Risk Factors for Running-Related Injury in High School and Collegiate Cross-country Runners: A Systematic Review.

OBJECTIVE: To summarize and describe risk factors for running-related injuries (RRIs) among high school and collegiate cross-country runners. DESIGN: Descriptive systematic review. LITERATURE SEARCH: Four databases (Scopus, SPORTDiscus, CINAHL, Cochrane) were searched from inception to August 2023. STUDY SELECTION CRITERIA: Studies assessing RRI risk factors in high school or collegiate runners using a prospective design with at least 1 season of follow-up were included. DATA SYNTHESIS: Results across each study for a given risk factor were summarized and described. The NOS and GRADE frameworks were used to evaluate quality of each study and certainty of evidence for each risk factor. RESULTS: Twenty-four studies were included. Overall, study quality and certainty of evidence were low to moderate. Females or runners with prior RRI or increased RED-S (relative energy deficiency in sport) risk factors were most at risk for RRI, as were runners with a quadriceps angle of >20° and lower step rates. Runners with weaker thigh muscle groups had increased risk of anterior knee pain. Certainty of evidence regarding training, sleep, and specialization was low, but suggests that changes in training volume, poorer sleep, and increased specialization may increase RRI risk. CONCLUSION: The strongest predictors of RRI in high school and collegiate cross-country runners were sex and RRI history, which are nonmodifiable. There was moderate certainty that increased RED-S risk factors increased RRI risk, particularly bone stress injuries. There was limited evidence that changes in training and sleep quality influenced RRI risk, but these are modifiable factors that should be studied further in this population. J Orthop Sports Phys Ther 2024;54(2):1-13. Epub 16 November 2023. doi:10.2519/jospt.2023.11550.

Running-related injuries in middle school cross-country runners: Prevalence and characteristics of common injuries.

BACKGROUND: Understanding the prevalence and factors associated with running-related injuries in middle school runners may guide injury prevention. OBJECTIVE: To determine the prevalence of running-related injuries and describe factors related to a history of injury. DESIGN: Retrospective cross-sectional study. SETTING: Survey distributed online to middle school runners. METHODS: Participants completed a web-based survey regarding prior running-related injuries, training, sleep, diet, and sport participation. MAIN OUTCOME MEASUREMENTS: Prevalence and characteristics differentiating girls and boys with and without running-related injury history adjusted for age. PARTICIPANTS: Youth runners (total: 2113, average age, 13.2 years; boys: n = 1255, girls: n = 858). RESULTS: Running-related injuries were more prevalent in girls (56% vs. 50%, p = .01). Ankle sprain was the most common injury (girls: 22.5%, boys: 21.6%), followed by patellofemoral pain (20.4% vs. 7.8%) and shin splints (13.6% vs. 5.9%); both were more prevalent in girls (p < .001). Boys more frequently reported plantar fasciitis (5.6% vs. 3.3%, p = .01), iliotibial band syndrome (4.1% vs. 1.4%, p = .001) and Osgood-Schlatter disease (3.8% vs. 1.2%, p = .001). Runners with history of running-related injuries were older, ran greater average weekly mileage, ran faster, had fewer average hours of sleep on weekends, skipped more meals, missed breakfast, and consumed less milk (all p < .05). Girls with history of running-related injuries reported higher dietary restraint scores, later age of menarche, more menstrual cycle disturbances, and higher likelihood of following vegetarian diets and an eating disorder diagnosis (all p < .05). Runners with no history of running-related injuries were more likely to have participated in ≥2 years of soccer or basketball (p < .001). CONCLUSIONS: Most middle school runners reported a history of running-related injuries and certain injuries differing by gender. Modifiable factors with the greatest association with running-related injuries included training volume, dietary restraint, skipping meals, and less sleep. Sport sampling, including participation in ball sports, may reduce running-related injury risk in this population.

Prevalence and factors associated with bone stress injury in middle school runners.

