Determining the Importance of Meeting Muscle-Strengthening Activity Guidelines: Is the Behavior or the Outcome of the Behavior (Strength) a More Important Determinant of All-Cause Mortality?

Comparative efficacy of exercise modalities for general risk factors, renal function, and physical function in non-dialysis chronic kidney disease patients: a systematic review and network meta-analysis

BACKGROUND

Exercise therapy can effectively manage chronic kidney disease (CKD) risk factors and improve renal function and physical fitness, but the challenge lies in choosing the right exercise type tailored to patients' condition.

METHODS

An electronic search of databases including PubMed, The Cochrane Library, EMBASE, Web of Science, VIP, WanFang, and CNKI was performed. The random effects model was used. Mean difference was employed as the effect size for continuous variables, with 95% confidence interval (CI) provided.

RESULTS

A total of 36 RCTs were included in this study. Compared to conventional therapy (CT), the combination of three exercise therapies with CT resulted in notable benefits in enhancing six minutes walk test (6MWT) capacity, 24-h urinary protein quantity (24hUTP), systolic blood pressure (SBP), diastolic blood pressure (DBP). Resistance exercise therapy (RT) + CT were more effective than CT to reduce serum creatinine (Scr), body mass index (BMI), and hemoglobin A1c (HbA1c) and improve estimated glomerular filtration rate (eGFR). In terms of improving peak oxygen uptake (VO2 peak), only two exercise modalities were involved, aerobic exercise therapy (AT) and combined (Resistance-Aerobic) exercise therapy (CBT), both of which were more efficacious than CT. The efficacy ranking overall demonstrated clear benefits for RT in enhancing eGFR and 6MWT, decreasing Scr, BMI, SBP, DBP, and HbA1c, while AT was more suitable for boosting VO2 peak, and CBT had greater potential for reducing 24hUTP.

CONSLUSIONS

Exercise therapy combined with CT offers significant advantages over CT in many cases, but no single exercise modality is universally effective for all indicators.

Exercise instructors are not consistently implementing the strength component of the UK chief medical officers' physical activity guidelines in their exercise prescription for older adults

Strength training recommendations have been embedded within the UK's Chief Medical Officers' physical activity guidelines since 2011. There is limited evidence that these recommendations are used by exercise instructors in the community to underpin strength training prescription in the older adult population. This study aimed to explore exercise instructors' awareness and utilisation of the guidelines when prescribing strength training to older adults. Fifteen exercise instructors working with older adults in the UK participated in one online interview. A general inductive approach was conducted and thematic analysis allowed for major themes to be identified from the raw data. We found that most exercise instructors (n = 9), but not all (n = 6), were aware of the guidelines. Only one instructor (n = 1) had reportedly implemented the guidelines into their practice; other instructors reported that the guidelines were irrelevant. Instead, each of the instructors had their preferred sources of information that they relied on to underpin their exercise prescription, and each had their own interpretation of 'evidence-based strength training.' This individualised interpretation resulted in exceptionally varied prescription in the community and does not necessarily align with the progressive, evidence-based prescription known to build muscular strength. We suggest that (i) more detail on how to build muscular strength be embedded within the guidelines, (ii) a handbook on how to implement the guidelines be made available, (iii) theoretical and practical teaching materials and courses be updated, and/or (iv) a re-(education) of exercise instructors already in the field may be necessary to bring about a consistent, evidence-based strength prescription necessary for the best possible health and longevity outcomes for our ageing population.

'Get Healthy!' physical activity and healthy eating intervention for adults with intellectual disability: results from the feasibility pilot

BACKGROUND

People with intellectual disabilities (ID) experience high rates of lifestyle related morbidities, in part due to lack of access to tailored health promotion programmes. This study aimed to assess the feasibility and preliminary efficacy of a tailored healthy lifestyle intervention, Get Healthy!

METHODS

Get Healthy! is a 12-week physical activity and healthy eating programme designed to address lifestyle-related risks for adults with mild-moderate ID. The feasibility pilot was designed to assess subjective participant experience and programme feasibility across: recruitment and screening, retention, session attendance and engagement, adverse events, and practicality and reliability of outcome procedures. Exploratory programme efficacy was assessed across the following measures: anthropometry (body mass index, weight, waist circumference), cardiovascular fitness, physical strength, dietary intake, healthy literacy, and quality of life.

RESULTS

Six participants with moderate ID and two carer participants completed the feasibility trial, representing a 100% retention rate. Qualitative data indicated the programme was well received. Participants with ID attended 75% of sessions offered and displayed a high level of engagement in sessions attended (91% mean engagement score). While most data collection procedures were feasible to implement, several measures were either not feasible for our participants, or required a higher level of support to implement than was provided in the existing trial protocol. Participants with ID displayed decreases in mean waist circumference between baseline and endpoint (95% CI: - 3.20, - 0.17 cm) and some improvements in measures of cardiovascular fitness and physical strength. No changes in weight, body mass index, or objectively measured knowledge of nutrition and exercise or quality of life were detected from baseline to programme endpoint. Dietary intake results were mixed.

DISCUSSION

The Get Healthy! programme was feasible to implement and well received by participants with moderate ID and their carers. Exploratory efficacy data indicates the programme has potential to positively impact important cardiometabolic risk factors such as waist circumference, cardiovascular fitness, and physical strength. Several of the proposed data collection instruments will require modification or replacement prior to use in a sufficiently powered efficacy trial.

TRIAL REGISTRATION

ACTRN: ACTRN12618000349246. Registered March 8th 2018-retrospectively registered, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=374497 UTN: U1111-1209-3132.

Resistance Training and Mortality Risk: A Systematic Review and Meta-Analysis

INTRODUCTION

This study aimed to systematically review and meta-analyze the relationship between resistance training and all-cause, cardiovascular disease, and cancer mortality.

METHODS

Systematic review and meta-analysis following PRISMA guidelines (International Prospective Register of Systematic Reviews Registration Number CRD42019136654) was conducted. MEDLINE (OVID), Embase, Emcare, SPORTDiscus, The Cochrane Library, and SCOPUS were searched from inception to June 6, 2021. Included studies reported resistance training as the exposure and all-cause mortality, cardiovascular disease‒specific mortality, and/or cancer-specific mortality as outcome/s. Only studies conducted among nonclinical adult populations (aged ≥18 years) and written in English were included.

RESULTS

A total of 10 studies were included in the meta-analyses. Compared with undertaking no resistance training, undertaking any amount of resistance training reduced the risk of all-cause mortality by 15% (RR of 6 studies=0.85; 95% CI=0.77, 0.93), cardiovascular disease mortality by 19% (RR of 4 studies=0.81; 95% CI=0.66, 1.00), and cancer mortality by 14% (RR of 5 studies=0.86; 95% CI=0.78, 0.95). A dose-response meta-analysis of 4 studies suggested a nonlinear relationship between resistance training and the risk of all-cause mortality. A maximum risk reduction of 27% was observed at around 60 minutes per week of resistance training (RR=0.74; 95% CI=0.64, 0.86). Mortality risk reductions diminished at higher volumes.

