[Putative effects of doping in cycling]

After recent scandals in cycling involving doping, it has been asserted that top-level cycling is impossible without pharmacological support. An important prerequisite for successfully completing the Tour de France is maintaining energy balance. To compensate for the daily caloric expenditure of 23-25 MJ, conventional food must be supplemented with liquid food. Quick administration of liquid carbohydrates is essential for optimal recovery of glycogen stores in the liver and skeletal muscle. Androgenic anabolic steroids are a frequently used form of doping. In endurance sports, these drugs have not been shown to affect endurance performance, and there is little evidence to suggest that they enhance recovery. Although epoetin use can increase maximal oxygen uptake, its effects on maximal power output are less pronounced than what is generally assumed. A relationship between haemoglobin concentration and sport performance has not been proved. It has been found that growth hormone rather has a negative than a positive influence on the sport performance. The doping problem is due in part to superstition, hearsay and insufficient knowledge among the athlete's support personnel, which frequently leads to medical malpractice in sport. Education and quality control for sport professionals, including sports physicians, may help to control the doping problem.

Is minimally invasive surgery less invasive in total hip replacement? A pilot study

It has been suggested that minimally invasive surgery (MIS) in total hip replacement (THR) is less traumatic than standard techniques. This study was designed to address the question of whether an anterior MIS approach generates less inflammation and muscle damage than the standard posterolateral (PL) approach. Inflammation parameters such as interleukin-6 (IL-6), muscle damage parameters like heart type fatty acid binding protein (H-FABP), and haemoglobin (Hb) levels were determined pre-operatively and at five consecutive points post-operatively in 10 patients operated through a MIS anterior approach and in 10 patients operated through a PL approach. The mean IL-6 concentration increased from 3 pg/ml in both groups pre-operatively to 78.5 pg/ml (PL group) vs 74.8 pg/ml (MIS group) at 6 hours post-operatively and reached a maximum of 100 pg/ml (PL group) vs 90.5 pg/ml pg/ml (MIS group) after 24 hours. Up to this time point, there was a decrease in both groups. The post-operative mean H-FABP concentration increased to 10.7 microg/l in the PL group vs 15.8 microg/l in the MIS group. It formed a plateau and decreased after 24 hours post-operatively. The Hb levels were 14.5 g/dl before surgery and decreased to 10.7 g/dl (PL group) and 10.0 g/dl (MIS group) at 72 hours post-operatively. No significant differences were found between the two approaches either in inflammation and muscle damage or blood loss. Although the absence of a learning curve may explain the lack of a difference between both techniques, we speculate that the term MIS is at least doubtful in terms of being less traumatic.

Experience in the first four years of rapid recovery; is it safe?

The average length of hospital stay after Total Hip Replacement (THR) has been decreasing over time. Recently, many hospitals have commenced rapid recovery programs such as Joint Care. In Joint Care the patients are usually discharged on the fifth post-operative day with relatively fresh surgical wounds. The aim of this study is to evaluate the Joint Care program after THR. Between February 2000 and February 2004, the Joint Care program was used in 611 patients after THR. The average age of the patients was 66.3 yrs (SD 9.3; range 24-86 yrs) and 68% (n= 415) of them were female. All clinical and outpatient charts as well as nursery records were evaluated. The follow up was from 6 months to 4 years (average: 2.5 years). At the planned fifth post-operative day, 92% (n = 562) of patients were discharged from hospital (SD 1.7 days; range 6-25 days). 3.8% (n= 23) of the remaining cases faced wound problems--prolonged wound drainage in 2.3% (n = 14) and potential superficial infection in 1.5% (n = 9) - causing a delay in their discharge. The readmission rate was 6.4% (n = 39) due to hip dislocation (3.4%; n = 21), re-evaluation of wound (1.5%; n= 9), deep infection (1.2%; n = 7)) and cardiac events (0.3%; n = 2). All the infection cases were treated effectively with debridement and antibiotics and no revision for any reason was reported. The Joint Care program seems to be effective after THR. Post-operative hip dislocation was the main reason for post-operative readmission. However, no clear signs that the intensive rehabilitation program caused more complications compared to previous regimens were evident. The above results encourage the application of rapid recovery programs in Orthopaedic surgery and joint replacement.

