Triathlon related musculoskeletal injuries: The status of injury prevention knowledge

Injury and illness in short-course triathletes: A systematic review

BACKGROUND

Determining the incidence and prevalence of injury and illness in short-course triathletes would improve understanding of their etiologies and therefore assist in the development and implementation of prevention strategies. This study synthesizes the existing evidence on the incidence and prevalence of injury and illness and summarizes reported injury or illness etiology and risk factors affecting short-course triathletes.

METHODS

This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies reporting health problems (injury and illness) in triathletes (all sexes, ages, and experience levels) training and/or competing in short-course distances were included. Six electronic databases (Cochrane Central Register of Controlled Trials, MEDLINE, Embase, APA PsychINFO, Web of Science Core Collection, and SPORTDiscus) were searched. Risk of bias was independently assessed by 2 reviewers using the Newcastle-Ottawa Quality Assessment Scale. Two authors independently completed data extraction.

RESULTS

The search yielded 7998 studies, with 42 studies eligible for inclusion. Twenty-three studies investigated injuries, 24 studies investigated illnesses, and 5 studies investigated both injuries and illnesses. The injury incidence rate ranged 15.7-24.3 per 1000 athlete exposures, and the illness incidence rate ranged 1.8-13.1 per 1000 athlete days. Injury and illness prevalence ranged between 2%-15% and 6%-84%, respectively. Most injuries reported occurred during running (45%-92%), and the most frequently reported illnesses affected the gastrointestinal (7%-70%), cardiovascular (14%-59%), and respiratory systems (5%-60%).

CONCLUSION

The most frequently reported health problems in short-course triathletes were: overuse and lower limb injuries associated with running; gastrointestinal illnesses and altered cardiac function, primarily attributable to environmental factors; and respiratory illness mostly caused by infection.

Injury incidence and prevalence in elite short-course triathletes: a 4-year prospective study

OBJECTIVE

To characterise the prevalence, incidence rate (IR) and burden of injuries in elite short-course triathletes over a 4-year training and competition period.

METHODS

Fifty elite Australian triathletes were prospectively monitored for injury during four consecutive seasons (2018-2021). Injuries requiring medical attention were prospectively recorded and further subcategorised according to time loss. The IR and burden (injury IR×mean injury severity) were calculated per 365 athlete days, with sex differences in IR compared using IR ratios (IRR) from negative binomial regression models.

RESULTS

Two hundred and sixty-six injuries were reported in 46 (92.0%) athletes, of which 67.3% resulted in time loss. The injury IR was 1.87 injuries per 365 athlete days (95% CI 1.70 to 2.80), and comparable between sexes (IRR 0.82, 95% CI 0.64 to 1.04, p=0.109). Most injuries (70.7%) were training related. The most frequently injured body sites were the ankle (15.8%), foot (12.4%) and lower leg (12.0%). Bone stress injuries (BSIs) were the most burdensome injury type with 31.38 days of time loss per 365 days (95% CI 24.42 to 38.34). Twenty athletes (40.0%) reported at least one bone stress injury (BSI) (range 0-3). The rate of BSIs in female athletes was three times greater compared with male athletes (IRR 2.99, 95% CI 1.26 to 7.07, p=0.013).

CONCLUSION

Two-thirds of injuries reported in elite short-course triathletes resulted in time loss, with the majority occurring during training activities. Foot, ankle and other lower leg injuries had the highest incidence, with BSIs carrying the highest injury burden. The considerably higher rate of BSI observed in female athletes warrants consideration for future prevention strategies in female triathletes.

Athlete monitoring practices in elite sport in the United Kingdom

Athlete monitoring systems (AMS) aid performance optimisation and support illness/injury prevention. Nonetheless, limited information exists on how AMS are employed across elite sports in the United Kingdom. This study explored how athlete monitoring (AM) data, in particular athlete self-report measures, were collected, analysed and disseminated within elite sports. Thirty elite sports practitioners representing 599 athletes responded to a survey on their AM methodologies. The majority, 83%, (n = 25) utilised an AMS, and a further 84% (n = 21) stated the collection of their AMS data was underpinned by a scientific rationale. Athlete self-report measures (ASRM) were the most commonly employed tool, with muscle soreness, sleep and energy levels amongst the most frequently collected measures. The ubiquitous use of custom single-item ASRM resulted in considerable variability in the questionnaires employed, thus potentially impacting questionnaire validity. Feedback processes were largely felt to be ineffective, with 44% (n = 11) respondents indicating that athletes did not receive sufficient feedback. Some respondents indicated that AMS data was never discussed with athletes and/or coaches. Overall, significant disparities exist in the use of athlete monitoring systems between research and elite sports practice, and the athlete, coach and practitioner experience of monitoring risks being poor if these disparities are not addressed.

