Health locus of control of joggers and nonexercisers

To gain a better understanding of why some people engage in regular leisure-time physical exercise while others remain sedentary, the Multidimensional Health Locus of Control scale was distributed to 123 younger joggers and 93 nonexercisers. Analysis of the responses indicated that the joggers scored significantly higher on the internal subscale than did the nonexercisers. No significant differences were found on the Chance and Powerful Others subscales. The disparity of these results from those of other studies of the relationship between locus of control and exercise suggest that an exercise specific locus of control scale needs to be developed. The confound of age with exercise and locus of control requires clarification.

Jogging causes acute changes in the knee joint: an MR study in normal volunteers

As MR imaging allows evaluation of soft-tissue structures not previously possible with imaging techniques, we undertook a preliminary study to evaluate the effects of a popular form of exercise (jogging) on the knee. The specific question prompting our investigation was, does repetitive impulse loading produced by jogging cause acute structural changes within the knee that are visible by MR imaging? The knees of 10 healthy subjects were examined on a 1.5-T MR system before and immediately after 30 min of continuous jogging. The same extremity was examined each time, and the imaging sequences and photographic technique (meniscal windows) were identical for both examinations. Effusions developed in five of 10 subjects after exercise. In addition, five of 10 subjects had subtle increased signal intensity within their menisci. These results suggest that jogging frequently leads to acute changes in the knee that are visible on MR imaging. The significance of these changes is unknown.

Characteristics of urban sidewalks/streets and objectively measured physical activity

Several studies have found significant relationships between environmental characteristics (e.g., number of destinations, aesthetics) and physical activity. While a few of these studies verified that the physical activities assessed were performed in the environments examined, none have done this in an urban, neighborhood setting. This information will help efforts to inform policy decisions regarding the design of more "physically active" communities. Fourteen environmental characteristics of 60, 305-m-long segments, located in an urban, residential setting, were directly measured using standardized procedures. The number of individuals walking, jogging, and biking in the segments was assessed using an observation technique. The segments were heterogeneous with regards to several of the environmental characteristics. A total of 473 individuals were seen walking, bicycling, or jogging in the segments during 3,600 min of observation (60 min/segment). Of the 473 seen, 315 were walking, 116 bicycling, and 42 jogging. A greater number of individuals were seen walking in segments with more traffic, sidewalk defects, graffiti, and litter and less desirable property aesthetics. Only one environmental characteristic was associated with bicycling and none were significantly related with jogging. This study provides further evidence that environmental characteristics and walking are related. It also adds new information regarding the importance of scale (e.g., micro, macro) and how some environmental characteristics of urban, residential sidewalks and streets relate to physical activity.

Influence of Carbohydrate Ingestion on Oxidative Stress and Plasma Antioxidant Potential Following a 3 h Run

Concentrations of reactive oxygen species (ROS) increase during exercise secondary to increased oxygen uptake, xanthine oxidase activity, and immune system activation. Carbohydrate compared to placebo beverage ingestion is associated with an attenuated cortisol and catecholamine response. Catecholamines can undergo autooxidation to form ROS. We hypothesized that during intense exercise, ingestion of carbohydrate compared to placebo would diminish oxidative stress. Sixteen experienced marathoners ran on treadmills for 3 h at approximately 70% VO2(max) on two occasions while receiving carbohydrate or placebo beverages (11/h, double-blinded) in a randomized, counterbalanced order. Blood samples were collected before and immediately after exercise, snap frozen in liquid nitrogen, and stored at -80 degrees C until analysis. Plasma samples were analyzed for F2-isoprostanes (FIP) and lipid hydroperoxides (ROOH) as measures for lipid peroxidation, ferric reducing ability of plasma (FRAP) as a measure of plasma antioxidant potential and for cortisol. The pattern of change in cortisol was significantly different between carbohydrate and placebo conditions (P = 0.024), with post-exercise levels higher in the placebo condition. Under both carbohydrate and placebo conditions, significant increases in FIP, ROOH, and FRAP were measured, but the pattern of increase was not different (FIP, interaction effect, P = 0.472; ROOH, P = 0.572; FRAP, P = 0.668). Despite an attenuation in the cortisol response, carbohydrate compared to placebo ingestion does not counter the increase in oxidative stress or modulate plasma antioxidant potential in athletes running 3 h at 70% VO2(max).

