Predicting Deformity Correction of Growth Modulation in Late-onset Tibia Vara.

BACKGROUND: Growth modulation in late-onset tibia vara (LOTV) has been reported to yield variable results. We hypothesized that parameters of deformity severity, skeletal maturity, and body weight could predict the odds of a successful outcome. METHODS: A retrospective review of tension band growth modulation for LOTV (onset ≥8 y) was performed at 7 centers. Tibial/overall limb deformity and hip/knee physeal maturity were assessed on preoperative anteroposterior standing lower-extremity digital radiographs. Tibial deformity change with first-time lateral tibial tension band plating (first LTTBP) was assessed by medial proximal tibia angle (MPTA). Effects of a growth modulation series (GMS) on overall limb alignment were assessed by mechanical tibiofemoral angle (mTFA) and included changes from implant removal, revision, reimplantation, subsequent growth, and femoral procedures during the study period. The successful outcome was defined as radiographic resolution of varus deformity or valgus overcorrection. Patient demographics, characteristics, maturity, deformity, and implant selections were assessed as outcome predictors using multiple logistic regression. RESULTS: Fifty-four patients (76 limbs) had 84 LTTBP procedures and 29 femoral tension band procedures. For each 1-degree decrease in preoperative MPTA or 1-degree increase in preoperative mTFA the odds of their successful correction decreased by 26% in the first LTTBP and 6% by GMS, respectively, controlling for maturity. The change in odds of success for GMS assessed by mTFA was similar when controlling for weight. Closure of a proximal femoral physis decreased the odds of success for postoperative-MPTA by 91% with first LTTBP and for final-mTFA by 90% with GMS, controlling for preoperative deformity. Preoperative weight ≥100 kg decreased the odds of success for final-mTFA with GMS by 82%, controlling for preoperative mTFA. Age, sex, race/ethnicity, type of implant, and knee center peak value adjusted age (a method for bone age) were not predictive of outcome. CONCLUSIONS: Resolution of varus alignment in LOTV using first LTTBP and GMS, as quantified by MPTA and mTFA, respectively, is negatively impacted by deformity magnitude, hip physeal closure, and/or body weight ≥100 kg. The presented table, utilizing these variables, is helpful in the prediction of the outcome of the first LTTBP and GMS. Even if complete correction is not predicted, growth modulation may still be appropriate to reduce deformity in high-risk patients. LEVEL OF EVIDENCE: Level III.

Predicting Success of Deformity Correction With Tension Band Plating in Early-Onset Tibia Vara.

BACKGROUND: Angular deformity correction with tension band plating has not been as successful in early-onset tibia vara (EOTV) as it has been in other conditions. Our hypothesis is that perioperative factors can predict the success of lateral tibial tension band plating (LTTBP) in patients with EOTV. METHODS: A retrospective review was performed at 7 centers evaluating radiographic outcomes of LTTBP in patients with EOTV (onset <7 y of age). Single-event tibial LTTBP outcome was assessed through medial proximal tibial angle (MPTA). The final limb alignment following comprehensive limb growth modulation (CLGM), which could include multiple procedures, was assessed by mechanical axis zone (MAZone), mechanical tibio-femoral angle (mTFA), and mechanical axis deviation (MAD). Preoperative age, weight, deformity severity, medial physeal slope, and Langenskiöld classification +/- modification were investigated as predictors of outcome. Success was defined as the correction or overcorrection to normal age-adjusted alignment. The minimum follow-up was 2 years except when deformity correction, skeletal maturity, or additional surgery occurred. RESULTS: Fifty-two patients with 80 limbs underwent 115 tibial LTTBP procedures at a mean age of 5.3 y, including 78 primary, 21 implant revisions, and 15 reimplantations for recurrence. Tibial LTTBP resulted in a mean change of +8.6 o in MPTA and corrected 53% of tibias. CLGM resulted in MAD correction for 54% of limbs.Univariate analysis showed that success was best predicted by preoperative age, weight, MPTA, and MAD. Multivariate analysis identified that preoperative-MPTA/MAD and preoperative-weight<70 kg were predictive of MPTA and MAD correction, respectively. The probability of success tables are presented for reference. CONCLUSION: Successful correction of MPTA to age-adjusted norms following a single-event LTTBP occurred in 53% of tibias and was best predicted by preoperative-MPTA and preoperative body weight <70 kg. Comprehensive growth modulation corrected limbs in 54%. The probability of correction to age-adjusted MAD is best estimated by preoperative-MAZone 1 or 2 (MAD ≤40 mm). Limbs with preoperative-MAD>80 mm improved, but ultimately all failed to correct completely with CLGM. Osteotomy may need to be considered with these severe deformities. While modified Langenskiöld classification and medial physeal slope have been shown to predict the outcome of osteotomy, they were not predictive for LTTBP. Change in MPTA was common after physeal untethering. LEVEL OF EVIDENCE: Level-III.