Injuries in synchronized skating

Synchronized skating is a relatively new competitive sport and data about injuries in this discipline are lacking. Therefore the purpose of this study was to investigate the frequency and pattern of acute and overuse injuries in synchronized skaters. Before and during the World Synchronized Skating Championship 2004, a questionnaire inquiring about the frequency of injuries in this skating discipline was given to 23 participating teams. A total of 514 women and 14 men senior skaters completed the questionnaires (100 % response). Two hundred and eighteen (42.4 %) female and 6 (42.9 %) male skaters had suffered from acute injuries during their synchronized skating career. As some skaters had suffered from more than one injury, the total number of acute injuries in females was 398 and in males 14. In female skaters 19.8 % of acute injuries were head injuries, 7.1 % trunk, 33.2 % upper, and 39.9 % lower extremity injuries. In male skaters 14.3 % were head injuries, 28.6 % upper, and 57.1 % lower extremity injuries, with no report of trunk injuries. Sixty-nine female and 2 male skaters had low back problems and 112 female and 2 male skaters had one or more overuse syndromes during their skating career. Of 155 overuse injuries in female skaters, 102 (65.8 %) occurred during their figure skating career, while 53 injuries (34.2 %) only occurred when they skated in synchronized skating teams. In male skaters, out of 5 overuse injuries, 4 (80 %) occurred in their figure skating career, while 1 (20 %) occurred during their synchronized skating career. Out of the total of 412 injuries, 338 (82 %) occurred during on-ice practice, while 74 (18 %) happened during off-ice training. Ninety-one (26.9 %) acute injures occurred while practicing individual elements, and 247 (73.1 %) on-ice injuries occurred while practicing different team elements. We conclude that injuries in synchronized skating should be of medical concern due to an increasing number of acute injuries, especially those that go beyond the soft tissue and include head injuries and fractures. We feel that these more significant injuries MAY TO SOME EXTENT BE attributable to the increasing physical demands and technical difficulty required of the teams now participating in a more competitive environment over the last four years.

Comparison of hematologic data in world elite junior speed skaters and in non-athletic juniors

During the world junior speed skating championship 2002 all athletes (60 males, 56 females) were subjected to hematologic blood testing one day before the competition as requested by International Skating Union--ISU. This study aimed to obtain hematological reference values for junior athletes, whilst the influence of endurance training on hematologic variables of young athletes was studied. Hematologic results of athletes were compared to results of non-athletes matched by age and gender (14 males, 17 females). The blood analysis was done on an ADVIA 120. To compare measurement of ferritin, erythropoietin, and soluble transferrin receptor in serum as well as in EDTA-plasma, serum and EDTA-blood was obtained from the control group. In hemoglobin and hematocrit we found no significant difference between the two groups, whereas the number of erythrocytes was lower in athletes. The mean corpuscular volume was higher in athletes, whilst the corpuscular hemoglobin content was only marginally higher in athletes than in non-athletes. Consequently corpuscular hemoglobin concentration mean was lower in athletes than in non-athletes. There was no difference of erythropoietin and soluble transferrin receptor, whilst in ferritin we found a difference between the groups. Endurance training does not change the values of hemoglobin and hematocrit. Increased mean corpuscular volume and decreased corpuscular hemoglobin concentration mean could be a result of changed properties of red blood cell-membrane caused by acidosis and higher osmolality during the training. In junior athletes we did not find an iron overload as described in some adult athletes.

The effects of creatine supplementation on selected factors of tennis specific training

BACKGROUND

Creatine supplementation is popular among tennis players but it is not clear whether it actually enhances tennis performance.

OBJECTIVES

To examine the effects of creatine supplementation on tennis specific performance indices.

METHODS

In a randomised, double blind design, 36 competitive male tennis players (24 creatine, mean (SD) age, 22.5 (4.9) years; 12 placebo, 22.8 (4.8) years) were tested at baseline, after six days of creatine loading, and after a maintenance phase of four weeks (14 creatine, 10 placebo). Serving velocity (10 serves), forehand and backhand velocity (three series of 5x8 strokes), arm and leg strength (bench press and leg press), and intermittent running speed (three series of five 20 metre sprints) were measured.

