bluuebunny/crossref_metadata_2025 huggingface dataset:
The relationship of sustained exercise training and bone mineral density in aging male runners
Authors: Goodpaster B. H. , Costill D. L. , Trappe S. W. , Hughes G. M.
Published: July 2010

Fifty‐six men aged 42–73 years (50.2±10.0 years), who were competitive distance runners 20–25 years previously, were examined for bone mineral density (BMD) to determine the relationship between sustained distance running and BMD. Subjects were classified as being highly trained (HT, n=17), moderately trained (MT, n=29) or untrained (UT, n=10) according to their training in recent years. Subjects in each group were of similar age (HT 46.5±2.01, MT 53.0±1.51, UT 46.7±2.44 years) and lean body mass. Total body weight (kg) and percentage fat, however, were significantly greater (P<0.05) in the UT group than in either the MT or HT groups (UT 80.6±2.44 kg, 22.0±1.16%; MT 74.9±1.51 kg, 17.5±0.61%; HT 70.5±1.71 kg, 13.5±0.59%). Lumbar vertebrae and hip region BMD (g·cm−2) was determined via dual energy X‐ray absorptiometry (DEXA). No differences in BMD were found among the three groups in either the lumbar (HT 1.00±0.02, MT 1.02±0.03, UT 1.07±0.04 g·cm−2) or the hip regions (HT 0.99±0.03, MT 0.98±0.02, UT 1.06±0.04 g·cm−2). Furthermore, none of the groups had BMD that was significantly different from age‐matched normative values taken from a reference database. A moderate correlation was found between body weight and BMD when combining all subjects (r=0.38 for lumbar and r=0.41 for hip). These results indicate that middle‐aged to older males who have sustained exercise training in the form of running do not have significantly different lumbar vertebrae or hip region BMD compared to individuals who run less or not at all.
Ankle arthroscopy under local and general anaesthesia for diagnostic evaluation and treatment
Authors: Rolf C. , Saro C. , Engsträm B. , Wredmark T. , Movin T. , Karlsson J.
Published: July 2010

Improvements in techniques and instrumentation are extending the diagonstic and therapeutic indications for ankle arthroscopy. We aimed to stydy the diagnostic and therapeutic benefits and complication rate from 112 consecutive ankle arthroscopies performed between 1991 and 1994 under local and general anaestesia. One‐hundred and twelve outpatient ankle arthroscopies were performed in 72 male and 37 female patients, 16–64 years old. The patients were comparable in terms of gender and age in the arthroscopies done under local (n=69) and the arthroscopies done under general anaeshesia (n=43). The indications for surgery were pain in 75%, instability in 15%, limited function in 7% and swelling in 4%, and these criteria were similar in both groups. Anteromedial and anterolateral portals were used in all cases. No tourniquet was used and an external distractro was used in one case only. In 64 cases (57%) surgery was performed and included synovectomy, removal of loose bodies, shaving‐drilling of osteochondritic or other cartilage lesions, resection of impinging osteophytes, fibrosis and meniscoid lesions. In 95 ankles (85%) a definite diagnosis was established. Comparable diagnostic and therapeutic potentials were found between local and general anaesthesia. The complication rate was low. One patient who was operated on under general anaesthesia sustained a deep infection, and three suffered minor superficial nerve injuries. In concusion, ankle arthroscopy may be performed under local or general anaesthesia with similar diagonstic value and with a low complication rate.
Exercise intensity. An important factor in the etiology of menstrual dysfunction?
Authors: Tomten S. E. , Høstmark A. T. , Strømme S. B.
Published: July 2010

The objective of this case control study was to compare training activity in female long distance runners with irregular (IR, n=13) and regular (R, n=16) menstrual function, especially with regard to exercise intensity. Serum estradiol concentration during the follicular phase was considered normal in the R subjects (31±6 pg/1). In contrast, the IR runners were clearly hypoestrogenic (11±1.6 pg/1). The two groups had similar Vo2max' anaerobic threshold (AT) and maximal heart frequency (HFmax). In both groups AT was found at 88% of HFmax' The two groups had similar mean race results in half marathons during the previous year. The number of running contests was, however, twice as high in the IR group. A light portable pulse recorder was used to monitor heart rate during 1 week of regular training activity, and during a controlled high intensity work‐out. During a week with normal training activity, an equal amount of training at high intensity levels (>85% HFmax) was performed by the two groups. The amount of training at lower intensities (<85% HFmax) was, however, more extensive in the group with irregular menstrual function. During the controlled self‐administered, high intensity work‐out, the amounts of training at and above AT were equal in the two groups. In conclusion: no difference in extent of high intensity training between long distance runners with regular and irregular menstrual function could be found in the present study group. The IR runners did, however, have significantly more training activity at lower intensity levels, and more frequent race participation.
Physical activity pattern in men and women at the ages of 16 and 34 and development of physical activity from adolescence to adulthood
Authors: Barnekow‐Bergkvist M. , Hedberg G. , Janlert U. , Jansson E.
Published: July 2010