Femoral Deformity in Tibia Vara and Its Response to Growth Modulation.

BACKGROUND: While tibia vara is a disorder of the proximal tibial physis, femoral deformity frequently contributes to the overall limb malalignment. Our purpose was to determine how femoral varus deformity in tibia vara responds to growth modulation, with/without lateral tension band plating (LTBP) to the femur. METHODS: One-hundred twenty-seven limbs undergoing LTBP for tibia vara were reviewed. All had tibial LTBP and 35 limbs also had femoral LTBP for varus. Radiographs were measured for correction of the mechanical lateral distal femoral angle (mLDFA) and mechanical axis deviation (MAD). Preoperative-femoral varus was defined with an age-adjusted guide: mLDFA >95 degrees for 2 to below 4 years and mLDFA >90 degrees for 4 to 18 years. The 35 limbs having femoral LTBP were compared with 50 limbs with femoral varus and no femoral LTBP. In addition, 42 limbs that did not have preoperative-femoral varus were followed. Patients with early-onset (below 7 y) tibia vara were compared with those with late-onset (≥8 y). Outcome success was based on published age-adjusted mLDFA and MAD norms. RESULTS: Following femoral LTBP, the mean mLDFA decreased from 98.0 to 87.1 degrees. All femurs had some improvement, with 28/35 femurs (80%) achieving complete correction. One limb, with late follow-up, overcorrected, requiring reverse (medial) femoral tension band plating.For the 50 limbs with femoral varus and only tibial LTBP, 16/22 limbs (73%) with early-onset and 11/28 limbs (39%) with late-onset completely corrected their femoral deformities. If the limb had preoperative-femoral varus, femoral LTBP statistically correlated with successful mLDFA correction and improvement of MAD, only in the late-onset group.Forty-two limbs, without preoperative-femoral varus, had no change in their mean mLDFA of 87 degrees. However, 4 femurs (10%) ended with posttreatment varus. CONCLUSIONS: Femoral LTBP is effective in correcting femoral varus deformity in the tibia vara. For femoral varus associated with late-onset tibia vara, femoral LTBP should be considered. Those that had femoral LTBP had statistically more successful femoral and overall limb varus correction. However, in early-onset tibia vara, with associated femoral varus, observation is warranted because 73% of femurs are corrected without femoral intervention. This study was underpowered to show additional improvement with femoral LTBP in the early-onset group. Even limbs with normal femoral alignment, should be observed closely for the development of femoral varus, during tibial LTBP treatment for tibia vara. LEVEL OF EVIDENCE: Level III.

Status and Trends of Physical Activity Surveillance, Policy, and Research in 164 Countries: Findings From the Global Observatory for Physical Activity-GoPA! 2015 and 2020 Surveys.

BACKGROUND: Physical activity (PA) surveillance, policy, and research efforts need to be periodically appraised to gain insight into national and global capacities for PA promotion. The aim of this paper was to assess the status and trends in PA surveillance, policy, and research in 164 countries. METHODS: We used data from the Global Observatory for Physical Activity (GoPA!) 2015 and 2020 surveys. Comprehensive searches were performed for each country to determine the level of development of their PA surveillance, policy, and research, and the findings were verified by the GoPA! Country Contacts. Trends were analyzed based on the data available for both survey years. RESULTS: The global 5-year progress in all 3 indicators was modest, with most countries either improving or staying at the same level. PA surveillance, policy, and research improved or remained at a high level in 48.1%, 40.6%, and 42.1% of the countries, respectively. PA surveillance, policy, and research scores decreased or remained at a low level in 8.3%, 15.8%, and 28.6% of the countries, respectively. The highest capacity for PA promotion was found in Europe, the lowest in Africa and low- and lower-middle-income countries. Although a large percentage of the world's population benefit from at least some PA policy, surveillance, and research efforts in their countries, 49.6 million people are without PA surveillance, 629.4 million people are without PA policy, and 108.7 million live in countries without any PA research output. A total of 6.3 billion people or 88.2% of the world's population live in countries where PA promotion capacity should be significantly improved. CONCLUSION: Despite PA is essential for health, there are large inequalities between countries and world regions in their capacity to promote PA. Coordinated efforts are needed to reduce the inequalities and improve the global capacity for PA promotion.

