Sedentary Seniors Research Articles

Long-Term High-Level Exercise Promotes Muscle Reinnervation With Age

The histologic features of aging muscle suggest that denervation contributes to atrophy, that immobility accelerates the process, and that routine exercise may protect against loss of motor units and muscle tissue. Here, we compared muscle biopsies from sedentary and physically active seniors and found that seniors with a long history of high-level recreational activity up to the time of muscle biopsy had 1) lower loss of muscle strength versus young men (32% loss in physically active vs 51% loss in sedentary seniors); 2) fewer small angulated (denervated) myofibers; 3) a higher percentage of fiber-type groups (reinnervated muscle fibers) that were almost exclusive of the slow type; and 4) sparse normal-size muscle fibers coexpressing fast and slow myosin heavy chains, which is not compatible with exercise-driven muscle-type transformation. The biopsies from the old physically active seniors varied from sparse fiber-type groupings to almost fully transformed muscle, suggesting that coexpressing fibers appear to fill gaps. Altogether, the data show that long-term physical activity promotes reinnervation of muscle fibers and suggest that decades of high-level exercise allow the body to adapt to age-related denervation by saving otherwise lost muscle fibers through selective recruitment to slow motor units. These effects on size and structure of myofibers may delay functional decline in late aging.

Lifelong Physical Exercise Delays Age-Associated Skeletal Muscle Decline

Aging is usually accompanied by a significant reduction in muscle mass and force. To determine the relative contribution of inactivity and aging per se to this decay, we compared muscle function and structure in (a) male participants belonging to a group of well-trained seniors (average of 70 years) who exercised regularly in their previous 30 years and (b) age-matched healthy sedentary seniors with (c) active young men (average of 27 years). The results collected show that relative to their sedentary cohorts, muscle from senior sportsmen have: (a) greater maximal isometric force and function, (b) better preserved fiber morphology and ultrastructure of intracellular organelles involved in Ca(2+) handling and ATP production, (c) preserved muscle fibers size resulting from fiber rescue by reinnervation, and (d) lowered expression of genes related to autophagy and reactive oxygen species detoxification. All together, our results indicate that: (a) skeletal muscle of senior sportsmen is actually more similar to that of adults than to that of age-matched sedentaries and (b) signaling pathways controlling muscle mass and metabolism are differently modulated in senior sportsmen to guarantee maintenance of skeletal muscle structure, function, bioenergetic characteristics, and phenotype. Thus, regular physical activity is a good strategy to attenuate age-related general decay of muscle structure and function (ClinicalTrials.gov: NCT01679977).

Circulation: Heart Failure Editors’ Picks

Summary : Lifelong exercise training maintains a youthful compliance of the left ventricle (LV), whereas a year of exercise training started later in life fails to reverse LV stiffening, possibly because of accumulation of irreversible advanced glycation end products. Alagebrium is a novel drug that breaks advanced glycation end product crosslinks and improves LV stiffness in aged animals. In this study, the authors prescribed alagebrium (200 mg daily) or placebo combined with aerobic exercise training or contact control in healthy, sedentary older individuals for 1 year. The authors evaluated overall cardiac function by the use of several modalities, including invasive pressure–volume measurements, exercise testing, and cardiac MRI before and after the training. To the authors’ knowledge, this is the first study to evaluate the effects of alagebrium and exercise training in healthy aged humans. After intervention, exercise training significantly increased exercise capacity, LV mass, and LV end-diastolic volume. Conversely, alagebrium had little effect on exercise capacity or LV geometry. However, alagebrium showed a modest improvement in LV stiffness compared with placebo. This favorable effect of alagebrium on LV stiffness was most prominent in individuals with combined alagebrium and exercise training. Conclusions : Alagebrium had no effect on hemodynamics, LV geometry, or exercise capacity in healthy, previously sedentary seniors. However, it did show a modestly favorable effect on age-associated LV stiffening.1 Summary : Maximum oxygen consumption (peak VO2) and efficiency of ventilation (VE) during exercise (VE/VCO2 slope) are known to stratify adults in heart failure for 1-year survival. On the basis of adult data, a recent American Heart Association scientific statement suggested that peak VO2<50% predicted for age and sex should be considered substantial impairment in exercise performance in children with heart disease and therefore a class I indication for heart transplant listing. This single-center study examined the association of …