RESULTS

Compared with placebo, neither six days nor five weeks of creatine supplementation had a significant effect on serving velocity (creatine: +2 km/h; placebo: +2 km/h, p = 0.90); forehand velocity (creatine: +4 km/h; placebo: +4 km/h, p = 0.80), or backhand velocity (creatine: +3 km/h; placebo: +1 km/h, p = 0.38). There was also no significant effect of creatine supplementation on repetitive sprint power after 5, 10, and 20 metres, (creatine 20 m: -0.03 m/s; placebo 20 m: +0.01 m/s, p = 0.18), or in the strength of the upper and lower extremities.

CONCLUSIONS

Creatine supplementation is not effective in improving selected factors of tennis specific performance and should not be recommended to tennis players.

Hemoglobin and hematocrit values after saline infusion and tourniquet

This study attempted to contribute to standardization of blood testing in sport, and to investigate the effect of artificial dilution with saline. In 10 healthy, physically active males and 3 healthy physically active females hemoglobin (Hb), hematocrit (Ht), and % reticulocytes (%retics) were measured at different time points to look for possible fluctuations during day time, while the subjects had regular coffee breaks and lunch. In 7 of the subjects in a separate experiment 500 ml of saline were infused around 8 am and Hb, Ht, and %retics were measured before and every hour thereafter until 7 hours after infusion. In addition Ht was measured on a hematological analyzer as well as with a centrifuge. In a separate experiment the effect of tourniquet duration on Hb and Ht was studied in 9 of the subjects. The results show that Hb, Ht, and %retics are stable from 8 am to 4 pm, but that infusion of 500 ml of saline induces an acute decrease in Hb and Ht within one hour (Hb decreased from 15.2+/-0.9 g/dl to 14.5+/-1.0 g/dl, and Ht from 45.6+/-2.8 % to 44.0+/-2.5 %). The decline in Hb and Ht was maintained during the 7-hour observation period. Ht values of the same samples measured with a hematological analyzer and a centrifuge were not different. Application of the tourniquet did significantly affect Hb and Ht values only from two minutes, and thereafter Hb and Ht remained stable during the rest of the 5-minute tourniquet. With blood testing in sport these results have to be taken into consideration.

Accidental breaches of the doping regulations in sport: is there a need to improve the education of sportspeople?

OBJECTIVES

To identify educational needs of elite sportspeople with respect to the doping laws.

METHODS

A questionnaire survey of 196 Olympic level sportspeople from the fields of athletics, cycling, rowing, and sailing. The questionnaire addressed the date and source of the last doping educational update, the usefulness of current resources, sources of help, and possible ways of improving the system. The questionnaire also sought to estimate the use of nutritional supplements in these sports.

RESULTS

Seventy four (38%) athletes responded to the questionnaire. Over 90% of responders had received a doping educational update in the last six months, and most agreed with the statement "I have received the information I need to avoid getting into trouble with the doping laws". Despite this, more than half of responders agreed with the statements "I should receive reminders more often" and "The authorities should do more to educate sportspeople". In addition, there were four people who admitted taking a banned substance by accident. Forty one (55%) reported taking supplements. The team doctor was the most popular source if information on a substance or product was required, with 62% and 66% of subjects stating that they would contact their team doctor when based in the United Kingdom and abroad respectively. The UK Sports website was often suggested in relation to ways of improving knowledge.

CONCLUSIONS

There is a need to alter the educational process, particularly with respect to contingency planning for minor illness. The use of internet based resources for up to date information about banned substances needs to be promoted, and access to the internet improved. The educational needs of team doctors with respect to the doping laws need to be assessed.

Physiological, biochemical and psychological markers of strenuous training-induced fatigue

