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.

Endothelin-1 concentration in plasma is increased after jogging but decreased after cycling in healthy men

Endothelin-1 plays an important role as a paracrine factor in the regulation of regional blood flow. Plasma levels may represent the net result of spill-over from local stimulation/release and elimination of endothelin-1. In order to compare changes in the concentration of endothelin-1 in the plasma of subjects performing different types of sports exercises we measured immunoreactive endothelin-1 in healthy volunteers ( n=20) performing in random order jogging on a treadmill and cycling on a bicycle ergometer, for 30 min each. Plasma immunoreactive endothelin-1 increased significantly after jogging (2.13+/-0.8 pg/ml versus 2.6+/-0.8 pg/ml, before and after exercise, respectively, P<0.03), whereas it decreased after cycling (2.45+/-0.76 pg/ml versus 2.25+/-0.9 pg/ml, before and after exercise, respectively, P<0.03). We suggest that microtraumatizing effects on the endothelial lining are more pronounced during jogging than during cycling, resulting in a greater increase in plasma endothelin-1, which is too high to be immediately eliminated by the lung despite exercise-induced enhanced pulmonary perfusion. In contrast, similarly enhanced lung perfusion together with a relatively lower stimulation of endothelin-1 compared with jogging, may explain the net decrease in plasma after cycling.

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.

Effects of approach velocity and foot-target characteristics on the visual regulation of step length

Two questions emerge from the literature concerning the perceptual-motor processes underlying the visual regulation of step length. The first concerns the effects of velocity on the onset of visual control (VCO), when visual regulation of step length begins during goal-directed locomotion. The second concerns the effects of different obstacles such as a target or raised surface on step length regulation. In two separate experiments, participants (Experiment 1 & 2: n=12, 6 female, 6 male) walked, jogged, or sprinted towards an obstacle along a 10 m walkway, consisting of two marker-strips with alternating black and white 0.50 m markings. Each experiment consisted of three targeting or obstacle tasks with the requirement to both negotiate and continue moving (run-through) through the target. Five trials were conducted for each task and approach speed, with trials block randomised between the six participants of each gender. One 50 Hz video camera panned and filmed each trial from an elevated position, adjacent to the walkway. Video footage was digitized to deduce the gait characteristics. Results for the targeting tasks indicate a linear relationship between approach velocity and accuracy of final foot placement (r=0.89). When foot placement was highly constrained by the obstacle step length shortened during the entire approach. VCO was found to occur at an earlier tau-margin for lower approach velocities for both experiments, indicating that the optical variable 'tau' is affected by approach velocity. A three-phase kinematic profile was found for all tasks, except for the take-off board condition when sprinting. Further research is needed to determine whether this velocity affect on VCO is due to 'whole-body' approach velocity or whether it is a function of the differences between gait modes.

[Joggers live longer. The Osterbro study]

INTRODUCTION

Jogging is one of the most popular forms of vigorous exercise, but its effect on longevity has not been documented.

METHOD

This analysis comprise a random sample of 4658 men aged 20-79 years with no prior myocardial infarction, who participated in the first (1976-1978) and second (1981-1983) examination of the Copenhagen City Heart Study. They were entered in the mortality analysis at the second examination and were followed up until 30 November 1998. The influence of jogging on time to death was analysed by Cox regression, with age as the time axis. In addition to jogging, the model included diabetes, smoking, household income, education, and alcohol consumption as potential confounding variables, and systolic blood pressure, total cholesterol, HDL cholesterol, and BMI as intermediate variables.

RESULTS

At the first examination, 217 men (4.7%) reported active jogging. Of these, 96 (2.1%) were still joggers five years later. Overall, 4335 men were non-joggers at both examinations. A significant effect of jogging was found only for the group that were joggers at both examinations, relative risk 0.37 (95% confidence interval, 0.19 to 0.71; p = 0.003).

DISCUSSION

We have found that regular joggers have a significantly lower mortality than have non-joggers. This could also be due to other lifestyle factors, but numerous studies have pointed towards a beneficial effect of physical activity on health. The optimal intensity, frequency, and duration of physical activity has yet to be established.