The aim of this study was to investigate gender‐related differences in physical activity patterns at the ages of 16 and 34 and to analyse those factors that might contribute to an explanation of physical activity habits in adulthood. A randomly selected group, consisting of 220 boys and 205 girls, was tested in 1974 and reinvestigated in 1992 by means of a questionnaire. Eighty‐eight percent participated in the reinvestigation. At the age of 16 more boys (69%) than girls (51%) participated in some sports activity in their leisure time. The results showed an overall decrease in participation in vigorous physical activity, although participation in light physical activity remained relatively constant. At the age of 34, there was no difference in overall physical activity between men and women, but the men exercised more vigorously (44% vs. 29%). Early experience of physical activity at the age of 16 decreased the risk of becoming inactive in adulthood. At the age of 34 cohabiting for the men, and having children and high socio‐economic class for the women, increased the risk of being physically inactive in adulthood, whereas positive beliefs about health effects of exercise decreased the risk for both men and women.
Stability of habitual physical activity and sport participation: a longitudinal tracking study
Authors: Telama R. , Leskinen E. , Yang X.
Published: July 2010

Although one of the most important aims of physical education and public sport policy is to encourage life‐long habitual physical activity, very little is known of the stability or tracking of physical activity. As a part of a larger research project called Cardiovascular Risks in Young Finns, the purpose of the study reported here was to investigate the stability (tracking) of leisuretime physical activity and sport participation at intervals of 3, 6, 9 and 12 years from age 9 to 30. The subjects, chosen by stratified random sample, represent five geographical areas of the country and eight gender‐age cohorts (9, 12, 15 and 18 years old in 1980). Physical activity and sport participation were measured using a short questionnaire. Tracking was analysed by Spearman's rank order correlations and by simplex model. The tracking correlations within a 3‐year interval of all individual variables were significant but rather low. The tracking correlations of the sum index of physical activity comprising five variables varied from 0.50 to 0.80 among boys and from 0.40 to 0.61 among girls. Simplex models that fitted the data very well showed higher stability coefficients than rank order correlations. With one exception the correlations of physical activity index within the 12‐year interval were significant but low.
Effects of meal frequency on body composition during weight control in boxers
Authors: Iwao S. , Mori K. , Sato Y.
Published: July 2010

The effects of meal frequency on changes in body composition by food restriction were investigated. Twelve boxers were divided between a two meals day−1 group (the 2M group) and a six meals day−1 group (the 6M group). Both groups ingested 5.02 MJ (1200 kcal) day−1 for 2 weeks. Although there was no difference in change of body weight by food restriction between the two groups, the decrease in lean body mass (LBM) was significantly greater in the 2M group than in the 6M group. The decrease in urinary 3‐methylhistidine/creatinine was significantly greater in the 6M group than in the 2M group. These results suggest that the lower frequency of meal intake leads to a greater myoprotein catabolism even if the same diet is consumed.
Omega‐3 fatty acid supplementation does not improve maximal aerobic power, anaerobic threshold and running performance in well‐trained soccer players
Authors: Raastad T. , Hastmark A. T. , Strømme S. B.
Published: July 2010

In a randomized, placebo‐controlled study the effect of 10 weeks of supplementation with either 5.2 g of a concentrated fish oil triglyceride (Triomar™) enriched in omega‐3 fatty acids (1.60 g/day EPA and 1.04 g/day DHA) or 5.2 g corn oil (serving as placebo) on maximal aerobic power, anaerobic threshold and running performance was assessed in 28 well‐trained male soccer players (18–35 years). Supplements were given as 650‐mg capsules. Capsule assignment was randomized to one omega‐3 group (n=15), given eight Triomar™ capsules per day, and one placebo group (n=13), given eight capsules of corn oil per day. During the 10‐week supplementation period the subjects maintained their usual diets and training regimes. Red blood cell (RBC) osmotic fragility, triglycerides and fatty acid composition in plasma were assessed before and after the supplementation period. The pre‐ and post‐supplementation tests of maximal aerobic power, anaerobic power and running performance showed no significant difference between the two groups. Subjects in the omega‐3 group had significantly reduced plasma triglycerides, rised EPA (175%) and DHA (40%) in the total lipid fraction of plasma after supplementation. RBC osmotic fragility did not change. In conclusion, the results do not support the hypothesis that endurance athletes can improve maximal aerobic performance by omega 3‐fatty acid supplementation.
A prospective study of injuries in licensed floorball players
Authors: Wikström J. , Andersson C.
Published: July 2010

Injuries occuring among 457 licensed floorball players in teh Swedish National League were analysed prospectively during the season from 1993 to 1994. Fifty‐one (11%) players sustained 58 injuries. The majority (76%) of the injuries were due to trauma mostly during the game (55%). Twenty‐three (52%) of the traumatic injuries were caused by an opponent or a stick. Ankle sprain (35%) was the most common diagnosis. Injury severity classified with regard to time of absence from sport participation were similarly distributed for minor (36%), moderate (29%) and major (35%) injuries. The total rate of injury was 2.5 per 1000 hours for female and 2.6 for male players. Although this rate is lower than for contact sports like soccer and ice‐hockey, we feel that further investigation of floorball injuries and improvement of protection devices would be valuable.
Effect of acute endurance and strength exercise on circulating calcium‐regulating hormones and bone markers in young healthy males
Authors: Rong H. , Berg U. , Tørring O. , Sundberg C. J. , Granberg B. , Bucht E.
Published: July 2010

