Effect of long haul travel on maximal sprint performance and diurnal variations in elite skeleton athletes

Objective

To quantify the impact of eastward long haul travel on diurnal variations in cortisol, psychological sensations and daily measurements of physical performance.

Methods

Five elite Australian skeleton athletes undertook a long haul eastward flight from Australia to Canada (LH_travel), while seven elite Canadian skeleton athletes did not travel (NO_travel). Salivary cortisol was measured on awakening, 60 min and 120 min after awakening. Psychological sensations were measured with a questionnaire, and maximal 30 m sprints were performed once a day between 09:30 and 11:00 h local time.

Results

Compared with baseline, average (SD) resting salivary cortisol decreased by 67% immediately after long haul travel (23.43 (5.71) nMol/l) (mean±90% confidence interval) in the LH_travel group (p = 0.03), while no changes were found in the NO_travel group (p = 0.74). There were no significant differences in 30 m sprint time between baseline and post‐flight tests in the LH_travel group (p>0.05). The LH_travel group perceived themselves as “jet lagged” for up to 2 days after the flight (p = 0.01 for both midday lunch and evening dinner).

Conclusions

Despite a distinct phase change in salivary cortisol rhythmicity and the athletes perceiving themselves as “jet lagged”, minimal disturbances in “one‐off” maximal sprinting ability between 09:30 and 11:00 h local time were seen in a group of elite skeleton athletes after long haul eastward travel from Australia to Canada.     

Screening elite winter athletes for exercise induced asthma: a comparison of three challenge methods

Background

The reported prevalence of exercise induced asthma (EIA) in elite winter athletes ranges from 9% to 50%. Many elite winter athletes do not report symptoms of EIA. At present there is no gold standard test for EIA.

Objective

To establish the efficacy of screening for EIA and examine the role of the eucapnic voluntary hyperventilation (EVH) challenge and laboratory based and sport specific exercise challenges in the evaluation of elite winter athletes.

Methods

14 athletes (mean (SD) age 22.6 (5.7) years, height 177.2 (7.0) cm, body mass 68.9 (16.9) kg) from the Great Britain short‐track speed skating (n = 10) and biathlon teams (n = 4) were studied. Each athlete completed a laboratory based and sport specific exercise challenge as well as an EVH challenge, in randomised order.

Results

All 14 athletes completed each challenge. Two had a previous history of asthma. Ten (including the two with a previous history) had a positive test to at least one of the challenges. Ten athletes had a positive response to EVH; of these, only three also had a positive response to the sport specific challenge. No athletes had a positive response to the laboratory based challenge.

Conclusions

Elite athletes should be screened for EIA. EVH is a more sensitive challenge in asymptomatic athletes than sport specific and laboratory based challenges. If sporting governing bodies were to implement screening programmes to test athletes for EIA, EVH is the challenge of choice.     

Injuries among elite snowboarders (FIS Snowboard World Cup)

Background

Although snowboarding is already established as an Olympic sport, it is still a developing sport, with new disciplines, more demanding snow installations, and spectacular tricks. A recent study on subjects at Norwegian national elite level showed that injury risk is high and that injuries among competitive snowboarders differ from those seen in recreational snowboarders, with fewer wrist injuries and more knee and back injuries.

Objective

To describe the incidence and type of injuries among female and male snowboarders at international elite level.

Method

At the last race of the Fédération Internationale de Ski Snowboard World Cup, acute injuries resulting in missed participation and overuse injuries influencing performance, were recorded during a retrospective interview (91% response rate). The registration period was from April 2002 (end of season) until March 2003. Exposure was recorded as the number of runs in all disciplines, and the incidence was calculated as number of injuries per 1000 runs.

