In combat sports, a larger and heavier athlete is expected to have a natural strength and power advantage over a smaller counterpart, as they have the potential to generate more force through their size. Weight classes were therefore introduced so that athletes fight similar weight opponents with the aim to remove these advantages and level the field. However, many athletes choose to fight at lower weight classes than their walking weight with the aim to gain back some of this size/strength advantage. Many undergo weight-loss, typically through extreme caloric restriction and, in the final stages, rapid weight loss (RWL), typically by adopting weight cutting techniques including reducing total body water, stored glycogen (carbohydrates), and gut contents (for more information on weight cutting, see blog here). In this blog we focus on our current understanding of the potential impacts of severe caloric restriction, physiologically and psychologically, and what might need to be considered post fight to ensure the athlete recovers both in terms of health and performance for the long term. Note … it is possible to make weight safely, but it is a topic that shouldn’t be taken lightly! This article is focussed on the potential ‘negatives’ and implications beyond the competition, so that readers are aware and can take these on board.
Low Energy Availability and RED-S
Weight-loss achieved through restricting energy intake (calorie intake), coupled with high training loads, can result in low energy availability (LEA) (Wasserfurth et al, 2020). Energy availability (EA) describes the amount of energy (calories) we have left over after intentionally expending energy through exercise (Wasserfurth et al, 2020). It is the energy the body has available for survival and health, i.e. to ‘run’ every bodily function from thinking and breathing, to digestion, reproduction, and the immune system. If we do not consume enough calories to meet these needs, energy availability may be insufficient (i.e. we have a situation of LEA) and Relative Energy Deficiency Syndrome (RED-S) may develop (Mountjoy et al, 2018). Essentially, the body prioritises the energy the energy that is available for the maintenance of functions most vital to survival (e.g. breathing) at the expense of others (e.g. hormone production, digestive system). Although from a health perspective we ‘ideally’ would not do this, an athlete may intentionally enter a state of LEA in order to achieve a required rate of weight loss (Wasserfurth et al, 2020). LEA can also occur unintentionally during periods of intense or increased training load where nutritional intake has not been adjusted accordingly to meet these increased energy requirements (Wasserfurth et al, 2020).
RED-S can have a number of adverse physiological as well as psychological consequences, many of which may affect performance directly or indirectly (Burke et al, 2018; Dipla, et al 2020). Of particular interest in the context of an athletic career and health are the potential long-term physical and mental health implications of LEA and RED-S. This may be particularly relevant to weight class athletes who are frequently fluctuating in and out of LEA pre- and post-competition.
It has been observed that RED-S results in a dampening of hormone production, particularly sex hormones such as testosterone, oestrogen, and progesterone (Dipla et al, 2020). This is likely because our reproductive system is expendable for basic survival (and reducing the capacity to bear offspring in a time of ‘famine’ may have a survival advantage). As testosterone plays a role in training adaptation (increased muscle mass, muscle protein synthesis, and bone density), we might hypothesise that a dramatic fall in production may inhibit our athlete from recovering adequately between training sessions, as well as adapting to their training (becoming fitter, faster, and stronger) (Bennell, Brukner, & Malcom 1996). This has the potential to inhibit them from reaching their full potential long term and/or increase injury susceptibility (Bennell, Brukner, & Malcom 1996).
The risk of RED-S leading to impaired bone health and loss of bone density, as well as impaired immunity, can have detrimental effects on the overall health and performance of the athlete, especially if repeated throughout their career (Dipla et al, 2020. Bennell, Brukner, & Malcom 1996). Remaining in this state for extended periods may increase the risk of bone fracture during competition, as well as infection and respiratory illness (Dipla et al, 2020. Mountjoy et al, 2018). Bone fractures, although typically repairable, may elongate the recovery period and become irreparable after repeated cases, consequently effecting the athlete’s long-term performance. Also, if the athlete remains in LEA /RED-S during the recovery period, the body will likely not have adequate energy to effectively repair the injury, extending the period in which the athlete is recovering and potentially preventing them from being well enough to train/compete (Mountjoy et al, 2018).
Post Competition Feed Factors
During weight-loss phase, the need to restrict calories and strictly monitor food intake can also have a negative effect on an athlete’s overall perception of food and the role it plays in our lives (both socially and nutritionally). Research suggests the methods athletes use to restrict calories (commonly cutting out carbs, fats, ‘unhealthy’ sugars, and only eating ‘clean’) can promote the demonisation of certain food groups and disordered eating (Burke et al, 2018. Dipla et al, 1996. Meule, 2020). Additionally, they may begin to view food as ‘good’ and ‘bad’. The restricted ‘bad’ foods (typically high sugar and calorie dense foods) may automatically become more appealing due to our typical human nature to crave what we restrict (Meule, 2020). One study found that 10-20% wrestlers feel unable to control eating patterns while undergoing RWL, and this number increases to 30-40% post-competition (Steen and Kelly, 1990. Franchini et al, 2012). The increase observed post-competition is important, as it suggests when the restriction subsides, control over food intake also falls, which may increase the probability of eating disorders developing (Franchini et al, 2012).
