The relationship of exercise and diet on high-density lipoprotein cholesterol levels in women

Insulin-like growth factor-II and insulin-like growth factor binding protein-2 prospectively predict longitudinal elevation of HDL-cholesterol in type 2 diabetes

INTRODUCTION

Associations of insulin-like growth factor-II (IGF-II) and insulin-like growth factor binding protein-2 (IGFBP-2) with cardiovascular risk have been inadequately studied. We hypothesized that IGF-II and IGFBP-2 associate with longitudinal trends in lipid profiles in type 2 diabetes patients.

SUBJECTS AND METHODS

Four hundred and eighty nine subjects with type 2 diabetes (age 27-87 years) from the Salford Diabetes Cohort were studied. Longitudinal clinical information was extracted for an eight-year period (2002-2009) from an integrated electronic dataset of primary care and hospital data.

RESULTS

There were 294 male subjects and mean age was 62.9 years. At baseline, IGF-II concentration was 602 ng/mL. HDL cholesterol at baseline was associated with log-IGF-II concentration in a model adjusted for age, gender, baseline body-mass index (BMI), estimated glomerular filtration rate (eGFR) and lipid-lowering therapy. IGFBP-1 and IGFBP-2 were associated with high HDL-cholesterol. A higher circulating IGF-II concentration at baseline was also associated with longitudinal increase in HDL-cholesterol in mixed-effects regression analyses independent of IGF-I, IGFBP-1, IGFBP-2, IGFBP-3, age, gender, eGFR, BMI and lipid-lowering therapy. Log-transformed baseline concentrations of IGFBP-1 and IGFBP-2 were also associated with longitudinal elevation in HDL-cholesterol. No association was observed for IGF-II or IGFBP-2 with longitudinal LDL cholesterol trends.

CONCLUSION

Our analyses based on 'real world' data demonstrate that higher baseline IGF-II and IGFBP-2 predict increased HDL concentration over time, implicating IGF-II in modulation of circulating HDL-cholesterol concentrations.

The Effects of Exercise on Food Intake and Body Fatness: A Summary of Published Studies

Exercise has well-recognized health benefits, including reduction in risk factors for cardiovascular disease and type 2 diabetes. However, the extent to which exercise influences energy regulation and facilitates a reduction in body fat is less clear. This review summarizes published studies on the effects of different amounts of exercise on body fatness, energy intake, and food preferences in humans. The results show consistent effects of exercise on body fatness in the absence of prescribed dietary change, with a progressive loss of body fat associated with higher exercise energy expenditures in both men and women. In part, these effects appear to be mediated by a spontaneous reduction in hunger associated with participation in exercise. Insufficient data are available on whether there are changes in food preferences and taste perception that influence energy balance through macronutrient selection, so further studies in this area are needed.

Physical activity minimizes the association of body fatness with abdominal obesity in white, premenopausal women: Results from the Third National Health and Nutrition Examination Survey

This study explored the association of physical activity with body fatness and abdominal obesity in 1,004 premenopausal white women who participated in the Third National Health and Nutrition Examination Survey. Physical activity was classified into four levels based on fitness criteria from the American College of Sports Medicine. Standard protocols were used for measuring body mass index (BMI), percent body fat, and waist-to-hip ratio (WHR). Means for BMI, percent body fat, and WHR were calculated for each physical activity level. Analysis of variance procedures were performed, followed by pair-wise comparisons, to determine differences among means and for trends. Mean BMI, percent body fat, and WHR were significantly less ( P < .001) at each higher physical activity level except between Levels 0 and 1. The ability of increased daily physical activity to minimize age-related increases in abdominal obesity could be a strong incentive for women approaching menopause to become more physically active.

Blood lipid and lipoprotein adaptations to exercise: a quantitative analysis

Dose-response relationships between exercise training volume and blood lipid changes suggest that exercise can favourably alter blood lipids at low training volumes, although the effects may not be observable until certain exercise thresholds are met. The thresholds established from cross-sectional literature occur at training volumes of 24 to 32 km (15 to 20 miles) per week of brisk walking or jogging and elicit between 1200 to 2200 kcal/wk. This range of weekly energy expenditure is associated with 2 to 3 mg/dl increases in high-density lipoprotein-cholesterol (HDL-C) and triglyceride (TG) reductions of 8 to 20 mg/dl. Evidence from cross-sectional studies indicates that greater changes in HDL-C levels can be expected with additional increases in exercise training volume. HDL-C and TG changes are often observed after training regimens requiring energy expenditures similar to those characterised from cross-sectional data. Training programmes that elicit 1200 to 2200 kcal/wk in exercise are often effective at elevating HDL-C levels from 2 to 8 mg/dl, and lowering TG levels by 5 to 38 mg/dl. Exercise training seldom alters total cholesterol (TC) and low-density lipoprotein-cholesterol (LDL-C). However, this range of weekly exercise energy expenditure is also associated with TC and LDL-C reductions when they are reported. The frequency and extent to which most of these lipid changes are reported are similar in both genders, with the exception of TG. Thus, for most individuals, the positive effects of regular exercise are exerted on blood lipids at low training volumes and accrue so that noticeable differences frequently occur with weekly energy expenditures of 1200 to 2200 kcal/wk. It appears that weekly exercise caloric expenditures that meet or exceed the higher end of this range are more likely to produce the desired lipid changes. This amount of physical activity, performed at moderate intensities, is reasonable and attainable for most individuals and is within the American College of Sports Medicine's currently recommended range for healthy adults.

Relationship between physiological loss, performance decrement, and age in master athletes

BACKGROUND

The use of master athletes to describe an idealized rate of physiological loss associated with aging is quite common. The results of such studies suggest that older athletes may be able to reduce the rate of decline in functional loss. The findings of such studies have been questioned due to their limited sample size and the age range and gender of their subjects.

METHODS

We examined a group of 146 male and 82 female master athletes over the age of 40 years. Physiological parameters included maximal oxygen uptake (VO2max), body composition, muscle strength, bone density, and blood chemistries. Medical histories and training records were obtained via questionnaire.

