Resistance Training Is an Effective Tool against Metabolic and Frailty Syndromes

Physical Activity before and After Bariatric Surgery

Lifestyle changes including reduced calorie intake and increased physical activity (PA) improve the prognosis associated with bariatric surgery (BS) and metabolic indices. Early implementation of exercise leads to improved physical performance, better glycemic control and lipid profile, reduces the risks associated with anesthesia, and accelerates recovery from surgery. Undertaking systematic exercise after BS is associated with a better quality of life, improves insulin sensitivity, results in additional weight loss, reduces adverse effects on bone mass, and results in better body composition. The aim of this review was to summarize recommendations for physical activity in patients undergoing BS and to highlight the key role of physical activity in this patient group.

Why don't women engage in muscle strength exercise? An integrative review

ISSUE ADDRESSED

Women are 'at-risk' population for failing to meet muscle strengthening guidelines. Health benefits specific to this exercise mode include maintenance of muscle mass, which is associated with reduced risk of chronic disease and falls. Of significance is the progressive decline in muscle strength exercise participation in women aged 35-54 in Australia. This period is critical for maintaining muscle strength as it establishes foundations for older women's engagement. This integrative review examined available evidence regarding factors influencing muscle strength exercise participation, specifically in women aged 35-54.

METHODS

Seven databases were searched. Study inclusion criteria were: (1) peer reviewed, (2) English language, (3) sample populations of healthy female adults or general adult sample population differentiating females from males, (4) mean age between 35 and 54 years, (5) focused on muscle strength exercise and measured as the primary outcome factors of participation in muscle strength exercise.

FINDINGS

Five of 1895 studies met inclusion criteria. Five key factors were associated with participation in muscle strength exercise of women aged 35-54 years: perceived time constraints; knowledge and education; modality and intensity; social support and behavioural strategies.

CONCLUSIONS

Focused education on strength exercise and guidelines, plus initiatives and strategies that suit the needs of this cohort, are necessary to achieve health and wellbeing benefits. Responsive approaches by health professionals to these women's circumstances can potentially address current low participation levels. SO WHAT?: Creating conditions where health professionals respect a woman's exercise preferences can positively impact these women's musculoskeletal health into older age.

Physical activity in metabolic syndrome

Obesity has become one of the global epidemics, contributing to the burden of disease in society, increasing the risk of diabetes, cardiovascular and liver diseases. Inadequate energy balance resulting from excessive energy intake and insufficient physical activity (PA) is one of the main factors contributing to the incidence of obesity and the development of metabolic syndrome (MetS). Treatment options for obesity include lifestyle modifications, pharmacotherapy and bariatric surgery, with the latter being the most effective treatment. Lifestyle interventions involving increased PA and reduced caloric intake improve metabolic outcomes. Early implementation of exercise leads to improved physical fitness, better glycemic control and lipid profile. Undertaking systematic PA is associated with better quality of life, improves insulin sensitivity, causes additional weight loss, reduces its adverse effects on bone mass and results in better body composition. In this narrative review we summarized the current state of knowledge on the impact of PA on the components of MetS and the latest recommendations for PA in patients with MetS.

Multicomponent and power training with elastic bands improve metabolic and inflammatory parameters, body composition and anthropometry, and physical function in older women with metabolic syndrome: A 20-week randomized, controlled trial

PURPOSE

This study aimed to explore the effects of 20 weeks of multicomponent or power training with elastic bands (EBs) on metabolic and inflammatory blood parameters, body composition, anthropometry, and physical function in older women with metabolic syndrome (MS).

METHODS

Ninety participants were randomly assigned to a multicomponent (MCG; n = 30), power (PG; n = 30), or a control group (CG; n = 30). The MCG performed balance, slow-speed strength, and aerobic training, twice per week. The PG completed a high-speed resistance training program twice per week, composed of three to four sets of ten repetitions of six overall body exercises at a perceived rating of effort for the first repetition of 3-4 on the OMNI-Resistance Exercise Scale EB. MS-related variables (glucose, triglycerides, and waist circumference) and cardiometabolic risk factors (high-density lipoprotein [HDL], glycosylated hemoglobin, total cholesterol, low-density lipoprotein cholesterol [LDL], C-reactive protein, and anthropometric profile) were assessed. Physical function was evaluated through balance, strength, and mobility tests.

RESULTS

An analysis of variance revealed that both training groups similarly improved most glycemic and lipidic profile parameters (p ≤ 0.006; d ≥ 0.46), body composition and anthropometry (p < 0.001; d ≥ 0.41), and physical function (p ≤ 0.005; d ≥ 0.69). Opposed to the PG, the MCG improved balance (p < 0.001; d = 0.96) and decreased the inflammatory status by downregulating C-reactive protein (p = 0.003; d = 0.47). On the other hand, the PG exhibited improvements in handgrip strength (p = 0.006; d = 0.48), while the MCG did not.