The effects of internal versus external information processing on symptom perception in an exercise setting

The purpose of our study was to determine the effects of internal versus external attentional focus on symptom perception and performance in an exercise setting. Fifteen introductory psychology undergraduates ran 1 mile under each of three experimental conditions: "word-cue," in which subjects were required to focus externally by listening for a target word heard repeatedly over headphones; "breathing," in which subjects were directed to attend to their own breathing and heart rate; and a control. Results indicated that participants reported significantly less symptomatology, particularly exercise-relevant symptoms, in the word-cue condition than in the breathing or control conditions. The findings are discussed with reference to previous theory in this area, and methodological differences between this and earlier research are delineated.

Different physical activity subtypes and risk of metabolic syndrome in middle-aged and older Chinese people

BACKGROUND

The prevalence of metabolic syndrome (MetS) is growing rapidly in China. Tai chi and dancing are common types of exercise among middle-aged and elderly Chinese. It remains unclear whether these activities are associated with a lower risk of MetS.

METHODOLOGY/PRINCIPAL FINDINGS

A total of 15,514 individuals (6,952 men, 8,562 women) aged 50 to 70 years from the Dongfeng-Tongji Cohort in Shiyan, China participated in a cross-sectional study. Physical activity and other lifestyle factors were assessed with semi-structured questionnaires during face-to-face interviews. MetS was defined by the current National Cholesterol Education Program/Adult treatment Panel III criteria for Asian Americans. The prevalence of MetS was 33.2% in the study population. In the multivariable-adjusted logistic regression analyses, total physical activity levels were monotonically associated with a lower odds of MetS [OR 0.75 comparing extreme quintiles, 95% confidence interval (CI) 0.66-0.86, P<0.001]. Compared with non-exercisers in a specific exercise type, jogging (OR 0.82, 95% CI 0.68-1.00, P = 0.046), tai chi (OR 0.72, 95% CI 0.60-0.88, P<0.001), and dancing (OR 0.56, 95% CI 0.47-0.67, P<0.001) were associated with significantly lower odds of MetS. Furthermore, each 1-h/week increment in tai chi and dancing was associated with a 5% (95% CI 2%-9%) and a 9% (95% CI 6%, 12%) lower risk of MetS.

CONCLUSIONS/SIGNIFICANCE

Jogging, tai chi and dancing are associated with a significantly lower risk of having MetS in middle-aged and older Chinese. Future intervention studies should consider the role of jogging, tai chi and dancing in preventing MetS.

Mood profiles of marathon runners, joggers and non-exercisers

10 marathon runners and 10 joggers reported less depression on an adjective check list than 10 non-exercisers, as well as less confusion, more vigor. Marathoners scored better on each than joggers.

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.

Comparative evaluation of chronotropic responses of QT sensing and activity sensing rate responsive pacemakers

The rate responses of activity sensing (ATS) and QT sensing (QTS) rate responsive pacemakers to different forms and durations of exercises were compared. Nine patients with ATS and five with QTS were studied. All had complete heart block and atrial arrhythmias. At the onset, the pacemakers were programmed to achieve a pacing rate of 100-110 bpm by the end of stage 1 of the Bruce protocol, and to a pacing rate range of 70-150 bpm. With progressive exercise, using a treadmill (Bruce protocol), the maximum pacing rates in the two groups were not significantly different (mean +/- SD: 123 +/- 18 vs 129 +/- 23 bpm, ATS vs QTS). The time taken to return to the baseline pacing rate during recovery was significantly longer with QTS (178 +/- 70 vs 264 +/- 68 s, p less than 0.05). Brief exercise tests on a treadmill were performed for 3 min each with different combinations of treadmill speeds (1.2 and 2.5 mph) and gradients (0, 5, 10 and 15%). In both groups of patients, faster walking speed was associated with a faster pacing rate at each gradient. However, with increasing gradients, at each speed, there was a rise in the maximum pacing rate only in patients with QTS. During brief exercise tests, the maximum rate was achieved by the end of exercise in patients with ATS, but was delayed by 33 +/- 20 s after exercise in patients with QTS.(ABSTRACT TRUNCATED AT 250 WORDS)

Smoking, alcohol consumption, and endurance capacity: an analysis of 6,500 19-year-old conscripts and 4,100 joggers