Motorized Intramedullary Nail Lengthening in the Older Population.

Limb lengthening has not been widely employed in the elderly population due to concerns that outcomes will be inferior. The purpose of this multicenter, retrospective case-control series was to report the bone healing outcomes and complications of lower limb lengthening in older patients (≥60 years) using magnetic intramedullary lengthening nail (MILN). Our hypothesis was that healing parameters including consolidation days, the consolidation index, maturation days, and the maturation index, as well as the number of adverse events reported in the older population, would be no different to those of the general adult population. We retrospectively reviewed charts and radiographs from patients ≥60 years of age with limb-length discrepancies who underwent femoral or tibial lengthening using a MILN. Parameters were compared among the age categories "≤19 years," "20-39 years," "40-59 years," or "≥60 years" and propensity-matched cohorts for the age groups 20-59 years and ≥60 years. Complications were reported as percentages for each age category. In the study period, 354 MILN were placed in 257 patients. Sixteen nails were placed in patients 60 years of age or older (mean 65 ± 5 years; range 60-72 years). Comparisons of healing parameters showed no difference between those aged 60+ and the younger cohort. Complication percentages were not statistically significant (p = 0.816). Limb lengthening with MILN may therefore be considered a safe and feasible option for a generally healthy elderly population.

Guided Growth Procedures: Broken Tension Band Implants in Patients With Blount Disease.

BACKGROUND: Tension band plate and screw implants (TBI) are frequently used for temporary hemiepiphyseodeses to manage angular deformity in growing children. The reported implant breakage rate, when TBI is used for deformities in patients with Blount disease, is much higher than when used in other diagnoses. Our hypothesis is that perioperative factors can identify risks for TBI breakage. METHODS: A retrospective case-control study was performed of 246 TBI procedures in 113 patients with Blount disease at 8 tertiary pediatric orthopaedic centers from 2008 to 2018. Patient demographics, age at diagnosis, weight, body mass index (BMI), radiographic deformity severity measures, location, and types of implants were studied. The outcome of implant breakage was compared with these perioperative factors using univariate logistic regression with Bonferroni correction for multiplicity to significance tests. RESULTS: There were 30 broken implants (12%), failing at mean 1.6 years following implantation. Most failures involved the metaphyseal screws. Increased BMI was associated with increased implant breakage. Increased varus deformity was directly associated with greater implant breakage and may be a more important factor in failure for those below 7 years compared with those 8 years or above at diagnosis. There was a 50% breakage rate for TBI with solid 3.5 mm screws in Blount disease with onset 8 years or above of age. No demographic or implant factors were found to be significant. CONCLUSIONS: Breakage of TBI was associated with increased BMI and varus deformity in patients with Blount disease. Larger studies are required to determine the relative contribution and limits of each parameter. Solid 3.5 mm screws should be used with caution in TBI for late-onset Blount disease. LEVEL OF EVIDENCE: Level III.

Physical activity and sleep: An updated umbrella review of the 2018 Physical Activity Guidelines Advisory Committee report.

Physical activity (PA) is widely considered to improve sleep, but a comprehensive review of the research on this topic has not been performed. In this umbrella review, conducted initially for the 2018 Physical Activity Guidelines for Americans Advisory Committee and updated to reflect more recent research, we examined whether PA enhances sleep outcomes across the lifespan as well as among individuals with sleep disorders. Systematic reviews and meta-analyses were utilized to assess the evidence. We also examined dose-response considerations and whether the association between PA and sleep was moderated by various factors (e.g., timing, sociodemographic characteristics). We found strong evidence that both acute bouts of PA and regular PA improved sleep outcomes. Moderate evidence indicated that longer bouts of PA (both acute and regular) improved sleep, and that the effects of PA on sleep outcomes were generally preserved across adult age groups and sex. Finally, moderate evidence demonstrated that PA improved sleep in adults with insomnia symptoms or obstructive sleep apnea. Several important areas in need of future research were also identified. Overall, the review supported the claim that PA improves sleep, but highlighted gaps that need to be addressed to facilitate more widespread utilization of PA for improving sleep.

