Research Blog: Strategies for Maintaining Muscle Mass When Injured

Posted on March 14, 2015 by Alynn Kakuk

Article Review:

Strategies to maintain skeletal muscle mass in the injured athlete: Nutritional considerations and exercise mimetics

Benjamin T. Wall, James P. Morton & Luc J. C. van Loon (2015) Strategies to maintain skeletal muscle mass in the injured athlete: Nutritional considerations and exercise mimetics, European Journal of Sport Science, 15:1, 53-62. 

Article Summary:

Injuries in cycling can be caused by crashes, overuse or from poor bike fit. Regardless of the cause of a severe injury, recovery often involves a period of immobilization and associated muscle disuse, which can result in a rapid muscle loss and reduced functional capacity.

The decline in muscle mass and strength is most profound during the first 1–2 weeks post-injury, when interventions are not conventionally considered a priority for the athlete. The muscle loss is primarily due to a reduction in basal muscle protein synthesis rate and the development of anabolic resistance to dietary protein intake.

Although further work is required to translate research findings directly to managing athlete injuries, the following recommendations are presented for practitioners to limit the loss of muscle after injury in their athletes.

Key nutritional considerations during the period of disuse:

  • Daily protein intake of 1.6–2.5 g per kg of body mass:
    • Ideally through regular (4-6 times daily, every 3-4 hrs) consumption of adequate amounts (20–35 g) of rapidly digested protein sources with a high content of the branched chain amino-acid, leucine (2.5–3 g); and
    • Including dietary protein with breakfast and prior to sleep.
  • Intake of specific nutritional compounds that may also promote the maintenance of muscle protein synthesis rates such as:
    • omega-3 fatty acids, branched chain amino acids (including leucine), creatine, and HMB (a metabolite of leucine).
  • It is challenging for athletes to achieve optimal macronutrient intakes to maintain skeletal muscle mass but prevent any gains in fat mass, due to the reduced energy expenditure during the recovery period.

Additional interventions that can attenuate muscle loss, include:

  • Utilizing neuromuscular electrical stimulation (NMES) to invoke involuntary muscle contractions, which can stimulate muscle protein synthesis rates.
  • Prescribing an exercise stimulus (particularly resistance exercise) for the uninjured muscle groups to minimize or prevent unwanted reductions in regional muscle mass that may result in reduced whole-body muscle mass and affect metabolic function. 

Questions for Discussion:

Recovery from cycling injuries may involve total or partial immobilization. What are the major causes of injury in cyclists that cause total or partial immobilization? What are specific considerations for an injured cyclist during rehabilitation?

NMES represents a practical strategy for maintaining a degree of physical activity during the early stages of recovery from injury. The potential for structured and supervised NMES to maintain muscle protein synthesis rates, metabolic health and muscle mass and function during more prolonged rehabilitation requires future investigation. It would be worthwhile to consider developing optimal parameters for NMES protocols, in terms of duration, stimulation intensity and other specific parameters, for recovery from common cycling injuries.

In addition, although beyond the scope of this article, recent studies have examined the effect of NMES on post-exercise recovery. Future work to develop parameters for NMES could also investigate the potential benefits of NMES and optimal protocols for post-race recovery for cyclists competing in stage races.

The summarized dietary manipulations can help to minimize muscle loss during injury. What are the effects of these manipulations on long-term recovery of muscle mass and strength?

Future studies are warranted to enhance our understanding of how the known acute effects of dietary manipulation impact upon long-term measures of muscle mass, function, rehabilitation time and the duration required to return to competition.

Written By: Felice Beitzel, PhD, LMT

Reviewed By: Alexandra Flis, MD

Research Blog: Aerobic Fitness Variables

Posted on March 2, 2015 by Alynn Kakuk

Article Review: Aerobic fitness variables do not predict the professional career of young cyclists.

Menaspà P1, Sassi A, Impellizzeri FM. Aerobic fitness variables do not predict the professional career of young cyclists. Med Sci Sports Exerc, 2010;42(4):805-12.