Reinnervation of Vastus lateralis is increased significantly in seniors (70-years old) with a lifelong history of high-level exercise

It has long been recognized that histological changes observed in aging muscle suggest that denervation contributes to muscle deterioration and that disuse accelerates the process while running activity, sustained for decades, protects against age-related loss of motor units. Here we show at the histological level that lifelong increased physical activity promotes reinnervation of muscle fibers. In muscle biopsies from 70-year old men with a lifelong history of high-level physical activity, we observed a considerable increase in fiber-type groupings (almost exclusively of the slow type) in comparison to sedentary seniors, revealing a large population of reinnervated muscle fibers in the sportsmen. Slow-type transformation by reinnervation in senior sportsmen seems to be a clinically relevant mechanism: the muscle biopsies fluctuate from those with scarce fiber-type transformation and groupings to almost fully transformed muscle, going through a process in which isolated fibers co-expressing fast and slow MHCs seems to fill the gaps. Taken together, our results suggest that, beyond the direct effects of aging on the muscle fibers, changes occurring in skeletal muscle tissue appear to be largely, although not solely, a result of sparse denervation. Our data suggest that lifelong exercise allows the body to adapt to the consequences of the age-related denervation and to preserve muscle structure and function by saving otherwise lost muscle fibers through recruitment to different, mainly slow, motor units. These beneficial effects on motoneurons and, subsequently on muscle fibers, serve to maintain size, structure and function of muscle fibers, delaying the functional decline and loss of independence that are commonly seen in late aging.

Abstract 18931: The Effect of Breaking Advanced Glycation End-Products, With or Without Exercise Training on the Cardiovascular Effects of Aging

Introduction: Sedentary aging impairs cardiovascular (CV) structure and function. Lifelong exercise training maintains youthful left ventricular (LV) and vascular structure but has little effect on relaxation. Moreover, exercise has no effect on CV structure when begun later in life, perhaps because of the accumulation of advanced glvcation end-products (AGE). Alagebrium is a crosslink breaker that improves LV compliance in older animals, especially when combined with exercise training. We hypothesised that exercise combined with Alagebrium would improve LV function in sedentary humans. Methods: This was a dual-centre double-blind placebo controlled randomized trial with a 1-year intervention. We recruited 110 healthy subjects from the Dallas, TX (n=62) and Nijmegen, Netherlands (n=48). Subjects were randomized to either: a) no exercise+placebo; b) no exercise+Alagebrium [200mg/day]; c) Exercise+placebo; and d) Exercise+Alagebrium. We measured (VO 2 max) and used 2-D echo for measurement of speckle tracking imaging (global longitudinal strain [GLS], systolic strain rate [SR], early diastolic strain rate [SR] and late diastolic strain rate [AR]). Results: Ninety-nine subjects (age 68±5yrs; 53f/46m) completed the 1-year intervention. There were no group differences at baseline for VO 2 max, GLS, SR, ER or AR. Exercise training increased VO 2 max ( P &lt;0.001) without an additive effect of drug ( P =0.79). There was no effect of drug, training, or any combination on GLS ( P values ranged from 0.24-0.57), SR ( P =0.77- 0.91), ER ( P =0.37- 0.63), AR ( P =0.09 - 0.20) [Table 1]. Conclusion: One-year of exercise training, AGE cross link inhibition or their combination does not significantly improve LV function measured by speckle tracking in previously sedentary seniors.

