Effect of strength training on rate of force development in older women

Exercise training effect on skeletal muscle motor drive in older adults: A systematic review with meta-analysis of randomized controlled trials

The meta-analysis aimed to determine whether exercise training can positively change indices of motor drive, i.e., the input from the central nervous system to the muscle, and how training characteristics, motor drive assessment, assessed muscle, and testing specificity could modulate the changes in motor drive in older adults. A random-effect meta-analysis model using standardized mean differences (Hedges' g) determined treatment effects. Moderators (e.g., training type and intensity) and meta-regressors (e.g., number of sessions) were performed using mixed- and fixed-effect models. A significant Q-test, followed by pairwise post hoc comparisons, determined differences between levels of the categorical moderators. Methodological quality was assessed using the Cochrane risk of bias tool. Ten randomized controlled trials, 290 older adults, met the inclusion criteria. Only strength and power exercise training were retrieved from the search and included in the analysis. Strength (g = 0.60, 95 % CI 0.24 to 0.96) and power training (g = 0.51, 95 % CI 0.02 to 1.00) increased motor drive compared with a control condition. High (g = 0.66; 95 % CI 0.34 to 0.97) and low-high (g = 1.23; 95 % CI 0.19 to 2.27) combinations of training intensities increased motor drive compared to the control condition. The multi-joint training and testing exercise structure (g = 1.23; 95 % CI 0.79 to 1.67) was more effective in increasing motor drive (Qdf=2 = 14.15; p = 0.001) than the multi-single joint structure (g = 0.46; 95 % CI 0.06 to 0.85). Therefore, strength and power training with high volume and intensity associated with multi-joint training and testing combination of exercises seem to improve skeletal muscle motor drive in older adults effectively.

Effects of combined exercise training with sleep education in older adults with obstructive sleep apnea: protocol for a randomized clinical trial

Background

Obstructive sleep apnea (OSA) is a common disorder that affects approximately 1 billion people worldwide. Advanced age is a significant risk factor. Various treatment options have been explored to reduce the severity of OSA symptoms and physical exercise has emerged as a potential alternative therapy. Therefore, this study aims to investigate the effects of a combined exercise program with sleep education on sleep quality and on the severity of OSA in older adults.

Methods

This is a randomized clinical trial with two parallel groups that will involve individuals of both genders aged between 60 and 79 years who have an apnea-hypopnea index (AHI) of more than 15 events per hour and who have not received or are currently undergoing treatment for OSA. Older adults who have engaged in regular exercise in the last six months and individuals with contraindications to exercise will be excluded. The study will assess outcomes related to OSA, including AHI, oxygen desaturation index, minimum and mean oxyhemoglobin saturation, sleep efficiency, sleep latency, and the type of respiratory events. Additionally, sleep quality-related outcomes, daytime sleepiness, physical activity, physical fitness, aerobic capacity, cognitive status, anthropometric measures, and health-related quality of life will be analyzed. Participants will be randomized to two groups: a combined exercise group (involving both resistance and aerobic training) with sleep education, and a control group that will receive only educational recommendations for managing OSA. The intervention will last 12 weeks and will consist of three sessions per week, totaling 36 exercise sessions. Sample size calculation indicates a minimum number of 36 participants.

Discussion

If the hypothesis is confirmed, this clinical trial will indicate an effective non-pharmacological intervention for treating OSA in older adults. This intervention could be used as an adjunct to existing approaches designed to improve OSA management.

Clinical trail registration

Brazil Clinical Trials Registry (ReBEC), identifier RBR-9hk6pgz.

Agility performance in healthy older adults is associated with handgrip strength and force development: results from a 1-year randomized controlled trial

PURPOSE

Handgrip strength is considered as important indicator for general fitness in older adults. However, it does not notably reflect adaptations from whole-body training but may reflect adaptions of multicomponent exercise training. These approaches seem to be more functional and related to relevant daily tasks. Effects of multicomponent agility training on handgrip strength are analysed.