Using data from two Swiss studies, a 20% random sample (n = 6,592) of all 19-year-old army conscripts and all male participants in a 16-km popular race (n = 4,358), we studied the relationships among smoking, alcohol consumption, and endurance capacity using univariate and multivariate analyses. Alcohol was significantly correlated with endurance capacity among joggers in univariate analysis, but lost its significance in multivariate analysis. Among army conscripts, the distance covered in a 12-min endurance run was inversely related to daily cigarette consumption and years of smoking (P less than 0.001). This association was apparent even among light smokers who had been smoking for less than 2 years when they were compared with nonsmokers. Among joggers, even when the lower training activity of the smokers was controlled for, smoking retained a negative, independent association with endurance capacity, as measured by 16-km race time. In multiple regression analysis of endurance capacity, the standardized regression coefficient for smoking was -0.14 for distance covered in the 12-min run and 0.10 for 16-km running time, the latter despite the low prevalence (6.9%) of regular cigarette smokers among the joggers. Seventy percent of the 16-km race participants who smoked around the time they took up jogging quit smoking as joggers. Within the limits of this cross-sectional study design, these results suggest that smoking exerts a direct, biologically mediated, deleterious effect on endurance capacity. The lower levels of exercise of the smokers did not entirely explain the difference in endurance between smokers and nonsmokers. This observation of a short-term negative association between even light smoking and endurance capacity may have implications for health education and promotion efforts.

Osteochondritis of the hallux sesamoid bones

The clinical, radiological, and pathological features of six cases of osteochondritis of the metatarsal sesamoids are presented. This condition seems to affect primarily young females. Bone scans are a useful tool in assessing disease in the hallux sesamoid bones. Stress fracture and subsequent repair are postulated as the etiology of osteochondritis of the hallux sesamoid bones. Many of these cases do not respond to conservative management and the affected sesamoid must be surgically removed.

Concurrent myocardial and cerebral infarctions after intranasal cocaine use

BACKGROUND AND PURPOSE

Cardiac and cerebrovascular complications associated with cocaine abuse have increasingly been reported, but concurrent development of cocaine-induced cardiac disease and stroke has rarely been reported.

CASE DESCRIPTION

A 37-year-old man with a remote history of intravenous heroin and amphetamine use, cardiomyopathy, and recent cocaine use developed chest pain and ventricular tachycardia 30 minutes after intranasal cocaine hydrochloride use and jogging on a cold winter morning. Ventricular tachycardia was converted to atrial fibrillation. He was proven to have a small myocardial infarction. Within 6 hours of cocaine use he suffered a left hemisphere stroke. Cardiac electrophysiologic evaluation revealed inducible ventricular tachycardia.

CONCLUSIONS

To our knowledge, this is the first report of concurrent myocardial infarction, life-threatening ventricular arrhythmias, and cerebral infarction temporally related to cocaine use. It is probable that one mechanism by which cocaine use causes stroke is to trigger expression of a known cardiac source of embolism.

Serum lipoproteins, sex hormones and sex hormone binding globulin in middle-aged men of different physical fitness and risk of coronary heart disease

Serum concentrations of lipoproteins, apolipoprotein A-I (Apo A-I), androgens, including biologically active free testosterone (free T), and sex hormone binding globulin (SHBG) and their associations were studied in 3 groups of men of different physical fitness and risk of CHD, consisting of male CHD patients, joggers and healthy controls. Of the 3 study groups, men with angiographically assessed CHD had the lowest HDL-C (P less than 0.002) and highest LDL-C and triglyceride (TG) levels (P = 0.05 and P less than 0.001) and lower 5 alpha-dihydrotestosterone (5 alpha-DHT) levels than joggers (P less than 0.02). Joggers had the highest serum high density lipoprotein cholesterol (HDL-C), Apo A-I and SHBG levels and lowest serum low density lipoprotein cholesterol (LDL-C) compared to the other groups (P less than 0.01). In correlation analysis 5 alpha-DHT was the most significant positive determinant of HDL-C and Apo A-I levels in CHD patients (r = 0.56 and r = 0.55, respectively, P less than 0.05). Moreover, SHBG was significantly positively correlated to both HDL-C and Apo A-I levels in patients, in the whole study group and in healthy men separately (r = 0.37-0.52, P less than 0.01). These significant correlations were also confirmed when age variation and differences in body mass index and smoking were controlled in multivariate analysis and in addition, in multivariate analysis both serum free and total testosterone were inversely related to serum triglyceride (TG) levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Physical fitness. Its contribution to serum high density lipoprotein

The effects of exercise conditioning on serum high density lipoprotein cholesterol (HDL-C) were studied using 20 members of a regular joggers club and other healthy non-member subjects of varying degrees of habitual physical activity (253 males and 391 females). Both the HDL-C and HDL-C/serum total cholesterol (TC) levels were significantly higher with the 20 regular joggers than with the sedentary controls matched for age, TC, serum triglycerides (TG) and weight index (WI). A significant correlation was found between HDL-C/TC and the exercise conditioning value obtained by using the results of the 12-min performance test as an index among the non-member subjects. In order to ascertain the relative significance of exercise conditioning in influencing HDL-C/TC, a multiple regression analysis was conducted using HDL-C/TC as the variable criterion. The results showed that TG affected HDL-C/TC the most among both males and females, while exercise conditioning affected it second among males and fourth among females.