Physical activity plays a role in the maintenance of the skeleton but the mechanical, metabolic and hormonal mechanisms involved are largely unknown. The influnence of acute endurance and strength exercise on circulating levels of calcitonin, parathyroid hormone (PTH), PTH‐related peptide (PTHrP), osteocalcin, carboxyterminal cross‐linked telopeptide of type I collagen (ICTP) and ionized calcium (Ca2+) was therefore evaluated. Eight healthy young males performed three exercise bouts on separate accasions: endurance exercise i.e. cycling on a cycle ergometer for 45 mim at 55% of Vo2max (E55%) and 15 min at 85% of Vo2max (E 85%) and strength exercise at 85% of three repetitions maximum using a legpress device (STR). Control experiments included the same subjects with the same time schedule but without exercise. Blood samples were taken before, immediately after exercise and during the recovery period. Hormones and bone markers were measured by use of various immunoassays. There was no obvious influence on calcitonin and PTHrP levels, whereas PTH was increased after strength exercise. ICTP and osteocalcin levels correlated positively at all times and showed regular variations. In comparison with the controls, ICTP levels showed a more pronounced decrease following physical activity whereas osteocalcin followed the same pattern as the controls except for after prolonged endurance exercise when a decrease was abolished. In conclusion, an increase in PTH after strength exercise and a pronounced decrease in ICTP after all exercise together with a relative increase in osteocalcin after prolonged endurance exercise might reflect some mechanisms involved in the positive effect of physical activity on bone mass.
The effect of inhaled salbutamol and salmeterol on lung fuction and endurance performance in healthy well‐trained athletes
Authors: Carlsen K.‐H. , Ingjer F. , Kirkegaard H. , Thyness B.
Published: July 2010

The present randomized, double‐blind placebo‐controlled study aimed at investigating the possible improvement in endurance performance caused by inhaled salmeterol (long‐acting β2‐agonist) and salbutamol (short‐acting) compared to placebo in 18 healthy well‐trained athletes, aged 17–30 years old. Lung function (flow‐volume loops) was measured before and after each inhaled study drug and after run to exhaustion. After inhalation of study drug and 10 min warm‐up, anaerobic threshold was measured; thereafter maximum oxygen uptake, peak ventilation and running time until exhaustion during a brief graded exercise were measured. No significant differences were found for ventilation, oxygen uptake or heart rate at anaerobic threshold or at maximum performance between placebo and the β2‐agonists. Lung function increased significantly after exercise, but without differences between the β2‐agonists and placebo. Running time till exhaustion was significantly reduced after both the long‐and the short‐acting β2‐agonist compared to the placebo.
Pregnancy in endurance athletes
Authors: Penttinen J. , Erkkola R.
Published: July 2010

The purpose of the present study was to examine pregnancy and delivery among Finnish endurance athletes at the national top level. A questionnaire concerning first. pregnancy was sent to 30 Finnish endurance athletes who had been at national top level in cross‐country skiing, running, speed‐skating or orienteering. Data on labour were collected retrospectively through a questionnaire and from the diaries in the hospital concerned. The next primipara in the diaries formed a member of the control group. Twenty‐three athletes (77%) had regular menstrual cycles, seven (23%) had irregularities, and four of them had received hormonal treatment for this. Seven athletes (23%) had experienced spontaneous abortion during the first trimester in previous pregnancy. Sixteen (53%) did not notice any change in their exercise performance, three (10%) subjectively felt themselves to be in a better physical condition, and seven (23%) felt themselves to be in a worse condition than before the pregnancy. Four did not respond on the question. After delivery, 18 athletes continued to compete, the median interval being 8.2 months (range 2–24 months). Two of them (11%) achieved a better condition than before the pregnancy, 11 (61%) reached the same level and five (28%) did not achieve the same performance level. There were no significant differences in labour parameters between the athletes and controls. Endurance training had no harmful side‐effects on the pregnancies or deliveries of the athletes. The effect of pregnancy on exercise performance is individual.
Bone scintigraphy in sports medicine: a review
Authors: Kanstrup I. L.
Published: July 2010

Bone scintigraphy is of growing interest to the sports physicians in the evaluation of benign disorders of the musculoskeletal system. It is atraumatic and easily applied, and being very sensitive a normal scintigram excludes pathophysiological conditions or mechanical disorders of the bones and joints. The indication is mainly suspicion of stress fractures, where a graduation is possible allowing prognostic interpretation. The finding of stress fractures in female athletes with long‐lasting amenorrhea may warrant further interest in the bone mineral content of the skeleton. In the diagnostic evaluation of particularly longer‐lasting joint‐related pain in younger subjects without obvious degenerative disease, bone scintigraphy is very sensitive to exclude joint affection, but not very specific to reveal an exact diagnosis. In athletes with back pain and radiographically demonstrated spondylolysis, tomography of bone scintigrams (SPECT) may discern between an actively healing process, probably eliciting the pain, and an inactive, healed proces not responsible for the back pain. Bone tumors always show increased uptake in bone scintigraphy, but the method does not allow a reliable differentiation between benign and malign etiology.
Competence, perceived importance of competence and drop‐out from soccer: a study of young players
Authors: Ommundsen Y. , Vaglum P.
Published: July 2010