METHODS

Healthy older adults (N = 79, 69.3 ± 4.4 years, 64% female) were randomly assigned to an intervention (IG) or control group (CG). IG took part in a twice weekly 60 min multicomponent agility training for 12 months. Adherence rate of the participants was 75 ± 10 %.

RESULTS

Neither maximum handgrip strength (F_max) differed between groups (IG: 318 ± 97 N, CG: 302 ± 92 N) nor did it change after the intervention (IG: 315 ± 90 N, CG: 301 ± 97 N). Mixed ANOVA for F_max (F(1,49) = 0.018, p = 0.893) revealed no significant group × time interaction with an effect size of [Formula: see text]. Similar results were observed for rate of force development (RFD) (F(1,49) = 0.038, p = 0.847) with an effect size [Formula: see text] . RFD did not differ between groups in pre (IG: 876 ± 585 N/s, CG: 712 ± 303 N/s) and post (IG: 890 ± 424 N/s, CG: 702 ± 368 N/s) measurements. Correlation for ACE and F_max (r(64) = - 0.367, p = 0.005) and for RFD (r(64) = - 0.487, p < 0.001) was found to be negative.

CONCLUSION

A 1-year multicomponent agility training does not affect handgrip strength in healthy older adults. However, handgrip strength (F_max and RFD) is associated with agility, thus both handgrip strength indicators and agility might serve as local and functional vitality surrogates.

Determining the cortical, spinal and muscular adaptations to strength-training in older adults: A systematic review and meta-analysis

There are observable decreases in muscle strength as a result of ageing that occur from the age of 40, which are thought to occur as a result of changes within the neuromuscular system. Strength-training in older adults is a suitable intervention that may counteract the age-related loss in force production. The neuromuscular adaptations (i.e., cortical, spinal and muscular) to strength-training in older adults are largely equivocal and a systematic review with meta-analysis will serve to clarify the present circumstances regarding the benefits of strength-training in older adults. 20 studies entered the meta-analysis and were analysed using a random-effects model. A best evidence synthesis that included 36 studies was performed for variables that had insufficient data for meta-analysis. One study entered both. There was strong evidence that strength-training increases maximal force production, rate of force development and muscle activation in older adults. There was limited evidence for strength-training to improve voluntary-activation, the volitional-wave and spinal excitability, but strong evidence for increased muscle mass. The findings suggest that strength-training performed between 2 and 12 weeks increases strength, rate of force development and muscle activation, which likely improves motoneurone excitability by increased motor unit recruitment and improved discharge rates.

The influence of resistance training on neuromuscular function in middle-aged and older adults: A systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Deterioration of neuromuscular function is a major mechanism of age-related strength loss. Resistance training (RT) improves muscle strength and mass. However, the effects of RT on neuromuscular adaptations in middle-aged and older adults are unclear.

METHODS

Randomised controlled RT interventions (≥2 weeks) involving adults aged ≥50 years were identified. Primary outcome measures were voluntary activation (VA), electromyographic (EMG) activity during maximal voluntary contraction (MVC), and antagonist coactivation. Data were pooled using a weighted random-effect model. Sub-analyses were conducted by muscle or muscle group and health status of participants. Sensitivity analysis was based on study quality. P < 0.05 indicated statistical significance.

RESULTS

Twenty-seven studies were included. An effect was found for VA (standardised mean difference [SMD] 0.54, 0.01 to 1.07, P = 0.04), This result remained significant following sensitivity analysis involving only studies that were low risk of bias. Subgroup analyses showed an effect for plantar flexor VA (SMD 1.13, 0.20 to 2.06, P = 0.02) and VA in healthy participants (SMD 1.04, 0.32 to 1.76, P = 0.004). There was no effect for EMG activity or antagonist coactivation of any muscle group (P > 0.05).

DISCUSSION

Resistance training did not alter EMG activity or antagonist coactivation in older adults. Sensitivity analysis resulted in the effect for VA remaining significant, indicating that this finding was not dependent on study quality. Studies predominantly involved healthy older adults (78%), limiting the generalisability of these findings to clinical cohorts. Future research should determine the effects of RT on neuromuscular function in people with sarcopenia and age-related syndromes.