DISCUSSION

This systematic review and meta-analysis provides the strongest evidence to date that resistance training is associated with reduced risk of all-cause, cardiovascular disease, and cancer-specific mortality. More research is needed to determine whether any potential mortality benefits gained from resistance training diminish at higher volumes.

Resistance Training before, during, and after COVID-19 Infection: What Have We Learned So Far?

At the end of 2019, a severe acute respiratory syndrome caused by SARS-CoV-2 started a pandemic, leading to millions of deaths and many important political and social changes. Even in the absence of contamination, the mobility reduction, social distancing and closing of exercise facilities negatively affected physical activity and conditioning, which is associated with muscle atrophy, loss of muscle strength, and reductions in functional capacity. In cases of infection, it has been shown that increased physical capacity is associated with decreased hospitalization and mortality risk. Although millions of people have died from COVID-19, most contaminated individuals survived the infection, but carried different sequelae, such as the severe loss of physical function and a reduced quality of life. Among different physical exercise models that might help to prevent and treat COVID-19-related conditions, resistance training (RT) might be particularly relevant. Among its benefits, RT can be adapted to be performed in many different situations, even with limited space and equipment, and is easily adapted to an individual's characteristics and health status. The current narrative review aims to provide insights into how RT can be used in different scenarios to counteract the negative effects of COVID-19. By doing this, the authors expect to provide insights to help deal with the current pandemic and similar events the world may face in the future.

Who is meeting the strengthening physical activity guidelines by definition: A cross-sectional study of 253 423 English adults?

The current UK physical activity guidelines recommend that adults aged 19 to 65 years perform activity to strengthen muscle and bone a minimum of twice weekly. The number of adults meeting strengthening activity guidelines is lower than for aerobic activity, but estimates vary between studies partly due to differences in how muscle-strengthening activity is defined. We aimed to provide estimates for strengthening activity prevalence in English adults based on a nationally representative sample of n = 253,423 18-65-year-olds. We attempted to quantify the variation in estimates attributable to differences in the way strengthening activity is defined. Finally, we aim to provide a brief descriptive epidemiology of the factors associated with strengthening activity. Adults met guidelines for aerobic activity if they reported the activity equivalent to >150 min/week moderate-intensity exercise. Respondents met strengthening guidelines if they reported at least two bouts per week of strengthening activity. We defined strengthening activity, first, according to criteria used in the Health Survey for England (HSE). Second, we counted bouts of strengthening activities for which we could find evidence of health-related benefits (Evidence). Third, we included bouts of strengthening activity as defined in current UK physical activity guidelines (Guideline). Two-thirds (67%) of adults met guidelines for aerobic activity (69% of men, 65% of women). Less than one-third (29% of men and 24% of women) met guidelines for the HSE definition of strengthening activity. Under the Evidence definition, 16% of men and 9% of women met strengthening guidelines. Using the most-stringent definition (Guideline) just 7.3% of men and 4.1% of women achieved the recommendations for strengthening activity. We found females and older adults (50–65 years) were less likely to meet guidelines for aerobic, strengthening, and combined aerobic plus strengthening activity. The prevalence of meeting activity guidelines was lower in adults from more deprived areas (compared with the least deprived); Adults with lower academic qualifications (Level 1) were less likely to meet activity guidelines than those educated to Level 4 (Degree Level) or higher. Having a limiting disability was associated with a lower prevalence of meeting activity guidelines. Associations between socio-demographic measures and the prevalence of adults meeting activity guidelines were stronger for strengthening activity than for aerobic 51(or combined aerobic plus strengthening) activity Compared with aerobic activity, fewer adults engage in strengthening activity regardless of how it is defined. The range in estimates for how many adults meet strengthening activity guidelines can be explained by variations in the definition of ‘strengthening’ that are used and the specific sports or activities identified as strengthening exercise. When strengthening activity is included, the proportion of English adults meeting current physical activity guidelines could be as high as 1 in 3 but possibly as low as just 1 in 20. A harmonized definition of strengthening activity, that is aligned with physical activity guidelines, is required to provide realistic and comparable prevalence estimates.

Muscle-strengthening activities are associated with lower risk and mortality in major non-communicable diseases: a systematic review and meta-analysis of cohort studies

OBJECTIVE

To quantify the associations between muscle-strengthening activities and the risk of non-communicable diseases and mortality in adults independent of aerobic activities.

DESIGN

Systematic review and meta-analysis of prospective cohort studies.

DATA SOURCES

MEDLINE and Embase were searched from inception to June 2021 and the reference lists of all related articles were reviewed.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Prospective cohort studies that examined the association between muscle-strengthening activities and health outcomes in adults aged ≥18 years without severe health conditions.

RESULTS

Sixteen studies met the eligibility criteria. Muscle-strengthening activities were associated with a 10-17% lower risk of all-cause mortality, cardiovascular disease (CVD), total cancer, diabetes and lung cancer. No association was found between muscle-strengthening activities and the risk of some site-specific cancers (colon, kidney, bladder and pancreatic cancers). J-shaped associations with the maximum risk reduction (approximately 10-20%) at approximately 30-60 min/week of muscle-strengthening activities were found for all-cause mortality, CVD and total cancer, whereas an L-shaped association showing a large risk reduction at up to 60 min/week of muscle-strengthening activities was observed for diabetes. Combined muscle-strengthening and aerobic activities (versus none) were associated with a lower risk of all-cause, CVD and total cancer mortality.

CONCLUSION

Muscle-strengthening activities were inversely associated with the risk of all-cause mortality and major non-communicable diseases including CVD, total cancer, diabetes and lung cancer; however, the influence of a higher volume of muscle-strengthening activities on all-cause mortality, CVD and total cancer is unclear when considering the observed J-shaped associations.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020219808.

'Snacktivity™' to increase physical activity: Time to try something different?

Evidence demonstrates that participation in regular physical activity (PA) reduces the risk of morbidity and mortality. However, current PA guidelines are focused on weekly accumulation of 150 min of moderate intensity PA as a threshold. Although recent developments of this guidance have discussed the merits of short bouts of physical activity, guidance that sets large behavioural goals for PA has not been successful in supporting the public to become sufficiently physically active and a 'one-size fits all' approach to PA guidelines may not be optimal. A complementary 'whole day' approach to PA promotion (i.e. incorporating PA throughout the day) that could motivate the population to be more physically active, is a concept we have called 'Snacktivity™'. The Snacktivity™ approach promotes small or 'bite' size bouts (e.g. 2-5 min) of PA accumulated throughout the whole day. Snacktivity™ is consistent with the small change approach which suggest that behaviour change and habit formation are best achieved through gradual building of task self-efficacy, celebrating small successes. Snacktivity™ also offers opportunities to "piggyback" on to existing behaviours/habits, using them as prompts for Snacktivity™. Moreover, small behaviour changes are easier to initiate and maintain than larger ones. A plethora of evidence supports the hypothesis that Snacktivity may be a more acceptable and effective way to help the public reach, or exceed current PA guidelines. This paper outlines the evidence to support the Snacktivity™ approach and the mechanisms by which it may increase population levels of physical activity. Future research directions for Snacktivity™ are also outlined.