Along with the disordered perception and excessive restriction of food, research suggests disrupted hormonal regulation may contribute to the drive to eat excessively post competition (Strohacker et al, 2013. Triantafyllou et al, 2016). The low levels of body fat achieved through severe weight loss and calorie restriction may lead to less of the hormone leptin being secreted into the blood, while simultaneously elevating ghrelin concentrations (Strohacker et al, 2013). Leptin is responsible for us feeling full after we eat, while ghrelin governs hunger by increasing hunger cues to promote us to eat (Strohacker et al, 2013). Decreased levels of circulating leptin may therefore lead to an increase in appetite and lack of satiety cues, while the elevated ghrelin levels further stimulate feelings of hunger, potentially leading to overeating (Strohacker et al, 2013. Triantafyllou et al, 2016). Once competition is over and the athlete no longer has the external weight making pressure to restrict calorie intake, this hormonal milieu may further contribute to the desire to eat and therefore excess calorie consumption may drastically increase.
If excess weight gains occurs as a result of these disordered eating behaviours, they may need to enter into more extreme weight loss measures to make weight for the next competition. Successfully making weight may become more difficult, and excessive caloric restriction may once again be adopted in order to shed the extra fat, potentially entering the athlete back into a period of RED-S and exacerbating all the physiological and psychological conditions discussed in first section.
It is important to note that some weight gain (particularly to walking weight) is usually necessary post-competition as the weight the athlete has aimed to make is typically below the walking weight that supports optimal health and performance for that individual. The issue becomes when weight gain extends to or is achieved in a way that compromises physical or mental health, and performance.
Post Competition: what ‘should’ we do?
Everything discussed so far highlights the importance of adequate post-competition nutrition that works with the athlete to provide them with the nutrients needed in appropriate quantities to promote not only physical health and recovery, but also mental well-being. It also highlights the importance of selecting a weight class that is appropriate for the athlete’s natural body size to avoid extreme and depleting weight loss (that may compromise performance simply through loss of muscle and sub-optimal training and recovery in the lead up to competition). Unfortunately, there is very little research and literature regarding the optimal nutritional approach post-competition to promote health and mental well-being in athletes. We develop strategies based on physiological need and behaviour change coaching, involving mental health medical professionals where needed. By employing adequate post-competition nutrition, we are acting within the interest of the athlete overall health, while also ensuring they can sustain their performance throughout their career, long-term.
To minimise the effects of over-nutrition after a period of under-nutrition, assuming depletion has not been so extreme as to immediately complement health, ‘reverse dieting’ can be employed. This involves gradually increasing calories as a percentage of calorie intake prior to competition (Mehanna, Moledina, and Travis, 2018). Along with increased calorie intake, adequate supplementation of electrolytes and micronutrients (vitamins and minerals) may be necessary to replenish those lost during the weight-loss period (Mehanna, Moledina, and Travis, 2018). Restricting whole food groups and certain foods may have resulted in micronutrient deficiency, and the knock-on effects of disrupted hormonal regulation may have resulted in movement/loss of stored micronutrients (Dipla et al, 2020. Bennell, Brukner, & Malcom 1996. Mehanna, Moledina, & Travis, 2008). For instance, it may be ideal to increase intake of vitamin D and calcium, either through supplementation with the guidance of a dietician/practitioner or through increased intake of food sources (Mountjoy et al). As LEA has the potential to negatively impact bone health, increasing these two micronutrients may be beneficial in supporting the mineralization of bone and improving bone density (Mountjoy et al. Dipla et al, 2020. Bennell, Brukner, & Malcom 1996).
In summary, dieting to lose large amounts of fat may infer negative physiological and psychological consequences if done to the extreme. Optimisation of post-competition nutrition in response to these issues may be beneficial in preventing the onset of refeeding syndrome, reducing risk of developing an eating disorder/mood disorders, and prevent unnecessary weight gain. However, there is still much to be learned about the consequences of RED-S and LEA, particularly effects of repeated exposure over the long-term, and how this may affect the athlete’s health and career.
References, and Further Reading
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Bennell, K. L., Brukner, P. D., & Malcolm, S. A. (1996). Effect of altered reproductive function and lowered testosterone levels on bone density in male endurance athletes. British journal of sports medicine, 30(3), 205–208.
Burke, L., Close, G., Lundy, B., Mooses, M. (2018). Relative Energy Deficiency in Sport in Male Athletes: A Commentary on Its Presentation Among Selected Groups of Male Athletes. International Journal of Sport Nutrition and Exercise Metabolism. 28(4), 1-11.
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