Patients with fibromyalgia benefit from aerobic endurance exercise

Fibromyalgia (FM) is a disorder characterised by diffuse widespread musculoskeletal aching and stiffness and multiple tender points [1]. Its pathophysiology is poorly understood. The influence of aerobic endurance exercise on pain in patients with FM was investigated. Twenty-seven patients (25 female, 2 male) participated in a controlled clinical study and performed 12 weeks of jogging, walking, cycling or swimming following a given schedule. Twelve sedentary FM patients (11 female, 1 male) served as controls. Before and after training both the study and the control groups were evaluated spiroergometrically. Tender point pain was quantified by dolorimetry. The painful body surface was estimated by a pain body diagram, and its intensity by a visual analogue scale and a ranking scale. Patients trained for an average of 25 min two to three times a week, with an average intensity of 50% of maximal oxygen uptake (VO2max). Unlike the control group, the training group exhibited a decrease in heart rate and VO2 and an increase in respiratory quotient during submaximal workload. Maximal performance capacity and VO2max remained unchanged, whereas the wattpulse (watt/heart rate) improved at maximal workload. Pain parameters remained unchanged in the control group, but in the training group the mean number of positive tender points (15.4/12.7), the mean pain threshold of the gluteal tender point (2.89 kp/3.50 kp) and the painful body surface (18%/15% body surface) decreased significantly. Subjective general pain condition deteriorated in two patients but improved in 17. Our results suggest a positive effect of aerobic endurance exercise on fitness and well-being in patients with FM.

[Knee endoprosthesis: sports orthopedics possibilities and limitations]

Many patients would like to resume some sport activities after total knee replacement; however, most recommendations are based on subjective opinion rather than scientific evidence. The following paper presents a literature review of sports after total knee replacement and includes recommendations which are based on biomechanical laws. Most total knee designs show increased conformity near full extension. Beyond a certain knee flexion angle, the conformity ratio decreases due to a reduced femoral radius. Therefore, these designs accept higher loads near full extension than in flexion. In order to recommend suitable physical activities after total knee replacement, both the load and the knee flexion angle of the peak load must be considered. It has been shown that power walking and cycling produce the lowest polyethylene inlay stress of a total knee replacement and seem to be the least demanding endurance activities. Jogging and downhill walking show high inlay stress levels and should be avoided. Hence, for mountain hiking, patients are advised to avoid descents or at least use skipoles and walk slowly downhill to reduce the load on the knee joint. It must also be mentioned that any activity represents additional wear, which may affect the long-term results of total knee replacements. Further clinical studies are necessary to validate the biomechanical investigations.

PET studies of the effects of aerobic exercise on human striatal dopamine release

In vivo microdialysis studies have shown that exercise increases the concentration of dopamine (DA) in the striatum of the rat brain. It has also been shown that PET with [11C]raclopride can be used to assess changes in brain DA induced by drugs and by performance tasks such as playing a video game. The purpose of this study was to evaluate the effects of exercise (treadmill running) on striatal DA release in the human brain.

METHODS

Twelve healthy volunteers (5 women, 7 men; mean age, 32 +/- 5 y; age range, 25-40 y) with a history of regular exercise received 2 PET scans with [11C]raclopride on 2 separate days, 1 at baseline and 1 at 5-10 min after running on a treadmill for 30 min. The speed and inclination of the treadmill were increased gradually to reach a maximal speed of 9.7 km/h (6 mph) and a maximal inclination of 10degrees. Data were acquired on a Siemens HR+ scanner in 3-dimensional mode for 60 min. Heart rates and electrocardiograms were monitored. DA D2 receptor availability was measured using the ratio of the distribution volume in the putamen to that in the cerebellum, which is a function of the number of available binding sites/dissociation constant.

RESULTS

The subjects ran at an average speed of 8.7 +/- 0.5 km/h (5.4 +/- 0.3 mph) and at an inclination of 3.3degrees +/- 2degrees. The maximum effort of running was maintained for 10-15 min. The heart rates of the subjects were increased by 143% +/- 47%. DA D2 receptor availability in the putamen after treadmill running (4.22 +/- 0.34) was no different from that of baseline (4.17 +/- 0.29; P < 0.6).

