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

Effects of Different Aerobic Exercises on Blood Lipid Levels in Middle-Aged and Elderly People: A Systematic Review and Bayesian Network Meta-Analysis Based on Randomized Controlled Trials

With increasing age, dyslipidemia becomes a common health problem in the middle-aged and elderly population, posing a significant risk of cardiovascular disease. Aerobic exercise, as a non-pharmacological intervention, is considered to be effective in improving blood lipid levels, but the extent to which different types of aerobic exercise affect blood lipids is not clear. This study aims to investigate the effects of 12 different aerobic exercises on total cholesterol, triglyceride, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol in middle-aged and elderly people aged 45 years and over through systematic review and Bayesian network Meta-analysis of randomized controlled trials. We systematically searched relevant databases and included eligible randomized controlled trials. Bayesian network meta-analysis was used to compare the effects of 12 types of aerobic exercise on lipid levels. A total of 487 randomized controlled trials involving middle-aged and elderly people over 45 years old were included. The results of the network meta-analysis showed that all types of aerobic exercise could reduce blood lipid levels compared with no intervention in middle-aged and elderly people. In terms of total cholesterol, triglyceride, and low-density lipoprotein cholesterol, swimming had the most significant effect. For HDL cholesterol, dance showed a better effect. Studies have shown that swimming and dancing have a positive effect on improving blood lipid levels in middle-aged and elderly people. It is recommended to choose the appropriate type of exercise according to personal preference and physical condition.

Four-Year Increase in Step Cadence Is Associated with Improved Cardiometabolic Health in People with a History of Prediabetes

PURPOSE

To investigate associations between 4-yr change in step cadence and markers of cardiometabolic health in people with a history of prediabetes and to explore whether these associations are modified by demographic factors.

METHODS

In this prospective cohort study, adults, with a history of prediabetes, were assessed for markers of cardiometabolic health (body mass index, waist circumference, high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol [LDL-C], triglycerides, and glycated hemoglobin A1c [HbA1c]), and free-living stepping activity (activPAL3™) at baseline, 1 yr, and 4 yr. Brisk steps per day were defined as the number of steps accumulated at ≥100 steps per minute and slow steps per day as those accumulated at <100 steps per minute; the mean peak stepping cadence during the most active 10 minutes of the day was also derived. Generalized estimating equations examined associations between 4-yr change in step cadence and change in cardiometabolic risk factors, with interactions by sex and ethnicity.

RESULTS

Seven hundred ninety-four participants were included (age, 59.8 ± 8.9 yr; 48.7% women; 27.1% ethnic minority; total steps per day, 8445 ± 3364; brisk steps per day, 4794 ± 2865; peak 10-min step cadence, 128 ± 10 steps per minute). Beneficial associations were observed between change in brisk steps per day and change in body mass index, waist circumference, HDL-C, and HbA1c. Similar associations were found between peak 10-min step cadence and HDL-C and waist circumference. Interactions by ethnicity revealed change in brisk steps per day and change in peak 10-min step cadence had a stronger association with HbA1c in White Europeans, whereas associations between change in 10-min peak step cadence with measures of adiposity were stronger in South Asians.

CONCLUSIONS

Change in the number of daily steps accumulated at a brisk pace was associated with beneficial change in adiposity, HDL-C, and HbA1c; however, potential benefits may be dependent on ethnicity for outcomes related to HbA1c and adiposity.

Walking for hypertension

BACKGROUND

Increased physical activity has been recommended as an important lifestyle modification for the prevention and control of hypertension. Walking is a low-cost form of physical activity and one which most people can do. Studies testing the effect of walking on blood pressure have revealed inconsistent findings.

OBJECTIVES

To determine the effect of walking as a physical activity intervention on blood pressure and heart rate.

SEARCH METHODS

We searched the following databases up to March 2020: the Cochrane Hypertension Specialised Register, CENTRAL (2020, Issue 2), Ovid MEDLINE, Ovid Embase, CINAHL, PsycINFO, SPORTDiscus, PEDro, the WHO International Clinical Trials Registry Platform, and ClinicalTrials.gov. We also searched the following Chinese databases up to May 2020: Index to Taiwan Periodical Literature System; National Digital Library of Theses and Dissertation in Taiwan; China National Knowledge Infrastructure (CNKI) Journals, Theses & Dissertations; and Wanfang Medical Online. We contacted authors of relevant papers regarding further published and unpublished work. The searches had no language restrictions.

SELECTION CRITERIA

Randomised controlled trials of participants, aged 16 years and over, which evaluated the effects of a walking intervention compared to non-intervention control on blood pressure and heart rate were included.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Where data were not available in the published reports, we contacted authors. Pooled results for blood pressure and heart rate were presented as mean differences (MDs) between groups with 95% confidence intervals (CIs). We undertook subgroup analyses for age and sex. We undertook sensitivity analyses to assess the effect of sample size on our findings.

MAIN RESULTS

A total of 73 trials met our inclusion criteria. These 73 trials included 5763 participants and were undertaken in 22 countries. Participants were aged from 16 to 84 years and there were approximately 1.5 times as many females as males. The characteristics of walking interventions in the included studies were as follows: the majority of walking interventions was at home/community (n = 50) but supervised (n = 36 out of 47 reported the information of supervision); the average intervention length was 15 weeks, average walking time per week was 153 minutes and the majority of walking intensity was moderate. Many studies were at risk of selection bias and performance bias. Primary outcome We found moderate-certainty evidence suggesting that walking reduces systolic blood pressure (SBP) (MD -4.11 mmHg, 95% CI -5.22 to -3.01; 73 studies, n = 5060). We found moderate-certainty evidence suggesting that walking reduces SBP in participants aged 40 years and under (MD -4.41 mmHg, 95% CI -6.17 to -2.65; 14 studies, n = 491), and low-certainty evidence that walking reduces SBP in participants aged 41 to 60 years (MD -3.79 mmHg, 95% CI -5.64 to -1.94, P < 0.001; 35 studies, n = 1959), and those aged 60 years of over (MD -4.30 mmHg, 95% CI -6.17 to -2.44, 24 studies, n = 2610). We also found low certainty-evidence suggesting that walking reduces SBP in both females (MD -5.65 mmHg, 95% CI -7.89 to -3.41; 22 studies, n = 1149) and males (MD -4.64 mmHg, 95% CI -8.69 to -0.59; 6 studies, n = 203). Secondary outcomes We found low-certainty evidence suggesting that walking reduces diastolic blood pressure (DBP) (MD -1.79 mmHg, 95% CI -2.51 to -1.07; 69 studies, n = 4711) and heart rate (MD -2.76 beats per minute (bpm), 95% CI -4.57 to -0.95; 26 studies, n = 1747). We found moderate-certainty evidence suggesting that walking reduces DBP for participants aged 40 years and under (MD -3.01 mmHg, 95% CI -4.44 to -1.58; 14 studies, n = 491) and low-certainty evidence suggesting that walking reduces DBP for participants aged 41 to 60 years (MD -1.74 mmHg, 95% CI -2.95 to -0.52; 32 studies, n = 1730) and those aged 60 years and over (MD -1.33 mmHg, 95% CI -2.40 to -0.26; 23 studies, n = 2490). We found moderate-certainty evidence that suggests walking reduces DBP for males (MD -2.54 mmHg, 95% CI -4.84 to -0.24; 6 studies, n = 203) and low-certainty evidence that walking reduces DBP for females (MD -2.69 mmHg, 95% CI -4.16 to -1.23; 20 studies, n = 1000). Only 21 included studies reported adverse events. Of these 21 studies, 16 reported no adverse events, the remaining five studies reported eight adverse events, with knee injury being reported five times.