The purpose of the study was to investigate whether severe fatigue, possibly leading to overreaching, could be diagnosed at an early stage by a combination of parameters. Seven well-trained male subjects (age [mean +/- SD]: 25.3 +/- 4.7 yr; body mass: 76 +/- 6.6 kg; VO2max: 61.1 +/- 7 ml.kg(-1).min(-1)) increased their training load by doubling their training volume and increasing the intensity by 15 % over a period of two weeks. Before and after this intensified training period subjects underwent a series of tests including a maximal incremental cycle ergometer test (Wmax) with continuous ventilatory measurements and blood lactate values, time trial, basal blood parameter tests (red and white blood profile), hormones [growth hormone (GH), insulin-like growth factor 1(IGF-1), adreno-corticotropic hormone (ACTH), cortisol], neuro-endocrine stress test [short insulin tolerance test (SITT), combined anterior pituitary test (CAPT) and exercise], a shortened Profile of Mood State (POMS), the estimated rate of perceived exertion (RPE) and a cognitive reaction time test. The intensified training period resulted in a significant increase of the training load (p <0.01), training monotony (p <0.01) and training strain (p <0.01). The RPE during training increased significantly (p <0.01) during the intensified training period. Total mood score obtained from the POMS tended to increase (p=0.06), reflecting an increase in worse mood state. A novel finding was that reaction times increased significantly, indicating that overreaching might adversely affect speed of information processing by the brain, especially for the most difficult conditions. After the intensified training period, neither changes in exercise-induced plasma hormone values, nor SITT values were observed. During the CAPT only cortisol showed a significant decrease after the intensified training period. Hemoglobin showed a significant decrease after the intensified training period whereas hematocrit, red blood cell count (RBC) and MCV tended to decrease. The intensified training had no effect on physical performance (Wmax or time trial), maximal blood lactate, maximal heart rate and white blood cell profile. The most sensitive parameters for detecting overreaching are reaction time performance (indicative for cognitive brain functioning), RPE and to a lesser extend the shortened POMS. This strongly suggests, that central fatigue precedes peripheral fatigue. All other systems,including the neuro-endocrine, are more robust and react most likely at a later stage in exhaustive training periods.

Effects of androgenic-anabolic steroids on apolipoproteins and lipoprotein (a)

OBJECTIVES

To investigate the effects of two different regimens of androgenic-anabolic steroid (AAS) administration on serum lipid and lipoproteins, and recovery of these variables after drug cessation, as indicators of the risk for cardiovascular disease in healthy male strength athletes.

METHODS

In a non-blinded study (study 1) serum lipoproteins and lipids were assessed in 19 subjects who self administered AASs for eight or 14 weeks, and in 16 non-using volunteers. In a randomised double blind, placebo controlled design, the effects of intramuscular administration of nandrolone decanoate (200 mg/week) for eight weeks on the same variables in 16 bodybuilders were studied (study 2). Fasting serum concentrations of total cholesterol, triglycerides, HDL-cholesterol (HDL-C), HDL2-cholesterol (HDL2-C), HDL3-cholesterol (HDL3-C), apolipoprotein A1 (Apo-A1), apolipoprotein B (Apo-B), and lipoprotein (a) (Lp(a)) were determined.

RESULTS

In study 1 AAS administration led to decreases in serum concentrations of HDL-C (from 1.08 (0.30) to 0.43 (0.22) mmol/l), HDL2-C (from 0.21 (0.18) to 0.05 (0.03) mmol/l), HDL3-C (from 0.87 (0.24) to 0.40 (0.20) mmol/l, and Apo-A1 (from 1.41 (0.27) to 0.71 (0.34) g/l), whereas Apo-B increased from 0.96 (0.13) to 1.32 (0.28) g/l. Serum Lp(a) declined from 189 (315) to 32 (63) U/l. Total cholesterol and triglycerides did not change significantly. Alterations after eight and 14 weeks of AAS administration were comparable. No changes occurred in the controls. Six weeks after AAS cessation, serum HDL-C, HDL2-C, Apo-A1, Apo-B, and Lp(a) had still not returned to baseline concentrations. Administration of AAS for 14 weeks was associated with slower recovery to pretreatment concentrations than administration for eight weeks. In study 2, nandrolone decanoate did not influence serum triglycerides, total cholesterol, HDL-C, HDL2-C, HDL3-C, Apo-A1, and Apo-B concentrations after four and eight weeks of intervention, nor six weeks after withdrawal. However, Lp(a) concentrations decreased significantly from 103 (68) to 65 (44) U/l in the nandrolone decanoate group, and in the placebo group a smaller reduction from 245 (245) to 201 (194) U/l was observed. Six weeks after the intervention period, Lp(a) concentrations had returned to baseline values in both groups.

