Power training for older adults

Effects of maximal-versus submaximal-intent resistance training on functional capacity and strength in community-dwelling older adults: a systematic review and meta-analysis

The objective of this systematic review is to investigate the effects of different methods of resistance training (RT) on functional capacity in older adults. A systematic literature search was conducted using PubMed, SPORTDiscus, Web of Science, CINAHL, Cochrane CENTRAL, ClinicalTrials.gov databases, from inception to December 2021. Eligibility criteria consisted of randomised control trials (RCT’s) involving maximal-intent resistance training (MIRT), where participants (aged 60+) had specific instruction to move ‘as fast as possible’ during the concentric phase of the exercise. Twelve studies were included within the meta-analysis. Divided into functional capacity and strength-related outcomes; Improvements were evident for timed-up-and-go (p = 0.001, SMD: − 1.74 [95% CI − 2.79, − 0.69]) and knee extension one-repetition maximum (1RM) (p = 0.01, SMD: − 1.21, [95% CI − 2.17, − 0.25]), both in favour of MIRT, as well as in 30 s sit-to-stand in favour of T-STR (p = 0.04, SMD: 3.10 [95% CI 0.07, 6.14]). No statistical significance was found for combined functional capacity outcomes (p = 0.17, SMD: − 0.84, [95% CI − 2.04, 0.37]), with near-significance observed in strength-related outcomes (p = 0.06. SMD: − 0.57, [95% CI − 1.16, 0.02]) favouring MIRT. Heterogeneity for FC-outcomes was observed as Tau² = 4.83; Chi = 276.19, df = 14, I² = 95%, and for strength-outcomes Tau² = 1.290; Chi = 109.65, df = 115, I² = 86%. Additionally, MIRT elicited substantial clinically meaningful improvements (CMI) in Short Physical Performance Battery (SPPB) scores but fell short of CMI in 400 m walk test by 0.6 s. In conclusion, this systematic review highlights the lack of sufficient and quality evidence for maximal- versus submaximal-intent resistance training on functional capacity and strength in community-dwelling older adults. Study limitations revolved around lack of research, low quality (“low” PEDro score), and largely due to the fact many comparison studies did not match their loads lifted (1500 kg vs. 500 kg), making comparisons not possible.

Correlation between sit-to-stand ability, dynamic balance, gait speed, and quality of life in stroke population: a non-randomized pilot study

Background

“Sit to stand” being a prerequisite for walking, the inability of patients to perform it can result in institutionalization, impaired functioning and mobility in activities of daily living. There was a need to find out whether “sit to stand” ability correlates with gait speed, dynamic balance, and quality of life in stroke patients. It is a pilot study in which sixteen sub-acute and chronic stroke (˃ 6 months) patients aged 45 to 65 years with the ability to walk at least 10 m, Mini Mental State Examination (MMSE) score ˃ 27 were included. Patients with musculoskeletal impairments of lower extremity which would affect walking were excluded from the study. Each patient performed five times sit to stand (5TSTS) from a standard chair and time taken was recorded. Timed up and go (TUG) test and 10-m walk test (10MWT) were used to measure the dynamic balance and gait speed respectively. Stroke Adapted Sickness Impact Profile-30 (SASIP-30) scale was used to determine the quality of life of the patients.

Results

Correlation between the outcomes of the variables was analyzed using Pearson correlation co-efficient. The 5TSTS scores showed strong positive correlation to TUG (r = 0.823, P < .000) and SASIP-30 (r = 0.841, P < .000). However, moderately strong negative relationship was found between 5TSTS and gait speed (r = −0.639, P < .008).

Conclusion

The study concludes that change in the 5TSTS performance can affect motor functions like dynamic balance and gait as well as quality of life. Exercise training focusing on sit-to-stand ability may also influence activities of daily living (ADLs) after stroke.

Total hip arthroplasty versus progressive resistance training in patients with severe hip osteoarthritis: protocol for a multicentre, parallel-group, randomised controlled superiority trial

INTRODUCTION

Hip osteoarthritis (OA) is the leading cause for total hip arthroplasty (THA). Although, being considered as the surgery of the century up to 23% of the patients report long-term pain, and deficits in physical function and muscle strength may persist after THA. Progressive resistance training (PRT) appears to improve multiple outcomes moderately in patients with hip OA. Current treatment selection is based on low-level evidence as no randomised controlled trials have compared THA to non-surgical treatment. The primary aim of this trial is to investigate whether THA followed by standard care is superior to 12 weeks of supervised PRT followed by 12 weeks of optional unsupervised PRT for improving hip pain and function in patients with severe hip OA.

METHODS AND ANALYSIS

This is a protocol for a multicentre, parallel-group, assessor-blinded, randomised controlled superiority trial conducted at four hospitals across three healthcare regions in Denmark. 120 patients aged ≥50 years with clinical and radiographic hip OA found eligible for THA by an orthopaedic surgeon will be randomised to THA followed by standard care, or 12 weeks of PRT (allocation 1:1). The primary outcome will be change in patient-reported hip pain and function, measured using the Oxford Hip Score, from baseline to 6 months after initiating the treatment. Key secondary outcomes will be change in the Hip disability and Osteoarthritis Outcome Score subscales, University of California Los Angeles Activity Score, 40 m fast-paced walk test, 30 s chair stand test and occurrence of serious adverse events. Patients declining participation in the trial will be invited into a prospective observational cohort study.

ETHICS AND DISSEMINATION

The trial has been approved by The Regional Committees on Health Research Ethics for Southern Denmark (Project-ID: S-20180158). All results will be presented in peer-reviewed scientific journals and international conferences.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov (NCT04070027).

Foot-ankle functional outcomes of using the Diabetic Foot Guidance System (SOPeD) for people with diabetic neuropathy: a feasibility study for the single-blind randomized controlled FOotCAre (FOCA) trial I

BACKGROUND

Diabetic neuropathy dramatically affects musculoskeletal structure and function of the lower limbs by impairing their muscle strength and mobility. Specific muscle strengthening through physiotherapy strategies appears to be promising; however, adherence to physiotherapy treatment is low in people with chronic diseases. Thus, an internet-based foot-ankle exercise program was created as a potential telerehabilitation alternative for people with diabetes to improve their self-monitoring and self-care management. This study assessed the feasibility, safety, acceptability, and changes in foot health and neuropathy symptoms in people with diabetes after 12 weeks of the intervention program with the Sistema de Orientação ao Pé diabético - Diabetic Foot Guidance System (SOPeD).

METHODS

Fourteen individuals were recruited and randomized to either the usual care (control group) or usual care plus an internet-based foot-ankle exercise program through SOPeD (intervention group) three times per week for 12 weeks. For feasibility, we assessed contact and recruitment rates per week; program adherence, determined as completing over 70% of the 36 sessions; and participant satisfaction and safety assessed through a questionnaire and scored on a 5-point Likert scale. We assessed changes in neuropathy symptoms and foot health and functionality from baseline to 12 weeks estimating differences or median of differences and 95% confidence intervals in the intervention group.

RESULTS

In 24 weeks, of the 822 patients in the database, 192 were contacted, 65 were assessed for eligibility, and 20 were considered eligible. The recruitment rate was 0.83 participants per week. Fourteen out of the 20 eligible participants agreed to participate, resulting in recruitment success of 70%. Adherence to the program was 66.7%, and there was no dropout. Participants' median level of satisfaction was 5.0 (IQR: 4.5-5.0) and perceived safety was 5.0 (IQR: 5.0-5.0).

