Physical Activity In Older Men Research Articles

Exploring Factors Associated With Resilience and Physical Activity in Older Men and Women Post-Hip Fracture.

This study aimed to test a model of factors associated with resilience and physical activity post-hip fracture and compare model fit between men and women. We used data from the seventh Baltimore Hip Study that included 339 participants. Model testing indicated that health status (men: β = .237, p = .002; women: β = .265, p = <.001), depression (men: β = -.245, p = .001; women: β = -.241, p = <.001), and optimism (men: β = .320, p = <.001; women: β = .282, p = <.001) were associated with resilience in men and women, but resilience was only associated with physical activity in men (β = .203, p = .038) and not in women. Social interaction was related to physical activity only among women (β = .206, p = .044). This study provides support for the relationship between resilience and physical activity at least among men.

Age-gender differences in the relationships between physical and mental health

Previous studies have identified that smoking, exercise and breadth of social interaction mediate the strong associations between physical and mental health. However, these studies have been restricted to older populations, have not explored differences by gender, and have not considered online social interaction. We explore how the effects of four mediators (exercise, smoking, in-person and online social interaction) of the two-way relationships between past and future physical and mental health vary across eight age and gender groups. We use data from a representative sample of the UK population consisting of 175,779 observations on 41,995 adults from Understanding Society (UKHLS) between 2009 and 2019. Within a mediation framework, we estimate the percentage of the total effects that can be explained by the proposed mediating factors. We show that exercise, smoking, in-person and online social interaction are significant mediators of the effect of mental health on future physical health. In-person social interaction is the largest of these, accounting for 2.3% of the total effect. Smoking, in-person and online interaction are significant mediators of the effect of physical health on future mental health. Again, in-person interaction is the largest of these, accounting for 3.0% of the total effect. The percentages of the total effects mediated by each factor differ substantially by age and gender. Seeking to avoid the harmful effects of poor physical health on future mental health should focus on increasing physical activity in older men, and on increasing in-person social interaction in both men and women. Seeking to avoid the harmful effects of poor mental health on future physical health should focus on increasing physical activity and in-person social interaction in older men and women, and on reducing smoking in younger men and women.

Ten-year mortality among older male recreational endurance athletes in the Birkebeiner Aging Study in comparison with older men from the Tromsø Study.

Physical activity (PA) is associated with reduced mortality. However, whether there is an added benefit of long-term endurance training is unclear. Thus, we aimed to examine 10-year mortality in older male endurance athletes compared with an older male general population. Male athletes (n = 503) participating in an annual long-distance ski race (median years of participation: 14, range: 1-53) from the Norwegian Birkebeiner Aging study (BiAS), and non-athletic men (n = 1867) attending the sixth Tromsø Study (Tromsø6) aged ≥65 years were included. Associations with endurance sport practice and joint exposures of endurance sport practice and self-reported leisure-time PA with all-cause mortality were examined. We analyzed the data with Cox proportional hazard models and regression standardization. After 10 years (median: 10.4, range: 0.5-11.1) the mortality rate was lower in athletes (hazard ratio (HR) 0.34, 95% confidence interval (CI): 0.24-0.49) compared with non-athletes, corresponding to a 15% (95% CI: 12-19%) absolute risk reduction associated with endurance sport practice. In joint analyses categorized according to PA and endurance sport practice, we observed an inverse dose-response relationship with mortality (p < 0.001). Compared to inactive non-athletes, PA was associated with lower mortality in both active non-athletes and athletes. However, the observed benefit among participants reporting moderate-to-vigorous PA was larger in athletes (HR: 0.21, 95% CI: 0.14-0.32) than non-athletes (HR: 0.43, 95% CI: 0.31-0.59) (p < 0.01). Endurance sport practice was associated with reduced 10-year mortality, beyond the effect of PA in older men. This study suggests that long-term endurance sport practice maintained into older adulthood promotes longevity.

Motives for physical activity in older men and women: A twin study using accelerometer-measured physical activity.