Injuries in Medium to Long-Distance Triathlon: A Retrospective Analysis of Medical Conditions Treated in Three Editions of the Ironman Competition

Triathlon's popularity is rapidly increasing, and epidemiological data relating to its related medical conditions is crucial to the development of proper medical plans and safety guidelines for it. This study examined the data from the medical reports collected during three consecutive editions of Ironman Italy, from 2017 to 2019. Out of 10,653 race-starters, 3.3% required medical attention sustaining 472 medical conditions. A significantly higher injury risk was found for females versus males (χ2 = 9.78, p = 0.02) and in long-distance (IR: 4.09/1,000hours) rather than in Olympic/middle distance races (IR: 1.75/1,000hours). Most (68.4%) conditions (including muscular exhaustion, hypothermia, and dehydration) were systemic, whilst only 10.2% were acute traumatic injuries. Of a total of 357 triathletes requiring medical assistance, 8.1% were a candidate for hospitalisation. The equipment and personnel that are required for the medical assistance in future triathlon events were estimated based on Maurer's algorithm, and ten practical recommendations for triathlon medical support were formulated.

A Systematic Review of Long‐Distance Triathlon Musculoskeletal Injuries

The distribution of injuries affecting long-distance triathletes is yet to be fully understood. A systematic review was performed of the clinical literature to determine the epidemiology of musculoskeletal injuries affecting long-distance triathletes. Searched databases in Feb 2020 were PubMed, Medline, EMBASE, EMCARE, and CINHAL databases. Published observational research articles related to the incidence or prevalence of musculoskeletal injuries in long-distance triathletes (competing at “Ironman” full distance or greater), written in the English language and not restricted by age or gender or date were eligible. Of the 975 studies identified on the initial search, six studies met the inclusion criteria for analysis. The mean age (SD) of the long-distance triathletes in these studies was 35.1 (2.7) and the range was 21-68 years. Overuse injuries were most frequent with the incidence range of 37-91%, and acute injury incidence range was 24-27%. The knee and spine were the most frequent location of injury. Running and cycling were the most frequently affected disciplines. Elite athletes had a lower incidence of overuse injury (37%). The highest acute injury incidence (27%) was recorded in non-elite athletes. The quality of the studies was relatively poor with only one study satisfying >50% of the quality assessment tool questions and only two studies were prospective, the rest were retrospective cross-sectional studies. Overall, there is a lack of literature reporting on musculoskeletal injuries in long-distance triathletes. Overuse injuries, particularly in the knee, are the most frequently reported, running and cycling are the most frequent disciplines associated. Long-distance triathletes may have a lower incidence of both overuse and acute injuries.

Triathlon Considerations

Triathlon is an increasingly popular sport that includes swimming, cycling, followed by running. The triathlete should not be seen merely as a cyclist who also swims and runs. Notable differences are seen in the type of bike used, training patterns, lower extremity demands, and cumulative nature of the sport. Injury prevention and treatment strategies need to take into account the triathlon distance, the type of bike used, athletic experience, prior injuries, risk factors, and a thorough understanding of the demands placed on the body through all 3 disciplines (swim, bike, and run).

Epidemiology of Musculoskeletal Injuries in Adult Athletes: A Scoping Review

Background and Objectives: Sport-related musculoskeletal injuries (MSK-Is) are a common health issue in athletes that can lead to reduced performance. The aim of this scoping review was to synthetize available evidence on injury incidence rates (IIRs), types, and sites that affect the musculoskeletal (MSK) system of adult athletes. Materials and Methods: We performed a scoping review on the Pubmed database limiting our search to 33 Olympic sports. Results: We identified a total of 1022 papers, and of these 162 were examined in full for the purpose of this review. Archery was the sport with the highest risk of injuries to the upper extremities, marathons for the lower extremities, and triathlon and weightlifting for the body bust. In the majority of the sports examined, muscle/tendon strain and ligament sprain were the most common MSK-Is diagnoses, while athletics, karate, and football were the sports with the highest IIRs, depending on the methods used for their calculations. Conclusions: Our scoping review highlighted the general lack and dishomogeneity in the collection of data on MSK-Is in athletes.