CONCLUSION

Therefore, multicomponent and power training with EBs are plausible strategies for improving the cardiometabolic health status and physical function in older women with MS.

Resistance training as a tool for changing muscle mass and frailty status in sarcopenic older women: a quasi-experimental study

ABSTRACT Frailty and sarcopenia are geriatric syndromes highly prevalent, complex, and hard to diagnose and treat. The literature still lacks a consensus on which resistance training program is better for older people, especially when considering frailty status and sarcopenia. We aimed to evaluate the effectiveness of a progressive resistance training program on muscle mass and frailty status in older sarcopenic women. This study included 18 community-dwelling sarcopenic women aged 65 or older enrolled in the progressive resistance training program. The intervention was based on 75% of each subject’s maximum repetition test (3 times/week, for 12 weeks). Before the intervention, 16.7% were frail, and 61.1% were pre-frail; after the intervention, 5.6% were frail, and 50% were pre-frail. The result shows that the intervention reduced frailty status and increased muscle mass (p=0.01). Hence, after the intervention, we observed both a decrease in frailty and a positive change in function, since the percentage of robust women increased twice (p=0.01). We conclude that the progressive resistance training program might be the best strategy to prevent frailty and sarcopenia. Therefore, we suggest using weight resistance training in daily clinical practice to improve muscle mass and decrease frailty status in sarcopenic women.

Association between physical activity & sedentary time on frailty status in males and females living with diabetes mellitus: A cross-sectional analysis

BACKGROUND

Physical activity (PA) is a cornerstone for the prevention and the treatment of diabetes mellitus (DM) and frailty. However, no consensus exists on which intensities and types of PA are associated with frailty status among individuals living with DM. To investigate the association between different intensities and types of PA on frailty status in males and females living with DM.

METHODS

A cross-sectional analysis of the 2003-2006 cycles from the National Health and Nutrition Examination Survey (NHANES) was performed in 711 participants living with DM. Frailty status was measured using the 43-item deficit model and DM was self-reported. Weekly PA levels were measured by accelerometer, while resistance training (RT) was measured via questionnaire. Linear and logistic regressions were performed to investigate the associations between different intensities and types of PA and frailty status.

RESULTS

Total time spent performing light PA was associated with a better frailty status in males (ß - 0.041 ± 0.012; p < 0.001) and females (ß - 0.070 ± 0.010; p < 0.0001), while total moderate-to-vigorous PA (MVPA) was associated with a better frailty status in females only (ß-0.235 ± 0.061; p < 0.05). However, once fully adjusted, the different intensities and types of PA were associated more with frailty status for female. When investigating whether different intensities and types of PA were associated with being considered frail, total time spent at MVPA and light PA were associated with higher odds along with total sedentary time for female (all p < 0.01).

CONCLUSION

Each minute engaged in PA was associated with a better frailty status in males and females living with DM, although RT does not appear associated with a better frailty status in adults with DM. Replacing sedentary time with PA is important, especially for females living with DM to have a better frailty status. These results are important as they provide insights into the prevention and the management of frailty in individuals living with DM.

High-Intensity Interval Training in Older Adults: a Scoping Review

High-intensity interval training (HIIT) is an increasingly popular form of aerobic exercise which includes bouts of high-intensity exercise interspersed with periods of rest. The health benefits, risks, and optimal design of HIIT are still unclear. Further, most research on HIIT has been done in young and middle-aged adults, and as such, the tolerability and effects in senior populations are less well-known. The purpose of this scoping review was to characterize HIIT research that has been done in older adults including protocols, feasibility, and safety and to identify gaps in the current knowledge. Five databases were searched with variations of the terms, "high-intensity interval training" and "older adults" for experimental or quasi-experimental studies published in or after 2009. Studies were included if they had a treatment group with a mean age of 65 years or older who did HIIT, exclusively. Of 4644 papers identified, 69 met the inclusion criteria. The average duration of training was 7.9 (7.0) weeks (mean [SD]) and protocols ranged widely. The average sample size was 47.0 (65.2) subjects (mean [SD]). Healthy populations were the most studied group (n = 30), followed by subjects with cardiovascular (n = 12) or cardiac disease (n = 9), metabolic dysfunction (n = 8), and others (n = 10). The most common primary outcomes included changes in cardiorespiratory fitness (such as VO2peak) as well as feasibility and safety of the protocols as measured by the number of participant dropouts, adverse events, and compliance rate. HIIT protocols were diverse but were generally well-tolerated and may confer many health advantages to older adults. Larger studies and more research in clinical populations most representative of older adults are needed to further evaluate the clinical effects of HIIT in these groups.