The purpose of this study was to examine the psychological centrality hypothesis and the selectivity/discounting hypothesis advanced by Rosenberg and Harter and the motivational consequences thereof within the context of soccer. A representative sample of 223 young soccer players aged 12–16 who were interviewed twice within a period of 16 months served as subjects. Within the younger as well as the older group of players, the psychological centrality hypothesis received support in that the influence of perceived soccer competence upon soccer‐related self‐esteem was shown to be dependent upon the personal importance of one's own soccer competence. The psychological selectivity/discounting hypothesis, stating that players actively value or devalue how personally important they consider soccer competence to be as a result of changes in the perception of such competence, was also supported. Additional results showed that perceived importance of soccer competence did neither mediate nor moderate soccer drop‐out among players with low perceived soccer competence. Low perceived soccer competence, on the other hand, clearly mediated the relationship between low actual soccer competence and increased drop‐out within the group of older players.
Lactate production and clearance in exercise. Effects of training. A mini‐review
Authors: Stallknecht B. , Vissing J. , Galbo H.
Published: July 2010

Lactate accumulates if pyruvate formation exceeds pyruvate oxidation. Accelerated glycogenolysis is essential for lactate production. Glycogen and epinephrine enhance glycogen phosphorylase activity and this is higher in type II b than in type I fibers. Pyruvate oxidation is enhanced by exercise‐ induced increase in pyruvate dehydrogenase activity and is relatively impaired by low oxygen availability and low mitochondrial oxidative capacity. During exercise lactate is eliminated in liver, heart, and resting and working muscle. In muscle, elimination depends on plasma concentration, fiber type, and fiber conditions. Due to influence on hormonal response, mitochondrial oxidative capacity and fiber recruitment, training diminishes glycogenolysis and lactate production. Training also increases lactate clearance. This reflects increased hepatic capacity for gluconeogenesis as well as increased lactate transport capacity and oxidative capacity and reduced glycogenolysis in muscle. The fact that endurance performance can be predicted from the plasma lactate versus exercise intensity relationship illustrates that the plasma lactate level is a finely balanced result of the interplay between many factors of importance for endurance exercise.
Isokinetic muscle strength and hiking performance in elite sailors
Authors: Aagaard P. , Beyer N. , Simonsen E. B. , Larsson B. , Magnusson S. P. , Kjær M.
Published: July 2010

The aim of the present study was to describe the isokinetic strength profile and its relation to hiking performance in male (Sm, n=15) and fmale (Sf, n=6) elite sailors compared to a group of male control subjects (Cm, n=8) similar in age, anthropometry and level of fitness. Eccentric knee extension strength was higher in Sm compared to Cm. (P<0.01). Furthermore, Sm were stronger during trunk extension (P < 0.05), but not during trunk flexion compared to CM. Overall muscle strength was lower in SF compared to SM (P < 0.01) and CM (P < 0.05), except for eccentric knee extension strength, where SF and CM did not differ (P > 0.05). Hiking performance correlated to maximal eccentric and isometric knee extensor strength in SF (rs= 0.83–0.88, P < 0.05) and in CM (rs= 0.73‐0.77, P < 0.05) and to maximal eccentric knee extensor strength at high velocity in SM (rs= 0.46‐0.54, P < 0.05). For a subgroup of hikers in SM (n= 8), hiking peformance correlated to maximal isometric‐eccentric knee extensor strength (rs=0.67‐0.74, P<0.05), whereas no correlations emerged for the non‐hikers (n=7). Few correlations were observed between hiking performance and maximal concentric trunk flexor strength (rs=0.69‐0.92, P < 0.05). Unexpectedly, in SM correlations also were observed between hiking performance and maximal strength of the trunk extensors (rs=0.46‐0.53, hike subgroup: rs=0.64‐0.67, P < 0.05). In conclusion, notably high levels of maximal eccentric knee extesor strength were observed for the male and female elite sailors examined in the present study. Furthermore, the present results suggest that hiking performance depends in part on maximal isometric‐eccentric knee extensor strength. The maximal strength of the trunk extensors, which potentially stabilizes the lower back and spine, also seems to have some importance for the hiking performance of top‐level sailors.
A prospective cohort study of anterior cruciate ligament injuries in elite Norwegian team handball
Authors: Myklebust G. , Mæhlum S. , Holm I. , Bahr R.
Published: July 2010

The purpose of this study was to examine gender differences in the incidence of anterior cruciate ligament (ACL) injuries in a population of highlevel team handball players. We also wanted to examine injury mechanisms and possible risk factors for ACL injuries, including menstrual status. The study was done prospectively during the 1993‐94, 1994‐95, and 1995–96 seasons. We found 28 ACL injuries, 23 among women (incidence: 0.31 ± 0.06 injuries per 1000 player hours) and 5 among men (0.06 ± 0.03 inj./1000 h; P < 0.001 vs women; risk ratio: 5.0). Of the 28 injuries, 24 occurred during competiton (0.91 ± 0.19 inj./1000 h; women: 1.60 ± 0.35 inj./1000 h; men: 0.23 ± 0.13 inj./1000 h; P±0.001 vs. women; risk ratio: 7.0) and 4 during training (0.03 ± 0.02 inj./1000 h; P±0.001 vs. competition; risk ratio: 29.9). Nearly all the injuries (n= 25) occurred in noncontact situations when the players performed high‐speed plant‐and‐cut movements which they were well accustomed to. A reliable menstrual history could be obtained in 17 of the 23 cases among females. Five of the injuries occurred in the menstrual phase, 2 in the follicular phase, 1 in the early luteal phase and 9 in the late luteal phase (chi‐square3 d.f.= 13.2; P±0.01). The results suggest that there may be an increased risk of ACL injury during the week prior to or after the start of the menstrual period.
Stress, control, and coping in elite athletes
Authors: Pensgaard A. M. , Ursin H.
Published: July 2010