RESULTS

Results demonstrated gender differences in body composition, blood chemistries, blood pressure, VO2max, muscle strength, bone density, and performance (p <.05). All metabolic parameters for men and most for women demonstrated significant losses across the age range (p <.05). In addition, strength and performance for men and women and bone density for women declined significantly with age (p <.05). The demonstrated loss rates did not differ by gender.

CONCLUSIONS

Although limited by the lack of a sedentary comparison group, these data suggest that age-related losses in VO2max may not be different from data previously reported for older sedentary adults and that loss in muscle strength and performance with aging is not linear.

How exercise affects lipid profiles in women: what to recommend for patients

After menopause, women have less favorable lipid profiles than before menopause. While regular exercise improves lipid metabolism in men, the specifics for doing so in pre- and postmenopausal women are not fully understood. Literature review suggests that higher-volume aerobic exercise programs increase high-density lipoprotein cholesterol (HDL-C) levels in both pre- and postmenopausal women. Although longitudinal studies of resistance training did not reveal increases in HDL-C levels in women, other favorable benefits observed included decreases in low-density lipoprotein-cholesterol, total cholesterol, and body fat. Cross-sectional studies, however, seem to favor high-volume exercise for increasing HDL-C levels.

Relation between commuting, leisure time physical activity and serum lipids in a Chinese urban population

PRIMARY OBJECTIVE

To analyse the association between both commuting and leisure time physical activity and serum lipids in a Chinese population.

POPULATION

A total of 1786 males and 1922 females aged 20-49 years.

METHODS

A cross-sectional survey was carried out in 1989 in urban area of the city of Tianjin, China. Commuting and leisure time physical activity, total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol and triglycerides were determined.

RESULTS

Daily walking or cycling to and from work was inversely associated with serum total cholesterol, low-density lipoprotein cholesterol and triglyceride concentrations among men and positively associated with high-density lipoprotein cholesterol concentrations among women as compared to travelling to and from work by bus.

CONCLUSIONS

The present study showed a significant association between serum lipids and commuting physical activity, but no relation with leisure time sports.

Exercise mitigates the association of abdominal obesity with high-density lipoprotein cholesterol in premenopausal women: results from the third National Health and Nutrition Examination Survey

OBJECTIVE

To examine the relationship between abdominal obesity, as measured by waist-to-hip ratio (WHR) and high-density lipoprotein cholesterol (HDL-C) level within the context of age, body fatness, exercise, saturated fat intake, and other plasma lipids.

DESIGN/SUBJECTS

Subjects were premenopausal, white, non-Hispanic women from the third National Health and Nutrition Examination Survey. Smokers, heavy drinkers, and women who took lipid-altering drugs were excluded. Of 1,188 subjects who met the inclusion criteria, complete data were available for 435 women.

STATISTICAL ANALYSES

Means were calculated using all subjects for each variable, then F-protected t tests and linear contrasts were performed to test differences in means between subgroups. A P < .05 was considered significant.

RESULTS

Age was not significantly associated with HDL-C level. Comparisons of HDL-C by WHR, percentage body fat (%BF), and exercise level revealed that HDL-C level was significantly lower at the higher levels of WHR and %BF and higher at the highest levels of exercise. Higher levels of HDL-C were generally accompanied by lower levels of triacylglycerol. When HDL-C was compared by exercise level within each WHR tertile and %BF tertile, the association of exercise with HDL-C diminished. Saturated fat intake was not associated with HDL-C.

CONCLUSIONS/APPLICATIONS

Increased exercise is associated with a lower WHR and subsequently a higher HDL-C level. This association between WHR and HDL-C appears to be mediated through %BF. Women exercisers with the highest WHR had consistently more favorable plasma lipid profiles and lower mean body mass index and %BF than nonexercisers. Thus, for women who exhibit abdominal obesity, exercise mitigates the association of WHR with HDL-C level. Vigorous exercise in the premenopausal years may promote a more favorable lipid profile, even in the presence of increased body fat and abdominal girth.

Physical activity and high density lipoprotein cholesterol levels: what is the relationship?

High density lipoprotein cholesterol (HDL-C) levels are strongly, inversely and independently associated with coronary heart disease (CHD). Increased physical activity is associated with reduced CHD mortality. This protection against CHD may partially be explained by the increase in HDL-C levels observed following aerobic exercise training. Many also agree that an exercise threshold needs to be met before such favourable changes in HDL-C metabolism can occur. Most likely, the exercise-induced changes in HDL-C are the result of the interaction amongst exercise intensity, frequency, duration of each exercise session and length of the exercise training period. Although a relative contribution of each exercise component (intensity, duration and frequency) is also likely, it has not been established. There is also substantial support for a dose-response relationship. Favourable changes in HDL-C appear to occur incrementally and reach statistical significance at approximately 7-10 miles per week or 1200 to 1600kcal. Exercise-induced changes in HDL-C may also be gender dependent. The volume of exercise required to increase HDL-C levels appears to be substantially more for women than men. This perhaps is due to higher HDL-C levels in women at baseline compared with men. However, the many other health benefits derived from increased physical activity should encourage women to participate in regular exercise regardless of the exercise effects on HDL-C levels. A practical approach in prescribing exercise for patients is to use moderate intensity exercises (70 to 80% of predicted maximal heart rate), 3 to 5 times per week, for a total of 7 to 14 miles per week. This is equivalent to approximately 1200 to 1600kcal per week. Moderate to low intensity exercise should be preferred because such exercise carries a lower risk for cardiac complications. In addition, patients are more likely to participate and sustain a lower than higher intensity exercise programme. It is also important to recognise that other modes of physical activity can also be encouraged for patients. Such activities should be associated with similar increases in HDL-C levels as long as they meet or exceed the caloric expenditure of 1200 to 1600kcal (7 to 14 miles per week of jogging).

