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Pulmonary diffusing capacity (DICO), together with spirometric variables, arterial oxygen tension (paO2) and cardiac output were determined before and at intervals after maximal arm cranking, treadmill running and ergometer rowing. Independent of the type of exercise, D1CO increased immediately post-exercise from a median 13.6 (range 7.3-16.3) to 15.1 (9.3-19.6) mmol min-1 kPa-1 (P < 0.01). However, it decreased to 11.6 (6.9-15.5) mmol min-1 kPa-1 (P < 0.01) after 24 h with cardiac output and paO2 at resting values, and D1CO normalized after 20 h. Thoracic electrical impedance at 2.5 and 100 kHz increased slightly post-exercise, indicating a decrease in thoracic fluid balance, and there were no echocardiographic signs of left ventricular failure at the time of the decrease in D1CO. Also, active muscle (limb) circumference and volume, and an increase in haematocrit from 43.8 (38.0-47.0) to 47.1 (42.7-49.8) (P < 0.01), had normalized at the time of the decrease in D1CO. Vital capacity, forced vital capacity, forced expiratory volume in 1 s, peak and peak mid-expiratory flows did not change. However, total lung capacity increased from 6.8 (5.0-7.6) to 7.0 (5.1-7.8) litres (P < 0.05) immediately after exercise and remained elevated at 6.9 (5.1-8.7) litres (P < 0.05) when a decrease in D1CO was noted. The results demonstrate that independent of the type of maximal exercise, an approximate 15% reduction in D1CO takes place 2-3 h post-exercise, which normalizes during the following day of recovery.  相似文献   
2.
Abstract

Pulmonary diffusing capacity (Dlco), together with spirometric variables, arterial oxygen tension (paO2) and cardiac output were determined before and at intervals after maximal arm cranking, treadmill running and erogmeter rowing. Independent of the type of exercise, Dlco increased immediately post‐exercise from a median 13.6 (range 7.3–16.3) to 15.1 (9.3–19.6) mmol min‐1 kPa‐1 (P <0.01). However, it decreased to 11.6 (6.9–15.5) mmol min‐1 kPa‐1 (P <0.01) after 24 h with cardiac output and paO2 at resting values, and Dlco normalized after 20 h. Thoracic electrical impedance at 2.5 and 100 kHz increased slightly post‐exercise, indicating a decrease in thoracic fluid balance, and there were no echocardiographic signs of left ventricular failure at the time of the decrease in Dlco. Also, active muscle (limb) circumference and volume, and an increase in haematocrit from 43.8 (38.0–47.0) to 47.1 (42.7–49.8) (P <0.01), had normalized at the time of the decrease in Dlco. Vital capacity, forced vital capacity, forced expiratory volume in 1 s, peak and peak mid‐expiratory flows did not change. However, total lung capacity increased from 6.8 (5.0–7.6) to 7.0 (5.1–7.8) litres (P <0.05) immediately after exercise and remained elevated at 6.9 (5.1–8.7) litres (P <0.05) when a decrease in Dlco was noted. The results demonstrate that independent of the type of maximal exercise, an approximate 15% reduction in Dlco takes place 2–3 h post‐exercise, which normalizes during the following day of recovery.  相似文献   
3.
Reduced hepatic lactate elimination initiates blood lactate accumulation during incremental exercise. In this study, we wished to determine whether renal lactate elimination contributes to the initiation of blood lactate accumulation. The renal arterial-to-venous (a-v) lactate difference was determined in nine men during sodium lactate infusion to enhance the evaluation (0.5 mol x L(-1) at 16 ± 1 mL x min(-1); mean ± s) both at rest and during cycling exercise (heart rate 139 ± 5 beats x min(-1)). The renal release of erythropoietin was used to detect kidney tissue ischaemia. At rest, the a-v O(2) (CaO(2)-CvO(2)) and lactate concentration differences were 0.8 ± 0.2 and 0.02 ± 0.02 mmol x L(-1), respectively. During exercise, arterial lactate and CaO(2)-CvO(2) increased to 7.1 ± 1.1 and 2.6 ± 0.8 mmol x L(-1), respectively (P < 0.05), indicating a -70% reduction of renal blood flow with no significant change in the renal venous erythropoietin concentration (0.8 ± 1.4 U x L(-1)). The a-v lactate concentration difference increased to 0.5 ± 0.8 mmol x L(-1), indicating similar lactate elimination as at rest. In conclusion, a -70% reduction in renal blood flow does not provoke critical renal ischaemia, and renal lactate elimination is maintained. Thus, kidney lactate elimination is unlikely to contribute to the initial blood lactate accumulation during progressive exercise.  相似文献   
4.
