Charles Stull MS RD - The dietary demands of MMA fighters; sure, they're grumpy when they diet. The Ultimate Fight Championship Performance Institute.
BIO: Mr. Stull is the Director of Nutrition at the UFC Performance Institute in Las Vegas. Charles Hu Stull joined Ultimate Fighting Championship (UFC) Performance Institute as the Performance Nutrition Manager in 2018. Prior to working at the UFCPI, Charles Stull was the sports dietitian for the UCLA Athletics program. Over the past 5+ years as a sports dietitian, Charles has worked with combat sports athletes (MMA, Muay Thai, Boxing) and athletes in professional organizations such as the NFL, LPGA, and USOPC. Charles was also a DI swimmer at American University and carries a seasoned Muay Thai career with over 15 years of competitive experience.
Charles Stull MS RD - The dietary demands of MMA fighters; sure, they're grumpy when they diet. The Ultimate Fight Championship Performance Institute.
BIO: Mr. Stull is the Director of Nutrition at the UFC Performance Institute in Las Vegas. Charles Hu Stull joined Ultimate Fighting Championship (UFC) Performance Institute as the Performance Nutrition Manager in 2018. Prior to working at the UFCPI, Charles Stull was the sports dietitian for the UCLA Athletics program. Over the past 5+ years as a sports dietitian, Charles has worked with combat sports athletes (MMA, Muay Thai, Boxing) and athletes in professional organizations such as the NFL, LPGA, and USOPC. Charles was also a DI swimmer at American University and carries a seasoned Muay Thai career with over 15 years of competitive experience.
Thank you everyone. First off, I want to big thank you to Jose and the ISACEN for continuing to support the UFC, the UFC PI, in its research and innovation initiatives. I'm also kind of fortunate to have had Sean and Eric to discuss biochemical assays as well as energy expenditure. My presentation today will pretty much be sharing some of the lessons learned in managing energy availability and weight class sports. So a perfect segue. Combat sports athletes have to overcome some pretty unique challenges of weight making and also maximizing performance adaptations, oftentimes in the state of low energy or negative energy balance, and in this webinar we'll really be focusing on the nutrition concerns associated with this low energy balance. We'll also cover some of the definitions within the context of energy balance, factors that may modulate the effects of low energy balance and, of course, the IOC's Reds Health Conceptual Model within the context of combat sports. And really this is to better empower dietitians, nutritionists working in the space to better identify, manage and correct low energy availability symptoms. So before we can even dive into low energy availability, we have to know what energy availability is and, simply put, it's the dietary energy leftover and available for optimum function of the body systems, after accounting for energy expenditure from exercise and the energy availability equation is simply the dietary energy intake minus exercise energy expenditure divided by fat free mass and that's the calories per day. Low energy availability is any mismatch between dietary energy intake and energy expenditure and exercise that leaves the body's total energy needs unmet and this means there is an inadequate amount of energy to support the functions required by the body to maintain optimal health and performance. And the physiological effects of low EA are really on a sliding scale and LEA initially can present as benign but modulating factors can really tip the scales, resulting in physiological consequences. Adaptable low energy availability is exposure to a reduction in energy availability with benign effects. And the effects of adaptable LEA can be mild or even very easily reversible once energy mismatch is resolved. So let's say you, once you've completed a fight camp and you kind of return back to baseline energy intake, adaptable LEA is actually ideal when we're programming a sustainable and repeatable weight descent. Athletes may even exhibit acute health and performance benefits, particularly in our sport where power to weight ratio is an important aspect of performance. But keep in mind that adaptable LEA is typically quite short term within an athlete's preparation cycle. So let's say early or at the very least late fight camp.