Motives for physical activity may vary considerably by age, sex, and the level of physical activity. We aimed to examine motives for physical activity in older men and women with different physical activity levels as well as whether genetic and/or environmental factors explain those motives. Finnish twins (mean age 72.9years, 262 full twin pairs) self-reported their motives for physical activity. Time spent on moderate-to-vigorous physical activity was monitored using a hip-worn accelerometer. Comparisons between the different physical activity groups of older twins (n=764-791/motive dimension) were analyzed using the Wald test, and effect sizes were calculated as Cohen's d. Quantitative genetic modeling was used to estimate genetic and environmental contributions. For both sexes, the most frequently reported motives for physical activity were physical fitness, health maintenance, and psychological well-being. Conforming to others' expectations was more important for men than for women (P<.001, Cohen's d=0.38), while appearance (P=.001 Cohen's d=-0.24) and psychological well-being (P=.02, Cohen's d=-0.17) were highlighted by women. Most of the motive dimensions differed significantly between the physically active and inactive individuals. It was estimated that 5%-42% of the variation in motives was contributed by genetic factors and 58%-95% by environmental factors. The result that environmental factors contribute in a great deal to motives indicates that interventions to motivate physically inactive older individuals to be physically active can be successful. However, personalized interventions are needed because sex and the level of physical activity were found to be associated with older individuals' motives for physical activity.

Associations between social isolation, loneliness, and objective physical activity in older men and women

BackgroundThe impact of social isolation and loneliness on health risk may be mediated by a combination of direct biological processes and lifestyle factors. This study tested the hypothesis that social isolation and loneliness are associated with less objective physical activity and more sedentary behavior in older adults.MethodsWrist-mounted accelerometers were worn over 7 days by 267 community-based men (n = 136) and women (n = 131) aged 50–81 years (mean 66.01), taking part in the English Longitudinal Study of Ageing (ELSA; wave 6, 2012–13). Associations between social isolation or loneliness and objective activity were analyzed using linear regressions, with total activity counts and time spent in sedentary behavior and light and moderate/vigorous activity as the outcome variables. Social isolation and loneliness were assessed with standard questionnaires, and poor health, mobility limitations and depressive symptoms were included as covariates.ResultsTotal 24 h activity counts were lower in isolated compared with non-isolated respondents independently of gender, age, socioeconomic status, marital status, smoking, alcohol consumption, self-rated health, limiting longstanding illness, mobility limitations, depressive symptoms, and loneliness (β = − 0.130, p = 0.028). Time spent in sedentary behavior over the day and evening was greater in isolated participants (β = 0.143, p = 0.013), while light (β = − 0.143, p = 0.015) and moderate/vigorous (β = − 0.112, p = 0.051) physical activity were less frequent. Physical activity was greater on weekdays than weekend days, but associations with social isolation were similar. Loneliness was not associated with physical activity or sedentary behavior in multivariable analysis.ConclusionsThese findings suggest that greater social isolation in older men and women is related to reduced everyday objective physical activity and greater sedentary time. Differences in physical activity may contribute to the increased risk of ill-health and poor wellbeing associated with isolation.

The Relationships Between Muscle Power and Physical Activity in Older Men With Chronic Obstructive Pulmonary Disease.

The purpose of this study was to determine the potential relationship between muscle power of the lower extremities and the physical activity in older men with chronic obstructive pulmonary disease (COPD). Forty-four men (70.3 ± 6.7 years old) with moderate-to-severe COPD completed the 6-min walk test (6MWT), BODE (body mass index, obstruction, dyspnea, and exercise), a one-repetition maximum strength of the quadriceps femoris (1RMQF), and muscle power at 50% and 70% 1RMQF. Physical activity was measured using an accelerometer. The 6MWT was associated with muscle power at 50% 1RMQF (r = .40; P = .013) but not muscle power at 70% 1RMQF (r = .24; P = .15) or 1RMQF (r = .13; P = .44). Light-intensity activity was positively correlated with muscle power at 50% 1RMQF (r = .52; P = .001). Lower limb muscle power is associated with the 6MWT and light-intensity activities in older men with COPD.

Sensorimotor Peripheral Nerve Function and Physical Activity in Older Men.