Effects of concurrent aerobic and resistance exercise in frail and pre-frail older adults: A randomized trial of supervised versus home-based programs

BACKGROUND

This study aimed to investigate the effects of supervised and home-based exercise programs on older people with frailty or pre-frailty.

METHODS

A total of 146 community-dwelling participants aged 65 and older who were prefrail or frail were randomly allocated into supervised exercise (N = 74) and home exercise (N = 72) groups. The 3-month supervised exercise training consisted of 3 exercise sessions per week, was performed at a hospital and supervised by a physical therapist. Home exercise participants took instructions on exercise and illustrated exercise handouts. The baseline and 3-month follow-up measurements included body composition, strength of selected upper and lower limb muscle groups, grip and leg press strengths, and five physical performance tests. Mixed-model repeated-measures analysis was applied to determine whether two groups differ in terms of changes before and after the intervention and to compare within-group improvements.

RESULTS

After 3 months of supervised or home-based exercise, the average number of frailty criteria met and fat percentage decreased significantly. Strength of knee extensors, knee flexors and leg press improved significantly in supervised exercise group. In home-based exercise group, the strength of all muscle groups tested improved significantly, except for leg press strength. Walking speed improved in both groups, and timed-up-and-go and timed chair rise tests improved significantly only in supervised exercise group.

CONCLUSIONS

Three-month supervised or home-based exercise improved walking speed and strength of the limb muscles. Supervised group showed more improvements in the physical performance tests compared with home-based exercise group.

Testosterone therapy induces molecular programming augmenting physiological adaptations to resistance exercise in older men

BACKGROUND

The andropause is associated with declines in serum testosterone (T), loss of muscle mass (sarcopenia), and frailty. Two major interventions purported to offset sarcopenia are anabolic steroid therapies and resistance exercise training (RET). Nonetheless, the efficacy and physiological and molecular impacts of T therapy adjuvant to short-term RET remain poorly defined.

METHODS

Eighteen non-hypogonadal healthy older men, 65-75 years, were assigned in a random double-blinded fashion to receive, biweekly, either placebo (P, saline, n = 9) or T (Sustanon 250 mg, n = 9) injections over 6 week whole-body RET (three sets of 8-10 repetitions at 80% one-repetition maximum). Subjects underwent dual-energy X-ray absorptiometry, ultrasound of vastus lateralis (VL) muscle architecture, and knee extensor isometric muscle force tests; VL muscle biopsies were taken to quantify myogenic/anabolic gene expression, anabolic signalling, muscle protein synthesis (D₂ O), and breakdown (extrapolated).

RESULTS

Testosterone adjuvant to RET augmented total fat-free mass (P=0.007), legs fat-free mass (P=0.02), and appendicular fat-free mass (P=0.001) gains while decreasing total fat mass (P=0.02). Augmentations in VL muscle thickness, fascicle length, and quadriceps cross-section area with RET occured to a greater extent in T (P < 0.05). Sum strength (P=0.0009) and maximal voluntary contract (e.g. knee extension at 70°) (P=0.002) increased significantly more in the T group. Mechanistically, both muscle protein synthesis rates (T: 2.13 ± 0.21%·day^-1 vs. P: 1.34 ± 0.13%·day^-1 , P=0.0009) and absolute breakdown rates (T: 140.2 ± 15.8 g·day^-1 vs. P: 90.2 ± 11.7 g·day^-1 , P=0.02) were elevated with T therapy, which led to higher net turnover and protein accretion in the T group (T: 8.3 ± 1.4 g·day^-1 vs. P: 1.9 ± 1.2 g·day^-1 , P=0.004). Increases in ribosomal biogenesis (RNA:DNA ratio); mRNA expression relating to T metabolism (androgen receptor: 1.4-fold; Srd5a1: 1.6-fold; AKR1C3: 2.1-fold; and HSD17β3: two-fold); insulin-like growth factor (IGF)-1 signalling [IGF-1Ea (3.5-fold) and IGF-1Ec (three-fold)] and myogenic regulatory factors; and the activity of anabolic signalling (e.g. mTOR, AKT, and RPS6; P < 0.05) were all up-regulated with T therapy. Only T up-regulated mitochondrial citrate synthase activity (P=0.03) and transcription factor A (1.41 ± 0.2-fold, P=0.0002), in addition to peroxisome proliferator-activated receptor-γ co-activator 1-α mRNA (1.19 ± 0.21-fold, P=0.037).

CONCLUSIONS

Administration of T adjuvant to RET enhanced skeletal muscle mass and performance, while up-regulating myogenic gene programming, myocellular translational efficiency and capacity, collectively resulting in higher protein turnover, and net protein accretion. T coupled with RET is an effective short-term intervention to improve muscle mass/function in older non-hypogonadal men.