Bilateral in vivo neuromechanical properties of the triceps surae and Achilles tendon in runners and triathletes

Inter-limb differences in Achilles tendon mechanical, material and morphological properties have previously been described in non-athletes and attributed to the preferential use of a given limb. Achilles tendon overuse tendon injury generally initiate unilaterally and alters triceps surae activation and Achilles tendon properties. The investigation of inter-limb differences in muscle activation and tendon properties may provide directions for injury prevention in habitual runners. In this study triceps surae and Achilles tendon properties were investigated bilaterally in habitual runners during unilateral maximal isometric contractions. Morphological, mechanical and material Achilles tendon properties were assessed using isokinetic dynamometry, motion capture and ultrasonography while triceps surae activation strategies were assessed using electromyography. Lower limb preference was assessed for inter-limb comparisons using the Waterloo questionnaire. Zero and one-dimensional statistical analysis and Cohen's d were employed to investigate possible inter-limb differences. Inter-limb associations in Achilles tendon properties and intra-limb associations between triceps surae activations were assessed using Pearson's correlation coefficients. No differences were observed between the preferred and non-preferred limb in terms of triceps surae muscle activation amplitude and Achilles tendon properties. However, intra-limb association among triceps surae activation ratios were not identical between limbs. Runners and triathletes present similar Achilles tendons properties between limbs, and thus initial observations of unilateral changes in the Achilles tendon properties might be used as a strategy to prevent the onset of overuse tendon injury. The non-similar associations within activation ratios between limbs should be further explored since triceps surae activation strategies may alter loading of the Achilles tendon.

Running after cycling induces inter-limb differences in muscle activation but not in kinetics or kinematics

Overuse injuries are a common problem to triathletes' population. Overuse injuries may arise from inter-limb biomechanical differences during running, but the literature lacks information regarding inter-limb differences in triathletes. In this study inter-limb differences were investigated in injury-free triathletes during the running portion of a simulated cycle-run transition. Thirteen triathletes performed a 5 km run preceded by a 20 min cycling trial at 70% of maximal power output. During the Start, Mid and End stages of running, kinetic, kinematic and muscle activation variables were compared between the preferred and non-preferred limbs across the stance phase. A statistical parametric mapping analysis showed no differences between limbs when considering kinetic and kinematic variables (p > 0.05, ES<0.60). A lower soleus activation was observed in the preferred limb (p < 0.05, ES>0.60) from 53.40-75.9% of the stance phase at the End stage of running. In conclusion, inter-limb differences in kinetic or kinematic variables may not represent a risk for overloading in triathletes. However, inter-limb differences in triceps surae activation during running after cycling may represent one potential factor leading to overuse injuries in triathletes and should be further investigated.

Running status and history: A self-report study

OBJECTIVES

The purpose of the current study was to compare injury and running history among current and former runners who consider themselves either injured or uninjured.

DESIGN

Cross-sectional survey.

SETTING

Online survey, available to any individuals over the age of 18 who currently run (runners) or who once ran regularly but are no longer running (former runners).

PARTICIPANTS

312 participants (age 38 ± 12 years, 219 males, 89 females, 4 did not disclose) completed the survey.

MAIN OUTCOME MEASURES

This study assessed injury incidence, consequences of injury such as time off, and reported injury diagnoses and treatments. Chi-square and frequency analyses were calculated to describe running status, injury counts, and response to injury.

RESULTS

Most participants (80%) reported 1 + running injury. 775 total injuries were reported. The four most common injuries were iliotibial band syndrome (34%), plantar fasciitis (30%), strained thigh/hip muscle (25%), and medial tibial stress syndrome (22%). About 40% of participants continued to run with these injuries.

CONCLUSIONS

Injury frequencies (80%) agreed with those reported in the literature. The results of this study also support the notion that running injuries exist on a continuum of severity and that the individual response to injury is complex and determined by various factors.

Risk factors for acute injuries and overuse syndromes of the shoulder in amateur triathletes - A retrospective analysis

Objectives

To investigate the prevalence of shoulder-related acute and overuse injuries in triathletes and examine the role of possible risk factors, in order to identify potential preventive measures.

Methods

We performed a retrospective epidemiologic study of 193 amateur triathletes between June and August 2013 and evaluated their competition and training habits, as well as the presence of acute and overuse injuries of the shoulder sustained during the past 12 months. Contingency tables were analyzed using Pearson’s chi-squared test. Normally distributed data were compared with the independent samples t-test, while non-parametric analyses were performed with the Mann-Whitney U test. Binary logistic regression was used to identify important predictors of injuries.

