Longitudinal study of determinants of dependence in an elderly population

HIIT at Home: Enhancing Cardiorespiratory Fitness in Older Adults-A Randomized Controlled Trial

BACKGROUND

This study aimed to investigate the effectiveness of a 6-month home-based high-intensity interval training (HIIT) intervention to improve peak oxygen consumption (V̇O2peak) and lactate threshold (LT) in older adults.

METHODS

Two hundred thirty-three healthy older adults (60-84 years; 54% females) were randomly assigned to either 6-month, thrice-weekly home-based HIIT (once-weekly circuit training and twice-weekly interval training) or a passive control group. Exercise sessions were monitored using a Polar watch and a logbook for objective and subjective data, respectively, and guided by a personal coach. The outcomes were assessed using a modified Balke protocol combining V̇O2peak and LT measures. General linear regression models assessed between-group differences in change and within-group changes for each outcome.

RESULTS

There was a significant between-group difference in the pre-to-post change in V̇O2peak (difference: 1.8 [1.2; 2.3] mL/kg/min; exercise: +1.4 [1.0; 1.7] mL/kg/min [~5%]; control: -0.4 [-0.8; -0.0] mL/kg/min [approximately -1.5%]; effect size [ES]: 0.35). Compared with controls, the exercise group had lower blood lactate concentration (-0.7 [-0.9; -0.4] mmol/L, ES: 0.61), % of peak heart rate (-4.4 [-5.7; -3.0], ES: 0.64), and % of V̇O2peak (-4.5 [-6.1; -2.9], ES: 0.60) at the intensity corresponding to preintervention LT and achieved a higher treadmill stage (% incline) at LT (0.6 [0.3; 0.8]; ES: 0.47), following the intervention.

CONCLUSION

This study highlights the effectiveness of a home-based HIIT intervention as an accessible and equipment-minimal strategy to induce clinically meaningful improvements in cardiorespiratory fitness in older adults. Over 6 months, the exercise group showed larger improvements in all outcomes compared with the control group. Notably, the LT outcome exhibited a more pronounced magnitude of change than V̇O2peak.

Burn size and environmental conditions modify thermoregulatory responses to exercise in burn survivors

This project tested the hypothesis that burn survivors can perform mild/moderate-intensity exercise in temperate and hot environments without excessive elevations in core body temperature. Burn survivors with low (23 ± 5%TBSA; N = 11), moderate (40 ± 5%TBSA; N = 9), and high (60 ± 8%TBSA; N = 9) burn injuries performed 60 minutes of cycle ergometry exercise (72 ± 15 watts) in a 25°C and 23% relative humidity environment (ie, temperate) and in a 40°C and 21% relative humidity environment (ie, hot). Absolute gastrointestinal temperatures (TGI) and changes in TGI (ΔTGI) were obtained. Participants with an absolute TGI of >38.5°C and/or a ΔTGI of >1.5°C were categorized as being at risk for hyperthermia. For the temperate environment, exercise increased ΔTGI in all groups (low: 0.72 ± 0.21°C, moderate: 0.42 ± 0.22°C, and high: 0.77 ± 0.25°C; all P < .01 from pre-exercise baselines), resulting in similar absolute end-exercise TGI values (P = .19). Importantly, no participant was categorized as being at risk for hyperthermia, based upon the aforementioned criteria. For the hot environment, ΔTGI at the end of the exercise bout was greater for the high group when compared to the low group (P = .049). Notably, 33% of the moderate cohort and 56% of the high cohort reached or exceeded a core temperature of 38.5°C, while none in the low cohort exceeded this threshold. These data suggest that individuals with a substantial %TBSA burned can perform mild/moderate intensity exercise for 60 minutes in temperate environmental conditions without risk of excessive elevations in TGI. Conversely, the risk of excessive elevations in TGI during mild/moderate intensity exercise in a hot environment increases with the %TBSA burned.

Relative importance of inflammation and cardiorespiratory fitness for all-cause mortality risk in persons with rheumatoid arthritis: the population-based Trøndelag Health Study

OBJECTIVE

Inflammation and reduced cardiorespiratory fitness (CRF) are associated with increased mortality rates in rheumatoid arthritis (RA). We aimed at directly comparing the relative importance of inflammation and reduced CRF as mediators of all-cause mortality in persons with RA compared with controls, quantifying direct and indirect (mediated) effects.

METHODS

Persons with (n=223, cases) and without (n=31 684, controls) RA from the third survey of the Trøndelag Health Study (HUNT3, 2006-2008) were included. Inflammation was quantified using C reactive protein (CRP) and estimated CRF (eCRF) was calculated using published formulae. All-cause mortality was found by linkage to the Norwegian Cause of Death Registry, with follow-up from inclusion in HUNT3 until death or 31 December 2018. Data were analysed using standardised equation modelling, permitting complex correlations among variables.

RESULTS

Persons with RA had increased all-cause mortality rates (24.1% vs 9.9%, p<0.001). Both eCRF (p<0.001) and CRP ≥3 mg/L (p<0.001) were mediators of this excess mortality, rendering the direct effect of RA non-significant (p=0.19). The indirect effect of RA mediated by eCRF (standardised coefficient 0.006) was approximately three times higher than the indirect effect mediated by CRP (standardised coefficient 0.002) in a model adjusted for other mortality risk factors.

CONCLUSION

Even with CRP concentrations <3 mg/L in all patients with RA, excess mortality mediated by low CRF would still play an important role. Improved inflammation control in RA does not necessarily lead to better CRF. Therefore, our study strongly supports recommendations for development and implementation of exercise programmes aimed at improving CRF in persons with RA.

Cardiac remodeling in well-healed burn survivors after 6 months of unsupervised progressive exercise training

Aerobic exercise is important in the rehabilitation of individuals with prior burn injuries, but no studies have examined whether adult burn survivors demonstrate cardiac remodeling to long-term aerobic exercise training. In this study, we tested the hypothesis that 6 months of progressive exercise training improves cardiac magnetic resonance imaging-based measures of cardiac structure and function in well-healed burn survivors. Secondary analyses explored relations between burn surface area and changes in cardiac structure in the cohort of burn survivors. V̇o2peak assessments and cardiac magnetic resonance imaging were performed at baseline and following 6 months of progressive exercise training from 19 well-healed burn survivors and 10 nonburned control participants. V̇o2peak increased following 6 months of training in both groups (Control: Δ5.5 ± 5.8 mL/kg/min; Burn Survivors: Δ3.2 ± 3.6 mL/kg/min, main effect of training, P < 0.001). Left ventricle (LV) mass (Control: Δ1.7 ± 3.1 g/m2; Burn survivors: Δ1.8 ± 2.7 g/m2), stroke volume (Control: Δ5.8 ± 5.2 mL/m2; Burn Survivors: Δ2.8 ± 4.2 mL/m2), and ejection fraction (Control: Δ2.4 ± 4.0%; Burn Survivors: Δ2.2 ± 4.3%) similarly increased following 6 months of exercise training in both cohorts (main effect of training P < 0.05 for all indexes). LV end-diastolic volume increased in the control group (Δ6.5 ± 4.5 mL/m2) but not in the cohort of burn survivors (Δ1.9 ± 2.7 mL/m2, interaction, P = 0.040). Multiple linear regression analyses revealed that burn surface area had little to no effect on changes in ventricular mass or end-diastolic volumes in response to exercise training. Our findings provide initial evidence of physiological cardiac remodeling, which is not impacted by burn size, in response to exercise training in individuals with well-healed burn injuries.NEW & NOTEWORTHY Aerobic exercise is important in the rehabilitation of individuals with prior burn injuries, but no studies have examined whether adult burn survivors demonstrate cardiac remodeling to long-term aerobic exercise training. In this study, we tested the hypothesis that 6 months of progressive exercise training would improve cardiac magnetic resonance imaging-based measures of cardiac structure and function in well-healed burn survivors. Our findings highlight the ability of exercise training to modify cardiac structure and function in well-healed burn survivors and nonburned sedentary controls alike.

