Compared to the determination of exercise thresholds based on systemic changes in blood lactate concentrations or gas exchange data, the determination of breakpoints based on muscle oxygen saturation offers a valid alternative to provide specific information on muscle-derived thresholds. Our study explored the profiles and timing of the second muscle oxygenation threshold (MOT2) in different muscles. Twenty-six cyclists and triathletes (15 male: age = 23 ± 7 years, height = 178 ± 5 cm, body mass = 70.2 ± 5.3 kg; 11 female: age = 22 ± 4 years, height = 164 ± 4 cm, body mass = 58.3 ± 8.1 kg) performed a graded exercise test (GXT), on a cycle ergometer. Power output, blood lactate concentration, heart rate, rating of perceived exertion, skinfolds and muscle oxygen saturation were registered in five muscles (vastus lateralis, biceps femoris, gastrocnemius medialis, tibialis anterior and triceps brachii) and percentage at which MOT2 occurred for each muscle was determinated using the Exponential Dmax. The results of Statistical Parametric Mapping and ANOVA showed that, although muscle oxygenation displayed different profiles in each muscle during a GXT, MOT2 occurred at a similar percentage of the GXT in each muscle (77% biceps femoris, 75% tibalis anterior, 76% gastrocnemius medialis and 72% vastus lateralis) and it was similar that systemic threshold (73% of the GXT). In conclusion, this study showed different profiles of muscle oxygen saturation in different muscles, but without notable differences in the timing for MOT2 and concordance with systemic threshold. Finally, we suggest the analysis of the whole signal and not to simplify it to a breakpoint.

OBJECTIVE: To evaluate the effects of a multicomponent training protocol and detraining on frailty status, physical activity level, sedentary behavior patterns, and physical performance in pre-frail older adults.
METHODS: A randomized controlled blinded trial was conducted with pre-frail older adults (74.8 ± 6.4 years, 70.4% female), who were allocated to receive a multicomponent training (MulTI = 16) or control group (CG = 11), which received guidance to maintain their daily living habits. Assessments of the frailty phenotype, physical activity levels measured by accelerometer, and physical performance (gait speed, timed up and go, short physical performance battery) were conducted at pre-intervention, post-intervention (16 weeks), and follow-up (6 weeks). The effect of the intervention was analyzed using the marginal homogeneity test and the two-way ANOVA with repeated measures.
RESULTS: All older adults who received the MulTI reversed their frailty status to non-frail (p < 0.001), and after follow-up, 87.5% remained non-frail. In the CG, one older adult reversed their frailty status to non-frail and another became frail (p > 0.05), maintaining this status after the follow-up period. Furthermore, only the older adults in the MulTI showed an improvement in gait speed post-intervention, which was maintained through follow-up (p = 0.008). No changes were observed in the other variables.
CONCLUSIONS: The MulTI was efficient to reverse the process of frailty and improving gait speed in pre-frail older adults. However, receiving only the MulTI was not sufficient to increase physical activity levels and reduce sedentary behavior patterns, necessitating the implementation of behavioral change strategies.
BACKGROUND: ClinicalTrials.gov NCT03110419.