We determined whether sensorimotor peripheral nerve (PN) function was associated with physical activity (PA) in older men. The Osteoporotic Fractures in Men Study Pittsburgh, PA, site (n = 328, age 78.8 ± 4.7 years) conducted PN testing, including: peroneal motor and sural sensory nerve conduction (latencies, amplitudes: CMAP and SNAP for motor and sensory amplitude, respectively), 1.4g/10g monofilament (dorsum of the great toe), and neuropathy symptoms. ANOVA and multivariate linear regression modeled PN associations with PA (Physical Activity Scale for the Elderly [PASE] and SenseWear Armband). After multivariable adjustment, better motor latency was associated with higher PASE scores (160.5 ± 4.8 vs. 135.6 ± 6.7, p < .01). Those without versus with neuropathy symptoms had higher PASE scores (157.6 ± 5.3 vs. 132.9 ± 7.1, p < .01). Better versus worse SNAP was associated with slightly more daily vigorous activity (9.5 ± 0.8 vs. 7.3 ± 0.7, p = .05). Other PN measures were not associated with PA. Certain PN measures were associated with lower PA, suggesting a potential pathway for disability.

An exploration of barriers and facilitators to older adults' participation in higher impact physical activity and bone health: a qualitative study.

SummaryThis qualitative study explored the acceptability of high-impact physical activity for increasing bone strength in later life. Thematic analysis established the barriers and facilitators to this physical activity. They prioritised joint over skeletal health, of which they had little concept. Interventions need to clearly communicate the rationale and benefits.IntroductionThe aim of this study was to explore the acceptability of doing high-impact physical activity in later life.MethodsThis qualitative study was embedded within a large-scale observational study and was designed to address specific objectives and feed into a subsequent intervention. Five focus groups with physically active men and women (over 50 years) were used to develop an interview topic guide to explore the acceptability of high-impact physical activity in older men and women (over 65 years) in South West England. A total of 28 semi-structured interviews with 31 participants were then conducted and transcripts analysed thematically.ResultsThree main barriers emerged: conceptualising bone, damage to joints and falling/safety concerns. Two main facilitators were also identified: the need to understand clear tangible benefits and incorporation of activity into everyday habits. Older adults were interested how high-impact physical activity would help to maintain their mobility, independence or social relationships. Some participants wanted tangible feedback from accelerometers, health care professionals and/or bone scans in order to develop a more intimate knowledge of their bone health.ConclusionsInterventions incorporating high-impact physical activity for older adults need to communicate how this activity can impact more broadly on health and lives; that physical activity will be safe, beneficial and not damaging to their joints will need to be clearly conveyed. Ways in which high-impact physical activity can be habitualised into everyday activities, be fun and interactive may help facilitate longer term adoption.

Worse Sensorimotor Peripheral Nerve Function is Associated with Lower Objective Physical Activity in Older Men

Sensorimotor peripheral nerve (PN) impairments are common in older adults and negatively impact mobility and lower extremity physical function. Whether worse PN is related to lower physical activity levels (PA) is unclear, though PA may be in the pathway from PN to mobility disability. PURPOSE: To determine whether worse PN function is associated with lower PA levels in older men. METHODS: In 2007–09, participants at the Pittsburgh, PA, site of the Osteoporotic Fractures in Men Study (age 78.9 ± 4.7 years) underwent sural sensory nerve (SNAP=amplitude in uV) and peroneal motor nerve (CMAP=amplitude in mV) conduction testing using a neurodiagnostic instrument. CMAP and SNAP were categorized into tertiles, with lower tertiles indicating worse PN function. Objective PA was assessed using a multisensor armband. Multivariate linear regression modeled the association between PN and minutes per day of sedentary (<1.6 METS, excluding sleep), light (1.6 to <3.0 METS), moderate (3.0 to <6.0 METS) and vigorous (6.0+ METS) activity, adjusting for demographic, lifestyle, and health factors. Proprietary algorithms estimated METS using age, smoking, and body mass index, so they were not included in the primary models, though age-adjusted sensitivity analyses were done. RESULTS: Participants (n=307) spent a median of 832, 64, 70, and 9 minutes in sedentary, light, moderate, and vigorous activity per day, respectively. After adjusting for health status and diabetes, men in the lowest tertile of CMAP participated in 16%, 17%, and 32% fewer minutes of light, moderate and vigorous activity and 4% more sedentary time compared to the middle/highest tertile (p<0.05 for all). Compared to the middle/highest tertile, men with the lowest SNAP participated in 16%, 20%, and 28% fewer minutes of light, moderate and vigorous activity, respectively (p<0.05 for all), though sedentary time did not differ. Further adjustment for age slightly attenuated associations between PN and PA, with relationships to moderate PA becoming non-significant. CONCLUSION: Worse PN is associated with less daily PA in older men, indicating a potential pathway for disability that warrants further investigation. Supported by NIH: U01 AR45580, U01 AR45614, U01 AR45632, U01 AR45647, U01 AR45654, U01 AR45583, U01 AG18197, U01 AG027810, UL1 TR000128 and T32-AG000181.