Movement velocity can be used to estimate the relative load during the bench press and leg press exercises in older women

Background

Movement velocity has been proposed as an effective tool to prescribe the load during resistance training in young healthy adults. This study aimed to elucidate whether movement velocity could also be used to estimate the relative load (i.e., % of the one-repetition maximum (1RM)) in older women.

Methods

A total of 22 older women (age = 68.2 ± 3.6 years, bench press 1RM = 22.3 ± 4.7 kg, leg press 1RM = 114.6 ± 15.9 kg) performed an incremental loading test during the free-weight bench press and the leg press exercises on two separate sessions. The mean velocity (MV) was collected with a linear position transducer.

Results

A strong linear relationship between MV and the relative load was observed for the bench press (%1RM = −130.4 MV + 119.3; r² = 0.827, standard error of the estimate (SEE) = 6.10%1RM, p < 0.001) and leg press exercises (%1RM = −158.3 MV + 131.4; r² = 0.913, SEE = 5.63%1RM, p < 0.001). No significant differences were observed between the bench press and leg press exercises for the MV attained against light-medium relative loads (≤70%1RM), while the MV associated with heavy loads (≥80%1RM) was significantly higher for the leg press.

Conclusions

These results suggest that the monitoring of MV could be useful to prescribe the loads during resistance training in older women. However, it should be noted that the MV associated with a given %1RM is significantly lower in older women compared to young healthy individuals.

Sarcopenic obesity predicts nonremission of late-life depression

BACKGROUND/OBJECTIVES

Aging-related physiological changes like metabolic dysregulation and physical frailty are associated with depression and worsen its prognosis. Since central obesity is a key component of the metabolic syndrome and sarcopenia of physical frailty, we examined the association of sarcopenic obesity with depression cross-sectional and over time.

METHODS

Cohort study of depressed patients and a nondepressed comparison group.

SETTING

Primary and secondary mental health care.

PARTICIPANTS

Three hundred seventy-eight older (≥60 y) depressed patients of which 285 were followed up at 2 years and 132 nondepressed persons participating in the Netherlands Study of Depression in Older (NESDO) persons.

MEASUREMENTS

Sarcopenic obesity was based on predefined cutoffs for both maximum handgrip strength (assessed with a dynamometer) and waist circumference (dichotomous) as well as the product term of handgrip strength by waist circumference (dimensional). Depressive disorder according to DSM-IV-TR criteria was assessed with fully structured psychiatric interview at baseline and 2-year follow-up.

RESULTS

Sarcopenic obesity was more prevalent among depressed patients compared with nondepressed participants (18.9% versus 10.7%, P = 0.030). Neither the dichotomous nor dimensional operationalization of sarcopenic obesity was associated with baseline depressive disorder when adjusted for covariates. Nonetheless, among depressed patients, logistic regression showed that the interaction of handgrip strength by waist circumference was associated with remitted depression at 2-year follow-up (P = 0.044). Only among patients with a low handgrip strength, a higher waist circumference predicted nonremission.

CONCLUSION

Among depressed patients, sarcopenic obesity predicts nonremission of depression. Therefore, combined exercise and nutritional interventions might be effective for depressed patients with sarcopenic obesity.

Strength training as superior, dose-dependent and safe prevention of acute and overuse sports injuries: a systematic review, qualitative analysis and meta-analysis

Objective

This review aims to analyse strength training-based sports injury prevention randomised controlled trials (RCT) and present best evidence recommendations for athletes and future research. A priori PROSPERO registration; CRD42015006970.

Design

Systematic review, qualitative analysis and meta-analysis. Sorting of studies and quality assessments were performed by two independent authors. Qualitative analyses, relative risk (RR) estimate with robustness and strength of evidence tests, formal tests of publication bias and post-hoc meta-regression were performed.

Data sources

PubMed, Embase, Web of Science and SPORTDiscus were searched to July 2017.

Eligibility criteria for selecting studies

RCTs on strength training exercises as primary prevention of sports injuries.

Results

Six studies analysed five different interventions with four distinct outcomes. 7738 participants aged 12–40 years were included and sustained 177 acute or overuse injuries. Studies were published in 2003–2016, five from Europe and one from Africa. Cluster-adjusted intention-to-treat analysis established RR 0.338 (0.238–0.480). The result was consistent across robustness tests and strength of evidence was high. A 10% increase in strength training volume reduced the risk of injury by more than four percentage points. Formal tests found no publication bias.

Conclusion

The included studies were generally well designed and executed, had high compliance rates, were safe, and attained consistently favourable results across four different acute and overuse injury outcomes despite considerable differences in populations and interventions. Increasing strength training volume and intensity were associated with sports injury risk reduction. Three characteristically different approaches to prevention mechanisms were identified and incorporated into contemporary strength training recommendations.