CONCLUSIONS

Self administration of several AASs simultaneously for eight or 14 weeks produces comparable profound unfavourable effects on lipids and lipoproteins, leading to an increased atherogenic lipid profile, despite a beneficial effect on Lp(a) concentration. The changes persist after AAS withdrawal, and normalisation depends on the duration of the drug abuse. Eight weeks of administration of nandrolone decanoate does not affect lipid and lipoprotein concentrations, although it may selectively reduce Lp(a) concentrations. The effect of this on atherogenesis remains to be established.

Skeletal Muscle wasting and contractile performance in septic rats

We investigated the temporal effects of sepsis on muscle wasting and function in order to study the contribution of wasting to the decline in muscle function; we also studied the fiber-type specificity of this muscle wasting. Sepsis was induced by injecting rats intraperitoneally with a zymosan suspension. At 2 h and at 2, 6, and 11 days after injection, muscle function was measured using in situ electrical stimulation, Zymosan injection induced severe muscle wasting compared to pair-fed and ad libitum fed controls. At 6 days, isometric force-generating capacity was drastically reduced in zymosan-treated rats. We conclude that this was fully accounted fo by the reduction of muscle mas. At day 6, we also observed increased activity of the 20S proteasome in gastrocnemius but not soleus muscle from septic rats. In tibialis anterior but not in soleus, muscle wasting occurred in a fiber-type specific fashion, i.e., the reduction in cross-sectional area was significantly smaller in type 1 than type 2A and 2B/X fibers. These findings suggest that both the inherent function of a muscle and the muscle fiber-type distribution affect the responsiveness to catabolic signals.

The effect of different nutritional feeds on the postprandial glucose response in healthy volunteers and patients with type II diabetes

OBJECTIVE

Assessment of postprandial glycaemic response to four nutritional feeds with different macronutrient and fibre composition.

DESIGN

A randomized, double-blind, crossover study.

SETTING

University of Maastricht, the Netherlands.

SUBJECTS

A total of 10 healthy volunteers and 10 patients with type II diabetes.

INTERVENTIONS

Subjects received 200 kcal of four enteral nutrition products (two standard products and two diabetes-specific products). Fasting and postprandial plasma glucose were measured for 2 h. Peak glucose level and area under the curve were calculated.

RESULTS

In healthy volunteers and diabetic patients, the feed with a low carbohydrate (CHO), high monounsaturated fatty acid (MUFA) and high fibre content significantly decreased peak glucose concentration and area under the curve compared to the feeds with standard composition.

CONCLUSIONS

Special feeds with a low CHO, high MUFA and high fibre content improve glycaemic balance and therefore should be considered in diabetic patients who are in need of nutritional support.

Inhaled salbutamol and endurance cycling performance in non-asthmatic athletes

Beta(2)-adrenergic agonists are important therapeutic agents for the prevention and treatment of (exercise-induced) asthma in athletes, but may have ergogenic effects. In this study we investigated whether inhalation of a supra-therapeutic dose of 800 microg salbutamol before exercise affects endurance performance during a cycling trial in non-asthmatic athletes. In a double-blind, randomized cross-over study, 16 athletes performed two trials, where they had to perform a certain amount of work as fast as possible on a cycle ergometer, 30 minutes after inhalation of 800 micro g salbutamol or placebo. Peak expiratory flow (PEF), forced vital capacity (FVC), and forced expiratory volume in 1 second (FEV(1)) were measured before and after exercise and blood samples were obtained before and during exercise. Cycling performance time was 4010.2 +/- 327.7 s after placebo inhalation and 3927.6 +/- 231.3 s after inhalation salbutamol (p < 0.05). Although salbutamol inhalation increased plasma free fatty acids, glycerol and lactate concentrations and decreased plasma potassium concentrations at rest, no differences between placebo and salbutamol in these variables were found during exercise. PEF and FEV(1) were increased after salbutamol inhalation at rest compared with placebo, but the difference between placebo and salbutamol after exercise was no longer significant. Inhalation of a supratherapeutic dose of 800 micro g salbutamol improved endurance cycling performance by 1.9 +/- 1.8 % in non-asthmatic athletes, which indicates that this route of administration does not exclude the possibility of an ergogenic effect of beta(2)-adrenergic agents in athletes. The increase in performance was not explained by changes in plasma concentrations of free fatty acids, glycerol, lactate, and potassium during exercise or by changes in ventilatory parameters at rest and after exercise. Therefore, the mechanism of the increase in performance remains to be determined.