Article Summary:
In sport, organizations look to the junior ranks for new talent. Predicting who will become a successful professional athlete based on their performance in the junior ranks is difficult (e.g. In American football, Tom Brady was a 6th round draft pick and is now considered one of the all time greats). Individual aerobic capacity is thought to be more important in a sport such as cycling, The goal of this study was to determine if aerobic fitness variables derived from traditional VO2 max testing could predict future success as a pro cyclist.

The study used retrospective data (1996-2002) from metabolic testing performed on 309 cyclists ages 17 to 18. Seventy two of the juniors competed for their respective national cycling team. In December 2008, researchers looked at their cycling careers. Cyclists were considered to be a professional cyclist if they had been on a UCI team for at least three years. Further, professional cyclists were subdivided into further categories including lower ranked professionals versus ProTour cyclists and their cycling style (climber versus sprinter versus time trialist).

Overall, none of the six measurements derived from V02 max testing nor any of the anthropometric variables was predictive of either becoming a professional cyclist or success at the professional level. There were some trends noted for some variables that may increase or decrease the odds of success, especially for particular cycling styles. Other factors including economy, anaerobic characteristics, technical ability, tactical skills, mental fatigue, perception of effort and ability to recover are likely all other important variables for excelling at the professional level.

Questions for Discussion

1) I’m assuming this study was done only on male cyclists (it’s not clear in the paper but that’s my inference.). Would these same findings hold true for young female cyclists?

2) The role of doping and performance enhancing drugs is unclear. This paper was published in 2010. At the time, none of the cyclists who went on to pro careers had tested positive for performance enhancing drugs. Now that it’s 2015 and more facts have come out about doping at the professional level during this period, does the study still hold true? Was success as a professional based primarily on the athlete’s decision to use PEDs?

3) The average VO2 max of the juniors tested here was quite high (50th percentile VO2 max was 71.4 and the 10th percentile VO2 max as 62.4- still fairly high). How would this study look if the study was performed on a group of youth cyclists with a wider range of physiologic variables?

4) In light of athlete progression into the pro-tour who have previously tested below 62.4 VO2 max, FTP 60 and 20 mins average, how do we manage testing/quantifying young riders to ensure that ‘the numbers’ are developed alongside attributes such as tactical awareness, determination, ability to suffer and pure grit. More ‘purist’ European teams often quote these as key aspects of selection, often at the expense of watts and VO2 max etc.

Written by: Andy Pasternak, MD, MS

Reviewed by: Graham Theobald, BSc. (Hons), MSST

Research Blog: Biking and Bone Health

Posted on February 9, 2015 by Alynn Kakuk


Biking and Bone Health: The Facts



The street in front of our house turns sharply and soon my wife and I are punishing the drive train of our tandem up a 12% grade. At a combined weight of 330lbs and a combined continuous rep pull-up max of 35 reps, we clearly aren't your average bike monkeys. Nay, we are the larger, slower moving apes of the cycling world.

A spindly 130lb man flies past us up the hill with a weathered face that could say either 50+ years or 500,000 miles on a bicycle. He is clearly the master of this hill. His chiseled quads don't look weak, but as a physical therapist, I wonder about his bones. I have heard of professional cyclists having low bone density and shattering hips on falls that wouldn’t have broken the average person’s bones. I’ve heard that because of the high cadence even a power output of 300w only produces about 100lb of force per stroke; less bone-stimulating weight bearing force than walking. But what does the research say? Is cycling bad for your bones?


Bone is living tissue, it is constantly being broken down and rebuilt, piece by piece. Cells called osteoclasts eat away at the bone and cells called osteoblasts make new bone. Over the course of 7-10 years the entire bone will be replaced. The balance of bone breakdown and bone rebuilding is determined by internal and external factors. Low bone density is called osteopenia, dangerously low bone density is called osteoporosis. Here are some of the most important factors:

• Estrogen promotes more bone growth, a drop in estrogen results in a drop in bone density.
• Cortisol results in a reduction in bone growth and thus prolonged cortisol results in lowering bone density. Cortisol is the hormone released when the body is under stress.
• Age: After around age 30, slightly more bone is broken down than rebuilt and bone density declines with age.
• Diet: If one doesn't eat enough calcium (<1000mg/day), or doesn't get enough vitamin-D ( • Genetics: Genetic factors affect

• Repetitive impact such as running or weight lifting breaks down bone, but this same impact signals the osteoblasts to make more bone and they usually end up making more than was damaged. The larger the weight (including the body weight), the more impact and thus the more bone growth.