BACKGROUND: Bone stress injury (BSI) in youth runners is clinically important during times of skeletal growth and is not well studied. OBJECTIVE: To evaluate the prevalence, anatomical distribution, and factors associated with running-related BSI in boy and girl middle school runners. DESIGN: Retrospective cross-sectional study. SETTING: Online survey distributed to middle school runners. METHODS: Survey evaluated BSI history, age, grade, height, weight, eating behaviors, menstrual function, exercise training, and other health characteristics. MAIN OUTCOME MEASUREMENTS: Prevalence and characteristics associated with history of BSI, stratified by cortical-rich (eg, tibia) and trabecular-rich (pelvis and femoral neck) locations. PARTICIPANTS: 2107 runners (n = 1250 boys, n = 857 girls), age 13.2 ± 0.9 years. RESULTS: One hundred five (4.7%) runners reported a history of 132 BSIs, with higher prevalence in girls than boys (6.7% vs 3.8%, p = .004). The most common location was the tibia (n = 51). Most trabecular-rich BSIs (n = 16, 94% total) were sustained by girls (pelvis: n = 6; femoral neck: n = 6; sacrum: n = 4). In girls, consuming <3 daily meals (odds ratio [OR] = 18.5, 95% confidence interval [CI] = 7.3, 47.4), eating disorder (9.8, 95% CI = 2.0, 47.0), family history of osteoporosis (OR = 6.9, 95% CI = 2.6, 18.0), and age (OR = 1.6, 95% CI = 1.0, 2.6) were associated with BSI. In boys, family history of osteoporosis (OR = 3.2, 95% CI = 1.2, 8.4), prior non-BSI fracture (OR = 3.2, 95% CI = 1.6, 6.7), and running mileage (OR = 1.1, 95% CI = 1.0, 1.1) were associated with BSI. Participating in soccer or basketball ≥2 years was associated with lower odds of BSI for both sexes. CONCLUSION: Whereas family history of osteoporosis and prior fracture (non-BSI) were most strongly related to BSI in the youth runners, behaviors contributing to an energy deficit, such as eating disorder and consuming <3 meals daily, also emerged as independent factors associated with BSI. Although cross-sectional design limits determining causality, our findings suggest promoting optimal skeletal health through nutrition and participation in other sports including soccer and basketball may address factors associated with BSI in this population.

Adolescent Running Biomechanics - Implications for Injury Prevention and Rehabilitation.

Global participation in running continues to increase, especially amongst adolescents. Consequently, the number of running-related injuries (RRI) in adolescents is rising. Emerging evidence now suggests that overuse type injuries involving growing bone (e.g., bone stress injuries) and soft tissues (e.g., tendinopathies) predominate in adolescents that participate in running-related sports. Associations between running biomechanics and overuse injuries have been widely studied in adults, however, relatively little research has comparatively targeted running biomechanics in adolescents. Moreover, available literature on injury prevention and rehabilitation for adolescent runners is limited, and there is a tendency to generalize adult literature to adolescent populations despite pertinent considerations regarding growth-related changes unique to these athletes. This perspective article provides commentary and expert opinion surrounding the state of knowledge and future directions for research in adolescent running biomechanics, injury prevention and supplemental training.

Musculoskeletal Injuries in Ultra-Endurance Running: A Scoping Review.