Cycle ergometer training and resistance training similarly increase muscle strength in trained men

The aim of this study was to compare two different maximal intensity exercise modality training protocols of similar durations on muscle strength, cardiorespiratory fitness, and lower limb composition in recreationally trained men. Twenty-five trained men (28.9 ± 5.6 years) were randomly divided into Cycle ergometer (4 sets of 30 seconds sprints) and Leg press (4 sets of 10-12 repetitions to momentary failure). Both groups trained three times a week for 5 weeks. Before and after the training period, the participants performed a 10-repetition maximum (10RM) test for knee extension, an incremental exercise test on a treadmill for time to exhaustion (TTE) and peak oxygen consumption (V˙O_2peak) and underwent dual energy X-ray absorptiometry to assess lower limb composition. Knee extension 10RM and TTE increased in both groups with no statistically significant between group (p = 0.614 and p = 0.210). Only cycle ergometer group increased V˙O_2peak (p ₌ 0,012). For all lower limb composition outcomes, changes were minimal. The results suggest that 5 weeks of effort and duration matched exercise protocols using cycle ergometer training or leg press may produce similar strength adaptations.

Machines and free weight exercises: a systematic review and meta-analysis comparing changes in muscle size, strength, and power

INTRODUCTION

To compare changes in muscle size, strength, and power between free-weight and machine-based exercises.

EVIDENCE ACQUISITION

The online databases of Pubmed, Scopus, and Web of Science were each searched using the following terms: ""free weights" OR barbells OR dumbbells AND machines" up until September 15, 2020. A three-level random effects meta-analytic model was used to compute effect sizes.

EVIDENCE SYNTHESIS

When strength was tested using a free-weight exercise, individuals training with free-weights gained more strength than those training with machines [ES: 0.655; (95% CI: 0.269, 1.041)]. When strength was tested a machine-based exercise incorporated as part of the machine-based training program, individuals training with machines gained more strength than those training with free-weights [ES: -0.784 (95% CI: -1.223, -0.344)]. When strength was tested using a neutral device, machines and free-weight exercises resulted in similar strength gains [ES: 0.128 (95% CI: -0303, 0.559)]. There were no differences in the change in power [ES: -0.049 (95% CI: -0.557, 0.460)] or muscle hypertrophy [ES: -0.01 (95% CI: -0.525, 0.545)] between exercise modes.

CONCLUSIONS

Individuals looking to increase strength and power should take into account the specificity of exercise, and how their strength and power will be tested and applied. Individuals looking to increase general strength and muscle mass to maintain health may choose whichever activity they prefer and are more likely to adhere to.

Assessment of muscle-strengthening exercise in public health surveillance for adults: A systematic review

There is strong scientific evidence that muscle-strengthening exercise (i.e. use of weight machines, push-ups, sit-ups) is independently associated with a reduced risk of multiple chronic diseases (e.g. diabetes, hypertension, cardiovascular disease). However, prevalence rates for meeting the muscle-strengthening exercise guideline (≥2 times/week) are significantly lower (~20%) than those reported to meet the aerobic physical activity guideline (e.g. walking, jogging, cycling) (~50%). It is therefore important to understand public health surveillance approaches to assess muscle-strengthening exercise. The aim of this review was to describe muscle-strengthening exercise assessment in public health surveillance. Informed by the PRISMA guidelines, an extensive keyword search was undertaken across 7 electronic data bases. We identified 86,672 possible articles and following screening (n = 1140 in full-text) against specific inclusion criteria (adults aged ≥18 years, English, studies containing <1000 participants), extracted data from 156 manuscripts. Fifty-eight different survey systems were identified across 17 countries. Muscle-strengthening exercise frequency (85.3%), duration (23.7%) and intensity (1.3%) were recorded. Muscle-strengthening exercise questions varied significantly, with some (11.5%) requiring a singular 'yes' vs 'no' response, while others (7.7%) sought specific details (e.g. muscle groups targeted). Assessments of duration and intensity were inconsistent. Very few studies measured the validity (0.6%) and reliability (1.3%) of muscle-strengthening exercise questions. Discrepancy exists within the current assessment systems/surveys used to assess muscle-strengthening exercise in public health surveillance. This is likely to impede efforts to identify at risk groups and trends within physical activity surveillance, and to accurately assess associations between muscle-strengthening exercise and health-related outcomes.

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

BACKGROUND

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Does resistance training promote enough muscular strength increases to move weak older women to better strength categories?

We compared the magnitude of muscular strength changes among older women occupants of different strength tertiles in response to progressive resistance-training (RT). Additionally, we examined the possibility of older women initially characterized as weak (occupants of the lower tertile of strength status) can achieve a higher muscular strength level to be inserted into a better category (middle or upper tertiles). The present investigation was attended by 113 physically independent older women (>60 years old). Muscular strength was assessed by one-repetition maximum (1RM) tests on chest press, preacher curl, leg extension exercises, and by the isokinetic (ISOK) peak torque of knee extension and flexion at 60 and 180°/s angular velocities. The RT lasted 12 weeks (3 x/week) and consisted of eight exercises for the whole body. The participants were divided into tertiles (LOWER, MIDDLE, and UPPER) according to the performance at baseline for each strength measure. After RT, the LOWER tertile showed more significant magnitude gains than the UPPER tertile to the 1RM in leg extension and preacher curl and isokinetic measurements (6.9-36.3%). A considerable number of older women increased muscular strength enough to move from LOWER to MIDDLE or UPPER tertiles. From our results, it can be inferred that older women occupants of the lower strength tertile show more significant muscular strength gains when compared to their stronger counterparts. Moreover, 12 weeks of RT seem to be sufficient to transfer older women previously characterized as "weak" to a better category.

