Abstract: Background Increased physical activity is related to reduced risk of cardiovascular disease, possibly because it leads to improvement in the lipoprotein profile. However, the amount of exercise training required for optimal benefit is unknown. In a prospective, randomized study, we investigated the effects of the amount and intensity of exercise on lipoproteins. Methods A total of 111 sedentary, overweight men and women with mild-to-moderate dyslipidemia were randomly assigned to participate for six months in a control group or for approximately eight months in one of three exercise groups: high-amount–high-intensity exercise, the caloric equivalent of jogging 20 mi (32.0 km) per week at 65 to 80 percent of peak oxygen consumption; low-amount–high-intensity exercise, the equivalent of jogging 12 mi (19.2 km) per week at 65 to 80 percent of peak oxygen consumption; or low-amount–moderate-intensity exercise, the equivalent of walking 12 mi per week at 40 to 55 percent of peak oxygen consumption. Subjects we...

Abstract: Background The role of walking, as compared with vigorous exercise, in the prevention of cardiovascular disease remains controversial. Data for women who are members of minority racial or ethnic groups are particularly sparse. Methods We prospectively examined the total physical-activity score, walking, vigorous exercise, and hours spent sitting as predictors of the incidence of coronary events and total cardiovascular events among 73,743 postmenopausal women 50 to 79 years of age in the Women's Health Initiative Observational Study. At base line, participants were free of diagnosed cardiovascular disease and cancer, and all participants completed detailed questionnaires about physical activity. We documented 345 newly diagnosed cases of coronary heart disease and 1551 total cardiovascular events. Results An increasing physical-activity score had a strong, graded, inverse association with the risk of both coronary events and total cardiovascular events. There were similar findings among white women and bl...

Abstract: The effect of physical exercise on mental function has been widely studied from the beginning of the 20th century. However, the contradictory findings of experimental research have led authors to identify several methodological factors to control in such studies including: (i) the nature of the psychological task; and (ii) the intensity and duration of physical exercise. The purpose of this article is to provide information, from the perspective of performance optimisation, on the main effects of physical task characteristics on cognitive performance. Within this framework, some consistent results have been observed during the last decade. Recent studies, using mainly complex decisional tasks, have provided the research community with clear support for an improvement of cognitive performance during exercise. Diverse contributing factors have been suggested to enhance cognitive efficacy. First, an increase in arousal level related to physical exertion has been hypothesised. Improvement in decisional performance has been observed immediately after the adrenaline threshold during incremental exercise. Such positive effects could be enhanced by nutritional factors, such as carbohydrate or fluid ingestion, but did not seem to be influenced by the level of fitness. Second, the mediating role of resource allocation has been suggested to explain improvement in cognitive performance during exercise. This effect highlights the importance of motivational factors in such tasks. Finally, when the cognitive performance was performed during exercise, consistent results have indicated that the dual task effect was strongly related to energetic constraints of the task. The greater the energy demand, the more attention is used to control movements.

Abstract: OBJECTIVES: Although deficits in skeletal muscle strength, gait, balance, and oxygen uptake are potentially reversible causes of frailty, the efficacy of exercise in reversing frailty in community-dwelling older adults has not been proven. The aim of this study was to determine the effects of intensive exercise training (ET) on measures of physical frailty in older community-dwelling men and women. DESIGN: Randomized controlled trial. SETTING: Medical school research center. PARTICIPANTS: One hundred fifteen sedentary men and women (mean age ± standard deviation = 83 ± 4) with mild to moderate physical frailty, as defined by two of the following three criteria: Modified Physical Performance Test (modified PPT) score between 18 and 32, peak oxygen uptake (.VO2 peak) between 10 and 18 mL/kg/min, and self-report of difficulty or assistance with one basic activity of daily living (ADL), or two instrumental ADLs. INTERVENTION: Participants were randomly assigned to a control group that performed a 9-month low-intensity home exercise program (control) or an exercise-training program (ET). The control intervention primarily consisted of flexibility exercises. ET began with 3 months of flexibility, light-resistance, and balance training. During the next 3 months, resistance training was added, and, during the next 3 months, endurance training was added. MEASUREMENTS: Modified PPT score, .VO2 peak, performance of ADLs as measured by the Older Americans Resources and Services instrument, and the Functional Status Questionnaire (FSQ). RESULTS: ET resulted in significantly greater improvements than home exercise in three of the four primary outcome measures. Adjusted 95% confidence bounds on the magnitude of improvement in the ET group compared with the control group were 1.0 to 5.2 points for the modified PPT score, 0.9 to 3.6 mL/kg/min for .VO2 peak, and 1.6 to 4.9 points for the FSQ score. CONCLUSIONS: Our results show that intensive ET can improve measures of physical function and preclinical disability in older adults who have impairments in physical performance and oxygen uptake and are not taking hormone replacement therapy better than a low-intensity home exercise program.