Results

12 participants (6%) sustained acute injuries and 36 athletes experienced an overuse injury. The acute injury rate amounted to 0.11 per 1000 hours of training and the overuse injury rate to 0.33 per 1000 hours of training. There was no association between athletes’ age, height, weight, BMI, a history of shoulder complaints or triathlon experience in years and acute or overuse injuries. Male athletes had a trend for sustaining more acute injuries then female athletes (8% vs. 2%, p = 0.079). Athletes with acute injuries spent a significantly higher amount of time per week doing weight training (p = 0.007) and had a trend for a higher weekly duration of cycling training (p = 0.088). Athletes with overuse injuries participated in a significantly higher number of races compared to athletes without overuse injuries (p = 0.005). The regular use of paddles was associated with a significantly higher rate of overuse injuries (24% vs. 10%, p = 0.014).

Conclusion

The regular use of paddles during swimming training appears to be a risk factor for the development of overuse injuries, while an increased duration of weight and cycling training seems to be associated with a higher rate of acute injuries.

Massage therapy decreases pain and perceived fatigue after long-distance Ironman triathlon: a randomised trial

QUESTION

Can massage therapy reduce pain and perceived fatigue in the quadriceps of athletes after a long-distance triathlon race (Ironman)?

DESIGN

Randomised, controlled trial with concealed allocation, intention-to-treat analysis and blinded outcome assessors.

PARTICIPANTS

Seventy-four triathlon athletes who completed an entire Ironman triathlon race and whose main complaint was pain in the anterior portion of the thigh.

INTERVENTION

The experimental group received massage to the quadriceps, which was aimed at recovery after competition, and the control group rested in sitting.

OUTCOME MEASURES

The outcomes were pain and perceived fatigue, which were reported using a visual analogue scale, and pressure pain threshold at three points over the quadriceps muscle, which was assessed using digital pressure algometry.

RESULTS

The experimental group had significantly lower scores than the control group on the visual analogue scale for pain (MD -7 mm, 95% CI -13 to -1) and for perceived fatigue (MD -15 mm, 95% CI -21 to -9). There were no significant between-group differences for the pressure pain threshold at any of the assessment points.

CONCLUSION

Massage therapy was more effective than no intervention on the post-race recovery from pain and perceived fatigue in long-distance triathlon athletes.

TRIAL REGISTRATION

Brazilian Registry of Clinical Trials, RBR-4n2sxr.

The impact of triathlon training and racing on athletes' general health

Although the sport of triathlon provides an opportunity to research the effect of multi-disciplinary exercise on health across the lifespan, much remains to be done. The literature has failed to consistently or adequately report subject age group, sex, ability level, and/or event-distance specialization. The demands of training and racing are relatively unquantified. Multiple definitions and reporting methods for injury and illness have been implemented. In general, risk factors for maladaptation have not been well-described. The data thus far collected indicate that the sport of triathlon is relatively safe for the well-prepared, well-supplied athlete. Most injuries 'causing cessation or reduction of training or seeking of medical aid' are not serious. However, as the extent to which they recur may be high and is undocumented, injury outcome is unclear. The sudden death rate for competition is 1.5 (0.9-2.5) [mostly swim-related] occurrences for every 100,000 participations. The sudden death rate is unknown for training, although stroke risk may be increased, in the long-term, in genetically susceptible athletes. During heavy training and up to 5 days post-competition, host protection against pathogens may also be compromised. The incidence of illness seems low, but its outcome is unclear. More prospective investigation of the immunological, oxidative stress-related and cardiovascular effects of triathlon training and competition is warranted. Training diaries may prove to be a promising method of monitoring negative adaptation and its potential risk factors. More longitudinal, medical-tent-based studies of the aetiology and treatment demands of race-related injury and illness are needed.

Treatment of lateral knee pain using soft tissue mobilization in four female triathletes

STUDY DESIGN

Prospective case series.

BACKGROUND

These case reports present results of the treatment of lateral knee pain in four female amateur triathletes. The athletes were referred to the author's clinic with either a diagnosis of iliotibial band friction syndrome or patellofemoral pain syndrome, all four having symptoms for longer than seven months. Changes in training routines were identified as the possible cause of the overuse injuries that eventually developed into chronic conditions.

