Schedule for Medicine of Cycling Conference 2016

Posted on May 17, 2016 by Courtney Barnes

We are excited to share with you our most updated schedule for MOCC 2016. We're busy finalizing details and hope you are making plans to join us in August!

Here is our current schedule:

SATURDAY, August 13, 2016 – Medicine of Cycling Conference

7:15 AM Registration


7:50 AM Welcome and Introduction

8:00 AM Cardiac Screening in Endurance Athletes -Anne Albers MD

9:00 AM Overtraining and Underperformance.  Combining Sports Medicine and Sports Science– Kevin Sprouse MD

10:00 AM Break

10:10 AM Cardiac Risk of Endurance Training -Anne Albers MD

11:10 AM Medical Coverage of Cycling Events -Keith Borg MD

12:10 PM Lunch


1:30 PM Research Presentations

2:30 PM Unique Sports Medicine Concerns of the Female Cyclist -Gloria Cohen MD

3:30 PM Adjourn (Final instructions about ride Hyatt 4p, dinner Marigold 7p (carpool 630p))

4:00 PM Group ride

7:00 PM Group Dinner – Sunbird Mountain Grill, 230 Point of the Pines Dr

SUNDAY, August 14th, 2016 – Medicine of Cycling Conference


7:30 AM Registration

8:00 AM Physical Therapy Bike Fit Accommodations – Greg Robidoux PT

9:00 AM Acute Cycling Injuries or panel discussion on race safety -Mark Greve MD

10:00 AM Break

10:10 AM Cycling Physiology and Physiological Testing– Inigo San Milan PhD

11:10 AM Pulmonary Limiters in Athletic Performance -Michael Ross MD

12:10 PM Break

12:20 PM Protecting Clean Sport: Global Advances in Drug Detection and Deterrence Efforts – Matthew Fedoruk PhD

You can find more information about registration here. Let us know if you have any questions!

The Truth About Cycling and Brain Injuries

Posted on March 11, 2016 by Courtney Barnes

Steve Broglio, Director of Research at Medicine of Cycling was interviewed by Bicycle Magazine about the potential of cycling related concussion leading to Chronic Traumatic Encephalopathy (CTE). Symptoms of CTE generally begin 8–10 years after experiencing repetitive mild traumatic brain injury.  In the early stages, CTE can cause decreased job performance, dizziness, and headaches. With progressive deterioration, symptoms may include memory loss, social instability, erratic behavior, and poor judgment.  As the disease progresses, symptoms include dementia, decreased muscle coordination and muscular slowing, stuttering speech, tremors, hearing loss, and suicidality.

CTE has been linked to suicide among athletes in high frequency impact sports, most famously American Football.  As of December 2012, thirty-three former National Football League (NFL) players had been diagnosed with CTE by post-mortem brain autopsy. Famous football players diagnosed post-mortem include Detroit Lions lineman Lou Creekmur, former Houston Oilers and Miami Dolphins linebacker John Grimsley, and former Tampa Bay Buccaneers guard Tom McHale.  An autopsy conducted in 2010 on the brain of Owen Thomas, a 21-year-old junior lineman at the University of Pennsylvania who committed suicide, showed early stages of CTE.  He is one of the youngest to be diagnosed with this condition.

Read the full article here:

Registration open for MOCC 2016

Posted on February 19, 2016 by Courtney Barnes

Registration is now open for the annual Medicine of Cycling Conference August 12 - 14, 2016 at the USA Cycling National Conference Center in Colorado Springs. We are pleased to announce fee reductions for this year. CME and CUE credits available. There is an exciting line up of speakers. UCSF is once again the CME sponsor for the event. Use this link to register now:

There are 3 option under the Registration Type. The first is for physicians registering for the main conference the second for everyone else registering for the main conference. The third option is for those who want to do the 2 day hands on fit course and conclude with a single day of the main conference.

