Clinical presentation of exercise-associated hyponatremia in male and female IRONMAN® triathletes over three decades.

PURPOSE: Exercise-associated hyponatremia (EAH) is common in ultra-endurance events and severe cases are more common in females. The purpose of this paper is to compare the clinical presentation of EAH between male and female triathletes in ultra-endurance competitions. METHODS: Medical records with sodium concentrations (n = 3138) from the IRONMAN® World Championships over the timeframe of 1989-2019 were reviewed for both male (n = 2253) and female (n = 885) competitors. Logistic regression was used to explore the relationships between sex, sodium concentration, and various clinical presentations. RESULTS: When comparing male and female triathletes, clinical variables found to have a different relationship with sodium concentration include altered mental status (inversely related in males and not related in females), abdominal pain, muscle cramps, hypotension, and tachycardia (directly related in males and not related in females), and vomiting and hypokalemia (not related in males and inversely related in females). Overall, males lost significantly more weight than females, and notably, approximately half of all athletes were dehydrated and lost weight. CONCLUSIONS: Altered mental status, vomiting, abdominal pain, muscle cramps, hypotension, tachycardia, and hyperkalemia appear to present differently between sexes when comparing hyponatremic to eunatremic athletes. Although overhydration is the most common etiology of hypervolemic hyponatremia, hypovolemic hyponatremia comprises a significant amount of hyponatremic triathletes. Further understanding of how EAH presents helps athletes and medical professionals identify it early and prevent life-threatening complications.

Proper Disposal of Prescription Opioids in Southwest Virginia: Assessment of Patient, Physician, and Medical Student Beliefs and Practices.

CONTEXT: Southwestern Virginia demonstrates the highest regional mortality rate from prescription opioid overdoses. Nationally, 65% of patients misusing opioid medications received them from friends and family, underscoring the need for effective disposal of unused narcotics. OBJECTIVES: (1) To understand patient, provider, and medical student beliefs and misconceptions regarding proper methods of opioid disposal; (2) to characterize discrepancies that exist between patient self-reported habits and medical student/provider perceptions of opioid usage, disposal, and diversion. DESIGN: Descriptive, cross-sectional, observational study. SETTING: Large, nonprofit health care organization and allopathic medical school in Southwestern Virginia. PARTICIPANTS: All ambulatory patients 18 years or older presenting for elective consultation at health system orthopedics department; all institutionally employed physicians with active system e-mail addresses; and all current students at the associated medical school. MAIN OUTCOMES/MEASURES: Patients: The number who had received information regarding proper methods of opioid disposal, intended disposal method, methods of disposal considered appropriate, comfort level with opioid disposal, and demographic data. Physicians and Medical Students: The number who had received instruction regarding proper methods of opioid disposal, acceptable means of opioid disposal, most appropriate disposal method, disposal method most likely to be employed by patients, practice profile/prescribing data, and medical school year. RESULTS: In total, 64% of patients (n = 255/750) had never received instruction from a physician regarding opioid disposal; 56% of physicians (n = 212/732) and 78% (n = 80/171) of medical students indicated that they never received formal instruction regarding methods of disposal. The majority of physicians believed that their patients are most likely to use in-home methods of disposal or store prescription medications for future use; 61% of patients indicated a preference for accessible disposal facilities. CONCLUSIONS: The discrepancy between patient and physician responses highlights a lack of communication regarding disposal of unused opioid medications and is a target for future intervention.

Prediction of Autograft Hamstring Size for Anterior Cruciate Ligament Reconstruction Using MRI.

