Physical activity in children is associated with several cognitive benefits. Since children and adolescents spend an increasing amount of time engaged in sedentary behavior both at school and in their free time, movement breaks during class hours, in which students are physically active, may be beneficial for effective learning. The aim of this systematic research is to provide an overview of prospective studies investigating the influence of classroom-based physical activity (CB-PA) interventions on attention and on-task behavior in school-aged children and adolescents aged between 4 and 18 years. A systematic search of electronic databases (PubMed, Science Direct, PsycINFO, Ovid), according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, was performed from July 2020 to March 2021. Study characteristics data were analyzed and a methodological quality assessment, using a modified Downs and Black checklist, of both randomized and non-randomized studies was conducted. Overall, the available evidence points to a beneficial effect of exercise on attention and on-task behavior in a classroom setting. However, methodological differences concerning participants and duration and type of physical activity should be considered when comparing the results. Further studies with more comparable methodology are needed to provide a better understanding of the effect of CB-PA on attention and on-task behavior.
Neglecting the use of the affected limb in stroke patients can result in learned non-use. Modified constraint-induced movement therapy (mCIMT) is a form of rehabilitation therapy that limits the less paretic side, and through repeated and concentrated training improve the upper limb function of the paretic side. The aim of this paper is to develop a critical systematic review on the research evidence evaluating the effectiveness of applying mCIMT in the recovery of upper limb function in stroke patients. The outcome of this evaluation support that mCIMT significantly improves the upper limb function of stroke patients. Moreover, group mCIMT modality and TR (trunk restraint)+mCIMT modality provide greater benefits than mCIMT alone.
Although the impact of obesity on exercise performance is multifactorial, excessive fat mass which can impose an unfavorable burden on cardiac function and working muscle, will affect the aerobic exercise capacity. Weight loss strategies, such as bariatric surgery can obviously affect both the body composition and aerobic exercise capacity. Maximal oxygen consumption (V˙O2max) is a widely used important indicator of aerobic exercise capacity of an individual and is closely related to body weight, size and composition. An individual's aerobic exercise capacity may show different results depending on how V˙O2max is expressed. The absolute V˙O2max and V˙O2max relative to body weight are the most commonly used indicators. The V˙O2max relative to fat-free mass, lean body mass or skeletal muscle mass are not influenced by adipose tissue. The last two are more useful to precisely distinguish between individuals differing in muscle adaptation to maximum oxygen uptake. The V˙O2max relative to body height is used for studying growth in children. With the in-depth study of exercise capacity and body composition in obesity, the relative oxygen uptake has been increasingly reinterpreted.
Endurance exercise training promotes a protective phenotype in skeletal muscle known as exercise preconditioning. Exercise preconditioning protects muscle fibers against a variety of threats including inactivity-induced muscle atrophy. The mechanism(s) responsible for exercise preconditioning remain unknown and are explored in these experiments. Specifically, we investigated the impact of endurance exercise training on key components of the renin-angiotensin system (RAS). The RAS was targeted because activation of the classical axis of the RAS pathway via angiotensin II type I receptors (AT1Rs) promotes muscle atrophy whereas activation of the non-classical RAS axis via Mas receptors (MasRs) inhibits the atrophic signaling of the classical RAS pathway. Guided by prior studies, we hypothesized that an exercise-induced decrease in AT1Rs and/or increases in MasRs in skeletal muscle fibers is a potential mechanism responsible for exercise preconditioning. Following endurance exercise training in rats, we examined the abundance of AT1Rs and MasRs in both locomotor and respiratory muscles. Our results indicate that endurance exercise training does not alter the protein abundance of AT1Rs or MasRs in muscle fibers from the diaphragm, plantaris, and soleus muscles compared to sedentary controls (p > 0.05). Furthermore, fluorescent angiotensin II (AngII) binding analyses confirm our results that exercise preconditioning does not alter the protein abundance of AT1Rs in the diaphragm, plantaris, and soleus (p > 0.05). This study confirms that exercise-induced changes in RAS receptors are not a key mechanism that contributes to the beneficial effects of exercise preconditioning in skeletal muscle fibers.