Ultra-endurance running (UER) has seen an important increase in participation over the last few decades. Long hours of UER can lead to excessive stress on the body, resulting in musculoskeletal injuries (MSKI). UER is not a uniform sport and events can differ considerably in distance (over 42.195 km), time (e.g., events over 6 h) and multi-day or multi-stage events on various surfaces (e.g., track, on-road, off-road). The aims of this scoping review were therefore: (1) to examine the current evidence of MSKI, providing a synthesis of the most common MSKI by anatomical region and specific diagnosis; (2) categorize MSKI by type of UER activity (competition: time-limited; multi-stage; continuous UER events and training); (3) describe knowledge gaps in the literature and provide advice on potential further research. Our electronic literature search (PubMed, SPORTDiscus, Web of Science) identified a total of 13 studies (9 in competition, and 4 in training). Anatomical site, diagnosis and rate of injuries differ between competition and training as well as between different UER types. MSKI are observed in 18% of multi-stage events (0.7-1.8 injuries/runner and 7.2 injuries/1000 h). Most MSKI involve the lower leg (35.0%), ankle (16.8%), knee (13.1%) and foot (12.6%), with main diagnosis of medial tibial stress syndrome (30.1%) and patella femoral pain syndrome (PFPS; 7.2%). Single, continuous UER events differ between a 1005 km road race with almost all of the injuries due to overuse, with the main anatomical site of the knee (31%), ankle (28%) and lower leg (14%) and main diagnosis of PFPS (15.6%), compared to a 65 km trail race, with 32.8% of MSKI, mainly on the foot [plantar fasciitis (28.6%)], ankle [sprain (28.6%)] and knee. Timed-UER events (injury rate of 2.1 injuries/athlete) observed most injuries on the ankle (36%) and knee (19%), with the main diagnosis of tendinitis of the foot dorsiflexors (30%). Injuries during training most commonly affect, the back (42%), and knee (40%) and bone stress injuries (22%). Main diagnoses include ankle sprain (18%), iliotibial band injury (16%) and Achilles tendinopathy (11%). Future considerations include examining MSKI in different UER events, environments and surfaces, and on larger study populations. Establishing risk factors, examining sex differences and using a standard reporting system of MSKI in UER are also important.

Effect of Sodium Supplements and Climate on Dysnatremia During Ultramarathon Running.

OBJECTIVE: Analyze the effect of sodium supplementation, hydration, and climate on dysnatremia in ultramarathon runners. DESIGN: Prospective observational study. SETTING: The 2017 80 km (50 mile) stage of the 250 km (150 mile) 6-stage RacingThePlanet ultramarathon in 2017 Chilean, Patagonian, and 2018 Namibian, Mongolian, and Chilean deserts. PARTICIPANTS: All race entrants who could understand English were invited to participate, with 266 runners enrolled, mean age of 43 years (± 9), 61 (36%) females, average weight 74 kg (± 12.5), and average race time 14.5 (± 4.1) hours. Post-race sodium collected on 174 (74%) and 164 (62%) participants with both the blood sample and post-race questionnaire. INTERVENTION: Weight change and finish line serum sodium levels were gathered. MAIN OUTCOME MEASURES: Incidence of exercise-associated hyponatremia (EAH; <135 mmol·L-1) and hypernatremia (>145 mmol·L-1) by sodium ingestion and climate. RESULTS: Eleven (6.3%) runners developed EAH, and 30 (17.2%) developed hypernatremia. Those with EAH were 14 kg heavier at baseline, had significantly less training distances, and averaged 5 to 6 hours longer to cover 50 miles (80 km) than the other participants. Neither rate nor total ingested supplemental sodium was correlated with dysnatremia, without significant differences in drinking behaviors or type of supplement compared with normonatremic runners. Hypernatremic runners were more often dehydrated [8 (28%), -4.7 kg (± 9.8)] than EAH [4 (14%), -1.1 kg (± 3.8)] (P < 0.01), and EAH runners were more frequently overhydrated (6, 67%) than hypernatremia (1, 11%) (P < 0.01). In the 98 (56%) runners from hot races, there was EAH OR = 3.5 [95% confidence interval (CI), 0.9-25.9] and hypernatremia OR = 8.8 (95% CI, 2.9-39.5) compared with cold races. CONCLUSIONS: This was the first study to show that hot race climates are an independent risk factor for EAH and hypernatremia. Sodium supplementation did not prevent EAH nor cause hypernatremia. Longer training distances, lower body mass, and avoidance of overhydration were shown to be the most important factors to prevent EAH and avoidance of dehydration to prevent hypernatremia.

Youth running consensus statement: minimising risk of injury and illness in youth runners.

Despite the worldwide popularity of running as a sport for children, relatively little is known about its impact on injury and illness. Available studies have focused on adolescent athletes, but these findings may not be applicable to preadolescent and pubescent athletes. To date, there are no evidence or consensus-based guidelines identifying risk factors for injury and illness in youth runners, and current recommendations regarding suitable running distances for youth runners at different ages are opinion based. The International Committee Consensus Work Group convened to evaluate the current science, identify knowledge gaps, categorise risk factors for injury/illness and provide recommendations regarding training, nutrition and participation for youth runners.

