Robert H. Wood

Concurrent cardiovascular and resistance training in healthy older adults.

PURPOSE The recommendations for exercise training and physical activity for older adults include cardiovascular and resistance training components (CVT and RT, respectively). The purpose of the present investigation was to compare the fitness benefits of concurrent CVT and RT with those attained through an equivalent duration of CVT or RT alone. METHODS Thirty-six participants (ages 60-84) were assigned to a control group or to one of three exercise treatment groups. The treatment groups exercised three times per week for 12 wk using RT (N = 11), CVT (N = 10), or CVT and RT (BOTH, N = 9). Pre- and post-training, participants performed a submaximal exercise test (GXT), five repetition-maximum strength tests (5RM), and the AAHPERD functional fitness test for older adults. RESULTS All exercise treatment groups revealed lower resting heart rate and rate-pressure product; lower exercise diastolic blood pressure and rating of perceived exertion; increased GXT duration; increased leg, back, and shoulder 5RM scores; and improved AAHPERD flexibility, coordination, and cardiovascular endurance scores. The exercise treatment groups responded differently on the following: RT and BOTH enhanced arm and chest strength more than CVT; and BOTH enhanced AAHPERD strength and agility scores more than CVT or RT. CONCLUSIONS Concurrent CVT and RT is as effective in eliciting improvements in cardiovascular fitness and 5RM performance as CVT or RT, respectively. Moreover, incorporating both CVT and RT in exercise programs for older adults may be more effective in optimizing aspects of functional fitness than programs that involve only one component.

Influence of short-term endurance exercise training on heart rate variability.

PURPOSE To examine the influence of 2 wk (eight sessions) of endurance training on cardiac autonomic modulation, as measured by heart rate variability (HRV). METHODS Twenty-four males (mean age: 23.1 yr) were randomized to an exercise (EX; N = 12) or control group (CT; N = 12). EX trained for eight sessions (4x wk-1, 40 min, 80-85% HRreserve) on a cycle ergometer. ECG tracings were collected during 5 min of paced breathing (12 breaths x min-1 (PB)), 5 min of spontaneous breathing (SB1), 5 min of 70 degrees head-up tilt (TILT), and a second 5-min period of spontaneous breathing (SB2). Data were collected before (test 1), during (tests 2-4), and 48 h after (test 5) the 2-wk period. HRV was reported as the standard deviation of RR intervals, and as natural logarithm of the normalized units (NU) of high- and low-frequency power (lnHF and lnLF). RESULTS EX exhibited a significant increase in peak oxygen consumption (8%). During PB and TILT conditions, ANOVA revealed a group x time interaction such that EX exhibited lower lnLFNU and lnLF/lnHF during test 5 compared with test 1. CONCLUSION These data suggest that eight endurance exercise-training sessions performed over 2 wk enhance the relative vagal modulation of the heart during PB and TILT, but not during SB.

Social Engagement and Health in Younger, Older, and Oldest-Old Adults in the Louisiana Healthy Aging Study

Social support has been shown to influence health outcomes in later life. In this study, we focus on social engagement as an umbrella construct that covers select social behaviors in a life span sample that included oldest-old adults, a segment of the adult population for whom very little data currently exist. We examined relationships among social engagement, positive health behaviors, and physical health to provide new evidence that addresses gaps in the extant literature concerning social engagement and healthy aging in very old adults. Participants were younger (21-59 years), older (60-89 years), and oldest-old (90-97 years) adults (N = 364) in the Louisiana Healthy Aging Study (LHAS). Linear regression analyses indicated that age, gender, and hours spent outside of the house were significantly associated with self-reported health. The number of clubs and hours outside of home were more important factors in the analyses of objective health status than positive health behaviors, after considering age group and education level. These data strongly suggest that social engagement remains an important determinant of physical health into very late adulthood. The discussion focuses on practical applications of these results including social support interventions to maintain or improve late-life health.

Physical activity, mental stress, and short-term heart rate variability in patients with ischemic heart disease.

