Effects of resistance training interventions on muscular strength in adults with intellectual disability: a systematic review and meta-analysis

Effects of combined training in individual with Intellectual and Developmental Disabilities: a systematic review and meta-analysis of randomized controlled trials

PURPOSE OF THE ARTICLE

This study aims to evaluate the literature, peer-reviewed clinical trials investigating the effects of combined exercise interventions on individuals with Intellectual and Developmental Disabilities.

MATERIALS AND METHODS

Various databases, using various descriptors and Boolean operators were utilized.

RESULTS

Eight studies meet the eligibility criteria. Regarding the anthropometric measures/body composition variable, the meta-analysis revealed that combined physical exercise did not have a significant effect (standard mean difference (SMD) = -0.16; 95% CI, -0.34 to 0.03; Z = 1.68; p = 0.09). For the lipid profile variable, the combined exercise interventions did not show a significant effect (SMD = -0.07; 95% CI, -0.43 to 0.29; Z = 0.38; p = 0.71). Combined exercise training had a significant effect on increasing functional capacity (SMD = 0.28; 95% CI, 0.01 to 0.54; Z = 2.03; p = 0.04), cardiorespiratory function (SMD = 0.80; 95% CI, 0.34 to 1.26; Z = 3.41; p ≤ 0.001), and strength (SMD = 0.77; 95% CI, 0.45 to 1.08; Z = 4.78; p ≤ 0.001).

CONCLUSIONS

Participants from the intervention group that took part in combined exercise training showed a higher probability of improving their functional, cardiorespiratory, and strength capacity compared to the control group.

Making physical activity fun and accessible to adults with intellectual disabilities: A pilot study of a gamification intervention

BACKGROUND

Only about 9% of individuals with intellectual disabilities reach the government's physical activity (PA) recommendations. Combining gamification and technology seems particularly promising in overcoming personal and environmental barriers to PA participation.

METHOD

Eighteen adults with varying levels of intellectual disabilities completed a pilot study to assess the initial effects of a cycling gamification intervention on levels of PA, fitness, psychosocial outcomes, and challenging behaviours. The study comprised three designs: pre-post single group, AB single-case, and qualitative. Social validity, implementation barriers and facilitators were also explored.

RESULTS

Nearly all 18 participants cycled daily. Time and distance cycled daily increase during the intervention while a decrease in stereotyped behaviours was observed. Participants and staff found the intervention enjoyable and socially valid.

CONCLUSIONS

Results of the multiple-design study suggest that gamification interventions may be a suitable, enjoyable, and promising way to contribute to PA participation of adults with intellectual disabilities.

Comparison of Participation in Strength Activity Among People With and Without Disabilities: 2013-2017 Behavioral Risk Factor Surveillance System

BACKGROUND

The current physical activity guidelines recommend engagement in strength activities at least 2 days per week. Currently, there is a lack of literature examining strength activities among people with disabilities. The purpose of this study is to estimate and compare the prevalence of engagement in strength activities and adherence to strength activity guidelines among adults with and without disabilities in the United States.

METHODS

A total of 1,005,644 adults (18-80 y old) with and without disabilities from the 2013 to 2017 Behavioral Risk Factor Surveillance System were included in this secondary data analysis. Descriptive analyses were performed to describe the prevalence of strength activity behaviors of adults with and without disabilities. Logistic and Poisson regression models were performed to evaluate the relative contribution of disability status on strength activity behaviors.

RESULTS

A higher proportion of participants without disabilities (46.42%, 95% CI, 46.18-46.65) reported engaging in strength activities compared with participants with disabilities (30.68%, 95% CI, 30.29-31.08; P < .01). Participants with disabilities were less likely to engage in strength activities (odds ratio = 0.51, 95% CI, 0.50-0.52; adjusted odds ratio = 0.75, 95% CI, 0.73-0.77) and meet strength activity guidelines (odds ratio = 0.56, 95% CI, 0.54-0.57; adjusted odds ratio = 0.75, 95% CI, 0.73-0.77) than participants without disabilities.