Using Bourdieu’s notion of field, the Scandinavian field of maths pedagogy occurs at a time characterised by increasing inclusion efforts in primary school. Various stakeholders in maths pedagogy are arguing about what should be done about pupils who perform poorly in mathematics and what causes their difficulties. Four analytical positions are presented here: the diagnostic, the structural, the interventionist and the complementary. The literature examined includes academic articles on math pedagogy and scholarly journals for maths teachers from the period 1995–2014. A total of 103 articles were analysed. The results show that a context-oriented rationale dominates, but that a less prevalent, competing rationale emphasising individual causal explanations, is also present. I argue that the structure of the field is changing because of external influences that may affect the organisation of support for poorly performing pupils.  相似文献   
5.
Exhaustive exercise is associated with a persistent sensation of weakness and sometimes nausea suggesting abdominal vagal activity. We measured plasma indices of sympathoadrenal (adrenaline, noradrenaline, dopamine) and vagal (pancreatic polypeptide) activity before, during and after submaximal and maximal exercise in healthy young subjects. Plasma adrenaline, noradrenaline and dopamine increased to 8.5 (range 7.4–40.5), 48.0 (32.3–100.5) and 1.8 (1.2–6.6) nmol l–1 respectively (n = 5), during maximal exercise and decreased towards control values within 15 min of rest. Pancreatic polypeptide (n = 10) increased only during maximal exercise and reached its highest value, 48 (21–145) pmol l–1, after exertion. The results conform to an increase in sympathetic activity during exercise and a persistent vagal activity after intense exercise which could contribute to the sensation of weakness.  相似文献   
6.
Oppression of the chest, cough and orthopnea are well known to occur in some athletes after competitions, maybe reflecting an increase in lung water. In order to indicate if lung water increases after maximal exercise we measured pulmonary diffusion capacity before and 2.1 h after a short maximal arm exercise bout in 11 canoeists and showed a decrease of 6.7%. The result may be explained by a calculated 17% increase in alveolar interstitial volume.  相似文献   
7.
Sympathoadrenal and parasympathetic responses to exercise   总被引：1，自引：0，他引：1  
Exhaustive exercise is associated with a persistent sensation of weakness and sometimes nausea suggesting abdominal vagal activity. We measured plasma indices of sympathoadrenal (adrenaline, noradrenaline, dopamine) and vagal (pancreatic polypeptide) activity before, during and after submaximal and maximal exercise in healthy young subjects. Plasma adrenaline, noradrenaline and dopamine increased to 8.5 (range 7.4-40.5), 48.0 (32.3-100.5) and 1.8 (1.2-6.6) nmol 1-1 respectively (n = 5), during maximal exercise and decreased towards control values within 15 min of rest. Pancreatic polypeptide (n = 10) increased only during maximal exercise and reached its highest value, 48 (21-145) pmol 1-1, after exertion. The results conform to an increase in sympathetic activity during exercise and a persistent vagal activity after intense exercise which could contribute to the sensation of weakness.  相似文献   
8.
Oppression of the chest, cough and orthopnea are well known to occur in some athletes after competitions, maybe reflecting an increase in lung water. In order to indicate if lung water increases after maximal exercise we measured pulmonary diffusion capacity before and 2.1 h after a short maximal arm exercise bout in 11 canoeists and showed a decrease of 6.7%. The result may be explained by a calculated 17% increase in alveolar interstitial volume.  相似文献   
9.
The effect of inspiratory muscle training for 10 min twice a day for 27.5 days was evaluated in 20 human subjects, of whom 10 formed a training group and 10 a sham training group. The maximal oxygen uptake (VO2 max), maximal ventilation, breathing frequency during maximal exercise and the distance run in 12 min on a track were determined in addition to resting peak expiratory flow, forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1), with alveolar oxygen tension (pAO2) during maximal exercise being calculated. Inspiratory muscle training increased maximal inspiratory pressure from 93 (range 38-118) to 110 (65-165) mmHg in the training group (P less than 0.0005), but did not affect VO2 max, ventilation during maximal exercise, peak expiratory flow, FEV1 or FVC. However, breathing frequency during maximal exercise decreased slightly from 56 (44-87) to 53 (38-84) breaths min-1 (P less than 0.05) in the training group only; but the calculated pAO2 did not increase from the pre-training value of 126 (116-132) mmHg. The maximal distance run during 12 min increased similarly in the training and sham training groups by 8% (3-12%) and 6% (2-12%), respectively (P less than 0.01). The results of this study show that inspiratory muscle training resulting in a 32% (0-85%) increase in maximal inspiratory pressure does not change FEV1, FVC, peak expiratory flow, VO2 max or work capacity.  相似文献   
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