Cardiovascular Effects of 1 Year of Alagebrium and Endurance Exercise Training in Healthy Older Individuals

Lifelong exercise training maintains a youthful compliance of the left ventricle (LV), whereas a year of exercise training started later in life fails to reverse LV stiffening, possibly because of accumulation of irreversible advanced glycation end products. Alagebrium breaks advanced glycation end product crosslinks and improves LV stiffness in aged animals. However, it is unclear whether a strategy of exercise combined with alagebrium would improve LV stiffness in sedentary older humans. Sixty-two healthy subjects were randomized into 4 groups: sedentary+placebo; sedentary+alagebrium (200 mg/d); exercise+placebo; and exercise+alagebrium. Subjects underwent right heart catheterization to define LV pressure-volume curves; secondary functional outcomes included cardiopulmonary exercise testing and arterial compliance. A total of 57 of 62 subjects (67 ± 6 years; 37 f/20 m) completed 1 year of intervention followed by repeat measurements. Pulmonary capillary wedge pressure and LV end-diastolic volume were measured at baseline, during decreased and increased cardiac filling. LV stiffness was assessed by the slope of LV pressure-volume curve. After intervention, LV mass and end-diastolic volume increased and exercise capacity improved (by ≈8%) only in the exercise groups. Neither LV mass nor exercise capacity was affected by alagebrium. Exercise training had little impact on LV stiffness (training × time effect, P=0.46), whereas alagebrium showed a modest improvement in LV stiffness compared with placebo (medication × time effect, P=0.04). Alagebrium had no effect on hemodynamics, LV geometry, or exercise capacity in healthy, previously sedentary seniors. However, it did show a modestly favorable effect on age-associated LV stiffening. http://www.clinicaltrials.gov. Unique identifier: NCT01014572.

Aerobic interval training compensates age related decline in cardiac function

Objectives. To study the effect of aerobic interval training (AIT) on myocardial function in sedentary seniors compared to master athletes (MA) and young controls. Design. Sixteen seniors (72± 1 years, 10 men) performed AIT (4 × 4 minutes) at ∼90% of maximal heart rate three times per week for 12 weeks. Results were compared with 11 male MA (74± 2 years) and 10 young males (23±2 years). Results. Seniors had an impaired diastolic function compared to the young at rest. AIT improved resting diastolic parameters, increased E/A ratio (44%, p <0.01), early diastolic tissue Doppler velocity (e′) (11%, p <0.05) and e′ during exercise (11%, p <0.01), shortened isovolumic relaxation rate (IVRT) (13%, p <0.01). Left ventricle (LV) systolic function (S′) was unaffected at rest, whereas S′ during stress echo increased by 29% (p <0.01). Right ventricle (RV) S′ and RV fractional area change (RFAC) increased (9%, p <0.01, 12%, p =0.01, respectively), but not RV e′. MA had the highest end-diastolic volume, stroke volume, diastolic reserve and RV S′. Conclusion. AIT partly reversed the impaired age related diastolic function in healthy seniors at rest, improved LV diastolic and systolic function during exercise as well as RV S′ at rest.

Effect of exercise training on biologic vascular age in healthy seniors

Arteriosclerosis with aging leads to central arterial stiffening in humans, which could be a prime cause for increased cardiac afterload in the elderly. The purpose of the present study was to assess the effects of 1 yr of progressive exercise training on central aortic compliance and left ventricular afterload in sedentary healthy elderly volunteers. Ten healthy sedentary seniors and 11 Masters athletes (>65 yr) were recruited. The sedentary seniors underwent 1 yr of progressive exercise training so that at the end of the year, they were exercising ∼200 min/wk. Central aortic compliance was assessed by the Modelflow aortic age, which reflects the intrinsic structural components of aortic compliance. Cardiac afterload was assessed by effective arterial elastance (Ea) with its contributors of peripheral vascular resistance (PVR) and systemic arterial compliance (SAC). After exercise training, Ea, PVR, and SAC were improved in sedentary seniors and became comparable with those of Masters athletes although the Modelflow aortic age was not changed. Moreover, after exercise training, when stroke volume was restored with lower body negative pressure back to pretraining levels, the exercise training-induced improvements in Ea, PVR, and SAC were eliminated. Aortic stiffening with aging was not improved even after 1 yr of progressive endurance exercise training in the previously sedentary elderly, while left ventricular afterload was reduced. This reduced afterload after exercise training appeared to be attributable to cardiovascular functional modulation to an increase in stroke volume rather than to intrinsic structural changes in the arterial wall.