CONCLUSION

Experiencing a disability is associated with lower engagement in strength activities; thus, it is important to identify effective and efficient approaches to promoting strength activities among people with disabilities.

Effects of exercise, physical activity, and sports on physical fitness in adults with Down syndrome: A systematic review

This systematic review aimed to analyze the effects of exercise, physical activity, and sports on physical fitness in adults with Down syndrome (DS). A literature search was conducted across four databases EBSCO, Scopus, Web of Science, and PubMed. The PRISMA guidelines were followed. The PEDro scale and the Cochrane risk of bias tool were used to assess the quality and risk of the studies, respectively. The protocol was registered in PROSPERO (code: CRD42023449627). Of the 423 records initially found, 13 were finally included in the systematic review, in which 349 adults with DS participated. 92% of the articles declared at least one significant difference post-intervention. The available evidence indicates that exercise, physical activity, and sports have a positive effect on some variables of physical fitness, especially strength, balance, body composition, cardiorespiratory fitness, flexibility, and functional capacity. Furthermore, it should be considered as an additional treatment or complementary therapy to improve the functionality and quality of life of adults with DS.

Effects of exercise training programs on motor skills of individuals with intellectual disabilities: a systematic review and meta-analysis

PURPOSE

Motor skills are involved in many physical activities and are prerequisites for the performance of sport skills. The purpose of this systematic review was to examine the effects of exercise training programs (ETP) on the motor skills of individuals with intellectual disabilities (IwID).

METHODS

Primary sources were obtained from four databases including PubMed, SCOPUS, CENTRAL, and Web of Science. The search period covered years from inception to October 26th, 2023. Inclusion criteria were as follows: Population: IwID; Intervention: ETP; Comparator: motor skills vs. nontraining control; Outcomes: motor skills outcomes. Standardized mean differences, weighted mean differences, and 95% confidence intervals (CI) were calculated using both random and fixed-effect models for outcomes.

RESULTS

A total of 14 studies involving 586 participants were included in the systematic review. The results of the present meta-analysis showed that ETP improved composite motor skills (1.28 95% CI: [0.86, 1.70], p = 0.001), gross motor skills (0.91, 95% CI: [0.62,1.19], p = 0.001), fine motor skills (0.74, 95% CI: [0.21,1.27], p = 0.01) and fine-gross motor skills (0.64, 95% CI: [0.29, 1.00], p = 0.001).

CONCLUSION

The results meta-analysis demonstrated that ETP improves the motor skills of IwID. Therefore, it is recommended to apply ETP to improve the motor skills of the IwID.

Cut-off points for isometric handgrip and low limb explosive strength in relation to indicators of overweight/obesity in people with intellectual disabilities: analysis by age groups

BACKGROUND

The prevalence of overweight/obesity has been increasing globally and in people with Intellectual Disabilities (IDs), this problem is exacerbated even more, which added to a low physical condition that contributes to the deterioration of functionality and increases the risk of developing chronic diseases in the course of life. Therefore, the aim of this study was to establish cut-off points for levels of isometric handgrip and low limb explosive strength in children, adolescents and adults, which identify overweight/obesity in people with IDs and their respective associations.

METHODS

The sample was made up of 131 individuals with IDs, belonging to four special and community educational centres in the city of Santiago, Chile. Body mass index (BMI) and waist-to-height ratio (WHR) were used as indicators of overweight/obesity. Handgrip strength was used as a measure of isometric strength, and countermovement jump was used as a measure of low limb explosive strength. For the comparison of variables by age group, the analysis of Ancova, Kruskal-Wallis and chi-square tests were used. The total area under the receiver operating characteristic curve of isometric handgrip and low limb explosive strength was identified as an indicator of overweight/obesity according to age groups. A logistic regression model was used to quantify the effect that strength categories below the cut-off point have on the risk of overweight and obesity.