Effect of a resistance exercise program for sarcopenic elderly women: quasi-experimental study

Abstract Introduction: Resistance training is quoted as one of the best pathways to manage sarcopenia and progressive resistance training is supposed to improve muscle mass, strength and performance in older adults. Objective: The aim was to examine the impact of a progressive resistance exercise program (PREP) on muscle and function performance in sarcopenic community-dwelling elder women. Methods: Quasi-experimental study (pre - post intervention). Participated 18 sarcopenic community-dwelling elder women (65 years or older). PREP based on 75% of the participant’s maximum load (12/wk, 3 times/wk). Main outcome measures: muscle strength of knee extensors (isokinetic dynamometry), muscle mass (dual-x ray absorptiometry - DXA), functional performance (Short Physical Performance Battery - SPPB). Paired t-test was used to evaluate differences pre and post intervention. Results: Improvements on power (p = 0.01) and peak torque (p = 0.01) were observed when measured by the isokinetic dynamometer at low speed (60º/s). Improvements on DXA (pre PREP: 5.49 kg/m2 vs. post PREP: 6.01 kg/m2; p = 0.03) and SPPB scores (pre PREP: 9.06 vs. post PREP: 10.28; p = 0.01) were also observed. Conclusion: The PREP was able to improve muscle and functional performance in sarcopenic community-dwelling elder women. This program should be considered in clinical practice.

Weight bearing exercise can elicit similar peak muscle activation as medium-high intensity resistance exercise in elderly women

PURPOSE

To assess whether stepping-based weight bearing exercise (WBE) can elicit peak activation of upper leg muscles similar to resistance exercise (RE) at an intensity required to induce strength gains in elderly women.

METHODS

Muscular activation of several upper leg muscles was measured during RE and WBE in a cohort of 19 healthy elderly women (69.3 ± 3.4 years). WBE consisted of forward and lateral stepping with step heights of 10, 20 and 30 cm. Muscular activation was compared to 60% of one-repetition maximum (1-RM) of congruent RE.

RESULTS

Peak activation during WBE was higher than RE at 60% 1-RM during forward and lateral stepping in vastus lateralis starting at 20 cm (p = 0.049 and p = 0.001), and biceps femoris at 30 cm step height (p = 0.024 and p = 0.030). Gluteus maximus peak activation matched RE at 60% 1-RM at 20 and 30 cm step height regardless of step direction (p ≥ 0.077). Peak activation of the rectus femoris and gluteus medius matched RE activation at 60% 1-RM during lateral stepping at 30 cm (p = 0.355 and p = 0.243, respectively) but not during forward stepping. WBE did not induce similar activation as RE in the semitendinosus.

CONCLUSION

In WBE, most upper leg muscles were recruited at an equal or higher intensity than in RE at 60% 1-RM. Lateral stepping at 30 cm step height showed the highest training potential of all WBE's applied.

Prevalence and Incidence of Frailty in Community-Dwelling Older People: Beijing Longitudinal Study of Aging II

OBJECTIVES

To estimate the prevalence and incidence of frailty and evaluate the effect of frailty on adverse outcomes in Chinese elderly adults.

DESIGN

Secondary analysis of prospective cohort study.

SETTING

Community in Beijing, China.

PARTICIPANTS

Individuals aged 55 and older (N = 10,039).

MEASUREMENTS

A Frailty Index (FI) was derived from 34 items using Rockwood's cumulative deficits method. A FI of 0.25 or greater indicated frailty. The clinical outcome was evaluated using a composite variable of any of the following adverse events: falls, hospitalization, activity of daily living disability, and death.

RESULTS

The overall crude prevalence of frailty was 12.3% (95% confidence interval (CI) = 11.7-13.0%), and the standardized prevalence was 9.1% (95% CI = 8.6-9.7%). The crude incidence was 13.0% (95% CI = 12.2-13.9%), and the standardized incidence 10.8% (95% CI = 10.0-11.6%). Prevalence and incidence were significantly greater with age (P for trend < .001) and greater in women (P < .001) and urban residents (P < .001). Participants with lower education and having three or more diseases and taking four or more medications daily were more likely to develop frailty over follow-up (all P < .05). After adjusting for age, number of diseases, and smoking at baseline, the risk of any adverse event in 1 year in the frail group was 58% higher than in the nonfrail group (adjusted odds ratio = 1.58, 95% CI = 1.30-1.93, P < .001).

CONCLUSION

A feasible FI that can be used in routine medical evaluation in a primary care setting was developed, and a 12.3% prevalence and a 13% incidence of frailty was demonstrated in community-dwelling Chinese older adults. Frailty is more common for urban and female residents in the oldest old group. Being frail significantly predicts geriatric adverse outcomes, indicating the importance of early screening and intervention in frail individuals in primary care.