Gynecologic health and disease

Traditionally the obstetrician/gynecologist has been the sole provider of health care for women. As the United States moves toward a system of greater managed care, however, family practitioners, internists, and other physician extenders (physician assistants, nurse-practitioners, and nurse-midwives) are the first-line providers for many women. These practitioners have the opportunity to influence behavioral changes and promote healthy habits by identifying risk factors and their potential consequences.

Relationship between leisure-time physical activity and selected dietary variables in the Worcester Area Trial for Counseling in Hyperlipidemia

We evaluated the relationship between Leisure-time Physical Activity (LTPA) and selected dietary variables in the Worcester Area Trial for Counseling in Hyperlipidemia. Subjects were males (N = 425) and females (N = 494) of mean age 49.8 and 48.4 yr, respectively. Dietary data were collected using a 7-d (7DDR) and a 24-h dietary recall (24HR), and LTPA information was obtained along with the 7DDR. Subjects were categorized into four levels of LTPA (0-29 (N = 548), 30-60 (N = 98), 61-120 (N = 137), and > or = 121 min.wk-1 (N = 136)). Results from ANOVA revealed that active subjects (LTPA > or = 30 min.wk-1) consumed fewer servings per week of meats, fried foods, sweets, and 2-4% milk and more servings of fruits, vegetables, low fat dairy products, and 0-1% milk than did inactive subjects (LTPA = 0-29 min.wk-1). Comparison of selected 7DDR-derived macro- and micronutrients revealed that active individuals consumed a lower fat and a more micronutrient dense diet than their more inactive counterparts. These findings were not materially altered by adjustment for age, gender, education, and smoking. Finally, the 7DDR results were confirmed in analyses of the 24HR data in a slightly smaller group of subjects (N = 756). The present findings have implications for etiologic investigations on outcomes that have both LTPA and diet as risk factors, and for targeting public health interventions.

Exercise in the prevention of atherosclerotic, metabolic and hypertensive diseases: a review

Evidence that physical inactivity and low fitness confer an increased risk of coronary heart disease (CHD) is convincing. There is a graded relationship with the amount of physical activity (or physical fitness), with some evidence that an asymptote is reached in the mid-range. Epidemiological studies have also shown that physically inactive individuals are at greater risk of developing hypertension or non-insulin-dependent diabetes or of experiencing a stroke, but less is known about the nature of these relationships. The effects of exercise on blood pressure, glucose/insulin dynamics and lipoprotein metabolism may contribute to the lower risk of these diseases in people who exercise regularly. Long-term adaptations to regular exercise may result in improved insulin sensitivity and in higher serum concentrations of high-density lipoprotein cholesterol-mediated in part by improved weight regulation. However, the residual effects of individual exercise bouts may, cumulatively, also be important; these "acute' effects may be enhanced when functional capacity is increased through training. More intensive exercise may carry greater benefits in some respects, but it also carries higher risks, for example of orthopaedic injury or triggering of heart attack. Consequently, public health policies should aim to foster a long-lasting commitment to increased levels of frequent, moderate-intensity activity in as many people as possible.

High-density lipoprotein cholesterol and other risk factors for coronary heart disease in female runners

BACKGROUND

Official guidelines from the Centers for Disease Control and Prevention assert that the majority of health benefits from physical activity are obtained by walking 2 miles (3.2 km) briskly most days of the week (the energy equivalent of running 8 to 12 km per week). The objective of our study was to examine the dose-response relation in women between risk factors for coronary heart disease, particularly the concentration of high-density lipoprotein (HDL) cholesterol, and vigorous exercise at levels that exceed the official guidelines.

METHODS

The number of kilometers run per week reported by 1837 female recreational runners in a national cross-sectional survey was compared with medical data provided by the women's physicians.

RESULTS

In these cross-sectional data, plasma HDL cholesterol concentrations were higher by an average (+/- SE) of 0.133 +/- 0.020 mg per deciliter (0.003 +/- 0.0005 mmol per liter) for every additional kilometer run per week, an amount nearly identical with that previously reported for men (0.136 +/- 0.006 mg per deciliter [0.004 +/- 0.0002 mmol per liter] per kilometer per week). Among women who ran less than 48 km per week, mean plasma HDL concentrations were significantly higher with each 16-km increment in distance. Women who ran more than 64 km per week had significantly higher mean concentrations of HDL cholesterol than did women who ran less than 48 km per week. They were also significantly more likely to have HDL cholesterol concentrations greater than 100, 90, or 80 mg per deciliter (2.6, 2.3, or 2.1 mmol per liter) than were women running less than 64 km per week. HDL cholesterol concentrations increased significantly in relation to the number of kilometers run per week in premenopausal women who were not using oral contraceptives and in postmenopausal women, whether they were receiving estrogen-replacement therapy or not.

CONCLUSIONS

Substantial increases in HDL cholesterol concentrations were found in women who exercised at levels exceeding current guidelines; higher HDL cholesterol concentrations could provide added health benefits to these women.

Effects of endurance exercise and hormone replacement therapy on serum lipids in older women

OBJECTIVE

To determine the effects of 11 months of exercise training and hormone replacement therapy (HRT), alone or in combination, on serum lipids and lipoproteins, in postmenopausal women.

DESIGN

Controlled, prospective, 11-month clinical trial. Healthy postmenopausal women (n = 71, age range 60-72 yrs) were assigned to four groups in a 2 X 2 design (control, exercise, HRT, exercise + HRT).

SETTING

Large, midwestern urban community; subjects were recruited from the community-at-large. The exercise program was conducted at a university exercise facility.

INTERVENTIONS

HRT consisted of conjugated estrogens at 0.625 mg/day and trimonthly medroxyprogesterone acetate 5 mg/day for 13 days. Exercise consisted of 2 months of low intensity exercise followed by 9 months of vigorous exercise for 45 min/day, 3 or more days/week, at 65-85% of maximal heart rate.

MEASUREMENTS

Maximal aerobic power (VO2max), resting blood pressure, body composition, serum lipids and lipoproteins, and dietary intake at baseline and after 11 months.