Effects of an individualized and progressive multicomponent exercise program on blood pressure, cardiorespiratory fitness, and body composition in long-term care residents: Randomized controlled trial

This study analyzed the effects of an individualized and progressive multicomponent exercise program on blood pressure, cardiorespiratory fitness, and body composition in long-term care residents. This was a single-blind, multicenter, randomized controlled trial performed in 10 long-term care settings and involved 112 participants. Participants were randomly assigned to a control group or an intervention group. The control group participated in routine activities; the intervention group participated in a six-month individualized and progressive multicomponent exercise program focused on strength, balance, and walking recommendations. The intervention group maintained peak VO₂, oxygen saturation, and resting heart rate, while the control group showed a significant decrease in peak VO₂ and oxygen saturation and an increase in resting heart rate throughout the six-month period. Individualized and progressive multicomponent exercise programs comprising strength, balance, and walking recommendations appear to be effective in preventing cardiorespiratory fitness decline in older adults living in long-term care settings.

Edward F. Adolph Distinguished Lecture. It's more than skin deep: thermoregulatory and cardiovascular consequences of severe burn injuries in humans

Each year, within the United States, tens of thousands of individuals are hospitalized for burn-related injuries. The treatment of deep burns often involves skin grafts to accelerate healing and reduce the risk of infection. The grafting procedure results in a physical disruption between the injured and subsequently debrided host site and the skin graft placed on top of that site. Both neural and vascular connections must occur between the host site and the graft for neural modulation of skin blood flow to take place. Furthermore, evaporative cooling from such burn injured areas is effectively absent, leading to greatly impaired thermoregulatory responses in individuals with large portions of their body surface area burned. Hospitalization following a burn injury can last weeks to months, with cardiovascular and metabolic consequences of such injuries having the potential to adversely affect the burn survivor for years postdischarge. With that background, the objectives of this article are to discuss 1) our current understanding of the physiology and associated consequences of skin grafting, 2) the effects of skin grafts on efferent thermoregulatory responses and the associated consequences pertaining to whole body thermoregulation, 3) approaches that may reduce the risk of excessive hyperthermia in burn survivors, 4) the long-term cardiovascular consequences of burn injuries, and 5) the extent to which burn survivors can "normalize" otherwise compromised cardiovascular responses. Our primary objective is to guide the reader toward an understanding that severe burn injuries result in significant physiological consequences that can persist for years after the injury.

Effect of 5 years of exercise training on the cardiovascular risk profile of older adults: the Generation 100 randomized trial

AIMS

The aim of this study was to compare the effects of 5 years of supervised exercise training (ExComb), and the differential effects of subgroups of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT), with control on the cardiovascular risk profile in older adults.

METHODS AND RESULTS

Older adults aged 70-77 years from Trondheim, Norway (n = 1567, 50% women), able to safely perform exercise training were randomized to 5 years of two weekly sessions of HIIT [∼90% of peak heart rate (HR), n = 400] or MICT (∼70% of peak HR, n = 387), together forming ExComb (n = 787), or control (instructed to follow physical activity recommendations, n = 780). The main outcome was a continuous cardiovascular risk score (CCR), individual cardiovascular risk factors, and peak oxygen uptake (VO2peak). CCR was not significantly lower [-0.19, 99% confidence interval (CI) -0.46 to 0.07] and VO2peak was not significantly higher (0.39 mL/kg/min, 99% CI -0.22 to 1.00) for ExComb vs. control. HIIT showed higher VO2peak (0.76 mL/kg/min, 99% CI 0.02-1.51), but not lower CCR (-0.32, 99% CI -0.64 to 0.01) vs. control. MICT did not show significant differences compared to control or HIIT. Individual risk factors mostly did not show significant between-group differences, with some exceptions for HIIT being better than control. There was no significant effect modification by sex. The number of cardiovascular events was similar across groups. The healthy and fit study sample, and contamination and cross-over between intervention groups, challenged the possibility of detecting between-group differences.

CONCLUSIONS

Five years of supervised exercise training in older adults had little effect on cardiovascular risk profile and did not reduce cardiovascular events.

REGISTRATION

ClinicalTrials.gov: NCT01666340.

Cardiopulmonary exercise performance and factors associated with aerobic capacity in neuromuscular diseases

INTRODUCTION/AIMS

Aerobic deconditioning, due to lower levels of physical activity, could impact independence for people with neuromuscular conditions. We report the maximal cardiopulmonary response in a cohort of people with Charcot Marie Tooth disease type 1A (CMT 1A) and inclusion body myositis (IBM). We also explored potential predictors of aerobic capacity with measures of physical impairment and functional performance.

METHODS

Participants underwent maximal cardiopulmonary exercise testing (CPET) using a semi-recumbent cycle ergometer. Data were analyzed to determine the peak O₂ consumption (VO₂ peak), anaerobic threshold (AT), maximum heart rate (MHR), ventilatory equivalent for CO₂ slope (V_E /VCO₂ ), and respiratory exchange ratio (RER). Impairment, functional and patient reported measures were also recorded. Predicted CPET variables were calculated based on published normative data for age, gender, and weight.

RESULTS

Twenty-two people with CMT and 17 people with IBM were recruited. Both groups showed significantly lower VO₂ peak, MHR, AT, and V_E /VCO₂ . The CMT group overall performed better than the IBM group, with significantly higher VO₂ peak, MHR, and AT, but lower V_E /VCO_2. Linear regression analysis demonstrated that VO₂ peak was related to body fat percentage and 6-min walk distance for both groups, and steps per day for the IBM group.

DISCUSSION

Lower than predicted CPET variables were observed that were not explained by cardiopulmonary limitations or reduced effort, implicating peripheral factors in limiting the cycling task. Regression analysis implied prediction of VO2 peak by body fat percentage and 6-min walk distance. Six-minute walk distance could be a potential proxy measure of cardiopulmonary fitness.

Comparison of constant load exercise intensity for verification of maximal oxygen uptake following a graded exercise test in older adults

Maximal oxygen uptake (VO2 max) declines with advancing age and is a predictor of morbidity and mortality risk. The purpose here was to assess the utility of constant load tests performed either above or below peak work rate obtained from a graded exercise test for verification of VO2 max in older adults. Twenty-two healthy older adults (9M, 13F, 67 ± 6 years, BMI: 26.3 ± 5.1 kg·m-2 ) participated in the study. Participants were asked to complete two experimental trials in a randomized, counterbalanced cross-over design. Both trials (cycle ergometer) consisted of (1) an identical graded exercise test (ramp) and (2) a constant load test at either 85% (CL85; n = 22) or 110% (CL110; n = 20) of the peak work rate achieved during the associated ramp (performed 10-min post ramp). No significant differences were observed for peak VO2 (L·min-1 ) between CL85 (1.86 ± 0.72; p = 0.679) or CL110 (1.79 ± 0.73; p = 0.200) and the associated ramp (Ramp85, 1.85 ± 0.73; Ramp110, 1.85 ± 0.57). Using the study participant's mean coefficient of variation in peak VO2 between the two identical ramp tests (2.9%) to compare individual differences between constant load tests and the associated ramp revealed 19/22 (86%) of participants achieved a peak VO2 during CL85 that was similar or higher versus the ramp, while only 13/20 (65%) of participants achieved a peak VO2 during CL110 that was similar or higher versus the ramp. These data indicate that if a verification of VO2 max is warranted when testing older adults, a constant load effort at 85% of ramp peak power may be more likely to verify VO2 max as compared to an effort at 110% of ramp peak power.

Sympathetic vasoconstriction in skeletal muscle: Modulatory effects of aging, exercise training, and sex

The sympathetic nervous system (SNS) is a critically important regulator of the cardiovascular system. The SNS controls cardiac output and its distribution, as well as peripheral vascular resistance and blood pressure at rest and during exercise. Aging is associated with increased blood pressure and decreased skeletal muscle blood flow at rest and in response to exercise. The mechanisms responsible for the blunted skeletal muscle blood flow response to dynamic exercise with aging have not been fully elucidated; however, increased muscle sympathetic nerve activity (MSNA), elevated vascular resistance and a decline in endothelium-dependent vasodilation are commonly reported in older adults. In contrast to aging, exercise training has been shown to reduce blood pressure and enhance skeletal muscle vascular function. Exercise training has been shown to enhance nitric oxide-dependent vascular function and may improve the vasodilatory capacity of the skeletal muscle vasculature; however, surprisingly little is known about the effect of exercise training on the neural control of circulation. The control of blood pressure and skeletal muscle blood flow also differs between males and females. Blood pressure and MSNA appear to be lower in young females compared to males. However, females experience a larger increase in MSNA with aging compared to males. The mechanism(s) for the altered SNS control of vascular function in females remain to be determined. Novelty: • This review will summarize our current understanding of the effects of aging, exercise training and sex on sympathetic vasoconstriction at rest and during exercise. • Areas where additional research is needed are also identified.