INTERVENTION

Treatment involved soft tissue mobilization of the musculotendinous structures on the lateral aspect of the knee.

RESULTS

At four weeks, three of the athletes improved 9 to 19 points on the Lower Extremity Functional Scale, 3 to 5 points on the Global Rating of Change Scale, and demonstrated improvement in hamstring and iliotibial band flexibility. At eight weeks the Global Rating of Change for these three athletes was a 7 ("a very great deal better") and they had returned to triathlon training with no complaints of lateral knee pain. One athlete did not respond to treatment and eventually underwent arthroscopic surgery for debridement of a lateral meniscus tear.

CONCLUSIONS

After ruling out common causes for lateral knee pain such as lateral meniscus tear, lateral collateral ligament sprain, patellofemoral dysfunction, osteochondral injury, biceps femoris tendonitis, iliotibial band friction syndrome or osteoarthritis, soft tissue restriction should be considered a potential source of dysfunction. In some cases soft tissue restriction is overlooked; athletes go undiagnosed and are limited from sports participation.

The perception of injury risk and safety in triathlon competition: an exploratory focus group study

OBJECTIVE

To explore stakeholder perceptions of triathlon competition safety and injury risk.

DESIGN

Qualitative focus group study.

SETTING

Triathlon stakeholders from Melbourne, Australia.

PARTICIPANTS

Competition organizers, coaches, and competitors of various skill levels, age, gender, and experience (n = 18).

INTERVENTIONS

Focus groups were conducted, recorded, and transcribed for analysis.

MAIN OUTCOME MEASURES

Key themes were identified using content analysis.

RESULTS

The perceived risk of serious injury was highest for cycling. Running was most commonly linked to minor injuries. Physical and environmental factors, including course turning points, funneling of competitors into narrow sections, and the weather, were perceived as contributing to injury. Experience, skill level, feelings of vulnerability, personal awareness, club culture, and gender issues were perceived as the competitor-related factors potentially contributing to injury. The cycling mount/dismount area, cycling, and swim legs were the race sections perceived as the riskiest for competitors. Competition organizers were considered to generally have the competitors' best interest as a priority. Triathlons were acknowledged as risky activities and individual competitors accepted this risk.

CONCLUSIONS

This study has highlighted the main risks and concerns perceived by triathlon competitors, coaches, and competition organizers, which will help identify potential, context-relevant intervention strategies to reduce injury risk.

Health professionals' perceptions of musculoskeletal injury and injury risk factors in Australian triathletes: a factor analysis

OBJECTIVE

This study investigated health professional perceptions of triathlon-related injury risk factors and injury prevention strategies, to inform prospective cohort studies investigating injury in triathletes.

DESIGN

Exploratory factor analysis.

METHODS

A questionnaire was developed and distributed to Australian sports medicine health professionals (n = 504). Information was collected about their perceptions of factors contributing to injury and injury prevention strategies relating to Sprint/Olympic (S/O) and Ironman/Long Course (I/LC) athletes. Factor analysis was performed to identify the number and nature of the constructs (factors) underlying the responses to the questions, and to ascertain whether these factors were similar for S/O and I/LC athletes.

RESULTS

The response rate was 22.4% (n = 113). Five factors were extracted for injury risk accounting for 53% (S/O) and 56% (I/LC) of the variance. The factors were common across S/O and I/LC groups; biomechanics and technique, training factors, demographics, injury prevention and personal factors. Three common factors accounted for 54% (S/O) and 55% (I/LC) of the variance for injury prevention strategies; designated training regimes, health and medical monitoring and preparation of the triathlete.

CONCLUSIONS

These results indicate that future studies into triathlon injuries should include, at a minimum, detailed training load and demographic factors to test their impact as injury risk factors in triathlete populations.

Isokinetic analysis of ankle and ground reaction forces in runners and triathletes

OBJECTIVE

To analyze and compare the vertical component of ground reaction forces and isokinetic muscle parameters for plantar flexion and dorsiflexion of the ankle between long-distance runners, triathletes, and nonathletes.

METHODS

Seventy-five males with a mean age of 30.26 (±6.5) years were divided into three groups: a triathlete group (n=26), a long-distance runner group (n = 23), and a non-athlete control group. The kinetic parameters were measured during running using a force platform, and the isokinetic parameters were measured using an isokinetic dynamometer.

