Biomedical subjects

Timothy S Church

Publications and source records attributed to Timothy S Church.

39 records · Page 3Linked to original sources

PubMed2002

Improvements in blood rheology after cardiac rehabilitation and exercise training in patients with coronary heart disease.

OBJECTIVES: Our purpose was to examine the effect of cardiac rehabilitation and exercise training on blood rheology in patients with coronary heart disease (CHD). Although increased blood and plasma viscosity have been associated with an increased risk of CHD, the effects of cardiac rehabilitation and exercise training on blood rheology in patients with CHD are uncertain. METHODS: We assessed whole blood effective viscosity (mu), hematocrit standardized blood viscosity (mu45)), red blood cell transport efficiency (tau(rbc)), and plasma viscosity (PV) in 23 nonsmoking patients with CHD before and after a phase II cardiac rehabilitation and exercise training program. In addition, we compared the group data with the data of a healthy reference group of 10 subjects. RESULTS: Patients with CHD had significantly elevated mu (3.35 +/- 0.35 cp vs 3.06 +/- 0.19 cp, P <.05) and mu45 (3.51 +/- 0.29 cp vs 3.12 +/- 0.06 cp, P <.001) and reduced tau(rbc) (12.7% +/- 1.0% x cp(-1) vs 14.2% +/- 0.7% x cp(-1), P <.001) compared with healthy subjects. After rehabilitation, patients with CHD had reductions in PV (1.85 +/- 0.18 cp vs 1.77 +/- 0.11 cp, P <.01) and mu45 (3.58 +/- 0.22 cp vs 3.39 +/- 0.22 cp, P <.0001) and an increase in tau(rbc) (12.4% +/- 0.8% x cp(-1) vs 13.2% +/- 0.9% x cp(-1), P <.0001). CONCLUSIONS: Cardiac rehabilitation improves blood rheology in patients with CHD by reducing mu45 and PV and elevating tau(rbc). These improvements may contribute to the increased functional capacity and reduced morbidity and mortality that is associated with participation in cardiac rehabilitation and exercise programs.

Aged↗

PubMed2002

Field testing of physiological responses associated with Nordic Walking.

This study compared the physiological responses (oxygen consumption and energy expenditure) of Nordic Walking to regular walking under field-testing conditions. Eleven women (M age = 27.1 years, SD = 6.4) and 11 men (M age = 33.8 years, SD = 9.0) walked 1,600 m with and without walking poles on a level, 200-m track. For women, Nordic Walking resulted in increased oxygen consumption (M = 14.9 ml x kg(-1) x min(-1), SD = 3.2 vs. M = 1 7.9 ml x kg(-1) min(-1), SD = 3.5; p < .001), caloric expenditure (M = 4.6 kcal x min(-1), SD = 1.2 vs. M = 5.4 kcal x min(-1), SD = 1.2; p < .001), and heart rate (M = 113.7 bpm, SD = 12.0 vs. M = 118.7 bpm, SD = 14.8; p < .05) compared to regular walking. For men, Nordic Walking resulted in increased oxygen consumption (M = 12.8 ml x kg(-1) min(-1), SD = 1.8 vs. M = 15.5, SD =3.4 ml x kg(-1) min(-1); p < .01), caloric expenditure (M = 5.7 kcal x min(-1), SD = 1.3 vs. M = 6.9 kcal x min(-1), SD = 1.8; p < .001), and heart rate (M = 101.6 bpm, SD = 12.0 bpm vs. M = 109.8 bpm, SD = 14.7; p < .01) compared to regular walking. Nordic Walking, examined in the field, results in a significant increase in oxygen use and caloric expenditure compared to regular walking, without significantly increasing perceived exertion.

Adult↗

PubMed2002

Heart rate reserve as a predictor of cardiovascular and all-cause mortality in men.

UNLABELLED: This study examined the relationship of heart rate reserve (HRR: maximal heart rate - resting heart rate) and cardiovascular disease mortality (CVD) or all-cause mortality among healthy men. METHODS: Subjects were 27,459 healthy men, age 20-59 yr, who completed a maximal treadmill exercise test and answered a health questionnaire at the baseline examination. We followed study participants from the baseline visit to the date of death or December 31, 1996, for survivors. RESULTS: Over an average follow-up of 13.0 +/- 6.2 yr, there were 724 deaths, 205 (28.3%) from CVD. For analyses, the men were stratified into two age groups: younger (20-39 yr) and older (40-59 yr). Cox regression analysis was used to adjust for age, resting heart rate, cardiorespiratory fitness (CRF), resting systolic blood pressure (SBP), SBP difference, cholesterol, triglycerides, body mass index (BMI), smoking, and alcohol consumption. Among younger men, HRR was the only factor associated with CVD mortality (instantaneous relative risk (RR) and 95% confidence interval for HRR = 0.6, 0.5-0.9 for CVD mortality by 10 beats.min(-1) increment), whereas only CRF and BMI were associated with all-cause mortality. Among older men, HRR was inversely associated with CVD and all-cause mortality, as were several other known risk factors, including CRF (RR(per 2 METs), and 95% CI for HRR = 0.7, 0.5-0.9 for CVD mortality and 0.8, 0.7-0.9 for all-cause mortality). CONCLUSIONS HRR, independent from CRF, was inversely associated with CVD mortality among men in this study. HRR may be an important exercise test parameter to predict CVD mortality in younger men, whereas CRF and other established risk factors are better predictors of CVD and all-cause mortality in older men.

Adult↗