BACKGROUND: Hamstring autografts with a diameter of less than 8 mm for ACL reconstruction have an increased risk of failure, but there is no consensus regarding the best method to predict autograft size in ACL reconstruction. QUESTIONS/PURPOSES: (1) What is the relationship between hamstring cross-section on preoperative MRI and intraoperative autograft size? (2) What is the minimum hamstring tendon cross-sectional area on MRI needed to produce an autograft of at least 8 mm at its thickest point? METHODS: This was a retrospective cohort study of 68 patients. We collectively reviewed patients who underwent ACL reconstruction by three separate fellowship-trained surgeons at the Carilion Clinic between April 2010 and July 2013. We searched the patient records database of each surgeon using the keyword "ACL". A total of 293 ACL reconstructions were performed during that time period. Of those, 23% (68 patients) had their preoperative MRI (1.5 T or 3 T magnet) performed at the Carilion Clinic with MRI confirmation of acute total ACL rupture. Exclusion criteria included previous ACL reconstructions, multiligamentous injuries, and history of acute hamstring injuries.After applying the exclusion criteria, there were 29 patients in the 1.5 T magnet group and 39 in the 3 T group. Median age (range) was 29 years (12 to 50) for the 1.5 T group and 19 years (9 to 43) for the 3 T group. The patients were 41% female in the 1.5 T group and 23% female in the 3 T group. Use of 1.5 T or 3 T magnets was based on clinical availability and scheduling. The graft's preoperative cross-sectional area was compared with the intraoperative graft's diameter. The MRI measurements were performed by a single musculoskeletal radiologist at the widest point of the medial femoral condyle and at the joint line. Intraoperative measurements were performed by recording the smallest hole the graft could fit through at its widest point. Pearson's correlation coefficients were calculated to determine the relationship between graft size and tendon cross-sectional area. A simple logistic regression analysis was used to calculate the cutoff cross-sectional areas needed for a graft measuring at least 8 mm at its thickest point. Intrarater reliability was evaluated based on re-measurement of 19 tendons, which produced an overall intraclass correlation coefficient (ICC) of 0.96 95% (CI 0.93 to 0.98). A p value < 0.05 was considered significant. RESULTS: In general, the correlation between MRI-measured hamstring thickness and hamstring graft thickness as measured in the operating room were good but not excellent. The three measurements that demonstrated the strongest correlation with graft size in the 1.5 T group were the semitendinosus at the medial femoral condyle (r = 0.69; p < 0.001), the semitendinosus and gracilis at the medial femoral condyle (r = 0.70; p < 0.001), and the mean semitendinosus and gracilis (r = 0.64; p < 0.001). These three measurements had correlation values of 0.53, 0.56, and 0.56, respectively, in the 3 T MRI group (all p values < 0.001). To create an 8-mm hamstring autograft, the mean semitendinosus plus gracilis cutoff values areas were 18.8 mm and 17.5 mm for the 1.5 T and 3.0 T MRI groups, respectively. CONCLUSIONS: Imaging performed according to routine knee injury protocol can be used to preoperatively predict the size of hamstring autografts for ACL reconstructions. In clinical practice, this can assist orthopaedic surgeons in graft selection and surgical planning. LEVEL OF EVIDENCE: Level II, diagnostic study.

Use of Observation Status Versus Readmission in Elective Total Knee and Hip Arthroplasty Returns to Hospital: A Single-Institution Perspective.

BACKGROUND: The Affordable Care Act's Readmission Reduction Program (RRP) and ongoing transparency efforts to promote consumer-driven competition place significant institutional focus on improving 30-day readmission rates. It remains unclear whether the reduction in readmission rates subsequent to the RRP occurred due to improved quality and/or partly due to increased use of observation status in conditions that may have been classified as readmissions prior to the RRP. We hypothesize that a significant percentage of our institution's 30-day readmissions after elective total knee and hip arthroplasty (TKA/THA) overestimate the needs, duration, and complexity of the hospital-based intervention and inaccurately reflect the quality of service provided. METHODS: We performed a retrospective review of prospectively collected quality control data for 30-day returns to hospital after elective TKA/THA at our institution over a 2-year period. After stratification of the readmissions to under 48-hour and over 48-hour length of stay, we calculated the financial implications to our institution if the under 48-hour length of stay admissions were reclassified as an observation by applying discharge-weighted and payment-weighted analyses to the 2017 RRP report. We then calculated the out-of-pocket expenses for the under 48-hour Medicare subpopulation. RESULTS: We found that 16.7% of the 30-day readmissions after elective TKA/THA required a length of stay under 48 hours. If the short length of stay TKA/THA readmissions were reclassified as observations, our institution's 2018 RRP penalty would have been reduced to 39% or $334,512.28. However, this reclassification would result in an increase in out-of-pocket expenses by $540.25 (range $291.56-$1105.08) per patient. CONCLUSION: A subpopulation of 30-day readmissions does not require a level of care consistent with inpatient admission services. Classification of this short length of stay subpopulation as an observation vs an admission per Centers for Medicare and Medicaid Services guidelines would have removed our institution from the TKA/THA-specific RRP penalty. However, this would result in the unintended consequence of shifting costs, particularly self-administered drug costs, to patients.