Comparison of the Heart Function Adaptation in Trained and Sedentary Men After 50 and Before 35 Years of Age

The effects of aging and of sustained athletic activity on the heart in men aged >50 years are unknown. The aim of this study was to assess the adaptation of the heart in athletic and sedentary men aged <35 and ≥50 years. Echocardiograms recorded at rest and during submaximal exercise were analyzed in 59 athletic seniors (S(ATH) group) and 16 sedentary seniors (S(SED) group) (age ≥50 years) and in 18 athletic youth (Y(ATH) group) and 27 sedentary youth (Y(SED) group) (age <35 years). All subjects were healthy. The reproducibility of measurements was examined, and the echocardiographic characteristics were compared among the study groups. No differences were found in baseline characteristics between the Y(ATH) and Y(SED) groups and between the S(ATH) and S(SED) groups, except for their exercise routines, consisting of >8 hours of bicycling per week in the athletic groups. Left ventricular mass was greater in the Y(ATH) than in the S(ATH) group (p <0.01) and greater in the S(ATH) than in the S(SED) group (p <0.001). Likewise, left ventricular volumes were greater in the athletic than in the sedentary groups (p <0.05), although they were smaller in the seniors than in youth (p <0.01). Left ventricular stroke volume was greater in the athletic than in the sedentary groups (p <0.001); global longitudinal strain during exercise was -20.0 ± 2.4% in the S(ATH) group and -22.1 ± 2.1% in the Y(ATH) group, compared to -19.2 ± 3.4% in the S(SED) group and -20.2 ± 2.4% in the Y(SED) group (p <0.05, athletic vs sedentary). The e' velocities recorded at the septal and lateral mitral annulus were higher at rest and during exercise (p <0.01) in the youth than in the senior groups. In conclusion, systolic and diastolic myocardial adaptation to regular exercise was significantly more prominent in young than in senior volunteers.

Impact of Aging and Life‐long Exercise on Cerebral Vasomotor Reactivity

This study investigated the impact of aging and life-long aerobic exercise training on cerebral vasomotor reactivity to changes in end-tidal CO2. We used transcranial Doppler to measure cerebral blood flow velocity (CBFV) in response to hypocapnia and hypercapnia induced by hyperventilation and CO2 rebreathing method. Eleven sedentary healthy young (SY, 27 ± 5 yr, 5 women), 10 sedentary seniors (SS, 72 ± 4 yr, 3 women) and 10 Masters Athletes (MA, 72 ± 6 yr, 1 woman) participated in this study. Compared with SY, resting CBFV was reduced and cerebrovascular resistance was increased in both SS and MA (P < 0.05). The relative changes in CBFV (%) in response to hypercapnia were greater in SS and MA than in SY (79 ± 21, 96 ± 23 vs. 56 ± 11 %, P < 0.01), but the absolute increases in CBFV were similar among 3 groups ( 39 ± 19, 41 ± 17 vs. 35 ± 8 cm/s, P > 0.2). During hypocapnia, both relative and absolute decreases in CBFV were less in SS and MA than in SY (P < 0.05). These decreases also were less in MA than in SS (P < 0.05). The cerebral vasomotor reactivity, in the sedentary and physically active elderly, was preserved or enhanced to hypercapnia, but reduced to hypocapnia. It suggests that there are probably defense mechanisms against chronic cerebrovascular constriction in the elderly which improve cerebral perfusion efficiently in hypercapnia and keep the brain of hypoperfusion in hypocapnia. This study was supported by R01HL102457-01.