Physical activity as measured by accelerometry in children receiving growth hormone

AIM

Parents of children treated with growth hormone (GH) frequently report to the paediatrician that their children have become more physically active. In the present study, activity patterns of GH-treated children were measured and compared to those of healthy controls.

METHODS

Subjects were 25 children at the start of GH treatment (age 8.4 +/- 2.6 y) and 19 age- and gender-matched controls (age 8.8 +/- 3.2 y). Physical activity was assessed with a tri-axial accelerometer for movement registration over two separate 2-wk intervals, one before the start of GH treatment and one 2 wk after the start of treatment. GH-treated subjects were categorized as poor responders (change in height over 1 y <0.7 SDS, n = 15) or good responders (change in height over 1 y >0.7 SDS, n = 10).

RESULTS

Before therapy, good responders showed a significantly lower physical activity compared to healthy controls, spending significantly less time on high-intensity activities. This difference disappeared 2 wk after the start of therapy. Physical activity in poor responders was not significantly different from controls before and after 2 wk of GH therapy.

CONCLUSION

Children who respond well to GH therapy (change in height >0.7 SDS) showed a reduced amount of physical activity before therapy, which was normalized after 2 wk of GH therapy.

Physical activity pattern of children assessed by triaxial accelerometry

OBJECTIVES

Accelerometry was used to assess the relationship between the physical activity level (PAL) and time spent on activities of various intensities in children.

DESIGN

A total of 20 children aged 8.6+/-3.3 y wore a triaxial accelerometer (Tracmor2) for 2 weeks. PAL was calculated with Tracmor2 output data. The fraction of time spent on activities with a given level of intensity (low, moderate, high) was calculated. The fractions of time spent on activities of different intensities were compared with previously obtained data for young adults and elderly persons.

RESULTS

PAL showed an inverse relation with the percentage of time spent on low-intensity activities (r = -0.76; P < 0.0001) and a positive relation with the percentage of time spent on high-intensity activities (r = 0.93; P < 0.0001). The fraction of time spent on low-intensity activities was smaller in children than in young adults (P < 0.05) and elderly persons (P < 0.0001), while the fraction spent on high-intensity activities (P < 0.0001) was larger.

CONCLUSIONS

The present data are important for a better understanding of physical activity in children, which is necessary for education and prevention about physical (in)activity in childhood. Our observations suggest that to obtain a higher PAL in children, they should be given the opportunities to perform high-intensity activities.

Effects of stage duration in incremental running tests on physiological variables

To study the effect of stage duration on some physiological variables in an incremental running test, 8 well-trained runners underwent 3 running tests, with stage durations of 1, 3 and 6 min. To study maximal lactate steady state (maxLASS) and its corresponding speed, every subject underwent a 4th test with three 15-min stages at three speeds, based on the running speed at 4 mmol/l blood lactate (V4) in the 6 min per stage protocol. The first load in the 15 min per stage test was V4 - 0.5 km/h, the second at V4, and the third V4 + 0.5 km/h. To compare the maxLASS speed with outdoor performance, the subjects also ran 5 km at this speed on an outdoor track. Mean maximal running speed (V (max)) in the incremental test was significantly lower in the 6-min (15.1 km/h) and 3-min stage protocol (17.1 km/h), compared with the 1-min stage protocol (18.3 km/h). Mean peak VO (2) and mean peak heart rate were not different between the protocols with different stage duration. The mean V4 was significantly lower in the 6 min per stage protocol compared with the 3 min per stage protocol (12.9 vs. 14.4 km/h). Mean ventilatory threshold was not different between the 1, 3 and 6 min per stage protocols. No threshold behaviour was found in respiratory rate. MaxLASS can be estimated from V4 in the 6 min per stage protocol, and verified by three 15-min intensities being V4 - 0.5 km/h, at V4, and V4 + 0.5 km/h. The mean blood lactate concentration at the maxLASS speed was not different between treadmill running and outdoor running on a track. In conclusion, for measuring peak values of physiological variables in an incremental running test, the duration per stage is of less importance, however, when measuring blood lactate concentration as a function of running speed, the duration per stage should be at least 6 min.