RESULTS

The non-athlete control group and the triathlete group exhibited smaller vertical forces, a greater ground contact time, and a greater application of force during maximum vertical acceleration than the long-distance runner group. The total work (180º/s) was greater in eccentric dorsiflexion and concentric plantar flexion for the non-athlete control group and the triathlete group than the long-distance runner group. The peak torque (60º/s) was greater in eccentric plantar flexion and concentric dorsiflexion for the control group than the athlete groups.

CONCLUSIONS

The athlete groups exhibited less muscle strength and resistance than the control group, and the triathletes exhibited less impact and better endurance performance than the runners.

Extremely short duration high-intensity training substantially improves endurance performance in triathletes

High-intensity training (HIT) involving 30-s sprints is an effective training regimen to improve aerobic performance. We tested whether 6-s HITs can improve aerobic performance in triathletes. Six subelite triathletes (age, 40 ± 9 years; weight, 86 ± 11 kg; body mass index, 26 ± 3 kg·m⁻²) took part in cycle HIT and 6 endurance-trained subelite athletes (age, 36 ± 9 years; weight, 82 ± 11 kg; BMI, 26 ± 3 kg·m⁻²) maintained their normal training routine. Before and after 2 weeks of HIT, involving 10 × 6-s sprints or normal activity, participants performed a self-paced 10-km time trial and a time to exhaustion test on a cycle ergometer. Finger prick blood samples were taken throughout the time to exhaustion test to determine blood lactate concentration. Two weeks of HIT resulted in a 10% decrease in self-paced 10-km time trial (p = 0.03) but no significant change in time to exhaustion. The time taken to reach onset of blood lactate accumulation (OBLA, defined as the point where blood lactate reaches 4 mmol·L⁻¹) was significantly increased following 2 weeks of HIT (p = 0.003). The change in time trial performance was correlated to the change in time taken to reach OBLA (R² = 0.63; p = 0.001). We concluded that a very short duration HIT is a very effective training regimen to improve aerobic performance in subelite triathletes and this is associated with a delay in blood lactate build-up.

Cyclists and triathletes have different body positions on the bicycle

Our study evaluated differences in body position on the bicycle for recreational cyclists, competitive cyclists and triathletes. Thirty-six recreational cyclists, 17 competitive road cyclists and 18 competitive triathletes were assessed for body position on their bicycles on a cycle trainer. Images were taken of cyclists/triathletes in static poses with the crank at the 3 o'clock and 6 o'clock positions. Trunk, pelvis, hip, knee and ankle angles, anterior-posterior and medio-lateral positions of the knees in relation to the pedal axis and frontal projected area were measured using ImageJ. Comparison of body position between groups (recreational, competitive road cyclists and competitive triathletes) was conducted using effects sizes (ES). The greatest differences between groups in the measured variables were observed between the triathletes and the other two groups. Smaller differences were observed between competitive and recreational cyclists. Competitive triathletes had greater body forward projection (10% greater trunk flexion and 66% knee anterior position, ES = 2.5 and 1.2, respectively) and less frontal projected area (17%, ES = 1.3) than competitive road cyclists for body position on the bicycle. Both recreational and competitive cyclists sat on their bicycles with their trunks in a more vertical position compared to triathletes. Guidelines for bicycle configuration for triathletes and road cyclists need to consider the body positions during events.

Imaging of triathlon injuries

Injuries in triathletes are common and are mostly overuse injuries. Rotator cuff tendinitis is the most common complaint from swimming, but the incidence of tendinopathy and rotator cuff tears on magnetic resonance imaging is comparable in triathletes without and with shoulder pain. Cycling injuries are mainly to the knee, including patellar tendinosis, iliotibial band syndrome, and patellofemoral stress syndrome, and to the Achilles tendon and the cervical and lumbar spine. Running is associated with most injuries in triathletes, during both training and racing, causing the athlete to discontinue the triathlon. In addition to knee injuries from running, triathletes may also develop foot and ankle, lower leg, and hip injuries similar to single-sport distance runners. Some injuries in triathletes may be mainly symptomatic during one of the three sports but are exacerbated by one or both of the other disciplines.