Estudo de associação entre nível de atividade física, risco cardiovascular e o polimorfismo do gene da apolipoproteína e em idosos

INTRODUÇÃO: com o envelhecimento, ocorre perda gradual do volume da massa muscular, responsável por quase toda a perda da força nos idosos. Estudos têm mostrado que a atividade física pode diminuir a morbidade por doenças cardiovasculares, acidente vascular cerebral e aumentar a autonomia e independência. OBJETIVO: analisar a associação entre nível de atividade física, risco cardiovascular e o polimorfismo do gene da Apolipoproteína E em idosos. MÉTODOS: estudo retrospectivo, observacional a partir de um banco de dados de base populacional onde foram selecionados idosos sedentários e com histórico de atividade física regular que eram portadores e não portadores do alelo e4 do gene da apolipoproteína E. Foram aplicados os seguintes questionários: (a) International Physical Activity Questionnaire (IPAC); (b) recordatório 24 horas e miniquestionário de frequência alimentar; (c) análises bioquímicas do perfil lipídico e glicêmico. RESULTADOS: 255 idosos foram investigados; destes, 51 (20%) eram homens e 204, mulheres (80%). A idade média da amostra foi de 67,8±5.9 anos de idade (mínimo 60 máximo 86 anos). A frequência dos alelos foi de: alelo e3 =0.78, e4=0.16 e e2=0.06; 45 idosos (17.6%) possuíam pelo menos um alelo e4 e eram sedentários, 31 (12.2%) possuíam pelo menos um alelo e4 e apresentava atividade física regular (ativa), 50 (19.6%) foram classificados como tendo os demais alelos da apoE (e2/e3) e ativos enquanto 129 (60.6%) eram e2/e3 e sedentários. CONCLUSÃO: a atividade física poderia ser um fator importante na atenuação dos efeitos genéticos negativos associados ao alelo e4 do polimorfismo da apoE.

Cardiovascular Effects of 1 Year of Progressive and Vigorous Exercise Training in Previously Sedentary Individuals Older Than 65 Years of Age

Healthy but sedentary aging leads to cardiovascular stiffening, whereas life-long endurance training preserves left ventricular (LV) compliance. However, it is unknown whether exercise training started later in life can reverse the effects of sedentary behavior on the heart. Twelve sedentary seniors and 12 Masters athletes were thoroughly screened for comorbidities. Subjects underwent invasive hemodynamic measurements with pulmonary artery catheterization to define Starling and LV pressure-volume curves; secondary functional outcomes included Doppler echocardiography, magnetic resonance imaging assessment of cardiac morphology, arterial stiffness (total aortic compliance and arterial elastance), and maximal exercise testing. Nine of 12 sedentary seniors (70.6±3 years; 6 male, 3 female) completed 1 year of endurance training followed by repeat measurements. Pulmonary capillary wedge pressures and LV end-diastolic volumes were measured at baseline, during decreased cardiac filling with lower-body negative pressure, and increased filling with saline infusion. LV compliance was assessed by the slope of the pressure-volume curve. Before training, Vo(2)max, LV mass, LV end-diastolic volume, and stroke volume were significantly smaller and the LV was less compliant in sedentary seniors than Masters athletes. One year of exercise training had little effect on cardiac compliance. However, it reduced arterial elastance and improved Vo(2)max by 19% (22.8±3.4 versus 27.2±4.3 mL/kg/mL; P<0.001). LV mass increased (10%, 64.5±7.9 versus 71.2±12.3 g/m(2); P=0.037) with no change in the mass-volume ratio. Although 1 year of vigorous exercise training did not appear to favorably reverse cardiac stiffening in sedentary seniors, it nonetheless induced physiological LV remodeling and imparted favorable effects on arterial function and aerobic exercise capacity.

