Two-year trends in physical performance following supervised exercise among community-dwelling older veterans

The extent to which exercise can delay the normal decline in physical performance associated with aging is unknown. We examined the impact of 2 years of supervised exercise on cardiovascular fitness, flexibility, and strength in a group of elderly (age 65-74) veterans. Seventy-five patients exercised 3 days/week for 90-minute sessions emphasizing aerobic, flexibility, and strength development. Thirty-six (47%) completed 2 years of a voluntary supervised exercise program (n = 25 with complete data). Over a 2-year follow-up period, cardiovascular outcome variables improved significantly: metabolic equivalents increased 20% (7.4 +/- 2.2 to 9.0 +/- 2.4, P less than 0.001) and submaximal heart rate decreased 7% (68.5 +/- 8.0 to 63.6 +/- 8.4 beats/minute, P = 0.02). Resting heart rate decreased 8% (131.4 +/- 14.8 to 121.0 +/- 18.5 beats/minute, P = 0.06), but this difference did not reach statistical significance. Flexibility, measured by hamstring length, improved 11% (57.5 +/- 15.1 to 64.0 +/- 11.1 degrees, P = 0.02). Strength variables did not improve. The study indicates that improvements in cardiovascular function and flexibility achieved by the elderly in the early stages of an exercise program can be maintained for at least 2 years.

Evaluation of a supervised exercise program in a geriatric population

Most studies that assess the effects of exercise in the elderly involve subjects who are in good health. The objective of this prospective longitudinal study was to examine the impact of exercise on cardiovascular fitness, flexibility, and strength in an elderly population that included chronically ill individuals. Patients were recruited initially from a population of veterans over 64 years of age who use a VA outpatient clinic as their regular source of care. The exercise intervention consisted of 90 minutes of exercise 3 days per week at 70% of the patient's maximal capacity. Activities included stationary cycling, stretching, weight training, and walking. Of 69 patients who began the program, 49 (71%) reached 4-month follow-up. Most patients completing follow-up (76%) had at least one chronic disease, such as arthritis, hypertension, or heart disease. Patients who dropped out were more likely to have multiple chronic illnesses than those who remained in the program. Average weekly attendance was 65% and was stable over time. Improvements in cardiovascular fitness at 4-month follow-up were significant: Metabolic equivalents increased from 7.1 +/- 2.3 to 8.3 +/- 2.6 (P less than .001), treadmill time increased from 8.5 +/- 3.8 to 11.2 +/- 4.2 minutes (P less than .001), submaximal heart rate decreased from 123.7 +/- 18.8 to 118.8 +/- 19.4 beats per minute (P less than .001) and resting heart rate decreased from 68.1 +/- 10.6 to 63.3 +/- 11.6 beats per minute (P = .005).(ABSTRACT TRUNCATED AT 250 WORDS)

1,2,4-Trioxanes as potential antimalarial agents

A number of 1,2,4-trioxanes were prepared and tested for antimalarial activity in search of a simplified analogue of the naturally occurring antimalarial qinghaosu. The compounds were assayed in an in vitro system for antimalarial activity against chloroquine-susceptible and chloroquine-resistant strains of Plasmodium falciparum. The most active compounds were methyl 2-(2,4a-epidioxy-4a,5,6,7,8,8a-hexahydro-5,5,8a-trimethyl-2H-1-benzop yra n-2-yl) acetate (3b), which showed IC20's of 96 and 39 ng/mL, respectively, and 2,4a-epidioxy-3,4,4a,5,6,7,8,8a-octahydro-2-[2-(benzoyloxy)propyl]-5,5,8 a- trimethyl-2H-1-benzopyran (12), which showed IC50's of 24 and 99 ng/mL, respectively. For comparison, qinghaosu exhibits an IC50 of 1 ng/mL for both strains.

Effect of exercise on cation transport in human red cells

To test the hypothesis that environmental as well as genetic factors are important determinants of monovalent cation transport systems in humans, and to explore potential basic mechanisms of the alleged antihypertensive effects of habitual exercise, we studied the effects of a 12-week exercise program (45 minutes, 3-5 times per week) upon several membrane transport parameters in erythrocytes from a population of 63 adult men (30 normotensive subjects and 33 essential hypertensive patients). Subjects were randomly assigned into either an exercise group or a sedentary control group, and clinical and membrane transport parameters were measured at baseline and after 3 months. Exercising subjects demonstrated increases in maximal treadmill work capacity (p less than 0.001) and high-density lipoprotein cholesterol levels (p = 0.009) as well as decreases in heart rate at a fixed submaximal workload (p less than 0.05) and body weight (p less than 0.001) relative to the sedentary group. In conjunction with these well-described effects of exercise conditioning, the exercise group demonstrated a significant decrease in Na+-Li+ countertransport (p = 0.002), without significant changes in any other transport parameters measured. Blood pressure was not significantly altered in either group. We conclude that powerful environmental influences such as exercise training may act in concert with genetic factors to influence monovalent cation transport in humans and must be considered in further investigations of the pathophysiological linkage between altered monovalent cation transport and essential hypertension.