Acute Effects of Different Rest Intervals Between Sets of Resistance Exercise on Neuromuscular Fatigue in Trained Older Women

Jambassi Filho, JC, Gurjão, ALD, Prado, AKG, Gallo, LH, and Gobbi, S. Acute effects of different rest intervals between sets of resistance exercise on neuromuscular fatigue in trained older women. J Strength Cond Res 34(8): 2235-2240, 2020-The aim of this study was to investigate the acute effect of different rest intervals (RIs) between sets on total volume, time under tension, maximal voluntary contraction (MVC), and integrated electromyography (iEMG) activity of the vastus lateralis (VL) and vastus medialis (VM) muscles. Twenty-one resistance-trained older women (66.4 ± 4.4 years; 69.1 ± 11.4 kg; 157.5 ± 5.0 cm) completed 3 different test sessions, performed 48-72 hours apart, in a randomized and counterbalanced within-subjects design. In 2 test sessions, the participants performed 3 sets to voluntary exhaustion with loads that corresponded to 15 maximum repetitions, with either 1-minute RI (RI-1) or 3-minute RI (RI-3). In another test session, the participants remained at rest for 15 minutes. The total volume of exercise and time under tension for the RI-3 session was statistically higher (p ≤ 0.05) than the RI-1 session. Postexercise MVC for the RI-3 session showed significantly greater reductions (-7.8%; p ≤ 0.05) compared with the RI-1 and control sessions. No significant changes in postexercise iEMG activity of the VL and VM were shown for any of the sessions (all p > 0.05). The findings of this study suggest that different RIs between sets lead to different acute neuromuscular responses. The longer RI seemed to induce higher neuromuscular fatigue, likely due to higher total volume and time under tension. Thus, longer RI may be a strategy that possibly would lead to greater long-term gains in muscle strength and hypertrophy of the lower limbs in trained older women.

Effect of Weight Training with Pelvic Floor Muscle Training in Elderly Women with Urinary Incontinence

PURPOSE

To determine if weight training combined with pelvic floor muscle training is more efficient than pelvic floor muscle training alone for the treatment of urinary incontinence (UI) symptoms in elderly women.

METHOD

This was a two-arm, parallel, randomized controlled trial. Twenty-six women with stress UI participated in the study. The intervention group (IG) underwent training with moderate intensity weights combined with pelvic floor muscle training, whereas the control group (CG) only underwent pelvic floor muscle training. Intervention occurred twice a week over 12 weeks. The International Consultation on Incontinence Questionnaire-Short Form was used as the main measure. Scores of zero defined the absence of symptoms. The absence of symptoms was evaluated at 4 weeks, 12 weeks, and 1 month after the end of treatment. Moreover, activities related to UI and the use and change of daily protection were investigated.

RESULTS

The rate of absence of symptoms was significantly higher in IG after 4 weeks (58.3%) compared to CG (14.8%). The relative risk was 4.1 (95% confidence interval [CI] [1.08, 16.06]). Although no intention-to-treat analysis was performed, there was no difference in the evaluations after the interventions.

CONCLUSION

Compared to pelvic floor muscle training alone, the combination of weight training and pelvic floor muscle training provided earlier improvement of UI in elderly women.

Effects of Strength Training on Muscle Properties, Physical Function, and Physical Activity among Frail Older People: A Pilot Study

The aim of this study was to determine the effects of a 10-week strength training intervention on isometric strength, rate of force development (RFD), physical function (stair climbing, rising from a chair, and preferred and maximal walking speed), and physical activity among frail elderly people receiving home-care services. Thirty participants were randomly assigned (by sex) to a control group (CON) or a strength training group (ST) performing a supervised training programme using elastic bands, box-lifting, and body weight exercises twice per week. Twenty-three participants were selected to complete the study (age 84.9 ± 6.1 years). For the ST, only improvement in muscle properties was the peak RFD in leg extension (p=0.04). No significant differences were observed in muscle properties for the control group (CON) (p=0.16–1.00) or between groups (p=0.39–1.00). There were no changes within and between the groups in physical function (p=0.12–0.19) or physical activity levels (p=0.06–0.73). The results of this pilot study did not demonstrate greater improvements in muscle properties and physical function and improved physical activity after attending a home-based resistance program compared to physical activity advise; however, larger population studies should examine these findings. This trial is registered with ISRCTN10967873.