Effect of Cognitive Remediation on Gait in Sedentary Seniors

Attention and executive functions show strong associations with slow gait and falls in seniors and have been shown to be amenable to cognitive remediation. However, cognitive remediation as a strategy to improve mobility has not been investigated. Using a randomized single-blind control design, 24 sedentary older adults (exercise less than or equal to once weekly and gait velocity <1 m/s) were randomly assigned to an 8-week computerized cognitive remediation program or wait-list. Primary outcome was change in gait velocity during normal pace and "walking while talking" conditions. We also compared the proportion of improvers (velocity change ≥4 cm/s) in each group. The 10 participants who completed cognitive remediation improved gait velocity from baseline during normal walking (68.2 ± 20.0 vs 76.5 ± 17.9 cm/s, p = .05) and walking while talking (36.7 ± 13.5 vs 56.7 ± 20.4 cm/s, p = .002). The 10 intervention participants improved gait velocity over the 8-week intervention both during normal walking (change: 8.2 ± 11.4-1.3 ± 6.8 cm/s, p = .10) and walking while talking (change: 19.9 ± 14.9-2.5 ± 20.1 cm/s, p = .05) compared with the 10 control participants. Six intervention participants were improvers on normal pace walking compared with three controls (odds ratio = 3.0, 95% confidence interval = 0.5-19.6). All 10 intervention participants improved on walking while talking compared with 3 controls (odds ratio = 3.5, 95% confidence interval = 1.5-8.0). The findings of this pilot trial are promising and suggest that cognitive remediation may improve mobility in sedentary seniors. This approach should be validated in larger scale trials.

One Year of Endurance Exercise Training Does Not Improve Left Ventricular Relaxation in Sedentary Seniors

BACKGROUND: Life-long endurance exercise training may attenuate the age-related changes in left ventricular (LV) relaxation. However, it is unclear whether endurance exercise training started later in life can improve LV relaxation in previously sedentary healthy seniors. PURPOSE: To determine the effect of one year of endurance exercise training on LV relaxation in sedentary healthy seniors. METHODS: Nine well-screened sedentary healthy seniors (71±3 years) who were not taking any cardiovascular medications and had no provocable ischemia during exercise were enrolled into the study. Pulmonary capillary wedge pressure (PCWP) and echocardiographic LV diastolic variables were measured at supine rest. Global LV diastolic function was assessed by the ratio of early-to-late mitral inflow velocity (E/A ratio), while LV relaxation was assessed by tissue Doppler velocities of the septal and lateral mitral annulus (Em), isovolumic relaxation time (IVRT) and color M-mode propagation velocity (Vp). LV filling pressure was assessed by PCWP. All subjects completed the one year of training, which increased maximal aerobic power (VO2 max) by ∼19% (22.8±3.4 vs. 27.2±4.3 ml/kg/min, p<0.001). Measurements were repeated after one year of exercise training. RESULTS: Heart rate was decreased (59±8 vs. 55±11 beats/min, p=0.003), while systolic (p=0.30) and diastolic blood pressure (p=0.57) were unaffected by exercise training The E/A ratio was increased after training (0.81±0.16 vs. 0.99±0.25, p=0.022). Em was decreased (9.8±1.8 vs. 8.3 ±1.0 cm/s, p=0.006), while Vp was unaffected by training (34.3±8.3 vs. 33.5±9.3, p=0.75). In contrast, IVRT was shortened after training (145±17 vs.114±11 ms, p=0.012). There was a small training-related increase in PCWP (11.4±1.7 vs. 12.5±2.8 mmHg, p=0.26). CONCLUSIONS: These results suggest that one year of exercise training does not improve LV relaxation assessed by Em or Vp in previously sedentary seniors. The effect of training on IVRT likely reflects the small increase in left atrial pressure as measured from PCWP. Based on Em and Vp, the increased E/A ratio after exercise training is more likely due to changes in driving pressure, but not likely due to improved LV relaxation.