MAIN RESULTS

At the end of 11 months, subjects in the exercise group had decrease total cholesterol (TC; P < .01) and LDL-cholesterol (LDL-C; P < .05), but there was no change in HDL-cholesterol (HDL-C) or triglycerides. Women in the HRT group had decreased LDL-C (P < .001) and increased HDL-C (P < .01) and triglycerides (P < .01), but there was no change in TC. Exercise + HRT subjects had decreased TC (P < .05) and LDL-C (P < .001), and increased HDL-C (P < .001); exercise prevented the HRT-related increase in triglycerides.

CONCLUSIONS

Endurance exercise training and HRT have independent and complimentary effects on serum lipids profiles in healthy postmenopausal women. Such effects are likely to reduce the risk of cardiovascular morbidity in this population.

The association between cardiorespiratory fitness and prostate cancer

We conducted a prospective study to assess the association between cardiorespiratory fitness and prostate cancer. The subjects were men, aged 20-80 yr, who received a preventive medical exam at the Cooper Clinic in Dallas, TX, during 1970-1989 and provided information on cardiorespiratory fitness and prostate cancer (N = 12,975). Cardiorespiratory fitness was assessed at a baseline examination between 1971 and 1989 using a maximal exercise treadmill test. Questionnaires were mailed to the men in 1982 and 1990 to ascertain incident cases of prostate cancer. Ninety-four cases of incident prostate cancer were identified. Higher cardiorespiratory fitness levels were inversely associated with the probability of development of incident prostate cancer after controlling for age, body mass index, and smoking habits; adjusted estimates of the incidence rate ratio declined from 1.1 (95% CI 0.63-1.77) to 0.73 (95% CI 0.41-1.29) to 0.26 (95% CI 0.10-0.63) across increasing quartiles of fitness (P for trend < 0.004). This protective effect was limited to participants < 60 yr old. Also, an inverse association was observed between physical activity and prostate cancer. Compared with expending < 1000 kcal.wk-1, participants who expended 1000- < 2000, 2000- < 3000, or > or = 3000 kcal.wk-1 had adjusted incidence rate ratios of 0.37 (95% CI 0.17-0.79), 0.62 (95% CI 0.27-1.41), and 0.37 (95% CI 0.14-0.98), respectively. The results suggest that cardiorespiratory fitness and physical activity levels may protect against the development of incident prostate cancer.

Long-term (5-year) changes in HDL cholesterol in cardiac rehabilitation patients. Do sex differences exist?

BACKGROUND

It is unknown whether the benefits of a cardiac rehabilitation program on HDL cholesterol (HDL-C) are equally achieved in men and women. To study this, we compared changes in HDL-C and other lipids in a large group of men and women participating in a cardiac rehabilitation program for up to 5 years.

METHODS AND RESULTS

We compared changes in HDL-C and other fasting lipids in 553 men and 166 women participating in a cardiac rehabilitation program at baseline and then annually for up to 5 years. Patients exercised 3 days a week at 70% to 85% of their maximum heart rate predetermined by a symptom-limited treadmill test. Aerobic capacity was estimated in metabolic equivalents (METs), and percent body fat was determined by skin-fold measurements. Baseline HDL-C, LDL cholesterol (LDL-C), and total cholesterol were significantly higher in women, whereas the ratio of total cholesterol to HDL-C was lower. Although both men and women showed an increase in HDL-C after 1 year (10% and 7%, respectively), only the women's level continued to increase over 5 years (20% versus 5% for men, P = .03). The sex difference in change in HDL-C remained after adjustment for age and smoking. A nonsignificant trend toward a greater change in HDL-C in women existed after adjustment for baseline percent body fat and estimated METs. The change in the ratio of total cholesterol to HDL-C was also more favorable in women, with a 38% decrease over 5 years compared with a 14% decrease in men (P = .01). Total cholesterol decreased by 20% in women and 8% in men (P = .001), whereas LDL-C dropped by 34% in women and 15% in men (P = .0001). There was no sex difference in change in triglycerides.

CONCLUSIONS

Women with heart disease who participate in a cardiac rehabilitation program may achieve greater lipid benefits over longer periods of time than previously demonstrated in men.

Cardiorespiratory fitness and coronary heart disease risk factor association in women

OBJECTIVES

The purpose of this study was to examine the association between cardiorespiratory fitness and coronary risk factors in healthy, nonsmoking adult women.

BACKGROUND

A sedentary life-style is recognized as an independent risk factor for coronary heart disease, and increasing physical activity is strongly recommended to reduce this risk. However, studies examining the effects of increased physical activity on coronary heart disease risk factors in women are relatively few, and the findings have been equivocal.

METHODS

Subjects provided written informed consent, completed a questionnaire on medical history and performed an exercise tolerance test. Blood chemistry and lipid levels were determined from fasting blood samples. Three fitness categories were established on the basis of treadmill time to exhaustion and were adjusted for age.

RESULTS

The women in the lowest fitness category had less favorable lipid profiles, blood glucose levels, blood pressures and anthropometric indexes than those in the moderate and high fitness categories.

CONCLUSIONS

Moderate fitness (equivalent to 10 metabolic equivalents [METs]) is required to improve the coronary risk profile in women.

Hemostatic, metabolic, and androgenic risk factors for coronary heart disease in physically active and less active postmenopausal women

Physically active postmenopausal women have a lower incidence of coronary heart disease (CHD) than their more sedentary peers, but little information is available concerning the responsible mechanisms. The primary aim of this study was to test the hypothesis that physically active post-menopausal women demonstrate more favorable levels of hemostatic, metabolic, and androgenic CHD risk factors than less active control subjects. If so, a secondary aim was to determine which of the characteristics associated with a physically active lifestyle, ie, low body fat, a high-carbohydrate/low-fat diet, high maximal aerobic capacity (aerobic fitness), and high levels of physical activity, are most closely related to this lower risk profile. To address these aims, we compared CHD risk factors in physically very active women (n = 14; age, 55 +/- 2 years) with those in healthy, nonobese sedentary control subjects (n = 17; age, 56 +/- 1 years). Maximal aerobic capacity (fitness) was 83% higher (P < .001) in the physically active women. Concentrations of plasminogen activator inhibitor type 1 activity and tissue plasminogen activator antigen were lower (more favorable) (P < .005) in the physically active women versus control subjects, whereas plasma fibrinogen levels did not differ. The physically active women had lower (P < .01) fasting plasma insulin and glucose concentrations as well as smaller responses to an oral glucose challenge. Both total-body and abdominal fat levels were lower (P < .001) and lipid and lipoprotein profiles were generally more favorable (P < .05) in the physically active women.(ABSTRACT TRUNCATED AT 250 WORDS)