Carbohydrate mouth rinsing does not affect 6-min walk test performance and blood glucose responses in older adults

PURPOSE

Carbohydrate (CHO) mouth rinsing (MR) prior to exercise has been shown to elicit enhanced performance and energy availability in some studies. Previous literature has concentrated on examining CHO MR strategies for improving aerobic endurance performance in younger athletic adults. Knowledge of the impact of CHO MR on functional performance in older adults is scarce. The purpose of this investigation was to determine if CHO MR would improve 6-min walk test (6MWT) performance, perceived exertion, and blood glucose responses in older adults.

METHOD

Thirty-three individuals (16 males, 17 females), age ≥ 70 years performed two 6MWT trials, one of which utilized a 6.4% maltodextrin CHO MR and one of which utilized a placebo MR. Participants held the MR in their mouth for 20 s prior to the 6MWT, and trials occurred in a counterbalanced fashion. Total distance walked and rating of perceived exertion (RPE) were recorded upon completion of each 6MWT. Heart rate (HR), peripheral blood oxygen saturation (SpO₂), systolic and diastolic blood pressures (BP), blood glucose, and blood lactate were measured before and after each 6MWT.

RESULT

CHO MR did not alter the response of any study parameter compared to the placebo MR (p = 0.13-0.94). HR, systolic BP, and blood lactate increased and SpO₂ decreased across time (p < 0.01).

CONCLUSION

A 6.4% maltodextrin CHO MR did not alter total distance walked, perceived exertion, or other physiological responses elicited by the 6MWT in older adults.

Preserved skeletal muscle oxidative capacity in older adults despite decreased cardiorespiratory fitness with ageing

KEY POINTS

Healthy older adults exhibit lower cardiorespiratory fitness ( V ̇ O 2 peak ) than young in the absence of any age-related difference in skeletal muscle mitochondrial capacity, suggesting central haemodynamics plays a larger role in age-related declines in V ̇ O 2 peak . Total physical activity did not differ by age, but moderate-to-vigorous physical activity was lower in older compared to young adults. Moderate-to-vigorous physical activity is associated with V ̇ O 2 peak and muscle oxidative capacity, but physical inactivity cannot entirely explain the age-related reduction in V ̇ O 2 peak .

ABSTRACT

Declining fitness ( V ̇ O 2 peak ) is a hallmark of ageing and believed to arise from decreased oxygen delivery and reduced muscle oxidative capacity. Physical activity is a modifiable lifestyle factor that is critical when evaluating the effects of age on parameters of fitness and energy metabolism. The objective was to evaluate the effects of age and sex on V ̇ O 2 peak , muscle mitochondrial physiology, and physical activity in young and older adults. An additional objective was to assess the contribution of skeletal muscle oxidative capacity to age-related reductions in V ̇ O 2 peak and determine if age-related variation in V ̇ O 2 peak and muscle oxidative capacity could be explained on the basis of physical activity levels. In 23 young and 52 older men and women measurements were made of V ̇ O 2 peak , mitochondrial physiology in permeabilized muscle fibres, and free-living physical activity by accelerometry. Regression analyses were used to evaluate associations between age and V ̇ O 2 peak , mitochondrial function, and physical activity. Significant age-related reductions were observed for V ̇ O 2 peak (P < 0.001), but not muscle mitochondrial capacity. Total daily step counts did not decrease with age, but older adults showed lower moderate-to-vigorous physical activity, which was associated with V ̇ O 2 peak (R²  = 0.323, P < 0.001) and muscle oxidative capacity (R²  = 0.086, P = 0.011). After adjusting for sex and physical activity, age was negatively associated with V ̇ O 2 peak but not muscle oxidative capacity. Healthy older adults exhibit lower V ̇ O 2 peak but preserved mitochondrial capacity compared to young. Physical activity, particularly moderate-to-vigorous, is a key factor in observed age-related changes in fitness and muscle oxidative capacity, but cannot entirely explain the age-related reduction in V ̇ O 2 peak .

Using Accelerometer Data to Identify Movement Patterns in an Older Adult: Innovative Strategy for Physical Activity Promotion

Evidence suggests a physically active lifestyle increases proportion of life lived free of disability. Unfortunately, physical activity participation in older adults is low, suggesting innovative strategies are needed. This case-report (1) examined daily activity routines from accelerometer data; and (2) utilized the movement patterns to "infuse" physical activity within the participant's normal routine.

CASE-REPORT

A 60 year old wore an Actigraph GT3X+ accelerometer, on 2 separate days and weeks. Movement patterns, from "raw" accelerometer data, were presented to the participant to identify areas of high and low activity, with suggestions how to increase overall activity. Results indicated activity patterns were reproducible. Physical activity infusions increased movement counts by 34%, and moderate-vigorous physical activity (MVPA) by ~82minutes.

DISCUSSION

Examination of "raw" accelerometer data identified distinct movement routines. Understanding these routines allowed for health provider/participant interaction that led to physical activity "infusions" which contributed to a large increase in MVPA, without major alterations to the individual's day.

The effect of age on mechanisms of exercise tolerance: Reduced arteriovenous oxygen difference causes lower oxygen consumption in older people

OBJECTIVE

To assess the effect of age on mechanisms of exercise tolerance.

METHODS

Prospective observational study recruited 71 healthy individuals divided into two groups according to their age i.e. younger (≤40 years of age, N = 43); and older (≥55 years of age, N = 28). All participants underwent maximal graded cardiopulmonary exercise stress testing using cycle ergometer with simultaneous non-invasive gas-exchange and central haemodynamic measurements. Using the Fick equation, arteriovenous O₂ difference was calculated as the ratio between measured O₂ consumption and cardiac output.

RESULTS

The mean age of younger and older participants was 26.0 ± 5.7 years, and 65.1 ± 6.6 years respectively. Peak O₂ consumption was significantly lower in older compared to the younger age group (18.8 ± 5.2 vs 34.4 ± 9.8 mL/kg/min, p < 0.01). Peak exercise cardiac output and cardiac index were not significantly different between the younger and older age groups (22.7 ± 5.0 vs 22.1 ± 3.9 L/min, p = 0.59; and 12.4 ± 2.9 vs 11.8 ± 1.9 L/min/m², p = 0.29). Despite demonstrating significantly lower peak heart rate by 33 beats/min (129 ± 18.3 vs 162 ± 19.9, p < 0.01), older participants demonstrated significantly higher stroke volume and stroke volume index compared to the younger age group (173 ± 41.5 vs 142 ± 34.9 mL/min, p < 0.01; and 92.1 ± 18.1 vs 78.3 ± 19.5 mL/m², p < 0.01). Arteriovenous O₂ difference was significantly lower in older compared to younger age group participants (9.01 ± 3.0 vs 15.8 ± 4.3 mlO₂/100 mL blood, p < 0.01).

CONCLUSION

Ability of skeletal muscles to extract delivered oxygen represented by reduced arteriovenous O₂ difference at peak exercise appears to be the key determinant of exercise tolerance in healthy older individuals.

Sex differences in the contribution of different physiological systems to physical function in older adults

Having the physical function to undertake activities of daily living (ADLs) is essential in order to maintain independence. The aim of this study is to investigate factors associated with physical function in older adults and determine if these associations differ in men versus women. In total, 726 participants (57% men; 73±7 years old) from a population-based cohort, the Southall and Brent Revisited (SABRE) study, completed questionnaires permitting a physical function score (PFS) to be calculated. Detailed phenotyping was performed including cardiovascular (echocardiography and macrovascular and microvascular functions), skeletal muscle (grip strength and oxidative capacity) and lung (pulmonary) function measurements. In a sub-group, maximal aerobic capacity was estimated from a sub-maximal exercise test. In women versus men, the association between grip strength and PFS was nearly 3 times stronger, and the association between microvascular dysfunction and PFS was over 5 times stronger (standardized β-coefficient (95% CI) 0.34 (0.22, 0.45) versus 0.11 (0.01,0.22) and -0.27 (-0.37, -0.17) versus -0.05 (-0.14, 0.04), respectively). In men, the association between cardiorespiratory fitness and PFS was 3 times greater than that in women (standardized β-coefficient (95% CI) 0.33 (0.22, 0.45) versus 0.10 (-0.04, 0.25). Cardiovascular, skeletal muscle and pulmonary factors all contribute to self-reported physical function, but the relative pattern of contribution differs by sex. Grip strength and microvascular function are most strongly associated with physical function in women while cardiorespiratory fitness is most strongly associated with physical function in men. This is relevant to the design of effective interventions that target maintenance of physical function in old age.