Pain Is Inevitable But Suffering Is Optional: Relationship of Pain Coping Strategies to Performance in Multistage Ultramarathon Runners.

INTRODUCTION: Ultramarathon runners commonly endure musculoskeletal pain during endurance events. However, the effect of pain coping skills on performance has not been examined. METHODS: A prospective observational study during three 250 km (155 mi), 6 stage ultramarathons was conducted. Finish line surveys were completed after each of the four 40 km (25 mi) and one 80 km (50 mi) stages of racing. Variables gathered included pain intensity, pain coping strategy use, pain interference, finishing position (quintile), and successful race completion. RESULTS: A total of 204 participants (age 41.4±10.3 y; 73% male) reported average pain intensity of 3.9 (±2.0 SD) and worst pain intensity of 5.3 (±2.3) on a 0 to 10 scale. They used greater adaptive pain coping strategies (3.0±1.3) relative to maladaptive strategies (1.3±1.1). Worst pain and pain interference increased over each stage of the race for all runners (P<0.001), with worst pain being significantly different by finishing status (P=0.02). Although all runners endured increased pain and interference, the nonfinishers (28 [14%]) had significantly greater differences in changes in pain intensity (P<0.01) and pain interference (P<0.001). Maladaptive pain coping strategies were more common in nonfinishers; with each 1-point increase (0-6 scale), there was a 3 times increase in odds of not finishing the race. CONCLUSIONS: Although increased pain intensity and pain interference was found in all multistage ultramarathon runners, successful event completion was significantly associated with less maladaptive pain coping. Training in coping with pain may be a beneficial part of ultramarathon preparation.

Accuracy of Estimated Creatinine in Multistage Ultramarathon Runners.

INTRODUCTION: Ultramarathon running is increasing in popularity worldwide, as is the growing body of research on these athletes. Multiple studies have examined acute kidney injury through estimated baseline creatinine (Cr) and glomerular filtration rate (GFR). Values are estimated through an age-based formula of GFR and the modification of diet in renal disease (MDRD) equation. However, the accuracy of this practice in a cohort of healthy athletes is unknown. METHODS: A prospective analysis of the first 40-km (25-mi) stage of 6-stage 250-km (155-mi) multistage ultramarathons in the Sahara, Namibia, Atacama, and Gobi Deserts. Runners had prerace measured baseline Cr compared to estimated values through age-based estimated GFR and back calculation of Cr through the MDRD equation. RESULTS: Forty-eight participants (27% female, age 39±10 y) had Cr values analyzed. The mean measured Cr was 0.99±0.17, which was 11% higher than an estimated Cr of 0.88±0.14 (P<0.01). Estimated age-based GFR was 95.9±5.8 mL⋅min-1 compared to GFR based on measured Cr and MDRD of 86.1±14.6 (P<0.001). CONCLUSIONS: Estimated values of GFR and Cr by standard age-based values and MDRD equation were significantly inaccurate, which would overinflate the incidence of acute kidney injury. Future studies should devise a new model for estimation of baseline Cr that is validated in this population.

Youth Distance Running: Strategies for Training and Injury Reduction.

Running is a popular sport for children in the United States. However, review of available literature on health effects and safety recommendations for youth running has not been previously conducted. Unique factors for injury include periods of growth during puberty and potential for growth plate injury. Youth runners may benefit from activities that incorporate high-impact loading and multidirectional movement for optimal bone maturation, exercises to strengthen tendons and muscles, and strategies aimed at improving running biomechanics to reduce risk of injury. In addition, addressing lifestyle factors, including nutrition and sleep is essential for a runner's general health. Similar to other sports, sports specialization should not be encouraged in youth runners. Reducing running-related injury in growing children and assessing readiness for running should be based on a combination of physical, emotional, psychological, social, and cognitive factors. Youth runners require individualized training and competition to safely participate in the sport.

How variability in pain and pain coping relate to pain interference during multistage ultramarathons.