To answer my questions about bone density and cycling I searched through google scholar and PubMed until I found a Systematic Review on Cycling and Bone Health published in 2012 by Hugo Olmedillas and his research group in Spain [1]. They group examined all of the recent research and came to these conclusions

It’s True
People who just ride a road bike all the time, really do have worse bone density and it only gets worse with time

• 2/3 of the professional and master adult road cyclists could be classified as osteopenic [2]
• Both in professional and recreational cyclists, bone density has been found to be lower than in the general population [3,4]
• Nichols compared cylists to age-matched non-athletes. The cyclists lost more bone density over the course of the seven year study [4]
• Bone density in competitive cyclists gets worse as the racing season progresses [5]
• Low levels of bone density earlier in life may contribute to dangerously low levels (osteoporosis) later in life [6]

Some impact is better than none
Almost any exercise is better for your bones than just endurance cycling (except maybe swimming)

• Wilks et all found that sprint trained cyclists had higher bone density than endurance trained cyclists [7]
• Mountain bikers have been found to have better bone density than road cyclists. [13]
• Weightlifting builds bone density more than anything else [8].
• Duathletes and Triathletes had higher bone density than those who only did endurance cycling. [1]
• Adolescent runners had better bone density than their peers who were cyclists or non-athletes [9].

You can't just take more calcium. But a greater % of fat in the diet might help.

Calcium is like the bricks, impact is like the blueprints. Send a extra bricks to the construction site but no orders and nothing extra gets built. Except maybe a kidney stone...[10]
• Barry et al. tried to stave off the decline in bone density by giving a group of cyclists extra calcium but although it change their calcium levels after exercise, it didn't improve their bone density [11].
• Brown et al. showed a small uptick in bone density in the group that ate a higher percentage of their diet as fat for 12 weeks, with no difference in body mass or fat between groups [12].
• Although factors such as nutrition and endocrine (ie cortisol levels from the stress of long rides) are beginning to be studied in cyclists, initial results haven't shown levels far enough from normal to explain the low bone density [1].


Cycling itself doesn't reduce your bone density, it just doesn't do anything to help your bone density, and if cycling is all you are doing then you aren't doing much to help your bone density.

How to help your bone density:
• Adequate nutrition: 1000mg of calcium and 600U of vitamin D. Don’t remove fat from your diet.
• Weight bearing activity. Running, jumping and weight lifting are the most effective.

The catch:
The very same weight bearing exercise that builds bone density can cause fractures in those with very poor bone density when given in excessive doses.

The Solution:
If road cycling has been your exclusive form of exercise for more than a few years I recommend contacting your doctor to get your bone density checked. This is especially important if you have a history of smoking, are Asian or Caucasian, over age 60 and light. Then connect with a physical therapist to get exercises that will safely improve your bone density.