Discovery of Sisunatovir (RV521), an Inhibitor of Respiratory Syncytial Virus Fusion.

RV521 is an orally bioavailable inhibitor of respiratory syncytial virus (RSV) fusion that was identified after a lead optimization process based upon hits that originated from a physical property directed hit profiling exercise at Reviral. This exercise encompassed collaborations with a number of contract organizations with collaborative medicinal chemistry and virology during the optimization phase in addition to those utilized as the compound proceeded through preclinical and clinical evaluation. RV521 exhibited a mean IC50 of 1.2 nM against a panel of RSV A and B laboratory strains and clinical isolates with antiviral efficacy in the Balb/C mouse model of RSV infection. Oral bioavailability in preclinical species ranged from 42 to >100% with evidence of highly efficient penetration into lung tissue. In healthy adult human volunteers experimentally infected with RSV, a potent antiviral effect was observed with a significant reduction in viral load and symptoms compared to placebo.

A systematic review of physical activity and quality of life and well-being.

Maintaining or improving quality of life (QoL) and well-being is a universal goal across the lifespan. Being physically active has been suggested as one way to enhance QoL and well-being. In this systematic review, conducted in part for the 2018 U.S. Health and Human Services Physical Activity Guidelines for Americans Scientific Advisory Committee Report, we examined the relationship between physical activity (PA) and QoL and well-being experienced by the general population across the lifespan and by persons with psychiatric and neurologic conditions. Systematic reviews, meta-analyses, and pooled analyses from 2006 to 2018 were used for the evidence base. Strong evidence (predominantly from randomized controlled trials [RCTs]) demonstrated that, for adults aged 18-65 years and older adults (primarily 65 years and older), PA improves QoL and well-being when compared with minimal or no-treatment controls. Moderate evidence indicated that PA improves QoL and well-being in individuals with schizophrenia and Parkinson's disease, and limited evidence indicated that PA improves QoL and well-being for youth and for adults with major clinical depression or bipolar disorder. Insufficient evidence existed for individuals with dementia because of a small number of studies with mixed results. Future high-quality research designs should include RCTs involving longer interventions testing different modes and intensities of PA in diverse populations of healthy people and individuals with cognitive (e.g., dementia) and mental health conditions (e.g., schizophrenia) to precisely characterize the effects of different forms of PA on aspects of QoL and well-being.

Canadian 24-Hour Movement Guidelines for Adults aged 18-64 years and Adults aged 65 years or older: an integration of physical activity, sedentary behaviour, and sleep.

The Canadian Society for Exercise Physiology assembled a Consensus Panel representing national organizations, content experts, methodologists, stakeholders, and end-users and followed an established guideline development procedure to create the Canadian 24-Hour Movement Guidelines for Adults aged 18-64 years and Adults aged 65 years or older: An Integration of Physical Activity, Sedentary Behaviour, and Sleep. These guidelines underscore the importance of movement behaviours across the whole 24-h day. The development process followed the strategy outlined in the Appraisal of Guidelines for Research and Evaluation (AGREE) II instrument. A large body of evidence was used to inform the guidelines including 2 de novo systematic reviews and 4 overviews of reviews examining the relationships among movement behaviours (physical activity, sedentary behaviour, sleep, and all behaviours together) and several health outcomes. Draft guideline recommendations were discussed at a 4-day in-person Consensus Panel meeting. Feedback from stakeholders was obtained by survey (n = 877) and the draft guidelines were revised accordingly. The final guidelines provide evidence-based recommendations for a healthy day (24-h), comprising a combination of sleep, sedentary behaviours, and light-intensity and moderate-to-vigorous-intensity physical activity. Dissemination and implementation efforts with corresponding evaluation plans are in place to help ensure that guideline awareness and use are optimized. Novelty First ever 24-Hour Movement Guidelines for Adults aged 18-64 years and Adults aged 65 years or older with consideration of a balanced approach to physical activity, sedentary behaviour, and sleep Finalizes the suite of 24-Hour Movement Guidelines for Canadians across the lifespan.

