Impact of the association of strength training with neuromuscular electrostimulation on the functionality of individuals with functional decline during senescence: A systematic review and meta-analysis

INTRODUCTION

One of the parameters observed in functional capacity over the years is the decrease in neuromuscular responses, a fact that is attributed to the contemporary lifestyle. Thus, there is a need to carry out interventions that induce the improvement of functional capacity. Some studies have associated electrostimulation (NMES) with Strength Training (ST) to enhance the results in improving neuromuscular function. However, little is known about the effects of this association due to the numerous protocols to be manipulated. Furthermore, adaptive responses to strength training are dependent on volume and intensity manipulation.

OBJECTIVE

To investigate the influence of ST, concomitant with NMES (NMES+) on functional capacity.

METHODS

This is a systematic review with meta-analysis. For the search of the articles, descriptors associated with functional capacity and NMES+ were selected in the Cochrane, PubMed, Embase and VHL meta-searcher databases. Inclusion criteria were articles that presented neuromuscular electrostimulation superimposed on voluntary contraction and ST intensity control; and that did not have a therapeutic purpose. The analysis of titles, abstracts and data extraction were performed by trios of reviewers. To assess the qualities of scientific evidence, the risk of bias was analyzed through the ROB2 tool, meta- analysis and evaluation of the quality of evidence (GRADE).

RESULTS

This meta-analysis selected 3 studies. The main outcomes observed in the studies were agility, balance, cardiorespiratory capacity and strength and power. A significant improvement in effect estimates for cardiorespiratory capacity alone was observed between the two studies.

CONCLUSION

Despite the significant effect of the use of NMES+, in relation to ST in isolation, the quality of the evidence was considered low, probably due to the limited number of scientific evidence found, requiring further studies to identify the real effect of this association.

Different resistance training volumes on strength, functional fitness, and body composition of older people: A systematic review with meta-analysis

Aging causes several changes in the body, reducing strength and muscle mass, which leads to a decline in function. Resistance training (RT) is used to counteract these changes. However, there is still ongoing debate about the optimal volume of RT in the context of aging. We systematically reviewed articles that assessed the impact of different volumes of RT on muscular strength, functional fitness, and body composition of older people. We conducted a systematic search in the PubMed/MEDLINE, Scopus, Embase, Web of Science, Cochrane Library, LILACS, PEDro, and Google Scholar databases, using keywords related to the older population and various RT volumes. We performed meta-analyses for each outcome separately using intervention time in weeks for subgroup analyses. We employed random effects models for all meta-analyses and expressed the results as standardized mean differences (Hedges' g). We included 31 studies, encompassing a total of 1.744 participants. The sample size ranged from 18 to 376, with an average size of 56 participants. Participants' ages ranged from 60 to 83 years. On average, HV-RT (High-Volume Resistance Training) induced significant adaptations in muscle strength of the upper limbs (g = 0.36; 95 % CI = 0.11-0.61) and lower limbs (g = 0.41; 95 % CI = 0.23-0.59), with superiority more pronounced after 12 weeks of training. Regarding functional fitness, there was a tendency favoring HV-RT (g = 0.41; 95 % CI = 0.23-0.59). Thus, HV-RT outperforms LV-RT (Low-Volume Resistance Training) in enhancing muscle strength, particularly in longer interventions with independent older adults.

Maximal Number of Repetitions at Percentages of the One Repetition Maximum: A Meta-Regression and Moderator Analysis of Sex, Age, Training Status, and Exercise