Brisk walking and serum lipid and lipoprotein variables in previously sedentary women--effect of 12 weeks of regular brisk walking followed by 12 weeks of detraining

The purpose of this study was to examine the effectiveness of brisk walking as a means of improving endurance fitness and influencing serum lipid and lipoprotein variables in previously sedentary women. Walkers (n = 10, mean (s.e.m.) age 47.3(2.0) years) followed a programme of brisk walking (mean(s.e.m.) speed 1.76(0.03) m s-1) for 12 weeks, after which the training stimulus was withdrawn. Controls (n = 10, mean(s.e.m.) age 41.6(1.2) years) maintained their habitual sedentary lifestyle throughout. Endurance fitness was determined using laboratory measures of responses to treadmill walking. Serum lipid and lipoprotein variables were determined in venous blood (12-h fasted). Body fatness was assessed by anthropometry and dietary practice using the 7-day weighed food intake technique. Measurements were repeated after 12 and 24 weeks. Brisk walking resulted in a decrease in heart rate and blood lactate concentration during exercise, while detraining was accompanied by a reversal of these changes. Changes in body mass and the ratio of circumferences at the waist and hip did not differ between groups but the sum of four skinfolds decreased with brisk walking and increased with detraining. High density lipoprotein (HDL) and HDL2 cholesterol increased with walking and decreased with detraining but no between group changes (analysis of variance, P < 0.05) were found in other lipid and lipoprotein variables. These findings suggest that regular brisk walking can improve endurance fitness and increase HDL cholesterol concentration in sedentary women.

Exercise training and nutrient intake in elderly women

This study examined the relationship between moderate exercise training (five 30- to 40-minute sessions per week for 12 weeks at 60% of heart rate reserve) and changes in nutrient intake in a group of 30 sedentary elderly women aged 67 to 85 years. Subjects were placed randomly into two groups (those who walked and those who did calisthenics) and were followed for 12 weeks. Measurements were done at three times (baseline, 5 weeks, and 12 weeks). Dietary intake was based on 7-day food records. The 12-week walking program resulted in a significant (12.6%) improvement in maximum oxygen consumption (VO2max) but no change in body weight or skinfold thicknesses compared with the calisthenics program. Despite the improvement in cardiorespiratory fitness, no significant group x time interaction effects were observed for most of the nutrient intake variables tested. To test the effects of high levels of physical activity on nutrient intake, cross-sectional comparisons were made at baseline between highly conditioned and sedentary elderly women. The highly conditioned elderly women had higher energy and nutrient intakes, especially when expressed on a weight-adjusted basis. However, no differences in measures of dietary quality were found. Dietitians should not expect spontaneous improvement in either the quantity or quality of nutrient intake by elderly women who adopt a moderate exercise program. Although nutrient intake was greater in highly conditioned elderly women, their level of fitness and physical activity may be beyond the reach of many elderly women.

Influence of dietary fat, cholesterol and energy on serum lipids at vigorous physical exercise

Seven healthy male volunteers participated in four different heavy cross-country ski trips in the mountains, 1 year apart, wearing a back-pack weighing 30 kg. Each trip lasted for 8 days covering a total distance of 160 km. Serum triglycerides and lipoprotein cholesterol were measured before and after the trip. The different experiments were carried out with the same participants and under the same conditions, but with a varying diet composition. With the four different diets used, a standard diet (3800 kcal day-1, 26% fat, 260 mg cholesterol day-1), a low-energy diet (2300 kcal day-1, 21% fat, 110 mg cholesterol day-1, a high-fat-high-cholesterol diet (3800 kcal day-1, 52% fat, 480 mg cholesterol day-1) and a high-cholesterol diet (3800 kcal day-1, 29% fat, 410 mg cholesterol day-1), a decrease in very low-density lipoprotein-low-density lipoprotein (VLDL-LDL) fraction by 38%, 50%, 41%, and 54%, respectively, was obtained. No significant increase in high-density lipoprotein (HDL) cholesterol was found in the experiments with the standard diet and the low-energy diet, but in the high-fat-high-cholesterol diet experiment the HDL cholesterol increased by 19% and the ratio HDL cholesterol:total cholesterol from 0.327 to 0.490. With the high-cholesterol diet an increase in HDL cholesterol of about the same extent was obtained. In all experiments the serum triglycerides decreased by more than 30% and no significant difference for the different diets was obtained.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of exercise training on cardiorespiratory function in men and women older than 60 years of age

This study reports the physiologic effects of up to 14 months of aerobic exercise in 101 older (greater than 60 years) men and women. After an extensive baseline physiologic assessment (Time 1), in which aerobic capacity and blood lipids were measured, subjects were randomized to an aerobic exercise condition (cycle ergometry, 3 times per week for 1 hour), nonaerobic yoga (2 times per week for 1 hour), or a waiting list nonexercise control group for 4 months, and then underwent a second (Time 2) assessment. At the completion of the second assessment, all remaining subjects completed 4 months of aerobic exercise and were reevaluated (Time 3). Subjects were given the option of participating in 6 additional months of supervised aerobic exercise, and all available subjects completed a fourth assessment (Time 4) 14 months after their initial baseline evaluation. Results indicated that subjects generally exhibited a 10 to 15% improvement in peak oxygen consumption after 4 months of aerobic exercise training, and a 1 to 6% improvement in aerobic power with additional aerobic exercise training. On the other hand, subjects, especially men, continued to have improvements in submaximal exercise performance (i.e., anaerobic threshold). In addition, aerobic exercise was associated with an improved lipid profile; subjects participating in aerobic exercise for up to 14 months exhibited increased levels of high-density lipoprotein cholesterol. Maintenance of regular aerobic exercise for an extended time interval is associated with greater cardiovascular benefits among older adults than has been reported previously.