Results

The 258 athletes interviewed reported 3193 competition days (n = 46 879 runs) in all disciplines. In total, 135 acute injuries were recorded; 62 (46%) during competition in the official disciplines. Of the 135 acute injuries, the most common injury locations were knee (n = 24; 18%), shoulder (n = 18; 13%), back (n = 17; 13%), and wrist (n = 11; 8%). The overall incidence during competition was 1.3 (95% confidence interval 1.0 to 1.7) injuries per 1000 runs; 2.3 (0.9 to 3.8) for big air (n = 10), 1.9 (1.1 to 2.8) for halfpipe (n = 21), 2.1 (1.2 to 3.0) for snowboard cross (n = 20), 0.6 (0.2 to 1.0) for parallel giant slalom (n = 8), and 0.3 (0.0 to 0.7) for parallel slalom (n = 3). The severity of injuries was graded based on time loss (27% lost >21 days) and score on the Abbreviated Injury Scale (AIS) (38% AIS 1, 61% AIS 2 and 1% AIS 3). There were 122 overuse injuries, 38 (31%) of these to the knee.

Conclusion

The injury risk for big air, snowboard cross, and halfpipe disciplines is high, while that for the snowboard slalom disciplines is lower. The injury pattern is different from recreational athletes, with a greater share of knee injuries and fewer wrist injuries. Compared with national level, the injury risk appears to be lower at World Cup level.     

A pilot study on the effects of pre-event manipulation on jump height and running velocity

Purpose

To compare changes in jump height and running velocity with and without pre‐event high‐velocity, low‐amplitude manipulation (HVLA).

Methods

A crossover study design with elite healthy athletes was used. After a 15 min warm‐up, the subjects were tested for countermovement jump height (CMJ) and flying 40 m sprint time (SPRINT). A sport chiropractor then evaluated each subject. Subjects were randomised to either HVLA (applied to joints based on examination) or placebo (simulated performance‐enhancement stickers). They then rested for 60 min, performed another 15 min warm‐up, and were retested. The protocol was repeated 48 h later with the alternative intervention. The mean of two sprints and three jumps were analysed, as well as peak performances. The sample size was based on prior results from the effects of stretching.

Results

19 subjects involved in sprint sports were enrolled; two were too sore to participate on day 2, and one could only participate in the jump (all had HVLA on day 1). Of the 17 participants analysed, seven were female, age range was 19–35, and 17 were national or world‐class athletes. The ranges for baseline measures were: SPRINT 4.1–5.5 s; CMJ 47.4–92.7 cm. Overall, the greater than expected variability in this pilot study led to the study being underpowered. Subjects tended to perform better after HVLA for both CMJ and SPRINT (both mean and peak results), but none of the results were statistically significant (p  =  0.30–0.61).

Conclusion

Although the larger than expected variability in the pilot study means that the observed clinically relevant differences were not statistically significant, the direction and magnitude of the changes associated with HVLA suggest that it may be beneficial. That said, the increased soreness after HVLA suggests that it may be detrimental. HVLA warrants further study.     

Sodium supplementation is not required to maintain serum sodium concentrations during an Ironman triathlon

Context

Critical assessment of recommendations that athletes consume additional sodium during athletic events.

Objective

To evaluate if sodium supplementation is necessary to maintain serum sodium concentrations during prolonged endurance activity and prevent the development of hyponatraemia.

Design

Prospective randomised trial of athletes receiving sodium (620 mg table salt), placebo (596 mg starch), or no supplementation during a triathlon. The sodium and placebo tablets were taken ad libitum, with the suggested range of 1–4 per hour.

Setting

The 2001 Cape Town Ironman triathlon (3.8 km swim, 180 km cycle, 42.2 km run).

Subjects

A total of 413 triathletes completing the Ironman race.

Main outcome measures

Sodium supplementation was not necessary to maintain serum sodium concentrations in athletes completing an Ironman triathlon nor required to prevent hyponatraemia from occurring in athletes who did not ingest supplemental sodium during the race.

Results

Subjects in the sodium supplementation group ingested an additional 3.6 (2.0) g (156 (88) mmol) sodium during the race (all values are mean (SD)). There were no significant differences between the sodium, placebo, and no supplementation groups with regard to age, finishing time, serum sodium concentration before and after the race, weight before the race, weight change during the race, and rectal temperature, systolic and diastolic blood pressure after the race. The sodium supplementation group consumed 14.7 (8.3) tablets, and the placebo group took 15.8 (10.1) tablets (p  =  0.55; NS).