RESULTS

Significant differences were observed between the age groups for body weight, height, BMI and WHR, as well as in the levels of absolute handgrip strength and vertical jump with countermovement (P ≤ 0.05). Children showed the lowest cut-off points for absolute and relative strength. The adolescent group showed the highest cut-off points for relative strength and countermovement jump and adults showed the highest value for absolute strength as indicators of overweight/obesity. Different associations between cut-off points with BMI and WHR were found.

CONCLUSIONS

Adolescents showed the highest cut-off point for relative strength and countermovement jump, and adults showed the highest value for absolute strength, according to overweight/obesity indicators (BMI and WHR). It is suggested to adjust resistance training programmes according to age categories for the prevention of overweight/obesity in people with IDs.

Muscle strength adaptation between high-load resistance training versus low-load blood flow restriction training with different cuff pressure characteristics: a systematic review and meta-analysis

Purpose: In this systematic review and meta-analysis, blood flow restriction (BFR) with low-load resistance training (BFR-RT) was compared with high-load resistance training (HL-RT) on muscle strength in healthy adults. The characteristics of cuff pressure suitable for muscle strength gain were also investigated by analyzing the effects of applying different occlusion pressure prescriptions and cuff inflation patterns on muscle strength gain. Methods: Literature search was conducted using PubMed, Ovid Medline, ProQuest, Cochrane Library, Embase, and Scopus databases to identify literature published until May 2023. Studies reporting the effects of BFR-RT interventions on muscle strength gain were compared with those of HL-RT. The risk of bias in the included trials was assessed using the Cochrane tool, followed by a meta-analysis to calculate the combined effect. Subgroup analysis was performed to explore the beneficial variables. Results: Nineteen articles (42 outcomes), with a total of 458 healthy adults, were included in the meta-analysis. The combined effect showed higher muscle strength gain with HL-RT than with BFR-RT (p = 0.03, SMD = -0.16, 95% CI: -0.30 to -0.01). The results of the subgroup analysis showed that the BFR-RT applied with incremental and individualized pressure achieved muscle strength gain similar to the HL-RT (p = 0.8, SMD = -0.05, 95% CI: -0.44 to 0.34; p = 0.68, SMD = -0.04, 95% CI: -0.23 to 0.15), but muscle strength gain obtained via BFR-RT applied with absolute pressure was lower than that of HL-RT (p < 0.05, SMD = -0.45, 95% CI: -0.71 to -0.19). Furthermore, muscle strength gain obtained by BFR-RT applied with intermittent pressure was similar to that obtained by HL-RT (p = 0.88, SMD = -0.02, 95% CI: -0.27 to 0.23), but muscle strength gain for BFR-RT applied with continuous pressure showed a less prominent increase than that for HL-RT (p < 0.05, SMD = -0.3, 95% CI: -0.48 to -0.11). Conclusion: In general, HL-RT produces superior muscle strength gains than BFR-RT. However, the application of individualized, incremental, and intermittent pressure exercise protocols in BFR-RT elicits comparable muscle strength gains to HL-RT. Our findings indicate that cuff pressure characteristics play a significant role in establishing a BFR-RT intervention program for enhancing muscle strength in healthy adults. Clinical Trial Registration: https://www.crd.york.ac.uk/PROSPERO/#recordDetails; Identifier: PROSPERO (CRD42022364934).