EFFECTS OF A MULTICOMPONENT EXERCISE PROGRAM ON THE FUNCTIONAL FITNESS IN ELDERLY WOMEN

ABSTRACT Introduction: Aging is inevitable and irreversible, but with the advancement of technology, life expectancy is increasing every year, bringing proposals for various interventions to improve the quality of life. One such intervention is physical exercise programs. Objectives: To investigate the impact of multicomponent training in circuits on functional autonomy parameters in elderly women. Methods: Elderly were recruited and distributed in two groups: trained (N = 16) and non-trained (N = 15). Those in the trained group performed 75-minute training sessions twice a week over a 56-week period. The resistance training included upper and lower limbs with a relative intensity of 70% of 1RM, exercises using body weight, stretching and specific tasks for agility, performed in a circuit form and totaling three passages. Participants underwent functional autonomy (FA) assessment by the protocol of the Latin American Developmental Group for Maturity, the 6-minute walk test (T6M), and the sit-and-reach (SR) test. Results: The trained group had a significant decrease in body weight (p=0.02) and body mass index (p=0.015). Significant improvements (p=0,009) were also observed in FA, SR, and T6M after the intervention Compared with the untrained group, the trained group also obtained significant differences in all functional parameters analyzed. Conclusion: A long-term multicomponent training program conducted on a circuit and applied twice a week was enough to improve multiple components of the functional autonomy of elderly women. Level of Evidence II; Prognostic studies - Investigating the effect of a patient characteristic on the outcome of disease.

TAXA DE DESENVOLVIMENTO DE FORÇA E ATIVAÇÃO NEURAL EM MULHERES PÓS-MENOPAUSADAS

RESUMO Introdução: O envelhecimento associa-se à redução da velocidade de contração e ativação das fibras musculares, influenciando a aptidão física e o desempenho funcional. Objetivo: Verificar o comportamento da taxa de desenvolvimento de força (TDF) e ativação neural em mulheres pós-menopausadas. Métodos: Vinte e quatro mulheres pós-menopausadas (63,2 ± 5,6 anos; 154,5 ± 7,3 cm e 64,7 ± 7,6 kg), funcionalmente independentes e fisicamente ativas, foram submetidas simultaneamente, à mensuração da força isométrica máxima e dos sinais eletromiográficos (EMG) dos seguintes músculos: vasto lateral (VL), reto femoral (RF) e vasto medial (VM), durante uma extensão unilateral do joelho do membro dominante. Tais resultados foram utilizados para calcular a TDF, o impulso contrátil, em intervalos de 20 ms nos primeiros 200 ms da contração muscular pelo uso da curva força/tempo, a taxa de ativação EMG (TAE) e a amplitude média EMG, em intervalos de 40 a 80 ms do início da integração EMG pelo uso da curva EMG/tempo. Resultados: Os valores da força variaram entre 29,19 a 86,04 N.m; a TDF variou de 1459,42 N.m.s-1 para 430,21 N.m.s-1 em 20 ms e 200 ms respectivamente, apontando valores decrescentes com o tempo; para o impulso foram observados valores entre 0,65 a 11,07 N.m.s; na mesma direção da TDF, a TAE apresentou valores decrescentes para o VL (1676,08 a 844,41 µVs-1), para o RF (1320,88 a 637,59 µVs-1) e para o VM (1747,63 a 914,09 µVs-1) em 20 e 200 ms, enquanto a amplitude EMG média teve valores de 33,77 a 50,32 µV para o VL, de 24,93 a 38,07 µV para o RF e de 37,07 a 54,78 µV para o VM em 40 ms e 80 ms, respectivamente. Conclusão: Em mulheres pós-menopausadas, a velocidade de aumento, a manutenção da força e a ativação EMG não são suficientes para manter TDF e TAE crescentes, demonstrando um possível risco de incapacidades funcionais e ocorrência de quedas.