Efeito do exercício nas concentrações séricas de creatina cinase em triatletas de ultradistância

O triatlo é um esporte de destaque e ampla participação mundial. Incorpora três diferentes modalidades de endurance - natação, ciclismo e corrida - dentro de um único evento. Há uma variedade de distâncias sobre as quais os eventos de triatlo são realizados, sendo a prova de ultradistância (ironman) a mais extensa. Autores diversos já relataram a ocorrência de lesões após esforço intenso, seja diretamente, através de alterações histológicas no sarcômero, ou indiretamente, pela quantificação da concentração de proteínas musculares específicas (biomarcadoras de lesão) no plasma. Entre esses marcadores de lesão muscular destacam-se a mioglobina e a creatina cinase. Efetivamente, a creatina cinase é o indicador bioquímico mais utilizado na literatura como indicador da ocorrência de lesão muscular. Dentro desse contexto justifica-se o objetivo do presente trabalho que visa verificar o efeito do exercício nas concentrações séricas de creatina cinase em triatletas de ultradistância frente a um período de competição. Para tanto, foram avaliados os dados das concentrações séricas de CK de 10 atletas que participaram da prova do Ironman Brasil de 2007. As análises sanguíneas foram realizadas em cinco períodos distintos: 19 dias antes da prova do ironman (CK1), 48 horas antes da prova (CK2), imediatamente após (CK3), cinco dias após (CK4) e 12 dias depois da prova (CK5). Os resultados apontaram aumento significativo nas concentrações de CK nos períodos 3 e 4 em relação aos demais períodos avaliados. Estas alterações evidenciam a influência do exercício exaustivo sobre as concentrações de CK, revelando a possibilidade de desenvolvimento de lesões musculares durante essa competição. Este fato reforça a importância do monitoramento de biomarcadores, como a CK, que permite a treinadores e atletas ajustarem suas cargas de treinamento para aumentar os benefícios do treinamento e para evitar o supertreinamento, melhorando o desempenho, a saúde e a qualidade de vida do atleta.

A profile of injuries in athletes seeking treatment during a triathlon race series

BACKGROUND

Triathlon combines swimming, cycling, and running into a single event. With increasing popularity of this sport, there has been a rise in the number of participants, particularly in shorter distance races. However, the risks of participating in short-distance races have not been reported.

PURPOSE

To describe the rate and profile of injuries seen for medical assistance during a triathlon race series.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

A standardized injury reporting form was used to collect information from race entrants seeking medical aid at each of the races comprising a combination of Sprint, Olympic, and Fun race distances in a triathlon series in Victoria, Australia over the 2006-2007 race season. Injury rates and risk factors were assessed via regression analysis.

RESULTS

There were 10,197 individual starters who took part. There were 235 presentations for medical assistance (n = 322 injuries) over the series. The presentation rate was 20.1 per 1000 hours of competition (2.3% of total race starts). Injuries were predominantly sustained during the run (38.4%) and cycle (14.3%) legs. Lower limb injuries (59.5%) and abrasions (28.6%) were the most common site and nature of injury, respectively. There were 9 severe injuries: 5 fractures, 3 probable heat stroke cases, and 1 deep laceration. Elite/Junior Elite, Olympic distance, and 12- to 19-year-old competitors were at higher risk of injury, especially during running and cycling.

CONCLUSION

The level and age of triathlon competitors, and the race distance, influenced the risk of injury over a race series. These results provide timely information for triathlon race event organizers and could be incorporated into a review of practices for the provision of medical services to triathlon events, especially the common sprint distance competitions.

CLINICAL RELEVANCE

Shorter distance triathlons have lower injury rates and relatively minor injuries, but medical teams and race organizers should be prepared for serious injuries.

Neuromuscular control and exercise-related leg pain in triathletes

Previous studies have shown that cycling can directly influence neuromuscular control during subsequent running in some highly trained triathletes. A relationship between this altered neuromuscular control of running and musculoskeletal pain and injury has been proposed; however, this link has not been investigated.

PURPOSE

This study aimed to evaluate the influence of cycling on neuromuscular control during subsequent running in highly trained triathletes with and without exercise-related leg pain (ERLP).

METHODS

Participants were 34 highly trained triathletes: 10 triathletes with a history of ERLP and 24 training-matched control triathletes with no history of ERLP. Knee and ankle kinematics and leg muscle recruitment were compared between a baseline run (no prior exercise) and a transition run (preceded by cycling; i.e., run vs cycle run).