The main object of this study was to explore different dimensions of the stress experience and the following coping efforts among elite athletes. Sixty‐nine Norwegina Winte Olympic athletes, competing in the Lillehammer Games in 1994 participated in the study. Recall of the most stressfull experiences was reported through open‐ended questions following the Olympic Games, and the actual time of the experience with the following coping efforts were measured with the COPE inventory (19). The stress was mainly experienced during the time period prior to the competition. External distractions and expectations were the most frequently reported stress experiences. The coach was viewed as a major source of stress by some athletes, with a subsequent lack of control and low satisfaction with performance. Type of stress more than the time of the experience seemed to have a deterimental effect on performance. Problem‐focused coping strategies were employed at all times, while cognitive defense strategies were employed more days before (time phase 1) and after the competition (time phase 4).
Effects of walking training on health‐related fitness in healthy middle‐aged adults—a randomized controlled study
Authors: Kukkonen‐Harjula K. , Laukkanen R. , Vuori I. , Oja P. , Pasanen M. , Nenonen A. , Uusi‐Rasi K.
Published: July 2010

The effects of walking training on VO2max, serum lipoproteins and plasma fibrinogen were studied in 119 healthy middle‐aged persons. Training prescription was 65–75% of VO2max, 50 min/session, four times a week for 15 weeks. The net difference (between pre‐posttraining changes in the walking and control group) was statistically significant for VO2max (0.14 1 · min−1, 95% CI 0.04, 0.23), total cholesterol (−0.20 mmol · 1−1, CI −0.34, −0.06), LDL cholesterol (−0.17 mmol · 1−1, CI −0.29, −0.05), ratio of HDL cholesterol to total cholesterol (0.014, CI 0.005, 0.023), and triglycerides (−0.15 mmol · 1−1, CI −0.26, −0.04). No statistically significant changes occurred in fibrinogen. The findings indicate that walking training of moderate intensity resulted in a modest increase in VO2max and minor but consistently favorable changes in serum lipoproteins.
Early arthroscopic treatment of primary traumatic anterior shoulder dislocation. A follow‐up study
Authors: Valentin A. , Winge S. , Engstrom B.
Published: July 2010

This study evaluates the results of early arthroscopic Bankart repair in patients with primary traumatic anterior dislocation of the shoulder. The patients’age range was 17–34 years. Arthroscopic Bankart repair was performed within 12 days after the dislocation. First follow‐up was at 18 months. According to Rowe's score, 11 patients (73%) were excellent, 3 (20%) were good and 1 (7%) was poor. The median external rotation deficit was 4 in the adducted position. At a second follow‐up at 34 months, two patients had redislocated. Both of these patients had severe generalized joint laxity. Another patient reported frequent subluxations. We conclude that in young patients with primary anterior traumatic shoulder dislocation, early arthroscopic Bankart repair implies a low recurrence rate and restores shoulder function to normal. Generalized joint laxity could indicate an increased risk for recurrent dislocation.
Exercise and organ transplantation
Authors: Kjær M. , Beyer N. , Secher N. H.
Published: July 2010

Life‐saving treatment of disease by organ transplantation has become increasingly important. Annually over 35 000 transplantations of vital organs are carried out world‐wide and the demand for knowledge regarding exercise in daily life for transplant recipients is growing. The present review describes whole‐body and organ reactions to both acute exercise and regular physical training in persons who have undergone heart, lung, liver, kidney, pancreas or bone marrow transplantation. In response to acute exercise, the majority of cardiovascular, hormonal and metabolic changes are maintained after transplantation. However, in heart transplant recipients organ denervation reduces the speed of heart rate increase in response to exercise. Furthermore, lack of sympathetic nerves to transplanted organs impairs the normal insulin and renin responses to exercise in pancreas and kidney transplant recipients, respectively. In contrast, surgical removal of sympathetic liver nerves does not inhibit hepatic glucose production during exercise, and denervation of the lungs does not impair the ability to increase ventilation during physical exertion. Most studies show that physical training results in an improved endurance and strength capacity in almost all groups of transplant recipients, which is of importance for their daily life. With a little precaution, organ transplant recipients can perform exercise and physical training and obtain effects comparable with those achieved in the healthy population of similar age.
Motor performance in different dynamic tests in knee rehabilitation
Authors: Pfeifer K. , Banzer W.
Published: July 2010

Functional dynamic tests are increasingly used in rehabilitation after injuries of the lower extremities. In these tests quantitative measures (e.g. time, height, distance) are mainly used as parameters, whereas the quality of the neuromuscular performance is poorly evaluated. In the present study the neuromuscular performance of leg muscles in different motor tasks was investigated 10–16 months after ACL‐reconstruction. In 39 subjects with arthroscopically assisted ACL‐reconstruction and 20 controls, isometric knee extensor strength, thigh circumference, knee stability, subjective knee function and the neuromuscular performance (by kinematic data and EMG) during three dynamic tests (stair descending, one‐legged drop jump, one‐legged cyclic hops) were measured. During the strength measurements a superimposed twitch technique was used for the detection of neuromuscular inhibition. The results demonstrate a significantly reduced Lysholm‐Score and a distinct strength deficit, but no neuromuscular inhibition and no differences in knee stability in the operated leg. Besides reduced motor abilities of the injured leg, significant differences of the neuromuscular performance could be detected. It was evident that different test conditions revealed different persisting changes of the neuromuscular performance, which could not be detected by kinematic parameters alone.
The effect of supervised rehabilitation on strength, postural sway, position sense and re‐injury risk after acute ankle ligament sprain
Authors: Holme E. , Magnusson S. P. , Becher K. , Bieler T. , Aagaard P. , Kjær M.
Published: July 2010