Effects of self-monitored jogging on physical fitness, blood pressure and serum lipids: a controlled study in sedentary middle-aged men

To study the effects of long-term, home-based exercise on physical fitness and cardiovascular risk factors of middle-aged nonsmoking males, a controlled study was conducted in 61 sedentary Swiss men. Thirty-nine men were randomly allocated to jog 2 h/week for 4 months on an individually prescribed and heart-rate-controlled basis, whereas 22 men served as controls. Despite varying adherence to the exercise regimen, the 4-month net change (effect in exercise group minus effect in control group) in estimated endurance capacity was significant and positive. Net changes in arterial blood pressure, measured with a random-zero device, were nonsignificant, but after exclusion of low-normotensive men (n = 19) from analysis, a significant net effect of exercise on diastolic blood pressure was seen (-4.3 mmHg; p = .048). The following net changes in serum lipid levels occurred: HDL cholesterol + 0.12 mmol/l (p = .028), total triglycerides -0.21 mmol/l (ns), HDL-C/total cholesterol ratio +0.02 (p = .047). Exploratory analyses revealed that an increase in estimated endurance capacity was associated with a rise in systolic and diastolic blood pressure (r = 0.49 and 0.43, respectively; p less than 0.01 both). Changes in the waist-hip ratio were directly related to the change in diastolic blood pressure (r = 0.27; p less than 0.05). Multivariable analysis indicated that much of the beneficial effect of exercise on diastolic blood pressure was apparently mediated through a decrease in body fat. This study confirms that individually prescribed jogging can reduce cardiovascular risk factors in self-selected nonsmoking males.(ABSTRACT TRUNCATED AT 250 WORDS)

Jog-walk training in cardiorespiratory fitness of adults with Down syndrome

The purpose of this study was to evaluate the effects of an aerobic training program on adults with Down syndrome. 25 male adults with Down syndrome (M age = 24.6 yr., [Qs = 45-60) participated in a 12-wk. exercise training study. Subjects were assigned to an experimental group (n = 15) and a control group (n = 10). Pre- and posttraining treadmill tests were performed to determine the following peak physiological parameters: heart rate (HR peak), peak minute ventilation (V(E) peak), peak oxygen consumption (VO2 peak, absolute and relative), and time to exhaustion (min.). The experimental group underwent a 12-wk. interval training program. The control group received no structured exercise training during this period. Following the 12-wk. training program, significant improvements (p < .05) in peak physiological parameters were seen for the experimental group for VO2 peak (both relative and absolute). V(E) peak, and time to exhaustion. No significant improvements in peak physiologic parameters were seen in the control group. Consistent with prior research using similar subjects, we concluded that adults with Down syndrome are able to improve their aerobic capacity when performing a systematic and well-designed aerobic training program.

Relationship of skeletal muscle fiber type to serum high density lipoprotein cholesterol and apolipoprotein A-I levels

We measured the percentage of slow-twitch (ST) muscle fibers in the lateral portion of the quadriceps femoris muscle in 41 healthy sedentary male controls, 35 active male joggers, and 26 male coronary heart disease (CHD) patients. We then compared these percentages with serum levels of total cholesterol (TC), triglycerides (TG), high density lipoprotein cholesterol (HDL-C) and apolipoprotein A-I (apo A-I) found in these 102 middle-aged men. The percentage of ST muscle fibers in all men correlated positively with serum HDL-C (r = 0.57, P less than 0.001) and with apo A-I (r = 0.60, P less than 0.001) and negatively with triglycerides (r = -0.43, P less than 0.001). The proportion of ST fibers in joggers (65%; 61-69%, 95% confidence interval) was higher (P less than 0.001) than in sedentary controls (48%; 44-52%) or in CHD patients (44%; 39-49%). Moreover, 89% of the joggers had a proportion of ST fibers higher than 50%, whilst in sedentary controls and in CHD patients these values were 46% and 38%, respectively. Positive correlations were found between the percentage of ST fibers and both HDL-C and apo A-I in controls (r = 0.33, P less than 0.05 and r = 0.34, P less than 0.05) and in joggers (r = 0.46, P less than 0.01, and r = 0.40, P less than 0.05), respectively. Negative correlations in controls (r = -0.34, P less than 0.05) and in CHD patients (r = -0.43, P less than 0.05) were also found between the percentage of ST fibers and serum TG.(ABSTRACT TRUNCATED AT 250 WORDS)