Speaker 1:Issues really start to arise when we have problematic LEA, as the name suggests, and this is when the duration or the severe, the severity of the calorie restriction resists results in persistent disruptions to a variety of physiological systems, and really this, this essentially means you have a maladaptive response. The disruption to these various physiological systems will be discussed a little later in the presentation. But things that can modulate, these are literally the modulating factors, and they're actually quite an array of modulating factors that can include athlete characteristics, environmental and behavior, athlete behaviors, and these may either amplify or simply attenuate the effects of LEA. Some of these other examples can include athletes, gender, age and genetics, but I'll go over those in just a little bit. So relative energy deficiency in sports, or reds, is basically a syndrome of impaired physiological or psychological functioning experienced by female and male athletes. Reds is caused by exposure to problematic LEA and the detrimental physiological outcomes of reds can be individually and synergistically lead to impaired well being, increased injury risk and, of course, decreased health and performance. So just to go into those modulating factors, which are those factors that may amplify, accelerate or attenuate the development of problematic LEA, the big one is literally the threshold, the threshold at which there is a mismatch in energy and as a whole, when we're talking about optimal energy availability. For female athletes in particular, it's actually about 45 kcal per kilo of fat-free mass per day. However, a more commonly used threshold by us is at 30 kcal per kilo of fat-free mass per day. If there's any takeaway from this presentation, that 30 kcal per kilo roughly equates to the average resting metabolic rate, which ties in quite nicely with some of Eric's equations. The presentation prior. This historical threshold was established because studies showed that physiological consequences really started to manifest when EA was lower than 30. I will point out, though, that despite this common cutoff, it does not predict amenorrhea in all female athletes, which is why that 45 kcal per kilo kind of comes into fruition.
Speaker 1:This is a pretty problematic area within the sporting community that I work with. Low carbohydrate diets really have demonstrated that, even when they're in calorie neutral, they have increased markers of bone reabsorption, increased inflammatory cytokines that may impact immunity, and increases in hepsidon, which is the inflammation-induced hormone that blocks iron absorption. There is a lot of nutrition misinformation right now. That's kind of proliferating within social media. Jose is very good at pointing out all these clowns right here. I just wanted to highlight them. Our combat sports athletes can oftentimes fall victim to a lot of the sensationalism around keto and carnivore diets, and they may even adopt a low carbohydrate diet to artificially elicit weight loss during a weight descent, just to hit certain thresholds and weight loss goals. In addition, I'd say a big issue that we're coming across, and we're continually having to reeducate our athletes, is the misconceptions around fat oxidation and weight loss. That really drives athletes towards these low and unsustainable low carbohydrate diets.
Speaker 1:Duration, Needless to say, the duration of which the low energy availability can really modulate those physiological effects, the thresholds and evidence around it is still a growing area of research. However, short-term LEA is really classified as a few days to weeks, so let's say, light fight camp or even fight week. Middle term is classified as a couple months and long term is months to years. Naturally, with the increase in the duration LEA, there's an increased risk of problems arising. Of course, as I mentioned earlier, there certainly are gender differences in reds. As 30K KK per kilo is kind of our threshold, females need that 45. I will point out, though, that males tend to experience reds related symptoms at a lower energy availability of between 9 to 25 KK per kilo. There is evidence that males can sustain lower energy availability before physiological as well as the psychological disturbances manifest. This is definitely something that we see within our athlete cohort that the males definitely seem to be able to buffer and withstand low energy availability before any issues start to manifest.
Speaker 1:The next kind of component is really looking at the practical side and using the IOC REDS conceptual model as a framework. So the IOC REDS conceptual model really provides practitioners nutritionist, dietitians with a roadmap of the physiological consequences of LEA and really helps practitioners identify the domains of dietary influence. And actually I think it's quite empowering, if anything, because it allows us to make actionable changes to an athlete's health and performance trajectory. Given that combat sports athletes commonly undergo periods of low energy availability, really want to stress that care must be taken to utilize and as well as track the objective as well as subjective markers of REDS. At the UFC PI we have quite a unique perspective on the demands and consequences of weight making. Our athletes utilize us for an array of in-person, remote as well as event support services. To that end, we are often tasked with managing some of the most challenging cases. Often times they have persistent REDS physiological dysfunction and I'm going to kind of break it down in some of the following examples, but it's all kind of synthesized in this diagram of this PowerPoint.
