The test had a high reproducibility and sensitivity, allowing for detailed analysis of the physical capacity of athletes in intermittent sports. Specifically, the Yo-Yo intermittent recovery test was a valid measure of fitness performance in soccer. During the test, the aerobic loading approached maximal values, and the anaerobic energy system was highly taxed. Additionally, the study suggests that fatigue during intense intermittent short-term exercise was unrelated to muscle CP, lactate, pH, and glycogen.

We examined the hypothesis that O2 uptake (VO2) would change more rapidly at the onset of step work rate transitions in exercise with hyperoxic gas breathing and after prior high-intensity exercise. The kinetics of VO2 were determined from the mean response time (MRT; time to 63% of total change in VO2) and calculations of O2 deficit and slow component during normoxic and hyperoxic gas breathing in one group of seven subjects during exercise below and above ventilatory threshold (VT) and in another group of seven subjects during exercise above VT with and without prior high-intensity exercise. In exercise transitions below VT, hyperoxic gas breathing did not affect the kinetic response of VO2 at the onset or end of exercise. At work rates above VT, hyperoxic gas breathing accelerated both the on- and off-transient MRT, reduced the O2 deficit, and decreased the VO2 slow component from minute 3 to minute 6 of exercise, compared with normoxia. Prior exercise above VT accelerated the on-transient MRT and reduced the VO2 slow component from minute 3 to minute 6 of exercise in a second bout of exercise with both normoxic and hyperoxic gas breathing. However, the summated O2 deficit in the second normoxic and hyperoxic steps was not different from that of the first steps in the same gas condition. Faster on-transient responses in exercise above, but not below, VT with hyperoxia and, to a lesser degree, after prior high-intensity exercise above VT support the theory of an O2 transport limitation at the onset of exercise for workloads >VT.

Objective To assess the effect of a multifaceted intervention directed at general practitioners on six year mortality, morbidity, and risk factors of patients with newly diagnosed type 2 diabetes.Design Pragmatic, open, controlled trial with randomisation of practices to structured personal care or routine care; analysis after 6 years. Setting 311 Danish practices with 474 general practitioners (243 in intervention group and 231 in comparison group). Participants 874 (90.1%) of 970 patients aged >40 years who had diabetes diagnosed in 1989-91 and survived until six year follow up. Intervention Regular follow up and individualised goal setting supported by prompting of doctors, clinical guidelines, feedback, and continuing medical education. Main outcome measures Predefined clinical non-fatal outcomes, overall mortality, risk factors, and weight. Results Predefined non-fatal outcomes and mortality were the same in both groups. The following risk factor levels were lower for intervention patients than for comparison patients (median values): fasting plasma glucose concentration (7.9 v 8.7 mmol/l, P = 0.0007), glycated haemoglobin (8.5% v 9.0%, P < 0.0001; reference range 5.4-7.4%), systolic blood pressure (145 v 150 mm Hg, P = 0.0004), and cholesterol concentration (6.0 v 6

The purpose of this study was to investigate the hypothesis that cycling efficiency in vivo is related to mitochondrial efficiency measured in vitro and to investigate the effect of training status on these parameters. Nine endurance trained and nine untrained male subjects (V O 2 peak = 60.4 ± 1.4 and 37.0 ± 2.0 ml kg −1 min −1 , respectively) completed an incremental submaximal efficiency test for determination of cycling efficiency (gross efficiency, work efficiency (WE) and delta efficiency). Muscle biopsies were taken from m. vastus lateralis and analysed for mitochondrial respiration, mitochondrial efficiency (MEff; i.e. P/O ratio), UCP3 protein content and fibre type composition (% MHC I). MEff was determined in isolated mitochondria during maximal (state 3) and submaximal (constant rate of ADP infusion) rates of respiration with pyruvate. The rates of mitochondrial respiration and oxidative phosphorylation per muscle mass were about 40% higher in trained subjects but were not different when expressed per unit citrate synthase (CS) activity (a marker of mitochondrial density). Training status had no influence on WE (trained 28.0 ± 0.5, untrained 27.7 ± 0.8%, N.S.). Muscle UCP3 was 52% higher in untrained subjects, when expressed per muscle mass (P < 0.05 versus trained). WE was inversely correlated to UCP3 (r = −0.57, P < 0.05) and positively correlated to percentage MHC I (r = 0.58, P < 0.05). MEff was lower (P < 0.05) at submaximal respiration rates (2.39 ± 0.01 at 50%V O 2 max ) than at state 3 (2.48 ± 0.01) but was neither influenced by training status nor correlated to cycling efficiency. In conclusion cycling efficiency was not influenced by training status and not correlated to MEff, but was related to type I fibres and inversely related to UCP3. The inverse correlation between WE and UCP3 indicates that extrinsic factors may influence UCP3 activity and thus MEff in vivo.

