Archive for the ‘Safety Studies’ Category

In my ongoing effort to highlight safety studies addressing combative sports, a recent study was published in the Journal of Physical Medicine Science studying dehydration and skeletal muscle damage in elite wrestlers.

The study involved seventy-two elite wrestlers who participated in the Turkish Wrestling Championship and revealed that dehydrated wrestlers suffered from higher level of skeletal muscle damage than wrestlers who were not dehydrated.  The authors provided the following summary:

In summary, fast and/or higher levels of weight loss before a competition produced differences in wrestlers’ hydration indicator levels. Damage in skeletal muscles of the dehydrated wrestlers was greater than in those hydrated, but no difference was found in the inflammation levels of the groups. If it is necessary to lose weight before a competition, athletes should do it in a way to achieve a gradual and extended weight loss over a period of time depending on the weight loss targeted. In addition, while athletes are losing weight, they should keep levels of hydration and skeletal muscle damage indicators within their reference ranges through ergogenic aids. Thus, ergogenic aids will play a mediator role for wrestlers wishing to demonstrate maximum performance and to lead a healthy life.

This serves as yet another reminder to regulators that allowing rapid extreme weight cuts prior to competition and the dehydration that accompanies this practice is inconsistent with looking after fighter welfare, a central tenet of the mission statement of combat sports Athletic Commissions.

The full article can be accessed here Dehydration, skeletal muscle damage in Wrestlers

and below is the article’s abstract –

Abstract. [Purpose] The present study aimed to identify weight-loss and hydration levels before competitions among elite wrestlers and determine the skeletal muscle damage and inflammation levels after dehydration. [Subjects] Seventy-two elite wrestlers who participated in the Turkish Wrestling Championship. [Methods] With the help of specialists, 5 cc of blood were drawn from the forearm veins of the wrestlers. Laboratory analyses of Na+, BUN, Glucose, CK, LDH, AST, ALT, C-RP levels were performed. Using a mathematical formula for hydration the POsm levels of the athletes were calculated. [Results] The wrestlers were divided into two groups based on hydration status. There were significant correlations between hydration indicators of Na+, BUN and PBWL values. There were significant differences between AST, LDH, CK values and skeletal muscle damage indicators of the two groups, but there were no significant differences between the inflammation levels and C-RP values of the groups. [Conclusion] No differences existed in inflammation levels among the wrestlers, although dehydrated wrestlers suffered from higher level of skeletal muscle damage than wrestlers who were not dehydrated.

screenshot headgear

Martial Arts enthusiast, Physicist and author Jason Thalken has recently obtained a patent for a headgear design that he hopes can reduce head trauma and the incidence of Chronic Traumatic Encephalopathy in contact sports.

In en effort to bring attention to this patent Thalken has published the full text of his patent to Researchgate and is available here.

Headgrear for Reducing Head Trauma Patent Material

Thalken Tweets

I won’t pretend to have a physics or engineering background capable of dissecting the potential efficacy of this product but if other physicists agree that Thalken’s designs hold potential the combat sports and contact sports world should help him secure the funding he needs to get this product off the ground.


An important study was recently published in the open access journal, PLOS ONE, analyzing the relationship between the severity of traumatic brain injury and anabolic steroid use.

In the Study, titled “Chronic Exposure to Androgenic-Anabolic Steroids Exacerbates Axonal Injury and Microgliosis in the CHIMERA Mouse Model of Repetitive Concussion” the authors noted that in about 20% of known Chronic Traumatic Encephalopathy (CTE) cases the subjects had a history of substance use including androgenic-anabolic steroids.

The authors questioned whether there was a connection between anabolic steroid use and severity of brain injury and conducted a study involving mice.  Some of the mice received a cocktail of three anabolic steroids (testosterone, nandrolone and 17α-methyltestosterone) and were later exposed to two incidents causing traumatic brain injury.