The effect of an early rehabilitation program, including postural training, on ankle joint function after an ankle ligament sprain was investigated prospectively. Ninety‐two subjects, matched for age, sex, and level of sports activity, were randomized to a control or training group. All subject received the same standard information regarding early ankle mobilization. In addition, the training group participated in supervised physical therapy rehabilitation (1 h. twice weekly) with emphasis on balance training. Postural sway, position sense and isometric ankle strength were measured 6 weeks and 4 months after the injury, and at 12 months re‐injury data were obtained. In the training group, there was a significant difference between the injured and uninjured side for plantar flexion (P<0.01), eversion (P<0.01) and inversion (P<0.05), but not for dorsiflexion at 6 weeks. In the control group, there was a significant difference between the injured and uninjured side for plantar flexion (P<0.01), eversion (P<0.01), inversion (P<0.01), and dorsiflexion (P<0.05) at 6 weeks. Postural sway, but not position sense, differed between the injured and uninjured side in both groups (P<0.01) at 6 weeks. The side‐to‐side percent differences were similar in both groups for all variables (P>0.05) at 6 weeks, and there were no side‐to‐side differences at 4 months in either group. In the control group, 11/38 (29%) suffered a re‐injury. while this number was only 2/29 (7%)) in the training group (P<0.05). These data showed that an ankle injury resulted in reduced ankle strength and postural control at 6 weeks, but that these variables had normalized at 4 months, independent of the supervised rehabilitation. However, the findings also demonstrated that supervised rehabilitation may reduce the number of re‐injuries, and therefore may play a role in injury prevention.
EMG activity of the iliopsoas muscle and leg kinetics during the soccer place kick
Authors: Dörge H. C. , Andersen T. Bull , Sørensen H. , Simonsen E. B. , Aagaard H. , Dyhre‐Poulsen P. , Klausen K.
Published: July 2010

The purpose of the study was to develop a method to record intramuscular electromyogram (EMG) from the iliopsoas muscle and to relate this activity to the kinetics during the soccer place kick. Seven skilled soccer players performed 3 maximal velocity place kicks. The kicks were filmed with a high‐speed camera (400 Hz) and EMG recordings were obtained from 5 muscles of the kicking leg, including wire electrodes inserted into the m. iliopsoas. The EMG signals were compared to the kinetics of the kicking leg, which were calculated from the digitised film. The results showed hardly any torque reversal about the hip joint before impact. Angular deceleration of the thigh segment did not increase the angular velocity of the shank (work ‐3.57 to 0.0%). M. iliopsoas was active during the entire kicking motion (average EMG 65.1–100.9%), even in the period when the thigh was decelerating. Wire electrodes can succesfully be applied to EMG recordings of fast unloaded movements.
Choice of jumping strategy in two standard jumps, squat and countermovement jump‐effect of training background or inherited preference?
Authors: Ravn S. , Voigt M. , Simonsen E. B. , Alkjær T. , Bojsen‐Møller F. , Klausen K.
Published: July 2010

Six male subjects, three professional ballet dancers and three elite volleyball players, performed maximal vertical jumps from 1) a static preparatory position (squat jump), 2) starting with a countermovement (counter‐movement jump) and 3) a specific jump for ballet and for volleyball, respectively. The jumps were recorded on highspeed film (500 Hz) combined with registration of ground reaction forces, and net joint moments were calculated by inverse dynamics. The purpose was to investigate the choice of strategy in two standard jumps, squat jump and countermovement jump. The volleyball jump was performed with a sequential strategy and the ballet jump was performed with a simultaneous strategy. In the two standard jumps, the choice of strategy was individual and not related to training background. This was additionally confirmed in a test of seven ballet dancers and seven volleyball players.
Influence of exercise and menstrual cycle phase on plasma homocysteine levels in young women ‐ a prospective study*
Authors: De Crée C. , Malinow M. R. , van Kranenburg G. P. , Geurten P. G. , Longford N. T. , Keizer H. A.
Published: July 2010