1. Olmedillas H, Gonzalez-Aguero A, Moreno LA, Casajus JA, Vicente-Rodriquez G. Cycling and Bone Health: A Systematic Review. BMC Medicine. 2012. 10.168
2. Medelli J, Lounana J, Menuet JJ, Shabani M, Cordero-MacIntyre Z: Is osteopenia a health risk in professional cyclists? J Clin Densitom 2009, 12:28-34
3. Nichols JF, Palmer JE, Levy SS: Low bone mineral density in highly trained male master cyclists. Osteoporos Int 2003, 14:644-649.
4. Nichols JF, Rauh MJ: Longitudinal changes in bone mineral density in male master cyclists and nonathletes. J Strength Cond Res 2012, 25:727-734.
5. Barry DW, Kohrt WM: BMD decreases over the course of a year in competitive male cyclists. J Bone Miner Res 2008, 23:484-491.
6. Rizzoli R, Bianchi ML, Garabedian M, McKay HA, Moreno LA: Maximizing bone mineral mass gain during growth for the prevention of fractures in the adolescents and the elderly. Bone 2010, 46:294-305.
7. Wilks DC, Gilliver SF, Rittweger J: Forearm and tibial bone measures of distance- and sprint-trained master cyclists. Med Sci Sports Exerc 2009, 41:566-573.
8. Heinonen A, Oja P, Kannus P, Sievanen H, Manttari A, Vuori I: Bone mineral density of female athletes in different sports. Bone Miner 1993, 23:1-14.
9. Duncan CS, Blimkie CJ, Kemp A, Higgs W, Cowell CT, Woodhead H, Briody JN, Howman-Giles R: Mid-femur geometry and biomechanical properties in 15- to 18-yr-old female athletes. Med Sci Sports Exerc 2002, 34:673-681.
10. Curhan GC, Willett WC, Rimm EB, Stampfer MJ. A prospective study of dietary calcium and other nutrients and the risk of symptomatic kidney stones.
11. Barry DW, Hansen KC, van Pelt RE, Witten M, Wolfe P, Kohrt WM: Acute calcium ingestion attenuates exercise-induced disruption of calcium homeostasis. Med Sci Sports Exerc 2011, 43:617-623
12. Brown RC, Cox CM, Goulding A: High-carbohydrate versus high-fat diets: effect on body composition in trained cyclists. Med Sci Sports Exerc 2000, 32:690-694.
13. Warner SE, Shaw JM, Dalsky GP: Bone mineral density of competitive male mountain and road cyclists. Bone 2002, 30:281-286

Written By: Bryan Ausinheiler, DPT, CSCS

Reviewed By: Alfonso Lopez

About the Author
Bryan Ausinheiler is a Physical Therapist, Personal Trainer and Bike Fitter in Oakland California. Find more of his writing at his blog: Find more about his clinic and fitting studio at

Call for Abstracts for 2015 MOCC

Posted on January 21, 2015 by Alynn Kakuk

Call for Abstracts for 2015 Medicine of Cycling Conference

Medicine of Cycling is pleased to announce the Call for Abstracts for our annual conference to be held August 14-16, 2015 in Colorado Springs, CO.  If you are a researcher and are interested in presenting at our conference, we invite you to submit your original research papers now through April 30th, 2015.

We encourage abstract proposals in a variety of areas, however, the abstract must be relevant to cycling medicine.  Both quantitative (including data) and qualitative (program descriptions, educational interventions, etc) are acceptable, but published data cannot be submitted.  Submitted abstracts will be reviewed for relevance and quality, and highly ranked abstracts will be invited to give an oral presentation (limited to 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 15th.


The following prizes will be awarded:

2 Best Student/Resident/Fellow Abstract Award: 2015 waived conference fee

1 Best Professional Abstract: 2015 waived conference fee

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



Abstracts must be no longer than 300 words (excluding a single Table or Figure) and should address the following:

  • Objective
  • Methods
  • Results
  • Significance to Cycling Medicine

Please include full author names, degrees and institutional affiliation if applicable.  Authors of accepted abstracts will be asked to disclose potential conflicts of interests.



Abstract Submission Deadline:  April 30th, 2015

Abstract Acceptance/Non-acceptance email notifications: May 15th, 2015


Abstracts should be submitted via email to Alynn Kakuk, DPT at

Members of the Research Task Force will be involved in the selection process.


We look forward to your submissions!



Medicine of Cycling Research Task Force

Research Blog: Carbohydrates for Training and Competition

Posted on January 19, 2015 by Alynn Kakuk

Article Review #2:  Carbohydrates for Training and Competition

Burke LM, Hawley JA, Wong SH, Jeukendrup AE. Carbohydrates for training and competition. Journal of Sports Sciences, 2011;29(S1):S17-S27


Article Summary:

There is an enormous amount of interest and research in the subject of carbohydrates as fuel and the relationship to performance in sports. “Carbohydrate availability” is often discussed in regards to timing of ingestion relating to exercise, as well as the overall daily intake. This subject generates significant interest in athletes and those involved in their care.