AUTHORS' CONCLUSIONS

Moderate-certainty evidence suggests that walking probably reduces SBP. Moderate- or low-certainty evidence suggests that walking may reduce SBP for all ages and both sexes. Low-certainty evidence suggests that walking may reduce DBP and heart rate. Moderate- and low-certainty evidence suggests walking may reduce DBP and heart rate for all ages and both sexes.

Exercise and Hyperlipidemia

Hyperlipidemia is one of the common pathological conditions of human, which occurs due to lipid metabolism disorder in the human body, resulting in serum lipid concentration beyond normal levels. Due to heredity, diet, nutrition, medicine, and other factors, the incidence of hyperlipidemia has been significantly enhanced and has become one of the most common pathological condition of the human. By introducing the background and pathogenesis of hyperlipidemia and the positive effects of exercise on a variety of related diseases, this chapter discusses the relationship between exercise and serum lipid concentration and the effects of different types of exercise on hyperlipidemia.

Heart rate recovery as a sensitive indicator of physical activity changes in perimenopausal and postmenopausal women

Heart rate recovery (HRR), which is defined as the rate of heart rate decline after cessation of exercise, is an important indicator of exercise tolerance. The aim of this study was to investigate the effect of a 4-month moderate reduction in physical activity on pre-exercise and exercise heart rate (HR) as well as HRR after exercise cessation in perimenopausal and postmenopausal women. 10 physically active females, 62.5±3.0 years old, participated in this study. They performed an 8-min constant power output (~50W) cycling exercise at an intensity corresponding to about 65% of maximal heart rate. Heart rate was measured continuously starting from 1 minute before exercise, during the exercise test and 3 min after exercise cessation. Furthermore, before and after exercise, blood pressure (BP) and tympanic temperature (Tt) were measured. The exercise test was performed twice, before and after a 4-month reduction in physical activity. 4 months of the slight reduction in physical activity (by ~16%) did not cause any changes in pre-exercise and exercise HR, however, significantly higher HR during the 1st min after exercise (p=0.03), as well slower HRR (p=0.03), were reported. No effects of the reduction in physical activity were observed in resting and post-exercise BP and Tt. Even a slight reduction in physical activity is accompanied by a lower rate of HRR , which indicates a decrease in exercise tolerance. These results indicate that HRR is a sensitive indicator of physical capacity also in peri- and postmenopausal women, since the changes in HRR in response to physical activity level occur earlier than changes in pre-exercise and exercise heart rate. heart rate, heart rate recovery, physical activity in the elderly

Seasonal variation in sports participation

This study explores indicators describing socio-demographics, sports participation characteristics and motives which are associated with variation in sports participation across seasons. Data were drawn from the German Socio-Economic Panel which contains detailed information on the sports behaviour of adults in Germany. Overall, two different measures of seasonal variation are developed and used as dependent variables in our regression models. The first variable measures the coefficient of (seasonal) variation in sport-related energy expenditure per week. The second variable measures whether activity drops below the threshold as defined by the World Health Organization (WHO). Results suggest that the organisational setting, the intensity and number of sports practised, and the motive for participation are strongly correlated with the variation measures used. For example, both, participation in a sports club and a commercial facility, are associated with reduced seasonal variation and a significantly higher probability of participating at a volume above the WHO threshold across all seasons. These findings give some impetus for policymaking and the planning of sports programmes as well as future research directions.

Physical activity level and risk of death: the severance cohort study

Background

Physical activity decreases deaths from cardiovascular disease and other causes; however, it is unclear whether physical activity is associated with cancer incidence and death in Asian populations.

Methods

Data from 59 636 Koreans aged 30 to 93 years were collected using a questionnaire and medical examination at the Severance Hospital Health Promotion Center between 1994 and 2004. Study participants were followed for a mean duration of 10.3 years.

Results

In the exercising group, the multivariate Cox proportional hazards model showed a lower risk of cancer death (hazard ratio [HR] = 0.72, 95% CI = 0.62–0.85) in men but not in women. Those who exercised, as compared with those who did not, had lower risks of all-cause death (men: HR = 0.68, 95% CI = 0.60–0.76; women: HR = 0.65, 95% CI = 0.53–0.79) and noncancer death (men: 0.63, 0.53–0.75; women: 0.52, 0.39–0.69). Physical activity was inversely associated with risk of noncancer death among men and women.

Conclusions

Physical activity was associated with lower risks of cancer death and noncancer death.

Does dog-ownership influence seasonal patterns of neighbourhood-based walking among adults? A longitudinal study

BACKGROUND

In general dog-owners are more physically active than non-owners, however; it is not known whether dog-ownership can influence seasonal fluctuations in physical activity. This study examines whether dog-ownership influences summer and winter patterns of neighbourhood-based walking among adults living in Calgary, Canada.