The maximal number of repetitions that can be completed at various percentages of the one repetition maximum (1RM) [REPS ~ %1RM relationship] is foundational knowledge in resistance exercise programming. The current REPS ~ %1RM relationship is based on few studies and has not incorporated uncertainty into estimations or accounted for between-individuals variation. Therefore, we conducted a meta-regression to estimate the mean and between-individuals standard deviation of the number of repetitions that can be completed at various percentages of 1RM. We also explored if the REPS ~ %1RM relationship is moderated by sex, age, training status, and/or exercise. A total of 952 repetitions-to-failure tests, completed by 7289 individuals in 452 groups from 269 studies, were identified. Study groups were predominantly male (66%), healthy (97%), < 59 years of age (92%), and resistance trained (60%). The bench press (42%) and leg press (14%) were the most commonly studied exercises. The REPS ~ %1RM relationship for mean repetitions and standard deviation of repetitions were best described using natural cubic splines and a linear model, respectively, with mean and standard deviation for repetitions decreasing with increasing %1RM. More repetitions were evident in the leg press than bench press across the loading spectrum, thus separate REPS ~ %1RM tables were developed for these two exercises. Analysis of moderators suggested little influences of sex, age, or training status on the REPS ~ %1RM relationship, thus the general main model REPS ~ %1RM table can be applied to all individuals and to all exercises other than the bench press and leg press. More data are needed to develop REPS ~ %1RM tables for other exercises.

Influence of water-based exercise on energy intake, appetite, and appetite-related hormones in adults: A systematic review and meta-analysis

Single bouts of land-based exercise suppress appetite and do not typically alter energy intake in the short-term, whereas it has been suggested that water-based exercise may evoke orexigenic effects. The primary aim was to systematically review the available literature investigating the influence of water-based exercise on energy intake in adults (PROSPERO ID number CRD42022314349). PubMed, Medline, Sport-Discus, Academic Search Complete, CINAHL and Public Health Database were searched for peer-reviewed articles published in English from 1900 to May 2022. Included studies implemented a water-based exercise intervention versus a control or comparator. Risk of bias was assessed using the revised Cochrane 'Risk of bias tool for randomised trials' (RoB 2.0). We identified eight acute (same day) exercise studies which met the inclusion criteria. Meta-analysis was performed using a fixed effects generic inverse variance method on energy intake (8 studies (water versus control), 5 studies (water versus land) and 2 studies (water at two different temperatures)). Appetite and appetite-related hormones are also examined but high heterogeneity did not allow a meta-analysis of these outcome measures. We identified one chronic exercise training study which met the inclusion criteria with findings discussed narratively. Meta-analysis revealed that a single bout of exercise in water increased ad-libitum energy intake compared to a non-exercise control (mean difference [95% CI]: 330 [118, 542] kJ, P = 0.002). No difference in ad libitum energy intake was identified between water and land-based exercise (78 [-176, 334] kJ, P = 0.55). Exercising in cold water (18-20 °C) increased energy intake to a greater extent than neutral water (27-33 °C) temperature (719 [222, 1215] kJ; P < 0.005). The one eligible 12-week study did not assess whether water-based exercise influenced energy intake but did find that cycling and swimming did not alter fasting plasma concentrations of total ghrelin, insulin, leptin or total PYY but contributed to body mass loss 87.3 (5.2) to 85.9 (5.0) kg and 88.9 (4.9) to 86.4 (4.5) kg (P < 0.05) respectively. To conclude, if body mass management is a person's primary focus, they should be mindful of the tendency to eat more in the hours after a water-based exercise session, particularly when the water temperature is cold (18-20 °C).

Benefits of aquatic exercise in adults with and without chronic disease-A systematic review with meta-analysis