CONCLUSION

The internet-based foot-ankle exercise program using SOPeD is feasible, satisfactory, and safe. Although this study had moderate adherence and a zero-dropout rate, recruitment needs to be improved in the larger trial.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04011267 . Registered on 8 July 2019.

The effects of ageing on functional capacity and stretch-shortening cycle muscle power

[Purpose] To examine the effects of age and gender in an ageing population with respect to functional decline and the relationship between muscle power and functional capacity. [Participants and Methods] The cohort (N=154) was subdivided into youngest-old (65–70 years.; n=62), middle-old (71–75 years.; n=46), and oldest-old (76–81 years.; n=46). Measures of mechanical muscle function included countermovement jump height, muscle power, leg strength and grip strength. Functional performance-based measures included heel-rise, postural balance, Timed Up and Go, and gait speed. [Results] The oldest-old performed significantly worse than the middle-old, whereas the youngest-old did not outperform the middle-old to the same extent. Increased contribution of muscle power was observed with increasing age. Males had consistently higher scores in measures of mechanical muscle function, whereas no gender differences were observed for functional capacity. [Conclusion] The age-related decline in functional capacity appears to accelerate when approaching 80 years of age and lower limb muscle power seems to contribute to a greater extent to the preservation of functional balance and gait capacity at that stage. Males outperform females in measures of mechanical muscle function independent of age, while the findings give no support for the existence of gender differences in functional capacity.

Of Sound Mind and Body: Exploring the Diet-Strength Interaction in Healthy Aging

Strength is a vital component of healthy aging. However, “strength” comes in different forms (includes both physical and mental aspects) and can look different at various phases of adult life. Healthy eating and regular exercise are clearly important pillars for strength. This paper proposes a framework that underlines the value of protein foods and resistance exercise for aging strong.

Effectiveness of a resistance training program on physical function, muscle strength, and body composition in community-dwelling older adults receiving home care: a cluster-randomized controlled trial

Background

Aging is associated with reduced muscle mass and strength leading to impaired physical function. Resistance training programs incorporated into older adults' real-life settings may have the potential to counteract these changes. We evaluated the effectiveness of 8 months resistance training using easily available, low cost equipment compared to physical activity counselling on physical function, muscle strength, and body composition in community-dwelling older adults receiving home care.

Methods

This open label, two-armed, parallel group, cluster randomized trial recruited older adults above 70 years (median age 86.0 (Interquartile range 80-90) years) receiving home care. Participants were randomized at cluster level to the resistance training group (RTG) or the control group (CG). The RTG trained twice a week while the CG were informed about the national recommendations for physical activity and received a motivational talk every 6th week. Outcomes were assessed at participant level at baseline, after four, and 8 months and included tests of physical function (chair rise, 8 ft-up-and-go, preferred- and maximal gait speed, and stair climb), maximal strength, rate of force development, and body composition.

Results

Twelve clusters were allocated to RTG (7 clusters, 60 participants) or CG (5 clusters, 44 participants). The number of participants analyzed was 56-64 (6-7 clusters) in RTG and 20-42 (5 clusters) in CG. After 8 months, multilevel linear mixed models showed that RTG improved in all tests of physical function and maximal leg strength (9-24%, p = 0.01-0.03) compared to CG. No effects were seen for rate of force development or body composition.

Conclusion

This study show that resistance training using easily available, low cost equipment is more effective than physical activity counselling for improving physical function and maximal strength in community-dwelling older adults receiving home care.

Trial registration

ISRCTN1067873.

Effect of a 12-week mixed power training on physical function in dynapenic-obese older men: does severity of dynapenia matter?

INTRODUCTION

Mobility disability affects nearly 15% of people aged 65 or over worldwide. Excess weight or obesity (OB), along with an accentuated loss of muscle strength (dynapenia), is recognized to be one of the most common risk factors for mobility impairment among the elderly.

OBJECTIVE

To investigate the effect of a 12-week mixed power training (MPT high-velocity resistance training mixed with functional exercises) on physical function in obese older men exhibiting different severities of dynapenia.

METHODS

Community-dwelling older men (69 ± 6 years) were assigned to the study if they were considered obese (OB, fat mass ≥ 25% body weight, BW) and to one of the two groups according to severity of dynapenia [(handgrip strength-HS)/BW]: type 1(OB-DY1) or type 2(OB-DY2), < 1 or 2SD from a young reference group. Participants followed a 12-week MPT, three times/week, 75 min/session. Main outcomes included the performance on the 4-m and 6-min walking tests, Timed Up and Go, stair and balance tests.

RESULTS AND DISCUSSION

At baseline, OB-DY1 performed better than OB-DY2 in all functional tests (p < 0.05). Following the intervention, medium-to-large training effect size (ES) were observed for fat (ES = 0.21) and lean (ES = 0.32, p < 0.001) masses, functional performance (ES 0.11-0.54, p < 0.05), HS (ES = 0.10, p < 0.05) and lower limb muscle strength (ES = 0.67, p < 0.001) and power (ES = 0.60, p < 0.05). Training-by-group interaction showed that OB-DY1 lost more FM (ES = 0.11, p = 0.03) and OB-DY2 improved more HS (ES = 0.19, p = 0.006) than their counterparts.

CONCLUSIONS

Seniors with obesity and severe dynapenia have poorer physical function than those in the early stage of dynapenia. Both seem to benefit from a high-velocity resistance training mixed with functional exercises, although by slightly different pathways.

Effects of linear periodization versus daily undulating periodization on neuromuscular performance and activities of daily living in an elderly population

BACKGROUND

Periodization is a systematic training calendar designed to provide variations in performance targeting, while maximizing results and reducing the potential for overtraining. When provided across multiple weeks, termed a mesocycle, it may also incorporate active recovery periods using specified drills designed to translate neuromuscular gains into targeted functional abilities. There are a number of models that can be used when applying periodization to resistance training (RT). Among the most common are the linear (LP) and daily fixed non-linear (NLP) models. It is currently unknown whether an optimal periodization strategy exists that will maximize benefits for older adults; therefore, we compared the impact of these two periodization models on neuromuscular and functional measures in a group of older persons living independently in the community.

METHODS

Thirty-six older adults, 58-80 years of age, were randomly assigned to either a LP (n = 16; 69.3 ± 4.6 y) or NLP (n = 14; 68.9 ± 6.7 y) group. The LP group performed 12 weeks of training comprised of separate 4-week strength and power training cycles, each followed by a 2-week recovery period incorporating translational exercises. The NLP group performed the strength, power, and translational training on three separate days during the week. Neuromuscular testing included seated chest press and leg press strength and power tests, while physical function testing included the gallon jug shelf test, laundry transfer test, floor stand-up, chair-to-stand test, and 8 foot timed up-and-go.

RESULTS

3 (time) × 2 (sex) × 2 (group) repeated measures ANOVA revealed both periodization strategies were equally effective at inducing neuromuscular and functional improvements and that men generally produced more strength and power than women.