Discrepancies between energy intake and expenditure in physically active women

Energy intake and expenditure in women runners and non-runners were assessed by weighed food records, evaluation of minute-by-minute activity diaries, and indirect calorimetry. All participants were adapted to their stated activity levels for at least 6 months and maintained a constant body-weight throughout their participation. Calculated daily energy intake equalled calculated expenditure in non-runners (7300 (SD 1536) v. 7476 (SD 872) kJ/d), but calculated energy expenditure in women running about 54 km/week was found to exceed intake by more than 2700 kJ/d (8259 (SD 1466) v. 10963 (SD 1367), P less than 0.01). The runners showed no evidence of compensating for the increased energy expenditure associated with running by engaging in lower-intensity activities during non-running time. Further, runners did not decrease energy expended at various activities. The findings suggest that women adapted to high levels of activity may possess mechanisms to maintain body-weight without significantly increasing energy intake.

Lipid profile in trained subjects undergoing complete food deprivation combined with prolonged intermittent exercise

Sixteen male subjects [18-21 years, maximal oxygen consumption (VO2max) = 59.2 ml.kg-1.min-1 +/- SEM 5.6] participated in a study to evaluate the effect of prolonged, complete food deprivation combined with physical effort, on plasma lipoprotein concentrations. The subjects were deprived of food for 81 h but were supplied with water: they walked for 10 h a day at 40% of VO2max, covering a total of 105 km. During this period the subjects' average mass decreased significantly (P less than 0.05) reflecting a marked catabolic process. Plasma concentration of low density lipoprotein-cholesterol [( LDL-C]) and triglycerides were significantly lower (P less than 0.05) and total cholesterol, high-density lipoprotein-cholesterol [( HDL-C]), and free fatty acid levels were significantly higher (P less than 0.05) at the end of the experimental period compared to the start. The ratio between plasma [HDL-C] to plasma [LDL-C] increased from 0.51 to 0.89 at the end of the exercise period, reflecting a marked anti-atherogenic effect. All changes were transient and reversible within 12 days of recovery.

Predicting maximal oxygen uptake from treadmill testing in trained and untrained women

This study was conducted to develop an equation to predict maximal oxygen uptake from exercise time during a standardized treadmill test in women aged 29 to 75 years before and after aerobic training. Treadmill tests were administered to 181 women with measurement of maximal oxygen uptake, and an equation predicting maximal oxygen uptake was derived: maximal oxygen uptake (ml.kg-1.min-1) = 10.34 + 1.29 (exercise time), r = 0.88, standard error of the estimate = 2.1, p less than 0.0001. Thirty-three women were retested after 6 and 12 months of aerobic exercise training. Maximal oxygen uptake was predicted from the equation developed and compared with the measured values at 6 and 12 months. The predicted and measured maximal oxygen uptake values after training were not significantly different. These results indicate that it is possible to predict maximal oxygen uptake for clinical purposes with a single equation from exercise time in untrained and trained women across a wide range of ages.

Adolphe Abrahams memorial lecture, 1988. Exercise and lifestyle change

While the evidence for a clustering of health habits is not particularly strong, there are both pedagogic and economic arguments in favour of a multifaceted approach to health education. The present review thus examines the impact of regular physical exercise upon other forms of health behaviour, testing the extent to which an activity programme can be a catalyst of improved lifestyle in both primary and secondary preventive therapy. The conceptual framework of health promotion is examined with particular reference to the models of Skinner, Becker, Fishbein, Triandis and Rokeach. Certain differences are noted between the decision to exercise and the marketing decisions for which Fishbein's model was originally designed. Nevertheless, in its later modifications, it provides a basic framework for understanding how human lifestyle is shaped. Theoretical mechanisms are suggested whereby exercise could influence such behaviours as cigarette smoking, alcohol consumption and drug usage, seat-belt usage, hypertension, body mass, lipid profile, promiscuous sexual behaviour, the carrying of lethal weapons, and acceptance of regular preventive medical examinations. The empirical evidence from both cross-sectional and longitudinal experiments shows a relatively weak association between exercise habits and other desirable forms of health behaviour. Moreover, it is arguable that other forms of health intervention such as smoking withdrawal or dieting might be equally effective as a primary change agent, and much of the observed association between exercise and other health habits could be attributable to a common dependence on demographic and socio-economic factors. On the other hand, the apparent weakness of associations may arise in part from difficulties in measuring both habitual physical activity and other forms of health behaviour, with a resultant attenuation of correlations. Possibly, a stronger association between exercise participation and other favourable health habits would be uncovered if attention were focused upon those forms of endurance exercise currently thought to enhance cardiac health. Given that moderate endurance exercise is also positive and pleasant advice, further examination of the potential of multifaceted but exercise-centered health promotion programmes appears warranted.

Levels of plasma and aortic lipids in young exercised rats with a diminished weight gain

Young exercised rats with a diminished weight gain had a decrease in high density lipoprotein (HDL) cholesterol and phospholipid levels in the plasma and augmented free cholesterol and phosphatide in the aorta. When the weight gain in the trained rats paralleled the gain in non-exercised animals, the values of these lipids were not altered. The levels of aortic free cholesterol in the non-exercised and exercised groups were inversely associated with concentrations of HDL-cholesterol, but were not related to the activities of lecithin cholesterol acyltransferase. In addition, the total cholesterol and phospholipid contents in the aorta negatively correlated with HDL-cholesterol concentrations. We propose that in young exercised rats with a diminished weight gain, the removal of aortic lipids is hampered due to a reduction in HDL-cholesterol.