Positive effects of 1-year football and strength training on mechanical muscle function and functional capacity in elderly men

PURPOSE

A decline in physical capacity takes place with increasing age that negatively affects overall physical function including work ability and the ability to perform typical activities of daily living (ADL). The overall aim of the present study was to determine the neuromuscular adaptations to long-term (1 year) football and strength training in older untrained adults, and to assess the concurrent effect on functional ADL capacity.

METHODS

Twenty-seven healthy elderly males (68.2 ± 3.2 years) were randomly assigned to 12 months of either recreational football training (FT: n = 10), strength training (ST: n = 9) or served as inactive controls (CON: n = 8). Recreational football training consisted of small-sided training sessions whereas strength training consisted of high intensity exercises targeting the lower extremity and upper body. Maximal thigh muscle strength and rate of force development (RFD) were assessed with isokinetic dynamometry, while postural balance and vertical jumping performance were evaluated using force plate analysis. Furthermore, functional ability was evaluated by stair-ascent and chair-rising testing.

RESULTS

A total of nine, nine and seven participants from FT, ST and CON, respectively, were included in the analysis. Both exercise regimens led to substantial gains in functional ability, evidenced by 24 and 18 % reduced stair-ascent time, and 32 and 21 % increased chair-rising performance in FT and ST, respectively (all P < 0.05). Long-term strength training led to increased concentric (14 %; P < 0.01) and isometric (23 %; P < 0.001) quadriceps and isometric hamstring strength (44 %; P < 0.0001), whereas football training mainly resulted in enhanced hamstring strength (18 %, P < 0.05) and RFD (89 %, P < 0.0001).

CONCLUSIONS

Long-term (1 year) strength training led to increased quadriceps and hamstring strength, whereas the adaptations to football training mainly included enhanced strength and rapid force capacity of the hamstring muscles. Gains in functional ability were observed in response to both training regimens, evidenced by reduced stair-ascent time and increased chair-rising performance. Long-term football exercise and strength training both appear to be effective interventional strategies to improve factors of importance for ADL by counteracting the age-related decline in lower limb strength and functional capacity among old male adults. This could potentially be a way to improve work ability of senior workers.

Strength training improves muscle aerobic capacity and glucose tolerance in elderly

The primary aim of this study was to investigate the effect of short-term resistance training (RET) on mitochondrial protein content and glucose tolerance in elderly. Elderly women and men (age 71 ± 1, mean ± SEM) were assigned to a group performing 8 weeks of resistance training (RET, n = 12) or no training (CON, n = 9). The RET group increased in (i) knee extensor strength (concentric +11 ± 3%, eccentric +8 ± 3% and static +12 ± 3%), (ii) initial (0-30 ms) rate of force development (+52 ± 26%) and (iii) contents of proteins related to signaling of muscle protein synthesis (Akt +69 ± 20 and mammalian target of rapamycin +69 ± 32%). Muscle fiber type composition changed to a more oxidative profile in RET with increased amount of type IIa fibers (+26.9 ± 6.8%) and a trend for decreased amount of type IIx fibers (-16.4 ± 18.2%, P = 0.068). Mitochondrial proteins (OXPHOS complex II, IV, and citrate synthase) increased in RET by +30 ± 11%, +99 ± 31% and +29 ± 8%, respectively. RET resulted in improved oral glucose tolerance measured as reduced area under curve for glucose (-21 ± 26%) and reduced plasma glucose 2 h post-glucose intake (-14 ± 5%). In CON parameters were unchanged or impaired. In conclusion, short-term resistance training in elderly not only improves muscular strength, but results in robust increases in several parameters related to muscle aerobic capacity.