Statins and physical activity in older men: the osteoporotic fractures in men study.

Muscle pain, fatigue, and weakness are common adverse effects of statin medications and may decrease physical activity in older men. To determine whether statin use is associated with physical activity, longitudinally and cross-sectionally. Men participating in the Osteoporotic Fractures in Men Study (N = 5994), a multicenter prospective cohort study of community-living men 65 years and older, enrolled between March 2000 and April 2002. Follow-up was conducted through 2009. Statin use as determined by an inventory of medications (taken within the last 30 days). In cross-sectional analyses (n = 4137), statin use categories were users and nonusers. In longitudinal analyses (n = 3039), categories were prevalent users (baseline use and throughout the study), new users (initiated use during the study), and nonusers (never used). Self-reported physical activity at baseline and 2 follow-up visits using the Physical Activity Scale for the Elderly (PASE). At the third visit, an accelerometer measured metabolic equivalents (METs [kilocalories per kilogram per hour]) and minutes of moderate activity (METs ≥3.0), vigorous activity (METs ≥6.0), and sedentary behavior (METs ≤1.5). At baseline, 989 men (24%) were users and 3148 (76%) were nonusers. The adjusted difference in baseline PASE between users and nonusers was -5.8 points (95% CI, -10.9 to -0.7 points). A total of 3039 men met the inclusion criteria for longitudinal analysis: 727 (24%) prevalent users, 845 (28%) new users, and 1467 (48%) nonusers. PASE score declined by a mean (95% CI) of 2.5 (2.0 to 3.0) points per year for nonusers and 2.8 (2.1 to 3.5) points per year for prevalent users, a nonstatistical difference (0.3 [-0.5 to 1.0] points). For new users, annual PASE score declined at a faster rate than nonusers (difference of 0.9 [95% CI, 0.1 to 1.7] points). A total of 3071 men had adequate accelerometry data, 1542 (50%) were statin users. Statin users expended less METs (0.03 [95% CI, 0.02-0.04] METs less) and engaged in less moderate physical activity (5.4 [95% CI, 1.9-8.8] fewer minutes per day), less vigorous activity (0.6 [95% CI, 0.1-1.1] fewer minutes per day), and more sedentary behavior (7.6 [95% CI, 2.6-12.4] greater minutes per day). Statin use was associated with modestly lower physical activity among community-living men, even after accounting for medical history and other potentially confounding factors. The clinical significance of these findings deserves further investigation.

Physical activity in older men: longitudinal associations with inflammatory and hemostatic biomarkers, N-terminal pro-brain natriuretic peptide, and onset of coronary heart disease and mortality.

ObjectivesTo examine associations between habitual physical activity (PA) and changes in PA and onset of coronary heart disease (CHD) and the pathways linking PA to CHD.DesignBritish Regional Heart Study population-based cohort; men completed questionnaires in 1996 and 1998 to 2000, attended rescreen in 1998 to 2000, and were followed up to June 2010.SettingCommunity.ParticipantsOf 4,252 men recruited from primary care centers (77% of those invited and eligible) who were rescreened in 1998 to 2000, 3,320 were ambulatory and free from CHD, stroke, and heart failure and participated in the current study.MeasurementsUsual PA (regular walking and cycling, recreational activity and sport). Outcome was first fatal or nonfatal myocardial infarction.ResultsIn 3,320 ambulatory men, 303 first and 184 fatal CHD events occurred during a median of 11 years of follow-up; 9% reported no usual PA, 23% occasional PA, and 68% light or more-intense PA. PA was inversely associated with novel risk markers C-reactive protein, D-dimer, von Willebrand Factor and N-terminal pro-brain natriuretic peptide (NT-proBNP). Compared with no usual PA, hazard ratios (HRs) for CHD events, adjusted for age and region, were 0.52 (95% confidence interval (CI) = 0.34–0.79) for occasional PA, 0.47 (95% CI = 0.30–0.74) for light PA, 0.51 (95% CI = 0.32–0.82) for moderate PA, and 0.44 (95% CI = 0.29–0.65) for moderately vigorous or vigorous PA (P for linear trend = .004). Adjustment for established and novel risk markers somewhat attenuated HRs and abolished linear trends. Compared with men who remained inactive, men who maintained at least light PA had an HR for CHD events of 0.73 (95% CI = 0.53–1.02) and men whose PA level increased had an HR of 0.86 (95% CI = 0.55–1.35).ConclusionEven light PA was associated with significantly lower risk of CHD events in healthy older men, partly through inflammatory and hemostatic mechanisms and cardiac function (NT-proBNP).