Conclusions

Ad libitum sodium supplementation was not necessary to preserve serum sodium concentrations in athletes competing for about 12 hours in an Ironman triathlon. The Institute of Medicine''s recommended daily adequate intake of sodium (1.5 g/65 mmol) seems sufficient for a healthy person without further need to supplement during athletic activity.     

Risk factors for injuries in elite female soccer players

Objective

To describe risk factors for injuries in elite female soccer.

Methods

A total of 143 female soccer players from the German national league participated in the study. Baseline information on player characteristics—for example, anthropometric measurements and playing position—and medical history were recorded at the start of the study. During one outdoor season, injuries and training and match exposure times were prospectively documented for each player.

Results

The risk of a new anterior cruciate ligament (ACL) rupture was significantly increased in players with a previous rupture (odds ratio (OR)  =  5.24, p  =  0.01). This was not the case for ankle sprain (OR  =  1.39) or knee sprain (OR  =  1.50). In addition, no significantly increased risk of new sprains or ACL ruptures was found when the injured leg was the unit of analysis. Injury incidence was considerably higher in defenders (9.4 injuries per 1000 hours exposure) and strikers (8.4/1000 hours) than goalkeepers (4.8/1000 hours) and midfielders (4.6/1000 hours). Ten per cent of all players (n  =  14) sustained more than three injuries. Most of these were defenders (n  =  8) or strikers (n  =  4). Significantly more injuries occurred to the dominant leg (105 v 71, p  =  0.01); this was particularly true for contact injuries (52 v 29, p  =  0.01).

Conclusions

Injury risk should be assessed on an individual basis. Therefore it seems appropriate to individualise preventive training programmes, as is recommended for other training content. Evaluating the existing rules of soccer and their appropriate application may also help to decrease injury risk, particularly in contact situations.     

Concussive head injury in children and adolescents related to sports and other leisure physical activities

Objective

To compare the characteristics of children and adolescents with concussive head injury (CHI) sustained during organised sports or other leisure physical activity.

Methods

This was a case series study reviewing the medical records retrospectively over a four year period of children 6–16 years presenting to the emergency department with a CHI after participating in sport and/or recreation activity.

Results

There were 592 cases of sport and recreation related concussion over the study period (2000–2003). Most of the patients (n  =  424, 71.6%) were male, with half (n  =  304, 51.4%) being older than 10 years of age. A total of 152 (25.7%) cases of CHI were related to playing sports. Most cases (71.2%) were mild concussion. The cause of injury was a fall (n  =  322, 54.4%) or a collision. Nearly a quarter of the children (n  =  143, 24.2%) were admitted to hospital, with imaging performed in 134 (22.7%). Most children were treated appropriately and no adverse events were reported.

Conclusions

A severe CHI in a child is six times more likely to have resulted from organised sport than from other leisure physical activities. Outcomes for CHI in children is excellent, although their management places a considerable burden on emergency services. The need for activity restriction and the benefits of this in reducing long term cognitive effects of CHI are uncertain.     

Counselling increases physical activity behaviour nine weeks after rehabilitation

Background

For people with disabilities, a physically active lifestyle can reduce the risk of secondary health problems and improve overall functioning.

Objectives

To determine the effects of the sport stimulation programme “rehabilitation and sports” (R&S) and R&S combined with the daily physical activity promotion programme “active after rehabilitation” (AaR) on sport participation and daily physical activity behaviour nine weeks after inpatient or outpatient rehabilitation.

Methods

Subjects in four intervention rehabilitation centres were randomised to a group receiving R&S only (n  =  315) or a group receiving R&S and AaR (n  =  284). Subjects in six control rehabilitation centres (n  =  603) received the usual care. Most common diagnoses were stroke, neurological disorders, and back disorders. Two sport and two daily physical activity outcomes were assessed with questionnaires seven weeks before and nine weeks after the end of rehabilitation. Data were analysed by intention to treat and on treatment multilevel analyses, comparing both intervention groups with the control group.