Objective-To investigate the effects on general practitioners' activities of a change in their remuneration from a capitation based system to a mixed fee per item and capitation based system.Design-Follow up study with data collected from contact sheets completed by general practitioners in one period before (March 1987) a change in their remuneration system and two periods after (March 1988, November 1988, with a control group of general practitioners with a mixed fee per item and capitation based system throughout.Setting-General practices in Copenhagen city (index group) and Copenhagen county (control group).-Subjects-265 General practitioners in Copenhagen city, of whom 100 were selected randomly from the 130 who agreed to participate (10 exclusions) and 326 general practitioners in Copenhagen county.Main outcome measures-Number of consultations (face to face and by telephone) and renewals of prescriptions, diagnostic and curative services, and specialist and hospital referrals per 1000 enlisted patients in one week.Results-Of the 75 general practitioners who completed all three sheets, four were excluded for incomplete data. Total contact rates per 1000 patients listed rose significantly compared with the rates before the change index in the city (100-0 before the change v 111-7 (95% confidence interval 106-4 to 117-4 after the change) and over the same time in the control group (100.0 v 106-0), but within a year these rates fell (to 104-2 (991-to 109-6) and 104-0 respectively). There was an increase in consultations by telephone initially but not thereafter. Rates of examinations and treatments that attracted specific additional remuneration after the change rose significantly compared with those before (diagnostic services, 138-1 (118-7 to 160-5) and 159-5 (137-8 to 184-7) and curative services 194-6 (152-2 to 248.9) and 194-8 (152-3 to 249-2) for second and third data collections respectively) and with the control group (diagnostic services 105-3, 107*6 and curative services 106-0, 115-0) whereas referral rates to secondary care fell (specialist referrals 90-1 (80-7 to 100-6) and 77-0 (68-6 to 86.4) and hospital referrals 87-4 (71-1 to 107-5) and 68-4 (54.7 to 85.4)) in doctors in the city.Conclusions-Introducing a partial fee for service system seemed to stimulate the provision of services by general practitioners, resulting in reduced referral rates. The concept of a "target income" which doctors aim at, rather than maximising their income seemed to play a part in adjustment to changing the system of remuneration.

We investigated the hypothesis that the pulmonary oxygen uptake (V O 2 ) slow component is related to a progressive increase in muscle lactate concentration and that prior heavy exercise (PHE) with pronounced acidosis altersV O 2 kinetics and reduces work efficiency. Subjects (n = 9) cycled at 75% of the peakV O 2 (V O 2 peak ) for 10 min before (CON) and after (AC) PHE.V O 2 was measured continuously (breath-by-breath) and muscle biopsies were obtained prior to and after 3 and 10 min of exercise. Muscle lactate concentration was stable between 3 and 10 min of exercise but was 2-to 3-fold higher during AC (P < 0.05 versus CON). Acetylcarnitine (ACn) concentration was 6-fold higher prior to AC and remained higher during exercise. Phosphocreatine (PCr) concentration was similar prior to exercise but the decrease was 2-fold greater during AC than during CON. The time constant for the initialV O 2 kinetics (phase II) was similar but theV O 2 asymptote was 14% higher during AC. The slow increase inV O 2 between 3 and 10 min of exercise during CON (+7.9 ± 0.2%) was not correlated with muscle or blood lactate levels. PHE eliminated the slow increase inV O 2 and reduced gross exercise efficiency during AC. It is concluded that theV O 2 slow component cannot be explained by a progressive acidosis because both muscle and blood lactate levels remained stable during CON. We suggest that both theV O 2 slow component during CON and the reduced gross efficiency during AC are related to impaired contractility of the working fibres and the necessity to recruit additional motor units. Despite a pronounced stockpiling of ACn during AC, initialV O 2 kinetics were not affected by PHE and PCr concentration decreased to a lower plateau. The discrepancy with previous studies, where initial oxidative ATP generation appears to be limited by acetyl group availability, might relate to remaining fatiguing effects of PHE.

This study from Danish general practice gives figures about the simultaneous prevalence of asthma and allergic rhinitis and the order of onset among 7662 patients, who during 1 year consulted for one or both of these diseases. Twenty-eight percent of patients with asthma consulted because they also had allergic rhinitis, and 17% of patients with allergic rhinitis consulted because they also had asthma. Age- and sex-distributions are presented. In 25% of patients with both diseases the onset of both diseases occurred within the same year, while in 35% the onset of asthma occurred first and in 40% allergic rhinitis. Among patients with both diseases, who did not have onset of both within the same year, more than 75% of them had onset of one disease within 2 years of the other.

Recreational runners can improve RE and aerobic run performance by exchanging parts of their conventional aerobic distance training with intensive distance or long-interval running, whereas short-interval running is less efficient. The improvement in RE may relate to reduced ventilatory demands. Muscle fiber type distribution was unaltered with training and showed no associations with RE.