Markers of oxidative stress and erythrocyte antioxidant enzyme activity in older men and women with differing physical activity

The aim of the present study was to examine the relationship between markers of oxidative stress and erythrocyte antioxidant enzyme activity and physical activity in older men and women. The present study included 481 participants (233 men and 248 women) in the age group 65–69years (127 men and 125 women) and in the age group 90years and over (106 men and 123 women). The classification of respondents by physical activity was based on answers to the question if, in the past 12months, they engaged in any pastimes which require physical activity. The systemic oxidative stress status was assessed by measuring plasma iso-PGF2α and protein carbonyl concentration as well as erythrocyte antioxidant enzymes activity, i.e., superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR). The concentration of plasma iso-PGF2α and protein carbonyls (CP) was lower in groups of younger men and women compared to the respective older groups. In all examined groups, physical activity resulted in decrease of these oxidative stress markers and simultaneously caused adaptive increase in the erythrocyte SOD activity. Additionally, in active younger men CAT, GPx, and GR activities were higher than in sedentary ones. In conclusion, oxidative stress increase is age-related, but physical activity can reduce oxidative stress markers and induce adaptive increase in the erythrocyte antioxidant enzyme activity, especially SOD, even in old and very old men and women.

Reproducibility Of The VA Physical Activity Questionnaire (VAPAQ) In An Elderly Population

Habitual physical inactivity has been associated with the development of various chronic diseases, including cardiovascular disease. Quantification of habitual physical activity is important both for health promotion efforts and for epidemiologic studies. However, quantifying lifetime physical activity is challenging due to the reliance on recall, especially in an older population. PURPOSE: The purpose of this study was to determine the one-year reproducibility of the VA Physical Activity Questionnaire (VAPAQ) in a cohort of patients with documented abdominal aortic aneurysm disease. METHODS: Subjects included 55 men (mean age 72+7 years) enrolled in AAA STOP, a randomized, prospective longitudinal trial designed to test the ability of supervised exercise training to modify abdominal aortic aneurysm biology and early disease progression. The VAPAQ is a detailed, 5-page instrument that is acquired by a15-minute interview, and was collected by an experienced interviewer at baseline and one-year later. Adulthood recreational energy expenditure was acquired from age 25 to the present (lifetime) and also as recent (activity during the last year) and expressed as kcal/week. RESULTS: The overall correlation coefficient between the two evaluations was 0.93 (p<0.001), with an overall difference of 26 kcal/week, and a typical error (SD of the differences) of 171 kcals/week (Table). CONCLUSION: The VAPAQ is a reliable and reproducible tool to quantify habitual physical activity in older men with documented cardiovascular disease.Table

Evidence for sex differences in cardiovascular aging and adaptive responses to physical activity

There are considerable data addressing sex-related differences in cardiovascular system aging and disease risk/progression. Sex differences in cardiovascular aging are evident during resting conditions, exercise, and other acute physiological challenges (e.g., orthostasis). In conjunction with these sex-related differences-or perhaps even as an underlying cause-the impact of cardiorespiratory fitness and/or physical activity on the aging cardiovascular system also appears to be sex-specific. Potential mechanisms contributing to sex-related differences in cardiovascular aging and adaptability include changes in sex hormones with age as well as sex differences in baseline fitness and the dose of activity needed to elicit cardiovascular adaptations. The purpose of the present paper is thus to review the primary research regarding sex-specific plasticity of the cardiovascular system to fitness and physical activity in older adults. Specifically, the paper will (1) briefly review known sex differences in cardiovascular aging, (2) detail emerging evidence regarding observed cardiovascular outcomes in investigations of exercise and physical activity in older men versus women, (3) explore mechanisms underlying the differing adaptations to exercise and habitual activity in men versus women, and (4) discuss implications of these findings with respect to chronic disease risk and exercise prescription.