Femoral Bone Marrow Insulin Sensitivity Is Increased by Resistance Training in Elderly Female Offspring of Overweight and Obese Mothers

Bone marrow insulin sensitivity may be an important factor for bone health in addition to bone mineral density especially in insulin resistant conditions. First we aimed to study if prenatal maternal obesity plays a role in determining bone marrow insulin sensitivity in elderly female offspring. Secondly we studied if a four-month individualized resistance training intervention increases bone marrow insulin sensitivity in elderly female offspring and whether this possible positive outcome is regulated by the offspring’s mother’s obesity status. 37 frail elderly females (mean age 71.9 ± 3.1 years) of which 20 were offspring of lean/normal-weight mothers (OLM, maternal BMI ≤ 26.3 kg/m2) and 17 were offspring of obese/overweight mothers (OOM, maternal BMI ≥ 28.1 kg/m2) were studied before and after a four-month individualized resistance training intervention. Nine age- and sex-matched non-frail controls (maternal BMI ≤ 26.3 kg/m2) were studied at baseline. Femoral bone marrow (FBM) and vertebral bone marrow (VBM) insulin sensitivity were measured using [18F]fluoro-2-deoxy-D-glucose positron emission tomography with computer tomography under hyperinsulinemic euglycemic clamp. We found that bone marrow insulin sensitivity was not related to maternal obesity status but FBM insulin sensitivity correlated with whole body insulin sensitivity (R = 0.487, p = 0.001). A four-month resistance training intervention increased FBM insulin sensitivity by 47% (p = 0.006) only in OOM, while VBM insulin sensitivity remained unchanged regardless of the maternal obesity status. In conclusion, FBM and VBM glucose metabolism reacts differently to a four-month resistance training intervention in elderly women according to their maternal obesity status.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01931540.

Irisin promotes osteoblast proliferation and differentiation via activating the MAP kinase signaling pathways

Physical exercise is able to improve skeletal health. However, the mechanisms are poorly known. Irisin, a novel exercise-induced myokine, secreted by skeletal muscle in response to exercise, have been shown to mediate beneficial effects of exercise in many disorders. In the current study, we demonstrated that irisin promotes osteoblast proliferation, and increases the expression of osteoblastic transcription regulators, such as Runt-related transcription factor-2, osterix/sp7; and osteoblast differentiation markers, including alkaline phosphatase, collagen type 1 alpha-1, osteocalcin, and osteopontin in vitro. Irisin also increase ALP activity and calcium deposition in cultured osteoblast. These osteogenic effects were mediated by activating the p38 mitogen-activated protein kinase (p-p38 MAPK) and extracellular signal-regulated kinase (ERK). Inhibition of p38 MAPK by SB023580 or pERK by U0126 abolished the proliferation and up-regulatory effects of irisin on Runx₂ expression and ALP activity. Together our observation suggest that irisin directly targets osteoblast, promoting osteoblast proliferation and differentiation via activating P38/ERK MAP kinase signaling cascades in vitro. Whether irisin can be utilized as the therapeutic agents for osteopenia and osteoporosis is worth to be further pursued.

Voluntary Aerobic Exercise Reverses Frailty in Old Mice

Frailty is a major cause of disability and loss of independence in the elderly. Using clinically relevant criteria from our previously established mouse frailty index, we investigated the effects of aerobic exercise on frailty in male C57BL/6 mice. In order to measure the effect of treatment on the individual animals, we constructed a composite score, the Frailty Intervention Assessment Value. We hypothesized voluntary aerobic exercise would improve individual criteria and reverse or prevent frailty in the old mice. Five adult and 11 old mice (6 and 28+ months, respectively) were housed individually in cages with running wheels for 4 weeks. Controls (adult, n = 5 and old, n = 17) were housed without wheels. Inverted cling grip and rotarod tests were performed pre- and postintervention. Hind limb muscles were used for biochemical analysis and contractility experiments. We conclude that the exercise stimulus reversed frailty and was sufficient to maintain or improve functional performance in old mice, as well as to produce measurable morphological changes. In addition, the Frailty Intervention Assessment Value proved to be a valuable tool with increased power to detect treatment effects and to examine the intervention efficacy at the level of the individual mouse.