The mice exposed to steroids exhibited significantly exacerbated axonal injury and microgliosis leading the authors to conclude that anabolic steroid use “can alter neuronal and innate immune responses to concussive TBI

The full study is available by subscription and the abstract can be found here and is reproduced below –


Concussion is a serious health concern. Concussion in athletes is of particular interest with respect to the relationship of concussion exposure to risk of chronic traumatic encephalopathy (CTE), a neurodegenerative condition associated with altered cognitive and psychiatric functions and profound tauopathy. However, much remains to be learned about factors other than cumulative exposure that could influence concussion pathogenesis. Approximately 20% of CTE cases report a history of substance use including androgenic-anabolic steroids (AAS). How acute, chronic, or historical AAS use may affect the vulnerability of the brain to concussion is unknown. We therefore tested whether antecedent AAS exposure in young, male C57Bl/6 mice affects acute behavioral and neuropathological responses to mild traumatic brain injury (TBI) induced with the CHIMERA (Closed Head Impact Model of Engineered Rotational Acceleration) platform. Male C57Bl/6 mice received either vehicle or a cocktail of three AAS (testosterone, nandrolone and 17α-methyltestosterone) from 8–16 weeks of age. At the end of the 7th week of treatment, mice underwent two closed-head TBI or sham procedures spaced 24 h apart using CHIMERA. Post-repetitive TBI (rTBI) behavior was assessed for 7 d followed by tissue collection. AAS treatment induced the expected physiological changes including increased body weight, testicular atrophy, aggression and downregulation of brain 5-HT1B receptor expression. rTBI induced behavioral deficits, widespread axonal injury and white matter microgliosis. While AAS treatment did not worsen post-rTBI behavioral changes, AAS-treated mice exhibited significantly exacerbated axonal injury and microgliosis, indicating that AAS exposure can alter neuronal and innate immune responses to concussive TBI.

Update – This article has been republished at where a forum member helpfully points to this 2013 study which concludes that long-term high-dose anabolic-androgenic steroids exposure may cause cognitive deficits, notably in visuospatial memory even without exposure to head trauma.

NoteThe below findings likely exclude concussions which appear to be “significantly underreported” with the authors noting that 40% of contests end in KO/TKO and concussions are likely in many of these bouts.  In other words, the study finds there is a 39% reported injury rate in kickboxing bouts in addition to the likely brain trauma that comes from bouts ending in KO/TKO


In the latest safety study addressing combat sports, professional and amateur kickboxing records were reviewed revealing 39% injury rate for competitors.

In the recent study, titled Injuries to Professional and Amateur Kickboxing Contestants, published this month in the Orthopaedic Journal of Sports Medicine, the authors obtained and reviewed data describing fight outcomes and injuries sustained during professional and amateur kickboxing contests over a 15-year period from the official records of the Nevada Athletic Commission.

The records revealed an overall injury incidence rate of 390.1 injuries per fighter per 1000 contests.

The data further showed that professional fighters were 2.5 times more likely to get injured compared with amateurs.

The most commonly injured anatomic regions were the head (57.8%) and lower extremity (26.1%), while the most common types of injury were laceration (70.6%) and fracture (20.6%).

Study Table 1

The full study can be found here – Injuries to Professional and Amateur Kickboxing Contestants

Update December 2, 2015 – The full study can be found here – CTE in Amateur Athletes Study 

The Mayo Clinic has uploaded the following useful video summarizing this study –



Chronic Traumatic Encephalopathy (CTE), a brain disorder related to repetative traumatic brain injury is perhaps one of the most troubling risks associated with the world of contact sports.  As the medical industry better understands this progressive disease the link between prolonged exposure to sub concussive blows and the disease becomes ever clearer.  To this end a study was recently published in the journal Acta Neuropathologica showing just how strong the link is.

In the study, titled “Chronic traumatic encephalopathy pathology in a neurodegenerative disorders brain bank” the authors accessed a brain bank and processed samples for tau immunohistochemistry.  Medical records were cross referenced to determine if the samples came from individuals with a history of contact sports participation.  The study revealed as follows

  • 21 of 66 former athletes had cortical tau pathology consistent with CTE
  • CTE pathology was not detected in 198 individuals without exposure to contact sports, including 33 individuals with documented single-incident TBI sustained from falls, motor vehicle accidents, domestic violence, or assaults
  • CTE pathology was only detected in individuals with documented participation in contact sports

The authors conclude that “exposure to contact sports was the greatest risk factor for CTE pathology”.

The study’s abstract can be found here .