Triathlon Medical Coverage: A Guide for Medical Directors.

Interest and participation in triathlon has grown rapidly over the past 20 yr and with this growth, there has been an increase in the number of new events. To maximize the safety of participation, triathlons require medical directors to plan and oversee medical care associated with event participation. Provision of proper medical care requires knowledge of staffing requirements, common triathlon medical conditions, impact of course design, communication skill, and a familiarity of administrative requirements. These guidelines serve as a tool for triathlon medical and race directors to improve race safety for athletes.

Medical Encounters and Treatment Outcomes in Ironman-Distance Triathlon.

PURPOSE: This study aimed to examine the injury and illness characteristics, treatments, and outcomes at elite ultraendurance triathlon events. METHODS: We quantified participant demographics, injury types, treatments, and disposition for medical encounters at 27 Ironman-distance triathlon championships from 1989 to 2019. We then calculated the likelihood of concurrent medical complaints in each encounter. RESULTS: We analyzed 10,533 medical encounters among 49,530 race participants for a cumulative incidence of 221.9/1000 participants (95% confidence interval [CI] = 217.7-226.2). Younger (<35 yr; 259.3/1000, 95% CI = 251.6-267.2) and older athletes (70+ yr; 254.0/1000, 95% CI = 217.8-294.4) presented to the medical tent at higher rates than middle-age adults (36-69 yr; 180.1/1000, 95% CI = 175.4-185.0). Female athletes also presented at higher rates when compared with males (243.9/1000, 95% CI = 234.9-253.2 vs 198.0/1000, 95% CI = 193.4-202.6). The most common complaints were dehydration (438.7/1000, 95% CI = 426.2-451.6) and nausea (400.4/1000, 95% CI = 388.4-412.6). Intravenous fluid was the most common treatment (483/1000; 95% CI = 469.8-496.4). Of the athletes who received medical care, 116.7/1000 (95% CI = 110.1-123.4) did not finish the race, and 17.1/1000 (95% CI = 14.7-19.8) required hospital transport. Athletes rarely presented with an isolated medical condition unless their injury was dermatologic or musculoskeletal in nature. CONCLUSIONS: Ultraendurance triathlon events have high rates of medical encounters among female athletes, as well as both younger and older age categories. Gastrointestinal and exertional-related symptoms are among the most common complaints. Intravenous infusions were the most common treatment after basic medical care. Most athletes entering the medical tent finished the race, and a small percentage were dispatched to the hospital. A more thorough understanding of common medical occurrences, including concurrent presentations and treatments, will allow for improved care and optimal race management.

Landing biomechanics deficits in anterior cruciate ligament reconstruction patients can be assessed in a non-laboratory setting.

Landing biomechanics provide important information pertaining to second anterior cruciate ligament (ACL) injury risk in patients following ACL reconstruction (ACLR). While traditional motion analysis technologies are often impractical for use in non-laboratory settings, methods to assess landing biomechanics which are inexpensive, portable, and user-friendly have recently been developed and validated. The purpose of this study was to compare landing kinematics and kinetics between ACLR patients and uninjured controls in a non-laboratory setting. Sixteen ACLR patients (7 male/9 female, 6-12 months post-ACLR) and 16 gender-matched controls completed seven bilateral drop vertical jumps and seven unilateral drop landings on each limb. Plantar force was measured bilaterally using force sensing insoles and frontal and sagittal-plane knee kinematics were measured using two tablets, six reflective markers, and automated point tracking software. Plantar force impulse normalized symmetry index (NSI) and knee frontal plane projection angle (FPPA) range of motion were computed during bilateral landing, and knee flexion range of motion NSI was computed during unilateral landing and compared between groups using independent samples t tests. ACLR patients had larger NSIs (reflecting less symmetry) for plantar force impulse during bilateral landing (p < 0.001) and knee flexion range of motion during unilateral landing (p = 0.004). No between-group differences were observed for knee FPPA range of motion (p = 0.111). This study is an important step towards assessing landing biomechanics in non-research settings with the goal of providing quantitative injury risk metrics in a clinical setting that can be used for return to sport decision making.

Reduction of risk factors for ACL Re-injuries using an innovative biofeedback approach: A phase I randomized clinical trial.