Sedentary behaviour and health in adults: an overview of systematic reviews.

The purpose of this overview of systematic reviews was to determine the relationship between different types and patterns of sedentary behaviour and selected health outcomes in adults and older adults. Five electronic databases were last searched in May, 2019, with a 10-year search limit. Included reviews met the a priori population (community-dwelling adults aged 18 years and older), intervention/exposure/comparator (various types and/or patterns of sedentary behaviour), and outcomes criteria. Eighteen systematic reviews were included in the evidence synthesis. High levels of sedentary behaviour are unfavourably associated with cognitive function, depression, function and disability, physical activity levels, and physical health-related quality of life in adults. Reducing or breaking up sedentary behaviour may benefit body composition and markers of cardiometabolic risk. Total sedentary behaviour and TV viewing were most consistently associated with unfavourable health outcomes, while computer and Internet use may be favourably associated with cognitive function for older adults. The quality of evidence within individual reviews (as assessed by review authors) varied from low to high, while the certainty of evidence was low to very low. These findings have important public health implications, suggesting that adults should avoid high levels of sedentary behaviour and break-up periods of prolonged sitting. (PROSPERO registration nos.: CRD42019123121 and CRD42019127157.) Novelty High levels of sedentary behaviour are unfavourably associated with important health outcomes in adults. Reducing or breaking up sedentary behaviour may benefit body composition and markers of cardiometabolic risk. Computer and Internet use may be favourably associated with cognitive function in older adults.

A Randomized, Placebo-Controlled, Respiratory Syncytial Virus Human Challenge Study of the Antiviral Efficacy, Safety, and Pharmacokinetics of RV521, an Inhibitor of the RSV-F Protein.

Effective treatments for respiratory syncytial virus (RSV) infection are lacking. Here, we report a human proof-of-concept study for RV521, a small-molecule antiviral inhibitor of the RSV-F protein. In this randomized, double-blind, placebo-controlled trial, healthy adults were challenged with RSV-A Memphis-37b. After infection was confirmed (or 5 days after challenge virus inoculation), subjects received RV521 (350 mg or 200 mg) or placebo orally every 12 h for 5 days. The primary endpoint was area under the curve (AUC) for viral load, as assessed by reverse transcriptase quantitative PCR (RT-qPCR) of nasal wash samples. The primary efficacy analysis set included subjects successfully infected with RSV who received ≥1 dose of study drug. A total of 66 subjects were enrolled (n = 22 per group); 53 were included in the primary analysis set (RV521 350 mg: n = 16; 200 mg: n = 18; placebo: n = 19). The mean AUC of RT-qPCR-assessed RSV viral load (log10 PFU equivalents [PFUe]/ml · h) was significantly lower with RV521 350 mg (185.26; standard error [SE], 31.17; P = 0.002) and 200 mg (224.35; SE, 37.60; P = 0.007) versus placebo (501.39; SE, 86.57). Disease severity improved with RV521 350 mg and 200 mg versus placebo (P = 0.002 and P = 0.009, respectively, for AUC total symptom score [score × hours]). Daily nasal mucus weight was significantly reduced (P = 0.010 and P = 0.038 for RV521 350 mg and 200 mg, respectively, versus placebo). All treatment-emergent adverse events were grade 1 or 2. No subjects discontinued due to adverse events. There was no evidence of clinically significant viral resistance, and only three variants were detected. RV521 effectively reduced RSV viral load and disease severity in humans and was well tolerated. (This study has been registered at ClinicalTrials.gov under registration no. NCT03258502.).

Daily Step Counts for Measuring Physical Activity Exposure and Its Relation to Health.

