older persons that are underpinned by knowledge of muscle protein turnover. Based on work examining acute dose–responses of muscle protein synthesis (MPS) to protein, a proposed per-meal target for protein intakes is set at approximately 0.4–0.6 g protein/kg bodyweight/meal for older persons. Habitual patterns of dietary protein intake tend to emphasize a skewed protein distribution, which would not maximize muscle anabolism. Observational studies show that more even patterns of protein intake are associated with increased muscle mass and improved muscle function. A food-based approach to achieving these protein targets would be advantageous, and the nutrient density of the protein-containing foods would be particularly important for older persons. Dairy foods provide high-quality protein and contain several nutrients of concern for older persons. This brief review provides an overview of the science underpinning why dairy foods should be a point of nutritional emphasis for older persons. Practical suggestions are provided for implementation of dairy foods into dietary patterns to meet the protein and other nutrient targets for older persons. [ABSTRACT FROM AUTHOR]

Aims and objectives: To examine perceived social and environmental barriers and facilitators for healthy eating and activity before and after knee replacement. Background: Many patients undergoing knee replacement surgery are overweight or obese. While obesity treatment guidelines encourage diet and activity modifications, gaps exist in understanding social and environmental determinants of these behaviours for knee replacement patients. Identifying these determinants is critical for treatment, as they are likely amplified due to patients' mobility limitations, the nature of surgery and reliance on others during recovery. Design: This qualitative study used semi‐structured interviews. Methods: Twenty patients (M = 64.7 ± 9.8 years, 45% female, 90% Caucasian, body mass index 30.8 ± 5.5 kg/m2) who were scheduled for or had recently undergone knee replacement were interviewed. Participants were asked to identify social and environmental factors that made it easier or harder to engage in healthy eating or physical activity. Deidentified transcripts were analysed via constant comparative analysis to identify barriers and facilitators to healthy eating and activity. This paper was written in accordance with COnsolidated criteria for REporting Qualitative research standards. Results: Identified social and environmental healthy eating barriers included availability of unhealthy food and attending social gatherings; facilitators included availability of healthy food, keeping unhealthy options "out of sight," and social support. Weather was the primary activity barrier, while facilitators included access to physical activity opportunities and social support. Conclusions: Results provide salient factors for consideration by clinicians and behavioural programmes targeting diet, activity, and weight management, and patient variables to consider when tailoring interventions. Relevance to clinical practice: Practitioners treating knee replacement patients would be aided by an understanding of patients' perceived social and environmental factors that impede or facilitate surgical progress. Particularly for those directly interacting with patients, like nurses, physiotherapists, or other professionals, support from health professionals appears to be a strong facilitator of adherence to diet and increased activity. [ABSTRACT FROM AUTHOR]

Exercise positively impacts mood and symptoms of depression; however, the mechanisms underlying these effects are not fully understood. Recent evidence highlights a potential role for skeletal muscle-derived transcription factors to influence tryptophan metabolism, along the kynurenine pathway, which has important implications in depression. This has important consequences for older adults, whose age-related muscle deterioration may influence this pathway and may increase their risk for depression. Although exercise training has been shown to improve skeletal muscle mass in older adults, whether this also translates into improvements in transcription factors and metabolites related to the kynurenine pathway has yet to be examined. The aim of the present study was to examine the influence of a 12-wk exercise program on skeletal muscle gene expression of transcription factors, kynurenine aminotransferase (KAT) gene expression, and plasma concentrations of tryptophan metabolites (kynurenines) in healthy older men over 65 yr of age. Exercise training significantly increased skeletal muscle gene expression of transcription factors (peroxisome proliferator-activated receptor-γ coactivator 1α, peroxisome proliferator-activated receptor-α, and peroxisome proliferator-activated receptor-δ: 1.77, 1.99, 2.18-fold increases, respectively, P < 0.01] and KAT isoforms 1–4 (6.5, 2.1, 2.2, and 2.6-fold increases, respectively, P ≤ 0.01). Concentrations of plasma kynurenines were not altered. These results demonstrate that 12 wk of exercise training significantly altered skeletal muscle gene expression of transcription factors and gene expression related to the kynurenine pathway, but not circulating kynurenine metabolites in older men. These findings warrant future research to determine whether distinct exercise modalities or varying intensities could induce a shift in the kynurenine pathway in depressed older adults. [ABSTRACT FROM AUTHOR]