Plasma total homocysteine (tHcy) has been identified as an independent risk factor for cardiovascular diseases (CVD). The difference in tHcy between the sexes has most often been related to the sex hormones, but also to a higher muscle mass in men. The purpose of this study was to assess the effects of acute exercise, brief exhaustive training, and menstrual cycle phase on circulating plasma tHcy concentrations. Fifteen untrained eumenorrheic women (mean age [±SD]: 18.7±0.4 yr. body fat: 25.8±3.4%, VO2max: 43.8±2.3 ml · kg−1· min−1) volunteered for the present study, which covered two menstrual cycles. During the second cycle the subjects participated in two exhaustive 5‐day training programs on a cycle erg‐ometer: one in the follicular (FPh) and one in the luteal phase (LPh). Pre‐and posttraining plasma tHcy and total estrogen (E) responses were determined in blood samples obtained immediately before, during and immediately after incremental exercise to exhaustion. tHcy levels showed a large between‐subject variation, but differences between FPh and LPh levels were consistent (P=0.063). Mean tHcy levels at rest were 9.44±1.65 μmol/L and 8.93±1.71 μmol/L during the FPh and LPh. respectively. Brief exhaustive training did not elicit any changes in plasma tHcy concentrations. although posttraining LPh E levels were lower (P<0.01). Overall, the differences between FPh and LPh values for tHcy and E were attenuated by training. Acute exercise increased plasma tHcy concentrations (P<0.001). At exhaustion. tHcy levels increased by 17% and 16% during the FPh and LPh. respectively. This was also significantly above tHcy levels at submaximal exercise (P=0.044). After a short period of training tHcy levels did not increase as much during acute exercise as they did before training; however, the increments were still significant (P=0.048). In conclusion, acute exercise in women produces significant increases in plasma tHcy concentrations, whereas brief exhaustive training does not significantly alter plasma tHcy levels. Our findings also suggest that plasma tHcy concentrations are menstrual cycle phase‐dependent and that there is a close association between estrogen status and tHcy levels.
Long‐term outcome of knee and ankle injuries in elite football
Authors: Larsen E. , Jensen P. K. , Jensen P. R.
Published: July 2010

To estimate the risk and evaluate the long‐term outcome of knee and ankle injuries in former national team elite football, 69 players were randomly selected, followed by clinical and stress radiographic examinations. Thirthy‐nine players (49 knees) had had knee injuries and 29 ankle injuries (35 ankles). The median time from injury until study examination was 25 years. The knee injuries were tears of the medial collateral ligament (MCL) in 24 cases combined with rupture of the anterior cruciate ligament (ACL) and meniscus lesions in three. Meniscus lesions had occurred in 17 cases including three combined with ACL and MCL and another two with ACL ruptures. Isolated rupture of the ACL had occurred in four cases. The ankle lesions were in 26 of 35 cases ruptures of the lateral ligaments. In all, 12 players had completely stopped football and three had changed occupation. Signs of arthritis were present in 63% of the injured knees and in 33% of the injured ankles. The incidence of arthritis in the group of 17 uninjured players was 26% in the knee and 18% the ankle. In elite football players knee and ankle injuries seem to have a serious long‐term outcome, but also uninjured players have a higher risk of developing arthritis than the normal population.
Early mobilization versus immobilization after ankle ligament stabilization
Authors: Karlsson J. , Lundin O. , Lind K. , Styf J.
Published: July 2010

Functional outcome, stability at radiographic investigation and ankle joint torque after anatomical reconstruction of the lateral ankle ligaments were evaluated in patients with early postoperative mobilization versus those with cast immobilization. Thirty patients with chronic lateral ligament instability of the ankle underwent anatomical reconstruction of the ligaments. Postoperatively the patients were randomly allocated to two groups: Group A (n= 15) were immobilized in a below‐knee plaster for 6 weeks and Group B (n= 15) underwent early controlled range of motion training using an Air‐Cast® ankle brace. The funtional results were evaluated using a scoring scale and objective results using standardized stress radiographs. Also eccentric and concentric muscle torque at 60°/s was measured in plantar flexion and dorsiflexion, respectively. The functional results were satisfactory in 12/15 ankles in Group A and 14/15 in Group B (n.s.). All the patients with satisfactory results regained normal range of motion. Patients with unsatisfactory results had either residual pain or recurrent instability. In Group B, the strength measurements revealed significantly higher peak torque values after three months in plantar flexion at 60°/s. Six months postoperatively, the torque values did not differ significantly between the groups. Also, there was no group difference in the laxity of the ankle joint, including both anterior talar translation test and talar tilt test, at the two‐year follow‐up. One patient had a superficial wound infection. We conclude that after the reconstruction of chronic lateral ligament instability of the ankle the functional and stability results were equally good with early postoperative mobilization and 6‐week immobilization. However, using early mobilization plantar flexion strength was regained earlier than with cast immonbilization, without any risk of short‐ or medium‐term complications, such as increased ankle laxity. We recommend early mobilization after anatomical reconstruction of the lateral ankle ligaments.
Resistance training in the oldest old: consequences for muscle strength, fiber types, fiber size, and MHC isoforms
Authors: Kryger A. I. , Andersen J. L.
Published: July 2010

Resistance training‐related changes in muscle strength, muscle size, fiber type, and myosin heavy chain isoform composition in 11 elderly subjects (age range, 85–97 years) after 12 weeks of heavy resistance training (80% of 1 RM) were examined. Twelve subjects constituted a control group. Resistance training increased isometric knee extensor strength 37% (P<0.05) and isokinetic knee strength 41–47% (P<0.05). Lean‐quadriceps cross‐sectional area increased 9.8% (P<0.05). Muscle fiber hypertrophy occurred only in the type 2 fibers (22% (P<0.05)). Type 1 fiber‐type area percentage decreased [4.0 % (P<0.05)] whereas fiber‐type area percentage of type 2a fibers increased [5.9% (P<0.05)]. The relative amount of myosin heavy chain (MHC) I (P<0.05) decreased and the relative amount of MHC IIA increased (P<0.05). No effects in the overall number of capillaries per area was observed, but an increase in the number of capillary contacts in the type 2 fiber pool was observed. Heavy resistance training does have beneficial effects on muscle strength and muscle volume in very old frail humans. Furthermore, an increase in fiber size of the fast muscle fibers and an overall increase in the relative amount of fast MHC IIA can lead not only to a stronger, but maybe more importantly, to a more powerful skeletal muscle.
Are the prevalence and treatment of asthma similar in elite athletes and the aged‐matched non‐athlete population?
Authors: Locke S. , Marks G.
Published: July 2010