The acute effect of marathon running on plasma lipoproteins in female subjects

The acute effect of running a 42.2 km marathon race on plasma lipoproteins was investigated in 12 female subjects (aged 21 to 41 years). During the race there was a significant increase (P less than 0.01) in the concentration of total plasma cholesterol. The mean post-race concentration of high density lipoprotein cholesterol (HDL-C) was 64.0 +/- 16.2 (SD) mg 100 ml-1, compared with 52.1 +/- 14.0 mg 100 ml-1 before the race, representing a significant increase (P less than 0.002). There was no significant difference in the concentration of very low density lipoprotein (VLDL) or low density lipoprotein (LDL) before and after the exercise. The mean concentration of the cholesteryl ester moiety of the HDL increased from 43.7 +/- 12.3 to 54.3 +/- 15.7 mg 100 ml-1 (P less than 0.002), while there was no significant changes in the concentration of the unesterified cholesterol, phospholipid, triacylglycerol or protein moieties of the HDL. The relative proportions of apolipoproteins A-I, A-II, C and E remained unchanged during the exercise. The changes in the concentration of each of the lipoprotein fractions observed during the marathon varied considerably between subjects. The individual increases in the concentration of HDL-C ranged from 4.1 to 28.4 mg 100 ml-1, while both increases and decreases in individual concentrations of VLDL and LDL as well as of total plasma cholesterol were observed. These observations suggest that women undergo greater changes in HDL-C concentration that men during acute exercise, while considerable variation between individuals occurs.

Effect of alcohol intake and exercise on plasma high-density lipoprotein cholesterol subfractions and apolipoprotein A-I in women

Abstinence from alcohol consumption for 3 weeks was followed by 3 weeks of wine intake in 18 inactive and 18 physically active premenopausal women (runners). The runners weighed less and had higher plasma high-density lipoprotein (HDL) cholesterol and lower low-density lipoprotein cholesterol levels than the inactive women. There were no differences between groups in plasma total cholesterol, triglyceride and apolipoprotein A-I concentrations. Runners had higher plasma HDL2 cholesterol concentrations than inactive women (34 +/- 17 vs 19 +/- 12 mg/dl), but HDL3 cholesterol concentration did not differ between the groups (41 +/- 10 vs 39 +/- 9 mg/dl). Addition of 35 g/day of ethanol for 3 weeks did not result in a significant change in either group for any of the variables measured. The amount of exercise appears to be a more important determinant of plasma lipoproteins and apolipoprotein A-I than alcohol intake in premenopausal women.

Beta-blockers, diuretics and physical fitness as determinants of serum lipids in myocardial infarction patients

Serum lipid levels were followed in myocardial infarction patients for one year after the infarction and related to their drug use and physical performance. Serum triglyceride concentrations were significantly elevated in patients using diuretics or diuretics and beta-blockers together both 3 and 12 months after the infarction when compared to patients not having drugs. The beta-blockers alone did not change triglycerides. No differences were found in total cholesterol concentration between any of the drug groups. The HDL cholesterol levels were significantly lower in all the drug groups 12 months after the infarction in comparison with the group using no drugs, but 3 months after the infarction these differences were not present. Total work in the exercise stress test correlated negatively with serum triglycerides and total cholesterol and positively with HDL/total cholesterol ratio in the group using no drugs 12 months after the infarction. In beta-blocker users, total work correlated negatively with triglyceride and total cholesterol concentrations. In all drug groups no correlation between total work and HDL/total cholesterol ratio could be found. These data suggest that despite differences in the physical working capacity between the groups, the drugs themselves are major determinants of differences in serum lipids.

HDL-C Concentrations in Weight-Trained, Endurance-Trained, and Sedentary Females

In brief: Serum high-density lipoprotein cholesterol (HDL-C) levels and percent HDL-C were significantly higher in nine female endurance runners than in equal groups of female weight trainers and sedentary female controls. Weight trainers and controls showed no significant differences in HDL-C and percent HDL-C. Subjects who had higher HDL-C levels were more likely to be non-smokers who consumed little alcohol and did not use oral contraceptives. No significant dose-response relationships were found for either runners or weight trainers when daily training duration, weekly training frequency, and weekly mileage were correlated with HDL-C. It was concluded that HDL-C levels in females are associated with specific training methods.

Long-term physical training in female type 1 (insulin-dependent) diabetic patients: absence of significant effect on glycaemic control and lipoprotein levels

No objective evidence has been presented to support the beneficial effect of physical training on glycaemic control in Type 1 (insulin-dependent) diabetic patients trained two to three times a week for several months. In the present study we examined the possibility that a daily exercise programme would be more suitable for improving glycaemic control. Thirteen patients completed a 5-month study; 6 were randomized to exercise training (20 min daily bicycle exercise) and 7 served as non-exercising controls. The training resulted in an 8% increase in maximal oxygen uptake (p less than 0.05). No change in glycaemic control occurred during the study period in either group. In addition, serum lipid and lipoprotein levels were followed. Total cholesterol decreased during the study period irrespective of training. No effect was noted on the levels of LDL, VLDL, HDL and HDL2 cholesterol. A significant training effect was obtained in the HDL3 subfraction (-10%, p less than 0.05). Total triglycerides were unchanged, but a decrease in the level of LDL triglycerides was observed with training (-12%, p less than 0.01). It is concluded that, in female Type 1 diabetic patients, daily physical training for several months does not improve glycaemic control and results only in minor changes in serum lipoprotein profiles.

Alcohol versus exercise for coronary protection

Both alcohol and exercise have been said to protect against coronary heart disease. The epidemiologic data suggest exercise, per se, does, but alcohol, per se, does not protect against coronary heart disease. Recent longitudinal data suggest teetotalers, especially those who have never smoked, have the lowest coronary heart disease mortality of all. Other cross-sectional and longitudinal studies that suggest light drinkers have the lowest coronary heart disease mortality may be biased because: (1) the teetotalers include some ex-drinkers who may have quit drinking because of coronary heart disease; and (2) the light drinkers include some who drink very rarely, and/or drink very small amounts, and/or have a lower risk of coronary heart disease independent of alcohol because they are more health-conscious in general. The metabolic data also suggest exercise, but not alcohol, protects against coronary heart disease. Exercise increases the level of high-density lipoprotein 2, which correlates well with coronary heart disease risk; alcohol in moderation seems to increase the level of high-density lipoprotein 3, which correlates poorly with coronary heart disease risk and may merely reflect hepatic enzyme induction. Exercise and alcohol influence blood pressure, body weight, and glucose tolerance in opposite directions; in each instance, the influence of exercise is beneficial, that of alcohol detrimental, to the prevention of coronary heart disease. There seems to be no reason to use alcohol for coronary protection.