Here is a tentative schedule for the Medicine of Cycling Conference:

SATURDAY, August 13, 2016 – Medicine of Cycling Conference

7:15 AM Registration


7:50 AM Welcome and Introduction

8:00 AM Cardiac Screening in Endurance Athletes -Anne Albers MD

9:00 AM Medical Complications due to Training and Overtraining – Kevin Sprouse MD

10:00 AM Break

10:10 AM Cardiac Risk of Endurance Training -Anne Albers MD

11:10 AM Rehab and Recovery from Injury -David Castol MD

12:10 PM Lunch


1:30 PM Research Presentations

2:30 PM The Female Cyclist -Gloria Cohen MD

3:30 PM Adjourn (Final instructions about ride Hyatt 4p, dinner Marigold 7p (carpool 630p))

4:00 PM Group ride

7:00 PM Group Dinner – Marigold Cafe and Bakery – 4605 Centennial Blvd., Colorado Springs

SUNDAY, August 14th, 2016 – Medicine of Cycling Conference


7:30 AM Registration

8:00 AM Physical Therapy Bike Fit Accommodations – Greg Robidoux PT

900 AM  Acute Cycling Injuries or panel discussion on race safety -Mark Greve MD

10:00 AM Break

10:10 AM Cycling Physiology and Physiological Testing– Inigo San Milan PhD

11:10 AM Pulmonary Limiters in Athletic Performance -Michael Ross MD

12:10 PM Break

12:20 PM Protecting Clean Sport: Global Advances in Drug Detection and Deterrence Efforts – Matthew Fedoruk PhD

1:20 PM Adjourn

Let us know if you have any questions or comments!

Call For Abstracts for 2017 Medicine of Cycling Conference

Posted on January 29, 2016 by Courtney Barnes



We are pleased to announce the call for Abstracts for the 2017 Medicine of Cycling Conference, to be held August 18-20, 2017 in Colorado Springs, CO.  Our goal is to provide a forum where researchers and clinicians can disseminate research and clinical case studies. If you are a researcher or clinician and are interested in presenting original research or a case reports at our conference, we invite you to submit your original research papers now through April 15th, 2017.

We encourage abstract submissions in a variety of areas, however, all submissions must be relevant to cycling medicine.  Both quantitative (including data) and qualitative (program descriptions, educational interventions, etc) are acceptable, however previously published data will not be accepted.  Submitted abstracts will be reviewed for relevance and quality, and highly ranked abstracts will be invited to give a podium presentation (10-minute presentation followed by a 5-minute Q&A).  Some abstracts may be invited to provide a poster presentation.  Research presentations are likely to occur on August 19th.


Original Research

Abstracts must be no longer than 450 words and should be structured as follows:


Author(s)* full names, degrees and affiliation. 

Context: Write a sentence or two summarizing the rationale for the study, providing a reason for the study question and/or uniqueness of study. Objective: State the precise objective(s) or question(s) addressed in the report, including a priori hypotheses if applicable. Design: Describe the overall study design of the project reported (e.g., randomized controlled trial, crossover trial, cohort or cross-sectional). Setting: Describe the environment in which the study was conducted to help readers understand the transferability of the findings, (e.g., patient clinic, research laboratory or field). Patients or Other Participants: Describe the underlying target population, selection procedures (e.g., population based sample, volunteer sample or convenience sample) and important aspects of the final subject pool (e.g., number, average age, weight, height and measures of variance, years of experience or gender). Interventions: Interventions are the independent variables in the study. Describe the essential pieces of the experimental methods, types of materials, measurements and instrumentation utilized, data analysis procedures and statistical tests employed. Main Outcome Measures: Clearly identify primary or critical dependent variables that support the primary objective(s) of the study. Indicate the statistical analysis employed to answer the primary research objective(s). Results: The main results of the study should be given: When appropriate, include descriptive data (e.g., proportions, means, rates, odds ratios or correlations), accompanying measures of dispersion (e.g., ranges, standard deviations or confidence intervals) and inferential statistical data. Results should be accompanied by the level of statistical significance (ie p-value). Conclusions: Summarize or emphasize the new and important findings of the study. The conclusion must be consistent with the study objectives and results as reported. If possible, relate implications of the findings to the medicine of cycling.