An important and substantial body of literature has established that maladaptive and adaptive coping strategies significantly impact pain-related outcomes. This literature, however, is based primarily on populations with painful injuries and illnesses. Little is known about coping in individuals who experience pain in other contexts and whether coping impacts outcomes in the same way. In an effort to better understand pain coping in such contexts, this study evaluated pain coping in ultramarathon runners, a population known to experience moderate levels of pain with minimal perceived negative effects. This study reports on pain coping in 204 entrants in 2016 RacingThePlanet multistage ultramarathon events. Participants provided data over 5 consecutive days on pain severity, pain interference, exertion, and coping. Results demonstrated that the study participants were more likely to use adaptive than maladaptive coping responses. However, maladaptive coping, but not adaptive coping, was positively associated with percent time spent thinking about pain and pain-related interference. Taken together, the study supports the idea that this high functioning group of individuals experiencing pain emphasizes the use of adaptive coping strategies over maladaptive strategies, reinforcing the perspective that such a pattern may be the most effective way to cope with pain. Within the group, however, results supported traditional patterns, such that greater use of maladaptive strategies was associated with greater pain-related interference, suggesting that optimizing pain coping may be critical to reducing factors that may interfere with ultramarathon performance.

Exercise-Associated Hyponatremia, Hypernatremia, and Hydration Status in Multistage Ultramarathons.

OBJECTIVE: Dysnatremia and altered hydration status are potentially serious conditions that have not been well studied in multistage ultramarathons. The purpose of this study was to assess the incidence and prevalence of exercise-associated hyponatremia (EAH) (Na+ <135 mmol·L-1) and hypernatremia (Na+ >145 mmol·L-1) and hydration status during a multistage ultramarathon. METHODS: This study involved a prospective observational cohort study of runners competing in a 250-km (155-mile) multistage ultramarathon (in the Jordan, Atacama, or Gobi Desert). Prerace body weight and poststage (stage [S] 1 [42 km], S3 [126 km], and S5 [250 km]) body weight and serum sodium concentration levels were obtained from 128 runners. RESULTS: The prevalence of EAH per stage was 1.6% (S1), 4.8% (S3), and 10.1% (S5) with a cumulative incidence of 14.8%. Per-stage prevalence of hypernatremia was 35.2% (S1), 20.2% (S3), and 19.3% (S5) with a cumulative incidence of 52.3%. Runners became more dehydrated (weight change <-3%) throughout the race (S1=22.1%; S3=51.2%; S5=53.5%). Body weight gain correlated with EAH (r=-0.21, P = .02). Nonfinishers of S3 were significantly more likely to have EAH compared with finishers (75% vs 5%, P = .001), but there was no difference in either EAH or hypernatremia between nonfinishers and finishers of S5. CONCLUSIONS: The incidence of EAH in multistage ultramarathons was similar to marathons and single-stage ultramarathons, but the cumulative incidence of hypernatremia was 3 times greater than that of EAH. EAH was associated with increased weight gain (overhydration) in early stage nonfinishers and postrace finishers.

Ibuprofen versus placebo effect on acute kidney injury in ultramarathons: a randomised controlled trial.

BACKGROUND: Despite concerns that non-steroidal anti-inflammatory drugs (NSAIDs) contribute to acute kidney injury (AKI), up to 75% of ultramarathon runners ingest these during competition. The effect of NSAID on AKI incidence in ultramarathon runners is unclear. METHODS: Multisite randomised double-blind placebo-controlled trial in the Gobi, Atacama, Ecuador and Sri Lankan deserts to determine whether ibuprofen (400 mg every 4 hours) would be non-inferior to placebo during a 50-mile (80 km) foot race. The primary outcome was incidence of AKI defined as severity categories of 'risk' of injury of 1.5× baseline creatinine (Cr) or 'injury' as 2× Cr, combined to calculate total incidence at the finish line. Non-inferiority margin for difference in AKI rates was defined as 15%. RESULTS: Eighty-nine participants (47% ibuprofen and 53% placebo) were enrolled with similar demographics between groups. The overall incidence of AKI was 44%. Intent-to-treat analysis found 22 (52%) ibuprofen versus 16 (34%) placebo users developed AKI (18% difference, 95% CI -4% to 41%; OR 2.1, 95% CI 0.9 to 5.1) with a number needed to harm of 5.5. Greater severity of AKI was seen with ibuprofen compared with placebo (risk=38% vs 26%; 95% CI -9% to 34%; injury=14% vs 9%; 95% CI -10% to 21%). Slower finishers were less likely to encounter AKI (OR 0.67, 95% CI 0.47 to 0.98) and greater weight loss (-1.3%) increased AKI (OR 1.24, 95% CI 1.00 to 1.63). CONCLUSION: There were increased rates of AKI in those who took ibuprofen, and although not statistically inferior to placebo by a small margin, there was a number needed to harm of 5.5 people to cause 1 case of AKI. Consideration should therefore be taken before ingesting NSAID during endurance running as it could exacerbate renal injury. TRIAL REGISTRATION NUMBER: NCT02272725.