CONCLUSIONS

Both LP and NLP can be used to improve strength, power, and functional performance in healthy untrained older adults when strength, power and functional training cycles are involved. Therefore, personal preference and variety should be considered when deciding which approach to use, provided high-speed power and translational recovery components are included.

MODERATE INTENSITY IS A BETTER STIMULUS TO INDUCE QUADRIPECS FEMORIS POWER IN ELDERLY ADULTS

ABSTRACT Introduction: The best strategy for improving knee extensor power, a major functional capacity indicator in older adults, is power training. Nonetheless, the training intensity required to induce optimal gains is yet to be found. Objective: Our purpose was to compare knee extensor peak power responses between low, moderate, and high intensity load conditions (30%, 50% and 70% of 1RM). Methods: Thirteen sedentary elderly women performed six knee extensions in each load condition, calculating knee extensor mechanical work/power output and knee extension peak angular velocity. Results: No difference in peak power was found between the high (207.0 ± 68.1 W) and moderate (206.1 ± 71.6 W) load conditions (p = 0.994), and both had higher values (p ≤0.004) than the low intensity condition (135.6 ± 56.3 W). Conclusion: Moderate load at 50% of 1RM appears to be the preferred strategy for inducing knee extensor power output because in contrast with the high intensity condition, the moderate load yielded higher angular peak velocity, which is also a functional indicator. Level of Evidence ll; Therapeutic studies - Investigating treatment results.

Feasibility of a community-based Functional Power Training program for older adults

Purpose

Community-based programs can increase and sustain physical activity participation in older adults, even for those who are physically frail. We studied the feasibility and potential effect of a 12-week structured Functional Power Training (FPT) program involving high velocities and low loads for older adults conducted in a common area of their housing estate.

Patients and methods

The structured FPT program was conducted in collaboration with a health promotion social enterprise and a community service provider based in a public housing site. We recruited nine inactive residents as participants to the single, group-based, twice-weekly program. Attendance and adverse event(s) were recorded throughout the program. The Short Physical Performance Battery, Timed Up and Go (TUG), and 30s Sit-to-Stand tests were used to assess functional outcomes pre- and postprogram. The FRAIL Scale was used to assess their frailty status, and a postprogram experience survey was conducted.

Results

Eight subjects (aged 74±10 years) completed the program with an average overall attendance of 90.3%, with at least five participants present for each session. Changes in functional outcomes showed a moderate-to-large effect with significant improvement in TUG (p<0.01). In addition, participants either reversed or maintained their frailty status (p<0.01). Overall, the program was perceived to be well structured, engaging, as well as providing physical and psychosocial benefits. No exercise-related adverse events occurred during the program, and participants were keen to recommend this program to others.

Conclusion

Community-based structured FPT is safe and feasible for frail older adults, with the potential to improve function and reverse frailty status.

Differences in muscle adaptation to a 12-week mixed power training in elderly men, depending on usual protein intake

INTRODUCTION

Normal aging is often associated with a decline of muscle mass (MM), strength (MS) and quality (MQ: MS/MM), leading to functional incapacities. This aging-related deterioration of muscles may involve a decreased protein intake. Mixed power training has been recently shown to induce positive effects on MM, MS and MQ. However, to our knowledge, no study has examined if muscle adaptations following mixed power training could be influenced by the daily amount of protein ingested in elderly men.

METHODS

Twenty-one men completed the intervention and were divided into 2 groups based on their usual protein intake: PROT 1.1- (<1.1 g·kg^-1·d^-1 [n = 10; 73 ± 3 years]) and PROT 1.2+ (>1.2 g·kg^-1·d^-1 [n = 11; 73 ± 3 years]). Body composition (DXA: lean and fat masses), MS (1-maximal repetition on leg-press and handgrip strength), MQ (MS/body mass and MS/lower limb lean mass), functional capacities (Short Physical Performance Battery/Senior Fitness Test), dietary intake (3-day food record) and energy expenditure (accelerometer; 7 days) were measured. Mixed power training intervention consisted in power and functional exercises (12 weeks; 3 times/week; 1 h/session).

RESULTS

Lower limb MS increase in the PROT 1.2+ group was greater from that of the PROT 1.1- group when normalized to lower limbs lean mass (p = 0.036). In addition, a trend for greater gain in lower limb MS normalized to body mass (p = 0.053) was observed in the PROT 1.2+.

CONCLUSION

To optimize mixed power training effects on muscle function, healthy older men should ingest daily at least 1.2 g·kg^-1·d^-1 of protein. These beneficial effects of a higher usual protein intake were observed especially for MQ, which is one of the best predictors of functional capacities in older adults.

Effects of Resistance Training on Lower-Extremity Muscle Power in Middle-Aged and Older Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Resistance training (RT) has been investigated as a potential intervention strategy for improving muscle function, but the effects on lower-extremity muscle power in middle-aged and older adults have not been systematically reviewed.

OBJECTIVE

The aim of this meta-analysis is to provide a quantitative estimate of the effect of RT on lower-extremity muscle power in middle-aged and older adults and to examine independent moderators of this relationship.

METHODS

Randomized controlled trials that examined the effects of RT on either leg press (LP) or knee extension (KE) muscle power in adults aged ≥50 years were included. Data were aggregated with meta-analytic techniques, and multi-level modeling was used to adjust for nesting effects. A total of 52 effects from 12 randomized controlled trials were analyzed with a random-effects model to estimate the effect of RT on lower-extremity muscle power. A multiple-regression analysis was conducted to examine independent moderators of the mean effect.

RESULTS

The adjusted aggregated results from all studies indicate that RT has a small-to-moderate effect on lower-extremity muscle power (Hedges' d = 0.34, 95% confidence interval [CI] 0.25-0.43), which translated to 54.90 watts (95 % CI 40.37-69.43). Meta-regression analyses indicated that high-velocity RT was superior to traditional RT (Δ = 0.62 vs. 0.20, respectively) for increasing lower-extremity muscle power. In addition, training volume significantly moderated the effect of RT on muscle power.

CONCLUSION

The findings from this meta-analysis indicate that RT is an efficacious intervention strategy for improving LP and KE muscle power in adults aged ≥50 years. Training mode and volume independently moderate the effect of RT on lower-extremity muscle power, and should be considered when prescribing RT exercise for middle-aged and older adults.

Effects of different doses of high-speed resistance training on physical performance and quality of life in older women: a randomized controlled trial

OBJECTIVE

This study aimed to compare the effects of two frequencies of high-speed resistance training (HSRT) on physical performance and quality of life of older women.

METHODS

A total of 24 older women participated in a 12-week HSRT program composed of either two or three sessions/week (equated for volume and intensity). Women were randomized into three arms: a control group (CG, n=8), a resistance training group performing two sessions/week (RT2, n=8), and a resistance training group performing three sessions/week (RT3, n=8). The training program for both experimental groups included exercises that required high-speed concentric muscle actions.

RESULTS

No baseline differences were observed among groups. Compared with the CG, both training groups showed similar small to moderate improvements (P<0.05) in muscle strength, power, functional performance, balance, and quality of life.

CONCLUSION

These results suggest that equated for volume and intensity, two and three training sessions/week of HSRT are equally effective for improving physical performance and quality of life of older women.