Muscle mass and aerobic capacity in older women: Impact of regular exercise at middle age

BACKGROUND

The impact of regular exercise habits at middle-age on muscle mass and function at old age remains inconclusive. While regular exercise likely represents a primary source of health-enhancing physical activity (PA), the physical demand of occupation needs to be considered. Additionally, PA level at old age should be taken into account in order to elucidate true associations between past exercise behaviors and muscle mass and function at old age. Therefore, the aim of the study was to examine the impact of regular exercise habits during middle age years on muscle mass and physical function at old age, while considering occupation and objectively assessed PA level at old age.

METHODS

Self-reported leisure-time PA during middle age years [35-65 years] and present accelerometer-derived PA level were assessed in a population of community-dwelling older women (65-70 years; n = 112). Participants who accumulated at least 600 MET-min of PA per week during middle age years were classified as physically active. Skeletal muscle mass index (SMI), aerobic fitness and maximal isometric arm and leg strength were determined. Analyses of differences in muscle mass and physical function between physically active and inactive at middle age were adjusted by present PA, adiposity level, and the physical demand of former occupation (sedentary vs manual).

RESULTS

Participants accumulating at least 600 MET-min of exercise-related activities during middle-age years had higher aerobic fitness (P < 0.01) and SMI (P < 0.05) at old age compared to their less active peers. Notably, these beneficial impacts were driven by exercise habits during late middle-age period [50 to 65 years], and remained significant after further adjustment by the physical demand of former occupation and present PA behavior at old age. Finally, middle-age engagement in exercise-related activities had no influence on maximal arm and leg isometric strength at old age.

CONCLUSION

Our findings highlight the importance of engaging in regular PA of at least moderate intensity during middle age years in order to promote benefits at the level of muscle mass and aerobic fitness. This clearly supports the potential of PA in delaying aerobic capacity impairment and the occurrence of clinically manifest sarcopenia at old age.

The effects of Age, Organized Physical Activity and Sedentarism on Fitness in Older Adults: An 8-Year Longitudinal Study

The aims of the present study were (1) to describe the changes in physical fitness during an 8 year follow-up in a large sample of Spanish adults aged 65 or over that are initially engaged in organized physical activity (OPA), (2) to compare fitness changes according to different age groups (65 to 69 vs. 70 to 74 vs. ≥75 years-old), (3) to evaluate the independent and combined effects of changes in OPA engagement and sitting time (ST) on physical fitness. A total of 642 (147 males) non-institutionalized over 65 years-old participants completed the EXERNET battery fitness tests and completed a validated questionnaire from which information regarding OPA and ST were collected. All participants completed evaluations in 2008–2009 and in 2016–2017. An impairment of fitness-related variables happens after 65 years of age in both males and females, with the older participants (≥75), showing the largest decreases. Males who continued performing OPA demonstrated lower decreases in balance, leg flexibility and agility when compared to those who stopped performing OPA during the follow-up. Females who continued performing OPA demonstrated lower decreases of all variables except for balance when compared to those who stopped performing OPA during the follow-up.

The effect of lifelong endurance exercise on cardiovascular structure and exercise function in women

KEY POINTS

The beneficial effects of sustained or lifelong (>25 years) endurance exercise on cardiovascular structure and exercise function have been largely established in men. The current findings indicate that committed (≥4 weekly exercise sessions) lifelong exercise results in substantial benefits in exercise capacity ( V ̇ O 2 max ), cardiovascular function at submaximal and maximal exercise, left ventricular mass and compliance, and blood volume compared to similarly aged or even younger (middle-age) untrained women. Endurance exercise training should be considered a key strategy to prevent cardiovascular disease with ageing in women as well as men.

ABSTRACT

This study was a retrospective, cross-sectional analysis of exercise performance and left ventricular (LV) morphology in 70 women to examine whether women who have performed regular, lifelong endurance exercise acquire the same beneficial adaptations in cardiovascular structure and function and exercise performance that have been reported previously in men. Three groups of women were examined: (1) 35 older (>60 years) untrained women (older untrained, OU), (2) 13 older women who had consistently performed four or more endurance exercise sessions weekly for at least 25 years (older trained, OT), and (3) 22 middle-aged (range 35-59 years) untrained women (middle-aged untrained, MU) as a reference control for the appropriate age-related changes. Oxygen uptake ( V ̇ O 2 ) and cardiovascular function (cardiac output ( Q ̇ ); stroke volume (SV) acetylene rebreathing) were examined at rest, steady-state submaximal exercise and maximal exercise (maximal oxygen uptake, V ̇ O 2 max ). Blood volume (CO rebreathing) and LV mass (cardiac magnetic resonance imaging), plus invasive measures of static and dynamic chamber compliance were also examined. V ̇ O 2 max (p < 0.001) and maximal exercise Q ̇ and SV were larger in older trained women compared to the two untrained groups (∼17% and ∼27% for Q ̇ and SV, respectively, versus MU; ∼40% and ∼38% versus OU, all p < 0.001). Blood volume (mL kg^-1 ) and LV mass index (g m^-2 ) were larger in OT versus OU (∼11% and ∼16%, respectively, both P ≤ 0.015) Static LV chamber compliance was greater in OT compared to both untrained groups (median (25-75%): MU: 0.065 (0.049-0.080); OU: 0.085 (0.061-0.138); OT: 0.047 (0.031-0.054), P ≤ 0.053). Collectively, these findings indicate that lifetime endurance exercise appears to be extremely effective at preserving or even enhancing cardiovascular structure and function with advanced age in women.

Effects of Caloric Restriction on Cardiorespiratory Fitness, Fatigue, and Disability Responses to Aerobic Exercise in Older Adults With Obesity: A Randomized Controlled Trial

BACKGROUND

Obesity compounds aging-related declines in cardiorespiratory fitness, with accompanying fatigue and disability. This study determined the effects of two different levels of caloric restriction (CR) during aerobic training on cardiorespiratory fitness, fatigue, physical function, and cardiometabolic risk.

METHODS

The INFINITE study was a 20-week randomized trial in 180 older (65-79 years) men and women with obesity (body mass index = 30-45 kg/m2). Participants were randomly assigned to (i) aerobic training (EX; treadmill 4 days/wk for 30 minutes at 65%-70% of heart rate reserve), (ii) EX with moderate (-250 kcal/d) CR (EX + Mod-CR), or (iii) EX with more intensive (-600 kcal/d) CR (EX + High-CR). Cardiorespiratory fitness (peak aerobic capacity, VO2 peak, primary outcome) was determined during a graded exercise test.

RESULTS

One hundred and fifty-five participants returned for 20-week data collection (87% retention). VO2 peak increased by 7.7% with EX, by 13.8% with EX + Mod-CR, and by 16.0% with EX + High-CR, and there was a significant treatment effect (EX + High-CR = 21.5 mL/kg/min, 95% confidence interval = 19.8-23.2; EX + Mod-CR = 21.2 mL/kg/min, 95% confidence interval = 19.4-23.0; EX = 20.1 mL/kg/min, 95% confidence interval = 18.4-21.9). Both CR groups exhibited significantly greater improvement in self-reported fatigue and disability and in glucose control, compared with EX.

CONCLUSION

Combining aerobic exercise with even moderate CR is more efficacious for improving cardiorespiratory fitness, fatigue and disability, and glucose control than exercise alone and is as effective as higher-dose CR.

Cardiac Pacemaker Activity and Aging

A progressive decline in maximum heart rate (mHR) is a fundamental aspect of aging in humans and other mammals. This decrease in mHR is independent of gender, fitness, and lifestyle, affecting in equal measure women and men, athletes and couch potatoes, spinach eaters and fast food enthusiasts. Importantly, the decline in mHR is the major determinant of the age-dependent decline in aerobic capacity that ultimately limits functional independence for many older individuals. The gradual reduction in mHR with age reflects a slowing of the intrinsic pacemaker activity of the sinoatrial node of the heart, which results from electrical remodeling of individual pacemaker cells along with structural remodeling and a blunted β-adrenergic response. In this review, we summarize current evidence about the tissue, cellular, and molecular mechanisms that underlie the reduction in pacemaker activity with age and highlight key areas for future work.