METHODS

A cohort of adults, randomly sampled from the Calgary metropolitan area, completed postal surveys in winter and summer 2008. Both winter and summer versions of the survey included questions on dog-ownership, walking for recreation, and walking for transportation in residential neighbourhoods. Participation in neighbourhood-based walking was compared, among dog-owners and non-owners, and in summer and winter, using general linear modeling. Stability of participation in neighbourhood-based walking across summer and winter among dog-owners and non-owners was also assessed, using logistic regression.

RESULTS

A total of 428 participants participated in the study, of whom 115 indicated owning dogs at the time of both surveys. Dog-owners reported more walking for recreation in their neighbourhoods than did non-owners, both in summer and in winter. Dog-owners were also more likely than non-owners to report participation in walking for recreation in their neighbourhoods, in summer as well as in winter. Dog-owners and non-owners did not differ in the amount of walking that they reported for transportation, either in summer or in winter.

CONCLUSIONS

By acting as cues for physical activity, dogs may help their owners remain active across seasons. Policies and programs related to dog-ownership and dog-walking, such as dog-supportive housing and dog-supportive parks, may assist in enhancing population health by promoting physical activity.

A comparison of the effects of swimming and walking on body weight, fat distribution, lipids, glucose, and insulin in older women--the Sedentary Women Exercise Adherence Trial 2

All types of aerobic exercise are assumed to affect cardiovascular risk similarly. There are few studies of swimming, but complex responses to water-based exercise suggest its potential for differential effects. The aim of the study was to compare the effects of swimming and walking on fitness, body weight, lipids, glucose, and insulin in older women. Sedentary women aged 50 to 70 years (N = 116), randomly assigned to swimming or walking plus usual care or a behavioral intervention, completed 3 sessions per week of moderate-intensity exercise, supervised for 6 months then unsupervised for 6 months. After 6 months, 1.6-km walk time decreased in walkers and swimmers, with greater improvement in walkers (1.0 vs 0.6 minute, P = .001). In swimmers, but not walkers, distance swum in 12 minutes increased (78.1 vs -2.2 m, P = .021). Waist and hip circumferences (80.8 vs 83.1 cm and 101.8 vs 102.4 cm; P = .023 and P = .042, respectively) and insulin area under the curve (oral glucose tolerance test) (5128 vs 5623 μU/[L 120 min], P < .05) were lower with swimming. Lipids did not differ between groups. At 12 months, fitness was maintained. Relative to walking, swimming reduced body weight by (1.1 kg, P = .039) and resulted in lower total and low-density lipoprotein cholesterol (0.3 and 0.2 mmol/L; P = .040 and P = .049, respectively). The magnitude of the difference in the reduction of insulin area under the curve between swimming and walking was greater at 12 months; however, the significance was attenuated (4677 vs 5240 μU/[L 120 min], P = .052). Compared with walking, swimming improved body weight, body fat distribution, and insulin in the short term and, in the longer term, body weight and lipid measures. These findings suggest that the type of exercise can influence health benefits.

Objective and subjective assessments of normal walking pace, in comparison with that recommended for moderate intensity physical activity

Despite its common application and widely reported health benefits, walking, in relation to pace and intensity, is under-researched. Few studies have addressed whether people normally walk at a pace that meets the public health recommendations for moderate intensity physical activity (1.34-1.79 ms-1) and there is no known research on individuals' perceptions of factors which influence walking pace. This study aimed to objectively assess if participants were reaching the pace required for moderate intensity physical activity during normal walking. This was examined via a Global Positioning System (GPS) over a 1 km outdoor walk and a timed 150 m trial. In both tests participants (n=10, 3 men, 7 women, mean age 54±8 y) were instructed to walk at their normal pace. Through short interviews, the study also investigated the factors that participants' thought influenced their pace. All participants successfully walked at a pace considered as moderate intensity (≥1.34 ms-1). Height was significantly correlated with normal walking pace. The interviews provided an in depth insight into factors that affect walking pace; ground surface and footwear were mentioned frequently and the influence of the weather provided conflicting views, prompting a need for further research in the area. The GPS device showed enormous potential as a human locomotion measurement tool, enabling participants to walk unobstructed and unobserved in an outdoor setting, making the results relevant to real life situations.

Randomised controlled trial of home-based walking programmes at and below current recommended levels of exercise in sedentary adults

OBJECTIVES

To determine, using unsupervised walking programmes, the effects of exercise at a level lower than currently recommended to improve cardiovascular risk factors and functional capacity.

DESIGN

12 week randomised controlled trial.

SETTING

Northern Ireland Civil Service; home-based walking.

PARTICIPANTS

106 healthy, sedentary 40 to 61 year old adults of both sexes.

INTERVENTIONS

Participants were randomly allocated to a walking programme (30 minutes brisk walking three days a week (n = 44) or five days a week (n = 42)) or a control group (n = 20). Participants could choose to walk in bouts of at least 10 minutes. They used pedometers to record numbers of steps taken. Intention to treat analysis of changes within groups was done using paired t tests; extent of change (baseline to 12 week measurements) was compared between groups using analysis of variance and Gabriel's post hoc test.

MAIN OUTCOME MEASURES

Blood pressure, serum lipids, body mass index, waist:hip ratio, and functional capacity (using a 10 m shuttle walk test).

MAIN RESULTS

89% (93/106) completed the study. Systolic blood pressure and waist and hip circumferences fell significantly both in the three day group (5 mm Hg, 2.6 cm, and 2.4 cm, respectively) and in the five day group (6 mm Hg, 2.5 cm, and 2.2 cm) (p<0.05). Functional capacity increased in both groups (15%; 11%). Diastolic blood pressure fell in the five day group (3.4 mm Hg, p<0.05). No changes occurred in the control group.

CONCLUSIONS

This study provides evidence of benefit from exercising at a level below that currently recommended in healthy sedentary adults. Further studies are needed of potential longer term health benefits for a wider community from low levels of exercise.