Abstract: Background: Physical activity has been associated with a reduced risk of coronary heart disease, but the mechanism underlying this association is unclear. Because coronary heart disease is increasingly seen as an inflammatory process, it might be reasonable to hypothesize that physical activity reduces risk of coronary heart disease by reducing or preventing inflammation. Methods: The study examined the relationship between physical activity and elevated inflammation as indicated by a high C-reactive protein level, white blood cell count, or fibrinogen level. Study subjects were 3638 apparently healthy US men and women 40 years and older who participated in the Third National Health and Nutrition Examination Survey. Results: More frequent physical activity was independently associated with a lower odds of having an elevated C-reactive protein level. Compared with those engaging in physical activity 0 to 3 times per month, the odds of having an elevated C-reactive protein level was reduced among those engaging in physical activity 4 to 21 times per month (odds ratio, 0.77; 95% confidence interval, 0.58-1.02) and 22 or more times per month (odds ratio, 0.63; 95% confidence interval, 0.43-0.93) (P for trend, .02). Similar associations were seen for white blood cell count and fibrinogen levels. Conclusions: More frequent physical activity is independently associated with a lower odds of having elevated inflammation levels among apparently healthy US adults 40 years and older, independent of several confounding factors. The results suggest that the association between physical activity and reduced coronary heart disease risk may be mediated by anti-inflammatory effects of regular physical activity. Arch Intern Med. 2002;162:1286-1292

Abstract: Insulin resistance of skeletal muscle glucose transport is a key defect in the development of impaired glucose tolerance and Type 2 diabetes. It is well established that both an acute bout of exerc...

Abstract: Multiple sclerosis (MS) patients of an inpatient rehabilitation program have been randomly assigned to an exercise training (MS-ET) or nontraining group (MS-NI). Before and after 4 weeks of aerobic exercise training, a graded maximal exercise test with measurement of gas exchange and a lung function test was administered to all 26 patients fulfilling the inclusion criteria. Activity level, fatigue and health perception were measured by means of questionnaires. Twenty-six healthy persons served as control group and were matched in respect of age, gender and activity level. Training intervention consisted of 5x30 min sessions per week of bicycle exercise with individualised intensity. Compared with baseline, the MS training group demonstrated a significant rightward placement of the aerobic threshold (AT) (VO2+13%; work rate [WR])+11%), an improvement of health perception (vitality+46%; social interaction+36%), an increase of activity level (+17%) and a tendency to less fatigue. No changes were observed for the MS-NI group and the control groups. Maximal aerobic capacity and lung function were not changed by either training or nontraining in all four groups. Overall compliance to the training program was quite low (65%), whereas incidence of symptom exacerbation by physical activity has been lower than expected (6%).

Abstract: The ankle brachial index is more closely associated with leg function in persons with peripheral arterial disease than is intermittent claudication or other leg symptoms. These data support the use...