RESULTS

Knee and ankle joint kinematics were not different between baseline and transition runs for any triathletes: absolute mean difference (+/-95% confidence interval) was 1.49 degrees +/- 0.17 degrees. However, muscle recruitment was different between baseline and transition runs, defined by absolute mean difference in EMG amplitude > or = 10%, in 5 of 24 control triathletes (11/130 muscles exhibited altered recruitment) and in 5 of 10 triathletes with a history of ERLP (12/50 muscles exhibited altered recruitment). This represents a relative risk of 2.40 (0.89-6.50; P = 0.089) when defined by athletes and 2.62 (1.34-6.01; P < 0.01) when defined by muscles. The magnitude of change in muscle recruitment between baseline and transition runs was not different between control (14.10% +/- 2.34%) and ERLP triathletes (16.31% +/- 3.64%; P = 0.41).

CONCLUSIONS

This study demonstrates an association between ERLP in triathletes and their neuromuscular control when running off the bike.

Neuromuscular adaptations to training, injury and passive interventions: implications for running economy

Performance in endurance sports such as running, cycling and triathlon has long been investigated from a physiological perspective. A strong relationship between running economy and distance running performance is well established in the literature. From this established base, improvements in running economy have traditionally been achieved through endurance training. More recently, research has demonstrated short-term resistance and plyometric training has resulted in enhanced running economy. This improvement in running economy has been hypothesized to be a result of enhanced neuromuscular characteristics such as improved muscle power development and more efficient use of stored elastic energy during running. Changes in indirect measures of neuromuscular control (i.e. stance phase contact times, maximal forward jumps) have been used to support this hypothesis. These results suggest that neuromuscular adaptations in response to training (i.e. neuromuscular learning effects) are an important contributor to enhancements in running economy. However, there is no direct evidence to suggest that these adaptations translate into more efficient muscle recruitment patterns during running. Optimization of training and run performance may be facilitated through direct investigation of muscle recruitment patterns before and after training interventions. There is emerging evidence that demonstrates neuromuscular adaptations during running and cycling vary with training status. Highly trained runners and cyclists display more refined patterns of muscle recruitment than their novice counterparts. In contrast, interference with motor learning and neuromuscular adaptation may occur as a result of ongoing multidiscipline training (e.g. triathlon). In the sport of triathlon, impairments in running economy are frequently observed after cycling. This impairment is related mainly to physiological stress, but an alteration in lower limb muscle coordination during running after cycling has also been observed. Muscle activity during running after cycling has yet to be fully investigated, and to date, the effect of alterations in muscle coordination on running economy is largely unknown. Stretching, which is another mode of training, may induce acute neuromuscular effects but does not appear to alter running economy. There are also factors other than training structure that may influence running economy and neuromuscular adaptations. For example, passive interventions such as shoes and in-shoe orthoses, as well as the presence of musculoskeletal injury, may be considered important modulators of neuromuscular control and run performance. Alterations in muscle activity and running economy have been reported with different shoes and in-shoe orthoses; however, these changes appear to be subject-specific and non-systematic. Musculoskeletal injury has been associated with modifications in lower limb neuromuscular control, which may persist well after an athlete has returned to activity. The influence of changes in neuromuscular control as a result of injury on running economy has yet to be examined thoroughly, and should be considered in future experimental design and training analysis.

A protocol for measuring the direct effect of cycling on neuromuscular control of running in triathletes

The direct effects of cycling on movement and muscle recruitment patterns (neuromuscular control) during running are unknown but critical to success in triathlon. We outline and test a new protocol for investigating the direct influence of cycling on neuromuscular control during running. Leg movement (three-dimensional kinematics) and muscle recruitment (surface electromyography, EMG) were compared between a control run (no prior exercise) and a 30-min transition run that was preceded by 20 min of cycling. We conducted three experiments investigating: (a) the repeatability (between-day reliability) of the protocol; (b) the ability of the protocol to investigate, in highly trained national or international triathletes, the direct influence of cycling on neuromuscular control during running independent of neuromuscular fatigue; and (c) the ability of the protocol to provide a control, or baseline, measure of neuromuscular control (determined using a measure of stability) without causing fatigue. Kinematic and EMG measures of neuromuscular control during running showed moderate to high repeatability: mean coefficients of multiple correlation for repeatability of EMG and kinematics were 0.816 +/- 0.014 and 0.911 +/- 0.031, respectively. The protocol provided a robust baseline measure of neuromuscular control during running without causing neuromuscular fatigue (coefficients of multiple correlation for stability of EMG and kinematics were 0.827 +/- 0.023 and 0.862 +/- 0.054), while EMG and force data provided no evidence of fatigue. The protocol outlined here is repeatable and can be used to measure any direct influence of cycling on neuromuscular control during running.