Associação da autopercepção da qualidade de vida e saúde, prática de atividade física e desempenho funcional entre idosos no interior do Brasil

Resumo Objetivo analisar a autopercepção de saúde e da qualidade de vida associados aos fatores contextuais em idosos não institucionalizados em município rural no interior do Brasil. Método Estudo transversal de base populacional. Foram incluídos indivíduos com 60 anos ou mais, não institucionalizados, residentes em município com características rurais. Foram utilizadas variáveis sociodemográficas, autopercepção da saúde e da qualidade de vida, nível de atividade física e desempenho funcional. Os dados foram coletados em domicílio com aplicação de entrevista e dos instrumentos: WHOQOL BREF, Questionário Internacional de Atividade Física (IPAQ) e teste Timed Up and Go (TUG). Para a análise de comparação e associação foram aplicados os testes qui-quadrado ou exato de Fisher e Razão de Prevalência (RP) e intervalos de confiança (IC). Resultados Participaram do estudo 142 idosos, sendo 58,5% do sexo feminino, com média de idade de 72,4 (±8,0) anos. A autopercepção da saúde foi associada à prática de atividade física (RP=1,13, IC=1,01-1,27) e ao desempenho funcional (RP=1,24, IC=1,03-1,48). A percepção da saúde (RP=1,66, IC=1,57-1,76) e qualidade de vida (RP=1,70, IC=1,60-1,79) boa/muito boa foi associada de forma positiva à prática de atividade física e independência funcional. Conclusão A prática de atividade física e a manutenção da independência funcional contribuem de forma significativa para uma percepção positiva da saúde e qualidade de vida. Porém, idosos insuficientemente ativos e independentes também podem ter boa percepção da saúde. Recomendam-se intervenções nas políticas públicas que considerem características intrínsecas de cada população visando manter ou melhorar a percepção de saúde e qualidade de vida dos idosos.

Does Aerobic and Resistance Exercise Influence Episodic Memory through Unique Mechanisms?

Aerobic and resistance exercise (acute and chronic) independently and collectively induce beneficial responses in the brain that may influence memory function, including an increase in cerebral blood flow, neurogenesis, neuroelectrical alterations, and protein production. However, whether aerobic and resistance exercise improve memory via similar or distinct mechanisms has yet to be fully explained. Here, we review the unique influence of aerobic and resistance exercise on neural modulation, proteins, receptors, and ultimately, episodic memory. Resistance training may optimize neural communication, information processing and memory encoding by affecting the allocation of attentional resources. Moreover, resistance exercise can reduce inflammatory markers associated with neural communication while increasing peripheral and central BDNF (brain-derived neurotrophic factor) production. Aerobic training increases hippocampal levels of BDNF and TrkB (Tropomyosin receptor kinase B), protein kinases and glutamatergic proteins. Likewise, both aerobic and anaerobic exercise can increase CREB (cAMP response element-binding protein) phosphorylation. Thus, we suggest that aerobic and resistance exercise may influence episodic memory via similar and, potentially, distinct mechanisms.

Resistance Training Safety during and after the SARS-Cov-2 Outbreak: Practical Recommendations

In December of 2019, there was an outbreak of a severe acute respiratory syndrome caused by the coronavirus 2 (SARS-CoV-2 or COVID-19) in China. The virus rapidly spread into the whole world causing an unprecedented pandemic and forcing governments to impose a global quarantine, entering an extreme unknown situation. The organizational consequences of quarantine/isolation are absence of organized training and competition, lack of communication among athletes and coaches, inability to move freely, lack of adequate sunlight exposure, and inappropriate training conditions. The reduction of mobility imposed to contain the advance of the SARS-Cov-2 pandemic can negatively affect the physical condition and health of individuals leading to muscle atrophy, progressive loss of muscle strength, and reductions in neuromuscular and mechanical capacities. Resistance training (RT) might be an effective tool to counteract these adverse consequences. RT is considered an essential part of an exercise program due to its numerous health and athletic benefits. However, in the face of the SARS-Cov-2 outbreak, many people might be concerned with safety issues regarding its practice, especially in indoor exercise facilities, such as gyms and fitness centers. These concerns might be associated with RT impact in the immune system, respiratory changes, and contamination due to equipment sharing and agglomeration. In this current opinion article, we provide insights to address these issues to facilitate the return of RT practices under the new logistical and health challenges. We understand that RT can be adapted to allow its performance with measures adopted to control coronavirus outbreak such that the benefits would largely overcome the potential risks. The article provides some practical information to help on its implementation.

The Inverse Association of Muscular Strength with Carotid Intima-media and Extra-media Thickness in Women

The purpose of this study was to determine the relationship between strength and atherosclerotic cardiovascular disease (CVD) risk in young women. Carotid intima-media thickness (IMT) and extra-media thickness (EMT) were used as measures of subclinical atherosclerosis and CVD risk. Muscular strength, IMT, and EMT were measured in 70 young women (mean age=21±4 years). Strength was determined using a handgrip dynamometer and expressed relative to body mass. IMT and EMT were measured using ultrasonography of the left common carotid artery. Objectively measured moderate-vigorous physical activity (MVPA) was assessed with accelerometry. Higher relative handgrip strength was associated with lower IMT (r=-0.23; p<0.05) and lower EMT (r=-0.27; p<0.05). Associations between relative handgrip strength and IMT (r=-0.24) as well as EMT (r=-0.25) remained significant after adjusting for potential confounders including traditional CVD risk factors and MVPA (p<0.05). These results show that there is an inverse association between handgrip strength with carotid IMT and EMT in young women. Muscular strength may reduce CVD risk in young women via favorable effects on subclinical carotid atherosclerosis independent of physical activity.

Importance of Frequency and Intensity of Strength Training for Reduced Musculoskeletal Pain in the Back, Neck-Shoulder, and Arm-Hand Among Physical Therapists

BACKGROUND

Musculoskeletal pain (MP) is common among health care professionals, including physical therapists (PTs). The physically demanding nature of their work might contribute to increase MP rates. Strength training has a positive effect on musculoskeletal health and MP. However, no studies have evaluated the association of strength training during leisure time on MP among PTs. This study aims to analyze the association between frequency and intensity of strength training during leisure time and MP in the back, neck-shoulder, and arm-hand among PTs.

METHODS

Data on MP and intensity and frequency of strength training were obtained using a questionnaire responded by 1006 PTs. The odds for having lower level of MP as a function of intensity or frequency of the strength training were estimated using binary logistic regression.

RESULTS

High-intensity strength training showed strong associations with lower intensity of MP in neck-shoulder (odds ratio = 5.08; 95% confidence interval, 1.36-18.92), arm-hand (odds ratio = 5.22; 95% confidence interval, 1.11-24.51), and back (odds ratio = 5.22; 95% confidence interval, 1.41-19.28). However, frequency and lower intensities were not significantly associated with MP in any body part.

CONCLUSIONS

High-intensity strength training is strongly associated with lower levels of MP in arm-hand, neck-shoulder, and back, whereas no association was found with frequency or lower intensities.