Results

The R&S group showed no significant change. Intention to treat analyses of the R&S+AaR group showed significant improvements in one sport (p  =  0.02) and one physical activity outcome (p  =  0.03). On treatment analyses in the R&S+AaR group showed significant improvements in both sport outcomes (p<0.01 and p  =  0.02) and one physical activity outcome (p<0.01).

Conclusions

Only the combination of R&S and AaR had increased sports participation and daily physical activity behaviour nine weeks after the end of inpatient or outpatient rehabilitation.     

Reversal in fatigued athletes of a defect in interferon gamma secretion after administration of Lactobacillus acidophilus

Background

Fatigue and impaired performance in athletes is well recognised and has been loosely linked to “overtraining”. Reduced concentration of IgA in the saliva and increased shedding of Epstein Barr virus (EBV) have been associated with intense training in elite athletes.

Objective

To determine whether athletes presenting with fatigue and impaired performance had an immune defect relevant to defective containment of EBV infection, and whether a probiotic preparation (Lactobacillus acidophilus) shown to enhance mucosal immunity in animal models could reverse any detected abnormality.

Results

The fatigued athletes had clinical characteristics consistent with re‐activation of EBV infection and significantly (p  =  0.02) less secretion of interferon (IFN) γ from blood CD4 positive T cells. After one month of daily capsules containing 2 × 10¹⁰ colony forming units of L acidophilus, secretion of IFNγ from T cells had increased significantly (p  =  0.01) to levels found in healthy control athletes. A significant (p  =  0.03) increase in salivary IFNγ concentrations in healthy control athletes after the one month course of L acidophilus demonstrated in man the capacity for this probiotic to enhance the mucosal IFNγ concentration.

Conclusion

This is the first evidence of a T cell defect in fatigued athletes, and of its reversal following probiotic therapy.     

Serum concentrations of two biochemical markers of brain tissue damage S-100B and neurone specific enolase are increased in elite female soccer players after a competitive game

Background

It is a matter of debate whether or not ordinary heading of the ball in soccer causes injury to brain tissue.

Objective

To analyse concentrations of the biochemical markers of brain tissue damage S‐100B and neurone specific enolase (NSE) in serum of female elite soccer players in association with a competitive game.

Methods

Venous blood samples were obtained from 44 female soccer players before and after a competitive game for analysis. The number of headers and trauma events (falls, collisions, etc) was assessed from videotape recordings for each player.

Results

Concentrations of both brain damage markers were increased after the game (S‐100B, 0.18 (0.11) v 0.11 (0.05) μg/l (p  =  0.000); NSE, 10.14 (1.74) v 9.05 (1.59) μg/l (p  =  0.001)). There was a significant correlation between changes in S‐100B concentrations and both the number of headers (r  =  0.430, p  =  0.004) and the number of other trauma events (r  =  0.517, p<0.001).

Conclusion

The concentrations of both S‐100B and NSE were increased by game associated activities and events. The increases in S‐100B concentration were significantly related to the number of headers and other trauma events, which indicates that both these factors may have contributed to these increases.     

The big finger: the second to fourth digit ratio is a predictor of sporting ability in women

Background

The second to fourth finger length ratio (2d:4d) is thought to be related to diverse traits including cognitive ability, disease susceptibility, and sexuality.

Objective

To examine the relationship between 2d:4d and sports ability in women.

Methods

Hand radiographs from 607 women (mean age 54 years) were used to estimate 2d:4d. Ranking of sports ability was on a scale (1–5).

Results

The highest achieved level of participation in any sport was significantly negatively associated with 2d:4d (b  =  −4.93, p  =  0.01) as was the relationship between 2d:4d and running level (b  =  −6.81, p  =  0.034). Ability in other sports also showed a negative relationship albeit non‐significant.