Inactivity, exercise training and detraining, and plasma lipoproteins. STRRIDE: a randomized, controlled study of exercise intensity and amount

Exercise has beneficial effects on lipoproteins. Little is known about how long the effects persist with detraining or whether the duration of benefit is effected by training intensity or amount. Sedentary, overweight subjects ( n = 240) were randomized to 6-mo control or one of three exercise groups: 1) high-amount/vigorous-intensity exercise; 2) low-amount/vigorous-intensity exercise; or 3) low-amount/moderate-intensity exercise. Training consisted of a gradual increase in amount of exercise followed by 6 mo of exercise at the prescribed level. Exercise included treadmill, elliptical trainer, and stationary bicycle. The number of minutes necessary to expend the prescribed kilocalories per week (14 kcal·kg body wt−1·wk−1for both low-amount groups; 23 kcal·kg body wt−1·wk−1for high-amount group) was calculated for each subject. Average adherence was 83–92% for the three groups; minutes per week were 207, 125, and 203 and sessions per week were 3.6, 2.9, and 3.5 for high-amount/vigorous-intensity, low-amount/vigorous intensity, and low-amount/moderate-intensity groups, respectively. Plasma was obtained at baseline, 24 h, 5 days, and 15 days after exercise cessation. Continued inactivity resulted in significant increases in low-density lipoprotein (LDL) particle number, small dense LDL, and LDL-cholesterol. A modest amount of exercise training prevented this deterioration. Moderate-intensity but not vigorous-intensity exercise resulted in a sustained reduction in very-low-density lipoprotein (VLDL)-triglycerides over 15 days of detraining ( P < 0.05). The high-amount group had significant improvements in high-density lipoprotein (HDL)-cholesterol, HDL particle size, and large HDL levels that were sustained for 15 days after exercise stopped. In conclusion, physical inactivity has profound negative effects on lipoprotein metabolism. Modest exercise prevented this. Moderate-intensity but not vigorous-intensity exercise resulted in sustained VLDL-triglyceride lowering. Thirty minutes per day of vigorous exercise, like jogging, has sustained beneficial effects on HDL metabolism.

Effects of 6 months of walking training on lower limb muscle and tendon in elderly

The purpose of this study was to investigate the effects of 6 months of walking training on muscle strength, muscle thickness and tendon stiffness on various parts of the lower limbs in the elderly. Subjects were assigned to training (n=35) and control (n=10) groups. Maximal isometric torque (MVC) and muscle thickness for knee extensors (KE), knee flexors (KF), dorsi flexors (DF) and plantar flexors (PF) were measured. Tendon stiffness for KE and PF was measured using ultrasonography while subjects performed isometric contraction. No significant changes occurred in any measured variables in the control group. In the training group, muscle thickness increased significantly for KF and DF, but not for PF. For KE, significant increases of muscle thickness at the proximal and medial sides were observed, although mean relative increase of the eight measured sites for KE was not significant. MVC increased significantly for KF, DF, and PF, but not for KE. In addition, tendon stiffness for KE and PF did not change after training. These results indicated that walking training brought about increments of muscle thickness and strength in most of the lower limbs in the elderly, but it did not result in any changes in tendon stiffness.

The effect of walking on fitness, fatness and resting blood pressure: a meta-analysis of randomised, controlled trials

OBJECTIVE

The purpose of this review was to perform a meta-analysis on walking intervention studies in order to quantify the magnitude and direction of walking-induced changes that may alter selected cardiovascular risk factors.

METHOD

Twenty-four randomised controlled trials of walking were assessed for quality on a three-point scale. Data from these studies were pooled and treatment effects (TEs) were calculated for six traditional cardiovascular risk variables: body weight, body mass index (BMI), percentage body fat, aerobic fitness (V(O(2) )max in ml kg(-1) min(-1)) and resting systolic and diastolic blood pressure. Weighted TEs were analysed using a random effects model with weights obtained using the inverse of the individual TE variances. Random effects models were used to investigate the influence of both study quality and exercise volume (<150 vs. > or =150 min week(-1)).

RESULTS

Random effects modelling showed that walking interventions increased V(O(2) )max and decreased body weight, BMI, percent body fat and resting diastolic blood pressure in previously sedentary adults (p<0.05 for all).

CONCLUSION

The results of this study provide evidence that healthy but sedentary individuals who take up a programme of regular brisk walking improves several known risk factors for cardiovascular disease.

Evaluating a community-based walking intervention for hypertensive older people in Taiwan: a randomized controlled trial

OBJECTIVE

To study the effect of a community-based walking intervention on blood pressure among older people.

METHOD

The study design was a randomized controlled trial conducted in a rural area of Taiwan between October 2002 and June 2003. A total of 202 participants aged 60 years and over with mild to moderate hypertension was recruited. Participants randomized to the intervention group (n=102) received a six-month community-based walking intervention based on self-efficacy theory. A public health nurse provided both face-to-face and telephone support designed to assist participants to increase their walking. Control group participants (n=100) received usual primary health care. Primary outcome was change in systolic blood pressure and secondary outcomes were exercise self-efficacy, self-reported walking and diastolic blood pressure.

RESULTS

At six-month follow-up the mean change in systolic blood pressure was a decrease of 15.4 mmHg and 8.4 mmHg in the intervention and control group, respectively. The difference in mean change between the two groups was -7.0 mmHg (95% CI, -11.5 to -2.5 mmHg, p=0.002). Improvement in exercise self-efficacy scores was greater among intervention group participants (mean difference 1.23, 95% CI, 0.5 to 2.0, p=0.001). Intervention group participants were more likely to report walking more (p<0.0005) but no differences were observed in diastolic blood pressure (p=0.19).

CONCLUSIONS

Among hypertensive older people, a six-month community-based walking intervention was effective in increasing their exercise self-efficacy and reducing systolic blood pressure.

Efficacy of a pedometer-based physical activity program on parameters of diabetes control in type 2 diabetes mellitus

The aim of the study was to determine whether a recommendation to walk 10000 steps per day would result in significant improvements in glycemic control, insulin sensitivity, and cardiovascular risk in patients with type 2 diabetes mellitus. The study was a 6-week randomized controlled trial that included 30 patients with type 2 diabetes mellitus. After 10 days of baseline activity, patients were randomized into 2 groups: control and active. The control group (n = 15) was instructed to continue with their baseline activity for 6 weeks. The active group (n = 15) was instructed to walk at least 10000 steps per day 5 or more days per week, for 6 weeks. Data relevant to glycemic control and other parameters of health were collected at study weeks 0 and 6. There were no differences in the baseline activity between groups (P = .36). Subjects in the active group significantly increased physical activity by 69% during the intervention phase of the study (P = .002), whereas there was no change in the physical activity of the control group (P > .05). High-density lipoprotein cholesterol and resting energy expenditure significantly increased in the active group (P < .05). Finally, plasminogen activator inhibitor 1 (PAI-1) activity was reduced by exercise relative to the control group (P = .03). There were no differences in any other study parameters during the 6-week study. In conclusion, short-term intervention with a pedometer increased physical activity and positively affected plasminogen activator inhibitor 1 activity in previously inactive patients with type 2 diabetes mellitus. The use of a pedometer may prove to be an effective tool for promoting healthy lifestyle changes that include daily physical activity and self-monitoring of therapeutic goals.