CONCLUSION

No significant changes in synaptic DA concentration were detected, although the subjects exercised vigorously for 30 min.

The effect of jogging on P300 event related potentials

Physical exercise has beneficial effects not only on cardiovascular system and fat metabolism, may also directly effect the cognitive process. We studied the effect of physical exercise on cognitive processes by measuring the P300 event related-potential (ERP) after jogging. Seven well-trained joggers were enrolled in this study and the P300 potentials using auditory oddball paradigm. ERPs were measured before and after 30 minutes of jogging. The amplitude of the P300 significantly increased after jogging compared to values recorded before jogging. These findings suggest that jogging has the effect of facilitating cognitive processes involved in generation of the P300.

Primary and secondary reinforcers in performance of a 1.0-mile walk/jog by adolescents with moderate mental retardation

Based on visual inspection of data, reinforcement procedures, namely, use of verbal praise and verbal praise plus token exchange, were at least mildly influential in improving performance of 5 youth with moderate mental retardation compared to their initial performance without reinforcers. These findings suggest specific reinforcement may improve the time for aerobic activity by adolescents with moderate mental retardation.

Further evaluation of physical fitness age versus physiological age in women

The present study was conducted to examine further whether adult women who are in a state of high physical fitness possess high physiological functions, and also to investigate whether those who exercise regularly are able to maintain a high quality of various physiological functions. The subjects of this study were 249 healthy Japanese adult women (aged 20-70 years). Of these subjects 30 had jogged or walked regularly for more than 3 years. The physiological ages (PA) and physical fitness ages (FA) of the individuals were estimated from 17 physiological function tests and 5 physical fitness tests, respectively, by principal components analyses. The results indicated that there was a significant correlation between PA and FA (r = 0.76, P < 0.01). To examine this relationship in more detail, the subjects were classified into three physical fitness groups (high, normal and low) based on the deviation from the regression line of FA. Comparison of the mean PA among three physical fitness groups revealed that the high physical fitness groups demonstrated a much lower PA (physiologically younger), while the low physical fitness groups showed a relatively higher PA (physiologically older) in spite of their equivalent chronological ages. From this series of studies, a new concept is proposed where different individuals have different peak physiological capacities, but that these capacities change with age at similar rates. It is suggested that interventions such as exercise and a proper diet for promoting health could increase peak functional capacity but have little effect on the rate of decline.

[Aqua-jogging in the rehabilitation process]

Aquajogging consists of simulated running in deep water aided by a flotation device (vest or belt) that maintains the head above water. In sports, Aquajogging is used as a training for regeneration or a low impact training alternative. In rehabilitation Aquajogging is well used in rheumatology diseases, in the pre- and postoperative management of musculoskeletal diseases and in endurance and power training in cardiorespiratory diseases.

Exercise and smoking habits among Swedish postmenopausal women

OBJECTIVE

To assess exercise habits and their relation to smoking habits and social and medical factors in postmenopausal women.

METHODS

A cross-sectional study with a questionnaire to all 1324 55-56 year old women in Linköping, Sweden.

RESULTS

Response rate was 85%. About a third of the women took part in some kind of quite strenuous exercise for at least one hour a week. After a quarter worked out once a week; fewer did swimming and jogging. One in four women smoked. Women who used hormone replacement therapy, who were not smoking and who had a physically light occupation more often took part in strenuous sports. Women who had been treated for malignancies or with back problems exercised to the same extent as women in the general population.

CONCLUSION

About a third of the post-menopausal women exercised on a regular basis, if exercise involved in getting to and from work was not counted. Since regular physical exercise has many health benefits, more women should be encouraged to take part in regular physical exercise. Factors probably associated with level of education and general awareness of the importance of a healthy lifestyle positively influenced the likelihood of these women to be physically active on a regular basis. A previous malignant disease or current back problems did not prevent women from taking part in exercise on a regular basis.