PURPOSE: A systematic primary literature review was conducted to evaluate the relationship of physical activity-as measured by daily step counts-with all-cause mortality, cardiovascular disease mortality, incident cardiovascular disease, and type 2 diabetes mellitus; to evaluate the shape of dose-response relationships; and to interpret findings in the context of development of the Physical Activity Guidelines for Americans, Second Edition. METHODS: A primary literature search encompassing 2011 to March 2018 for existing literature reporting on these relationships was conducted. RESULTS: Eleven pertinent articles were identified. Seven longitudinal studies examined the relationship between daily step counts and mortality, disease incidence, or risk. Two studies examined objectively measured steps per day and all-cause mortality; one was restricted to a relatively small elderly population. One study examined cardiovascular events, defined as cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke. The other four longitudinal studies addressed incident type 2 diabetes. All longitudinal studies reported an inverse relationship between steps per day and outcome risk. In one study, 531 cardiovascular events occurred during more than 45,000 person-years of follow-up. Before intervention, each increment of 2000 steps per day up to 10,000 steps was associated with a 10% lower cardiovascular event rate. Also, for every increase of 2000 steps per day over baseline, there was an 8% yearly reduction in cardiovascular event rate in individuals with impaired glucose tolerance. CONCLUSIONS: Daily step count is a readily accessible means by which to monitor and set physical activity goals. Recent evidence supports previously limited evidence of an inverse dose-response relationship of daily steps with important health outcomes, including all-cause mortality, cardiovascular events, and type 2 diabetes. However, more independent studies will be required before these observations can be translated into public health guidelines.

Association between Bout Duration of Physical Activity and Health: Systematic Review.

PURPOSE: This study aimed to conduct a systematic literature review to determine whether physical activity episodes of <10 min in duration have health-related benefits or, alternatively, if the benefits are only realized when the duration of physical activity episodes is ≥10 min. METHODS: The primary literature search was conducted for the 2018 Physical Activity Guidelines Advisory Committee Report and encompassed literature through June 2017, with an additional literature search conducted to include literature published through March 2018 for inclusion in this systematic review. RESULTS: The literature review identified 29 articles that were pertinent to the research question that used either cross-sectional, prospective cohort, or randomized designs. One prospective cohort study (N = 4840) reported similar associations between moderate to vigorous physical activity (MVPA) and all-cause mortality when examined as total MVPA, MVPA in bouts ≥5 min in duration, or MVPA in bouts ≥10 min in duration. Additional evidence was identified from cross-sectional and prospective studies to support that bouts of physical activity <10 min in duration are associated with a variety of health outcomes. Randomized studies only examined bouts of physical activity ≥10 min in duration. CONCLUSIONS: The current evidence, from cross-sectional and prospective cohort studies, supports that physical activity of any bout duration is associated with improved health outcomes, which includes all-cause mortality. This may suggest the need for a contemporary paradigm shift in public health recommendations for physical activity, which supports total MVPA as an important lifestyle behavior regardless of the bout duration.

Sedentary Behavior and Health: Update from the 2018 Physical Activity Guidelines Advisory Committee.

PURPOSE: To provide an overview of relationships between sedentary behavior and mortality as well as incidence of several noncommunicable diseases and weight status reported in the 2018 Physical Activity Guidelines Advisory Committee Scientific Report (2018 PAGAC Scientific Report), and to update the evidence from recent studies. METHODS: Evidence related to sedentary behavior in the 2018 PAGAC Scientific Report was summarized, and a systematic review was undertaken to identify original studies published between January 2017 and February 2018. RESULTS: The 2018 PAGAC Scientific Report concluded there was strong evidence that high amounts of sedentary behavior increase the risk for all-cause and cardiovascular disease (CVD) mortality and incident CVD and type 2 diabetes. Moderate evidence indicated sedentary behavior is associated with incident endometrial, colon and lung cancer. Limited evidence suggested sedentary behavior is associated with cancer mortality and weight status. There was strong evidence that the hazardous effects of sedentary behavior are more pronounced in physically inactive people. Evidence was insufficient to determine if bout length or breaks in sedentary behavior are associated with health outcomes. The new literature search yielded seven new studies for all-cause mortality, two for CVD mortality, two for cancer mortality, four for type 2 diabetes, one for weight status, and four for cancer; no new studies were identified for CVD incidence. Results of the new studies supported the conclusions in the 2018 PAGAC Scientific Report. CONCLUSIONS: The results of the updated search add further evidence on the association between sedentary behavior and health. Further research is required on how sex, age, race/ethnicity, socioeconomic status, and weight status may modify associations between sedentary behavior and health outcomes.

High-Intensity Interval Training for Cardiometabolic Disease Prevention.