Effects of a 24-week exercise program on anthropometric, body composition, metabolic status, cardiovascular response, and neuromuscular capacity, in individuals with intellectual and developmental disabilities

Introduction: The prevalence of overweight and obesity has increased in the last decades, including in people with Intellectual and Developmental Disabilities (IDD). This is even more concerning when it is globally accepted that a low physical condition contributes to the deterioration of functionality and increases the risk of developing chronic diseases during life, with effective implications for health and well-being. The aim of the present study is to investigate the effects of two physical exercise intervention programs on institutionalized individuals with IDD. Methods: Twenty-one adults with IDD (43.04 ± 11.18 years) were split by convenience into three groups: i) an indoor training group (IG; N = 7; 24-week machine-based gym intervention), ii) an outdoor training group (OG; N = 7; 24-week outdoor intervention with low-content materials), and iii) a control group (CG; N = 7). Assessed outcomes included indicators of health and neuromuscular capacity. The ShapiroWilk (n < 50) and Levene tests were used to verify data normality and homoscedasticity. A Kruskal-Walli test was performed to understand if there were differences between the groups. For comparison purposes and to assess hypothetical differences between groups, the Wilcoxon signed-rank test and the Friedman test were used. The respective effect size was calculated, and the significance level was defined at 0.05. Results/Discussion: There was a difference in fat mass in OG (initial ≠ intermediate; Bonferroni corrected: t = 2.405; p = 0.048; W = 0.08 and initial ≠ final moments; Bonferroni corrected: t = 2.405; p = 0.048; W = 0.08). Indoor intervention programs seem to be more effective than outdoor intervention programs for reducing heart rate rest (t = -2.912; p = 0.011; W = -0.104) when compared with CG. Conclusion: A low-cost outdoor intervention in contact with nature appears to be more effective for fat mass reduction. The results for heart rate variability are not clear and robust. Finally, an indoor intervention using weight-training machines appears to be a good method to promote neuromuscular capacity.

Sports Games and Motor Skills in Children, Adolescents and Youth with Intellectual Disabilities

(1) Background: Sports games are one of the best ways of engaging in physical activity for individuals with intellectual disabilities (ID) and Down syndrome (DS). This systematic review of the current literature aims to identify and sum relevant data on motor skills and clarify whether there are positive effects of sports programs in motor skills games in children, adolescents, and youth with ID and DS. (2) Methods: The systematic review of the papers was carried out following the methodological guidelines and by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) consensus. The following electronic databases were researched: PubMed, MEDLINE, Google Scholar, ScienceDirect, and ERIC from 2001 to 2023. (3) Results: The basketball test battery can be used to improve and monitor basketball training. Basketball players with lower levels of ID achieved better results, especially those with disabilities of the II and III degrees. Futsal has a positive impact on the coordination, and the differences between the test results of the vertical jump with and without an arm swing, that can be seen indirectly as a coordination factor, were statistically significant. (4) Conclusions: Basketball is recommended as an effective and practical rehabilitation program for children, adolescents, and youth with ID and DS. Futsal is an interesting and helpful activity for individuals with ID as well.

Effect of the environmental factor of coexistence on the physical condition of people with mild and moderate intellectual disabilities

BACKGROUND

The main objective of this study was to compare the physical condition of people with intellectual disabilities living in residential homes (RH; restricted residential environment) versus independent homes (IH; family houses while performing paid work). The effect of gender on physical condition was also evaluated separately for each group.

METHOD

Sixty individuals with mild to moderate intellectual disability, 30 living in RH and 30 living in IH, participated in this study. The RH and IH groups were homogeneous in terms of gender distribution (17 males and 13 females) and intellectual disability level. Body composition, postural balance, and static and dynamic force were considered as dependent variables.

RESULTS

The IH group performed better in the postural balance and dynamic force tests compared to the RH group, but no significant differences between the groups were observed for any body composition or static force variable. Women in both groups tended to have better postural balance than men, while men presented higher dynamic force.

CONCLUSIONS

The IH group presented a higher physical fitness compared to RH group. This result emphasises the need to increase the frequency and intensity of the physical activity sessions commonly programed for individuals living in RH.