BACKGROUND: Delayed neurocognitive recovery (dNCR) can result in unfavorable outcomes in elderly surgical patients. Physical activity (PA) has been shown to improve cognitive function, potentially by reducing systemic inflammatory responses. However, there is a lack of supportive data indicating whether PA has a protective effect against dNCR.
OBJECTIVE: To examine the correlation between dNCR and PA, and to further analyze if pro-inflammatory cytokines mediate this relationship.
METHODS: This study is a prospective nested case-control investigation of elderly patients who had knee replacement surgery. dNCR was defined as a decline in cognitive function compared with baseline by using a battery of neuropsychological tests. PA was assessed with the Physical Activity Scale for the Elderly (PASE). Enzyme-linked immunosorbent assay (ELISA) was used to measure the serum concentrations of IL-6, IL-1β, and TNF-α. Multivariable logistic regression analysis was conducted to assess the association between PA and dNCR. Mediation analysis was employed to evaluate whether pro-inflammatory cytokines mediate the relationship between them.
RESULTS: A cohort of 152 patients was included, resulting in an incidence rate of dNCR of 23.68%. PA was associated with dNCR after full adjustment [OR = 0.199, (95% CI, 0.061; 0.649), P = 0.007]. Mediation analysis showed that the IL-6 mediated the statistical association between PA and dNCR, with mediation proportions (%) of 77.68 (postoperative concentration of IL-6) or 27.58 (the absolute change in IL-6 before and after surgery).
CONCLUSIONS: PA serves as a protective factor against dNCR, possibly through the reduction of pro-inflammatory cytokine concentrations. THE CHINESE CLINICAL TRAIL REGISTRY: : www.http://chictr.org.cn , Registration No. ChiCTR2300070834, Registration date: April 24, 2023.

There is evidence that aerobic exercise improves brain health. Benefits may be modulated by acute physiological responses to exercise, but this has not been well characterized in older or cognitively impaired adults. The randomized controlled trial \'AEROBIC\' (NCT04299308) enrolled 60 older adults who were cognitively healthy (n = 30) or cognitively impaired (n = 30) to characterize the acute brain responses to moderate [45-55% heart rate reserve (HRR)] and higher (65-75% HRR) intensity acute exercise. Each participant received two fluorodeoxyglucose positron emission tomography (FDG-PET) scans, one at rest and one following acute exercise. Change in cerebral glucose metabolism from rest to exercise was the primary outcome. Blood biomarker responses were also characterized as secondary outcomes. Whole grey matter FDG-PET standardized uptake value ratio (SUVR) differed between exercise (1.045 ± 0.082) and rest (0.985 ± 0.077) across subjects [Diff = -0.060, t(58) = 13.8, P < 0.001] regardless of diagnosis. Exercise increased lactate area under the curve (AUC) [F(1,56) = 161.99, P < 0.001] more in the higher intensity group [mean difference (MD) = 97.0 ± 50.8] than the moderate intensity group (MD = 40.3 ± 27.5; t = -5.252, P < 0.001). Change in lactate AUC and FDG-PET SUVR correlated significantly (R2 = 0.179, P < 0.001). Acute exercise decreased whole grey matter cerebral glucose metabolism. This effect tracked with the systemic lactate response, suggesting that lactate may serve as a key brain fuel during exercise. Direct measurements of brain lactate metabolism in response to exercise are warranted. KEY POINTS: Acute exercise is associated with a drop in global brain glucose metabolism in both cognitively healthy older adults and those with Alzheimer\'s disease. Blood lactate levels increase following acute exercise. Change in brain metabolism tracks with blood lactate, suggesting it may be an important brain fuel. Acute exercise stimulates changes in brain-derived neurotrophic factor and other blood biomarkers.

OBJECTIVE: The aim of this study was to analyze the association between participation in fitness-related exercises (FRE) and body image dissatisfaction (BID) in adolescents and evaluate the interaction between physical exercise and nutritional status in this association.
METHODS: A cross-sectional study was conducted in 2015 involving 799 adolescents (10-16 years old) from 14 public schools in Curitiba (PR), Brazil. BID was assessed using the Body Shape Questionnaire and the Silhouette Scale. The FRE was classified as \"does not practice,\" \"practices ≤300 min/week,\" and \"practices >300 min/week\" by the Physical Activity Questionnaire for Adolescents. Poisson and multinomial logistic regressions, adjusted for sex, sexual maturation, and nutritional status analyzed the association of FRE and BID.
RESULTS: The BID prevalence was 28.3%; 52.4% of the adolescents wanted to reduce their silhouettes; and 48.7% did not practice FRE. Adolescents who practiced FRE >300 min/week had a 28% higher prevalence for some level of BID (PR 1.28; 95%CI 1.08-1.52) and a 46% lower chance of wanting to reduce silhouettes (OR 0.54; 95%CI 0.35-0.82), compared to nonpractitioners. There was no interaction between FRE and nutritional status in association with BID.
CONCLUSIONS: The adolescents who practice FRE >300 min/week are likely to have some level of BID and are less likely to report the desire to increase their silhouettes, regardless of their nutritional status.