Conclusions

These results suggest that a low 2d:4d ratio is related to increased female sports ability. It can be postulated that this ratio may predict potential sports ability. Understanding the mechanisms underpinning this relationship may give important insights into musculoskeletal fitness, health and disease.     

A multidisciplinary selection model for youth soccer: the Ghent Youth Soccer Project

Objectives

To determine the relationships between physical and performance characteristics and level of skill in youth soccer players aged 12–16 years.

Methods

Anthropometry, maturity status, functional and sport‐specific parameters were assessed in elite, sub‐elite, and non‐elite youth players in four age groups: U13 (n = 117), U14 (n = 136), U15 (n = 138) and U16 (n = 99).

Results

Multivariate analyses of covariance by age group with maturity status as the covariate showed that elite players scored better than the non‐elite players on strength, flexibility, speed, aerobic endurance, anaerobic capacity and several technical skills (p<0.05). Stepwise discriminant analyses showed that running speed and technical skills were the most important characteristics in U13 and U14 players, while cardiorespiratory endurance was more important in U15 and U16 players. The results suggest that discriminating characteristics change with competitive age levels.

Conclusions

Characteristics that discriminate youth soccer players vary by age group. Talent identification models should thus be dynamic and provide opportunities for changing parameters in a long‐term developmental context.     

Ibuprofen does not affect serum electrolyte concentrations after an ultradistance run

Objective

To determine the effects of ibuprofen on serum electrolyte concentrations after a 160 km running race.

Methods

Twenty nine subjects (mean (SD) age 47.9 (7.4) years) ingested 600 mg ibuprofen the day before, and 1200 mg ibuprofen during, a 160 km competitive trail running race (approximately every 4 h in 200 mg doses). Twenty five control subjects (mean (SD) age 46.8 (10.3) years) avoided ingestion of ibuprofen before or during the race. Blood was drawn on the day before the race and immediately after the race. Serum biochemical profiles were analysed by a clinical laboratory. Significant effects of treatment and time were determined with a general linear model with repeated measures.

Results

Subjects in the two groups did not differ by age, training volume, race experience, body mass index, body fat, or finishing time (25.8 (3.3) vs 25.6 (3.9) h). Body weight did not change significantly over the race (measured before, mid‐race (90 km), and after). Ibuprofen ingestion did not significantly affect any of the serum markers including creatine kinase (p = 0.16). A significant decrease in serum sodium (p = 0.006), potassium (p = 0.001), chloride (p<0.001), calcium (p<0.001), albumin (p<0.001) and globulin (p<0.001) was observed after the race. Increases were seen in creatine kinase (p<0.001), creatinine (p<0.001), blood urea nitrogen (p<0.001), uric acid (p<0.001) and glucose (p<0.001) as the result of the race.

Conclusions

These data suggest that the non‐specific cyclo‐oxygenase inhibitor, ibuprofen, does not alter serum electrolyte concentrations during ultradistance running. However, the stress of ultradistance running appears to be related to significant changes in certain serum markers.     

Proton pump inhibition prevents gastrointestinal bleeding in ultramarathon runners: a randomised, double blinded, placebo controlled study

Background

Ultra‐endurance running is emerging as a popular sport in Western industrialised countries. Gastrointestinal bleeding has been reported to be an adverse effect in these runners.

Objective

To see if the oral administration of a proton pump inhibitor would reduce the incidence of gastrointestinal bleeding in an ultramarathon.

Methods

In a randomised, double blinded, placebo controlled study, a prophylactic regimen of three days of an oral proton pump inhibitor (pantoprazole 20 mg) was tested in healthy athletes participating in the Spartathlon ultramarathon. The incidence of gastrointestinal bleeding was assessed by a stool guaiac test.

Results

Results were obtained for 70 healthy volunteers. The data for 20 of 35 runners in the intervention group and 17 of 35 runners in the placebo group were entered into the final analysis. At the end of the ultramarathon, two subjects in the intervention group and 12 in the placebo group had positive stool guaiac tests (risk difference 0.86; 95% confidence interval 0.45 to 0.96; p  =  0.001).