Influence of Handgrip Stabilization During Isokinetic Knee Strength Assessment in Older Women

The present study aimed to evaluate the influence of holding the chair handles during the assessment of older women's knee flexion and extension isokinetic and isometric strength. Of 57 older women (≥60 years) selected from a convenience sample for this research, 23 were randomly chosen to perform the tests twice for reliability analyses. Each participant performed maximal isokinetic knee extension and flexion at 60°/s and 180°/s angular velocities and isometric tests under two conditions: (a) holding the lateral handle of the chair (HOLD) and (b) supporting the hands on the shoulders with the arms crossed (i.e., not holding the handle [NHOLD]). Participants performed significantly better in the HOLD compared with the NHOLD condition. Slightly lower intraclass correlation coefficients (ICC = 0.870-0.956) were noted for the HOLD than for the NHOLD condition (ICC = 0.900-0.981) so that the HOLD performance on Days 1 and 2 was different on some measures. Owing to the higher reliability coefficients in the NHOLD condition, results suggest that, when assessing knee strength in older women, the evaluee should place their hands over their shoulders with arms crossed in front of the chest (NHOLD) to maximize assessment reliability (reproducibility of performance).

Physical Activity, Muscle-Strengthening Activities, and Systemic Inflammation Among Retinopathy Patients

OBJECTIVE

We evaluated the specific association between muscle-strengthening activity (MSA) and accelerometer-assessed physical activity on systemic inflammation among retinopathy patients in the United States.

METHODS

Data from the 2005-2006 National Health and Nutrition Examination Survey (NHANES) were used to identify 157 retinopathy patients between 40 and 85 years of age with complete data on select study variables. MSA was assessed via self-report. Participation in moderate-to-vigorous physical activity (MVPA) was determined from objective accelerometer data. Systemic inflammation was assessed using C-reactive protein (CRP), which was quantified using latex-enhanced nephelometry. Nonproliferative retinopathy was determined using Early Treatment Diabetic Retinopathy Study grading criteria, as well as objective retinal imaging assessments using the Canon Non-Mydriatic Retinal Camera CR6-45NM. Individuals were excluded if they had been diagnosed with coronary artery disease, congestive heart failure, heart attack, or stroke.

RESULTS

MVPA (β = -0.004, 95% CI -0.007 to -0.001, P = 0.006) but not MSA (β = -0.0001, 95% CI -0.002 to 0.001, P = 0.86) was associated with lower CRP levels. Additionally, for a more substantive 30 minutes/day increase in MVPA, there was a corresponding 0.12 mg/dL decrease in CRP.

CONCLUSION

In this nationally representative sample of adults, only individuals who engaged in higher levels of MVPA had lower CRP levels, which is indicative of reduced systemic inflammation. MSA was not associated with systemic inflammation among this cohort. Our findings suggest that MVPA is inversely associated with systemic inflammation among retinopathy patients, which is noteworthy because increased systemic inflammation may facilitate retinopathic severity.

High 1RM Tests Reproducibility and Validity are not Dependent on Training Experience, Muscle Group Tested or Strength Level in Older Women

Background: The maximal one-repetition test (1-RM) is widely used in scientific research; however, there are conflicting results regarding its reproducibility in elderly populations. The present study aimed to analyze the reproducibility of the test both before and after a 12-week training period by using the bench press and leg press 45° 1-RM tests in the elderly, taking into consideration the training experience and strength level of the women. Methods: Elderly women (n = 376; age, 68.5 ± 14.1 years; height, 162.7 ± 5.5 cm; body mass, 71.2 ± 16.0 kg) who underwent ≥3 months of resistance training performed an initial week of familiarization and a second week of testing and retest, with a 48–72 h interval. Results: The results showed that Kappa indices ranged from 0.93 to 0.95, and the intraclass correlation coefficients were 0.99 for both the lower and upper limbs. In addition, minimal detectable changes were found that ranged between 1 and 3%, which means that changes lower than 1 kg could be detected. Conclusion: The present study confirms that the 1-RM test has high reliability and reproducibility in the elderly, for both upper and lower limbs.

Acute effects of different resistance training loads on cardiac autonomic modulation in hypertensive postmenopausal women

BACKGROUND

Individuals with arterial hypertension often have an autonomic nervous system (ANS) imbalance with predominance of sympathetic ANS. This predominance can lead to injury of several organs affecting its functioning. There is evidence that performing high intensity resistance training (RT) with heavier loads and a lower number of repetitions results in lower cardiovascular stress when compared with lighter loads and a higher number of repetitions. However, the effects of different protocols of RT in autonomic modulation are not known. Therefore, the aim of the study was to analyze and compare the effects of different protocols of high intensity of effort RT on autonomic cardiac modulation of hypertensive women.

METHODS

A randomized crossover design clinical trial was conducted with 15 postmenopausal hypertensive women who underwent a control session and two high intensity RT protocols involving 6 and 15 repetition maximum (RM). Heart rate variability (HRV), systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR) and double product (DP) were collected pre, immediately post, 1 h post, and 24 h post each protocol. Repeated-measures ANOVA were used.

RESULTS

SBP was higher for 6RM than control immediately after session (p < 0.05). There were no differences for DBP among protocols (p ≥ 0.05). HR was higher for 15RM than 6RM and control immediately after and 1 h after session (p ≤ 0.05). DP values for 15RM were significantly higher than 6RM and control immediately after the session and remained higher than control 1 h after session (p ≤ 0.05). The indices that compose HRV (rMSSD) were lower after 15RM than 6RM and control (p ≥ 0.05). The parameters of parasympathetic activity (HF) were decreased and sympathetic (LF) activity was increased for 15RM when compared to the 6RM and control session immediately after the exercise session (p ≤ 0.05).

CONCLUSION

Performing high intensity RT with lower loads and a higher number of repetitions seems to promote acute increases in sympathetic ANS activity, which may be related to cardiovascular stress. On the other hand, heavier load and lower repetition RT did not significantly impact upon autonomic modulation when compared to a control session.

The Association between Lower Extremity Muscular Strength and Cognitive Function in a National Sample of Older Adults

Background

We evaluated the association between lower extremity muscular strength and cognition among older adults in the United States.

Methods

Data from the 1999–2002 National Health and Nutrition Examination Survey was used to identify 1508 older adults, between 60–85 years. Muscle strengthening activities were assessed via self-report. Participation in physical activity was determined from self-report data. The DSST was used to assess participant executive cognitive functioning tasks of pairing and free recall. A Kin-Com MP isokinetic dynamometer (Chatanooga Group Inc.) was used to assess lower extremity strength, expressed as absolute strength (N), relative strength (N/body weight in kg), and high (<245.75 N) vs. low (≤245.75 N) absolute strength based on the median levels of strength.

Results

Lower extremity strength (β = 0.01; 95% CI: 0.0008–0.03; p = 0.039) was associated with higher cognitive performance, independent of age, muscle strengthening activities, physical activity and other covariates. In an adjusted multivariate logistic regression model, those with high (vs. low) strength had a 34% reduced odds of having low cognitive function (OR = 0.66; 95% CI: 0.46–0.93; p = 0.02).