Effects Of "Life-long" Exercise Training On Arterial Stiffness In The Elderly

BACKGROUND: It is well known that human arteries become stiffer with sedentary aging. Conversely, studies by us and others have revealed that Masters athletes (Age>65) who have been training 6-7 sessions/wk throughout their adults lives maintain youthful aortic compliance. Although previous findings support the beneficial effects of exercise training on arterial compliance in the elderly, it is still unknown how lower doses of "life-long" exercise training ameliorate arterial compliance. METHODS: We recruited senior adults (Age>65) with different life-long exercise doses from the Aerobic Center Longitudinal Study, in which patterns of physical activity have been measured for >25 yrs; 1) sedentary seniors (Q1: no regular exercise, N=7), 2) mild-active seniors (Q2: Exercise; 2-3 times/wk, N=3), 3) moderate-active seniors (Q3: Exercise; 4-5 times/wk, N=7), and 4) Masters athletes (Q4: Exercise; 6-7 times/wk, N=13). Central aortic and peripheral arterial compliance were estimated by central (carotid-femoral) and peripheral (carotid-radial) pulse wave velocity (PWV), respectively. Common carotid arterial compliance was estimated by cross-sectional area changes of systolic and diastolic phases (Sono-CT), and corresponding systolic and diastolic blood pressures with beta-stiffness index. RESULTS: Central PWV was significantly slower in seniors who trained 2-3, 4-5 or 6-7 times per week (Q2, Q3, and Q4) than in sedentary seniors (Q1), indicating that even 2-3 times per week exercise training has beneficial effects on aortic compliance. Interestingly, central PWV was not significantly different among Q2, Q3 and Q4, suggesting that this beneficial effect could plateau at small doses of exercise training. Similarly, the beta stiffness index of the common carotid artery was lower (more compliant) in Q2, Q3, and Q4 than in Q1, and was not different among Q2, Q3 and Q4. Peripheral PWV was not significantly different among all groups, suggesting limited effects of exercise training on upper limb peripheral arterial compliance. CONCLUSIONS: It appears that 2-3 times per week of "life-long" regular exercise training provides similar beneficial effects on arterial compliance as more vigorous exercise regimens. Supported by the NIH grant AG17479-05 and the NSBRI Postdoctoral Fellowship grant PR01101.

Outdoor Recreational Exercise Programs and functional capacity: a Study of Sedentary Seniors

Outdoor Recreational Exercise Programs and functional capacity: a Study of Sedentary Seniors

The Effects of Aging and Physical Activity on Doppler Measures of Diastolic Function

Healthy aging results in changes in Doppler measures of diastolic function. It is unclear whether these alterations are a specific manifestation of the aging process or reflect a cardiac adaptation to a more sedentary lifestyle. It was hypothesized that healthy, but sedentary, aging would result in slowing of diastolic filling and myocardial relaxation, whereas lifelong endurance training would prevent such changes. Doppler data were measured in young subjects and sedentary and fit seniors across a broad range of loading conditions. Thirteen sedentary healthy (70+/-4 years) and 12 fit Masters athlete (68+/-3 years) seniors were recruited. Twelve young healthy (32+/-9 years) subjects were used for comparison. Pulmonary capillary wedge pressure and Doppler variables were measured at the 6 loading conditions of baseline (twice), -15 and -30 mm Hg lower body negative pressure, and 2 levels of saline solution infusion. Doppler variables consisted of early and late mitral inflow velocity (E/A) ratio, isovolumetric relaxation time (IVRT), tissue Doppler velocities (TDI Emean), and propagation velocity of mitral inflow. Aging resulted in a decrease in E/A ratio (p<0.001), TDI Emean (p<0.001), and propagation velocity of mitral inflow (p<0.001) and an increase in IVRT (p=0.001). Lifelong endurance training did not completely prevent the changes in E/A ratio (p=0.212), IVRT (p=0.546), or propagation velocity of mitral inflow (p=1.00). Fit seniors were able to achieve E/A ratios of 1.0 during baseline and saline solution infusion. TDI Emean was higher in fit versus sedentary seniors at baseline (p=0.012) and during maximal lower body negative pressure (p=0.036), but not during saline solution infusion (p=0.493). In conclusion, age-associated abnormalities in Doppler measures of myocardial filling and relaxation are only partially minimized by lifelong endurance training and therefore may be more specific to the aging process than secondary to years of deconditioning.