Effect of traditional resistance and power training using rated perceived exertion for enhancement of muscle strength, power, and functional performance

The present study compared the effects of 12 weeks of traditional resistance training and power training using rated perceived exertion (RPE) to determine training intensity on improvements in strength, muscle power, and ability to perform functional task in older women. Thirty healthy elderly women (60-75 years) were randomly assigned to traditional resistance training group (TRT; n = 15) or power training group (PT; n = 15). Participants trained twice a week for 12 weeks using six exercises. The training protocol was designed to ascertain that participants exercised at an RPE of 13-18 (on a 6-20 scale). Maximal dynamic strength, muscle power, and functional performance of lower limb muscles were assessed. Maximal dynamic strength muscle strength leg press (≈58 %) and knee extension (≈20 %) increased significantly (p < 0.001) and similarly in both groups after training. Muscle power also increased with training (≈27 %; p < 0.05), with no difference between groups. Both groups also improved their functional performance after training period (≈13 %; p < 0.001), with no difference between groups. The present study showed that TRT and PT using RPE scale to control intensity were significantly and similarly effective in improving maximal strength, muscle power, and functional performance of lower limbs in elderly women.

Preoperative progressive explosive-type resistance training is feasible and effective in patients with hip osteoarthritis scheduled for total hip arthroplasty--a randomized controlled trial

OBJECTIVE

To investigate the efficacy and feasibility of progressive explosive-type resistance training (RT) in patients with osteoarthritis (OA) of the hip scheduled for total hip arthroplasty (THA).

METHOD

Randomized controlled trial (1:1) in patients diagnosed with hip OA and scheduled for THA. The intervention group (IG) performed supervised preoperative progressive explosive-type RT twice a week for 10 weeks; four exercises (hip/thigh) performed in three series each (8-12 repetition maximum). The control group (CG) received 'care as usual'. Efficacy was reported as the between-group difference in the Hip Osteoarthritis Outcome Score (HOOS) (primary endpoint; ADL function), and leg muscle power at post intervention follow-up immediate before surgery. Intention-to-treat analyses were performed in a multilevel regression model adjusting for baseline, sex, age and weight. Feasibility was reported as adherence, exercise related pain and adverse effects. Post-surgical follow up will be reported separately. ClinicalTrials.gov registration: NCT01164111.

RESULTS

Eighty patients (age 70.4 ± 7.6 years, BMI 27.8 ± 4.6, 52 females (65%) were included. Adherence was high (93%) with acceptable exercise related pain (VAS score ≤ 5) reported in 83% of sessions and no adverse events. Changes in HOOS 'function' was 10.0 points 95%CI [4.7; 15.3] higher in IG compared to CG (P < 0.001). For all the remaining HOOS subscales IG scored significantly better (P < 0.03) and had higher leg extension muscle power (P < 0.0001) compared to CG.

CONCLUSION

Progressive explosive-type RT was feasible in the included group of hip OA patients scheduled for THA and resulted in significant improvement in self-reported outcomes and increased leg muscle power.

High-intensity versus low-intensity physical activity or exercise in people with hip or knee osteoarthritis

BACKGROUND

Exercise or physical activity is recommended for improving pain and functional status in people with knee or hip osteoarthritis. These are complex interventions whose effectiveness depends on one or more components that are often poorly identified. It has been suggested that health benefits may be greater with high-intensity rather than low-intensity exercise or physical activity.

OBJECTIVES

To determine the benefits and harms of high- versus low-intensity physical activity or exercise programs in people with hip or knee osteoarthritis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; issue 06, 2014), MEDLINE (194 8 to June 2014) , EMBASE (198 0 to June 2014), CINAHL (1982 to June 2014), PEDro (1929 to June 2014), SCOPUS (to June 2014) and the World Health Organization (WHO) International Clinical Registry Platform (to June 2014) for articles, without a language restriction. We also handsearched relevant conference proceedings, trials, and reference lists and contacted researchers and experts in the field to identify additional studies.

SELECTION CRITERIA

We included randomized controlled trials of people with knee or hip osteoarthritis that compared high- versus low-intensity physical activity or exercise programs between the experimental and control group.High-intensity physical activity or exercise programs training had to refer to an increase in the overall amount of training time (frequency, duration, number of sessions) or the amount of work (strength, number of repetitions) or effort/energy expenditure (exertion, heart rate, effort).

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility and extracted data on trial details. We contacted authors for additional information if necessary. We assessed the quality of the body of evidence for these outcomes using the GRADE approach.

MAIN RESULTS

We included reports for six studies of 656 participants that compared high- and low-intensity exercise programs; five studies exclusively recruited people with symptomatic knee osteoarthritis (620 participants), and one study exclusively recruited people with hip or knee osteoarthritis (36 participants). The majority of the participants were females (70%). No studies evaluated physical activity programs. We found the overall quality of evidence to be low to very low due to concerns about study limitations and imprecision (small number of studies, large confidence intervals) for the major outcomes using the GRADE approach. Most of the studies had an unclear or high risk of bias for several domains, and we judged five of the six studies to be at high risk for performance, detection, and attrition bias.Low-quality evidence indicated reduced pain on a 20-point Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain scale (mean difference (MD) -0.84, 95% confidence interval (CI) -1.63 to -0.04; 4% absolute reduction, 95% CI -8% to 0%; number needed to treat for an additional beneficial outcome (NNTB) 11, 95% CI 14 to 22) and improved physical function on the 68-point WOMAC disability subscale (MD -2.65, 95% CI -5.29 to -0.01; 4% absolute reduction; NNTB 10, 95% CI 8 to 13) immediately at the end of the exercise programs (from 8 to 24 weeks). However, these results are unlikely to be of clinical importance. These small improvements did not continue at longer-term follow-up (up to 40 weeks after the end of the intervention). We are uncertain of the effect on quality of life, as only one study reported this outcome (0 to 200 scale; MD 4.3, 95% CI -6.5 to 15.2; 2% absolute reduction; very low level of evidence).Our subgroup analyses provided uncertain evidence as to whether increased exercise time (duration, number of sessions) and level of resistance (strength or effort) have an impact on the exercise program effects.Three studies reported withdrawals due to adverse events. The number of dropouts was small. Only one study systematically monitored adverse effects, but four studies reported some adverse effects related to knee pain associated with an exercise program. We are uncertain as to whether high intensity increases the number of adverse effects (Peto odds ratio 1.72, 95% CI 0.51 to 5.81; - 2% absolute risk reduction; very low level of evidence). None of the included studies reported serious adverse events.

AUTHORS' CONCLUSIONS

We found very low-quality to low-quality evidence for no important clinical benefit of high-intensity compared to low-intensity exercise programs in improving pain and physical function in the short term. There was insufficient evidence to determine the effect of different types of intensity of exercise programs.We are uncertain as to whether higher-intensity exercise programs may induce more harmful effects than those of lower intensity; this must be evaluated by further studies. Withdrawals due to adverse events were poorly monitored and not reported systematically in each group. We downgraded the evidence to low or very low because of the risk of bias, inconsistency, and imprecision.The small number of studies comparing high- and low-intensity exercise programs in osteoarthritis underscores the need for more studies investigating the dose-response relationship in exercise programs. In particular, further studies are needed to establish the minimal intensity of exercise programs needed for clinical effect and the highest intensity patients can tolerate. Larger studies should comply with the Consolidated Standards of Reporting Trials (CONSORT) checklist and systematically report harms data to evaluate the potential impact of highest intensities of exercise programs in people with joint damage.