Aquatic exercise is being increasingly recommended for healthy individuals as well as people with some special health conditions. A systematic review with meta-analysis was performed to synthesize and analyze data on the effects of water-based training (WT) programs on health status and physical fitness of healthy adults and adults with diseases to develop useful recommendations for health and sports professionals. We searched three databases (PubMed, Web of Science, and Scopus) up to June 2021 for randomized trials that examined WT in adults. A total of 62 studies were included, of which 26 involved only healthy individuals and 36 focused on adults with chronic diseases. In the healthy group, the effects of WT on strength, balance, and cardiorespiratory fitness were beneficial, indicating the usefulness of performing WT for at least 12 weeks (2-3x/week, 46-65 min/session). Among adults with diseases, improvements were observed in patients with fibromyalgia (in balance and cardiorespiratory fitness), bone diseases (pain, balance, flexibility, and strength), coronary artery disease (strength and anthropometry), hypertension (quality of life), stroke (quality of life), diabetes (balance and quality of life), multiple sclerosis (quality of life and balance), and Parkinson's disease (pain, gait, cardiorespiratory fitness, and quality of life). Research is required to determine the effects of WT on patients with heart disease, especially coronary artery disease. In adults with chronic disease, benefits in physical fitness and/or other health-related measures were mainly observed after 8-16 weeks of training. WT is an effective physical activity when the intention is to enhance health and physical fitness in healthy adults and adults with chronic diseases.

Aerobic and combined water-based trainings in older women: effects on strength and cardiorespiratory outcomes

BACKGROUND

The aim of the present study was to investigate the muscular and cardiorespiratory adaptations of two water-based training programs in older women.

METHODS

Volunteers were divided between a water-based aerobic training (WBA; n=13), water-based combined training (WBC; n=11) or an active control group (CG; n=9) and those assigned to WBA and WBC exercised twice a week for 12 weeks. All outcomes of interest were assessed prior and after the intervention. The data were analyzed using Generalized Estimating Equations (GEE), and Bonferroni post-hoc test (α = 0.05). Aerobic training was performed at the percentage of the heart rate corresponding to the anaerobic threshold and resistance training during WBC was performed with sets at maximal effort.

RESULTS

Improvements were observed for the maximal knee extension dynamic strength (1RM) and oxygen uptake (VO2) corresponding to the second ventilatory threshold for both WBA and WBC (1RM: 16 ± 12% vs. 15 ± 16%; VO2: 20 ± 24% vs. 23 ± 13%, respectively), whereas VO2 peak improved in all three groups (WBA: 23 ± 21%; WBC: 18 ± 9%; CG: 7 ± 16%). No increase was found for horizontal chest press 1RM (p > 0.05).

CONCLUSIONS

These results suggest that WBA, WBC and CG are effective to improve cardiorespiratory fitness, however, only water-based training programs (WBA and WBC) appear capable of improving the maximal strength of the lower limbs.

Does aquatic exercise improve commonly reported predisposing risk factors to falls within the elderly? A systematic review

BACKGROUND

According to the World Health Organization, the elderly are at the highest risk of injury or death from a fall. Age-related changes in strength, balance and flexibility are degenerative factors that may increase the risk of falling, and an aquatic training may offer a favourable environment to improve these modifiable risk factors.

METHODS

A systematic review was conducted to assess the potential preventative role of aquatic exercise for reducing the risk of falls in the elderly by improving predisposing risk factors. Electronic databases and reference lists of pertinent articles published between 2005 and 2018 were searched. Randomized controlled trials (RCTs) that directly or indirectly addressed the effect of aquatic exercise for the prevention of falls in healthy participants were included within the synthesis. Studies were included if they were reported between January 2005 and May 2018 within a population aged between 60 and 90 years old that were without exercise-effecting comorbidities. Data related to participant demographics, study design, methodology, interventions and outcomes was extracted by one reviewer. Methodological quality assessment was independently performed by two reviewers using the PEDro (Physiotherapy Evidence Database) scale.

RESULTS

Fourteen trials met the inclusion criteria. Exercise intervention duration and frequency varied from 2 to 24 weeks, from 2 to 3 times per week, from 40 to 90 min per session. Fall rate was not reported in any of the studies analysed. However, aquatic exercise improved key predisposing physical fitness components that are modifiable and internal risk factors for falling.

CONCLUSIONS

There is limited, low-quality evidence to support the use of aquatic exercise for improving physiological components that are risk factors for falling. Although the evidence is limited, and many interventions are not well described, these results should be considered by health and exercise professionals when making evidence-based, clinical decisions regarding training programmes to reduce the risk of falling.