The importance of physical function as a clinical outcome: Assessment and enhancement

The burgeoning population of older adults is intrinsically prone to cardiovascular disease (CVD) in a context of multimorbidity and geriatric syndromes. Risks include high susceptibility to functional decline, with many older adults tipping towards patterns of sedentary behavior and to downstream effects of frailty, falls, disability, poor quality of life, as well as increased morbidity and mortality even if the incident CVD was treated perfectly. While physical activity has been shown to moderate these patterns both as primary or secondary preventive medical care, the majority of older adults fail to meet physical activity recommendations. Clinicians of all specialities, including CVD medicine, can benefit from greater proficiency in functional assessments for their older adults, as well as from insights how to initiate effective functional enhancing approaches even in older adults who may be frail, deconditioned, and medically complex. Pertinent functional assessments include traditional cardiovascular metrics of cardiorespiratory fitness, as well as strength and balance. This review summarizes the components of a wide-ranging functional assessment that can be used to enhance care for older adults with CVD, as well as interventions to improve physical function.

The effects of same-session combined exercise training on cardiorespiratory and functional fitness in older adults: a systematic review and meta-analysis

Endurance and strength training are effective strategies for counteracting age-associated reductions in physical performance in older adults, with a combination of both exercise modes recommended to maximise potential fitness benefits. This meta-analysis sought to quantify the effects of same-session combined endurance and strength training on fitness in adults aged over 50 years. Five electronic databases were searched with studies required to include one of the following outcome measures: VO_2peak, 6-min walk test (6MWT), 8-ft timed up-and-go (TUG), and 30-s chair stand. Separate random-effects meta-analyses compared combined training with (1) no-exercise control, (2) endurance training, and (3) strength training with probabilistic magnitude-based inferences subsequently applied. Twenty-seven studies involving 1346 subjects with a mean age of 68.8 years (range 54–85 years) were included in the analysis. The meta-analysed effect on VO_2peak was a moderately beneficial effect for the combined training compared to no-exercise controls (3.6 mL kg⁻¹ min⁻¹; ± 95% confidence limits 0.8 mL kg⁻¹ min⁻¹) with additional increases for studies with greater proportions of female participants and shorter training interventions. Combined training also had small-to-moderately beneficial effects on VO_2peak when compared to endurance training (0.8 mL kg⁻¹ min⁻¹; ± 1.0 mL kg⁻¹ min⁻¹), 30-s chair stand when compared with strength training (1.1 repetitions; ± 0.5 repetitions) and on TUG (0.8 s; ± 0.7 s), 30-s chair stand (2.8 repetitions; ± 1.7 repetitions), and 6MWT (31.5 m; ± 22.4 m) when compared to no-exercise controls. All other comparisons were unclear. Same-session combined training can induce clinically relevant fitness improvements in older adults.

Community exercise is feasible for neuromuscular diseases and can improve aerobic capacity

OBJECTIVE

The aim of this phase 2 trial was to ascertain the feasibility and effect of community-based aerobic exercise training for people with 2 of the more common neuromuscular diseases: Charcot-Marie-Tooth disease type 1A (CMT) and inclusion body myositis (IBM).

METHODS

A randomized single-blinded crossover trial design was used to compare a 12-week aerobic training program using recombinant exercise bicycles compared to a control period. The training occurred 3 times per week in community gyms local to the participants. Support was available from trained gym staff and a research physiotherapist. The 2 disease groups were analyzed separately. The primary outcome measure was peak oxygen uptake (VO2 peak) during a maximal exercise test, with secondary measures of muscle strength, function, and patient-reported measures.

RESULTS

Data from 23 people with CMT and 17 people with IBM were included in the analysis. Both disease groups had high levels of participation and demonstrated improvements in VO2 peak, with a moderate effect size in the CMT participants (Cohen d = 0.53) and a strong effect size in the IBM group (Cohen d = 1.72). No major changes were observed in the secondary outcome measures. Qualitative interviews revealed that participants valued the support of gym instructors and the research physiotherapists in overcoming challenges to participation.

CONCLUSION

Twelve weeks of aerobic training in community gyms was feasible, safe, and improved aerobic capacity in people with CMT and IBM.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that for patients with CMT type 1A and IBM, an aerobic training program increases aerobic capacity.

The role of dihydrosphingolipids in disease

Dihydrosphingolipids refer to sphingolipids early in the biosynthetic pathway that do not contain a C4-trans-double bond in the sphingoid backbone: 3-ketosphinganine (3-ketoSph), dihydrosphingosine (dhSph), dihydrosphingosine-1-phosphate (dhS1P) and dihydroceramide (dhCer). Recent advances in research related to sphingolipid biochemistry have shed light on the importance of sphingolipids in terms of cellular signalling in health and disease. However, dihydrosphingolipids have received less attention and research is lacking especially in terms of their molecular mechanisms of action. This is despite studies implicating them in the pathophysiology of disease, for example dhCer in predicting type 2 diabetes in obese individuals, dhS1P in cardiovascular diseases and dhSph in hepato-renal toxicity. This review gives a comprehensive summary of research in the last 10-15 years on the dihydrosphingolipids, 3-ketoSph, dhSph, dhS1P and dhCer, and their relevant roles in different diseases. It also highlights gaps in research that could be of future interest.

Chronic neurological disorders and related comorbidities: Role of age-associated physiological changes

Current knowledge indicates that the physiological aging process starts with subclinical changes at the molecular and cellular level, which affect nearly all physiological systems. For example, the age-associated remodeling of the immune system (i.e., immunosenescence) and vascular aging per se can contribute to frailty and vulnerability among older adults. They are also described as being implicated in the pathophysiology of some major chronic comorbid conditions such as age-associated diseases of the central (e.g., stroke, Parkinson's disease, Alzheimer's disease, and related disorders) and peripheral (e.g., polyneuropathy) nervous systems. These neurologic disorders are also among the greatest contributors to geriatric syndromes, which refer to highly prevalent and chronic conditions among aged people of multifactorial origin, such as delirium, falls, incontinence, and frailty. Neurologic disorders can also occur in patients with one or more geriatric syndromes and thus further interfere with the quality of life, physical function, morbidity, and mortality. This chapter presents and discusses in three sections the complex interrelationships between the main determinants of aging with a specific focus on vascular aging, chronic neurologic disorders, and the specific clinical presentation of geriatric syndromes in older people.

Cognitive and structural cerebral changes in amnestic mild cognitive impairment due to Alzheimer's disease after multicomponent training

Introduction

Information about how physical exercise affects patients with amnestic mild cognitive impairment (aMCI) due to Alzheimer's disease (AD) is still missing. This study evaluated the impact of multicomponent exercise training on cognition and brain structure in aMCI subjects with cerebral spinal fluid positive AD biomarkers.

Methods

Forty aMCI subjects were divided in training (multicomponent exercise thrice a week for 6 months) and nontraining groups. Assessments included cardiorespiratory fitness, neurocognitive tests, and a structural magnetic resonance imaging using 3.0 T scanner. FreeSurfer software analyzed hippocampal volume and cortical thickness.

Results

The training group showed increased volume in both hippocampi and better performance in episodic memory test after 6 months. In contrast, the nontraining group declined in functional activities, recognition, and cardiorespiratory fitness for the same period.

Discussion

Multicomponent exercise seems to improve hippocampal volume and episodic memory, and maintains VO_2max in aMCI due to AD.

PRIME: A Novel Low-Mass, High-Repetition Approach to Improve Function in Older Adults

INTRODUCTION

The ability to maintain functional independence in a rapidly aging population results in an increased life expectancy without corresponding increases in health care costs. The accelerated decline in V˙O2peak after the age of 65 yr is primarily due to peripheral tissue changes rather than centrally mediated factors. The purpose of this study was to determine whether the Peripheral Remodeling through Intermittent Muscular Exercise (PRIME) approach, consisting of a low-mass, high-repetition/duration skeletal muscle focused training regimen would provide superior functional benefits in participants older than 70 yr old and at risk for losing functional independence.

METHODS

In this clinical trial, 107 participants were randomized to 4 wk of either standard aerobic training (AT) or PRIME (phase 1). This was followed by 8 wk of a progressive whole-body aerobic and resistance training (AT + RT) for all participants (phase 2). The major outcome measures were cardiorespiratory fitness (peak oxygen consumption [V˙O2peak]), muscular fitness (1 repetition maximal strength [1RM]), and physical function (Senior Fitness Test [SFT] scores). Results were analyzed under a per-protocol criterion.

RESULTS

Thirty-eight PRIME and 38 AT participants completed the 3-month protocols. V˙O2peak, 1RM, and SFT scores all increased significantly after 12 wk for both treatment groups (P < 0.05). However, relative to AT, participants randomized to PRIME demonstrated a greater increase in V˙O2peak (2.37 + 1.83 vs 1.50 + 1.82 mL·kg·min, P < 0.05), 1RM (48.52 + 27.03 vs 28.01 + 26.15 kg, P < 0.01) and SFT (22.50 + 9.98 vs 18.66 + 9.60 percentile, P < 0.05).

CONCLUSIONS

Participants experienced greater increases in cardiorespiratory and muscular fitness and physical function when PRIME training was initiated before a combined AT + RT program. This novel exercise approach may be advantageous to individuals with other chronic disease conditions characterized by low functional capacity.

Lack of age-specific influence on leg blood flow during incremental calf plantar-flexion exercise in men and women

PURPOSE

Age-related exercising leg blood flow (LBF) responses during dynamic knee-extension exercise and forearm blood flow responses during handgrip exercise are preserved in normally active men but attenuated in activity-matched women. We explored whether these age- and sex-specific effects are also apparent during isometric calf plantar-flexion incremental exercise.

METHODS

Normally active young men (YM, n = 15, 24 ± 2 years), young women (YW, n = 8, 22 ± 1 years), older men (OM, n = 13, 70 ± 7 years) and older women (OW, n = 10, 64 ± 7 years) were tested. LBF was measured between contractions using venous occlusion plethysmography.

RESULTS

Peak force obtained was higher (P < 0.05) in men compared with women and in young compared with older individuals. However, peak LBF (YM; 971 ± 328 ml min^-1, OM; 985 ± 504 ml min^-1, YW; 844 ± 366 ml min^-1, OW; 960 ± 244 ml min^-1) and peak leg vascular conductance [LVC = LBF/(MAP + hydrostatic pressure)] responses (YM; 6.0 ± 1.8 ml min^-1 mmHg^-1, OM; 5.5 ± 2.8 ml min^-1 mmHg^-1, YW; 5.3 ± 2.1 ml min^-1 mmHg^-1, OW; 5.5 ± 1.6 ml min^-1 mmHg^-1) were similar among the four groups. Furthermore, the hyperaemic (YM; 8.8 ± 3.7 ml min^-1 %F_peak^-1 OM; 8.3 ± 5.4 ml min^-1 %F_peak^-1, YW; 8.2 ± 3.5 ml min^-1 %F_peak^-1, OW; 9.6 ± 2.2 ml min^-1 %F_peak^-1) and vasodilatory responses (YM; 0.053 ± 0.020 ml min^-1 mmHg^-1 %F_peak^-1, OM; 0.048 ± 0.028 ml min^-1 mmHg^-1 %F_peak^-1, YW; 0.051 ± 0.019 ml min^-1 mmHg^-1 %F_peak^-1, OW; 0.055 ± 0.014 ml min^-1 mmHg^-1 %F_peak^-1) were not different among the four groups. These results were accompanied by similar resting LBF responses among groups and were not affected when data were normalised to estimated leg muscle mass.

CONCLUSIONS

Our results demonstrate that exercising LBF responses during isometric incremental calf muscle exercise are preserved in older men and women, suggesting that the previously observed age-related attenuations in leg and forearm hyperaemia among women may be muscle-group specific.

Concurrent measurement of skeletal muscle blood flow during exercise with diffuse correlation spectroscopy and Doppler ultrasound

Noninvasive, direct measurement of local muscle blood flow in humans remains limited. Diffuse correlation spectroscopy (DCS) is an emerging technique to measure regional blood flow at the microvascular level. In order to better understand the strengths and limitations of this novel technique, we performed a validation study by comparing muscle blood flow changes measured with DCS and Doppler ultrasound during exercise. Nine subjects were measured (all males, 27.4 ± 2.9 years of age) for a rhythmic handgrip exercise at 20% and 50% of individual maximum voluntary contraction (MVC), followed by a post-exercise recovery. The results from DCS and Doppler ultrasound were highly correlated (R = 0.99 ± 0.02). DCS was more reliable and less susceptible to motion artifact.

Similar pattern of change in V̇o2 kinetics, vascular function, and tissue oxygen provision following an endurance training stimulus in older and young adults

The purpose of this study was to examine the time course of changes in the oxygen uptake (V̇o₂) kinetics response subsequent to short-term exercise training (i.e., 24, 48, 72, and 120 h posttraining) and examine the relationship with the time course of changes in microvascular [deoxygenated hemoglobin concentration ([HHb])-to-V̇o₂ ratio ([HHb])/V̇o₂)] and macrovascular [flow-mediated dilation (FMD)] O₂ delivery to the active tissues/limbs. Seven healthy older [OA; 74 ± 6 (SD) yr] and young men (YA; 25 ± 3 yr) completed three endurance cycling exercise training sessions at 70% V̇o_2peak Moderate-intensity exercise on-transient V̇o₂ (measured breath by breath) and [HHb] (measured by near-infrared spectroscopy) were modeled with a monoexponential and normalized (0-100% of response), and the [HHb])/V̇o₂ was calculated. Ultrasound-derived FMD of the popliteal artery was assessed after 5 min of cuff occlusion. %FMD was calculated as the greatest percent change in diameter from baseline. Time constant of V̇o₂ (τV̇o₂) was significantly reduced in both OA (~18%) and YA (~23%) at 24 h (P < 0.001) posttraining and remained decreased at 48 h before returning toward pretraining (PRE) values. Both groups showed a significant decrease in the [HHb])/V̇o₂ at 24, 48, and 72 h (P = 0.001, 0.01, and 0.03, respectively) posttraining before returning toward PRE values at 120 h. %FMD followed a similar time course to that of changes in the [HHb])/V̇o₂, being significantly greater in both OA (by ~64%) and YA (by ~26%) at 24 h (P < 0.001), remaining increased at 48 and 72 h (P = 0.02 and 0.03, respectively), and returning toward PRE values at 120 h. These data suggest the rate of adjustment of V̇o₂ may be constrained by O₂ availability in the active tissues.

Effect of a 6-Month Brisk Walking Program on Walking Endurance in Sedentary and Physically Deconditioned Women Aged 60 or Older: A Randomized Trial

BACKGROUND

Walking endurance is a predictor of healthy ageing.

OBJECTIVE

To examine if a 6-month brisk walking program can increase walking endurance in sedentary and physically deconditioned older women.

TRIAL DESIGN

Randomized controlled trial.

SETTING

Women recruited from public meetings aimed at promoting physical activity in women aged 60 or older.

SUBJECTS

121 women aged 65.7 ± 4.3 years, with sedentary lifestyle (Physical Activity Questionnaire for the Elderly score < 9.4), and a 6-minute walking distance (6MWD) below normal value based on their gender, age, and body weight, and weight.

METHODS

Women were randomly assigned to a 150 min/week brisk walking program (two supervised sessions and one session on their own per week) for six months (exercisers) (n=61) or a control group with physical activity allowed freely (n=60).

OUTCOME

The primary outcome was relative change in 6MWD.

RESULTS

54/61 exercisers and 55/60 control subjects completed the program and data analysis was possible for 51 exercisers and 47 controls. At baseline, 6MWD was on average 23.1% and 22.5% below age-matched norms in exercisers and controls, respectively. Attendance rate for supervised sessions was 92% in exercisers. The 6MWD increased more significantly in exercisers than in controls (mean increase of 41.5% vs 11.0 %; p<0.0001). Over the 6-month program, 38 exercisers (74.5%) vs 5 controls (10.6%) had a 6MWD over the age-matched norm (p<0.0001). Exercisers with the highest tertile of 6MWD improvement (>46%) were those with baseline lowest values of 6MWD (p=0.001) and highest values of body mass index (BMI) (p<0.01).

CONCLUSION

Present results support recommendation that brisk walking programs should be encouraged to improve walking endurance in physically deconditioned women aged 60 or older, especially in those with high BMI.

Neighbourhood greenspace is associated with a slower decline in physical activity in older adults: A prospective cohort study

Maintaining physical activity in later life is important for maintaining health and function. Activity outdoors, such as walking, jogging and cycling, may provide an accessible, sociable and practical solution, but maintaining outdoor mobility may be a challenge in later life. Providing green environments which are supportive of physical activity may facilitate this, yet research into how greenspace could be best used is inconclusive. This study evaluates the role of greenspace in protecting against decline in physical activity over time in older adults. Data from the European Prospective Investigation of Cancer Norfolk, UK, cohort 1993-2009 (N=15,672) was used. Linear regression modelling was used to examine the association between exposure to greenspace in the home neighbourhood and change in overall, recreational and outdoor physical activity measured in terms of metabolic equivalent cost (MET) in hours/week. Mediation analysis was conducted to assess if dog walking explained the relationship between greenspace and physical activity change. Models were adjusted for known and hypothesised confounders. People living in greener neighbourhoods experienced less of a decline in physical activity than those living in less green areas. Comparing change for those living in the greenest versus least green quartiles, participants showed a difference in overall physical activity of 4.21 MET hours/week (trend P=0.001), adjusted for baseline physical activity, age, sex, BMI, social class and marital status. This difference was 4.03 MET hours/week for recreational physical activity (trend P<0.001) and 1.28 MET hours/week for outdoor physical activity (trend P=0.007). Dog walking partially mediated the association between greenspace and physical activity change, by 22.6% for overall, 28.1% for recreational and 50.0% for outdoor physical activity (all P<0.001). Greenspace in the home neighbourhood may be protective against decline in physical activity among older people as they age. Dog walking is a potential mechanism in this relationship, and warrants further investigation as a way of maintaining physical activity in later life.

Exercise prescription to reverse frailty

Frailty is a clinical geriatric syndrome caused by physiological deficits across multiple systems. These deficits make it challenging to sustain homeostasis required for the demands of everyday life. Exercise is likely the best therapy to reverse frailty status. Literature to date suggests that pre-frail older adults, those with 1–2 deficits on the Cardiovascular Health Study-Frailty Phenotype (CHS-frailty phenotype), should exercise 2–3 times a week, for 45–60 min. Aerobic, resistance, flexibility, and balance training components should be incorporated but resistance and balance activities should be emphasized. On the other hand, frail (CHS-frailty phenotype ≥ 3 physical deficits) older adults should exercise 3 times per week, for 30–45 min for each session with an emphasis on aerobic training. During aerobic, balance, and flexibility training, both frail and pre-frail older adults should work at an intensity equivalent to a rating of perceived exertion of 3–4 (“somewhat hard”) on the Borg CR10 scale. Resistance-training intensity should be based on a percentage of 1-repetition estimated maximum (1RM). Program onset should occur at 55% of 1RM (endurance) and progress to higher intensities of 80% of 1RM (strength) to maximize functional gains. Exercise is the medicine to reverse or mitigate frailty, preserve quality of life, and restore independent functioning in older adults at risk of frailty.

Effects of Aging and Exercise on the Cardiorespiratory Fitness of Older Women

Abstract Purpose: The present study analyzed the effects of chronological aging and the practice of regular exercise (PRE) on the cardiorespiratory fitness (CRF) of older women. Methods: A descriptive study of 78 participants was performed, with longitudinal design and an initial evaluation in 2005 and a second in 2011. The PRE defined groups as Inactive (I), Insufficiently-Active (IA), and Sufficiently-Active (SA). The six-minute walking test measured CRF. MANOVA with repeated-measures was used to verify the effect of time and the PRE groups on CRF (p<0.05). Results: The participants were classified as having a low socioeconomic level and being overweight. MANOVA demonstrated the effect of time (F1.74=30.134; p<0.05) and groups (F2.74=3.729; p<0.05), without interaction (F2.74=0.811; p>0.05). Post hoc analysis indicated that the effect of time was significant between all groups (I: t=3.786, p<0.05; IA: t=2.597, p<0.05; SA: t=3.191, p<0.05); and the group effect was significant only between the I and SA groups in the second evaluation (First evaluation: F2.76=1.712; p>0.05; Second Evaluation: F2.77=3.239; p<0.05, post hoc Tukey: group I vs AS =p<0.05). A smaller reduction in CRF was found in the SA group (8.0%), followed by the IA (10.3%) and I (14.3%) groups. Conclusion: The results of the present study indicated that elderly women who practice exercise regularly had a smaller reduction in CRF than those who were inactive. This suggests that the PRE at recommended levels for health purposes can attenuate the effect of aging on the CRF.

Fitness but not weight status is associated with projected physical independence in older adults

Obesity and fitness have been associated with older adults' physical independence. We aimed to investigate the independent and combined associations of physical fitness and adiposity, assessed by body mass index (BMI) and waist circumference (WC) with the projected ability for physical independence. A total of 3496 non-institutionalized older adults aged 65 and older (1167 male) were included in the analysis. BMI and WC were assessed and categorized according to established criteria. Physical fitness was evaluated with the Senior Fitness Test and individual test results were expressed as Z-scores. Projected ability for physical independence was assessed with the 12-item composite physical function scale. Logistic regression was used to estimate the odds ratio (OR) for being physically dependent. A total of 30.1 % of participants were classified as at risk for losing physical independence at age 90 years. Combined fitness and fatness analysis demonstrated that unfit older adults had increased odds ratio for being physically dependent in all BMI categories (normal: OR = 9.5, 95 %CI = 6.5-13.8; overweight: OR = 6.0, 95 %CI = 4.3-8.3; obese: OR = 6.7, 95 %CI = 4.6-10.0) and all WC categories (normal: OR = 10.4, 95%CI = 6.5-16.8; middle: OR = 6.2, 95 %CI = 4.1-9.3; upper: OR = 7.0, 95 %CI = 4.8-10.0) compared to fit participants that were of normal weight and fit participants with normal WC, respectively. No increased odds ratio was observed for fit participants that had increased BMI or WC. In conclusion, projected physical independence may be enhanced by a normal weight, a normal WC, or an increased physical fitness. Adiposity measures were not associated with physical independence, whereas fitness is independently related to physical independence. Independent of their weight and WC status, unfit older adults are at increased risk for losing physical independence.

Preventing Loss of Basic Activities of Daily Living and Instrumental Activities of Daily Living in Elderly: Identification of Individual Risk Factors in a Holistic Perspective

This study investigated the association between physical functioning and activities of daily living (ADL) of elderly people, taking into account the role of cognitive, psychological, and social factors. We administered physical, cognitive, psychological, and social instruments to investigate the level of basic and instrumental activities of daily living (BADL and IADL). The analysis showed that physical functioning was the only individual factor that was significantly linked with the level of BADL and IADL. This study underlines that physical functioning is the main individual characteristic directly associated with the level of BADL and IADL in old age.

Functional Status and Social Contact Among Older Adults

This article tests whether functional status is associated with likelihood of social contact among older adults. Data come from the Second Longitudinal Study on Aging, a longitudinal nationally representative sample of 9,447 noninstitutionalized individuals aged 70 and over at baseline in 1995. Functional status is measured using an index of activities of daily living (ADL) and instrumental activities of daily living (IADL). Social contact is measured by asking respondents whether they had gotten together socially or talked on the phone with friends/neighbors or family in the past 2 weeks. Greater number of functional limitations is associated with a decreased likelihood of social contact at follow-up via the phone with friends (odd ratio [OR] = 0.94, p < .01) and family (OR = 0.96, p < .01), and a decreased likelihood of getting together with friends (OR = 0.93, p < .01) and family (OR = 0.97, p < .01). Results indicate that functional limitations have a broad impact on self-reported social contact among older adults.

Effects of endurance, circuit, and relaxing training on cardiovascular risk factors in hypertensive elderly patients

Recommendations for prevention of cardiovascular diseases (CVDs) risk factors among older adults highlighted the importance of exercise-based interventions, including endurance training (ET). However, the evidence of efficacy of other interventions based on short-bouts of exercise (circuit training, CT), and the practice of breath-control and meditation (relaxing training, RT) is growing. The aim of this study was to elucidate if CT or RT are equally effective in CVD risk factors reduction compared to ET. To this purpose, in 40 elderly participants, with clinically diagnosed grade 1 hypertension, resting blood pressure, blood glucose, and cholesterol levels, peak oxygen uptake ([Formula: see text]), mechanical efficiency and quality of life were evaluated before and after 12 weeks of ET, CT, and RT treatments. Resting blood pressure reduced significantly in all groups by ∼11 %. In ET, blood cholesterol levels (-18 %), [Formula: see text] (+8 %), mechanical efficiency (+9 %), and quality of life scores (+36 %) ameliorated. In CT blood glucose levels (-11 %), [Formula: see text] (+7 %) and quality of life scores (+35 %) were bettered. Conversely, in RT, the lower blood pressure went along only with an improvement in the mental component of quality of life (+42 %). ET and CT were both appropriate interventions to reduce CVDs risk factors, because blood pressure reduction was accompanied by decreases in blood glucose and cholesterol levels, increases in [Formula: see text], mechanical efficiency, and quality of life. Although RT influenced only blood pressure and quality of life, this approach would be an attractive alternative for old individuals unable or reluctant to carry out ET or CT.

A cluster randomised feasibility trial evaluating nutritional interventions in the treatment of malnutrition in care home adult residents

Background

Protein energy malnutrition (PEM) predisposes individuals to disease, delays recovery from illness and reduces quality of life. Care home residents in the United Kingdom are especially vulnerable, with an estimated 30 to 42 % at risk. Evidence for nutritional interventions to address PEM in the care home setting is lacking. Widely used techniques include food-based intervention and/or the use of prescribed oral nutritional supplements. To define outcomes and optimise the design for an adequately powered definitive trial to compare the efficacy of established nutritional interventions in this setting, a cluster randomised feasibility trial with a 6-month intervention was undertaken.

Methods

Care home residents with or at risk of malnutrition were identified across six UK care home sites from September to December 2013. Homes were cluster randomised to standard care (SC), food-based intervention (FB) or oral nutritional supplement intervention (ONS), for 6 months. Key outcomes were trial feasibility and the acceptability of design, allocated interventions and outcome assessments. Anthropometry, dietary intake, healthcare resource usage and participant-reported outcome measures were assessed at baseline and at 3 and 6 months.

Results

All six care homes approached were recruited and retained. Of the 110 residents at risk of malnutrition, 85 % entered the trial, and 68 % completed the 6-month intervention. Pre-specified success criteria for feasibility were met for recruitment and retention, intervention acceptability (resident compliance ≥60 %) and measurement of weight, body mass index (BMI), mid-upper arm circumference and dietary intake (data completeness >80 %). Measurement of handgrip strength and triceps skinfold thickness was not found to be feasible in this population. The 95 % confidence interval (CI) data suggested sensitivity to change in dietary intake for weight, BMI and energy intake between baseline and 3 months when each intervention (FB and ONS) was compared with SC.

Conclusions

A definitive trial comparing the efficacy of nutritional support interventions in increasing weight and BMI in malnourished care home residents can be conducted. However, whilst the design was feasible, this trial has highlighted the lack of clinically and patient-relevant outcome measures that are appropriate for use in this setting for both research and clinical practice. In particular, this trial identified a need for a more simple measure of functional status, which considers the limitations of functional tests in the care home population.

Trial registration

Current Controlled Trials ISRCTN38047922, Date assigned: 22 April 2014.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-015-0952-2) contains supplementary material, which is available to authorized users.

Criterion-referenced fitness standards for predicting physical independence into later life

OBJECTIVES

The aim of the current study was to develop sex and age-adjusted criterion-referenced fitness standards to predict independent physical functioning into later life.

DESIGN

Cross-sectional.

SETTING

National Survey of Physical Fitness and Physical Activity, Portugal.

PARTICIPANTS

A national representative sample of 3074 non-institutionalized older adults (65-84years).

MEASUREMENTS

Projected capacity for physical independence was assessed by the Composite Physical Function (CPF) scale, and physical fitness was assessed using the Senior Fitness Test battery. ROC analyses were used to evaluate the classification accuracy of physical fitness components, and determine the best cutoff values of functional fitness to predict loss of independence. Stepwise multivariate logistic regression was used to identify sex and age category fitness components that were predictors of independence with follow-up ROC analysis to verify the model's discriminative capability.

RESULTS

ROC curve analysis showed that the fitness tests were good in diagnosing physical independence (AUC>0.7). Logistic regression models demonstrated that different fitness components should be targeted according to age and sex, but with an emphasis on aerobic endurance and agility/dynamic balance. Overall, models provided higher AUC (males: 0.79-0.86; females: 0.73-0.85) when comparing the best fitness tests for each sex and age category. The sensitivity of newly developed models ranged from 80.5 to 87.7 in males and from 68.2 to 86.3 in females, while the specificity ranged from 62.1 to 73.8 in males and between 58.2 and 82.9 in females.

CONCLUSION

The Senior Fitness Test provides a good field tool that allows the identification of fitness levels that older adults need to achieve to be physically independent later in life, and permits the accurate planning and implementation of exercise-based interventions for older adults.

Development of an assistive motorized hip orthosis: kinematics analysis and mechanical design

With the increase of life expectancy, a higher number of elderly need assistance to maintain their mobility and their independance. The hip joint is crucial for walking and is problematic for a large number of aged people. In this paper we present a novel design of a motorized hip orthosis to assist elderly people while walking, stair climbing and during the sit-to-stand transistions. The kinematics was developed based on biomechanics considerations. To be able to achieve a large assistance rate, velocity and torques of the hip joint were studied from the literature. In order to fit with these requirements, an amplification mechanism inspired by excavators was developed and implemented. Comfort considerations were also taken into account and a custom interface was designed with the collaboration of a professional orthopaedic technician. First tests with the prototype showed that the workspace is sufficient for walking, for stair climbing as well as for sit-to-stand transitions. The assistance rate can go up to 30% for a 70 kg subject during walking at a cadence of 100 steps/min. The comfort is guaranteed despite the important weight (4.3 kg) of this first prototype.

Exercise as a therapeutic strategy for primary mitochondrial cytopathies

Patients with mitochondrial cytopathies often experience exercise intolerance and may have fixed muscle weakness, leading to impaired functional capacity and lower quality of life. Endurance exercise training increases Vo 2 max, respiratory chain enzyme activity, and improves quality of life. Resistance exercise training increases muscle strength and may lower mutational burden in patients with mitochondrial DNA deletions. Both modes of exercise appear to be well tolerated. Patients with mitochondrial cytopathy should consider alternating both types of exercise to derive the benefits from each (endurance = greater aerobic fitness; resistance = greater strength). Patients should start an exercise program at a low intensity and duration, gradually increasing duration and intensity. They should "listen to their body" and not exercise on days they have fever, superimposed illness, muscle pain, or cramps, and/or if they have fasted for more than 12 hours. Children often respond best to play-based exercise and tend to enjoy intermittent activity.

Resveratrol modulates the angiogenic response to exercise training in skeletal muscles of aged men

In animal studies, the polyphenol resveratrol has been shown to influence several pathways of importance for angiogenesis in skeletal muscle. The aim of the present study was to examine the angiogenic effect of resveratrol supplementation with parallel exercise training in aged men. Forty-three healthy physically inactive aged men (65 ± 1 yr) were divided into 1) a training group that conducted 8 wk of intense exercise training where half of the subjects received a daily intake of either 250 mg trans-resveratrol (n = 14) and the other half received placebo (n = 13) and 2) a nontraining group that received either 250 mg trans-resveratrol (n = 9) or placebo (n = 7). The group that trained with placebo showed a ~20% increase in the capillary-to-fiber ratio, an increase in muscle protein expression of VEGF, VEGF receptor-2, and tissue inhibitor of matrix metalloproteinase (TIMP-1) but unaltered thrombospodin-1 levels. Muscle interstitial VEGF and thrombospodin-1 protein levels were unchanged after the training period. The group that trained with resveratrol supplementation did not show an increase in the capillary-to-fiber ratio or an increase in muscle VEGF protein. Muscle TIMP-1 protein levels were lower in the training and resveratrol group than in the training and placebo group. Both training groups showed an increase in forkhead box O1 protein. In nontraining groups, TIMP-1 protein was lower in the resveratrol-treated group than the placebo-treated group after 8 wk. In conclusion, these data show that exercise training has a strong angiogenic effect, whereas resveratrol supplementation may limit basal and training-induced angiogenesis.