Effect of testosterone and endurance training on glycogen metabolism in skeletal muscle of chronic hyperglycaemic female rats

OBJECTIVES

To investigate in glycolytic and oxidative muscles of trained (nine weeks) and untrained hyperglycaemic female rats the effect of hyperandrogenicity and/or endurance training on energy metabolic properties.

METHODS

Glycogen content and activity of muscle enzymes with regulatory functions in glycogen synthesis were examined.

RESULTS

Testosterone treatment increased glycogen content of extensor digitorum longus (EDL) and soleus muscles of hyperglycaemic sedentary (18% and 84% respectively) and hyperglycaemic trained (7% and 16% respectively) rats. In both types of muscle of the hyperglycaemic testosterone treated exercised subgroup, less depletion of glycogen was found than in the untreated group (38% and 87% for EDL and soleus respectively).

CONCLUSIONS

The mechanisms by which training and/or hyperandrogenism alone or in combination elicits their specific effects are complex. Differences in sex, surgery, levels of hormones administered, and exercise model used may be the main reasons for the observed discrepancies. Conclusions from the results: (a) hyperandrogenism is not a primary cause of the development of insulin resistance; (b) glycogen content of slow and fast twitch muscle is increased by training through increased glycogen synthase activity. The most plausible explanation for differences between different muscle fibre types is the different levels of expression of androgen receptors in these fibres. Hyperandrogenicity therefore acts on energy metabolic variables of hyperglycaemic animals by different mechanisms in glycolytic and oxidative muscle fibres.

Prospective echocardiographic assessment of androgenic-anabolic steroids effects on cardiac structure and function in strength athletes

Since the abuse of androgenic-anabolic steroids (AAS) has been associated with the occurrence of serious cardiovascular disease in young athletes, we performed two studies to investigate the effects of short-term AAS administration on heart structure and function in experienced male strength athletes, with special reference to dose and duration of drug abuse. In Study 1 the effects of AAS were assessed in 17 experienced male strength athletes (age 31 +/- 7 y) who self-administered AAS for 8 or 12 - 16 weeks and in 15 non-using strength athletes (age 33 +/- 5 y) in a non-blinded design. In Study 2 the effects of administration of nandrolone decanoate (200 mg/wk i. m.) for eight weeks were investigated in 16 bodybuilders in a randomised double blind, placebo controlled design. In all subjects M-mode and two-dimensional Doppler-echocardiography were performed at baseline and after 8 weeks AAS administration. In the athletes of Study 1 who used AAS for 12 - 16 weeks a third echocardiogram was also made at the end of the AAS administration period. Echocardiographic examinations included the determination of the aortic diameter (AD), left atrium diameter (LA), left ventricular end diastolic diameter (LVEDD), interventricular septum thickness (IVS), posterior wall end diastolic wall thickness (PWEDWT), left ventricular mass (LVM), left ventricular mass index (LVMI), ejection fraction (EF) and right ventricular diameter (RVD). For assessment of the diastolic function measurements of E and A peak velocities and calculation of E/A ratio were used. In addition, acceleration and deceleration times of the E-top (ATM and DT, respectively) were determined. For evaluation of factors associated with stroke volume the aorta peak flow (AV) and left ventricular ejection times (LVET) were determined. In Study 1 eight weeks AAS self-administration did not result in changes of blood pressure or cardiac size and function. Additionally, duration of AAS self-administration did not have any impact on these parameters. Study 2 revealed that eight weeks administration of nandrolone decanoate did not induce significant alterations in blood pressure and heart morphology and function. Short-term administration of AAS for periods up to 16 weeks did not lead to detectable echocardiographic alterations of heart morphology and systolic and diastolic function in experienced strength athletes. The administration regimen used nor the length of AAS abuse did influence the results. Moreover, it is concluded that echocardiographic evaluation may provide incomplete assessment of the actual cardiac condition in AAS users since it is not sensitive enough to detect alterations at the cellular level. Nevertheless, from the present study no conclusions can be drawn of the cardiotoxic effects of long term AAS abuse.