Sarcopenic obesity and complex interventions with nutrition and exercise in community-dwelling older persons--a narrative review

One of the many threats to independent life is the age-related loss of muscle mass and muscle function commonly referred to as sarcopenia. Another important health risk in old age leading to functional decline is obesity. Obesity prevalence in older persons is increasing, and like sarcopenia, severe obesity has been consistently associated with several negative health outcomes, disabilities, falls, and mobility limitations. Both sarcopenia and obesity pose a health risk for older persons per se, but in combination, they synergistically increase the risk for negative health outcomes and an earlier onset of disability. This combination of sarcopenia and obesity is commonly referred to as sarcopenic obesity. The present narrative review reports the current knowledge on the effects of complex interventions containing nutrition and exercise interventions in community-dwelling older persons with sarcopenic obesity. To date, several complex interventions with different outcomes have been conducted and have shown promise in counteracting either sarcopenia or obesity, but only a few studies have addressed the complex syndrome of sarcopenic obesity. Strong evidence exists on exercise interventions in sarcopenia, especially on strength training, and for obese older persons, strength exercise in combination with a dietary weight loss intervention demonstrated positive effects on muscle function and body fat. The differences in study protocols and target populations make it impossible at the moment to extract data for a meta-analysis or give state-of-the-art recommendations based on reliable evidence. A conclusion that can be drawn from this narrative review is that more exercise programs containing strength and aerobic exercise in combination with dietary interventions including a supervised weight loss program and/or protein supplements should be conducted in order to investigate possible positive effects on sarcopenic obesity.

The effect of muscle power training with elastic band on blood glucose, cytokine, and physical function in elderly women with hyperglycemia

[Purpose]

The purpose of this study was to identify the effects of muscle power training with elastic band on body composition, glucose relation factor, and physical function in elderly women with hyperglycemia.

[Methods]

A total of 16 elderly women volunteered to participate in this study as subjects, and they were randomly assigned into one of the following two groups: muscle power training group (MPT: n = 8) and control group (CON: n = 8). The muscle power training group took exercise program using elastic band for 12 weeks, and the other group did not receive any exercise program during the same period. Before and after the experiment, both of the two groups received measurement in body composition (BMI, %Fat, skeletal muscle mass), glucose, cytokine (interleukin 6, adiponectin), and physical function (IPPB, grip strength). With these methods, the following conclusions were achieved.

[Results]

The results showed significant increases in adiponectin (p = 0.006), interleukin 6 (p = 0.018), SPPB (p = 0.024), and grip strength (P=.014). Blood glucose was significantly decreased in exercise group than contruo group.

[Conclusion]

It shows that the muscle power training with elastic band can give positive effects in elderly women with hyperglycemia.

Velocity during Strength and Power Training of the Ankle Plantar and Dorsiflexor Muscles in Older Patients Attending Day Hospital Rehabilitation

Power training has been proposed as a more effective type of resistance training for older adults for functional performance. It is not yet known whether older adults respond appropriately to instructions for power versus strength training. The purpose of this study was to determine the velocity during strength and power training, with elastic resistance bands, in older adults attending a geriatric rehabilitation day program. It was hypothesized that power training would be faster than strength training, but that there would be large interindividual differences. Nine older patients (70 to 86 years) performed power and strength training of the ankle dorsiflexor and plantar flexor muscles using elastic resistance bands. Training sessions were filmed to assess the velocity of training. Power training occurred at faster velocities as compared to strength training (P < 0.01) for both muscle groups. However, a wide variation was observed between participants in the training velocities. Older adults attending geriatric rehabilitation do have the potential to develop faster contractions during power training as compared to strength training. Nevertheless, the actual velocities achieved differed between individuals. This could explain some of the mixed findings of studies on power training. Hence, researchers should monitor velocity when comparing different types of resistance training.

Physical exercise and sarcopenia in older people: position paper of the Italian Society of Orthopaedics and Medicine (OrtoMed)

Sarcopenia is the age-associated loss of skeletal muscle mass and function. It is a major clinical problem for older people and research in understanding of pathogenesis, clinical consequences, management, and socioeconomic burden of this condition is growing exponentially. The causes of sarcopenia are multifactorial, including inflammation, insulin resistance, changing endocrine function, chronic diseases, nutritional deficiencies and low levels of physical activity. Operational definition of sarcopenia combines assessment of muscle mass, muscle strength and physical performance. The diagnosis of sarcopenia should be based on having a low appendicular fat free mass in combination with low handgrip strength or poor physical functioning. Imaging techniques used for estimating lean body mass are computed tomography, magnetic resonance imaging, bioelectrical impedance analysis and dual energy X-ray absorptiometry, the latter considered as the preferred method in research and clinical use. Pharmacological interventions have shown limited efficacy in counteracting the age-related skeletal muscle wasting. Recent evidence suggests physical activity and exercise, in particular resistance training, as effective intervention strategies to slow down sarcopenia. The Italian Society of Orthopaedics and Medicine (Or-toMed) provides this position paper to present the update on the role of exercise on sarcopenia in the elderly.

Power training in patients with knee osteoarthritis: a pilot study on feasibility and efficacy

PURPOSE

To explore the feasibility and efficacy of using a power training exercise programme for the quadriceps femoris (QF) in elderly women with knee osteoarthritis (OA).

METHOD

A one-group quasi-experimental design with pre- and post-intervention measurements was conducted on 17 older adult women with knee OA pain. A bilateral QF exercise programme (24 sessions over 8 weeks) consisting of 3 series of 10 repetitions of flexion-extension as fast as possible at 40% of their one-repetition maximum (1RM) was performed in an outpatient physiotherapy clinic. The primary outcome measures were the knee function and associated problems using the Knee injury Osteoarthritis Outcome Score (KOOS) questionnaire and the weekly mean pain score from pain diaries using a visual analogue scale (VAS). QF strength (QFS), power (QFP) and work (QFW) were measured with an isokinetic dynamometer as secondary outcomes.

RESULTS

Significant improvements (p<0.05) were noted on the five categories of the KOOS. Significant decrease (p<0.01) was noted in pain intensity on VAS. QFP and QFW increased significantly on both sides (p<0.05). Exercise compliance was 99.5% for 16 participants.

CONCLUSIONS

A short power-training exercise programme is a feasible training modality for patients with knee OA, and significant functional improvements can be achieved. Further studies must be conducted to better understand the effects of the programme parameters and the generalizability of the findings.