Progressive resistance strength training and the related injuries in older adults: the susceptibility of the shoulder

The benefits of progressive resistance training (PRT) among the older adults are evident, especially in the prevention of sarcopenia and improving muscle strength, which reverse the age-related loss of functional ability. However, PRT carries some risk, particularly when participants are older adults with a certain degree of muscle weakness. The purpose of this article is to discuss the PRT-related injuries, and present an overview of documented shoulder injuries among the elderly, discerning possible mechanisms of injury and risk factors. A literature search was conducted in the PUBMED database to identify the relevant literature using combinations of keywords: strength-training injuries, resistance-training injuries, sports injuries in the elderly, shoulder complex, shoulder injury, and shoulder disorder. Acute and chronic injuries attributed to PRT have been cited in the epidemiological literature. The shoulder complex, has been alluded to as one of the most prevalent regions of injury, particularly in exercises that place the arm extended above the head and posterior to the trunk. However, the risk for injuries appears to be higher for testing than for training itself. One-repetition maximum strength testing may result in a greater injury risk. This technique, though acceptable, needs additional precautions in inexperience older adults to prevent injury. Thus, the best treatment for PRT age-related injuries is prevention. Appropriate and individualized training programs, the use of safe equipment, careful warming up and cooling down, correct range of motion, progressive intensity training, cardiovascular and musculoskeletal fitness are essential aspects of injury prevention among the elderly.

Potential benefits of exercise on blood pressure and vascular function

Physical activity seems to enhance cardiovascular fitness during the course of the lifecycle, improve blood pressure, and is associated with decreased prevalence of hypertension and coronary heart disease. It may also delay or prevent age-related increases in arterial stiffness. It is unclear if specific exercise types (aerobic, resistance, or combination) have a better effect on blood pressure and vascular function. This review was written based on previous original articles, systematic reviews, and meta-analyses indexed on PubMed from years 1975 to 2012 to identify studies on different types of exercise and the associations or effects on blood pressure and vascular function. In summary, aerobic exercise (30 to 40 minutes of training at 60% to 85% of predicted maximal heart rate, most days of the week) appears to significantly improve blood pressure and reduce augmentation index. Resistance training (three to four sets of eight to 12 repetitions at 10 repetition maximum, 3 days a week) appears to significantly improve blood pressure, whereas combination exercise training (15 minutes of aerobic and 15 minutes of resistance, 5 days a week) is beneficial to vascular function, but at a lower scale. Aerobic exercise seems to better benefit blood pressure and vascular function.

Effects of different types of acute and chronic (training) exercise on glycaemic control in type 1 diabetes mellitus: a meta-analysis

OBJECTIVE

Exercise has been accepted and generally recommended for the management of type 1 diabetes mellitus (T1D) and for improving the overall quality of life in affected individuals. This meta-analysis was conducted to determine the overall effects of exercise (acute bouts of exercise and chronic exercise [or training]) on acute and chronic glycaemic control in patients with T1D, the effects of different types of exercise on glycaemic control and which conditions are required to obtain these positive effects.

METHODS

PubMed, ISI Web of Knowledge and SPORTDiscus™ were consulted to identify studies on T1D and exercise. Cohen's d statistics were used for calculating mean effect sizes (ES) as follows: small d = 0.3, medium d = 0.5 and large d = 0.8. Ninety-five percent confidence intervals (95% CIs) were used to establish the significance of our findings.

RESULTS

From a total of 937 studies, 33 that met the inclusion criteria were selected. Nine studies were used to calculate the ES of a single bout of aerobic exercise; 13 studies to calculate the ES of aerobic training; 2 studies to calculate the ES of strength training; 4 studies to calculate the ES of combined (aerobic and strength) training and 6 studies to calculate the ES of high-intensity exercise (HIE) and training. ES for exercise on acute glycaemic control were large, while they were small for chronic glycaemic control. Aerobic exercise, resistance exercise, mixed exercise (aerobic combined with resistance training) and HIE acutely decreased blood glucose levels. To prevent late-onset hypoglycaemic episodes, the use of single bouts of sprints into an aerobic exercise can be recommended. This meta-analysis also showed that a regular exercise training programme has a significant effect on acute and chronic glycaemic control, although not all exercise forms showed significant results. Specifically, aerobic training is a favourable tool for decreasing chronic glycaemic control, while resistance training, mixed and HIE did not significantly improve chronic glycaemic control. Although, this meta-analysis showed there was a tendency for improvement in glycaemic control due to resistance training or resistance training combined with endurance training, there were not enough studies and/or subjects to confirm this statistically.

CONCLUSIONS

Based on this meta-analysis, we can conclude that the addition of brief bouts of high-intensity, sprint-type exercise to aerobic exercise can minimize the risk of sustaining a hypoglycaemic episode. We can also conclude that only regular aerobic training will improve the glycated haemoglobin level of a patient with T1D.