Conclusion

In this nationally representative sample of older adults, there was a positive association between elevated lower extremity muscular strength and cognitive functioning.

The affective and behavioral responses to repeated "strength snacks"

Background A training program consisting of only one-repetition maximum (1RM) training results in similar strength adaptations as traditional resistance exercise. However, little is known regarding the affective or behavioral responses to this type of training. Aim To examine the affective and behavioral response to either a traditional resistance exercise program or a biweekly 1RM-training program. Methods Participants were trained for 8 weeks (2× per week). The HYPER group completed four sets of 8-12 repetitions; the 1RM group (TEST) worked up to a single maximal repetition. Results The TEST group felt more revitalized and had an increase in positive engagement during their first visit, whereas the HYPER group showed an increase in feelings of physical exhaustion during their first and last visits. There were no pre to post differences for the change in behavior or self-efficacy between groups. Conclusion 1RM training appears to elicit a more favorable affective response, compared with HYPER training, which may ultimately improve adherence to resistance-type exercise.

Adequate Muscular Strength May Help to Reduce Risk of Residual-Specific Mortality: Findings From the National Health and Nutrition Examination Survey

Objective: Muscular strength has been shown to inversely associate with mortality. The purpose of this study was to examine the association between muscular strength and residual-specific mortality among a national sample of US adults, which has yet to be investigated. Here, residual-specific mortality is identified as deaths not inclusive of the 9 leading causes of death as identified by the International Classification of Diseases, 10th revision. Methods: Data from the 1999–2002 National Health and Nutrition Examination Survey were used (N = 2171 adults, aged 50–85 y). Participants were followed through 2011, including a median follow-up of 125 months. Lower extremity muscular strength was assessed using maximal isokinetic contractions. Results: After adjusting for all covariates (age, gender, race/ethnicity, body mass index, C-reactive protein, mean arterial pressure, self-report of meeting aerobic-based physical activity guidelines, and physician diagnoses of diabetes), the Cox proportional hazard model demonstrated that for every 25 N increase in lower extremity muscular strength, individuals had a 14% reduced risk of residual-specific death (hazard ratio = 0.86; 95% confidence interval, 0.78–0.96; P = .008). Conclusion: Lower body muscular strength is inversely and independently associated with residual-specific mortality risk, underscoring the importance of adequate muscular strength to prolong survival.

Does Strength-Promoting Exercise Confer Unique Health Benefits? A Pooled Analysis of Data on 11 Population Cohorts With All-Cause, Cancer, and Cardiovascular Mortality Endpoints

Public health guidance includes recommendations to engage in strength-promoting exercise (SPE), but there is little evidence on its links with mortality. Using data from the Health Survey for England and the Scottish Health Survey from 1994-2008, we examined the associations between SPE (gym-based and own-body-weight strength activities) and all-cause, cancer, and cardiovascular disease mortality. Multivariable-adjusted Cox regression was used to examine the associations between SPE (any, low-/high-volume, and adherence to the SPE guideline (≥2 sessions/week)) and mortality. The core sample comprised 80,306 adults aged ≥30 years, corresponding to 5,763 any-cause deaths (736,463 person-years). Following exclusions for prevalent disease/events occurring in the first 24 months, participation in any SPE was favorably associated with all-cause (hazard ratio (HR) = 0.77, 95% confidence interval (CI): 0.69, 0.87) and cancer (HR = 0.69, 95% CI: 0.56, 0.86) mortality. Adhering only to the SPE guideline was associated with all-cause (HR = 0.79, 95% CI: 0.66, 0.94) and cancer (HR = 0.66, 95% CI: 0.48, 0.92) mortality; adhering only to the aerobic activity guideline (equivalent to 150 minutes/week of moderate-intensity activity) was associated with all-cause (HR = 0.84, 95% CI: 0.78, 0.90) and cardiovascular disease (HR = 0.78, 95% CI: 0.68, 0.90) mortality. Adherence to both guidelines was associated with all-cause (HR = 0.71, 95% CI: 0.57, 0.87) and cancer (HR = 0.70, 95% CI: 0.50, 0.98) mortality. Our results support promoting adherence to the strength exercise guidelines over and above the generic physical activity targets.

Effects of Sedentary Behavior, Physical Activity, Frequency of Protein Consumption, Lower Extremity Strength and Lean Mass on All-Cause Mortality

Background

No study has evaluated the potential independent and cumulative effects of physical activity, sedentary behavior, daily frequency of protein consumption, lean mass and muscular strength on mortality risk.

Methods

Data from the 1999–2002 NHANES were utilized (N = 1,079 adults 50–85 yr), with follow-up through 2011. Leg lean mass was estimated from DXA scans. Knee extensor strength was assessed using the Kin Com MP dynamometer. Physical activity and sedentary behavior were assessed via questionnaire, with the number of meals/day of ≥30 g of protein/meal assessed via a “multiple pass” 24-hour dietary interview. An index score was created (range = 0–5) indicating the number of these health characteristics each participant had.

Results

Only less sedentary behavior was independently associated with reduced mortality risk (HR_adjustment = 0.46; 0.32–0.66). After adjustments, and compared to those with an index score of 0, those with an index score of 1, 2 and 3+, respectively, had a 34%, 49%, and 57% reduced risk of all-cause mortality.

Conclusion

While considering physical activity, sedentary behavior, daily protein frequency consumption, lean mass and muscular strength, only sedentary behavior was independently associated with mortality risk among older adults.

Muscular performance and body composition changes following multi-joint versus combined multi- and single-joint exercises in aging adults

The aim of the present study was to compare muscular performance and body composition changes following low-volume resistance-training programs consisting of multi-joint (MJ) exercises (cable chest press and seated row) versus a combination of multi- and single-joint (MJ+SJ) exercises (cable chest press, seated row, biceps curl, and triceps extension). Thirty untrained healthy aging adults were randomly assigned to 3 groups: MJ (n = 11), MJ+SJ (n = 11), and control (n = 8). Twelve-repetition maximums (12-RMs) for the cable chest press and seated row, localized muscular endurance for the elbow flexors handgrip strength, and body composition were assessed before and after the 8-week training program. All comparisons were analyzed via a mixed-model analysis with repeated measures (group × time) and the Bonferroni post hoc test (p < 0.05). The MJ and MJ+SJ groups increased performance in the 12-RM cable chest press (MJ = 61.5% ± 24.6% and MJ+SJ = 71.1% ± 25.6%), 12-RM seated row (MJ = 46.4% ± 26.3% and MJ+SJ = 51.5% ± 21.0%), localized muscular endurance (MJ = 24.7% ± 16.7% and MJ+SJ = 37.0% ± 11.4%), and handgrip strength (MJ = 9.3% ± 10.4% and MJ+SJ = 16.6% ± 25.3%) after the intervention. Body composition (i.e., trunk and upper limb fat and lean mass) did not change for any groups. No significant differences were observed between the MJ versus the MJ+SJ protocols after the intervention for any variables. In conclusion, for aging adults, either MJ or MJ+SJ low-volume resistance training resulted in similar increases in 12-RM, localized muscular endurance, and handgrip strength, without changes in body composition after 8 weeks of training.