Influência do treinamento da potência muscular sobre a capacidade de execução de tarefas motoras em mulheres idosas

INTRODUÇÃO: A manutenção da capacidade de geração de potência muscular é fator preponderante para a independência física e funcional do idoso. OBJETIVO: Avaliar o efeito de um programa de treinamento contra resistência em velocidade (PTCRV) sobre a potência muscular e o desempenho em tarefas motoras em idosas. MÉTODOS: 58 voluntárias sedentárias e fisicamente independentes foram divididas em dois subgrupos: 31 pertencentes ao grupo intervenção (GI), 68,7±5,2 anos de idade e 27 ao grupo controle (GC) 67,7±3,8 anos de idade. O GI foi submetido a um programa de 24 sessões, três vezes semanais, de treinamento contra resistência em velocidade. Foram avaliadas a carga (CR), a potência (PT) e a velocidade (VL) no exercício extensão de joelhos (EJ) e no teste motor de levantar-se da cadeira (LC), utilizando o sistema computadorizado Tendo Weightlifting Analyzer (TWA). Foi avaliado também o tempo de execução das tarefas motoras: marcha em velocidade de conforto (MVC) e marcha em velocidade máxima (MVM). Para comparação das variáveis estudadas, aplicou-se o teste t, admitindo-se p=0,05. RESULTADOS: Foi observado no GI para o exercício EJ ganho significativo na capacidade de geração da potência (49,56±13,52w / 66,87±16,27w, p=0,0002). No teste LC, houve aumento significativo na capacidade de geração da potência (370,71±106,26w / 434,52±107,15w, p=0,02185) e da velocidade (0,61±0,14m/s / 0,72±0,14m/s, p=0,00274). Nos testes motores, MVC e MVM, houve redução significativa no tempo de execução (4,56±0,63s / 4,20±0,50s, p=0,01560) e (3,45±0,40s / 3,23±0,34s, p=0,02222), respectivamente. No GC não foi observada melhora significativa em nenhum dos testes aplicados. CONCLUSÃO: O PTCRV contribuiu para melhorar os níveis de potência muscular, além de melhorar o desempenho nas tarefas motoras no grupo estudado.

Concurrent neuromechanical and functional gains following upper-extremity power training post-stroke

BACKGROUND

Repetitive task practice is argued to drive neural plasticity following stroke. However, current evidence reveals that hemiparetic weakness impairs the capacity to perform, and practice, movements appropriately. Here we investigated how power training (i.e., high-intensity, dynamic resistance training) affects recovery of upper-extremity motor function post-stroke. We hypothesized that power training, as a component of upper-extremity rehabilitation, would promote greater functional gains than functional task practice without deleterious consequences.

METHOD

Nineteen chronic hemiparetic individuals were studied using a crossover design. All participants received both functional task practice (FTP) and HYBRID (combined FTP and power training) in random order. Blinded evaluations performed at baseline, following each intervention block and 6-months post-intervention included: Wolf Motor Function Test (WMFT-FAS, Primary Outcome), upper-extremity Fugl-Meyer Motor Assessment, Ashworth Scale, and Functional Independence Measure. Neuromechanical function was evaluated using isometric and dynamic joint torques and concurrent agonist EMG. Biceps stretch reflex responses were evaluated using passive elbow stretches ranging from 60 to 180º/s and determining: EMG onset position threshold, burst duration, burst intensity and passive torque at each speed.

RESULTS

PRIMARY OUTCOME

Improvements in WMFT-FAS were significantly greater following HYBRID vs. FTP (p = .049), regardless of treatment order. These functional improvements were retained 6-months post-intervention (p = .03).

SECONDARY OUTCOMES

A greater proportion of participants achieved minimally important differences (MID) following HYBRID vs. FTP (p = .03). MIDs were retained 6-months post-intervention. Ashworth scores were unchanged (p > .05). Increased maximal isometric joint torque, agonist EMG and peak power were significantly greater following HYBRID vs. FTP (p < .05) and effects were retained 6-months post-intervention (p's < .05). EMG position threshold and burst duration were significantly reduced at fast speeds (≥120º/s) (p's < 0.05) and passive torque was reduced post-washout (p < .05) following HYBRID.

CONCLUSIONS

Functional and neuromechanical gains were greater following HYBRID vs. FPT. Improved stretch reflex modulation and increased neuromuscular activation indicate potent neural adaptations. Importantly, no deleterious consequences, including exacerbation of spasticity or musculoskeletal complaints, were associated with HYBRID. These results contribute to an evolving body of contemporary evidence regarding the efficacy of high-intensity training in neurorehabilitation and the physiological mechanisms that mediate neural recovery.

Eccentric Versus Concentric Resistance Training to Enhance Neuromuscular Activation and Walking Speed Following Stroke

Background. Impaired voluntary neuromuscular activation of agonist muscles is a primary determinant of weakness and motor dysfunction following stroke. Objective. To determine whether eccentric resistance training (ECC) resistance training is superior to concentric resistance training (CON) resistance training to enhance neuromuscular activation, strength, and walking speed after stroke. Methods. A total of 34 adults poststroke participated in a staged intervention comprising (1) either CON-only or ECC-only resistance training of the paretic leg followed by (2) gait training. Changes in voluntary neuromuscular activation and power were assessed for both the trained paretic and untrained nonparetic legs. Self-selected and fast walking speeds were also assessed. Results. In response to resistance training, the ECC group experienced larger improvements in neuromuscular activation of paretic leg muscles, rectus femoris and vastus medialis ( P < .005), and the largest gains in paretic leg power (+74% for ECC contractions, P < .0001). ECC also had greater cross-education of increased power to the untrained nonparetic leg (12%-14%, P = .006). Over the course of gait training, much of the gain in paretic leg activation in the ECC group was lost, such that the net change in agonist activation was comparable between the CON and ECC groups when the full intervention was completed. Nevertheless, improvement in walking speed postintervention was more prevalent in the ECC than CON group. Conclusion. ECC resistance training was more effective for improving bilateral neuromuscular activation, strength, and walking speed following stroke. Future research should assess whether a longer duration ECC training program can provide further benefit.

Exercise and nutritional interventions for improving aging muscle health

Skeletal muscle mass declines with age (i.e., sarcopenia) resulting in muscle weakness and functional limitations. Sarcopenia has been associated with physiological changes in muscle morphology, protein and hormonal kinetics, insulin resistance, inflammation, and oxidative stress. The purpose of this review is to highlight how exercise and nutritional intervention strategies may benefit aging muscle. It is well known that resistance exercise training increases muscle strength and size and evidence also suggests that resistance training can increase mitochondrial content and decrease oxidative stress in older adults. Recent findings suggest that fast-velocity resistance exercise may be an effective intervention for older adults to enhance muscle power and functional capacity. Aerobic exercise training may also benefit aging skeletal muscle by enhancing mitochondrial bioenergetics, improving insulin sensitivity, and/or decreasing oxidative stress. In addition to exercise, creatine monohydrate, milk-based proteins, and essential fatty acids all have biological effects which could enhance some of the physiological adaptations from exercise training in older adults. Additional research is needed to determine whether skeletal muscle adaptations to increased activity in older adults are further enhanced with effective nutritional interventions and whether this is due to enhanced muscle protein synthesis, improved mitochondrial function, and/or a reduced inflammatory response.

Effects of high-speed power training on functional capacity and muscle performance in older women

The purpose of the study was to examine the effects of 12 weeks high-speed power training on isometric contraction (handgrip strength), maximal strength (1RM), muscle power (walking velocity, counter movement jump and ball throwing) and functional tasks of the arm and leg muscles (sit-to-stand and get-up and go). Fifty-six older women were divided into an experimental group and a control group [EG, n=28, 62.5 (5.4) years; CG: n=28, 62.5 (4.3) years]. The EG was submitted to a high-speed power training that consisted of 40% of one repetition maximum (1<RM) to 75% of 1RM); 3 sets 4-12 reps, countermovement jump and medicine ball (1.5 kg) throwing. Over the 12-week training period, the EG significantly increased dynamic and isometric strength performance (57% to 61%), muscle power (range from 14% to 40%) (P<0.05) and function (P<0.05). No significant magnitudes of increase were observed in the CG. These data indicate that high-speed power training is an effective exercise approach leading to large gains in upper and lower extremity muscle performance and function capacity.