PURPOSE: The 2018 Physical Activity Guidelines Advisory Committee systematically searched existing literature reviews to assess the relationship between high-intensity interval training (HIIT) and reduction in cardiometabolic disease risk. METHODS: Duplicate independent screenings of 260 articles identified from PubMed®, Cochrane Library, and CINAHL databases yielded suitable data from one systematic review and two meta-analyses. Search terms included a combination of "high intensity" "physical activity/exercise" and "interval training" and outcome-specific terms. The quality of the included reviews was assessed using a tailored version of the AMSTARExBP report on quality. Exposure Subcommittee members graded scientific evidence strength based on a five-criteria rubric and assigned one of four grades: strong, moderate, limited, or not assignable. RESULTS: Moderate evidence indicates that HIIT can improve insulin sensitivity, blood pressure, and body composition in adults with group mean ages ranging from ~20 to ~77 yr. These HIIT-induced improvements in cardiometabolic disease risk factors are comparable with those resulting from moderate-intensity continuous training, and they are more likely to occur in adults at higher risk of cardiovascular disease and diabetes than in healthy adults. Moderate evidence also indicates that adults with overweight or obesity classification are more responsive than adults with normal weight to HIIT-related improvements in insulin sensitivity, blood pressure, and body composition. Insufficient evidence was available to determine whether a dose-response relationship exists between the quantity of HIIT performed and several risk factors for cardiovascular disease and diabetes, or whether the effects of HIIT on cardiometabolic disease risk factors are influenced by age, sex, race/ethnicity, or socioeconomic status. CONCLUSIONS: HIIT by adults, especially those with overweight and obesity classification, can improve insulin sensitivity, blood pressure, and body composition, comparable with those resulting from moderate-intensity continuous training.

Physical Activity, Cognition, and Brain Outcomes: A Review of the 2018 Physical Activity Guidelines.

PURPOSE: Physical activity (PA) is known to improve cognitive and brain function, but debate continues regarding the consistency and magnitude of its effects, populations and cognitive domains most affected, and parameters necessary to achieve the greatest improvements (e.g., dose). METHODS: In this umbrella review conducted in part for the 2018 Health and Human Services Physical Activity Guidelines for Americans Advisory Committee, we examined whether PA interventions enhance cognitive and brain outcomes across the life span, as well as in populations experiencing cognitive dysfunction (e.g., schizophrenia). Systematic reviews, meta-analyses, and pooled analyses were used. We further examined whether engaging in greater amounts of PA is associated with a reduced risk of developing cognitive impairment and dementia in late adulthood. RESULTS: Moderate evidence from randomized controlled trials indicates an association between moderate- to vigorous-intensity PA and improvements in cognition, including performance on academic achievement and neuropsychological tests, such as those measuring processing speed, memory, and executive function. Strong evidence demonstrates that acute bouts of moderate- to vigorous-intensity PA have transient benefits for cognition during the postrecovery period after exercise. Strong evidence demonstrates that greater amounts of PA are associated with a reduced risk of developing cognitive impairment, including Alzheimer's disease. The strength of the findings varies across the life span and in individuals with medical conditions influencing cognition. CONCLUSIONS: There is moderate-to-strong support that PA benefits cognitive functioning during early and late periods of the life span and in certain populations characterized by cognitive deficits.

Physical Activity and Health in Children Younger than 6 Years: A Systematic Review.

PURPOSE: Physical activity is known to provide important health benefits in school-age youth. However, until recently, few studies have examined associations between physical activity and health in young children. The purpose of this study was to conduct a systematic review of the relationship between physical activity and selected health outcomes in children younger than 6 yr. METHODS: A systematic search identified randomized controlled trials and prospective cohort studies examining the associations between physical activity and adiposity/weight status, bone health, cardiometabolic health, and cognition in children younger than 6 yr. RESULTS: Twenty-seven studies met inclusion criteria and served as the basis for this systematic review. For weight status/adiposity, 12 of 15 studies found negative associations between physical activity and one or more measures of the outcome. For bone health, 10 articles based on four studies were identified, and nine studies showed stronger bone in more active children. For cardiometabolic health, three studies were identified and findings were limited and inconsistent. For cognition, two systematic reviews were identified and findings were limited. For all four health outcomes, evidence of dose-response relationships and effect modification by demographic factors was very limited. CONCLUSIONS: There is strong evidence indicating that higher amounts of physical activity are associated with better indicators of bone health and with reduced risk for excessive increases in weight and adiposity in children 3 to 6 yr. Evidence was too limited to support conclusions regarding the effects of physical activity on cardiometabolic health and cognition.