Abstract: This article critically reviews the evidence that exercise is effective in treating depression in adults. Depression is recognised as a mood state, clinical syndrome and psychiatric condition, and traditional methods for assessing depression (e.g. standard interviews, questionnaires) are described. In order to place exercise therapy into context, more established methods for treating clinical depression are discussed. Observational (e.g. cross-sectional and correlational) and interventional studies of exercise are reviewed in healthy adults, those with comorbid medical conditions, and patients with major depression. Potential mechanisms by which exercise may reduce depression are described, and directions for future research in the area are suggested. The available evidence provides considerable support for the value of exercise in reducing depressive symptoms in both healthy and clinical populations. However, many studies have significant methodological limitations. Thus, more data from carefully conducted clinical trials are needed before exercise can be recommended as an alternative to more traditional, empirically validated pharmacological and behavioural therapies.

Abstract: The purpose of this meta-analysis is to review studies investigating the efficacy of inspiratory muscle training (IMT) in chronic obstructive pulmonary disease (COPD) patients and to find out whether patient characteristics influence the efficacy of IMT. A systematic literature search was performed using the Medline and Embase databases. On the basis of a methodological framework, a critical review was performed and summary effect-sizes were calculated by applying fixed and random effects models. Both IMT alone and IMT as adjunct to general exercise reconditioning significantly increased inspiratory muscle strength and endurance. A significant effect was found for dyspnoea at rest and during exercise. Improved functional exercise capacity tended to be an additional effect of IMT alone and as an adjunct to general exercise reconditioning, but this trend did not reach statistical significance. No significant correlations were found for training effects with patient characteristics. However, subgroup analysis in IMT plus exercise training revealed that patients with inspiratory muscle weakness improved significantly more compared to patients without inspiratory muscle weakness. From this review it is concluded that inspiratory muscle training is an important addition to a pulmonary rehabilitation programme directed at chronic obstructive pulmonary disease patients with inspiratory muscle weakness. The effect on exercise performance is still to be determined.

Abstract: Objective To determine the effects of stretching before and after exercising on muscle soreness after exercise, risk of injury, and athletic performance.

Abstract: The effects of resistance exercise combined with vascular occlusion on muscle function were investigated in highly trained athletes. Elite rugby players (n = 17) took part in an 8 week study of exercise training of the knee extensor muscles, in which low-intensity [about 50% of one repetition maximum] exercise combined with an occlusion pressure of about 200 mmHg (LIO, n = 6), low-intensity exercise without the occlusion (LI, n = 6), and no exercise training (untrained control, n = 5) were included. The exercise in the LI group was of the same intensity and amount as in the LIO group. The LIO group showed a significantly larger increase in isokinetic knee extension torque than that in the other two groups (P < 0.05) at all the velocities studied. On the other hand, no significant difference was seen between LI and the control group. In the LIO group, the cross-sectional area of knee extensors increased significantly (P < 0.01), suggesting that the increase in knee extension strength was mainly caused by muscle hypertrophy. The dynamic endurance of knee extensors estimated from the decreases in mechanical work production and peak force after 50 repeated concentric contractions was also improved after LIO, whereas no significant change was observed in the LI and control groups. The results indicated that low-intensity resistance exercise causes, in almost fully trained athletes, increases in muscle size, strength and endurance, when combined with vascular occlusion.

Abstract: In intense exercise (>80% VO(2max)), unlike at lesser intensities, glucose is the exclusive muscle fuel. It must be mobilized from muscle and liver glycogen in both the fed and fasted states. Therefore, regulation of glucose production (GP) and glucose utilization (GU) have to be different from exercise at <60% VO(2max), in which it is established that the portal glucagon-to-insulin ratio causes the less than or equal to twofold increase in GP. GU is subject to complex regulation by insulin, plasma glucose, alternate substrates, other humoral factors, and muscle factors. At lower intensities, plasma glucose is constant during postabsorptive exercise and declines during postprandial exercise (and often in persons with diabetes). During such exercise, insulin secretion is inhibited by beta-cell alpha-adrenergic receptor activation. In contrast, in intense exercise, GP rises seven- to eightfold and GU rises three- to fourfold; therefore, glycemia increases and plasma insulin decreases minimally, if at all. Indeed, even an increase in insulin during alpha-blockade or during a pancreatic clamp does not prevent this response, nor does pre-exercise hyperinsulinemia due to a prior meal or glucose infusion. At exhaustion, GU initially decreases more than GP, which leads to greater hyperglycemia, requiring a substantial rise in insulin for 40--60 min to restore pre-exercise levels. Absence of this response in type 1 diabetes leads to sustained hyperglycemia, and mimicking it by intravenous infusion restores the normal response. Compelling evidence supports the conclusion that the marked catecholamine responses to intense exercise are responsible for both the GP increment (that occurs even during glucose infusion and postprandially) and the restrained increase of GU. These responses are normal in persons with type 1 diabetes, who often report exercise-induced hyperglycemia, and in whom the clinical challenge is to reproduce the recovery period hyperinsulinemia. Intense exercise in type 2 diabetes requires additional study.

Abstract: Background Depression is common in later life. Aims To determine whether exercise is effective as an adjunct to antidepressant therapy in reducing depressive symptoms in older people. Method Patients were randomised to attend either exercise classes or health education talks for 10 weeks. Assessments were made ‘blind’ at baseline, and at 10 and 34 weeks. The primary outcome was seen with the 17-item Hamilton Rating Scale for Depression (HRSD). Secondary outcomes were seen with the Geriatric Depression Scale, Clinical Global Impression and Patient Global Impression. Results At 10 weeks a significantly higher proportion of the exercise group (55% v. 33%) experienced a greater than 30% decline in depression according to HRSD (OR=2.51, P =0.05, 95% CI 1.00-6.38). Conclusions Because exercise was associated with a modest improvement in depressive symptoms at 10 weeks, older people with poorly responsive depressive disorder should be encouraged to attend group exercise activities.

Abstract: The purpose of this study was to compare the magnitude and mechanisms of ankle dorsiflexor muscle fatigue in 20 young (33 ± 6 yr, mean ± SD) and 21 older (75 ± 6 yr) healthy men and women of similar physical activity status. Noninvasive measures of central and peripheral (neuromuscular junction, sarcolemma) muscle activation, muscle contractile function, and intramuscular energy metabolism were made before, during, and after incremental isometric exercise. Older subjects fatigued less than young (P < 0.01); there was no effect of gender on fatigue (P = 0.24). For all subjects combined, fatigue was modestly related to preexercise strength (r = 0.49,P < 0.01). Neither central (central activation ratio) nor peripheral (compound muscle action potential) activation played a significant role in fatigue in any group. During exercise, intracellular concentrations of Pi and H2PO 4 − increased more and pH fell more in young compared with older subjects (P < 0.01) and in men compared with women (P < 0.01). These var...

Abstract: OBJECTIVE Overweight and obesity are common clinical problems encountered in the treatment of bipolar disorder. We therefore assessed the prevalence and clinical correlates of overweight, obesity, and extreme obesity in 644 bipolar patients. METHOD 644 outpatients with DSM-IV bipolar disorder in the Stanley Foundation Bipolar Treatment Outcomes Network were evaluated with structured diagnostic interviews and clinician- and self-administered questionnaires to determine bipolar disorder diagnoses, demographic and historical illness characteristics, comorbid Axis I diagnoses, medical histories, health habits, and body mass indices (BMMs). RESULTS Fifty-eight percent of the patients with bipolar disorder were overweight, 21% were obese, and 5% were extremely obese. American patients had significantly higher mean (p < .0001) BMIs and significantly higher rates of obesity (p < .001) and extreme obesity (p < .001) than European patients. Significant associations (p < or = .001) were found between overweight, obesity. and extreme obesity and gender, age, income level, comorbid binge-eating disorder, hypertension, arthritis, diabetes mellitus, exercise habits, and coffee consumption. Current BMI and weight were each correlated with the number of weight gain-associated psychotropics to which patients had been exposed. Multinomial logistic regression (adjusted for site and eating disorder diagnosis and corrected for multiple comparisons) showed that (1) overweight was significantly associated with male gender and hypertension (p < .001), (2) obesity was significantly associated with hypertension (p < .001), and (3) extreme obesity was significantly associated with hypertension and arthritis (p < .001). CONCLUSION Overweight, obesity, and extreme obesity were common in this group of bipolar patients, although it was unclear that their prevalence rates were truly elevated, because overweight and obesity are increasingly common public health problems among the general population. Correlates of overweight and obesity in bipolar disorder include patient and treatment variables such as gender, geographical location, comorbid binge-eating disorder, age, income level, degree of exposure to weight gain-associated psychotropics, medical disorders associated with obesity, and health habits.

Abstract: BURNHAM, T. R., and A. WILCOX. Effects of exercise on physiological and psychological variables in cancer survivors. Med. Sci. Sports Exerc., Vol. 34, No. 12, pp. 1863–1867, 2002.PurposeThe primary purpose of this study was to examine the effect of aerobic exercise on physiological and psych

Abstract: Study design A randomized controlled trial with a 6-month follow-up period was conducted. Objective To compare lumbar extension exercise and whole-body vibration exercise for chronic lower back pain. Summary of background data Chronic lower back pain involves muscular as well as connective and neural systems. Different types of physiotherapy are applied for its treatment. Industrial vibration is regarded as a risk factor. Recently, vibration exercise has been developed as a new type of physiotherapy. It is thought to activate muscles via reflexes. Methods In this study, 60 patients with chronic lower back pain devoid of "specific" spine diseases, who had a mean age of 51.7 years and a pain history of 13.1 years, practiced either isodynamic lumbar extension or vibration exercise for 3 months. Outcome measures were lumbar extension torque, pain sensation (visual analog scale), and pain-related disability (pain disability index). Results A significant and comparable reduction in pain sensation and pain-related disability was observed in both groups. Lumbar extension torque increased significantly in the vibration exercise group (30.1 Nm/kg), but significantly more in the lumbar extension group (+59.2 Nm/kg; SEM 10.2; P 0.2). Conclusions The current data indicate that poor lumbar muscle force probably is not the exclusive cause of chronic lower back pain. Different types of exercise therapy tend to yield comparable results. Interestingly, well-controlled vibration may be the cure rather than the cause of lower back pain.

Abstract: Objectives. High exercise intensity may be associated with reduced adherence to exercise programmes, possibly because it is perceived as aversive. However, several authors have suggested that an intensity as high as 60% or 70% of maximal aerobic capacity (VO2max) is necessary for exercise to elicit positive affective changes. To elucidate this discrepancy, the affective responses to increasing levels of exercise intensity were examined. Design. In total, 30 volunteers rated their affect every minute as they ran on a treadmill while the speed and grade were progressively increased. Method. The methodology was unique in three respects: (1) affect was assessed in terms of the dimensions of the circumplex model instead of distinct affective states, (2) affect was assessed repeatedly before, during, and after exercise, not only before and after, and (3) exercise intensity was standardized across participants in terms of metabolically comparable phases (beginning, ventilatory threshold, VO2max) instead of percentages of maximal capacity. Results. Pre-to-post-exercise comparisons indicated affective beneets in the form of increased energetic arousal and decreased tense arousal. During exercise, however, affective valence deteriorated beyond the ventilatory threshold and until VO2max, a trend that reversed itself instantaneously during cool-down. Conclusions. Exercise intensity that requires a transition to anaerobic metabolism can have a transient but substantial negative impact on affect and this may, in turn, reduce adherence to exercise programmes.

Abstract: VINCENT, K. R., and R. W. BRAITH. Resistance exercise and bone turnover in elderly men and women. Med. Sci. Sports Exerc., Vol. 34, No. 1, 2002, pp. 17–23.PurposeThis investigation examined the effect of 6 months of high- or low-intensity resistance exercise (REX) on bone mineral density (BMD) and b