Androgenic anabolic steroid use and severe hypothalamic-pituitary dysfunction: a case study

The data of the present case demonstrate that the abuse of androgenic anabolic steroids (AAS) may lead to serious health effects. Although most clinical attention is usually directed towards peripheral side effects, the most serious central side effect, hypothalamic-pituitary-dysfunction, is often overlooked in severe cases. Although this latter central side-effect usually recovers spontaneously when AAS intake is discontinued, the present case shows that spontaneous recovery does not always take place. We suggest that hypothalamic-pituitary dysfunction should always be considered in the differential diagnosis in athletes seen with typical presentation of anabolic steroid use. In order to regain normal hypothalamic-pituitary function, supraphysiological doses of 200 microg LH-RH should be considered when the physiological challenge test with LH-RH (50 microg) fails to show an acceptable response.

Rapid visuomotor preparation in the human brain: a functional MRI study

An important feature of human motor behaviour is anticipation and preparation. We report a functional magnetic resonance imaging study of the neuronal activation patterns in the human brain that are associated with the rapid visuomotor preparation of discrete finger responses. Our imaging results reveal a large-scale distributed network of neural areas involved in fast visuomotor preparation, including specific areas in the frontal cortex (middle frontal gyrus, premotor and supplementary motor cortex), the parietal cortex (intra-parietal sulcus, inferior and superior parietal lobe) and the basal ganglia. Our reaction time results demonstrate that it is easier to prepare two fingers on one hand than on two hands. This hand-advantage phenomenon was associated with relatively enhanced levels of activity in the basal ganglia and relatively reduced levels of activity in the parietal cortex. These findings provide direct evidence for differential activity in a distributed brain system associated with specific neuro-computational operations subserving fast visuomotor preparation.

The effects of acute exercise and high lactate levels on 35% CO2 challenge in healthy volunteers

OBJECTIVE

To test the possible antipanic effects of acute exercise in healthy volunteers exposed to an inhalation of 35% CO2 challenge.

METHOD

Twenty healthy subjects in a randomized separate group design, performed exercise in a bicycle ergometer reaching >6 mm of blood lactate and a control condition of minimal activity in the same fashion with no lactate elevation. Immediately afterwards an inhalation of a vital capacity using a mixture of 35% CO2/65% O2 through a mask was given on both conditions.

RESULTS

Subjects under the exercise condition reported less panic symptoms than controls after a CO2 challenge on the diagnostic statistical manual-IV (DSM-IV) Panic Symptom List but no difference on the Visual Analogue Anxiety Scale.

CONCLUSION

Subjects under the exertion condition had lactate levels comparable with those of lactate infusions but an inhibitory rather than accumulative effect was seen when combined with a CO2 challenge.

Red blood cell profile of elite olympic distance triathletes. A three-year follow-up

The purpose of this study was to monitor general and individual changes in hematological variables during long-term endurance training, detraining and altitude training in elite Olympic distance triathletes. Over a period of three years, a total of 102 blood samples were collected in eleven (7-male and 4 female) elite Olympic distance triathletes (mean +/- SD; age = 26.4 +/- 5.1 yr; VO(2) max = 67.9 +/- 6.6 ml/min/kg) for determination of hemoglobin (Hb), hematocrit (Hct), red blood cell count (RBC), Mean corpuscular hemoglobin (MCH), Mean corpuscular hemoglobin content (MCHC), Mean corpuscular volume (MCV) and plasma ferritin. The data were pooled and divided into three periods; off-season, training season and race season. Blood samples obtained before and after altitude training were analyzed separately. Of all measured variables only RBC showed a significant decrease (p < 0.05) during the race season compared to the training season. Hematological values below the lower limit of the normal range were found in 46 % of the athletes during the off-season. This percentage increased from 55 % during the training season to 72 % of the athletes during the race season. Hemoglobin and ferritin values were most frequently below the normal range. There was a weak correlation between Hb levels and VO(2) max obtained during maximal cycling (r = 0.084) and running (r = 0.137) tests. Unlike training at 1500 m and 1850 m, training at an altitude of 2600 m for three weeks showed significant increases in Hb (+ 10 %; p < 0.05), Hct (+ 11 %; p < 0.05) and MCV (+ 5 %; p < 0.05). Long-term endurance training does not largely alter hematological status. However, regular screening of hematological variables is desirable as many athletes have values near or below the lower limit of the normal range. The data obtained from altitude training suggest that a minimum altitude (>2000 m) is necessary to alter hematological status.