*Authors of accepted abstracts will be asked to disclose funding sources and potential conflicts of interests.

Case Reports

Abstracts must be no longer than 600 words and should be structured as follows:


Author(s)* full names, degrees and affiliation. 

Background: Include the individual’s age, sex, sport discipline, pertinent aspects of their medical history, a brief history of their complaint and physical findings from the examination. Differential Diagnosis: Include all possible diagnoses suspected based on the history, mechanism of injury, and the initial clinical examination. Treatment: Include the physician’s evaluation and state the results of diagnostic imaging and laboratory results if performed. The final diagnosis of the injury or condition and subsequent treatment and clinical course followed should be clearly detailed. Relevant and unique details should be included, as well as the final outcome of the case. Uniqueness: Briefly describe the uniqueness of this case such as its mechanism, incidence rate, evaluate findings, rehabilitation, or predisposing factors. Conclusions: Include a concise summary of the case as reported and highlight the case’s importance to the medicine of cycling and provide the reader with a clinical learning opportunity. 

*Authors of accepted abstracts will be asked to disclose funding sources and potential conflicts of interests.

Submission Information and Deadlines

Abstracts should be submitted via email to Medicine of Cycling at medofcycling @

Abstract Submission Deadline:  April 15th, 2017

Abstract Acceptance/Non-acceptance email notifications: May 15th, 2017


The following prizes will be awarded:

1 Best Student/Resident/Fellow Original Research Abstract Award: waived conference fee

1 Best Student/Resident/Fellow Case Report Award: waived conference fee

1 Best Professional Original Research or Case Report Abstract: waived conference fee

The waived conference fee is contingent upon presenting at the conference.

We look forward to your submissions!



Medicine of Cycling Research Task Force

Articles on Road Rash and Head Injuries from MOCC 2015 Participant, Paul Engler RN

Posted on January 6, 2016 by Courtney Barnes

One of our very own MOCC 2015 participants, Paul Engler, RN has recently had two articles published in Performance Conditioning: Cycling's newsletters.

You can read them here:

Head Injuries from Medicine of Cycling Conference

Dealing with Road Rash from Medicine of Cycling Conference

Please share with your cycling community!

Medicine of Cycling Concussion Cards now in Japanese!

Posted on October 2, 2015 by Courtney Barnes

We are thrilled that Medicine of Cycling is becoming a part of cycling communities all over the world! Dr. Kiyonori Tomiwa has kindly translated our concussion cards to be a reference for the Japanese cycling community.

You can find the Japanese translated card here.

Road rash care: Cycling bravery has some consequences, but nothing a little post-bike ride wound care can’t fix

Posted on September 25, 2015 by Courtney Barnes

Medicine of Cycling: Road Rash

*originally published on LifeBalance

By Paul Engler, RN, BSN

Cycling has many health benefits. However, there is always a risk of injury or medical issues. As a cyclist, a nurse and event volunteer, I find myself helping injured cyclists, doing medical assessments and giving treatment. I wanted a new resource to educate myself on injuries, prevention, improving care and educating the public. My solution was to attend the yearly conference in Colorado Springs presented by Medicine of Cycling™. It turned out to be wonderful resource for medical professionals who are involved in the sport. The Medicine of Cycling™ mission is prevention of crashes with injuries and rehabilitation with performance to help cyclists across the country get better care and help them achieve their goals.