BACKGROUND Among the general population, mental stress seems to depress heart rate variability (HRV), and physical activity level seems to be positively associated with HRV. However, the extent to which these relationships exist among patients with ischemic heart disease is not clear. Therefore, this study investigated the association between level of physical activity and HRV among patients with ischemic heart disease during conditions of paced breathing and the Stroop Color-Word Conflict Test (Stroop). METHODS Forty-two patients with ischemic heart disease were assigned to groups based on their documented volume of aerobic activity: Low = 1.008-2.646 kJ/wk; Mod = 3.024-3.864 kJ/wk; and High = 4.284-7.560 kJ/wk. These groups did not differ in age, body mass index, or hostility as determined by the Minnesota Multiphasic Personality Inventory. Time and frequency domain measures of HRV were derived from electrocardiograph data obtained during 5 minutes of paced respiratory control and 5 minutes of performing the Stroop Test. RESULTS There was a main effect of activity level (P < 0.05) on the standard deviation of R-wave to R-wave intervals (SDNN), total spectral power, and high-frequency power such that these dependent variables were greater in the High group than in the Low or Mod group. Furthermore, there was a main effect of the test condition on SDNN and total power, both of which were lower during the Stroop Test as compared to paced respiratory control. CONCLUSIONS The results indicate that, among patients with ischemic heart disease, a high level of physical activity is associated with higher HRV, but is not related to stress reactivity as measured by HRV.

Physical function and quality of life in older adults: sex differences.

Objectives: Age is associated with deterioration in physical function (PF) and health-related quality of life (HRQL). Methods: We examined sex differences in the association between PF and HRQL among older adults. One hundred eight adults (ages 60 to 98 years) completed the Continuous Scale-Physical Function Performance test (CS-PFP10), Functional Status Index (FSI), and SF-36. Effects of sex and fitness group on SF-36 scores were examined by using linear and nonparametric techniques. Regression techniques were used to model HRQL indexes with CS-PFP10 and FSI scores. Results: Males had better PF as indicated by higher CS-PFP10 scores and lower FSI scores. CS-PFP scores were positively associated with several SF-36 scores in both males and females, but the strength of the association appeared greatest in males. The residual scores for the females were directly related to self-reported pain. Conclusions: These data are consistent with reports indicating that females report symptoms more often than males and rely more on feelings of discomfort during physical activity in reporting HRQL as compared with males. Thus, researchers designing interventions to enhance health-related quality of life among older adults should be aware of these potential sex differences and aim to improve actual physical functioning in males and the discomforts associated with performance of physical activities in females.

Comparison of the Validity of Four Fall-Related Psychological Measures in a Community-Based Falls Risk Screening

Abstract We examined the measurement properties of fall-related psychological instruments with a sample of 133 older adults (M age = 74.4 years, SD = 9.4). Measures included the Comprehensive Falls Risk Screening Instrument, Falls-efficacy Scale-International (FES-I), Activities-specific Balance Confidence (ABC), modified Survey of Activities and Fear of Falling in the Elderly (mSAFFE), Consequences of Falling (CoF), Physical Activity Scale for the Elderly (PASE), and 36-Item Short-Form Health Survey (SF-36). The FES-I, ABC, mSAFFE, and CoF were significantly correlated with each other, with SF-36, and with mobility. The ABC and mSAFFE were significantly correlated with PASE. The ABC differentiated between fallers and nonfallers and predicted total falls risk. Findings can assist with the selection of psychological instruments in a falls risk screening context.

Construct Validation of Physical Activity Surveys in Culturally Diverse Older Adults: A Comparison of Four Commonly Used Questionnaires

The purpose of this study was to establish validity evidence of four physical activity (PA) questionnaires in culturally diverse older adults by comparing self-report PA with performance-based physical function. Participants were 54 older adults who completed the Continuous Scale Physical Functional Performance 10-item Test (CS-PFP10), Physical Activity Scale for the Elderly (PASE), CHAMPS Physical Activity Questionnaire for Older Adults, Yale Physical Activity Survey (YPAS), and modified Baecke questionnaire. The total PASE score, three outcome scores for the CHAMPS, and three summary indices for the YPAS were significantly correlated with total CS-PFP10 score. The modified Baecke exhibited no correlations with CS-PFP10 scores. The PASE, CHAMPS, and YPAS appear to be the most valid PA self-report questionnaires for culturally diverse older adults.