Speaker 1:So first off, looking at reproductive function combat sports athletes, as they undergo prolonged low energy availability, they may exhibit physiological consequences to their reproductive systems. Our male combat sports athletes may experience reductions in testosterone, sperm abnormalities, erectile dysfunction and reductions in libido. Practitioners can really monitor subjective signs and symptoms of reproductive impairment by tracking changes in male libido, especially when biochemical assays are not always available. Our female combat sports athletes may exhibit alterations in luteinizing hormone concentrations, reduced estrogen and progesterone, reduced testosterone and primary or even secondary amenorrhea. One of the challenges we've come across in terms of monitoring our female athletes is the common use of hormonal contraceptives to create some form of menstrual regularity so they can essentially plan and compensate for any water attention they may experience leading up to a fight, which oftentimes masks some of the menstrual irregularity.
Speaker 1:In terms of bone health, our combat sports athletes, particularly our females, may exhibit longitudinal loss of bone mineral density and or lower than expected bone accural during development. In addition to lower bone mineral density, z scores, impaired bone strength and thus increased risk of bone injuries and stress. Fractures can also manifest, obviously, due to the collision nature of combat sports, especially those high velocity striking disciplines like Muay Thai and my main, kickboxing, a lack of bone resiliency can really accentuate injury risk and time away from sport. Care must really be taken to monitor micronutrient intake as well as reduce the severity of LEA when possible, especially for athletes with a high fat frame mass relative to their division, because those athletes in particular will tend to avoid additional loading and resistance training, which is by default protective around their bone health. In addition, athletes already prone to LEA may gravitate towards diets that are lower in dairy, further reducing dietary intake of NM&D in calcium. So, when able, utilize a DEXA to both screen but also monitor changes in bone mineral density when able. Here's just a nice example of an athlete that we had that exhibited osteopenia.
Speaker 1:Gastrointestinal symptoms such as abdominal pain, cramping, bloating or even alterations in bowel movements can be a consequence of problematic low energy availability Comet sports athletes often adopt dietary patterns that lack variety and completely omit certain food groups, and this reduction in food diversity the avoidance of refined carbohydrates, red meat, dairy products perpetuates itself because their reintroduction can oftentimes lead to GI discomfort. Another challenge with athletes, especially following even a weight descent that's systemized is the lack of consistent bowel movements, and this is simply because of a lack of total food mass, as well as omitting whole grains, which contribute to fecal mass and reduce gastrointestinal transit times. So really, practitioners should really encourage the strategic integration of a variety of food groups through the entirety of a combat athletes preparation cycle. Problematic LEA can also lead to reductions in T3, as John mentioned, and this manifests in reductions in their resting metabolic rate, as well as increased cortisol and reduced leptin. Even able practitioners can utilize indirect calorimetry to assess an athlete's resting metabolic rate. The benefit of RMR is it can be easily integrated as part of an athlete's anthropometric check-in. Biochemical tests to screen for T3 thyroid function are also valuable tools, as Sean also mentioned.
Speaker 1:Although cortisol is a valuable physiological marker from our athletes, its practicality within combat sports is somewhat limited by the frequency of testing needed to monitor circadian trends and to really make actionable lifestyle and training load changes due to its cyclical nature. So RED's hematological profiles can also include low iron status and increased epsidon, which lowers iron absorption, lower hemoglobin concentrations and hemoglobin mass. Iron absorption is impaired by hepsidon, which is released in response to inflammation, such as exercise-induced inflammation. Combat sports athletes, and particularly MMA athletes adopt multiple training sessions per day, in addition to supplemental aerobic exercise, to increase their energy expenditure. The frequency of training, as well as the adoption of red meat phobic dietary patterns, can just further inhibit heme-rich food sources and thus inhibiting their absorption. So a real challenge for practitioners in this space is really screening for our athletes' health status in this area, but also programming these iron-rich foods as well as a supplementation strategy around optimal windows of iron absorption, which is a whole topic in and of itself. Our athletes as well, and just as a nice little case example just highlighting some of the very low ferritin levels that our athletes have and this is, of course, done with an athlete that did not have any systemic inflammation, wasn't in a high training load environment and also didn't have illness.