This organization is affiliated with USA Cycling and is made up of a panel of sports doctors from around the country and teaching universities. Professional team doctors from Cannondale Garmin and Team Type 1 sit on the panel and were present and ran lab simulation. They were excellent teachers and presenters. If you’re a bicycle racer, USA Cycling would be familiar as the organizing and sanctioning body for bicycle racing in the United States. MOC looks at evidence-based research and methods to treat or prevent cycling related medical problems. This year’s focus covered a number of areas with experts across the nations. If you are wanting to know more, see the MOC website

This is the first of a few articles on what I learned at MOC and I hope you find interesting and useful. I shall keep them brief and to the point and start with the least serious to the most serious injuries to follow in the coming months. Most crashes will have abrasions or lacerations. Studies at the this conference showed around 60-70% of all injuries from the skinned knee of a child to the full body road rash of the back, shoulder, hip and knee of the crit racer. “Road rash” is the common term and the most common injury, and is very painful.

Event planners  such as race directors or large ride leaders can stock up their first aid kits. Clubs and race teams should keep a well-stocked first aid kit in their trailers. It’s a nice service to add to a rider’s membership. Also make sure they are covered under the club’s or USAC insurance policy and get the paperwork filled out. It’s best to buy supplies on online as the selection is greater and the cost is affordable. A formal medical plan should be part of your event to respond and treat injured cyclists.

Road Rash Treatment
This is assuming bumps and bruises with minor swelling, no fractures, lacerations or head injuries which have been well ruled out. If you have more serious injuries, road rash issues are the least of your worries. If any doubts have them driven to urgent care or activate EMS.

1. Dirty wound with possible contamination? Gravel, glass, cow poop (this happened in the Dirty Kanza gravel ride this year leading to secondary infection) or wet, slippery, muddy conditions increase the risk for infections. Elbows and knees are more at risk as the organism will get inside  the bursa of the joint where it can grow and is not easily washed out. Go to step 2 for a dirty wound. If NOT, skip 2. and go to step 3. Hydrogen Peroxide is very good at killing germs but it kills live tissue as well so you need to use good judgment.


For a cow poop wound while on gravel or trail, scrub the wound bed really well. Mountain Bikers get into dirt and rocks. Goose poop may be found on lake trails. With wet, slippery, or muddy pavement, a cyclist will lose traction and fall down.

2. A. Irrigate with normal saline or store bought bottled water. Normal saline reduces some of the sting while washing out a wound.

B. Use sterile scrub brush with hydrogen peroxide and scrub out wound and remove all foreign bodies.

A medical sterile scrub brush is used to get the grit out.

Hate to say it but it’s going to hurt a lot. However, a $1500.00 day hospital bill while they treat you for infection for not cleaning out the wound properly is going to hurt more. If you cannot get all the crud out, go to the ER as they have tools such as VERSAJET hydro-surgery system which enables a surgeon to precisely select, excise and evacuate nonviable tissue, bacteria and contaminants from wounds and soft tissue injuries. Stronger anti-infectives and antibiotics can be prescribed with sedation to reduce the pain of the procedure.

4. Pat the wound dry and use triple antibiotic cream, then a
non-stick bandage such as Tegaderm. This provides a good barrier and healing environment. You can buy BSN Tegaderm on the internet in rolls to place in club or first aid bags.

5. For the second layer, apply a tegaderm4×4 gauze over Tegaderm as padding and base for final compression layer.

6. Compression bandages are used to hold the bandage in place. Shoulders, elbows and knees are hard areas to hold the bandage in place. Cover-Roll® Stretch is good product to use on shoulders as well as general areas of the forearm. Coban can be used as well. These products come in rolls to be cut to length and can be kept in first aid bags. Cover-Roll® Stretch runs about $10-$14 dollars a roll. The sock or tube bandages are very nice too. Either place over the CoverRoll or over the gauze as shown below.


Removal is done in the shower. The bandage will fall off easier with minimal sticking to the wound causing less discomfort. Wash the wound out gently and with shower water and then allow drying and re-bandaging starting with step 4 above.

Signs of infection include increased pain with swelling redness or streaking, yellow or white drainage, or not healing. Go to urgent care or doctor for assessment. Crashing in wet conditions increase the risk for secondary infection on knees and elbows. Infection may lead to hospital admission so it’s good to catch early. If you are a race or event director, send extra bandages in a plastic bag with the person to take home till they can get to the drug store or their doctor.

Paul Engler, BSN, RN has been working in medicine for 25 years. A cyclist for more than 30 years, he has enjoyed riding for recreation, racing, and gravel grinding. Paul is a member of the Lawrence Bike Club, Kaw Valley Bike Club, Medicine Of Cycling, and USA Cycling.

2015 Conference Attendee Information

Posted on August 12, 2015 by Courtney Barnes

Dear Registrant,

We look forward to seeing you at the upcoming Medicine of Cycling Conference on August 14-16, 2015 at the USA Cycling Headquarters in Colorado Springs, CO.  The course is rapidly approaching and we wanted to take just a moment to provide some additional information before your journey to Colorado Springs.

Conference Location

The entire conference will be held at USA Cycling Headquarters at 210 USA Cycling Point, Colorado Springs, CO 80909. You can choose to ride, drive, or walk between Hyatt House and USA Cycling; it’s only 5-minute walk. Hyatt House has complimentary breakfast near the main entrance to the hotel. Our group is often the largest and most gregarious, so join us and fellow course participants before heading over to USA Cycling for the lectures. Lunch and snacks will be provided onsite at USA Cycling on Friday and Saturday.

Presentations and Handouts

This is a greener” conference, which means presentations will be online and available for you to view on your personal computer or mobile device along with the presenters if you choose. Some of the presenters will have their presentations or syllabus outlines online ahead of the conference; participants will be able to view these at***** starting Monday evening, August 10.

Evaluation and CE Certificates

This year’s course evaluation will also be online and a link to the survey will be available on the day of the course on the presentation page above. Complete your daily evaluations of the speakers or sessions online, and then complete an overall evaluation for the course. The surveys will work on a smartphone, however a laptop or an iPad is easier to use. Once you complete the overall course evaluation, your CE/CME certificate will be e-mailed to you.

Questions, Comments, Help?

My email address is or and my cell is 415-272-0357. You may also contact Aaron Goldberg 414-218-5031

We are excited to have you involved with Medicine of Cycling, and we look forward to seeing you in Colorado Springs in a few days. Thank you for your participation!


Anna, Aaron, Mark and the conference planning crew.

See below for conference details and information about the Velodrome Party and Saturday night’s Marigold dinner.


MECC/Medical Emergencies in Cycling Course

This is a hands-on activity for those of you who want to be more involved with teams, races, or just prepared on your local rides. Registration is $225 and is separate from the rest of the conference. If you are unsure if you are registered, please e-mail Space is still available

Location: USA Cycling, 210 USA Cycling Point, Colorado Springs, CO 80909

Registration opens at 7:15 am, and the course begins promptly at 8:00 am.

Bike Fit University and Hands on Workshop

This is a 2-day work shop that starts on Friday with a day of lectures, and wraps up with a space limited hands-on clinic led by a group of expert fitters from a variety of specialties. Certificates will be handed out at the completion of the sessions.

Location: USA Cycling, 210 USA Cycling Point, Colorado Springs, CO 80909

Registration opens at 7:15 am, and the course begins promptly at 8:00 am.

Friday Night Velodrome Party

We hope you can join us as a guest at our USA Cycling-sponsored Velodrome Party just for our group from 6:00 – 9:00 pm. If you would like to ride on the track, please arrive to the track with your cycling shoes, pedals, clothes, and a helmet no later than 6:00 pm, and send your bike size to The track staff has planned a clinic for 8 riders and has 8 bikes reserved for us.

The dinner and party will start at 7:00 pm. (Please note that no alcohol will be served until all riders are off the track.)