OBJECTIVE: The aim of this study was to examine the association between bullying victimization and health risk behaviors in adolescents.
METHODS: A representative sample of 1020 adolescents participated in the study. The variables such as bullying, health risk behaviors (tobacco, drugs, alcohol, sedentary behavior, smartphone use, level of physical activity, and sleep), and economic status were assessed using self-reported questionnaires. Odds ratios with 95% confidence intervals (95%CI) were obtained using binary logistic regression and ordinal, gross, and adjusted logistic regression (p<0.05).
RESULTS: Victims of bullying were more likely to smoke (OR 1.75; 95%CI 1.28-2.40), consume alcohol (OR1.43; 95%CI 1.05-1.94), have worse sleep quality (OR 1.94; 95%CI 1.28-2.91), and more sedentary behavior (OR 1.43; 95%CI 1.08-1.89) than those who were not bullied. However, victims were more likely to have high levels of physical activity than their non-bullied peers (OR 1.66; 95%CI 1.22-2.27).
CONCLUSIONS: Bullying victimization was associated with an increased predisposition for the adoption of health risk behaviors. Interestingly, victims were also more prone to participate in physical activity.

Electronic handgrip dynamometry allows for multiple muscle function aspects to be feasibly measured, yet their relationship with lower extremity muscle function is unknown. We sought to determine the relationships between upper and lower extremity mechanical isometric muscle strength, rate of force development (RFD), and endurance by limb dominance in resistance trained adults. The analytic sample included 30 adults aged 32.1 ± 13.5 years. An electronic handgrip dynamometer ascertained upper extremity strength capacity, RFD, and endurance. Lower extremity strength, RFD, and endurance were collected with the isometric feature on an isokinetic knee dynamometer. Limb dominance was self-reported. Pearson correlations were used for the analyses. Each muscle function attribute on the dominant limb of the upper and lower extremities were correlated: r = 0.76 (p < 0.01) for strength, r = 0.37 (p = 0.04) for RFD, and r = -0.48 (p < 0.01) for endurance. Although strength from the non-dominant limbs were correlated (r = 0.67; p < 0.01), no significant correlations were observed for RFD (r = 0.20; p = 0.29) and endurance (r = -0.21; p = 0.26). For adults aged 18-34 years, only upper and lower extremity strength was correlated on the dominant (r = 0.69; p < 0.01) and non-dominant limbs (r = 0.75; p < 0.01); however, strength (r = 0.88; p < 0.01) and endurance (r = -0.68; p = 0.01) were correlated in adults aged 35-70 years. Upper and lower extremity fatigability was likewise correlated in females (r = -0.56; p = 0.01). Our findings suggest that electronic handgrip dynamometry derived strength, RFD, and endurance could be a whole-body indicator of these muscle function attributes given their relationships with the lower extremities. These findings underscore the promise of handgrip dynamometry in routine muscle function assessments across different age groups.