The Effectiveness of Walking in Preventing Cardiovascular Disease in Women: A Review of the Current Literature

This paper summarizes research examining the effects of walking on the prevention of cardiovascular disease (CVD) and treatment of CVD risk factors in women. Epidemiological evidence indicates that walking reduces a woman's risk for developing CVD. Walking may lower CVD risk by having beneficial effects on risk factors associated with CVD development. Obesity, dyslipidemia, hypertension, and diabetes can all be positively affected by increased physical activity or, more specifically, increased daily walking in women. With a large number of people living a sedentary lifestyle, it is important to focus on the effects of physical activity options that are both physiologically beneficial and personally appealing and available to the majority of individuals. With studies showing positive results using pedometer- monitored walking to decrease CVD risk, accumulated daily walking as opposed to structured walking activity should also be considered as a viable option in women.

Different forms of physical activity and cardiovascular risk factors among 24???64-year-old men and women in Finland

BACKGROUND

There is convincing evidence that regular physical activity reduces risk factors for cardiovascular diseases (CVD) among men. However, only a few studies have been conducted among women. Most previous studies have focused on the effects of leisure-time physical activity on cardiovascular risk factors, without considering the impact of occupational or commuting physical activity.

DESIGN

Four independent cross-sectional surveys were carried out at 5-year intervals within the framework of the FINMONICA studies in 1982, 1987, 1992 and 1997.

METHODS

An independent random sample was drawn from the national population register for each survey. The samples were stratified by sex and 10-year age categories according to the WHO MONICA protocol. The survey consisted of a self-administered questionnaire.

RESULTS

Not only leisure-time physical activity, but also commuting activity was directly associated with high-density lipoprotein (HDL)-cholesterol and was inversely related to body mass index (BMI) and waist circumference among both men and women. High occupational physical activity was related to high HDL-cholesterol levels and high total serum cholesterol levels in both sexes and to lower BMI, waist circumference and diastolic blood pressure (DBP) in men. High leisure-time physical activity was associated with reduced DBP among both men and women, whereas high occupational physical activity was related to lower DBP only among men.

CONCLUSION

Not only leisure-time physical activity but also commuting activity is associated with reduced levels of some cardiovascular risk factors. All forms of physical activity should be promoted to reduce CVD in the population.

Brisk walking, fitness, and cardiovascular risk: a randomized controlled trial in primary care

STUDY OBJECTIVE

To examine the effects of 30 min of self-paced, non-supervised, brisk walking, 5 days per week on the health and fitness of people aged 50-65 years.

DESIGN

Randomized controlled trial. Members of the intervention group (n = 21) were directed to walk briskly for 30 min, 5 days per week, for 12 weeks. Individuals were given the choice to complete the 30 min of walking in one session or in shorter bouts of no less than 10 min. They were asked to record in a diary the time spent walking and the number of steps taken during a single walk using a pedometer. Participants in the control group (n = 10) were asked to maintain their habitual lifestyle and not change their activity or dietary habits. Measurements of body mass index (BMI), waist/hip ratio (WHR), blood pressure, functional capacity, total cholesterol, triglyceride, and lipoprotein subfractions were taken before and after the program. Changes in 10-year risk estimate for coronary heart disease and stroke were calculated using Framingham risk equations.

SETTING

Three urban general practices patients: 31 healthy, sedentary 50- to 65-year-old participants recruited following contact by their general practitioner.

MAIN RESULTS

The mean time spent walking by the intervention group was 27.72 (+/-9.79) min/day: their adherence to the protocol was 90.3%. Significant decreases in systolic and diastolic blood pressure, reduction in stroke risk, and increased functional capacity were found within the walking group between baseline and 12-week measurements. No changes were found in these parameters within the control group. Significant reductions in 10-year risk of CHD were observed in both groups. No significant changes were found in lipid levels or anthropometric measurements in either group.

CONCLUSIONS

The study provides evidence for the benefit to fitness and cardiovascular risk of the "30-min brisk walking, 5 days a week" message to people aged 50-65 years who participated in an unsupervised home-based walking program. Further study to overcome the problem of poor recruitment and determine the minimum effective dose of exercise to improve cardiovascular risk prediction scores is required.

Greater beneficial effects of visceral fat reduction compared with subcutaneous fat reduction on parameters of the metabolic syndrome: a study of weight reduction programmes in subjects with visceral and subcutaneous obesity

AIMS

To evaluate the effect of weight reduction on parameters of the metabolic syndrome in obese patients according to their pattern of abdominal fat distribution.

METHODS

A longitudinal intervention study, consisting of a 12-week weight reduction programme, including lifestyle modification and adjuvant appetite suppressant, in 38 subjects with visceral obesity and 47 subjects with subcutaneous obesity. Visceral, subcutaneous and total adipose tissue areas were determined by CT scan at the level of L4-L5. Parameters for components of the metabolic syndrome were measured before and after weight reduction.

RESULTS

Reductions in body weight, BMI and subcutaneous adipose tissue area were greater in the subcutaneous than in the visceral obesity group. In contrast, changes in fasting plasma glucose, insulin, and HOMA score were higher in the visceral than in the subcutaneous obesity group. Changes in visceral adipose tissue area were significantly related to changes in fasting plasma glucose, triglycerides and HOMA score.

CONCLUSIONS

Visceral fat reduction induced greater beneficial effects on parameters of the metabolic syndrome than subcutaneous fat reduction. Evaluation of changes in abdominal fat distribution is necessary when obese subjects enter a weight reduction programme.

Physical activity in relation to cardiovascular disease and total mortality among men with type 2 diabetes

BACKGROUND

The present study was conducted to examine the relationship of physical activity with risk of cardiovascular disease (CVD) and mortality among men with type 2 diabetes. CVD risk and mortality are increased in type 2 diabetes. Few epidemiological studies have investigated the effect of physical activity on these outcomes among type 2 diabetics.