Effects of Physical Exercise Program in Adults with Intellectual and Developmental Disabilities-A Study Protocol

We developed a physical exercise (PE) program for people with Intellectual and Developmental Disabilities (IDD), aiming to determine the effects on physical fitness, health, cognitive ability, and quality of life (QoL). Using experimental methodology, this intervention study recruited 21 adults (18 to 65 years old), institutionalized and with no other associated pathology, who will be allocated to one of the different groups: (i) gym/indoor intervention group (using weight machines), (ii) outdoor intervention group (using low-cost materials), or (iii) control group (without specific intervention, who continue with their normal daily activities). Both intervention groups will engage in 45 min of training per session, twice a week, for 24 weeks. Assessments will be conducted at baseline (initial assessment), 3 months (mid-term assessment), and 6 months (final assessment). Variables assessed include anthropometrics, body composition, functional capacity, muscle strength, general health, cognitive ability, and QoL. The results of this study will assist in the development of more effective strategies, recommendations, and interventions to ensure better and greater adherence to PE by institutionalized individuals with IDD, namely, recommendations for assessment, prescription, and implementation of PE for this population. Additionally, we intend to make available two PE programs, if they are adapted and promote positive effects.

The Health Effects of 14 Weeks of Physical Activity in a Real-Life Setting for Adults with Intellectual Disabilities

Background

The life expectancy of individuals with intellectual disabilities (ID) is reduced compared to the general population, and one of the main contributors to earlier death is inactivity.

Aim

To investigate how 14 weeks of physical activity (PA) in a real-life setting affects cardiovascular fitness, body composition and bone health of adults with ID.

Methods

Adults with ID were recruited into a PA-group (N = 52) or a control group (CON, N = 14). The PA-group participated in 14 weeks of PA, and body composition, cardiovascular fitness and bone health were assessed before and after the intervention. Outcomes and Results. Cardiovascular fitness and body composition improved from pre to post within the PA-group: Heart rates (HR) during the last 30 seconds of two increments of a treadmill test, were reduced (3.2 km/h: -4.4 bpm, p < 0.05; 4.8 km/h: -7.5 bpm, p < 0.001) and fat mass was reduced (-1.02 kg, p < 0.05). A between-group difference in favour of the PA-group, were observed in whole body bone mineral density (BMD) (0.024 g/cm2, p < 0.05). Conclusions and Implications. Fourteen weeks of PA performed in a real-life setting increased cardiovascular fitness, reduced fat mass and improved BMD in the weight-bearing skeleton in the PA-group. Increased and regular PA seems to be a promising tool to promote physical health in adults with ID.

Eight-week virtual reality training improves lower extremity muscle strength but not balance in adolescents with intellectual disability: A randomized controlled trial

Purpose: This study aims to assess the effects of 8-week virtual reality (VR) training on balance and lower extremity muscle strength in adolescents with intellectual disability (ID).

Methods: Thirty adolescents with intellectual disability were randomly divided into the virtual reality group and control group. The participants in the virtual reality group and the control group received the virtual reality training and the physical education (PE) course, respectively, for 8 weeks. The Berg Balance Scale (BBS), Timed Up and Go (TUG) test and lower extremity muscle strength were measured before and after the training.

Results: The between-group results showed that the participants in the virtual reality group increased the muscle strength of hip flexors (p &lt; 0.001), hip extensors (p = 0.002), hip abductors (p &lt; 0.001), knee flexors (p &lt; 0.001), knee extensors (p = 0.002) and ankle plantar flexors (p = 0.042) significantly after training, compared to the control group. However, no significant improvement was found in the berg balance scale and timed up and go scores between the virtual reality group and control group after training (p &gt; 0.05). The within-group results showed that the strength of all the muscle groups significantly increased after training in the virtual reality group (p &lt; 0.05) compared to the baseline. However, no significant difference was found in the muscle strength in the control group before and after training. The within-group berg balance scale and timed up and go scores showed no significant improvements in both groups.

Conclusion: Virtual reality training intervention might be effective in improving the lower extremity muscle strength, but no significant improvement was found on balance ability in adolescents with intellectual disability.