Paper Tape Prevents Foot Blisters: A Randomized Prevention Trial Assessing Paper Tape in Endurance Distances II (Pre-TAPED II).

OBJECTIVE: To determine whether paper tape prevents foot blisters in multistage ultramarathon runners. DESIGN: Multisite prospective randomized trial. SETTING: The 2014 250-km (155-mile) 6-stage RacingThePlanet ultramarathons in Jordan, Gobi, Madagascar, and Atacama Deserts. PARTICIPANTS: One hundred twenty-eight participants were enrolled: 19 (15%) from the Jordan, 35 (27%) from Gobi, 21 (16%) from Madagascar, and 53 (41%) from the Atacama Desert. The mean age was 39.3 years (22-63) and body mass index was 24.2 kg/m (17.4-35.1), with 31 (22.5%) females. INTERVENTIONS: Paper tape was applied to a randomly selected foot before the race, either to participants' blister-prone areas or randomly selected location if there was no blister history, with untaped areas of the same foot used as the control. MAIN OUTCOME MEASURES: Development of a blister anywhere on the study foot. RESULTS: One hundred six (83%) participants developed 117 blisters, with treatment success in 98 (77%) runners. Paper tape reduced blisters by 40% (P < 0.01, 95% confidence interval, 28-52) with a number needed to treat of 1.31. Most of the study participants had 1 blister (78%), with most common locations on the toes (n = 58, 50%) and heel (n = 27, 23%), with 94 (80%) blisters occurring by the end of stage 2. Treatment success was associated with earlier stages [odds ratio (OR), 74.9, P < 0.01] and time spent running (OR, 0.66, P = 0.01). CONCLUSION: Paper tape was found to prevent both the incidence and frequency of foot blisters in runners.

Exercise-Associated Collapse: Is Hyponatremia in Our Head?

Exercise-associated hyponatremia (EAH) is one of the most common causes of exercise-associated collapse. The primary pathogenesis of EAH is largely the result of excessive fluid intake but is influenced by other factors, including hormonal abnormalities (ie, inappropriate arginine vasopressin secretion), renal abnormalities, and mobilization of sodium stores. Early recognition of EAH is crucial to appropriate treatment, because symptoms are varied and may be confused with other causes of exercise-associated collapse. Onsite testing of [Na+] will confirm the diagnosis but is not always available. Rapid treatment of EAH will depend upon the type and severity of symptoms. Treatment protocols range from fluid restriction or oral hypertonic fluids for mild symptoms to intravenous hypertonic fluids for more severe symptoms. Preventative strategies should emphasize fluid consumption based on thirst and athlete/coach/staff education regarding proper hydration practices.

Incidence and Prevalence of Acute Kidney Injury During Multistage Ultramarathons.