METHODS AND RESULTS

Of the 3058 men who reported a diagnosis of diabetes at age 30 years or older in the Health Professionals' Follow-up Study (HPFS), we excluded 255 who reported a physical impairment. In the remaining 2803 men, physical activity was assessed every 2 years; 266 new cases of CVD and 355 deaths of all causes were identified during 14 years of follow-up. Relative risks of CVD and death were estimated from Cox proportional hazards analysis with adjustment for potential confounders. The multivariate relative risks of CVD incidence corresponding to quintiles of total physical activity were 1.0, 0.87, 0.64, 0.72, and 0.67 (Ptrend=0.07). The corresponding multivariate relative risks for total mortality were 1.0, 0.80, 0.57, 0.58, and 0.58 (Ptrend=0.005). Walking was associated with reduced risk of total mortality. Relative risks across quintiles of walking were 1.0, 0.97, 0.87, 0.97, and 0.57 (Ptrend=0.002). Walking pace was inversely associated with CVD, fatal CVD, and total mortality independently of walking hours.

CONCLUSIONS

Physical activity was associated with reduced risk of CVD, cardiovascular death, and total mortality in men with type 2 diabetes. Walking and walking pace were associated with reduced total mortality.

Speed and exercise intensity of recreational walkers

BACKGROUND

Brisk walking has been identified as an activity suited to meet American College of Sport Medicine/Centers for Disease Control and Prevention recommendations for moderate intensity exercise (55-69% HR(max), 40-59% VO(2)R). However, little is known about whether recreational walkers self-select a pace which elicits this intensity and how they interpret the term "brisk walking."

METHODS

The walking speed of 82 adults was covertly observed in a public park. Fifty-nine of these participants demonstrated their interpretation of "brisk walking" and the speed was noted. Eleven of these subjects subsequently walked on a treadmill at their observed and "brisk walk" speeds. Heart rate (HR), respiratory gases, and ratings of perceived exertion (RPE) were measured.

RESULTS

Mean observed and "brisk" walking speeds were 1.56 +/- 0.17 m. s(-1) and 1.79 +/- 0.19 m x s(-1) respectively (P < or = 0.001). Mean exercise intensities during the treadmill test (n = 11) were 59.0 +/- 13.4% VO(2max) and 67.3 +/- 11.6% HR(max) for the observed speed (1.60 + 0.24 m x s(-1)). The brisk speed (1.86 +/- 0.12 m x s(-1)) equated to 68.6 +/- 14.9% VO(2max) and 78.5 +/- 15.5% HR(max).

CONCLUSION

The speed and intensity selected by this group of walkers meets current recommendations for moderate intensity exercise. Instructing individuals to "walk briskly" prompts more vigorous activity.

Effects of long-term moderate exercise and increase in number of daily steps on serum lipids in women: randomised controlled trial [ISRCTN21921919]

BACKGROUND: This study was designed to evaluate the effects of a 24-month period of moderate exercise on serum lipids in menopausal women. METHODS: The subjects (40--60 y) were randomly divided into an exercise group (n = 14) and a control group (n = 13). The women in the exercise group were asked to participate in a 90-minute physical education class once a week and to record their daily steps as measured by a pedometer for 24 months. RESULTS: Mean of daily steps was significantly higher in the exercise group from about 6,800 to over 8,500 steps (P < 0.01). In the control group, the number of daily steps ranged from 5,700 to 6,800 steps throughout the follow-up period. A significant interaction between the exercise group and the control group in the changes og total cholesterol (TC), high-density lipoprotein cholesterol (HDLC) and TC : HDLC ratio could be observed (P < 0.05). By multiple regression analysis, the number of daily steps was related to HDLC and TC : HDLC levels after 24 months, and the changes in TC and HDLC concentrations. CONCLUSIONS: These results suggest that daily exercise as well as increasing the number of daily steps can improve the profile of serum lipids.

Long-term effects of exercise on blood pressure and lipids in healthy women aged 40-65 years: The Sedentary Women Exercise Adherence Trial (SWEAT)

OBJECTIVES

To evaluate the long-term effects of regular moderate or vigorous intensity exercise on blood pressure and blood lipids in previously sedentary older women.

DESIGN

Subjects were randomly assigned to either a supervised centre-based (CB) or a minimally supervised home-based (HB) exercise program, initially for 6 months. Within each program, subjects were further randomized to exercise either at moderate (40-55% heart rate reserve, HRres) or vigorous intensity (65-80% HRres). After 6 months, all groups continued a HB moderate or vigorous exercise program for another 12 months.

METHODS

Healthy, sedentary women (aged 40-65 years) (n = 126) were recruited from the community. Subjects exercised three times per week for 30 min. They were evaluated at baseline, 6, 12 and 18 months.

RESULTS

There was a significant fall of 2.81 mmHg in systolic blood pressure (P = 0.049) and 2.70 mmHg in diastolic blood pressure (P = 0.004) after correction for age and baseline values with moderate exercise, but not with vigorous-intensity exercise. When this analysis was repeated with the change in body mass included, the results were unchanged. After correction for potential confounding factors, there was a significant fall in total cholesterol and low density lipoprotein cholesterol with vigorous but not moderate exercise at 6 months (P < 0.05) but not at 18 months.

CONCLUSIONS

In this largely normotensive population of older women, a moderate, but not vigorous exercise program, achieved sustained falls in resting systolic and diastolic blood pressure over 18 months. The study demonstrates that, in older women, moderate intensity exercise is well accepted, sustainable long-term and has the health benefit of reduced blood pressure.

Cardiorespiratory and metabolic characteristics of detraining in humans

Detraining can be defined as the partial or complete loss of training-induced adaptations, in response to an insufficient training stimulus. Detraining is characterized, among other changes, by marked alterations in the cardiorespiratory system and the metabolic patterns during exercise. In highly trained athletes, insufficient training induces a rapid decline in VO2max, but it remains above control values. Exercise heart rate increases insufficiently to counterbalance the decreased stroke volume resulting from a rapid blood volume loss, and maximal cardiac output is thus reduced. Cardiac dimensions are also reduced, as well as ventilatory efficiency. Consequently, endurance performance is also markedly impaired. These changes are more moderate in recently trained subjects in the short-term, but recently acquired VO2max gains are completely lost after training stoppage periods longer than 4 wk. From a metabolic viewpoint, even short-term inactivity implies an increased reliance on carbohydrate metabolism during exercise, as shown by a higher exercise respiratory exchange ratio. This may result from a reduced insulin sensitivity and GLUT-4 transporter protein content, coupled with a lowered muscle lipoprotein lipase activity. These metabolic changes may take place within 10 d of training cessation. Resting muscle glycogen concentration returns to baseline within a few weeks without training, and trained athletes' lactate threshold is also lowered, but still remains above untrained values.

