Nº de abstracts = 18

Modificado em 23 Fevereiro 2012

Resistance exercise for muscular strength in older adults: a meta-analysis.

Peterson MD, Rhea MR, Sen A, Gordon PM.: Ageing research reviews, 2010 9(3):226-37. Laboratory for Physical Activity and Exercise Intervention Research, Department of Physical Medicine and Rehabilitation, University of Michigan, Ann Arbor, MI 48108, USA

PURPOSE: The effectiveness of resistance exercise for strength improvement among aging persons is inconsistent across investigations, and there is a lack of research synthesis for multiple strength outcomes. METHODS: The systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations. A meta-analysis was conducted to determine the effect of resistance exercise (RE) for multiple strength outcomes in aging adults. Randomized-controlled trials and randomized or non-randomized studies among adults > or = 50 years, were included. Data were pooled using random-effect models. Outcomes for 4 common strength tests were analyzed for main effects. Heterogeneity between studies was assessed using the Cochran Q and I(2) statistics, and publication bias was evaluated through physical inspection of funnel plots as well as formal rank-correlation statistics. A linear mixed model regression was incorporated to examine differences between outcomes, as well as potential study-level predictor variables. RESULTS: Forty-seven studies were included, representing 1079 participants. A positive effect for each of the strength outcomes was determined however there was heterogeneity between studies. Regression revealed that higher intensity training was associated with greater improvement. Strength increases ranged from 9.8 to 31.6 kg, and percent changes were 29+/-2, 24+/-2, 33+/-3, and 25+/-2, respectively for leg press, chest press, knee extension, and lat pull. CONCLUSIONS: RE is effective for improving strength among older adults, particularly with higher intensity training. Findings therefore suggest that RE may be considered a viable strategy to prevent generalized muscular weakness associated with aging.

Gait Speed and Survival in Older Adults

Stephanie Studenski, Subashan Perera, Kushang Patel, Caterina Rosano, Kimberly Faulkner, Marco Inzitari, Jennifer Brach, Julie Chandler, Peggy Cawthon, Elizabeth Barrett Connor, Michael Nevitt, Marjolein Visser, Stephen Kritchevsky, Stefania Badinelli, Tamara Harris, Anne B. Newman, Jane Cauley, Luigi Ferrucci, Jack Guralnik: JAMA, January 5, 2011, Vol 305, No. 1, pp 13-1042.

Context Survival estimates help individualize goals of care for geriatric patients, but life tables fail to account for the great variability in survival. Physical performance measures, such as gait speed, might help account for variability, allowing clinicians to make more individualized estimates.Objective To evaluate the relationship between gait speed and survival.

Design, Setting, and Participants Pooled analysis of 9 cohort studies (collected between 1986 and 2000), using individual data from 34 485 community-dwelling older adults aged 65 years or older with baseline gait speed data, followed up for 6 to 21 years. Participants were a mean (SD) age of 73.5 (5.9) years; 59.6%, women; and 79.8%, white; and had a mean (SD) gait speed of 0.92 (0.27) m/s.Main Outcome Measures Survival rates and life expectancy.Results There were 17 528 deaths; the overall 5-year survival rate was 84.8% (confidence interval [CI], 79.6%-88.8%) and 10-year survival rate was 59.7% (95% CI, 46.5%-70.6%). Gait speed was associated with survival in all studies (pooled hazard ratio per 0.1 m/s, 0.88; 95% CI, 0.87-0.90; P < .001). Survival increased across the full range of gait speeds, with significant increments per 0.1 m/s. At age 75, predicted 10-year survival across the range of gait speeds ranged from 19% to 87% in men and from 35% to 91% in women. Predicted survival based on age, sex, and gait speed was as accurate as predicted based on age, sex, use of mobility aids, and self-reported function or as age, sex, chronic conditions, smoking history, blood pressure, body mass index, and hospitalization.

Conclusion In this pooled analysis of individual data from 9 selected cohorts, gait speed was associated with survival in older adults.