This article reviews carbohydrates for daily refueling and recovery, acute refueling strategies, glycemic index as well as intake during and after prolonged exercise. The key findings are:

  • When training at high intensity, daily carbohydrate intakes should match fuel needs of training and restoration. This starts at 3-5 g/kg/day to as high as 8-12 g/kg/day.
  • If the period of refueling is less than 8 hours, time is of the essence – begin refueling as soon as practical; early refueling will be enhanced by higher rate of carbohydrate intake in small and frequent feedings.
  • Adding protein when carbohydrate intake is sub-optimal will enhance glycogen storage.
  • There remains debate on manipulating the glycemic index – this still needs to be individualized to the specific event and the athlete.
  • In events longer than 2-3 hours; higher intakes of carbohydrates, up to 90 g/hr., require products providing “multiple transportable carbohydrates” (glucose:fructose in 2:1 mixtures) which can help achieve higher rates of oxidation of carbohydrate.
  • During shorter events, 45-75 minutes, mouth rinsing of a carbohydrate mixture or intake of a very small amount of carbohydrate can improve performance through a “non-metabolic” role involving the central nervous system.

In addition, low carbohydrate intake, or “train low/compete high”, may present a new paradigm for training adaptations. Recent research examining the effect of exercising at low glycogen levels has shown that both a surplus and a lack of glycogen with exercise can trigger positive training adaptations. A low carbohydrate diet has also been shown to increase the ability to oxidize fat during exercise, but may impair carbohydrate utilization with high-intensity exercise.

Some athletes already periodize their carbohydrate availability for training sessions. By design or accident, many workout sessions are undertaken with reduced carbohydrate stores. Whether implementing additional ‘‘train-low’’ strategies to increase the training adaptation leads to enhanced performance in well-trained individuals remains unclear, and further research is warranted.


Questions for Discussion:

An important question is whether training with reduced glycogen stores should be exploited, and how can that be accomplished without having negative effects on the athlete’s performance?

Similar to this article by Burke and colleagues, the recent article by Volek, Noakes and Phinney (2014), “Rethinking fat as a fuel for endurance exercise,” makes a strong argument for using our largest fuel source, fat. Utilizing fat would cause a shift to fatty acids and ketones as the primary fuel for endurance athletes, which is known as keto-adaptation. There is a need to better understand what level of carbohydrate restriction is appropriate and what the exact composition of the diet should consist of to fully benefit from keto-adapation.

The review presents what may be an entirely different model of fueling athletic performance, “dietary periodization”, which includes periods of training in a low carbohydrate environment. On one hand, the review gives key recommendations for our athletes in regards to training and restoration of glycogen and fuel for performance. On the other, it asks, what might be the best training programs using carbohydrate restriction and dietary periodization?


This will be a fascinating area of future research.


Written By: Michael Reeder, D.O.

Reviewed By: Felice Beitzel, Ph.D.


Additional Reference:

Volek JS, Noakes T, Phinney SD. Rethinking fat as fuel for endurance exercise. European Journal of Sport Science, 2014

2015 Medicine of Cycling Conference

Posted on January 8, 2015 by Courtney Barnes

We are happy to announce that the 2015 Medicine of Cycling Conference will take place Aug 14-16 in Colorado Springs. We hope you will make plans to be there! Keep an eye out for more details as the dates get closer and you can find out more on our conference page. Let us know if you have any thoughts, comments or questions.

Seeking Volunteers for Core Strengthening Research Study

Posted on January 7, 2015 by Alynn Kakuk

A group of researchers are currently in need of more volunteers for their study on the effects of core strengthening on VO2max in cyclists.  Currently, there are very few studies related to core strength/core training in cyclists, so please consider helping them out!  See below for more information about the study, as well as who to contact!


Purpose: The purpose of this study is to investigate the correlation between core strengthening exercise and VO2max in elite cyclists.

Methods: We have developed an 8-week training protocol that targets core strength and VO2max. Our protocol utilizes specific core strengthening exercises and power-based cycling intervals that progress in difficulty over the 8-week period. This protocol has shown promise in a preliminary pilot study.

Inclusion criteria: Cyclists must be 18 or older; posses a license through USA Cycling or a comparable local license and demonstrate appropriate baseline fitness. Additionally, individuals must not currently participate in a core-strengthening program.