Psychological effects of jogging: a preliminary study

Three chronic psychiatric patients in a halfway house were enrolled in a program of regular supervised jogging. In comparison with three other chronic patients from the same setting who received the same amount of attention but no jogging, the jogging group showed significantly less posttest trait anxiety. No significant posttest differences in body image were found between groups. The role of multi-process relaxation is discussed.

Tear of the biceps femoris tendon

The clinical and operative findings of an isolated rupture of the biceps femoris tendon are described. The immediate suture and the initial postoperative treatment with a knee brace limiting extension to 20 degrees and flexion to 70 degrees resulted in a free range of motion and full activity of the biceps femoris.

Effects of physical activity on bone mineral content and muscle strength in women: a cross-sectional study

Physical exercise is known to increase bone mass in men, whereas the effect is less predictable in women. In this cross-sectional report, effects of physical activity on women aged 38-64 years are studied. Bone mass and muscle strength were compared between 30 regularly exercising women jogging only once a week for at least three years and an equal number of controls matched for age. BMC of the distal third of the radius was significantly higher in the active women. The active women over age 50 also had higher trabecular bone mass in the distal end of the radius. Quadriceps strength and balance were also found to be better in the activity group. Active women had a different lifestyle than the non-active women, with less consumption of alcohol, oestrogens, and tobacco. This report supports the hypothesis that regular moderate physical activity might reduce bone loss in women.

Physical activity and risk of neural tube defects

OBJECTIVE

Owing to its association with known risk factors for neural tube defects (NTDs) and its impact on physiologic processes relevant to fetal development, physical activity was identified as a potential risk factor for NTD-affected pregnancy.

METHODS

Using data from a population-based case-control study of deliveries occurring in California from 1989 to 1991, we estimated the potential risk of having an NTD-affected pregnancy associated with variation in maternal physical activity. In-person interviews were conducted with 538 (88% of eligible) mothers of NTD cases and with mothers of 539 (88%) nonmalformed controls on average 5 months from the term delivery date. An index reflecting reported frequency and exertion level for six activity groups (e.g., jogging and running) was used to summarize each woman's physical activity level in the periconceptional period.

RESULTS

Unadjusted analyses indicated that compared to women considered inactive by this index, physically active women had 30-50% lower risk for NTD-affected pregnancies. After adjustment for several potential confounders and an evaluation of potential effect modification, results suggested that the association was restricted to women who did not take multivitamin/mineral supplements during the periconceptional period. Excluding mothers with reported medical problems did not substantially alter findings.

CONCLUSIONS

This study suggests that the benefits of physical activity may extend to reduction of NTD risk among certain subgroups of women.

Performance assessment of the Terry Fox jogging prosthesis for above-knee amputees

The Terry Fox jogging (TFJ) prosthesis was developed at Chedoke-McMaster Hospital to alleviate the asymmetric jogging pattern experienced by above-knee amputees when attempting to jog with conventional walking prostheses. This prosthesis features a spring-loaded, telescoping shank designed to eliminate any vaulting action and control the trunk motion during stance. The spring is intended to attenuate the impact forces and release its stored energy at push-off to provide momentum transfer to the jogger. This prosthesis was comprehensively assessed in the gait laboratory, by evaluating the kinematics, energy and power flow patterns of an above-knee amputee jogger wearing the TFJ prosthesis. Included in the assessment is the ability of the prosthesis to satisfy a set of relevant design criteria that have been established from non-amputee jogging patterns. An increased swing phase time for the prosthetic limb and the need to have the knee hyperextended throughout the stance phase contributed to an asymmetric jogging style. The telescoping action did lower the amputee's centre of mass, thereby reducing the vaulting effect. However, the spring only imparted a lifting action to the jogger and the ground reaction forces were double those of a non-amputee jogger. These findings clearly indicate a need to redesign the TFJ prosthesis and are being incorporated in the design of a new physiological jogging prosthesis.