There are many documented cases of injury in MMA due to the profound dehydration that comes with rapid extreme weight cutting.  Perhaps the most dangerous risk is that of increased brain trauma and death that comes from being exposed to strikes while not being fully hydrated.  As this industry wide practice is becoming better recognized by the public more calls for regulatory reform are being made.

The latest comes from the British Journal of Sports Medicine who, this month, published an article reviewing local rapid extreme weight cut practices and noted “an alarming culture of weight making.”.

The practices from the athletes surveyed revealed as follows –

  • In total, 67% of athletes engaged in a previously unreported practice of ‘waterloading’, whereby athletes reduce sodium intake and overdrink water (eg, 20–23 Lover 3 days), in the belief it will trigger a ‘flushing mode’ to induce excessive urine production.
  • Several athletes (17%) reported the use of solutions to increase sweating by increasing circulation
    eg, Sweet sweat) or by blocking the pores (eg, Albolene).
  • Athletes (37%) consumed prescription and over-the-counter diuretics and
  • 13% utilized intravenous lines (1 self-administered, 3 administered by a physician) and glycerol to encourage rehydration post-weigh-in.
  • In total, 73% of athletes consumed nutritional supplements during weight-cutting, though 61% did not know whether supplements were tested for banned substances
  • One hundred per cent of the MMA athletes engaged in complete fasting or low carbohydrate diets in the final 3–5 days prior to weigh-in thereby promoting ‘relative energy deficiency’
  • Only 20% of athletes obtained dietary advice from qualified sports dietitians/nutritionists, with the majority of advice provided from coaches, peers and internet sources.

The physicians called for regulatory reform for these practices, including the practice I have been most vocal about, namely adding a hydration requirement for athletes when they make weight.  Yes this will drastically alter the current landscape of weight classes athletes are used to competing in but it will restore sanity to the reason weight classes exist in the first place – protection of the fighters,

Specifically the  BJSM requests that regulators schedule “weigh-ins 24 h or less before competition alongside minimal hydration acceptable limits.

The full study can be found here – Alarming Weight Cutting Practices in MMA

In my ongoing effort to highlight safety studies addressing combative sports, a thesis paper was recently published by the University of Ottawa’s Interdisciplinary School of Health Sciences reviewing factors associated with head trauma in professional MMA.

The author analysed data from Fightmetric reviewing 7,134 rounds in the UFC, WEC and Strikeforce from 2004 – 2014.  The study noted several factors linked to higher rate of concussion, two of which were fighter age (older fighters being more susceptible to concussion) and time between bouts (with a shorter period between bouts being linked to a higher concussive rate).  On these points the author notes as follows –

Increasing age is positively associated with head trauma (p<.05; OR 3.2). Prolonging the time period in between fights is protective against head trauma (p<.05; OR 0.81)…

…the age at which a fighter steps into the octagon is associated with head trauma. The older the fighter, the more likely he or she is to suffer a concussion…

Moreover, the number of months in between a combatants fights is detrimental to the discussion of concussion in MMA. The more time, in months, the fighters spend resting or training prior to their next fight the less chance they will suffer a concussion during the fight. Strong evidence is lacking to identify an appropriate time-frame that fighters should adhere to before initiating training for their next fight..

The full study can be found here – Factors Associated With Head Trauma Among Professional Mixed Martial Arts Athletes

Given that CTE is being linked to duration and severity of contact and further that the KO rate by punches in MMA increased tenfold after gloves with conventional wraps became the norm in the sport, should MMA and other striking sport athletes use ‘padded’ hand wraps to reduce brain trauma while sparring?  An article published this week in the International Journal of Kinesiology and Sports Science suggests so.

In the recent article, titled “The Influence of a Padded Hand Wrap on Punching Force in Elite and Untrained Punchers” the authors had 14 trained fighters and 24 untrained individuals punch at maximum power with gloves and conventional wraps and then again with “an additional 1.2cm thick cylinder 4g foam-like pad placed over the knuckles”.  The tests revealed that the additional padding reduced punching force by 8.9% for the untrained individuals and 12.6% for the trained fighters.

Graphic from padded punching power study

The authors conclude that “Practitioners should consider utilizing hand-padding strategies such as this during practice/sparring as the reduction in punching force will likely have important long-term health implications for both the puncher and the person absorbing the punch.“.