OBJECTIVES: Determine the safety and initial efficacy of a novel biofeedback intervention to improve landing mechanics in patients following anterior cruciate ligament reconstruction (ACLR). METHODS: Forty patients post-ACLR (age: 16.9 ± 2.0 years) were randomly allocated to a biofeedback intervention or an attention control group. Patients in the biofeedback group completed 12 sessions over six-weeks that included bilateral unweighted squats with visual and tactile biofeedback. Patients in the control group completed a six-week educational program. Lower extremity mechanics were collected during a bilateral stop jump at baseline, six-weeks, and 12-weeks post-intervention. Linear mixed-effects models adjusted for sex and graft type determined the main effects of and interactions between group and time. RESULTS: No group by time interaction existed for peak knee extension moment symmetry. A group by time interaction existed for peak vertical ground reaction force symmetry (p = 0.012), where patients in the biofeedback group had greater improvements in symmetry between baseline and post-intervention that were not maintained through the retention assessments. CONCLUSION: This novel biofeedback program did not reduce risk factors for second ACL injuries. Future work could develop and test multidisciplinary interventions for reducing second ACL injury risk factors. CLINICALTRIALS: GOV IDENTIFIER: (NCT03273673).

The impact of standardized footwear on load and load symmetry.

BACKGROUND: The inability to standardize footwear is a potential issue when measuring landing kinetics in non-laboratory settings. This study determined the impact of not standardizing footwear on load and load symmetry during landing. A secondary purpose of this study was to introduce the Load Analysis Program, an open-source MATLAB® user-interface for computing kinetic and kinetic symmetry from data collected using loadsol® sensors. METHODS: Forty uninjured participants completed bilateral and unilateral landing tasks in their own preferred athletic footwear and in laboratory-standardized footwear. Peak impact force, impulse, and a limb symmetry index of both kinetic outcomes were computed using loadsol® sensors (200 Hz) for both footwear conditions, and compared between footwear conditions using intraclass correlation coefficients and Bland-Altman plots. FINDINGS: The agreement between the preferred and standardized conditions was good to excellent for peak impact force, peak impact force limb symmetry index, and impulse limb symmetry index during the bilateral task (intraclass correlation coefficient = 0.870-0.951). The agreement was moderate to poor for unilateral limb symmetry index measures (intraclass correlation coefficient = 0.399-0.516). During the preferred footwear condition, impulse was greater for the left limb during bilateral landing, and peak impact force during unilateral landing on the right limb was decreased, when compared to the standardized footwear condition (p < 0.05). INTERPRETATION: These results suggest that while not standardizing footwear can alter the results of certain load metrics, laboratory-relevant landing mechanics information can be obtained with participants wearing their own footwear.

Reduction of Risk Factors for ACL Re-injuries using an Innovative Biofeedback Approach: Rationale and Design.

Nearly 1 in 60 adolescent athletes will suffer anterior cruciate ligament (ACL) injuries with 90% of these athletes electing to undergo an ACL reconstruction (ACLR) at an estimated annual cost of $3 billion. While ACLR and subsequent rehabilitation allow these athletes to return to sports, they have a 15-fold increased risk of second ACL injuries. The modification of post-operative rehabilitation to improve movement and loading symmetry using visual and tactile biofeedback could decrease the risk factors for sustaining a second ACL injury. Participants included 40 adolescent ACLR patients who were intending to return to full sport participation. This preliminary randomized controlled trial (RCT) examined the changes in knee extension moment symmetry, a known risk factor for second ACL injuries, during landing from a stop-jump task between the following time-points: pre-intervention, immediate post-intervention, and subsequent follow-up 6-weeks post-intervention. Participants met twice per week for six-weeks (12-session). The intervention included bilateral squat biofeedback (visual and tactile); the attention control group attended weekly educational sessions. This RCT enrolled and randomize 40 participants over a two-and-a-half-year period. All participants were greater than 4.5 months post-op from a primary, unilateral ACLR and were released to participate by their treating physician. The findings from this pilot biofeedback RCT will provide critical effect size estimates for use in subsequent larger clinical trials.

Physical Performance Improves With Time and a Functional Knee Brace in Athletes After ACL Reconstruction.