Location: 7-Eleven Velodrome, 250 South Union Blvd, Colorado Springs, CO 80910


Medicine of Cycling Conference

We will begin registration on Saturday morning at 7:15 am, but we encourage you to have your first breakfast and coffee at the hotel. We have a big number of conference participants at the Hyatt, so it is a good place to meet your fellow conference attendees. We will have snacks, coffee, and lunch provided during the conference.

Location: USA Cycling, 210 USA Cycling Point, Colorado Springs, CO 80909

Saturday Afternoon Bike Ride

We will meet in front of the HYATT House hotel at 4:00 pm for a 20- to 30-mile route. Mark will drive the broom wagon. You can rent bikes from Criterium Bicycles in Colorado Springs -

Saturday Evening Dinner

This has become one of our favorite parts of the conference, delicious dinner at Marigold Café. We have prepared an incredible menu especially for the conference with about 80 other cycling medical professionals. If you would like to attend and have not yet registered for dinner, bring $40 check or cash to us at any point during the conference. We encourage car-pooling to the dinner, meet at HYATT House lobby at 6:30 pm. Dinner starts at 7:00 pm.

Location: Marigold Cafe and Bakery, 4605 Centennial Blvd, Colorado Springs, CO.


Continuation of the Medicine of Cycling Conference and departures.



For our out of town guests, you can access local weather information at and use zip

code 80919.

Hotel Contact Information                                               

HYATT house Colorado Springs

5805 Delmonico Drive

Colorado Springs, CO 80919

Phone: (719) 268-9990


Research Review: Ulnar and Median Nerve Palsy in Cyclists

Posted on July 31, 2015 by Alynn Kakuk

Ulnar and Median Nerve Palsy in Cyclists

Patterson JM, Jaggars MM, Boyer MI. Ulnar and median nerve palsy in long-distance cyclists. A prospective study. Am J Sports Med. 2003 Jul-Aug;31(4):585-9. PubMed PMID: 12860549.



Prior to this study in 2003, there have been case studies and descriptions of “cyclist palsy” (ulnar nerve compression at Guyon’s canal in cyclist) in medical literature but there has been no research to determine the prevalence of cyclist palsy. The ulnar nerve courses in the medial forearm and gives off the dorsal cutaneous branch of the ulnar nerve prior to travelling through Guyon’s canal, thus the dorsal cutaneous branch of the ulnar nerve is preserved in cyclist palsy. There are several branches of the ulnar nerve in the hand including the motor branch to the hypothenar muscles, deep motor branch of ulnar nerve, and sensory component of the ulnar nerve. Understanding of the complex anatomy of the ulnar nerve provides better localization of nerve lesions. The authors of the study randomly chose 25 riders who were participating in a 600 km bicycle ride to complete a questionnaire and obtained baseline ulnar and median nerve (motor and sensory) function (with extensive motor and sensory testing). After completing the 600 km bicycle ride, the subjects had repeat nerve testing and questionnaires. Subjects were almost equal male:female (13:12), average age 33.7, cycled on average 139 km/week, mostly intermediate level cyclists (13/25), and without systemic illness (HIV/AIDS, diabetes, thyroid disease or neurological). Three riders had symptoms of nerve compression prior to the study (numbness in ulnar nerve distribution in one hand, +Phalen’s in one hand, and numbness in digits 4-5 with elbow provocative testing in three separate subjects). After the 600 kn bicycle ride, 36% of subjects had motor symptoms, 10% had sensory symptoms, and 24% in both motor and sensory symptoms. Only 30% of subjects had neither sensory nor motor symptoms. The authors concluded that there was no difference in symptoms in rider ability or whether mountain or road cyclist when assess motor function. There was however a greater incidence of sensory changes in mountain bikers, which the authors discuss, may be due to less handlebar positions. With fewer positions, riders may not be readjusting hands as frequently causing more compression on nerve.