Change in Goal Ratings as a Mediating Variable Between Self-efficacy and Physical Activity in Older Men

Few studies have examined the associations between exercise self-efficacy, goals, and physical activity over time. This study examines whether self-selected goals mediate the changes in exercise self-efficacy on physical activity over 12 months. Data are derived from 313 older men participating in the Veterans LIFE Study. Changes in exercise self-efficacy were significantly associated with changes in physical activity both directly (betas = 0.25 and 0.24, p < 0.05) and indirectly (betas = 0.24 and 0.30, p < 0.05) through changes in health-related and walking goal ratings (betas = 0.19 and 0.20, p < 0.05). Both types of goal setting continued to partially mediate the relationship between exercise self-efficacy and physical activity when covariates were added to the models. This study extends the application of social cognitive and goal-setting theories to physical activity by showing that goals partially mediate the relationship between exercise self-efficacy and physical activity over time.

Social determinants of physical exercise in older men in Jamaica.

Background:Background: Physical activity interventions have been demonstrated to improve health-related quality of life and to be of special benefit to older adults with specific chronic conditions including arthritis, hypertension, diabetes mellitus, and heart disease.Aim:This study examined the extent and social determinants of physical exercise in elderly men in Jamaica.Materials and Methods:A sample of 2,000 men 55 years of age and older was extracted from a total of 33,674 males in the parish of St. Catherine. A 132-item questionnaire was used to collect the data. A stratified random sampling technique was used to draw the sample. Descriptive statistics were used to provide background information on the sub-sample, and logistic regressions were utilized to model physical exercise.Results:Of the respondents, 55.4% indicated good health status, 51.0% lived in rural areas; 10.4% had moderate to high functional dependence and 67.3% reported that they did some form of physical exercise. Of those who indicated involvement in physical exercise (n = 1,345), 77.2% jogged, ran, and/or walked; 13.3% did aerobics; 4.7% swam; 2.0% cycled and 0.6% did push-ups or sit-ups. The variables that predicted being engaged in physical exercise were education; age of respondents; current good health status; household head; health plan; employment status, and social support.Conclusion:Most of the elderly men were engaged in some form of physical activity and had good health. Age and good health status were the most influential social determinants of physical exercise. However, effective interventions to promote physical activity in older men in Caribbean countries such as Jamaica deserve wide implementation.

Association Of Physical Performance Measures With Bone Dimensions And Volumetric Density In Older Men

Mechanical loading is hypothesized to be the primary stimulus to which bone adapts its bending strength. Various indices are used to assess mechanical loading including physical activity questionnaires, physical performance measures, and muscle cross-sectional area (CSA). PURPOSE: The purpose of these analyses was to explore whether physical activity score or leg power were associated with tibia estimates of bone strength, cortical density (vBMD), or total bone area, and whether such associations are explained by muscle CSA in older men. Methods; Peripheral quantitative computed tomography (pQCT) was used to asses total cross-sectional area (ToA, mm2), vBMD (mg/mm3) and estimated bone bending strength (SSIp) at the 66% site of the tibia and ToA, total density (ToD) and bone compressive strength (BSI = ToA * ToD2) at the 4% site of the tibia in men aged > 65 years (N = 1,171) enrolled in the Osteoporotic Fractures in Men (MrOS) study. Physical activity was assessed by questionnaire (PASE), leg power by Nottingham Power Rig, and muscle CSA from pQCT (at the 66% tibia only). Participants were categorized into quartiles of PASE or leg power. The base model was adjusted for age, race, clinic, body weight and tibial length. For leg power, participants who were unable or refused to complete the measure were excluded from the leg power analysis, but on average had the lowest bone strength measurements. RESULTS: BSI (+6.3%) and SSIp (+3.6%) were highest in the most active physically quartile compared to the least active (p<.05). At the 4% and 66% sites, higher leg power was associated with greater ToA (p-trend=.003), BSI (p-trend=0.002) and SSIp (p-trend<.001). At the 4% site, men with the greatest leg power had both greater ToA (+5.2%) and BSI (+5.3%) compared to men with the least leg power. At the 66% site, the men with the highest leg power, compared to the men with the lowest leg power, had greater SSIp (+5.3%), but similar vBMD and ToA. After further adjusting for muscle CSA, these associations were only slightly attenuated and remained significant (p <.05) for ToA (+3.8%), BSI (+4.3%) and SSIp (+3.6%). CONCLUSIONS: These data suggest that greater leg power and physical activity in older men were associated with higher estimates of bone strength at the tibia. Adjustment for muscle CSA slightly attenuated the results.

Stability and change in physical activity in old age: the role of changes in disability.

The objective was to examine whether stability and change in physical activity in older men and women are influenced by (1) changes in disability and by (2) social relations and psychological well-being. The study is based on baseline, 3 and 4.5year follow-up data on 917 older men and women. Changes in physical activity were measured through self-reported frequencies of vigorous physical activity at the three measurement points. The analyses were carried out for two outcomes-decline in physical activity versus sustained high level of physical activity (from high to low) and sustained low physical activity versus improvement in physical activity (from low to high). The main results were: older adults with onset of tiredness or continuous tiredness in daily activities during 4.5years are more likely to have a concurrent decline in their physical activities during the same period. Older adults with onset of need of help and sustained need of help are more likely to have a decline in physical activities or to sustain a low level of physical activities during the same period. The associations between the psychosocial factors and change in physical activity are attenuated by the concurrent changes in disability. The present study supports that health promotion projects should be aware that development of tiredness and continuous tiredness are strongly related to a decline in physical activity and that onset of and sustained need of help are strongly associated with both a decline in and sustained low physical activity.

Influence of age and physical activity on the primary in vivo antibody and T cell-mediated responses in men.

The aging immune system is characterized by the progressive decline in the antibody and T cell-mediated responses to antigen. Little is known, however, about the benefits of exercise in aging on the generation of a primary immune response to antigen and the subsequent antibody and memory T cell-mediated response. Most in vivo immune research to date has utilized vaccines or recall antigens to elicit an immune response. Therefore, the purpose of this experiment was to examine the association of aging and physical activity on the primary antibody and T cell response to the novel protein antigen keyhole-limpet hemocyanin (KLH). Forty-six physically active and sedentary, young (20-35 yr) and older (60-79 yr) men were recruited. Subjects were intramuscularly immunized with 100 microg of KLH, and blood samples were collected at days 0, 7, 14, 21, and 28. Samples were measured for anti-KLH IgM, IgG, IgG1, and IgG2 by ELISA. On day 21 after intramuscular KLH administration, subjects received an intradermal injection with 1 microg of KLH of inflammation recorded at 24, 48, 72, 96, and 120 h to assess anti-KLH delayed-type hypersensitivity response. There was a significant reduction in all anti-KLH measures with aging except for anti-KLH IgG2. The physically active older group had significantly higher anti-KLH IgM, IgG, IgG1, and delayed-type hypersensitivity responses, but not IgG2 compared with the sedentary older group. In conclusion, regular physical activity in older men is associated with a more robust immune response to novel antigenic challenge.

Aging, body composition, and lifestyle: the Fels Longitudinal Study

Changes in body composition in men and women occur with age, but these changes are affected by numerous covariate factors. The study examined patterns of change in body composition and determined the effects of long-term patterns of change in physical activity in older men and women and in menopausal status and estrogen use in women. Serial measures of height, weight, body mass index (BMI), total body fat (BF), percentage BF, and fat-free mass (FFM) from underwater weighing of 102 men and 108 women enrolled in the Fels Longitudinal Study were analyzed. Physical activity levels and menopausal status were included as covariates. There were significant age-related decreases in FFM and height and increases in total BF, percentage BF, weight, and BMI. Physical activity was associated with decreases in total BF, percentage BF, weight, and BMI in men and were associated with increases in FFM and decreases in total BF and percentage BF in women. Postmenopausal women had significantly higher total BF and percentage BF than did pre- and perimenopausal women. The longer the time since menopause the greater were the increases in weight, BMI, total BF, and percentage BF; however, estrogen use attenuated these increases. Low FFM can be improved by increased physical activity. The effects of an intervention program on body composition can be masked if only body weight or BMI is measured. The effects of physical activity were more profound in postmenopausal than in premenopausal women, and estrogen use had beneficial effects on body composition.