Is power training or conventional resistance training better for function in elderly persons? A meta-analysis

OBJECTIVE

to determine the effects of power training with high movement velocity compared with conventional resistance training with low movement velocity for older community-dwelling people.

DESIGN

systematic review of randomised controlled trials.

DATA SOURCES

the Cochrane Central Register of Controlled TRIALS, PubMed (Medline), EMBASE, CINAHL, PEDro and Scholar-Google.

TRIALS

all randomised or quasi-randomised trials investigating power training with high movement velocity versus conventional resistance training with low movement velocity in elderly persons over the age of 60 years. The primary outcomes were measures of functional outcomes; secondary outcomes were balance, gait, strength, power, muscle volume and adverse effects.

RESULTS

eleven trials were identified involving 377 subjects. The pooled effect size for the follow-up values of the functional outcomes was 0.32 in favour of the power training (95% CI 0.06 to 0.57) and 0.38 (95% CI -0.51 to 1.28) for the change value. The pooled effect from three studies for self-reported function was 0.16 in favour of power training (95% CI -0.17 to 0.49).

CONCLUSION

power training is feasible for elderly persons and has a small advantage over strength training for functional outcomes. No firm conclusion can be made for safety.

A pragmatic randomized controlled study of the effectiveness and cost consequences of exercise therapy in hip osteoarthritis

OBJECTIVE

To evaluate the short- and long-term effectiveness of exercise training in relation to pain, function and direct costs to health care systems attributable to hip osteoarthritis.

DESIGN

Prospective, two-year randomized controlled trial.

SETTING

An outpatient primary health care setting.

SUBJECTS

One hundred and twenty men and women aged from 55 to 80, with radiologically diagnosed hip osteoarthritis with associated clinical symptoms.

INTERVENTIONS

The combined exercise and general practitioner (GP) care group received 12 supervised (once per week) exercise sessions at the baseline and four additional booster sessions one year later. Both groups received standard GP care.

MAIN MEASURES

The WOMAC Osteoarthritis Index, physical functioning score of RAND-36 (SF-36), the use and health care system costs of doctor visits and physiotherapy associated with hip osteoarthritis, number of total hip replacements, the use of analgesic and non-steroidal anti-inflammatory drugs (NSAIDs), performance-based outcome scores and body mass index (BMI).

RESULTS

There were no differences between the groups with respect to WOMAC hip pain, physical functioning score of RAND-36, performance-based outcome scores or BMI. The effect of the exercise intervention on WOMAC function was statistically significant at 6 months (mean = -7.5; 95% confidence interval (CI) -13.9 to -1.0; P = 0.02) and 18 months (mean = -7.9; 95% CI -15.3 to -0.4; P = 0.04). There were no statistically significant differences in the total health care system costs between the groups.

CONCLUSION

The mostly home-based exercise training programme provided in this study did not result in reduced hip pain over the two-year follow-up period.

Power training and postmenopausal hormone therapy affect transcriptional control of specific co-regulated gene clusters in skeletal muscle

At the moment, there is no clear molecular explanation for the steeper decline in muscle performance after menopause or the mechanisms of counteractive treatments. The goal of this genome-wide study was to identify the genes and gene clusters through which power training (PT) comprising jumping activities or estrogen containing hormone replacement therapy (HRT) may affect skeletal muscle properties after menopause. We used musculus vastus lateralis samples from early stage postmenopausal (50-57 years old) women participating in a yearlong randomized double-blind placebo-controlled trial with PT and HRT interventions. Using microarray platform with over 24,000 probes, we identified 665 differentially expressed genes. The hierarchical clustering method was used to assort the genes. Additionally, enrichment analysis of gene ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways was carried out to clarify whether assorted gene clusters are enriched with particular functional categories. The analysis revealed transcriptional regulation of 49 GO/KEGG categories. PT upregulated transcription in "response to contraction"-category revealing novel candidate genes for contraction-related regulation of muscle function while HRT upregulated gene expression related to functionality of mitochondria. Moreover, several functional categories tightly related to muscle energy metabolism, development, and function were affected regardless of the treatment. Our results emphasize that during the early stages of the postmenopause, muscle properties are under transcriptional modulation, which both PT and HRT partially counteract leading to preservation of muscle power and potentially reducing the risk for aging-related muscle weakness. More specifically, PT and HRT may function through improving energy metabolism, response to contraction as well as by preserving functionality of the mitochondria.

Dose-response relationship of resistance training in older adults: a meta-analysis

PURPOSE

The purpose of this study was to determine the dose-response relationship of resistance training (RT) to improve strength and function in older adults.

METHODS

A systematic literature search was performed in relevant databases and study reference lists to identify randomized controlled trials. Randomized controlled trials comparing the effects of different doses of strength training in older people (65 yr and older) on strength and functional outcomes were eligible. Two independent reviewers decided on study inclusion, extracted data, and assessed methodological quality. Standardized mean difference (SMD) and 95% confidence intervals (CI) were calculated for relevant outcomes and pooled using a random-effects model.

RESULTS

Twenty-nine trials with a total of 1313 subjects (mean age = 65-81 yr) are summarized in this review. Trials comparing different training intensities show strong effects of progressive resistance training (PRT) on maximal strength in a dose-dependent manner, with high-intensity (HI) PRT being more effective compared with moderate (MI)- and low-intensity (LI) PRT (SMD [HI vs LI] = 0.88, 95% CI = 0.21-1.55; SMD [HI vs MI] = 0.62, 95% CI = 0.22-1.03). PRT was also successful for improving functional outcomes, but gains were independent of training intensity. Power training (PT) was more effective for improving muscle power (SMD [PT vs PRT] = 1.66, 95% CI = 0.08-3.24) and functional outcomes than PRT. There was only little information available on training volume and frequency.

DISCUSSION

Higher training intensities are superior to lower intensities for improving maximal strength but not necessarily for functional performance of older adults. PT has shown to be a particularly effective method for enhancing muscle power and functional performance. More research is necessary to identify the effect of different training volumes and frequencies and the dose-response relationship for very old and frail populations.

Resistance Exercise Did Not Alter Intramuscular Adipose Tissue but Reduced Retinol-binding Protein-4 Concentration in Individuals with Type 2 Diabetes Mellitus

Lipid accumulation in muscle is associated with diminished insulin sensitivity. It was hypothesized that resistance exercise decreases muscular adipose tissue and reduces the level of retinol-binding protein-4 (RBP4), which is linked to adipose tissue and insulin sensitivity in diabetics. Forty-four women with type 2 diabetes were randomly assigned to three groups for a period of 12 weeks: control (asked to maintain a sedentary lifestyle); resistance exercise (elastic band exercise at moderate intensity five times per week); and aerobic exercise (walking for 60 min at moderate intensity five times per week). Subcutaneous (SCAT), subfascial (SFAT) and intramuscular (IMAT) adipose tissues at mid-thigh level were assessed using computed tomography, and RBP4 level and insulin sensitivity (fractional disappearance rate of insulin, kITT) were assessed before and after intervention. Changes in SCAT, SFAT, IMAT, RBP4 and kITT were similar among the three groups. Within-group analysis revealed that body mass index and waist circumference decreased significantly in both exercise groups, but RBP4 decreased significantly only with resistance exercise. Resistance exercise did not alter muscular adipose tissue or improve insulin sensitivity.