Questions for discussion:

  1. This study suggests that cyclist palsy is very common with 70% of the subjects having either sensory or motor symptoms. This was a very small study with only 25 subjects. Is the prevalence of cyclist palsy in all cyclists? What is the prevalence of cyclist palsy in professional cyclists?
  2. In this study, there was no difference in motor symptoms but there was a difference in sensory symptoms in mountain bikers compared to road cyclist. The authors discuss this could be due less options for hand positioning in mountain bike bars. Would the use of bar ends, togs ( or an ergonomical grip (such as change the symptoms of nerve compression?
  3. This study was performed over a short time period. How long do subjects have the symptoms of nerve compression and is there any electrodiagnostic evidence of nerve injury.


Author: Alexandra Flis, MD

Research Review: Endofibrosis of the Iliac Arteries

Posted on July 22, 2015 by Alynn Kakuk

The Danger of the Drops- A Review of Peach et al. 2011

A Question

Bradley Wiggins broke the world record for longest distance covered on a bicycle in one hour by riding 54.526km on June 7th, 2015. Because 90% of the resistance when biking on a level surface above 12mph comes from air drag and 70% of that drag comes from the rider [1], significant attention was paid to finding the most aerodynamic bike fit possible for Bradley. Among other things, this position included a lot of forward bend and flexion at the hips.

As a bike fitter in Oakland California, I spend a lot more time fitting people to climb hills than to time trial, but I do see a fair number of triathletes for whom the generally level cycling courses make aerodynamics paramount. I've heard that spending a lot of time exercising in this bent over position can cause thickening of the walls of the large arteries in the abdomen.

When I fit someone in an aggressive amount of hip flexion and forward bend, am I putting them at risk for vascular damage? As usual, I turned to the research literature to find the answer.

Some Data

A group of vascular surgeons and sports scientists in the UK and Netherlands published a systematic review on all the research on iliac artery damage during endurance exercise [2]. They found 47 relevant studies, the highest quality studies were case-control studies with no randomized controlled trials found on the topic. Most of the cases they found were of young endurance athletes with exercise induced cramping that didn't improve with physical therapy. What was going on with these athletes? To understand this problem, we'll need to cover a little anatomy first.

Where is the external iliac artery?

The external common iliac arteriers are a pair of large blood vessels that come off the aorta and the external iliac branch supplies fresh oxygenated blood to the legs. All the blood to the quads, lower hamstrings and everything below the knee comes from this artery.

Untitled Image from the Visible Body ipad app

What limits blood flow in the iliac artery in otherwise healthy endurance athletes?

Endofibrosis is a thickening of the inner wall of the blood vessel called the tunica intima. This thickening makes the internal diameter of the blood vessel smaller and thus limits blood flow. The thickening is usally 2-6cm long and 90% occur in the external iliac artery. Most cases (85%) occur on only one side of the body with the left begin more commonly affect than the right (52% to  90% left sided depending on the study).

What causes endofibrosis of the external iliac artery?

Many causes have been proposed, here are the most common

  1. Repetitive stretching and bending of the arteries while exercising in a bent-over position.The problem is most common in speed skaters and endurance cyclists.
  2. Enlargement of the psoas muscle under the external iliac artery.The larger the psoas muscle the more it will push up on the external iliac artery, causing it to bend at a sharper angle. Cyclists with endrofibrosis have been found to have a thigh circumference 3cm larger on the affected side.
  3. Fixation of the psoas muscle.Excessive fascial connetions, scar tissue or even the extra blood vessels the grow into the psoas from training can tether the artery and make it kink.
  4. Unusually long iliac arteries.A longer artery has to kink more to fit in the same space. The length of the artery is most likely genetic.  A very long artery can cause kinking that limits blood flow even without endofibrosis.
  5. Unique systemic factors.Diabetes compromises the vessel walls. Abnormal methionine metabolism has been found in 75% of one cohort of patients with endofibrosis

Untitled2This image from the Visible Body ipad app shows how the external iliac artery makes a sharp turn along the back side of the abdomen before exiting the front of the pelvis.

How Common is Iliac Artery Blood Flow Impairment?