Conclusion

A short prophylactic regimen of oral proton pump inhibition can successfully decrease the incidence of gastrointestinal bleeding in participants in an ultramarathon.     

Aerobic capacity and peak power output of elite quadriplegic games players

Background

Participation in wheelchair sports such as tennis and rugby enables people with quadriplegia to compete both individually and as a team at the highest level. Both sports are dominated by frequent, intermittent, short term power demands superimposed on a background of aerobic activity.

Objective

To gain physiological profiles of highly trained British quadriplegic athletes, and to examine the relation between aerobic and sprint capacity.

Methods

Eight male quadriplegic athletes performed an arm crank exercise using an ergometer fitted with a Schoberer Rad Messtechnik (SRM) powermeter. The sprint test consisted of three maximum‐effort sprints of five seconds duration against a resistance of 2%, 3%, and 4% of body mass. The highest power output obtained was recorded (PPO). Peak oxygen consumption (V̇o_2peak), peak heart rate (HR_peak), and maximal power output (PO_aer) were determined.

Results

Mean PO_aer was 67.7 (16.2) W, mean V̇o_2peak was 0.96 (0.17) litres/min, and HR_peak was 134 (19) beats/min for the group. There was high variability among subjects. Peak power over the five second sprint for the group was 220 (62) W. There was a significant correlation between V̇o_2peak (litres/min) and PO_aer (W) (r  =  0.74, p<0.05).

Conclusions

These British quadriplegic athletes have relatively high aerobic fitness when compared with the available literature. Moreover, the anaerobic capacity of these athletes appeared to be relatively high compared with paraplegic participants.     

High incidence of exercise-induced bronchoconstriction in triathletes of the Swiss national team

Aim

To assess the progression of bronchial reactivity (BR) and incidence of bronchial hyperreactivity (BH), exercise‐induced bronchoconstriction (EIB) and asthma in triathletes over 2 years.

Methods

Subjects were seven athletes from the Swiss national triathlon team (mean (SD) age 24.3 (4.8) years), who initially were not asthmatic, not treated with antiasthmatic medication, and who had performed at international level for more than 3 consecutive years (2001–2003). To assess BR, BH and EIB, subjects ran on a 400 m track for 8 min at intensities equal to the anaerobic threshold. Tests were conducted in ambient temperatures of 4.4 (2.8)°C, –8.8 (2.4)°C and 3.6 (1.5)°C, and humidity of 52 (16)%, 83 (13)% and 93 (2)%. Forced expiratory volume in 1 s (FEV₁) was measured before and at 2, 5, 10 and 15 min after EIB, and 5 min after inhalation of a β2 agonist. Two methods were used to calculate the incidence: (1) the standard assessment; (2) extrapolation of the decrease in FEV₁ to the BH limit.

Results

BR increased significantly in the seven athletes (FEV₁: year, p = 0.04; year × EIB, p = 0.002; EIB p<0.001). Within 2 years, BR had increased significantly and even reached BH in some athletes. Three athletes exhibited BH. After extrapolation of the decrease in FEV₁ in all seven athletes, the limit of 10% by definition for BH was determined to occur within 1.77–4.81 years, resulting in 21–57% of athletes with newly developed BH per year.

Conclusion

Athletes develop EIB quickly, a rate of increase 195–286 times that of the normal rate for development of asthma.     

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 5×8 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.     

Left ventricular chamber size predicts the race time of Japanese participants in a 100 km ultramarathon

Objective

As a subanalysis of an echocardiographic study performed on 291 Japanese participants in a 100 km ultramarathon, to estimate predictors of race time.

Methods

A total of 247 male participants in a 100 km ultramarathon (age 20–73 years) were examined by echocardiography. Correlations between age, body surface area, monthly running distance, or echocardiographic variables and the race time were examined.