The effects of exercise and weight loss on plasma lipids in young obese men

We studied the independent and combined effects of exercise training and weight loss on blood lipids under fixed diet and exercise conditions. Twenty-one obese sedentary men were randomly allocated to one of four treatment groups: (1) inactive and constant weight (control), (2) exercise training and constant weight, (3) inactive and weight loss, and (4) exercise training and weight loss. There were three study periods: a 3 week baseline period inactive and on an isocaloric diet, a 12 week treatment period, and a 3 week weight stabilization period. Exercise consisted of treadmill walking at an energy cost of 3500 kcal/wk for groups 2 and 4 with replacement caloric intake only in group 2. Group 3 reduced caloric intake by 3500 kcal/wk during the treatment period. Weight loss for groups 3 and 4 were 13.4 pounds and 13.7 pounds, respectively. Maximal oxygen uptake (mL/min) increased 6% in both exercise groups (2 and 4), and percent body fat decreased only in these groups. Regression analysis by group assignment on HDL cholesterol (HDL-C) showed that the inactivity-weight loss modality (group 3) and the exercise-constant weight modality (group 2) each significantly increased HDL-C, with an additive effect of exercise and weight loss (group 4). The rate of HDL-C change differed significantly between groups (P = 0.01). HDL-C increased 0.63, 0.61, and 1.89 mg/dL per 3 weeks or 2%, 2.4%, and 5.5% above baseline levels in groups 2, 3, and 4, respectively, while the control group decreased 0.11 mg/dL. Plasma triglycerides and very low-density lipoprotein (VLDL) cholesterol increased with exercise at constant weight (group 2) and decreased with exercise associated with weight loss (group 4). In conclusion, exercise and weight loss separately and independently increase HDL-C, and their effects are additive.

Elevated high-density lipoprotein cholesterol levels in older endurance athletes

To ascertain whether older (masters) athletes exhibit a more favorable plasma lipoprotein/lipid profile than sedentary men of similar age, 14 endurance-trained masters athletes (mean age 60 +/- 2 years [+/- standard error of the mean]), 12 older, untrained-not lean men (mean age 62 +/- 1 years), 9 older untrained-lean men (mean age 61 +/- 2 years), 15 young endurance-trained athletes (mean age 26 +/- 1 years) and 15 young untrained men (mean age 28 +/- 1 years) were studied. The athletes had higher values for maximal oxygen uptake and lower levels of body fatness compared with the untrained men, regardless of age (p less than 0.05). High-density lipoprotein (HDL) cholesterol was markedly higher in the masters athletes than in the other groups (66 vs 42 to 55 mg/dl, p less than 0.05). The total cholesterol (TC) and low-density lipoprotein cholesterol concentrations of the masters athletes generally were higher than those of the younger groups, similar to those of the older lean men, and lower than those of the older-not lean men (p less than 0.05). The TC/HDL cholesterol ratios were similarly low (2.8 to 3.4) for the athletes and the young untrained men compared with the older untrained men (4.0 to 5.6) (p less than 0.05). Thus, some older endurance athletes exhibit markedly higher HDL cholesterol levels and lower TC/HDL cholesterol ratios compared with their sedentary peers. This favorable plasma lipoprotein profile may indicate a reduced risk of developing coronary artery disease for older men who exercise regularly.

Comparison of dietary and smoking habit changes in physical fitness improvers and nonimprovers

Changes in dietary, smoking, and alcohol intake habits of men who voluntarily increased their physical fitness level (n = 532) were compared with men who did not increase physical fitness (n = 390). These men were middle-aged (average age = 43 years), initially sedentary and free of disease, and had been examined twice at a preventive medicine clinic within a 1- to 6-year period. Subjects were retrospectively assigned to two fitness groups--improvers and nonimprovers--based on changes in treadmill performance between baseline and follow-up examinations. Fifteen lifestyle variables were assessed by questionnaire and evaluated for change. At baseline the two groups were similar in demographic variables and diet, differing significantly only in follow-up interval (P less than 0.001), treadmill time (P less than 0.001), whole milk consumption (P less than 0.003), and smoking (P less than 0.001). At follow-up, positive changes in health habits were seen for both groups. Statistically significant differences in health habit change between the groups were seen only for beef (P less than 0.003) and coffee (P less than 0.003) consumption (consumption of both decreasing in more improvers than nonimprovers). Smokers at baseline were less likely to improve their physical fitness. We concluded that individuals who voluntarily increased their physical fitness level were not more likely to change their dietary and alcohol habits than persons who maintained a more sedentary lifestyle.

Relationship of menopausal status and exercise level to HDL-cholesterol in women

The relationship between exercise habits, menopausal status and HDL cholesterol (HDL-C) was studied in 44 long-distance runners, 47 joggers, and 45 relatively inactive females. In each group, some women were post-menopausal (Post-M) and some pre-menopausal (Pre-M). HDL-C level was higher in runners (77.6 mg/dl) and joggers (70.4 mg/dl) than in the inactive group (62.1 mg/dl), but was not different Pre-M vs Post-M. Total cholesterol (TC) and LDL-C were higher in Post-M than in Pre-M subjects, but did not differ among exercise groups. Body weight and % fat were lower in Pre-M vs Post-M groups and were lower in the runners vs inactive subjects. The HDL-C/TC ratio was higher in the runners vs inactive subjects and there was a significant exercise-menopausal interaction indicating a beneficial exercise effect. Adjustment of lipoprotein values for possible confounding variables did not alter these results. Endurance exercise by Post-M females may help prevent adverse lipid and lipoprotein changes which might predispose them to coronary heart disease.