In the general population the condition is very rare, in elite endurance athletes it may be as high as 10-20% although the difficulty in diagnosis make estimates uncertain. A survey of cyclists with the condition found that:

  • All of the cyclists had ridden an average of 9,009-12,427 miles per year (14,500 to 20,000 km/yr) for many years. That's 173 to 239 miles per week year after year.
  • 88% were men, but this may be skewed by the fact that there are more male elite endurance athletes

This rare condition is most common in cyclists but has also been reported in other sports with a bend-over posture such as speed skating, and cross-country skiing, but a few cases have been reported in sports that are more upright such as endurance running, rugby, soccer, and body building.

Am I at risk?

The most common symptom is a cramp and a feeling of swelling, numbness or pain in the buttock, thigh or calf on one side of the body.  The pain may be mild. Professional cyclists Hayden Godfrey described his symptoms of endofibrosis as feeling like his leg was falling asleep and losing power. Because these  symptoms are somewhat vague and tend to go away after exercise and because endurance athletes are accustomed to feeling discomfort in their legs,  people tend to go un-diagnosed for a long time.

Fortunately Schep et al. reviewed the research and found that when all of the following four signs and symptoms  were present, they were able to correctly diagnose iliac endodfibrosis 79% of the time [3].

Four signs and symptoms that leg cramping, swelling, numbness or pain is coming from endofibrosis:

  • The complaint goes away less than 5 minutes after stopping exercise. More than 3 out of the 6 major leg muscles are involved. (sens: 0.97,  spec: 0.29)
  • More than 3 out of the six major muscle of the leg are involved (sens: 0.48, spec: 0.94)
  • Femoral bruit with hip in extension- Abnormal blood vessel sounds found using a stethoscope (sens: 0.36, spec: 0.94)
  • Normal lower back flexibility (sens: 0.91, spec: 0.29)

What is the treatment?

If you are concerned that you may have this condition, schedule an appointment with your doctor to discuss it. Further testing may be warranted such as measuring blood pressure at the arms and ankles immediately after cycling. Treatments vary depending on the cause of the blood flow restriction.

Ankle Brachial Index- Wikipedia Creative Commons

Untitled3Blood pressure is compared between arms to detect arterial blood flow limitations. Wikipedia.

For minor cases in cyclists the following treatments are often sufficient:

  • reducing the hip flexion angle by
    • spending less time in the drops
    • moving the saddle forward
    • raising the handlebars
  • reducing psoas hypertrophy by not pulling up on the pedals
  • reducing riding time

Ryan Cox- Wikipedia creative commons license

More severe cases may require one to give up cycling or undergo surgery to continue cycling.  Many professional cyclists have undergone surgery for arterial endofibrosis and have returned to professional competition without incident. However, Ryan Cox's tragic death on August 1st 2007 at age 28 from endofibrosis surgical complications is a painful reminder of the risks of this condition.


I think it is worth emphasizing that this is a rare condition outside of professional cycling and speed skating. If you are cycling less than 173 miles per week and/or your position is not extremely low (ie your thigh is not hitting your chest) then it seems you have little to worry about. It is the combination of a low position and high mileage that increase the risk for this condition. Elite cyclists and high mileage recreational riders (ie Iron Man triathletes) should take any lower extremity symptoms seriously and seek medical attention as the condition does not improve on its own.


  1.  Burke,E. Serious Cycling 2nd ed. Human Kinetics 2002
  2. Peach- Endofibrosis and Kinking of the Iliac Arteries in Athletes- A Systematic Review. 2011
  3. Schep G, Schmikli SL, Bender MH, Mosterd WL, Hammacher ER, Wijn PF. Recognising
    vascular causes of leg complaints in endurance athletes. Part 1: validation
    of a decision algorithm. Int J Sports Med 2002;23(5):313e21
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About the Author: Bryan Ausinheiler is a physical therapist, personal trainer and bike fitter with a clinic and studio in Oakland California.