Background: Physical inactivity impairs insulin sensitivity, which is exacerbated with aging. We examined the impact of 2 wk of acute inactivity and recovery on glycemic control, and integrated rates of muscle protein synthesis in older men and women.Methods: Twenty-two overweight, prediabetic older adults (12 men, 10 women, 69 ± 4 y) undertook 7 d of habitual activity (baseline; BL), step reduction (SR; <1,000 steps.d-1 for 14 d), followed by 14 d of recovery (RC). An oral glucose tolerance test was used to assess glycemic control and deuterated water ingestion to measure integrated rates of muscle protein synthesis.Results: Daily step count was reduced (all p < .05) from BL at SR (7362 ± 3294 to 991 ± 97) and returned to BL levels at RC (7117 ± 3819). Homeostasis model assessment-insulin resistance increased from BL to SR and Matsuda insulin sensitivity index decreased and did not return to BL in RC. Glucose and insulin area under the curve were elevated from BL to SR and did not recover in RC. Integrated muscle protein synthesis was reduced during SR and did not return to BL in RC.Conclusions: Our findings demonstrate that 2 wk of SR leads to lowered rates of muscle protein synthesis and a worsening of glycemic control that unlike younger adults is not recovered during return to normal activity in overweight, prediabetic elderly humans.Clinical Trials Registration: ClinicalTrials.gov identifier: NCT03039556. [ABSTRACT FROM AUTHOR]

Purpose: Limited data on the relationship between physical activity and lipoprotein particle profiles exist. Our objective was to investigate associations between objectively measured physical activity and lipoprotein particle size and number, and specifically whether substituting daily sedentary behavior with light activity or moderate-to-vigorous physical activity (MVPA) is associated with beneficial alterations to the lipoprotein profile among adults and those at increased cardiometabolic risk (obese and insulin-resistant subjects). Methods: Sedentary behavior and physical activity intensity and duration were measured for 7 consecutive days using the GENEActiv accelerometer in a cross-sectional adult cohort (n = 396; mean age, 59.6 ± 5.5 yr). Lipoprotein particle size and subclass concentrations were determined using nuclear magnetic resonance spectroscopy. Isotemporal substitution regression modeling quantified the associations between replacing 30 min⋅d-1 of sedentary behavior with equal amounts of light activity and MVPA on lipoprotein profiles. Results: Daily duration of MVPA was inversely associated with large VLDL particles and lipoprotein insulin resistance scores (P < 0.05, after adjustment for sedentary time and other confounding factors). Reallocating 30 min of sedentary time with MVPA, but not light activity, was associated with less large VLDL particles resulting in more favorable average VLDL particle size and improved lipoprotein insulin resistance score (P < 0.05). Analysis of high-cardiometabolic-risk groups revealed similar beneficial alterations to VLDL profiles (P < 0.05) with substitution of sedentary time for MVPA among the insulin-resistant (homeostasis model assessment for insulin resistance ≥75th percentile) but not the obese (body mass index ≥30 kg⋅m-2) individuals. Conclusions: Daily MVPA duration and theoretical replacement of sedentary time with MVPA, but not light activity, were associated with less atherogenic VLDL profiles, particularly among the insulin-resistant individuals. These findings, which require further investigation, highlight the need to develop physical activity interventions aimed at improving atherogenic dyslipidemia and lowering cardiometabolic risk. [ABSTRACT FROM AUTHOR]

Fit2Thrive is a theory-guided physical activity promotion trial using the Multiphase Optimization Strategy (MOST) to test efficacy for improving physical activity of five technology-supported physical activity promotion intervention components among breast cancer survivors. This trial will recruit 256 inactive breast cancer survivors nationwide. All participants will receive the core intervention which includes a Fitbit and standard self-monitoring Fit2Thrive smartphone application which will be downloaded to their personal phone. Women will be randomized to one of 32 conditions in a factorial design involving five factors with two levels: support calls (No vs. Yes), app type (standard vs. deluxe), text messaging (No vs. Yes), online gym (No vs. Yes) and Fitbit Buddy (No vs. Yes). The proposed trial examines the effects of the components on physical activity at 12 and 24 weeks. Results will support the selection of a final package of intervention components that has been optimized to maximize physical activity and is subject to an upper limit of cost. The optimized intervention will be tested in a future trial. Fit2Thrive is the first trial to use the MOST framework to develop and test a physical activity promotion intervention in breast cancer survivors and will lead to an improved understanding of how to effectively change survivors' physical activity. These findings could result in more scalable, effective physical activity interventions for breast cancer survivors, and, ultimately, improve health and disease outcomes. [ABSTRACT FROM AUTHOR]

Satellite cells (SC) are associated with skeletal muscle remodelling after muscle damage and/or extensive hypertrophy resulting from resistance training (RT). We recently reported that early increases in muscle protein synthesis (MPS) during RT appear to be directed toward muscle damage repair, but MPS contributes to hypertrophy with progressive muscle damage attenuation. However, modulations in acute-chronic SC content with RT during the initial (1st-wk: high damage), early (3rd-wk: attenuated damage), and later (10th-wk: no damage) stages is not well characterized. Ten young men (27 ± 1 y, 23.6 ± 1.0 kg·m-2) underwent 10-wks of RT and muscle biopsies (vastus-lateralis) were taken before (Pre) and post (48h) the 1st (T1), 5th (T2) and final (T3) RT sessions to evaluate fibre type specific SC content, cross-sectional area (fCSA) and myonuclear number by immunohistochemistry. We observed RT-induced hypertrophy after 10-wks of RT (fCSA increased ~16% in type II, P < 0.04; ~8% in type I [ns]). SC content increased 48h post-exercise at T1 (~69% in type I [P = 0.014]; ~42% in type II [ns]), and this increase was sustained throughout RT (pre T2: ~65%, ~92%; pre T3: ~30% [ns], ~87%, for the increase in type I and II, respectively, vs. pre T1 [P < 0.05]). Increased SC content was not coupled with changes in myonuclear number. SC have a more pronounced role in muscle repair during the initial phase of RT than muscle hypertrophy resulted from 10-wks RT in young men. Chronic elevated SC pool size with RT is important providing proper environment for future stresses or larger fCSA increases. [ABSTRACT FROM AUTHOR]

Background: Sedentary behaviour, obesity and insulin resistance are associated with pro-inflammatory status. Limited data on whether physical activity modulates inflammatory status and counteracts obesity and insulin resistance associated low-grade inflammation exist. Our objective was to investigate associations between objectively measured physical activity and inflammatory status, and specifically whether substituting daily sedentary behaviour with light activity or moderate to vigorous physical activity (MVPA), is associated with beneficial alterations to the inflammatory profile among middle-aged adults and those at increased cardiometabolic risk (obese and insulin resistant subjects). Methods: Data are from a sub-sample of the Mitchelstown cohort; a population-based cross-sectional sample of 2047 Irish adults. Physical activity intensity and duration were measured in 396 participants for 7-consecutive days using the GENEActiv accelerometer. Isotemporal regression analysis examined the associations between replacing 30 min per day of sedentary behaviour with equal amounts of light activity and MVPA on inflammatory factors (serum acute-phase reactants, adipocytokines, pro-inflammatory cytokines and white blood cells (WBC)). Results: Reallocating 30 min of sedentary time with MVPA was associated with a more favourable inflammatory profile characterized by higher adiponectin and lower complement component C3 (C3), leptin, interleukin 6 (IL-6) and WBC concentrations (P < 0.05). No significant effects were noted with substitution of sedentary time with light activity. Among the obese subjects replacing sedentary behaviour with an equivalent amount of MVPA was associated with lower WBC counts (P < 0.05); no associations were detected among the insulin resistant (HOMA-IR >75th percentile) subjects. Among the non-obese and non-insulin resistant subjects substituting 30 min of sedentary behaviour with MVPA was associated with decreased C3, IL-6 and WBC concentrations. Conclusions: Replacing sedentary behaviour with MVPA modulates pro-inflammatory status. These findings, which highlighttheneedforthedevelopingrandomizedtrialsaimedatlowering cardiometabolic risk, warrant further investigation. [ABSTRACT FROM AUTHOR]