OBJECTIVE: Determine prevalence, incidence, and risk factors of acute kidney injury (AKI) during multistage ultramarathons. DESIGN: Prospective observational cohort study. SETTING: Jordanian Desert 2012; Atacama Desert, Chile 2012 and 2013; and Gobi Desert 2013 RacingThePlanet 250 km, 6-stage, ultramarathons. PARTICIPANTS: One hundred twenty-eight participants (384 measurements) from the Jordan (25, 19.5%), Gobi (35, 27.3%), 2012 Atacama (24, 18.8%), and 2013 Atacama (44, 34.4%) races. INTERVENTIONS: Blood samples and weights were gathered and analyzed immediately after stage 1 (40 km), 3 (120 km), and 5 (225 km). MAIN OUTCOME MEASURES: Changes in serum creatinine (Cr), cumulative incidence, and prevalence of AKI were calculated for each stage with "risk of injury" defined as 1.5 × baseline Cr and "injury" defined as 2 × Cr. RESULTS: Cumulative incidence of AKI was 41.4%. Stage 1 had 56 (43.8%) with risk of AKI and 24 (18.8%) with injury; in stage 3, 61 (47.7%) were at risk, 41 (32%) had injury; in stage 5, 62 (48.4%) runners were at risk and 36 (28.1%) had injury. Acute kidney injury was significantly associated with females [odds ratio (OR), 4.64; 95% confidence interval (CI), 2.07-10.37; P < 0.001], lower pack weight (OR, 0.71; 95% CI, 0.56-0.91; P < 0.007), and percentage weight loss (OR, 0.87; 95% CI, 0.78-0.97; P < 0.015). Lowest quintile of finishers was less likely to develop AKI (OR, 0.18; 95% CI, 0.04-0.78; P < 0.022). CONCLUSIONS: Prevalence of AKI was 63%-78% during multistage ultramarathons. Female sex, lower pack weight, and greater weight loss were associated with renal impairment.

Running Injuries During Adolescence and Childhood.

The popularity of running among young athletes has significantly increased over the past few decades. As the number of children who participate in running increases, so do the potential number of injuries to this group. Proper care of these athletes includes a thorough understanding of the unique physiology of the skeletally immature athlete and common injuries in this age group. Treatment should focus on athlete education, modification of training schedule, and correction of biomechanical deficits contributing to injury. Early identification and correction of these factors will allow a safe return to running sports.

Medical Care for Swimmers.

Swimming is one of the most popular sports worldwide. Competitive swimming is one of the most watched sports during the Olympic Games. Swimming has unique medical challenges as a result of a variety of environmental and chemical exposures. Musculoskeletal overuse injuries, overtraining, respiratory problems, and dermatologic conditions are among the most common problems swimmers encounter. Although not unique to swimming, overtraining is a serious condition which can have significant negative impact on swimmers' health and performance. This review article is an attempt to discuss various issues that a medical team should consider when caring for swimmers.

A prospective randomized blister prevention trial assessing paper tape in endurance distances (Pre-TAPED).

OBJECTIVE: Friction foot blisters are a common injury occurring in up to 39% of marathoners, the most common injury in adventure racing, and represent more than 70% of medical visits in multi-stage ultramarathons. The goal of the study was to determine whether paper tape could prevent foot blisters in ultramarathon runners. METHODS: This prospective randomized trial was undertaken during RacingThePlanet 155-mile (250-km), 7-day self-supported ultramarathons in China, Australia, Egypt, Chile, and Nepal in 2010 and 2011. Paper tape was applied prerace to one randomly selected foot, with the untreated foot acting as the own control. The study end point was development of a hot spot or blister on any location of either foot. RESULTS: One hundred thirty-six participants were enrolled with 90 (66%) having completed data for analysis. There were 36% women, with a mean age of 40 ± 9.4 years (range, 25-40 years) and pack weight of 11 ± 1.8 kg (range, 8-16 kg). All participants developed blisters, with 89% occurring by day 2 and 59% located on the toes. No protective effect was observed by the intervention (47 versus 35; 52% versus 39%; P = .22), with fewer blisters occurring around the tape on the experimental foot than under the tape (23 vs 31; 25.6% versus 34.4%), yet 84% of study participants when queried would choose paper tape for blister prevention in the future. CONCLUSIONS: Although paper tape was not found to be significantly protective against blisters, the intervention was well tolerated with high user satisfaction.

Anterior cruciate ligament injury: mechanisms of injury and strategies for injury prevention.

Anterior cruciate ligament (ACL) injury is a common sports injury which can have severe negative consequences. Neuromuscular factors that increase risk, such as knee landing kinematics, may be ameliorated through training. Effective ACL injury prevention programs exist, although the ideal program is yet to be determined. It is recommended that athletes engaged in high-risk sports participate in an ACL injury prevention program to reduce the risk of sustaining this injury.