UNASSIGNED: The impact of COVID-19 goes beyond its acute form and can lead to the persistence of symptoms and the emergence of systemic disorders, defined as long-term COVID.
UNASSIGNED: We performed a cross-sectional study that included patients over 18 years of age who recovered from the severe form of COVID-19 at least 60 days after their discharge. Patients and controls were enrolled to undergo transthoracic echocardiography (TTE) using a more sensitive tool, myocardial work, in combination with cardiopulmonary exercise testing (CPET).
UNASSIGNED: A total of 52 patients and 31 controls were enrolled. Significant differences were observed in ejection fraction (LVEF; 62 ± 7 vs. 66 ± 6 %; p = 0.007), global longitudinal strain (LVGLS; -18.7 ± 2.6 vs. -20.4 ± 1.4 %; p = 0.001), myocardial wasted work (GWW; 152 ± 81 vs. 101 ± 54 mmHg; p = 0.003), and myocardial work efficiency (GWE; 93 ± 3 vs. 95 ± 2 %; p = 0.002). We found a significant difference in peak VO2 (24.4 ± 5.4 vs. 33.4 ± 8.8 mL/kg/min; p < 0.001), heart rate (160 ± 14 vs. 176 ± 11 bpm; p < 0.001), ventilation (84.6 ± 22.6 vs. 104.9 ± 27.0 L/min; p < 0.001), OUES% (89 ± 16 vs. 102 ± 22 %; p = 0.002), T ½ (120.3 ± 32 vs. 97.6 ± 27 s; p = 0.002) and HRR at 2 min (-36 ± 11 vs. -43 ± 13 bpm; p = 0.010).
UNASSIGNED: Our findings revealed an increased wasted work, with lower myocardial efficiency, significantly reduced aerobic exercise capacity, and abnormal heart rate response during recovery, which may be related to previously described late symptoms. The reduction in functional capacity during physical exercise is partly associated with a decrease in resting myocardial work efficiency. These findings strongly indicate the need to determine whether these manifestations persist in the long term and their impact on cardiovascular health and quality of life in COVID-19 survivors.

Optimizing endurance exercise intensity prescription is crucial to maximize the clinical benefits and minimize complications for individuals at risk for or with cardiovascular disease (CVD). However, standardization remains incomplete due to variations in clinical guidelines. This review provides a practical and updated guide for health professionals on how to prescribe endurance exercise intensity for cardiovascular rehabilitation (CR) populations, addressing international guidelines, practical applicability across diverse clinical settings and resource availabilities. In the context of CR, cardiopulmonary exercise test (CPET) is considered the gold standard assessment, and prescription based on ventilatory thresholds (VTs) is the preferable methodology. In settings where this approach isn\'t accessible, which is frequently the case in low-resource environments, approximating VTs involves combining objective assessments-ideally, exercise tests without gas exchange analyses, but at least alternative functional tests like the 6-minute walk test-with subjective methods for adjusting prescriptions, such as Borg\'s ratings of perceived exertion and the Talk Test. Therefore, enhancing exercise intensity prescription and offering personalized physical activity guidance to patients at risk for or with CVD rely on aligning workouts with individual physiological changes. A tailored prescription promotes a consistent and impactful exercise routine for enhancing health outcomes, considering patient preferences and motivations. Consequently, the selection and implementation of the best possible approach should consider available resources, with an ongoing emphasis on strategies to improve the delivery quality of exercise training in the context of FITT-VP prescription model (frequency, intensity, time, type, volume, and progression).

Both physical activity and social network size decline as people age. However, limited research has examined if social network size and contact frequency differentially influence physical activity across the adult lifespan. This study aimed to assess if these social network characteristics moderated the relationship between age and physical activity level across adulthood. Multiple regression analyses were conducted to examine the main-effect association between age, past-week physical activity, and past-year physical activity, as well as the moderating effect of social network characteristics (i.e., friend network size, friend contact frequency, relative network size, and relative contact frequency) on age-physical activity associations. The results revealed that friend network size had moderated associations between age and past-week physical activity (β = -7.03; p = .025, f2 = 0.13) and past-year physical activity (β = -585.52; p = .017, f2 = 0.15). Specifically, adults who were older and had smaller friend networks performed more minutes of moderate-vigorous physical activity (MVPA) over the past week and past year; on the other hand, adults who were younger and had larger friend networks performed more minutes of MVPA over the past week and past year. Relative network size, friend contact frequency, and relative contact frequency did not moderate the relationship between age and past-week physical activity and past-year physical activity. These findings suggested that building friend networks throughout adulthood may help promote active living across the adult lifespan.