Abstract: Pain sensitivity has been found to be altered following exercise. A number of investigators have found diminished sensitivity to pain (hypoalgesia) during and following exercise. However, currently it is unknown whether there is a specific intensity of exercise that is required to produce this hypoalgesia response. Aerobic exercise, such as cycling and running, have been studied most often, and a number of different exercise protocols have been used in this research including: (i) increasing exercise intensity by progressively increasing the workloads; (ii) prescribing a particular exercise intensity based on a percentage of maximum; and (iii) having participants self-select the exercise intensity. Results indicate that hypoalgesia occurred consistently following high-intensity exercise. In the studies in which exercise intensity was increased by increasing workloads, hypoalgesia was found most consistently with a workload of 200 W and above. Hypoalgesia was also found following exercise prescribed at a percentage of maximal oxygen uptake (e.g. 60 to 75%). Results are less consistent for studies that prescribed exercise based on percentage of heart rate maximum, as well as for studies that let participants self-select the exercise intensity. However, there has not been a systematic manipulation of exercise intensity in most of the studies conducted in this area. In addition, the interaction between exercise intensity and exercise duration, more than likely influences whether hypoalgesia occurs following exercise. There is a need for research to be conducted in which both intensity and duration of exercise are manipulated in a systematic manner to determine the 'optimal dose' of exercise that is required to produce hypoalgesia. In addition, there is a need for more research with other modes of exercise (e.g. resistance exercise, isometric exercise) to determine the optimal dose of exercise required to produce hypoalgesia.

Abstract: Aerobic exercise training improves endothelial vasomotor function in the coronary circulation of patients with coronary artery disease (CAD), an effect that has been attributed to local repetitive increases in shear stress on the endothelium. To study the effects of exercise on endothelial function in the peripheral circulation, we used vascular ultrasound to examine flow-mediated dilation and nitroglycerin-mediated dilation in the brachial and posterior tibial arteries of 58 subjects with CAD. Studies were performed at baseline and after 10 weeks in 40 subjects (aged 59 ± 10 years) who participated in a supervised cardiac rehabilitation program that predominantly involved moderate intensity leg exercise (three 30-minute sessions/week), and 18 matched patients who did not exercise and maintained a sedentary lifestyle. Exercise was associated with a 29% increase in functional capacity (7.3 ± 2.2 vs 9.4 ± 2.7 METs, p <0.001), and significant improvement in endothelium-dependent, flow-mediated dilation in a conduit artery of the leg, but not the arm. Nitroglycerin-mediated dilation in the upper arm and lower extremity was unaffected. These findings suggest that exercise improves endothelial function in peripheral conduit arteries of patients with CAD and that the beneficial effect may be more marked in the vascular beds of the exercised limbs.

Abstract: To examine the plasma interleukin (IL)-6 response in elderly (E) and young (Y) humans, 10 E and 10 Y subjects completed 60 min of eccentric lower limb exercise at the same relative oxygen uptake. Plasma IL-6 was measured before, immediately after, and 5 days into recovery from exercise, as were the biochemical markers of muscle damage, creatine kinase (CK), and myoglobin. In both groups, IL-6 increased (P < 0.05) immediately after exercise and peaked 4 h after exercise at 4.35 +/- 1.7 vs. 5.05 +/- 3.17 pg/ml for E and Y subjects, respectively. However, the increase in IL-6 in both groups was modest relative to the increases in CK peaking at 539 +/- 413 vs. 10,301 +/- 5,863 U/l for E and Y subjects, respectively. In addition, the increase in IL-6 was less pronounced (P < 0.05) in E subjects compared with Y subjects. These results suggest that IL-6 increases progressively after eccentric exercise, suggesting that this increase is related to muscle damage. However, the modest increase in IL-6, despite large increases in CK, suggests that the IL-6 response to muscle damage does not make an important contribution to the large increase in IL-6 observed during concentric exercise of long duration. Our data also suggest that aging may be associated with impaired repair mechanisms for exercise-induced muscle damage.

Abstract: LAGALLY, K. M., R. J. ROBERTSON, K. I. GALLAGHER, F. L. GOSS, J. M. JAKICIC, S. LEPHART, and B. GOODPASTER. Perceived exertion, electromyography, and blood lactate during acute bouts of resistance exercise. Med. Sci. Sports Exerc., Vol. 34, No. 3, pp. 552–559, 2002.PurposeThis study examined ratings