The objective of this study was to determine the prevalence of asthma and use of asthma medications in elite athletes compared with an age‐matched non‐athlete population. Data were collected from the respiratory component of annual medical screening of 424 elite athletes from the Queensland Academy of Sport. Measures included the prevalence of current asthma and ever doctor‐diagnosed asthma, and the prevalence of use of treatment for asthma including β‐agonists and inhaled corticosteroid medication. The prevalence of current asthma in athletes aged 18–29 years was 14% (95% CI, 9–19%), which did not differ significantly from the prevalence in the non‐athlete control population (11%; 95% CI, 9–12%, P=0.3). Of athletes with current asthma, 27% were not taking any medications for asthma, and 25% were treated with short‐acting β‐agonist medications alone and were not taking inhaled corticosteroids. These data indicate that the overall cumulative and period prevalence of asthma in Queensland athletes is similar to that in the general age‐matched population. Athletes use β‐agonists with a frequency similar to the general population.
Ankle function during hopping in subjects with functional instability of the ankle joint
Authors: Delahunt E. , Monaghan K. , Caulfield B.
Published: July 2010

A common mechanism of inversion injury involves a lateral movement producing a hypersupination of the ankle joint. To date, no study has investigated patterns of muscle activity, three‐dimensional (3D) joint kinematics and kinetics simultaneously in a group of subjects with functional instability (FI) compared with a non‐injured control group during a lateral hopping test. Twenty‐six subjects with the subjective complaint of FI of the ankle joint and 24 non‐injured healthy control subjects volunteered to participate in the study. We measured 3D lower limb kinematics, kinetics and surface electromyography (EMG) of the rectus femoris, tibialis anterior, peroneus longus and soleus muscle in all subjects during a lateral hop task for the period 200 ms pre‐ and post‐initial contact (IC). FI subjects were observed to have a less‐everted position of the ankle joint during the time period from 45 ms pre‐IC to 95 ms post‐IC (P<0.05). FI subjects were also found to have an increase in pre‐ and post‐IC rectus femoris, tibialis anterior and solues EMG activity. The results suggest that subjects with FI exhibit changes in ankle joint movement and neuromuscular control that could predispose to further injury.
Relationship between quadriceps femoris muscle volume and muscle torque after anterior cruciate ligament repair
Authors: Konishi Y. , Ikeda K. , Nishino A. , Sunaga M. , Aihara Y. , Fukubayashi T.
Published: July 2010

This study was performed to obtain evidence regarding bilateral hindrance of motor unit (MU) recruitment in the quadriceps femoris (QF) of patients with anterior cruciate ligament (ACL) reconstruction. The subjects included 70 patients who underwent ACL reconstruction and 35 healthy subjects. To identify the muscle torque per unit volume (MTPUV), the peak torque of each velocity of isokinetic performance was divided by muscle volume of the QF measured by a series of cross‐sectional images obtained by magnetic resonance imaging scans. Tests revealed that the mean MTPUV of the uninjured (0.113±0.03 N m/cm3 at 60°/s, 0.081±0.02 N m/cm3 at 180°/s) and injured sides (0.109±0.03 N m/cm3 at 60°/s, 0.079±0.023 N m/cm3 at 180°/s) were significantly lower than those of the control group (0.144±0.05 N m/cm3 at 60°/s, 0.096±0.04 N m/cm3 at 180°/s). Previous studies suggested that MU recruitment in the QF of patients with ACL injury was hindered bilaterally. However, the design of their studies could not provide evidence of bilateral hindrance of MU recruitment in the QF. The results of the present study demonstrated that the MTPUV of both injured and uninjured sides of patients were significantly lower than those of the control group.
Effect of exercise‐induced muscle damage on endurance running performance in humans
Authors: Marcora S. M. , Bosio A.
Published: July 2010

Exercise‐induced muscle damage (EIMD) is known to decrease muscle strength and power but its effect on endurance performance is unclear. Thirty moderately trained adult runners (24 men and six women) were randomly assigned to EIMD or control. The EIMD group jumped 100 times from a 35 cm bench, while controls did not perform any muscle‐damaging exercise. Before and 48 h after treatment, subjects were tested on markers of EIMD, steady‐state cardiorespiratory, metabolic and perceptual responses during a constant speed submaximal run; distance ran in 30 min on a treadmill. There were significant changes in muscle soreness, creatine kinase, and knee extensors strength (P<0.01). This EIMD significantly reduced self‐paced time trial performance by 4% (P<0.01) because subjects reduced running speed (P=0.02), with no change in perceived exertion (P=0.31). No significant alterations in running economy and other physiological responses to submaximal running were found. However, there was a trend (P=0.08) for increased perceived exertion, which was correlated with decreased time trial performance (P<0.01). In conclusion, EIMD has a significant impact on endurance running performance in humans, and this effect seems to be mediated by alterations in the sense of effort.