The Influence of Stroke Volume in Regulating the Cardiac Output Response to Exercise

Cardiac output (Q) is exquisitely, precisely regulated. While there is no difference in the Qc response to exercise between athletes and non-athletes, there is a dramatic difference in heart rate (HR) response. We hypothesized that HR adjusts to maintain a normal Q response to exercise in response to differences in stroke volume (S V). PURPOSE: To examine the HR response to exercise in seniors with a change in SV induced by short term (1 yr) and long term (life long) endurance training. METHODS: We studied 12 master endurance athletes (6 men and 6 women, ages 65–80); and 10 (6 men and 4 women, age 65–77 yr), sedentary seniors before and after an endurance training program. The imposed training volume progressively increased to four 40min, base training sessions/week, one interval and recovery session/ week including two 30min, higher intensity (threshold) sessions/month. Q (CH rebreathing) and HR (ECG) were measured at rest, two sub maximal steady state (SS1 and SS2) and peak workloads during a maximal exercise test on a treadmill. SV was calculated as SV = Qc /HR. RESULTS: (see table): The master athletes had greater SVs than their pre training sedentary counterparts at all absolute workloads and lower HRs as expected. SV increased and HR decreased after training in the sedentary subjects, though these differences were less robust than the cross-sectional comparisons. In contrast to the response to absolute work, the change in HR for a given relative work rate (% VO max, reflecting cardiovascular control) among the groups was superimposable leading to identical increases in Qc.TableCONCLUSION: An increase in SV accompanied by a balanced decrease in HR is a central adaptive response to exercise training. Thus regardless of training status (which determines SV), HR is regulated appropriately to maintain systemic blood flow to match metabolic demand for oxygen.

Ventricular‐Arterial Coupling Deteriorates with Sedentary Aging but is Restored by Endurance Training in Healthy Seniors

We tested the hypotheses that dynamic properties of ventricular-arterial coupling deteriorate with healthy but sedentary aging and that endurance training preserve it in seniors. In 9 healthy sedentary seniors (71±3 yrs, mean±SD), 12 age-matched Masters athletes (68±3 yrs), and 9 young healthy controls (30±7 yrs), transfer function gain (Gain) between beat-to-beat changes in pulmonary artery diastolic pressure (Swan-Ganz catheter, approximating LV end-diastolic pressure, LVEDP) and systemic arterial systolic pressure (SBP, Finapres) were estimated during 6 min fixed rate (0.2 Hz) respiration to evaluate the transmission properties of changes in the LVEDP to the SBP. In addition, the transmission properties were determined after completion of 1-year endurance training (70–95% HRmax, 25–60 min/day, 3–6 days/wk) in the seniors. At baseline, Gain at high frequency (0.15–0.25 Hz) was decreased with age but preserved by chronic endurance training (Seniors, 0.7±0.3; Masters, 1.1±0.8, Young, 1.2±0.3 mmHg/mmHg). Moreover, 1-year training in the seniors normalized Gain (1.3±0.8 mmHg/mmHg). Thus, dynamic ventricular-arterial coupling deteriorates with sedentary aging but is preserved and restored by endurance training. We speculate that with healthy but sedentary aging, ventricular and vascular stiffening results in impaired ventricular-arterial coupling, while exercise training normalizes these abnormalities of the circulation.

Depression, anxiety and quality of life scores in seniors after an endurance exercise program

Mood disorders are a frequent problem in old age, and their symptoms constitute an important public health issue. These alterations affect the quality of life mainly by restricting social life. The participation in a regular exercise program is an effective way of reducing or preventing the functional decline associated with aging. The aim of the present study was to examine the effects of fitness-endurance activity (at the intensity of Ventilatory Threshold 1 (VT-1)) in depression, anxiety and quality of life scores in seniors. The study involved 46 sedentary seniors aged 60-75 (66.97 +/- 4.80) who were randomly allocated to two groups: 1) Control group, which was neither asked to vary their everyday activities nor to join a regular physical fitness program; and 2) Experimental group, whose members took part in an aerobic fitness program consisting of ergometer cycle sessions 3 times a week on alternate days for six months working at a heart rate corresponding to ventilatory threshold (VT-1) intensity. Subjects were submitted to a basal evaluation using the geriatric depression screening scale--GDS, STAI trait/state (anxiety scale) and SF-36 (quality of life scale). Comparing the groups after the study period, we found a significant decrease in depressive and anxiety scores and an improvement in the quality of life in the experimental group, but no significant changes in the control group. The data suggest that an aerobic exercise program at VT-1 intensity suffices to promote favorable modifications in depressive and anxiety scores to improve the quality of life in seniors.