Gait Disorders and Falls

Since approximately 30% of persons over the age of 65 fall each year, prevention of falls is a very important topic. Gait disorders and diminished ability to walk safely are associated with an increased risk of falling. In older adults, falls commonly lead to injuries, institutionalization, and early death. The resultant decline in activities of daily living further contributes to loss of mobility and independence. Gait analysis using the dual-task paradigm (e.g., walking and carrying a cup of tea) offers a sensible tool for detecting older persons prone to falling. Changes in gait patterns due to simultaneously performing a secondary attention-demanding task are interpreted as interference by competing demands for attentional resources in gait control. Exercise interventions such as Jaques-Dalcroze eurhythmics address these attentional properties and aim to decrease such interference. To fully stress physical capacities in older adults, not only does automaticity of walking have to be trained, but also simultaneous performance of additional tasks. Exercise interventions for fall prevention should focus on developing basic skeletal muscle strength as a prerequisite to training gait automaticity in dual or multiple task situations. Recommendations for further research center on new approaches to combine exercises with additional tasks to improve gait and functionality in older adults.

Potential of creatine supplementation for improving aging bone health

Aging subsequently results in bone and muscle loss which has a negative effect on strength, agility, and balance leading to increased risks of falls, injuries, and fractures. Resistance training is an effective strategy for maintaining bone mass, possibly by increasing activity of cells involved in bone formation and reducing activity of cells involved in bone resorption. However, bone loss is still evident in older adults who have maintained resistance training for most of their life, suggesting that other factors such as nutrition may be involved in the aging bone process. Emerging evidence suggests that creatine supplementation, with and without resistance training, has the potential to influence bone biology. However, research investigating the longer-term effects of creatine supplementation and resistance training on aging bone is limited.

[Aging and physical activity data on which to base recommendations for exercise in older adults]

An abundance of epidemiological research confirms the benefits of physical activity in reducing risk of various age-related morbidities and all-cause mortality. Analysis of the literature focusing on key exercise variables (e.g., intensity, type, and volume) suggests that the requisite beneficial amount of activity is that which engenders improved cardiorespiratory fitness, strength, power, and, indirectly, balance. Age-related declines in these components are such that physical limitations impinge on functional activities of daily living. However, an exercise programme can minimize declines, thus preventing older adults (age 65+ years) from crossing functional thresholds of inability. Cross-sectional and longitudinal data demonstrate that cardiorespiratory fitness is associated with functional capacity and independence; strength and, importantly, power are related to performance and activities of daily living; and balance-mobility in combination with power are important factors in preventing falls. Exercise interventions have documented that older adults can adapt physiologically to exercise training, with gains in functional capacities. The few studies that have explored minimal or optimal activity requirements suggest that a threshold (intensity) within the moderately vigorous domain is needed to achieve and preserve related health benefits. Thus, physical activity and (or) exercise prescriptions should emphasize activities of the specificity and type to improve components related to the maintenance of functional capacity and independence; these will also delay morbidity and mortality. An appropriate recommendation for older adults includes moderately vigorous cardiorespiratory activities (e.g., brisk walking), strength and (or) power training for maintenance of muscle mass and specific muscle-group performance, as well as "balance-mobility practice" and flexibility (stretching) exercise as needed.

THE EFFECT OF PHYSICAL TRAINING ON THE LOCOMOTOR APPARATUS IN ELDERLY PEOPLE

Physiological changes taking place on the locomotive apparatus as a result of aging, such as muscular mass loss, body balance loss, reduced bone mass and osteoarthrosis cause limitations to the daily activities of elderly people, compromising their quality of life and making them weaker and dependent. Aged people who regularly practice physical activities have a higher level of functional independence and a better quality of life than the sedentary ones. This article addresses the key physiological changes with aging and provides a review of current literature about the effects of physical exercises on the locomotive apparatus of elderly individuals, specifying the best ways to prescribe physical exercises to this age group.

Explosive heavy-resistance training in old and very old adults: changes in rapid muscle force, strength and power

Age-related decline in muscle power predicts falls, motor impairments and disability. Recent guidelines suggested that training programs should be tailored to maximize muscle power. This study investigated the effects of 12 weeks of explosive-type heavy-resistance training (75-80% of 1 repetition maximum) in old (60-65 years, TG60) and very old (80-89 years, TG80) community-dwelling women. Training was performed with maximal intentional acceleration of the training load during the concentric movement phase. Maximal isometric voluntary muscle strength (MVC), rapid force capacity, assessed as rate of force development (RFD), and impulse, maximal muscle power during a countermovement jump (CMJ) and during unilateral leg extension task (LEP) were evaluated. RFD, impulse and MVC increased by 51%, 42% and 28% in TG80, and by 21%, 18% and 18% in TG60, respectively. CMJ jump height increased by 18% and 10% in TG80 and TG60, respectively, while jump peak power increased in TG60 (5%). Finally, LEP increased 28% in TG80 and 12% in TG60. These findings demonstrate that explosive-type heavy-resistance training seems to be safe and well tolerated in healthy women even in the eighth decade of life and elicits adaptive neuromuscular changes in selected physiological variables that are commonly associated with the risk of falls and disability in aged individuals.

Ageing and physical activity: evidence to develop exercise recommendations for older adultsThis article is part of a supplement entitled Advancing physical activity measurement and guidelines in Canada: a scientific review and evidence-based foundation for the future of Canadian physical activity guidelines co-published by Applied Physiology, Nutrition, and Metabolism and the Canadian Journal of Public Health. It may be cited as Appl. Physiol. Nutr. Metab. 32(Suppl. 2E) or as Can. J. Public Health 98(Suppl. 2)

An abundance of epidemiological research confirms the benefits of physical activity in reducing risk of various age-related morbidities and all-cause mortality. Analysis of the literature focusing on key exercise variables (e.g., intensity, type, and volume) suggests that the requisite beneficial amount of activity is that which engenders improved cardiorespiratory fitness, strength, power, and, indirectly, balance. Age-related declines in these components are such that physical limitations impinge on functional activities of daily living. However, an exercise programme can minimize declines, thus preventing older adults (age 65+ years) from crossing functional thresholds of inability. Cross-sectional and longitudinal data demonstrate that cardiorespiratory fitness is associated with functional capacity and independence; strength and, importantly, power are related to performance and activities of daily living; and balance-mobility in combination with power are important factors in preventing falls. Exercise interventions have documented that older adults can adapt physiologically to exercise training, with gains in functional capacities. The few studies that have explored minimal or optimal activity requirements suggest that a threshold (intensity) within the moderately vigorous domain is needed to achieve and preserve related health benefits. Thus, physical activity and (or) exercise prescriptions should emphasize activities of the specificity and type to improve components related to the maintenance of functional capacity and independence; these will also delay morbidity and mortality. An appropriate recommendation for older adults includes moderately vigorous cardiorespiratory activities (e.g., brisk walking), strength and (or) power training for maintenance of muscle mass and specific muscle-group performance, as well as “balance-mobility practice” and flexibility (stretching) exercise as needed.