Cancer-Specific Mortality Relative to Engagement in Muscle-Strengthening Activities and Lower Extremity Strength

BACKGROUND

Skeletal muscle strength and engagement in muscle-strengthening activities are each inversely associated with all-cause mortality; however, less is known on their relationship with cancer-specific mortality.

METHODS

Data from the 1999-2002 National Health and Nutrition Examination Survey were used assessing 2773 individuals aged 50 years or older. Individuals being dichotomized at the 75th percentile for knee extensor strength, and engagement in muscle-strengthening activities was acquired through self-report with ≥2 sessions per week were classified as meeting guidelines.

RESULTS

With respect to cancer-specific mortality, individuals in the upper quartile for muscle strength were at a 50% reduced risk (hazard ratio = 0.50; 95% confidence interval, 0.29-0.85; P = .01) and those meeting muscle-strengthening activities were at a nonsignificant 8% reduced risk (hazard ratio = 0.92; 95% confidence interval, 0.45-1.86, P = .81) of cancer-specific mortality after adjusting for covariates.

CONCLUSIONS

Clinicians should routinely assess lower extremity strength and promote engagement in muscle-strengthening activities aimed at increasing muscle strength.

Muscle activation during resistance training with no external load - effects of training status, movement velocity, dominance, and visual feedback

OBJECTIVES

To explore the acute effects of training status, movement velocity, dominance, and visual feedback on muscle activation and rating of perceived exertion (RPE) during resistance training with no external load (no-load resistance training; NLRT).

METHODS

Thirty-three men (17 untrained and 16 trained), performed elbow flexions in four NLRT sessions: 1) slow velocity with EMG visual feedback, 2) slow velocity without EMG visual feedback, 3) fast velocity with EMG feedback, and 4) fast velocity without EMG feedback. RPE was measured using the Borg Discomfort scale. EMG for the biceps and triceps were recorded for both arms.

RESULTS

EMG feedback had no influence on RPE. The peak and mean EMG values were not different for the biceps (93.8±11.5% and 50±13.1%) and triceps (93.7±23.9% and 49.6±16.2%). The results revealed a difference in the training status, with higher peak EMG for untrained than for trained participants (96.9±20% vs. 90.2±15.6%). However the values for mean EMG were not different between the untrained and trained (50.3±15.7% vs. 49.2±13.7%) participants. There was no difference in the peak (92.8±19% vs. 94.7±20.4%) and mean (49.8±15.0% vs. 49.7±14.5%) EMG values for the dominant and non-dominant sides. Peak EMG values were not different between faster and slower velocities (93.6±19.6% and 93.9±17.8%). However, mean EMG was higher for slower (50.5±14.4%) than for faster (48.5±15.4%) velocities. The peak and mean EMG during contractions with (93.3±17.5% and 49.5±14.1%) and without visual feedback (94.2±19.9% and 50±15.4%) were not significantly different.

CONCLUSION

NLRT produces high levels of muscle activation independent of training, status, dominance, movement velocity, and visual feedback.

Cross-sectional association of exercise, strengthening activities, and cardiorespiratory fitness on generalized anxiety, panic and depressive symptoms

OBJECTIVE

Limited research has evaluated the individual and combined associations of physical activity (PA), cardiorespiratory fitness (CRF) and muscle strengthening activities (MSA) on generalized anxiety, panic and depressive symptoms. We evaluated this topic in a representative sample of young (20-39 years) adults, with considerations by sex.

METHODS

Data from the 1999-2004 National Health and Nutrition Examination Survey (N = 2088) were used. Generalized anxiety, panic and depressive symptoms were assessed via self-report as well as using the Generalized Anxiety Disorder, Panic Disorder, and Depressive Disorders modules of the automated version of the World Health Organization Composite International Diagnostic Interview (CIDI-Auto 2.1). PA and MSA were assessed via validated self-report questionnaires and CRF was determined via a submaximal treadmill-based test. An index variable was created summing the number (range = 0-3) of these parameters for each participant. For example, those meeting PA guidelines, MSA guidelines and having moderate-to-high CRF were classified as having an index score of 3.

RESULTS

MSA was not independently associated with generalized anxiety, panic and depressive symptoms, but those with higher levels of PA and CRF had a reduced odds of these symptoms (ranging from 40 to 46% reduced odds). Compared to those with an index score of 0, those with an index score of 1, 2, and 3, respectively, had a 39%, 54% and 71% reduced odds of having generalized anxiety, panic and depressive symptoms. Results were consistent across both sexes.

CONCLUSION

PA and CRF, but not MSA, were independently associated with generalized anxiety, panic and depressive symptoms. There was evidence of an additive association between PA, CRF, and MSA on these symptoms.

A higher effort-based paradigm in physical activity and exercise for public health: making the case for a greater emphasis on resistance training

It is well known that physical activity and exercise is associated with a lower risk of a range of morbidities and all-cause mortality. Further, it appears that risk reductions are greater when physical activity and/or exercise is performed at a higher intensity of effort. Why this may be the case is perhaps explained by the accumulating evidence linking physical fitness and performance outcomes (e.g. cardiorespiratory fitness, strength, and muscle mass) also to morbidity and mortality risk. Current guidelines about the performance of moderate/vigorous physical activity using aerobic exercise modes focuses upon the accumulation of a minimum volume of physical activity and/or exercise, and have thus far produced disappointing outcomes. As such there has been increased interest in the use of higher effort physical activity and exercise as being potentially more efficacious. Though there is currently debate as to the effectiveness of public health prescription based around higher effort physical activity and exercise, most discussion around this has focused upon modes considered to be traditionally 'aerobic' (e.g. running, cycling, rowing, swimming etc.). A mode customarily performed to a relatively high intensity of effort that we believe has been overlooked is resistance training. Current guidelines do include recommendations to engage in 'muscle strengthening activities' though there has been very little emphasis upon these modes in either research or public health effort. As such the purpose of this debate article is to discuss the emerging higher effort paradigm in physical activity and exercise for public health and to make a case for why there should be a greater emphasis placed upon resistance training as a mode in this paradigm shift.

An Initial Assessment of Secular Trends in Muscular Strength Among Children, Adolescents, and Adults Across the Lifespan: National Sample of Americans

Purpose:

Adequate muscular strength has important implications for morbidity and early mortality prevention. There are no data on the recent trends in muscular strength across lifespan, which was this study’s purpose.