We recently observed a high prevalence of low pelvic bone mineral density (BMD) in female professional ballet performers. Because this population is susceptible to musculoskeletal overuse injuries, we aimed to determine which regions of the pelvis may be at greatest risk compared to general population females (GENPOP) as well as professional female soccer players (SOCCER, a comparison to other elite athletes regularly subjected to high degrees of loading). Three groups of age-matched females [(GENPOP; n = 38, 27±1yrs), (BALLET; single company, n = 36, 26±3yrs), (SOCCER; single NWSL® club, n = 34, 25±1yrs)] consented to have their BMD and body composition assessed (DEXA, GE®). In addition to soft tissue and total and regional BMD analyses, a segmental analysis of the pelvis was performed to determine site-specific BMD for the iliac fossa, iliac fossa/iliac crest/ilium combined, pubic bone, ischium, and sacrum. A mixed-model ANOVA followed by a Tukey's post-hoc test was used to compare the groups (Type-I error; α = 0.05). The BALLET group had lower pelvic BMD for all measures (Avg.%Diff. = 15%-27%, p<0.001) compared to the SOCCER group and for the ischium (Avg.%Diff.= 8%; p=0.007) and sacrum (Avg.%Diff. = 7%; p = 0.028) compared to the GENPOP group. The BALLET group had lower lean mass for all measures compared to the other groups (Avg.%Diff. = 12%-18%; p < 0.01). Professional ballet performers exhibit reduced pelvic region soft tissue and site-specific BMD not previously detected using standard DEXA analyses. These findings highlight which pelvic regions may benefit from preventative strength training and/or nutritional interventions.
The effects of body mass and sex on lower limb biomechanics during ascent and descent were examined in participants aged 50 to 75 with normal weight (n = 19), overweight (n = 18), and obese (n = 8). Peak joint angles and joint moment of the lower limb were analyzed with the VICON motion analysis system. Results from multivariate analysis of variance showed that during descent, the overweight participants had significantly higher knee extensor moment (0.98 ± 0.30 N∙m/kg-1) than the normal-weight participants (0.70 ± 0.29 N∙m/kg-1). The obese group had significantly higher ankle abductor moment (0.21 ± 0.11 N∙m/kg-1) than the normal weight (0.12 ± 0.08 N∙m/kg-1) and overweight groups (0.09 ± 0.06 N∙m/kg-1). During ascent, the obese participants had significant higher hip flexor moment (0.42 ± 0.20 N∙m/kg-1) than overweight participants (0.22 ± 0.17 N∙m/kg-1). Significant sex differences were found in knee extension angles (4.2 ± 3.4° vs 7.0 ± 3.3°) during descent, plantar flexion angles during ascent (23.7 ± 5.3° vs 15.6 ± 3.7°) and descent (29.9 ± 5.0° vs 22.1 ± 7.9°), and ankle adduction angles (6.8 ± 4.8° vs 2.5 ± 2.5°) during ascent. It is concluded that body mass has significant impact on joint loading of lower limbs during stair walking. Being overweight and obese increased hip joint loading during ascent, and knee and ankle joint loading during descent in older adults. Sex difference in joint kinematics was presented during stair walking regardless of the body mass.
Knowledge of measured energy expenditure (EE) during walking and running is important for exercise prescription. Further, research on the EE comparison and EE predicted equation during walking or running among different ethnicities is limited. The purpose of the current study was to compare EE to walk or run 1 mile in Caucasian, African American and Asian adults and to develop a regression equation to predict EE to walk or run 1 mile. Two hundred and twenty-four participants were included (71 Caucasians, 68 African Americans and 85 Asians) with 3 groups (normal weight walking, overweight walking and running). EE was measured via indirect calorimetry. Analysis of variance was used to compare EE across groups. Multiple regression analysis was employed for EE prediction, and the prediction equation was cross-validated. A significant EE difference was found between walking and running among three ethnicities. The prediction equation was: EE = 0.978 Body Weight - 4.571 Gender (male=1; female=2) + 3.524 Ethnicities (Caucasians=1, African Americans=2, Asians=3) + 32.447 (standard error of estimate=12.5 kcal·mile−1). The equation was valid through cross-validation, so it is recommended to apply for calculating EE during walking or running 1 mile among Caucasians, African Americans and Asians.
An active lifestyle has enormous health benefits. However, physical activity has globally decreased since the beginning of the current coronavirus disease 2019 (COVID-19) outbreak because of social distancing measures. Older adults and people with age-related diseases (e.g., diabetes, obesity, cancer, cardiovascular disorders, etc.) are widely affected by COVID-19 and its grave adverse effects because of their baseline poor immune function. Although they are in intense need for the therapeutic benefits of exercise, they may express a low capacity for exercising due to skeletal muscle dysfunction and low motivation. Honey is a natural energy-rich, low glycemic index food with a variety of biological activities. It is reported to correct muscle pathology in diseased conditions. Because skeletal muscle is the key structure involved in the exercise, we explored the literature for the exercise-promoting potential of natural honey. Bee honey improves physical performance at moderate levels of activity, and it reduces the production of inflammatory cytokines and biomarkers of fatigue following strenuous exercise among athletes. Supplementing ischemic heart disease patients with honey combined with floral pollen improved patients’ tolerance for physical loads and corrected metabolic dysfunctions. Therefore, the therapeutic use of honey may have implications for increasing the capacity for exercise in aged and diseased individuals. Soundly designed studies are needed to evaluate such possibilities.