The full study can be found here – The Influence of a Padded Hand Wrap on Punching Force

Whether or not adding padding to training hand wraps helps address TBI in combat sports all athletes would be wise to remember that the accumulation of sub concussive trauma likely leads to CTE and methods which respect long term brain health should be first and foremost in any training program.

In the latest article addressing injury issues in combative sports, a study was published last month in the Journal of Neurotrauma studying cognitive impairment from boxing.

The study, titled Chronic Effects of Boxing: DTI and Cognitive Findings, used Magnetic Resonance Imaging and Diffusion Tensor Imaging to study brain trauma among 10 boxers (9 active and 2 retired) and 9 other participants not involved in combative sports.

Unsurprisingly the study noted cognitive issues among the boxers and, consistent with other recent studies, pointed to the number of years involved in the sport, as an important factor leading to long term impairment.

To this point the study concluded “Years of boxing had the most consistent, negative correlations with FA, ranging from -0.65 for the right ventral striatum to -0.92 for the right cerebral peduncle. Years of boxing was negatively related to the number of words consistently recalled over trials (r=-.74, p=0.02), delayed recall (r=-0.83, p=0.003), and serial RT, (r=.66, p=0.05).”

The full abstract can be found here

We used magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) to evaluate the effects of boxing on brain structure and cognition in 10 boxers (8 retired, 2 active) (mean age=45.7 years, SD=9.71) and nine participants (mean age=43.44, SD=9.11) in non-combative sports. Evans Index (maximum width of the anterior horns of the lateral ventricles/maximal width of the internal diameter of the skull) was significantly larger in the boxers, (F=4.52, p=0.050; Cohen’s f=0.531). Word list recall was impaired in the boxers ((F1,14)=10.70, p=0.006, f=0.84)) whereas implicit memory measured by faster reaction time (RT) to a repeating sequence of numbers than to a random sequence was preserved t=2.52, p<0.04. Fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) measured by tractography did not significantly differ between the groups. However, DTI metrics were significantly correlated with declarative memory (e.g., left ventral striatum ADC with delayed recall, r=-0.74, p=0.02) and with RT to the repeating number sequence, (r=0.70, p=0.04) in the boxers. Years of boxing had the most consistent, negative correlations with FA, ranging from -0.65 for the right ventral striatum to -0.92 for the right cerebral peduncle. Years of boxing was negatively related to the number of words consistently recalled over trials (r=-.74, p=0.02), delayed recall (r=-0.83, p=0.003), and serial RT, (r=.66, p=0.05). We conclude that microstructural integrity of white matter tracts is related to declarative memory and response speed in boxers and to the extent of boxing exposure. Implications for chronic traumatic encephalopathy are discussed.

One of the latest safety studies addressing combat sports, published last month in the journal Australasian Epidemiologist, the author compiled data from a total of 47 observational studies addressing injuries in combat sports.  Specifically the author looked for the injury incidence rate, injury patterns and injury severity rates in 6 different sports, namely boxing, judo, karate, kickboxing, mixed martial arts, and taekwondo.

The study found that sports with a striking element had the greatest injury rate with MMA leading the pack followed by boxing and the other striking sports and with Judo having the lowest injury rate of the group.

In terms of injury patterns the study found that “The head and neck was the most frequently injured anatomical region in boxing (84%), karate (74%), mixed martial arts (64%), and kickboxing (55%); whereas the lower limb and upper limb were the most frequently anatomical regions in taekwondo (51%) and judo (47%), respectively.

Lastly, in terms of injury severity the study was lacking data on boxing, MMA and kickboxing.  Of the remainign sports the study concluded that “the proportion of moderate to severe injuries (i.e. injuries resulting in more than one week of time lost from play) was 32% in taekwondo. 15% in karate. and 7% in judo.

I should mention that a recent study published addressing MMA and boxing injury severity rates noting that while MMA had a greater overall injury rate than boxing, boxing injuries tended to be more severe.

The full study can be found here – Epidemiology of injuries in full-contact combat sports

The study included the following helpful visual charts –

Figure 1 Figure 2

Figure 3

Figure 4