Asthma is characterized by excessive airway narrowing and airway wall inflammation. In cases of fatal asthma, increased thickness of the airway wall is observed and may account for excessive airway narrowing when smooth muscle contracts. This study was undertaken to examine airway dimensions in large and small airways in both fatal and nonfatal cases of asthma. Airway wall areas (total, inner, and outer relative to smooth muscle layer), epithelial integrity, smooth muscle shortening, and the areas of smooth muscle, cartilage, and mucous glands were compared in transverse sections of large and small airways of subjects dying of asthma (fatal asthma, n = 11), those dying suddenly of nonrespiratory diseases and having a definite history of asthma (nonfatal asthma, n = 13), and those dying suddenly without any history of respiratory illness (control, n = 11). Airways were grouped by size using the basement membrane perimeter for comparison. All areas were expressed as areas per millimeter of basement membrane. In cartilaginous airways, the cases of fatal asthma had greater (p < 0.05) total wall, inner wall, outer wall, smooth muscle, mucous gland and cartilage areas than did control and nonfatal cases. The inner wall area was greater in the fatal and nonfatal cases than in the control cases (p < 0.05) in the small cartilaginous airways and membranous bronchioles (MB). In small MB (perimeter < 2 mm), the total and outer wall areas were greater (p < 0.05) in cases of fatal and nonfatal asthma than in control cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Overtraining appears to be caused by too much high intensity training and/or too little regeneration (recovery) time often combined with other training and nontraining stressors. There are a multitude of symptoms of overtraining, the expression of which vary depending upon the athlete's physical and physiological makeup, type of exercise undertaken and other factors. The aetiology of overtraining may therefore be different in different people suggesting the need to be aware of a wide variety of parameters as markers of overtraining. At present there is no one single diagnostic test that can define overtraining. The recognition of overtraining requires the identification of stress indicators which do not return to baseline following a period of regeneration. Possible indicators include an imbalance of the neuroendocrine system, suppression of the immune system, indicators of muscle damage, depressed muscle glycogen reserves, deteriorating aerobic, ventilatory and cardiac efficiency, a depressed psychological profile, and poor performance in sport specific tests, e.g. time trials. Screening for changes in parameters indicative of overtraining needs to be a routine component of the training programme and must be incorporated into the programme in such a way that the short term fatigue associated with overload training is not confused with the chronic fatigue characteristic of overtraining. An in-depth knowledge of periodisation of training theory may be necessary to promote optimal performance improvements, prevent overtraining, and develop a system for incorporating a screening system into the training programme. Screening for overtraining and performance improvements must occur at the culmination of regeneration periods.

It is considered that skeletal mass in humans may respond to loading or the number of loading cycles. The aim of this study was to examine the effect of a 1 year progressive resistance training program on the bone mass of 56 postmenopausal women. Assignment was by block randomization to one of two resistance training groups: a strength trained group (3 x 8 repetition maximum) or an endurance group (3 x 20 repetition maximum). The resistance exercises were selected to stress the ipsilateral forearm and hip region. The exercising side was randomly assigned with one side exercised while the alternate side acted as the nonexercise control. Bone mineral density (BMD) was measured every 3 months at the radial forearm and four hip sites using the Hologic QDR 2000 bone densitometer. A linear regression function was fitted for each individual's bone density results, and the slope was compared for the exercise and control side using paired t-tests. The bone mass increase with the strength regimen was significantly greater at the trochanteric hip site (control -0.6 +/- 2.2%, exercise 1.7 +/- 4.1%, p < 0.01), at the intertrochanteric hip site (control -0.1 +/- 2.1%, exercise 1.5 +/- 3.0%, p < 0.05), Ward's triangle (control 0.8 +/- 5.2%, exercise 2.3 +/- 4.0%, p < 0.05), and at the ultradistal radial site (control -1.4 +/- 2.3%, exercise 2.4 +/- 4.3%, p < 0.01). There was no significant increase in BMD with the endurance regimen except at the radius midsite (control -1.0 +/- 2.3%, exercise 0.1 +/- 1.4%, p < 0.01). In both the endurance and the strength group, muscle strength, tested by a one-repetition maximum (1RM) test, increased significantly for all 10 exercises (p < 0.01) and to a similar degree in the two groups. In the strength group but not the endurance group there were significant correlations between the slope of the change in BMD and the percentage increase in strength as follows: trochanter with leg press; intertrochanter with leg press (p < 0.05); and Ward's triangle with hip extension and hip adduction (p < 0.05). Thus these results support the notion of a site-specific response of bone to maximal loading from resistance exercise in that although the trochanter and intertrochanter bone density was elevated by the resistance exercises undertaken, there was no effect on the femoral neck value. Postmenopausal bone mass can be significantly increased by a strength regimen that uses high-load low repetitions but not by an endurance regimen that uses low-load high repetitions. We conclude that the peak load is more important than the number of loading cycles in increasing bone mass in early postmenopausal women.

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Objective: To investigate whether 12 weeks of graded exercise with pacing would improve specific physiological, psychological and cognitive functions in people with chronic fatigue syndrome (CFS). Design: Randomised controlled trial. Setting: Human performance laboratory at the University of Western Australia. Participants: 61 patients aged between 16 and 74 years diagnosed with CFS. Interventions: Either graded exercise with pacing (32 patients) or relaxation/flexibility therapy (29 patients) performed twice a day over 12 weeks. Main outcome measures: Changes in any of the physiological, psychological or cognitive variables assessed. Results: Following the graded exercise intervention, scores were improved for resting systolic blood pressure (P = 0.018), work capacity (W·kg‐1) (P = 0.019), net blood lactate production (P = 0.036), depression (P = 0.027) and performance on a modified Stroop Colour Word test (P = 0.029). Rating of perceived exertion scores, associated with an exercise test, was lower after graded exercise (P = 0.013). No such changes were observed in the relaxation/flexibility condition, which served as an attention‐placebo control. Conclusions: Graded exercise was associated with improvements in physical work capacity, as well as in specific psychological and cognitive variables. Improvements may be associated with the abandonment of avoidance behaviours.

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Understanding the stress/strain relationship between exercise and bone is critical to understanding the potential benefit of exercise in preventing postmenopausal bone loss. This study examined the effect of a 2-year exercise intervention and calcium supplementation (600 mg) on bone mineral density (BMD) in 126 postmenopausal women (mean age, 60 ؎ 5 years). Assignment was by block randomization to one of three groups: strength (S), fitness (F), or nonexercise control (C). The two exercise groups completed three sets of the same nine exercises, three times a week. The S group increased the loading, while the F group had additional stationary bicycle riding with minimal increase in loading. Retention at 2 years was 71% (59% in the S group, 69% in the F group, and 83% in the C group), while the exercise compliance did not differ between the exercise groups (S group, 74 ؎ 13%; F group, 77 ؎ 14%). BMD was measured at the hip, lumbar spine, and forearm sites every 6 months using a Hologic 4500. Whole body BMD also was measured every 6 months on a Hologic 2000. There was no difference between the groups at the forearm, lumbar spine, or whole body sites. There was a significant effect of the strength program at the total (0.9 ؎ 2.6%; p < 0.05) and intertrochanter hip site (1.1 ؎ 3.0%; p < 0.01). There was a significant time and group interaction (p < 0.05) at the intertrochanter site by repeated measures. This study shows the effectiveness of a progressive strength program in increasing bone density at the clinically important hip site. We concluded that a strength program could be recommended as an adjunct lifestyle approach to osteoporosis treatment or used in combination with other therapies. (J Bone Miner Res 2001;16:175-181)