BACKGROUND: Athletes who return to sport (RTS) after anterior cruciate ligament reconstruction (ACLR) often have reduced physical performance and a high reinjury rate. Additionally, it is currently unclear how physical performance measures can change during the RTS transition and with the use of a functional knee brace. PURPOSE/HYPOTHESIS: The purpose of this study was to examine the effects of time since surgery (at RTS and 3 months after RTS) and of wearing a brace on physical performance in patients who have undergone ACLR. We hypothesized that physical performance measures would improve with time and would not be affected by brace condition. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 28 patients who underwent ACLR (9 males, 19 females) completed physical performance testing both after being released for RTS and 3 months later. Physical performance tests included the modified agility t test (MAT) and vertical jump height, which were completed with and without a knee brace. A repeated-measures analysis of variance determined the effect of time and bracing on performance measures. RESULTS: The impact of the knee brace was different at the 2 time points for the MAT side shuffle (P = .047). Wearing a functional knee brace did not affect any other physical performance measure. MAT times improved for total time (P < .001) and backpedal (P < .001), and vertical jump height increased (P = .002) in the 3 months after RTS. CONCLUSION: The present study showed that physical performance measures of agility and vertical jump height improved in the first 3 months after RTS. This study also showed that wearing a knee brace did not hinder physical performance. CLINICAL RELEVANCE: Wearing a functional knee brace does not affect physical performance, and therefore a brace could be worn during the RTS transition without concern. Additionally, physical performance measures may still improve 3 months past traditional RTS, therefore justifying delayed RTS.

Hop testing symmetry improves with time and while wearing a functional knee brace in anterior cruciate ligament reconstructed athletes.

BACKGROUND: There is currently no consensus among orthopaedic surgeons as to when patients with anterior cruciate ligament reconstruction are ready to return to sport or whether or not patients should wear a functional knee brace during athletic activity. The purpose of the present study was to determine the effects of time since return to sport and of a functional knee brace on hop distance and loading symmetry during hop testing in patients with anterior cruciate ligament reconstruction. METHODS: Twenty-eight patients with anterior cruciate ligament reconstruction completed hop testing after being released to return to sport and again 3 months later, both with and without wearing a custom fit extension constraint functional knee brace. The loadsol® captured plantar loading data (100 Hz) to quantify peak impact force, loading rate, and impulse during the final landing of every hop test. A limb symmetry index was calculated between surgical and non-surgical limbs for hop distance and loading measures. FINDINGS: Wearing a knee brace increased hop distance symmetry during the single and crossover hop tests and peak impact force symmetry on each test (all p < 0.05). While single (p = 0.022) and triple (p = 0.002) hop distance symmetry increased with time, there was no effect of time on any loading symmetry outcomes. INTERPRETATION: These results support using a functional knee brace during athletic activities for improving symmetry in the early return to sport period. These results also support previous findings that while hop distance symmetry improves with time, asymmetrical landing mechanics do not and should be addressed clinically.

Associations between Distance and Loading Symmetry during Return to Sport Hop Testing.

PURPOSE: Hop tests are widely used to quantify recovery from anterior cruciate ligament reconstruction (ACLR) surgery. However, there is evidence that simply measuring hop distance may not be indicative of the quality of movement or representative of potential limitations in hopping mechanics, particularly during landing. The first purpose of the present study was to compare hop distance and loading symmetry between ACLR athletes and healthy uninjured recreational athletes. The second was to determine the association between hop distance and loading symmetry. METHODS: Twenty-five ACLR patients and 30 healthy controls completed the single hop, triple hop, and crossover hop test on each limb while the loadsol®, a single-sensor force insole, collected impact forces (100 Hz). A limb symmetry index (LSI) was calculated for hop distance, peak impact force, loading rate, and impulse from the final landing of each trial. LSI values were compared between groups using Mann-Whitney U tests, and distance and loading LSI values were compared using Spearman rank correlations. RESULTS: ACLR patients had reduced symmetry in hop distance and loading relative to healthy controls for every hop test and outcome measure (P < 0.05), except peak impact force on the single hop. Hop distance symmetry was significantly related to each loading symmetry measure on the crossover hop test (P < 0.01) and to peak impact force and impulse symmetry on the single hop test (P < 0.05) in each group. CONCLUSION: This study demonstrates that ACLR patients both hop further and generate larger forces when hopping on their nonsurgical limb relative to their surgical limb. In addition, hop distance and loading symmetry provide clinicians and researchers with different information and therefore should be considered together when making return to sport decisions.

The Role of an Extra-Articular Tenodesis in Revision of Anterior Cruciate Ligament Reconstruction.