Equipment/space needed: As we are utilizing power-based data, participants must own or have regular access to a bicycle or stationary trainer with a power meter. Other necessary equipment includes a heart rate monitor and a cycling computer to download and share their data. Depending on group assignments, participants may need a 36 inch-long round foam roller and a 65cm gym ball.

What is required of participants to complete: Cyclists will be randomly assigned to one of our study groups. Depending on group, participants will be prescribed a VO2max training protocol tailored to their fitness as demonstrated in a baseline power test and/or a standardized core-strengthening program. Test will be performed to establish baseline fitness prior to the study and at 4 and 8 weeks to record performance.


Contact info:

Craig Abrams, DC

Founder/Chiropractor at CADC


Josh Friedman

Owner/Coah at ATP Race Consulting


Neil Krulewitz

Medical Student at University of New England

New Research Blog

Posted on January 1, 2015 by Alynn Kakuk

To start off the 2015 new year, we are debuting a new feature of our blog!  Every 2 weeks, we will post a summary of a cycling related journal article.  The purpose is to bring awareness to new research, as well as spark discussion about cycling medicine.  We hope you enjoy this new addition to our blog.  Here is our first post:


The Club-Level Road Cyclist: Injury, Pain, and Performance

Dahlquist M, Leisz MC, Finkelstein M. The Club-Level Road Cyclist: Injury, Pain, and Performance. Clin J Sport Med. 2014 Jun 9. [Epub ahead of print]


Article Summary:

With the increase in popularity in cycling in the United States, there is more information about types of injuries in cyclists. The authors of this study looked to examine the differences in activity levels of injured and non-injured cyclists, identify factors that influence when a cyclist seeks medical treatment, and examine biomechanical measures and their relationship to injury in an observational and prospective study of 63 experienced road cyclists. Participants reported demographic information, training information, and 8-week injury incident questionnaire. Researchers collected anthropometrics, bike fit measurements, hamstring flexibility, isometric strength, dynamic strength, and plyometric strength. The researchers found that 68.7% of participants experienced pain while cycling due to injuries with 65.1% reporting the injury duration >1 year. Of those reporting pain at enrollment, the average visual analog score (VAS) was 4.8 at the worst. The most common injuries at enrollment involved neck, shoulder, lumbar spine, and knees, which were reported due to muscle, tendon, and stress/overuse. During the 8-week prospective injury-reporting period, 39.7% of participants reported 34 injury events. Those who reported pain at initial enrollment were 48.8% likely to have an injury during this period compared to 20% of those uninjured at time of enrollment. Those that had a professional bike fit performed were more likely to have prospectively reported an injury. Flexibility, strength, and bike fit had no relation to injury. The authors concluded that greater than 2/3 of participants experienced pain >4 on a VAS, cyclists train intensely even with pain, if pain intensity >5.6 a cyclist is more likely to seek medical treatment, and factors that contribute to seeking medical care included pain levels and age.


Questions for Discussion:

  • With one of the most common injuries at enrollment being related to the lumbar spine, are cyclists performing enough core training and stabilization activities to prevent this issue?
  • Cyclists train even with pain. Are we encouraging athletes to take adequate rest and recover to improve performance?
  • What are the common attitudes and/or mental aspects of cyclists that might lead to not seeking treatment?


Written By: Alexandra Flis, MD

Reviewed by Louis Yu, MD


Cycling Safety

Posted on September 26, 2014 by Courtney Barnes

Cycling is a beautiful and fun sport.  We have to figure out a better system for safety.  Our friends are getting hit (disabled and killed) by vehicles AND our friends are hitting (disabling and killing) pedestrians.  Cyclists are doctors, lawyers, engineers, entrepreneurs, artists, researchers, executives.  This is our problem to solve.  Please blog, email, FB, tweet, and talk about it.

CME Course Materials for 2014 Medicine of Cycling Bike Fit, Emergenices & Main Conference

Posted on August 22, 2014 by mabramson

Each course has its own special landing page for handouts and links to online evaluation surveys.  They are: