Short-term Exercise Intervention Research Articles

EXERCISE RESULTS IN SUSTAINED IMPROVEMENT IN CARDIAC AUTONOMIC FUNCTION IN KIDNEY AND KIDNEY-PANCREAS TRANSPLANT RECIPIENTS

Due to impaired cardiac autonomic function (CAF), kidney and kidney-pancreas transplant recipients are at increased risk for sudden cardiac death. Exercise has been identified as means of improving CAF. This study evaluated the effect of a short term (4 month) exercise intervention on long-term cardiac autonomic function using 24-hour heart rate variability indices (HRV) in 14 kidney and kidney pancreas transplant recipients. At 2 months post-transplant, recipients began a 4-month exercise program prescribed at 95 percent of VANT and then either engaged in a 6-month home walking program (Ex; n = 9) or ceased exercising (QuitEx, n = 5). 24-hour measures of HRV reflecting parasympathetic (HF) and sympathetic (SDANN) modulation and circadian fluctuation (SDNN) were obtained at 2, 6 and 12 month post-transplant. Groups were similar in age, gender, race, and transplant type. Data were analyzed using repeated-measures ANOVA. The exercise intervention resulted in improved CAF which was sustained in those who quit exercising, while those who continued exercising exhibited further gains in sympathetic modulation of heart rate and circadian fluctuation with values approaching those seen in healthy controls. *p < 0.5 Within group from 2 month time point; pˆ < 0.5 Within group from 6 month time point.Table

Alterations in body weight and composition consequent to 20 wk of endurance training: the HERITAGE Family Study

Obesity is a major public health problem in the United States. The role of physical activity and formal exercise in controlling body weight has not been clearly determined. This study determined the magnitude of change in body weight and composition across sex, race, and age in response to 20 wk of endurance training. Men and women (n = 557) of various ages (16-65 y) and 2 races (black and white) exercised on cycle ergometers 3 d/wk for a total of 60 exercise sessions starting at 55% of maximal oxygen consumption (VO(2)max) for 30 min/session and building to 75% of VO(2)max for 50 min/session, where it was maintained during the last 6 wk. Skinfold-thickness measurements, circumferences, body composition (by hydrostatic weighing), and body fat distribution (by computed tomography scan at L4-L5 and the waist-hip ratio) were determined before and after training. All skinfold-thickness and circumference measures, waist-hip ratio, body mass index, total body mass, fat mass, percentage body fat, and computed tomography scan measures of total, subcutaneous, and visceral abdominal fat decreased with training, whereas total body density and fat-free mass increased. These changes were significant, but small. There were several differences in training response by sex and race, but not by age. A short-term exercise intervention can induce favorable changes in body composition, but the magnitude of these changes is of limited biological significance. Increasing physical activity likely has a major effect on body-composition and fat distribution characteristics only when it is of a greater magnitude and sustained for much longer periods

Influence of exercise adherence level on modifiable coronary heart disease risk factors and functional-fitness levels in middle-aged men.

The study investigated the potential health benefits of two levels of short-term exercise intervention, compared with non-intervention, on selected modifiable coronary heart disease (CHD) risk factors and functional fitness states in middle-aged men. All subjects underwent medical screening and signed informed consent before carrying out a standardized graded treadmill walk which required exercise up to 85% of age-predicted maximal heart rate. The results of the test were used together with musculoskeletal fitness assessments, for the prescription of a personalized exercise programme lasting 14 weeks. In all, 55 subjects were classified by adherence into high (HA, n = 20), low (LA, n = 19), or non-adherence (NA, n = 16) groups according to the degree of documented participation in the programme based on standard criteria (American College of Sports Medicine 1978, 1990). In addition, the respective groups of subjects were classified according to other modifiable and non-modifiable CHD risk factors and compared by self-reported levels of activity and sport involvement as well as perceived body weight classification. The results indicated that there were more comprehensive improvements in functional fitness including significant gains in aerobic endurance capacity, muscular endurance and flexibility in the HA group compared with the LA and NA groups. However, there was little or no change in the modifiable CHD risk factors in any of the respective groups, although anthropometric indices of weight, body mass index (BMI), skinfolds and waist:hips ratio tended to decrease in the HA and LA groups but increased marginally in the NA group.(ABSTRACT TRUNCATED AT 250 WORDS)