Patients who present for anterior cruciate ligament (ACL) revision with a high-grade pivot shift at the time of an index ACL revision procedure and subsequent reconstruction failure or a high-grade pivot shift at revision surgery, patients with generalized joint laxity, and those requiring softs tissue grafts should be considered candidates for lateral tenodesis to supplement intraarticular graft revision. Although there is no consensus regarding the optimal lateral tenodesis technique, due to the tibial positioning associated with tensioning and fixation of extra-articular procedures, a lateral tenodesis should not be used in patients with posterolateral corner injuries or lateral compartment articular disease.

Limb asymmetry during recovery from anterior cruciate ligament reconstruction.

There is limited literature that follows a population of Anterior Cruciate Ligament Reconstruction (ACLR) patients through recovery. Our aim was to examine differences in movement and loading patterns across time and between limbs over four visits during 12 months post-ACLR. We hypothesized that kinematic and kinetic data during a stop-jump would have time- and limb-dependent differences through 12 months post-surgery. Twenty-three ACLR athletes performed five vertical stop-jumps at 4, 5, 6, and 12 months post-op with motion capture and force plate data collection. The peak knee flexion (PKF) was different between the 4 and 12, 5 and 6, and the 5 and 12 month visits with earlier months exhibiting higher PKF. The peak vertical ground reaction force (vGRF) was lower at 4 than at 5 and 6 months. The peak posterior ground reaction force (pGRF) was lower at 4 months than all other visits. Frontal knee and sagittal hip range of motion (ROM) were different between 12 months and each previous visit. Asymmetries were present in peak vGRF, peak knee extension moment and impulse up to 12 months. The loading rate and peak pGRF demonstrated between limb differences up to 6 months; limb stiffness demonstrated differences up to 5 months post-ACLR. PKF was only asymmetric at the 4 month visit. While some variables improved in the 12 months post-ACLR, limb asymmetries in peak knee extension moment, peak vGRF and impulse persisted up to 12 months. Additionally, frontal plane knee and sagittal hip ROM had not normalized at 12 months. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1887-1893, 2018.

Medical considerations in triathlon competition: recommendations for triathlon organisers, competitors and coaches.

Competitors in triathlons experience a range of environmental conditions and physiological demands in excess of that found in individual sport events of comparable duration. Consequently, there is a broad range of possible medical problems and complications that must be taken into account when preparing for such races. For most competitors, an Olympic-distance triathlon typically takes between 2-4 hours to complete. This race begins with a swimming segment of 1500 m. Given the wide variety of race venues found around the world, these swims occur in an assortment of water temperatures (from warm to cold) and conditions (from ocean surf to lake calm). Swimmers often exit the water in a state of moderate dehydration and hypothermia and then immediately start the 40 km cycling leg. Many do so in their swimming attire. A wide variety of road surfaces, technically challenging topography, variable environmental conditions and dramatically changing velocities can be encountered on the cycle course. The race concludes with a 10 km running leg. Since it is the final leg, it is often completed in higher ambient temperatures than those encountered at the start, with the athlete possibly running in a significant state of dehydration and fatigue. Other medical problems commonly encountered in triathlon include: muscle cramping, heat illness, postural hypotension, excessive exposure to ultraviolet radiation, musculoskeletal injuries and trauma, gastrointestinal problems as well as post-race bacterial infection, immunosuppression, sympathetic nervous system and psychological exhaustion, and haemolysis. The rate of occurrence of such events and the severity of their potentially negative outcomes is a function of the methods used by both the race organisers and the competitors to prevent or respond to the conditions imposed by the race. Triathletes also commonly compete in both shorter 'sprint distance' events (in the range of a 0.75 km swim, 20 km cycle and 5 km run) and longer events including both one-half and full Ironman distances (2.5 and 3.8 km swim, 80 and 180 km cycle, 20 and 42 km run, respectively), as well as ultra-distance events that exceed the Ironman distance. In the longer events, the previously mentioned medical considerations are further magnified and additional considerations such as hyponatraemia can also occur. Reducing risk associated with these concerns is accomplished by: taking into account weather and water temperature/conditions data prior to event scheduling; effective swim, cycle and run course organisation and management; environmental monitoring prior to and during the event; the implementation of a water safety plan; provision of appropriate fluid replacement throughout the course; implementation of helmet use and non-drafting regulations in the cycling leg; and competitor knowledge regarding fluid replacement, biomechanical technique, physical preparation, safe equipment and course familiarity. Despite these concerns, triathlon participation appears to relatively safe for persons of all ages, assuming that high-risk adults undertake health screening.