Results

According to simple regression analysis, age (r  =  0.299, p<0.0001), monthly running distance (r  =  −0.388, p<0.0001), left ventricular end diastolic diameter (r  =  −0.300, p<0.0001), and left ventricular end systolic diameter (r  =  −0.325, p<0.0001) correlated significantly with the race time. When multiple regression analysis was performed, age (f  =  2.364), monthly running distance (f  =  −0.113), and left ventricular end systolic diameter (f  =  −2.361) remained significant predictors of the race time.

Conclusion

Left ventricular diameter predicts the race time for a 100 km ultramarathon, in addition to age and amount of training.     

Raised troponin T and echocardiographic abnormalities after prolonged strenuous exercise--the Australian Ironman Triathlon

Background

There is concern about whether cardiac damage occurs as a result of prolonged strenuous exercise.

Objective

To investigate whether competing in a triathlon is associated with cardiac damage based on a sustained increase in cardiac troponin T (cTnT), and whether such an increase correlates with echocardiographic changes

Methods

cTnT and echocardiographic measurements were made in 38 participants in the 2001 Australian ironman triathlon. cTnT was measured the day before, immediately after, and the day following the race. Echocardiography was done the day before, immediately after, and two to six weeks later for measurement of ejection fraction, stroke volume, cardiac output, wall motion analysis, and global left ventricular function (LVF).

Results

No subject had detectable cTnT in the pre‐race sample. Following the race, 32 subjects (86.5%) had detectable levels of cTnT (>0.01 ng/ml), with six (16.2%) having >0.10 ng/ml. The day after the race, nine subjects (23.7%) still had detectable cTnT, with two recording a level >0.10 ng/ml. Previously described echocardiographic changes of “cardiac fatigue” were observed in the whole cohort. There was a modest but significant correlation between change in ejection fraction and peak cTnT level (p = 0.02, r = 0.39). Athletes with a post‐race cTnT >0.10 ng/ml had a greater decrease in global LVF (p = 0.02) and a trend toward a greater fall in ejection fraction and stroke volume than athletes with cTnT levels <0.10 ng/ml. Cardiac output fell in the group with cTnT >0.10 ng/ml (p>0.05).

Conclusions

Participation in ironman triathlon often resulted in persistently raised cTnT levels, and the troponin rise was associated with echocardiographic evidence of abnormal left ventricular function. The clinical significance and long term sequelae of such damage remains to be determined.     

A randomised, placebo controlled trial of low level laser therapy for activated Achilles tendinitis with microdialysis measurement of peritendinous prostaglandin E2 concentrations

Background

Low level laser therapy (LLLT) has gained increasing popularity in the management of tendinopathy and arthritis. Results from in vitro and in vivo studies have suggested that inflammatory modulation is one of several possible biological mechanisms of LLLT action.

Objective

To investigate in situ if LLLT has an anti‐inflammatory effect on activated tendinitis of the human Achilles tendon.

Subjects

Seven patients with bilateral Achilles tendinitis (14 tendons) who had aggravated symptoms produced by pain inducing activity immediately before the study.

Method

Infrared (904 nm wavelength) LLLT (5.4 J per point, power density 20 mW/cm²) and placebo LLLT (0 J) were administered to both Achilles tendons in random blinded order.

Results

Ultrasonography Doppler measurements at baseline showed minor inflammation through increased intratendinous blood flow in all 14 tendons and measurable resistive index in eight tendons of 0.91 (95% confidence interval 0.87 to 0.95). Prostaglandin E₂ concentrations were significantly reduced 75, 90, and 105 minutes after active LLLT compared with concentrations before treatment (p  =  0.026) and after placebo LLLT (p  =  0.009). Pressure pain threshold had increased significantly (p  =  0.012) after active LLLT compared with placebo LLLT: the mean difference in the change between the groups was 0.40 kg/cm² (95% confidence interval 0.10 to 0.70).

Conclusion

LLLT at a dose of 5.4 J per point can reduce inflammation and pain in activated Achilles tendinitis. LLLT may therefore have potential in the management of diseases with an inflammatory component.