Design:

Cross-sectional.

Setting:

2011 to 2012 and 2013 to 2014 waves of the National Health and Nutrition Examination Survey across the United States.

Participants:

The analyzed sample included 12 295 participants aged 6 to 85 years.

Measures:

Muscular strength was assessed via a handgrip dynamometer.

Analysis:

Adjusted Wald test.

Results:

As expected, men (vs women) had greater grip strength, with grip strength declining as age increased. Central to the focus of this study, there were no changes in absolute or relative grip strength across the waves for any of the evaluated populations (considering age, gender, and race–ethnicity).

Conclusion:

These findings demonstrate that muscular grip strength, across all age, gender, and race–ethnicity populations in the United States, has not changed in the 2 successive 2-year time windows, contained over a 4-year period.

Health Outcomes in Relation to Physical Activity Status, Overweight/Obesity, and History of Overweight/Obesity: A Review of the WATCH Paradigm

Previous research has shown that physical activity may mitigate the association between overweight/obesity and a number of negative health outcomes; however, less is known on how the duration of overweight/obesity alters this association. Therefore, the purpose of this leading article was to synthesize recent studies from our research group examining how physical activity, overweight/obesity classification, and importantly, overweight/obesity duration impact the association with a variety of different health outcomes. Five studies were analyzed, each of which used data from the National Health and Nutrition Examination Survey to analyze six mutually exclusive groups and their respective association with cardiovascular disease risk, all-cause mortality, multi-morbidity, health-related quality of life, and mild depressive symptoms. These studies detailed that physical inactivity, overweight/obesity classification, and overweight/obesity duration were each independently associated with cardiovascular disease risk and multi-morbidity. Additionally, physical activity reduced the risk of all-cause mortality across all weight classifications/durations, and also reduced the association with depressive symptoms and poor health-related quality of life among those overweight/obese for longer durations. These results illustrate that, while physical activity may reduce the association with negative health outcomes, overweight/obesity appears to increase this association independent of physical activity level, with this further exacerbated by the duration of overweight/obesity. Therefore, the emerging studies examining the importance of physical activity among overweight/obese individuals should also consider the duration of overweight/obesity as this will likely alter the associations present.

Epidemiological investigation of muscle-strengthening activities and cognitive function among older adults

Limited research has examined the association of muscle-strengthening activities and executive cognitive function among older adults, which was this study's purpose. Data from the 1999-2002 NHANES were employed (N = 2157; 60-85 years). Muscle-strengthening activities were assessed via self-report, with cognitive function assessed using the digit symbol substitution test. After adjusting for age, age-squared, gender, race-ethnicity, poverty level, body mass index, C-reactive protein, smoking, comorbid illness and physical activity, muscle-strengthening activities were significantly associated with cognitive function (βadjusted = 3.4; 95% CI: 1.7-5.1; P < 0.001). Compared to those not engaging in aerobic exercise and not meeting muscle-strengthening activity guidelines, those doing 1 (βadjusted = 3.7; 95% CI: 1.9-5.4; P < 0.001) and both (βadjusted = 6.6; 95% CI: 4.8-8.3; P < 0.001) of these behaviors had a significantly higher executive cognitive function score. In conclusion, muscle-strengthening activities are associated with executive cognitive function among older U.S. adults, underscoring the importance of promoting both aerobic exercise and muscle-strengthening activities to older adults.

A comparison of low volume 'high-intensity-training' and high volume traditional resistance training methods on muscular performance, body composition, and subjective assessments of training

Most studies of resistance training (RT) examine methods that do not resemble typical training practices of persons participating in RT. Ecologically valid RT programs more representative of such practices are seldom compared. This study compared two such approaches to RT. Thirty participants (males, n = 13; females, n = 17) were randomised to either a group performing low volume 'High Intensity Training' (HIT; n = 16) or high volume 'Body-building' (3ST; n = 14) RT methods 2x/week for 10 weeks. Outcomes included muscular performance, body composition, and participant's subjective assessments. Both HIT and 3ST groups improved muscular performance significantly (as indicated by 95% confidence intervals) with large effect sizes (ES; 0.97 to 1.73 and 0.88 to 1.77 respectively). HIT had significantly greater muscular performance gains for 3 of 9 tested exercises compared with 3ST (p < 0.05) and larger effect sizes for 8 of 9 exercises. Body composition did not significantly change in either group. However, effect sizes for whole body muscle mass changes were slightly more favourable in the HIT group compared with the 3ST group (0.27 and -0.34 respectively) in addition to whole body fat mass (0.03 and 0.43 respectively) and whole body fat percentage (-0.10 and -0.44 respectively). Significant muscular performance gains can be produced using either HIT or 3ST. However, muscular performance gains may be greater when using HIT. Future research should look to identify which components of ecologically valid RT programs are primarily responsible for these differences in outcome.

Healthy Lifestyle Characteristics and Their Joint Association With Cardiovascular Disease Biomarkers in US Adults

OBJECTIVE

To estimate the prevalence of healthy lifestyle characteristics and to examine the association between different combinations of healthy lifestyle characteristics and cardiovascular disease biomarkers.

PATIENTS AND METHODS

The prevalence of healthy lifestyle characteristics was estimated for the US adult population (N=4745) using 2003-2006 National Health and Nutrition Examination Survey data for the following parameters: being sufficiently active (accelerometer), eating a healthy diet (Healthy Eating Index based on 24-hour recalls), being a nonsmoker (serum cotinine level), and having a recommended body fat percentage (dual-energy X-ray absorptiometry). Cardiovascular biomarkers included mean arterial pressure, C-reactive protein, white blood cells (WBCs), total cholesterol, high-density lipoprotein cholesterol (HDL-C), total cholesterol to HDL-C ratio, fasting low-density lipoprotein cholesterol, fasting triglycerides, fasting glucose, fasting insulin, insulin resistance, hemoglobin A1c, and homocysteine. The study was conducted from August 15, 2013, through January 5, 2016.

RESULTS

Only 2.7% (95% CI, 1.9%-3.4%) of all adults had all 4 healthy lifestyle characteristics. Participants with 3 or 4 compared with 0 healthy lifestyle characteristics had more favorable biomarker levels except for mean arterial blood pressure, fasting glucose, and hemoglobin A1c. Having at least 1 or 2 compared with 0 healthy lifestyle characteristics was favorably associated with C-reactive protein, WBCs, HDL-C, total cholesterol, and homocysteine. For HDL-C and total cholesterol, the strongest correlate was body fat percentage. For homocysteine, a healthy diet and not smoking were strong correlates; for WBCs, diet was not a strong correlate.

CONCLUSION

Although multiple healthy lifestyle characteristics are important, specific health characteristics may be more important for particular cardiovascular disease risk factors.