Cardiovagal Autonomic Function in HIV-Infected Patients with Unsuppressed HIV Viremia

Abstract Purpose: HIV infection has been implicated in dysregulationofthe autonomic nervous system. Method: Cross-sectional study exam ining the relationship between the presence of persistent detectable HIV viral load with autonomic function, measured by heart rate variability (HRV). Non-virologic suppression (NVS) was defined as having a detectable viral load for at least 3 months prior to autonomic function testing. HRV was measured during the following 4 maneuvers: resting and paced respirations and sustained handgrip and tilt. Inferences on parasympathetic and sympathetic modulations were determined by analyzing time and frequency domains of HRV. Results: 57 participants were enrolled in 3 groups: 22 were HIV-infected participants with HIVvirologic suppression (VS; undetectable HIV viral load), 9 were HIV-infected participants who had NVS, and 26 were HIV seronegative controls. There were lower time domain parameters in the HIV-infected group as a whole compared to controls. There were no significant differences in time domain parameters among HIV-infected participants. There were no differences in frequency domain parameters during any of the maneuvers between controls and all HIV-infected participants, nor between the NVS and VS groups. Conclusion: There were differences in autonomic function between HIV-infected individuals and HIV seronegative controls, but not between the NVS and VS groups.

Influence of venous function on exercise tolerance in chronic heart failure.

PURPOSE The clinical phase of chronic heart failure (HF) includes a marked decline in exercise tolerance, in part due to impaired skeletal muscle blood flow delivery. Interestingly, the role of the venous system on exercise tolerance in patients with HF has not received much attention, despite evidence of changes in venous structure and function. The purpose of this study was to examine the relationship between forearm arterial and venous function, and exercise tolerance in patients with HF and age-matched controls. METHODS Vascular function and exercise tolerance was examined in 20 patients with HF (age 59 +/- 13 years) and 10 control subjects (age 51 +/- 16 years). Nondominant forearm arterial inflow, vascular resistance, venous capacitance, and venous outflow were evaluated at rest and after 5 minutes of upper arm occlusion, using strain gauge plethysmography. Exercise tolerance was measured as the maximum walking distance achieved on a 6-minute walking test. RESULTS Maximum walking distance (HF: 178 +/- 65 m; controls: 562 +/- 136 m, P=.0001), and forearm vascular function after occlusion were significantly different between groups (forearm arterial inflow: HF 15.3 +/- 6; controls 22 +/- 6.7; forearm venous capacitance: HF 1.4 +/- 0.5; controls 2.0 +/- 0.4; forearm venous outflow: HF 24.5 +/- 9.4; controls: 33 +/- 10 mL x 100 mL tissue(-1) x min(-1); and forearm vascular resistance: HF 7.8 +/- 3; controls 4.6 +/- 1.4 U). Correlation analysis revealed significant associations between all forearm vascular measurements after occlusion and maximum walking distance. CONCLUSION These data confirm previous studies indicating the importance of arterial reactivity on exercise tolerance in patients with HF. Additionally, the results suggest the importance of venous function as a contributing factor to exercise performance.

CD8 T-cell immune phenotype of successful aging

The nonagenarian population by definition represents individuals who have demonstrated success in aging. We determined the status of CD8(+) T-cell senescence in nonagenarians by analyzing the expression of CD28 and Fas (CD95), and analyzing activation and activation-induced cell death (AICD). Peripheral blood mononuclear cells (PBMCs) were isolated from three groups of subjects: adults (20-64-year-old), older adults (65-89-year-old), and nonagenarians (>or=90-year-old). PBMCs were stimulated with phytohemagglutinin (PHA) (10 microg/ml). The cells were labeled with conjugated antibodies specific for CD4, CD8, CD28, CD45RO, and Fas, and were analyzed by FACS((R)). There was a strong negative correlation of the percentage of CD28(+)Fas(-) CD8(+) T-cells with the age of each individual prior to stimulation in vitro (R(2)=0.76, p<0.0001). Compared to other biomarkers (CD28(-), CD28(-)CD45RO(+), and Fas(+)) that have been associated with CD8(+) T-cell aging, the loss of the CD28(+)Fas(-) CD8(+) T-cell population exhibited the strongest correlation with the individuals chronologic age. After stimulation with PHA, there was a decrease in the percentage of CD8(+) T-cells from individual >or=65-year-old that expresses both CD28(+) and Fas(+) at day 3. Surprisingly, the AICD response of CD8(+) T-cells at day 7 in the nonagenarians was higher than that in the other two groups. These results suggest that successful aging does not prevent development of the senescent phenotype of unstimulated CD8(+) T cells, but is associated with preservation of CD8 T cell functions including activation and AICD. Increased AICD may result in enhanced rejuvenation capacity of T cells and limit the impact of aging on T cell function in nonagenarians.