Detraining: loss of training-induced physiological and performance adaptations. Part II: Long term insufficient training stimulus

This part II discusses detraining following an insufficient training stimulus period longer than 4 weeks, as well as several strategies that may be useful to avoid its negative impact. The maximal oxygen uptake (VO2max) of athletes declines markedly but remains above control values during long term detraining, whereas recently acquired VO2max gains are completely lost. This is partly due to reduced blood volume, cardiac dimensions and ventilatory efficiency, resulting in lower stroke volume and cardiac output, despite increased heart rates. Endurance performance is accordingly impaired. Resting muscle glycogen levels return to baseline, carbohydrate utilisation increases and the lactate threshold is lowered, although it remains above untrained values in the highly trained. At the muscle level, capillarisation, arterial-venous oxygen difference and oxidative enzyme activities decline in athletes and are completely reversed in recently trained individuals, contributing significantly to the long term loss in VO2max. Oxidative fibre proportion is decreased in endurance athletes, whereas it increases in strength athletes, whose fibre areas are significantly reduced. Force production declines slowly, and usually remains above control values for very long periods. All these negative effects can be avoided or limited by reduced training strategies, as long as training intensity is maintained and frequency reduced only moderately. On the other hand, training volume can be markedly reduced. Cross-training may also be effective in maintaining training-induced adaptations. Athletes should use similar-mode exercise, but moderately trained individuals could also benefit from dissimilar-mode cross-training. Finally, the existence of a cross-transfer effect between ipsilateral and contralateral limbs should be considered in order to limit detraining during periods of unilateral immobilisation.

The effect of aerobic exercise training on the lipid-lipoprotein profile of children and adolescents

Longitudinal paediatric population studies have provided evidence that the risk factor theory may be extended to children and adolescents. These studies could assist in identifying individuals at increased coronary risk. Numerous studies have focused on the effects of regular exercise on the paediatric lipoprotein profile, a recognised primary risk factor, with equivocal results. Cross-sectional comparisons of dichotomised groups provide the strongest evidence of an exercise effect. 'Trained' or 'active' children and adolescents demonstrate 'favourable' levels of high density lipoprotein-cholesterol (HDL-C), triacylglycerol, total cholesterol (TC)/HDL-C and low density lipoprotein-cholesterol (LDL-C)/HDL-C, whilst TC is generally unaffected. The evidence regarding LDL-C in these studies is equivocal. A possible self-selection bias means that a cause-effect relationship between exercise and the lipoprotein profile cannot be readily established from this design. Correlational studies are difficult to interpret because of differences in participant characteristics, methods employed to assess peak oxygen uptake and habitual physical activity (HPA), and the statistical techniques used to analyse multivariate data. Directly measured cardiorespiratory fitness does not appear to be related to lipoprotein profiles in the children and adolescents studied to date, although there are data to the contrary. The relationship with HPA is more difficult to decipher. The evidence suggests that a 'favourable' lipoprotein profile may be related to higher levels of HPA, although differences in assessment methods preclude a definitive answer. While few prospective studies exist, the majority of these longitudinal investigations suggest that imposed regular exercise has little, if any, influence on the lipoprotein levels of children and adolescents. However, most prospective studies have several serious methodological design weaknesses, including low sample size, inadequate exercise training volume and a lack of control individuals. Recent studies have suggested that increases in HDL-C and reductions in LDL-C may be possible with regular exercise. The identification of a dose-response relationship between exercise training and the lipoprotein profile during the paediatric years remains elusive.

Effects of low-intensity aerobic training on the high-density lipoprotein cholesterol concentration in healthy elderly subjects

The concentration of high-density lipoprotein cholesterol (HDL-C) is inversely correlated with the risk of coronary heart disease. The effects of low-intensity aerobic training on serum HDL-C and other lipoprotein concentrations were examined in healthy elderly subjects. The subjects were randomly assigned to two groups matched for sex, age, height, and weight. The training group (n = 20, 10 men and 10 women aged 67 +/- 4 years) participated in a supervised physical exercise regimen using a bicycle ergometer at an intensity of 50% estimated maximal oxygen consumption (VO2max) for 60 minutes two to four times per week for 5 months. In contrast, the control group (n = 20, 10 men and 10 women aged 68 +/- 4 years) did not perform any particular physical training. The training protocol resulted in significant increases in the VO2max (P < .05), HDL-C, HDL2-C, and HDL2-C/HDL3-C ratio (P < .01). The change in HDL2-C (r = .57, P < .01) and HDL2-C/HDL3-C (r = .63, P < .01) was positively associated with an increase in the total exercise duration per week. In addition, the total weekly exercise duration also showed a significant positive relationship with HDL-C (r = .75, P < .01), HDL2-C (r = .81, P < .01), and HDL2-C/HDL3-C (r = .71, P < .01) after the training period. The changes in body weight and the VO2max were not significantly correlated with any lipid parameters. Low-intensity aerobic training may improve the profile of HDL-C and its subfractions in healthy elderly subjects. Also, the total exercise duration may be an important factor for improving HDL-C and HDL2-C in elderly subjects.

The effect of two different 18-week walking programmes on aerobic fitness, selected blood lipids and factor XIIa

Forty-nine previously sedentary or low active individuals aged 40-71 years were allocated to three groups. The long walking group participated in an 18-week walking programme which consisted of walks lasting 20-40 min; the repetitive short walking group completed walks of between 10 and 15 min, up to three times a day, with no less than 120 min between each walk; and the control group maintained their low level of activity. Both walking programmes began at a prescribed 60 min x week(-1), which increased steadily up to 200 min x week(-1) by week 12. During the study, the long walking group walked for an estimated 2514 min (139 min x week(-1)), expending an estimated 67.5 MJ (3.72 MJ x week(-1)) at an estimated 73% of their age-predicted maximum heart rate and 68% of their estimated VO2max. The repetitive short walking group walked for an estimated 2476 min (135 min x week(-1)), expending an estimated 58.5 MJ (3.17 MJ x week(-1)) at an estimated 71% of their age-predicted maximum heart rate and 65% of their estimated VO2max. The results showed a statistically significant reduction in heart rate during a standardized step test (pre- vs post-intervention) in both walking groups, indicating an improvement in aerobic fitness, although the control group showed a higher average heart rate during the post-intervention test, indicating reduced fitness. When compared with the male subjects pre-intervention, the females possessed more favourable levels of high-density lipoprotein (HDL) cholesterol (P< 0.001), apolipoprotein (apo) AI (P < 0.001) and ratios of total cholesterol:HDL cholesterol (P< 0.02) and low-density lipoprotein (LDL) cholesterol: HDL cholesterol (P< 0.02). Compared with the controls post-intervention, the walking groups showed no statistically significant changes in total cholesterol, LDL cholesterol, HDL cholesterol, apo AI, apo AII, apo B, or the ratios of total cholesterol: HDL cholesterol, LDL cholesterol: HDL cholesterol, apo AI: apo B or apo AI: apo AII (P > 0.05). Relative to the walking groups, factor XIIa increased in the control group (P < 0.05). We conclude that, although both walking programmes appeared to improve aerobic fitness, there was no evidence of improvements in the blood lipids or associated apolipoproteins of the walking groups. Further analysis indicated that this apparent lack of change may have been related to the subjects' relatively good pre-intervention blood lipid profiles, which restricted the potential for change. The implications of the observed changes in the coagulation/fibrinolytic factors remain unclear.

Training effects of short and long bouts of brisk walking in sedentary women

This study compared the effects of short and long bouts of brisk walking in sedentary women. Forty seven women aged 44.4 +/- 6.2 yr (mean +/- SD) were randomly assigned to either three 10-min walks per day (short bouts), one 30-min walk per day (long bouts) or no training (control). Brisk walking was done on 5 d x wk(-1), at 70 to 80% of maximal heart rate, typically at speeds between 1.6 and 1.8 m x s(-1) (3.5 and 4.0 mph), for 10 wk. Subjects agreed not to make changes to their diet. Twelve short-bout walkers, 12 long-bout walkers, and 10 controls completed the study. Relative to controls, VO2max (short-bout, +2.3 +/- 0.1 mL x kg(-1) x min(-1); long-bout, +2.4 +/- 0.1 mL x kg(-1) x min(-1); controls, -0.5 +/- 0.1 mL x kg(-1) x min[-1]) and the VO2 at a blood lactate concentration of 2 mmol x L(-1) increased in walkers (both P < 0.05), with no difference in response between walking groups. Neither heart rate during standard, submaximal exercise nor resting systolic blood pressure changed in a different way in walkers and controls. The sum of four skinfold thicknesses decreased in both walking groups (P < 0.05) but body mass (short-bout, -1.7 +/- 1.7 kg; long-bout, -0.9 +/- 2.0 kg; controls, +0.6 +/- 0.7 kg) and waist circumference decreased significantly only in short-bout walkers. Changes in anthropometric variables did not differ between short- and long-bout walkers. Thus short bouts of brisk walking resulted in similar improvements in fitness and were at least as effective in decreasing body fatness as long bouts of the same total duration.

Body fat distribution predicts cardiac risk factors in older female coronary patients

BACKGROUND

After myocardial infarction, women have higher rates of recurrent coronary events than men. This is caused, at least in part, by a higher prevalence of obesity-related coronary risk factors such as hyperlipidemia, hypertension, sedentary lifestyle, insulin resistance, and diabetes. We studied the relationship between measures of body fat distribution, body composition, aerobic fitness, and dietary intake and several coronary risk factors including lipids, glucose, and insulin levels.

METHODS

The study population included 20 women > 60 years of age with recently diagnosed coronary heart disease and a comparison group of 50 healthy women with low-risk coronary risk profiles. Dependent variables included lipid subfractions (fasting, triglycerides, high-density lipoprotein [HDL] cholesterol, and low-density lipoprotein [LDL] cholesterol), glucose levels, and serum insulin levels.

RESULTS

Waist-to-hip ratio (WHR) was the best predictor of serum triglyceride levels (r = .65, P = .002), HDL cholesterol level (r = .46, P = .05), and fasting serum insulin levels (r = .76, P < .001) whereas peak oxygen consumption (Peak VO2) was the best predictor of LDL cholesterol (r = .73, P < .001). In a combined population of the 20 coronary patients and 50 healthy age-matched controls, WHR remained the best predictor of serum triglyceride levels (r = .57, P < .001) and insulin levels (r = .63, P < .001) and Peak V02 was the best predictor of HDL (r = .40, P < .001) and LDL cholesterol (r = .57, P = .004).

CONCLUSIONS

Body fat distribution and peak aerobic fitness, both modifiable factors, are significant predictors of risk factors for second coronary events in older female coronary patients.

Effects of an 18 week walking programme on cardiac function in previously sedentary or relatively inactive adults

OBJECTIVE

To investigate the effects of an 18 week walking programme upon cardiac function.

METHODS

29 sedentary or relatively inactive but otherwise healthy subjects (15 walkers and 14 controls, aged 40-68 years) completed the study. The walkers completed a progressive 18 week walking programme which required an estimated average energy expenditure of 900 kcal week-1 for the total duration of the study and 1161 kcal week-1 during the final six weeks. Walking was carried out at an intensity of 67.8 (SD 4.99)% of maximum oxygen consumption and 73.8(6.99%) of maximum heart rate. Before and after the intervention all subjects underwent an M mode echocardiogram, graded treadmill walking test, and step test for the assessment of aerobic fitness.

RESULTS

After 18 weeks the results of the control group showed no change in any of the variables measured while the walkers showed a statistically significant increase in the velocity of relaxation of the longitudinal myocardial fibres of the left ventricle and a decrease in heart rate measured during the step tests, indicating an improvement in aerobic capacity.

CONCLUSIONS

Walking promotes improvements in cardiovascular fitness. Moderate forms of exercise may improve cardiac function.

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.