Speaker 1:Urinary incontinence is quite commonly reported within our athlete population too, and that's mostly actually induced by nocturnal urination frequency. Daytime fluid inadequacy, particularly around training, results in a compensation of fluid intake, and especially when our athletes are preparing for fights, which are often at night and they're trying to train at the same time that they'd be competing, these late night training sessions really delay the fluid intake closer to sleep and ingesting a large bolus of fluid without inadequate sodium intake and reduce fluid retention and increase urine output. So a proactive hydration strategy before, during and immediately after training can help reduce that urination frequency. During the night Reds can also result in reductions in fasting glucose, insulin levels can elevate total cholesterol and elevate LDL cholesterol. As I mentioned earlier, carbohydrate phobia can really exacerbate maladaptive glucose and lipid metabolism.
Speaker 1:Practitioners should always monitor athletes' carbohydrate intake. Even in a calorie-restrictive sport such as MMA. We don't like ever programming less than 3 grams per kilo per day of carbohydrates, even on an aggressive weight descent. A very useful tool that we have is utilizing indirect calorimetry, as it really shows the respiratory quotient, aka substrate utilization. As you can see right here in this example, this very carbohydrate-phobic diet had a respiratory quotient between 0.7 and 0.8. That really highlights an over-reliance on fat energy substrate and a low energy balance. Of course, depression, exercise-induced dependency or addiction and eating disorders may also be present in combat sports. Really for the mental health Reds outcomes, we really stress that it should be part of an interdisciplinary team approach under the supervision of a physician, a psychologist as well as a registered dietitian.
Speaker 1:Neurocognitive and physiological consequences to problematic LEA includes reduced or impaired memory, reductions in decision-making, spatial awareness, aka getting hit, more poor cognitive flexibility and reductions in executive function. What I'd like to point out here with regards to the sleep disruptions, the duration, the latency as well as the quality of reported symptoms Really those sleep disturbances can develop from problematic LEA due to sleep fragmentation, which in turn may actually exacerbate other Reds domains. As we know, there is a relationship around sleep, total sleep and sex hormones, especially in males. Even the cardiovascular function EKGs can also. Abnormalities can also result from problematic LEA.
Speaker 1:But something that's perhaps a little bit more practical for our practice is those maladaptive adaptations to the autonomic nervous system balance. This is quite nicely highlighted in this snapshot of an eight-week preparation cycle where we had an athlete that initially was doing great, was on a energy balance that was sustainable, but sustained an injury that prevented us from basically we became behind schedule. The energy had to enter the last three weeks of their fight camp with a low energy availability and it definitely took a toll on HRV. In addition, combat sports athletes may see significant reductions in fat-free mass during early, late and fight week. When able, we'd like our athletes to engage in resistance training in the off-camp phases, definitely to a cure fat-free mass, as long as it's part of an interdisciplinary performance improvement plan and the athlete can actually afford to put on the fat-free mass. I will say that athletes that continue to adhere to those dietary strategies carb phobia, energy mismatch have reduced rates of muscle protein synthesis and can almost never hit their fat-free mass goals.
Speaker 1:The last two, basically growth and development, is really not an area that we have to be too concerned with, as our athletes are usually adults, have already finished their growth and development by the time they reach us. But in particular for practitioners who are dealing with youth athletes, really an emphasis on prioritizing energy availability primarily around growth and development and really the education not only has to occur with the athletes but also the guardians, training staff in order to ensure that sustainable weight making strategies are employed. And, last but not least, immunity. This is perhaps one of the more hot topics within our domain right now and this is an area that we're definitely investing more resources into figuring out how we can reduce the frequency of. But low energy availability definitely increases infection, illness susceptibility and practitioners, particularly during the weight descent early and late fight camp practitioners really have to prioritize sustainable weight descents and also evidence-based immune support supplementation strategies as well as dietary approaches and there definitely has been a proliferation amount of staff related infections that have hampered fights or even complicated acute weight cuts.
Speaker 1:So, long story short, in conclusion, hope this was able to just kind of shed some light into the challenges we have with balancing weight making but also energy availability within our athlete population and, if anything, hopefully practitioners, nutritionists, will be able to see a more comfortable understanding the modulating factors of LEA as well as those physiological domains that they can really target in their practice. If anyone has any interest in reaching out collaborating around this area, as it's a growing component of it's a growing area of research, this is my contact right here. I'm pretty active on social media as well and I hope you'll be OK. Hmm, what's that? I'm home.