Less exercise and more TV: leisure-time physical activity trends of Shanghai elders, 1998-2008. Feng Q, Purser JL, Zhen Z, Duncan PW

Journal of public health (Oxford, England) 33(4):543-50, 2011 dez Division of Physical Therapy, Department of Community and Family Medicine, Duke University Medical Center, 2200 West Main Street, Suite B230, Durham, NC 27708, USA.

BACKGROUND: Surveillance of physical activity trends in older adults is limited in developing nations. This study examined 10-year leisure-time physical activity trends of elderly residents of Shanghai, the largest Chinese city with the nation's highest proportion of senior citizens.

METHODS: The study used panel data from the Shanghai Longitudinal Survey of Elderly Life and Opinion (1998, 2003, 2005 and 2008). Leisure-time physical activity questions included (i) 16 major leisure-time habitual activities and (ii) regular exercise in the previous 6 months.

RESULTS: In comparison to 1998, for Shanghai elders, the trend for engaging in leisure-time habits not related to physical activity increased over time, becoming statistically significant in 2005 and 2008 (e.g. OR for watching TV in 2003, 2005 and 2008 is 1.04 [0.91, 1.19], 1.17 [1.00, 1.38] and 1.78 [1.51, 2.09], respectively). Simultaneously, the trend for engaging in regular exercise declined significantly in each observation year in comparison to 1998 (OR in 2003, 2005 and 2008 is 0.70 [0.61, 0.80], 0.36 [0.30, 0.42] and 0.28 [0.24, 0.33], respectively). Discussion An increasingly sedentary lifestyle has evolved over the past decade in Shanghai. This highlights a need for public health agencies to develop effective active lifestyle interventions and physical activity promotion programs for local elders.

Gait Speed and Survival in Older Adults

Stephanie Studenski, Subashan Perera, Kushang Patel, Caterina Rosano, Kimberly Faulkner, Marco Inzitari, Jennifer Brach, Julie Chandler, Peggy Cawthon, Elizabeth Barrett Connor, Michael Nevitt, Marjolein Visser, Stephen Kritchevsky, Stefania Badinelli, Tamara Harris, Anne B. Newman, Jane Cauley, Luigi Ferrucci, Jack Guralnik: JAMA, January 5, 2011, Vol 305, No. 1, pp 13-1042.

Context Survival estimates help individualize goals of care for geriatric patients, but life tables fail to account for the great variability in survival. Physical performance measures, such as gait speed, might help account for variability, allowing clinicians to make more individualized estimates.

Objective To evaluate the relationship between gait speed and survival.

Design, Setting, and Participants Pooled analysis of 9 cohort studies (collected between 1986 and 2000), using individual data from 34 485 community-dwelling older adults aged 65 years or older with baseline gait speed data, followed up for 6 to 21 years. Participants were a mean (SD) age of 73.5 (5.9) years; 59.6%, women; and 79.8%, white; and had a mean (SD) gait speed of 0.92 (0.27) m/s.

Main Outcome Measures Survival rates and life expectancy.

Results There were 17 528 deaths; the overall 5-year survival rate was 84.8% (confidence interval [CI], 79.6%-88.8%) and 10-year survival rate was 59.7% (95% CI, 46.5%-70.6%). Gait speed was associated with survival in all studies (pooled hazard ratio per 0.1 m/s, 0.88; 95% CI, 0.87-0.90; P < .001). Survival increased across the full range of gait speeds, with significant increments per 0.1 m/s. At age 75, predicted 10-year survival across the range of gait speeds ranged from 19% to 87% in men and from 35% to 91% in women. Predicted survival based on age, sex, and gait speed was as accurate as predicted based on age, sex, use of mobility aids, and self-reported function or as age, sex, chronic conditions, smoking history, blood pressure, body mass index, and hospitalization.

Conclusion In this pooled analysis of individual data from 9 selected cohorts, gait speed was associated with survival in older adults.

A half-mile walk decreases visual acuity in active older people.

De Oliveira Filho CW, Dias RG, Tavares GM, Santos GM, Mazo GZ.: Perceptual and Motor Skills, 2010, 110(3 Pt 2):1013-4. Department of Physical Education, São Paulo Federal University, Brazil.

The influence of a half-mile walk on the visual acuity of older people who engaged in physical activity was examined. 91 elderly people of both sexes (20 men, 71 women; M age = 69 yr., SD = 6) participated. All were assessed before and after the half-mile walking test for visual acuity (Snellen Optotype Scale) and heart rate. The data indicated a significant decrease in visual acuity as a result of the half-mile test.

Neighborhood walkability and sedentary time in Belgian adults.

Van Dyck D, Cardon G, Deforche B, Owen N, Sallis JF, De Bourdeaudhuij I.: American Journal of Preventive Medicine, 2010, 39(1):25-32. Fund for Scientific Research Flanders (FWO), Ghent University, Ghent, Belgium. Delfien.

BACKGROUND: Sedentary behavior (too much sitting) has deleterious health consequences that are distinct from lack of physical activity (too little exercise). PURPOSE: This study aimed to examine the associations of neighborhood walkability and sociodemographic factors with adults' self-reported and objectively assessed sedentary time. METHODS: This Belgian cross-sectional study was conducted between May 2007 and September 2008. Twenty-four neighborhoods were stratified on GIS-based walkability and neighborhood SES. In all, 1200 adults (aged 20-65 years; 50 per neighborhood; 42.7 [SD=12.6] years; 47.9% men) completed a sociodemographic survey and the International Physical Activity Questionnaire. They also wore an accelerometer for 7 days: Sedentary time was identified as accelerometer counts of less than 100 per minute. Statistical analyses were performed in 2009, using multilevel regression models, adjusted for physical activity levels and individual SES. RESULTS: Residents of high-walkable neighborhoods reported more sitting time than those of low-walkable neighborhoods (439.8 vs 403.4 minutes/day of daily sitting time, p<0.05). Living in high-walkable versus low-walkable neighborhoods was also associated with 2.9% more accelerometer-measured overall sedentary time (p<0.001). Being male, younger, unemployed, more highly educated, having a white-collar job (analysis for employed adults only), and living without children were all significantly associated with more sitting time. CONCLUSIONS: Contrary to expectations, living in a high-walkable neighborhood was associated with higher levels of sedentary time. If future studies in other contexts confirm these associations, environmental and policy innovations aiming to promote physical activity may need to address the potential negative health impact of sedentary behavior.

Seventy-year-old habitual volleyball players have larger tibial cross-sectional area and may be differentiated from their age-matched peers by the osteogenic index in dynamic performance.

Rantalainen T, Linnamo V, Komi PV, Selänne H, Heinonen A.: European Journal of Applied Physiology, 2010, 109(4):651-8. Neuromuscular Research Centre, Department of Biology of Physical Activity, University of Jyväskylä, P. O. Box 35, 40014 Jyväskylä, Finland.

The osteogenicity of a given exercise may be estimated by calculating an osteogenic index (OI) consisting of magnitude and rate of strain. Volleyball involves repetitive jumping and requires high power output and thus may be expected to be beneficial to bone and performance. The purpose of the present study was to examine if habitual volleyball playing is reflected in OI. Ten elderly habitual volleyball players [age 69.9 (SD 4.4) years] and ten matched controls volunteered [age 69.7 (4.2) years] as subjects. Distal tibia (d), tibial mid-shaft (50) and femoral neck (FN) bone characteristics were measured using pQCT and DXA. To estimate skeletal rigidity, cross-sectional area (ToA(50)), and compressive (BSI(d)) and bending strength indices (SSImax(50)) were calculated. Maximal performance was assessed with eccentric ankle plantar flexion, isometric leg press and countermovement jump (CMJ). A fast Fourier transform (FFT) was calculated from the acceleration of the center of mass during the CMJ. Maximal acceleration (MAG) and mean magnitude frequency (MMF) were selected to represent the constituents of OI. OI was calculated as the sum of the products of magnitudes and corresponding frequencies. Volleyball players had 7% larger ToA(50) and 37% higher power in CMJ, 15% higher MAG and 36% higher OI (P or= 0.646). In conclusion, habitual volleyball players may be differentiated from their matched peers by their dynamic jumping performance, and the differences are reflected in the magnitude but not rate of loading.

Individual, social environmental and physical environmental barriers to achieving 10 000 steps per day among older women.

Hall KS, McAuley E.: Health Education Research, 2010, 25(3):478-88. Geriatric Research, Education,.linical Center, Veterans Affairs Medical Center, 508 Fulton Street, GRECC 182, Durham, NC 27705, USA.

This study examined the determinants of attaining/not attaining 10 000 steps per day among older women. Methods: Daily step counts over 7 days were measured using accelerometry. Self-reported environmental characteristics, self-efficacy, social support and functional limitations were assessed in 128 older women. The presence of areas for activity within 1 km of each participant's residence was assessed using Geographic Information Systems. Multivariate analysis of variances were used to examine the degree to which these groups differed on measured constructs, and discriminant analysis was used to determine the profiles that discriminate among those who did not attain 10 000 steps per day and those who did. Results: Participants who did not attain 10 000 steps per day reported lower self-efficacy (P < 0.05), greater functional limitations (P < 0.05), had significantly fewer walking paths (P < 0.05) within 1 km of their home and reported significantly less street connectivity (P < 0.05) and safety from traffic (P < 0.05) than those who achieved 10 000 steps per day. Conclusion: Lack of perceived and actual environmental supports for walking, more functional limitations and lower self-efficacy are barriers to achieving 10 000 steps per day. The absence of these individual and environmental characteristics inhibits walking behavior in older women and should be considered in campaigns to promote a physically active lifestyle.

Falls among adults: the association of cardiorespiratory fitness and physical activity with walking-related falls.

Mertz KJ, Lee DC, Sui X, Powell KE, Blair SN.: American Journal of Preventive Medicine, 2010, 39(1):15-24. Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA.

BACKGROUND: Falls are a major cause of deaths, hospitalizations, and emergency room visits in the U.S., but circumstances surrounding falls are not well described. Among the elderly, balance and gait disorders and muscle weakness are associated with increased risk for falling, but the relationship of cardiorespiratory fitness and physical activity with falls is unclear. PURPOSE: This purpose of this study is to describe characteristics of falls among adults and assess the association of cardiorespiratory fitness and physical activity with walking-related falls. METHODS: Data on participants enrolled in the Aerobics Center Longitudinal Study (ACLS) from 1970 through 1989 who responded to questions on falls on the 1990 follow-up survey were analyzed in 2008-2009. The percentage of participants reporting at least one fall during the year before the follow-up survey was calculated and the activities at the time of falling were described. The relative risk and 95% CIs for the association of baseline fitness and physical activity with walking-related falls were calculated and logistic regression models for walking-related falls were developed. RESULTS: Of 10,615 participants aged 20-87 years, 20% (95% CI=19%, 21%) reported falling during the past year. Of those falling, 54% (95% CI=52%, 56%) fell during sports or exercise; 15% (95% CI=14%,17%) while walking; and 4% (95% CI=3%, 5%) from a stool or ladder. People aged >or=65 years were no more likely than younger people to report falling in general, but they were more likely than people aged <45 years to report falling while walking (RR=1.9, 95% CI=1.2, 3.0 for men; RR=2.2, 95% CI=1.3, 3.9 for women). Men with a low level of fitness were more likely to fall while walking than men who were highly fit (RR=2.2, 95% CI=1.5, 3.3). In the multivariate analysis, walking-related falls were associated with low levels of fitness (AOR=1.8, 95% CI=1.1, 2.8) and with physical inactivity (AOR=1.7, 95% CI=1.1, 2.7) in men but not in women. CONCLUSIONS: Falls are common throughout adulthood but activities at time of falls differ by age. Low fitness levels and physical inactivity may increase risk for walking-related falls.

Health benefits of increased walking for sedentary, generally healthy older adults: using longitudinal data to approximate an intervention trial.

Diehr P, Hirsch C.: The Journals of Gerontology. Series A, Biological sciences and medical sciences, 2010, 65(9):982-9. Department of Biostatistics, University of Washington, 1959 North East Pacific Avenue, Seattle, WA 9815-7232, USA.

BACKGROUND: Older adults are often advised to walk more, but randomized trials have not conclusively established the benefits of walking in this age group. Typical analyses based on observational data may have biased results. Here, we propose a "limited-bias," more interpretable estimate of the health benefits to sedentary healthy older adults of walking more, using longitudinal data from the Cardiovascular Health Study. METHODS: The number of city blocks walked per week, collected annually, was classified as sedentary (or=28). Analysis was restricted to persons sedentary and healthy in the first 2 years. In Year 3, some became more active (the treatment groups). Self-rated health at Year 5 (follow-up) was regressed on walking at Year 3, with additional covariates from Year 2, when all were sedentary. RESULTS: At follow-up, 83.5% of those active at baseline had excellent, very good, or good self-rated health, as compared with 63.9% of the sedentary, an apparent benefit of 19.6 percentage points. After covariate adjustment, the limited-bias estimate of the benefit was 11.2 percentage points (95% confidence interval 3.7-18.6). Ten different outcome measures showed a benefit, ranging from 5 to 11 percentage points. Estimates from other study designs were smaller, less interpretable, and potentially more biased. CONCLUSIONS: In longitudinal studies where walking and health are ascertained at every wave, limited-bias estimates can provide better estimates of the benefits of walking. A surprisingly small increase in walking was associated with meaningful health benefits.

Obesity and mobility disability in the older adult.

Vincent HK, Vincent KR, Lamb K.: Obesity Reviews : an official journal of the International Association for the Study of Obesity, 2010, 11(8):568-79. Department of Orthopaedics and Rehabilitation, Division of Research, University of Florida & Shands Orthopaedics and Sports Medicine Institute, Gainesville, FL 32611, USA.

Mobility disability is becoming prevalent in the obese older population (> or = 60 years of age). We included a total of 13 cross-sectional and 15 longitudinal studies based on actual physical assessments of mobility in the obese older population in this review. We systematically examined existing evidence of which adiposity estimate best predicted mobility disability. Cross-sectional studies (82-4000 participants) showed poorer lower extremity mobility with increasing obesity severity in both men and women. All longitudinal studies (1-22 years) except for one, reported relationships between adiposity and declining mobility. While different physical tests made interpretation challenging, a consistent finding was that walking, stair climbing and chair rise ability were compromised with obesity, especially if the body mass index (BMI) exceeded 35 kg m(-2). More studies found that obese women were at an increased risk for mobility impairment than men. Existing evidence suggests that BMI and waist circumference are emerging as the more consistent predictors of the onset or worsening of mobility disability. Limited interventional evidence shows that weight loss is related with increased mobility and lower extremity function. Additional longitudinal studies are warranted that address overall body composition fat and muscle mass or change on future disability.

Can telling older adults where to look reduce falls? Evidence for a causal link between inappropriate visual sampling and suboptimal stepping performance.

Young WR, Hollands MA.: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation cérébrale, 2010, 204(1):103-13. The School of Sport and Exercise Sciences, The University of Birmingham, Edgbaston, Birmingham, UK.

Older adults at high risk of falling look away prematurely from targets they are stepping on in order to fixate future constraints in their walking path. This gaze behaviour is associated with decreased stepping accuracy and precision. The aims of the present study were to determine whether this apparently maladaptive gaze behaviour can be altered through intervention and to measure any corresponding improvements in stepping performance. Sixteen older adults, randomly placed into a control or intervention group, walked a 10-m path placing their feet into targets while their gaze direction and lower limb kinematics were measured. On average, both groups looked away from a stepping target around 100 ms prior to foot contact and the extent of early gaze transfer correlated with stepping errors. The participants returned on a separate day and repeated the experiment; however, the intervention group was instructed to maintain gaze on each target until heel contact. Following intervention, on average participants delayed gaze transfer from the first target until after heel contact and this change in behaviour resulted in a significant reduction in stepping errors. We propose that suboptimal visual sampling strategies contribute to the incidence of falls in the elderly.

Increasing the number of steps walked each day improves physical fitness in Japanese community-dwelling adults.

Okamoto N, Nakatani T, Okamoto Y, Iwamoto J, Saeki K, Kurumatani N.: International Journal of Sports Medicine, 2010, 31(4):277-82 . Nara Medical University School of Medicine, Community Health and Epidemiology, Kashihara city, Japan.

We aimed to investigate the effects of increasing the number of steps each day on physical fitness, and the change in physical fitness according to the angiotensin-converting enzyme (ACE) genotype. A total of 174 participants were randomly assigned to two groups. Subjects in group A were instructed for 24-week trial to increase the number of steps walked each day, while subjects in group B were instructed to engage in brisk walking, at a target heart rate, for 20 min or more a day on two or more days a week. The values of the 3-min shuttle stamina walk test (SSWT) and the 30-s chair-stand test (CS-30) significantly increased, but no differences in increase were found between the groups. A significant relationship was found between the percentage increase in SSWT values and the increase in the number of steps walked by 1 500 steps or more per day over their baseline values. Our Results suggest that increasing the number of steps walked daily improves physical fitness. No significant relationships were observed between the change in physical fitness and ACE genotypes.

Community-based interventions to reduce falls among older adults in Taiwan - long time follow-up randomised controlled study.

Huang HC, Liu CY, Huang YT, Kernohan WG.: Journal of Clinical Nursing, 2010, 19(7-8):959-68. Nursing Department, National Taipei College of Nursing, Taipei, Taiwan.

Aims: The aim of the study was to examine the effects of different interventions that are used to prevent falls. These were education, Tai Chi Chuan and education plus Tai Chi Chuan; the study involved a five-month implantation period and a one-year follow-up period. Background: With advancing years, a fall can be very serious and an increased number of falls/re-falls among older adults has been noted. Hence, both education about risk factors and balance exercise programs such as Tai Chi Chuan may help to prevent falls. Design: This study adopted a randomised case-controlled design with a two-by-two factorial approach. It included three intervention groups and one control group in a community-based program. Methods: Cluster-randomised sampling was used and four villages in Taiwan City were selected. Three interventions groups and one control group were involved over five-months from late July 2000-January 2001 and each participant was followed up one year later (n = 163). Results: The intervention involving education plus Tai Chi Chuan resulted in a statistically significant reduction in falls and the risk factors of falls over the five-month intervention. After one-year follow-up, participants receiving any one of the interventions showed a reduction in falls compared with the control group. Conclusions: Tai Chi Chuan was able to improve gait balance significantly. Education may also help participants to prevent falls-by eliminating related risk factors present in their environment. However, it was found that at the one-year follow-up, any one of the three interventions had reduced falls significantly. Relevance to clinical practice:: The prevention of falls among older adults seems to needs multiple interventions. Education plus Tai Chi Chuan has both an immediately and a long-term effect and it is possible that a shorter intervention period using this approach would also be successful.

Walking and ageing

Mourey F.: Soins. Gérontologie, 2010, (83):20-2. Université de Bourgogne, Gérontopôle, Centre gériatrique de Champmaillot, CHU de Dijon.

As we get older, our gait changes insidiously with a tendency for us to walk more slowly, to take shorter strides and to increase the time when both feet are on the ground. Four major factors are most often found interlinked in walking problems in the elderly. Being more aware of them enables healthcare teams to adapt the care provided to elderly patients.

Effects of a physical training programme on cognitive function and walking efficiency in elderly persons with dementia.

Kemoun G, Thibaud M, Roumagne N, Carette P, Albinet C, Toussaint L, Paccalin M, Dugué B.: Dementia and Geriatric Cognitive Disorders, 2010, 29(2):109-14. Department of Physical Medicine and Rehabilitation, University Hospital of Poitiers, Poitiers, France.

OBJECTIVES: To study the effects of physical stimulation based on walking exercises, equilibrium and endurance on cognitive function and walking efficiency in patients with dementia. METHODS: Randomized controlled trial including 31 subjects suffering from dementia (age: 81.8 +/- 5.3 years). The intervention group (n = 16) benefited from a 15-week physical activity programme involving three 1-hour sessions per week. The control group (n = 15) did not practice any physical activities. Before and after rehabilitation, all subjects were evaluated with the Rapid Evaluation of Cognitive Functions test (ERFC French version) and walking analysis. RESULTS: After the 15 weeks of rehabilitation, the subjects from the intervention group improved their overall ERFC score (p < 0.01), while those in the control group decreased their overall ERFC score. Interactions were also observed between walking parameters and groups (p < 0.01); the intervention group improved walking capacities through heightened walking speed, stride length and a reduction in double limb support time. Lastly, the subjects from the control group presented a reduction in both walking speed and stride length. CONCLUSION: This study shows that a physical activity programme can slow cognitive decline and improve quality of walking in elderly persons suffering from dementia.

Time course and mechanisms of adaptations in cardiorespiratory fitness with endurance training in older and young men.

Murias JM, Kowalchuk JM, Paterson DH.: Journal of Applied Physiology (Bethesda, Md. : 1985)

201003 108(3):621-7. Canadian Centre for Activity and Aging, School of Kinesiology, The University of Western Ontario, London, Ontario, Canada.

The time-course and mechanisms of adaptation of cardiorespiratory fitness were examined in 8 older (O) (68 +/- 7 yr old) and 8 young (Y) (23 +/- 5 yr old) men pretraining and at 3, 6, 9, and 12 wk of training. Training was performed on a cycle ergometer three times per week for 45 min at approximately 70% of maximal oxygen uptake (Vo(2 max)). Vo(2 max) increased within 3 wk with further increases observed posttraining in both O (+31%) and Y (+18%), (P < 0.05). Maximal cardiac output (Q(max), open-circuit acetylene) and stroke volume were higher in O and Y after 3 wk with further increases after 9 wk of training (P < 0.05). Maximal arterial-venous oxygen difference (a-vO(2 diff)) was higher at weeks 3 and 6 and posttraining compared with pretraining in O and Y (P < 0.05). In O, approximately 69% of the increase in Vo(2 max) from pre- to posttraining was explained by an increased Q(max) with the remaining approximately 31% explained by a widened a-vO(2 diff). This proportion of Q and a-vO(2 diff) contributions to the increase in Vo(2 max) was consistent throughout testing in O. In Y, 56% of the pre- to posttraining increase in Vo(2 max) was attributed to a greater Q(max) and 44% to a widened a-vO(2 diff). Early adaptations (first 3 wk) mainly relied on a widened maximal a-vO(2 diff) (approximately 66%) whereas further increases in Vo(2 max) were exclusively explained by a greater Q(max). In conclusion, with short-term training O and Y significantly increased their Vo(2 max); however, the proportion of Vo(2 max) increase explained by Q(max) and maximal a-vO(2 diff) throughout training showed a different pattern by age group.

How often and how far do frail elderly people need to go outdoors to maintain functional capacity?

Shimada H, Ishizaki T, Kato M, Morimoto A, Tamate A, Uchiyama Y, Yasumura S.: Archives of Gerontology and Geriatrics, 2010 Mar-Apr 50(2):140-6. Research Team for Promoting Independence of the Elderly, Tokyo Metropolitan Institute of Gerontology, 35-2, Sakaecho, Itabashi-ku, Tokyo, 173-0015, Japan.

The Purpose of this study was to investigate the relationship between the frequency of going outdoors into the life-space and functional impairment in community-living frail elderly people. Participants were 1872 community-dwelling elderly people (65-100 years). The participants were asked activities of daily living (ADL) status and how far they traveled and how often they traveled to that area in the 4 weeks before the assessment. We selected two demographic variables, five physiological variables, 11 primary diseases or geriatric syndromes, and four psychosocial variables as possible confounding factors of ADL limitations and correlates of going outdoors. After adjusting for the confounders, multiple logistic regression showed that limitations in basic ADL and instrumental ADL were most strongly associated with going outside the home less than once a week and with going into the neighborhood less than once a week, respectively. Low self-efficacy for going outdoors related most strongly to restrictions in these outdoor activities. These results suggest that going outdoors into the neighborhood at least once a week is beneficial for maintaining physical function in frail elderly people.