Effects of different types of acute and chronic (training) exercise on glycaemic control in type 1 diabetes mellitus: a meta-analysis

OBJECTIVE

Exercise has been accepted and generally recommended for the management of type 1 diabetes mellitus (T1D) and for improving the overall quality of life in affected individuals. This meta-analysis was conducted to determine the overall effects of exercise (acute bouts of exercise and chronic exercise [or training]) on acute and chronic glycaemic control in patients with T1D, the effects of different types of exercise on glycaemic control and which conditions are required to obtain these positive effects.

METHODS

PubMed, ISI Web of Knowledge and SPORTDiscus™ were consulted to identify studies on T1D and exercise. Cohen's d statistics were used for calculating mean effect sizes (ES) as follows: small d = 0.3, medium d = 0.5 and large d = 0.8. Ninety-five percent confidence intervals (95% CIs) were used to establish the significance of our findings.

RESULTS

From a total of 937 studies, 33 that met the inclusion criteria were selected. Nine studies were used to calculate the ES of a single bout of aerobic exercise; 13 studies to calculate the ES of aerobic training; 2 studies to calculate the ES of strength training; 4 studies to calculate the ES of combined (aerobic and strength) training and 6 studies to calculate the ES of high-intensity exercise (HIE) and training. ES for exercise on acute glycaemic control were large, while they were small for chronic glycaemic control. Aerobic exercise, resistance exercise, mixed exercise (aerobic combined with resistance training) and HIE acutely decreased blood glucose levels. To prevent late-onset hypoglycaemic episodes, the use of single bouts of sprints into an aerobic exercise can be recommended. This meta-analysis also showed that a regular exercise training programme has a significant effect on acute and chronic glycaemic control, although not all exercise forms showed significant results. Specifically, aerobic training is a favourable tool for decreasing chronic glycaemic control, while resistance training, mixed and HIE did not significantly improve chronic glycaemic control. Although, this meta-analysis showed there was a tendency for improvement in glycaemic control due to resistance training or resistance training combined with endurance training, there were not enough studies and/or subjects to confirm this statistically.

CONCLUSIONS

Based on this meta-analysis, we can conclude that the addition of brief bouts of high-intensity, sprint-type exercise to aerobic exercise can minimize the risk of sustaining a hypoglycaemic episode. We can also conclude that only regular aerobic training will improve the glycated haemoglobin level of a patient with T1D.

Physical Activity and the Science of Successful Aging

Successful aging encompasses more than just the prevention of disease and disability; the truly well-lived life is demonstrated by a sense of vitality and independence, freedom from bodily pain, and the continued involvement in meaningful activities. While physical inactivity and sedentary behaviors accelerate the aging process, deliberate exercise and other forms of activity delay and/or prevent the onset of age-related pathologies such as frailty, osteoporosis, sarcopenia, and cardiovascular disease. This review surveys the evidence that supports the position that physical activity is a necessary component for the development and maintenance of the physiological resources that are foundational to physical and cognitive functioning and ‘living well’ in one's later years.

Promoting access to innovation for frail old persons. IAGG (International Association of Gerontology and Geriatrics), WHO (World Health Organization) and SFGG (Société Française de Gériatrie et de Gérontologie) Workshop--Athens January 20-21, 2012

Frailty tends to be considered as a major risk for adverse outcomes in older persons, but some important aspects remain matter of debate.

OBJECTIVES

The purpose of this paper is to present expert's positions on the main aspects of the frailty syndrome in the older persons.

PARTICIPANTS

Workshop organized by International Association of Gerontology and Geriatrics (IAGG), World Health Organization (WHO) and Société Française de Gériatrie et de Gérontologie (SFGG).

RESULTS

Frailty is widely recognized as an important risk factor for adverse health outcomes in older persons. This can be of particular value in evaluating non-disabled older persons with chronic diseases but today no operational definition has been established. Nutritional status, mobility, activity, strength, endurance, cognition, and mood have been proposed as markers of frailty. Another approach calculates a multidimensional score ranging from "very fit" to "severely frail", but it is difficult to apply into the medical practice. Frailty appears to be secondary to multiple conditions using multiple pathways leading to a vulnerability to a stressor. Biological (inflammation, loss of hormones), clinical (sarcopenia, osteoporosis etc.), as well as social factors (isolation, financial situation) are involved in the vulnerability process. In clinical practice, detection of frailty is of major interest in oncology because of the high prevalence of cancer in older persons and the bad tolerance of the drug therapies. Presence of frailty should also be taken into account in the definition of the cardiovascular risks in the older population. The experts of the workshop have listed the points reached an agreement and those must to be a priority for improving understanding and use of frailty syndrome in practice.

CONCLUSION

Frailty in older adults is a syndrome corresponding to a vulnerability to a stressor. Diagnostic tools have been developed but none can integrate at the same time the large spectrum of factors and the simplicity asked by the clinical practice. An agreement with an international common definition is necessary to develop screening and to reduce the morbidity in older persons.