A Resistance Training Intervention for Adults With Intellectual Disability in the Community: A Pilot Randomized Clinical Trial

Adults with an intellectual disability have significantly lower levels of fitness compared with the general population. This study examined the effects of a 13-week theoretically guided, community-based, multicomponent resistance training intervention, resistance training for empowerment, on muscular strength and independent functional performance in 24 adults with an intellectual disability, aged 18-44 years. Twelve participants were randomly allocated to an experimental group and 12 to an active control group. An analysis of covariance revealed that the experimental group had significantly greater increases (p < .05) on the chest press and leg press one-repetition maximum tests and the 6-min walk test from the baseline to postintervention compared with the control group. The experimental group correctly and independently performed a significantly greater number of steps of resistance training exercise tasks than the control group. Marginal significance and large effect sizes were found for the prone plank test and the stair climb test. The resistance training for empowerment was effective in promoting muscular strength and independent functional performance among adults with an intellectual disability.

Prescription and Effects of Strength Training in Individuals with Intellectual Disability-A Systematic Review

The practice of physical exercise (PE), especially strength training (ST), has health benefits in the healthy population; however, the literature is scarce in the recommendations related to the population with intellectual disability (ID). This study represents the first analysis on the topic and aims to examine the structure and efficacy of ST experimental intervention programs in individuals with ID. This systematic review was carried out between January and April 2021, using the PubMed, Web of Science, Scopus, and SPORTDiscus databases, according to the PRISMA guidelines. From a total of 166 studies, eight were included in the present systematic review. The studies included a total of 280 individuals (18.23 ± 2.86 years old). The main features of the exercise programs are: 12 weeks average duration, three weekly sessions of 45–60 min, six to seven exercises targeting the main muscle groups, two to three sets, 6–12 repetitions, and avoiding free weights for safety reasons. The main results showed increments in strength, balance and fat-free mass and decrements in fat mass and waist circumference. It is a useful guideline for PE technicians to prescribe and adjust correctly in order to not only promote physical fitness, but improve the quality of life of individuals with ID.

A systematic review and meta-analysis of the effects of aerobic exercise interventions on cardiorespiratory fitness in adults with intellectual disability

BACKGROUND

Adults with an intellectual disability (ID) have low cardiorespiratory fitness (CRF). Low CRF has been associated with a high risk of cardiovascular disease and all-cause mortality. Participation in regular exercise can help adults with ID increase their CRF.

OBJECTIVE

To perform a systematic review and meta-analysis of published, peer-reviewed clinical trials that evaluated the effects of aerobic exercise (AE) interventions on CRF in adults with ID, ages 18-65 years.

METHODS

English-language articles were searched up to June 2021 from 11 electronic databases. Data were extracted using an author-developed form. Two independent authors assessed the risk of bias using the Tool for the Assessment of Study Quality and reporting in Exercise (TESTEX). Meta-analysis was performed using the RevMan 5.3.

RESULTS

Of the 1870 article titles and abstracts screened, 16 articles were included. The average TESTEX score (out of 15) was 8.1 (SD = 3.5, range 2-14). The pooled effect was statistically significant (SMD = 0.41, 95% CI: 0.19 to 0.63, z = 3.59; p = .000) with moderate heterogeneity (I² = 35%, p = .000). Both types of intervention produced statistically significant CRF gains, with interventions that combined AE with resistance, balance, and/or flexibility exercises being slightly more effective (SMD = 0.40, 95% CI: 0.11 to 0.70, p = .007) than non-combined interventions (SMD = 0.42, 95% CI: 0.05 to 0.79, p = .02). Heterogeneity was moderate but non-significant for both types of intervention.

CONCLUSIONS

The review supports the use of AE interventions in promoting CRF in adults with ID. The interpretation is limited by the quality of evidence and by poorly described and/or executed familiarization and measurement protocols.