Figure 1: A recap of taste – foodstuffs, beverages or targeted tastants are applied to the oral cavity, and chemical and mechanical digestion being. Papillae increase surface area of the tongue, intensifying tastants and increasing potential likelihood of tastant: taste bud interaction. Taste buds are housed in papillae and are stimulated Oral cavity receives by tastants; upon stimulation they food and chemical digestion begins confer a chemosensory signal e.g. flavour, intensity, temperature, etc. Papillae located on tongue Adults typically possess 2000 – 4000 taste buds, and these are renewed approximately weekly. It is Taste buds stimulated important to consider that taste is not and confer just confined to the tongue, and that chemosensory signal people who have lost their sense of taste, may also be able to experience some of these tastes and their downstream effects, albeit differently from normal tasters. Figure 2: An overview of bitter tastants and their effects. Please note point 2, that ingestion is required for bitter tastants to be most 3. Brain regions associated effective and in point 4 autonomic with motor control and nervous system (ANS) stimulation emotion stimulated 4. Increased ANS has been noted to be longest and stimulation (long and strong) strongest following bitter tastants, 1. Ingestion of in comparison to sweet, sour or salty bitter taste tastes3. through foodstuffs or targeted intervention e.g. caffeine/quinine 2. Response greater when ingested compared to a swill, likely due to greater receptor 5. Increased motor output to muscles leading to interaction along GI tract improved maximal sprint performance Quinine, the tastant responsible for tonic taste receptors along the gastrointestinal and energy availability. Stimulation of these water’s distinctive flavour, has been shown tract, ingestion of quinine solutions is likely areas is thought to enhance motivation and to improve performance in a collection required to improve performance. Outside central drive, and thus improve power on of studies by Gam and colleagues4–6. of these works, there is relative paucity of the pedals. This has not only been shown to Enhancements in average power output studies employing bitter tastants, so further improve endurance performance, but may of 2.4% during a 30-sec maximal cycle investigation is encouraged, especially in also contribute to preservation of exercise were seen when quinine was swilled and the areas of strength and power activities intensity in repeated sprint protocols too8. ingested at a low concentration (2 mM), (Figure 2). Given the likely interaction between but not when quinine was only swilled at a feelings of energy availability and higher concentration (10 mM). It should be Sweet taste of success: Carbohydrate carbohydrate swilling, it is interesting and noted that these concentrations may elicit Carbohydrate mouth rinsing emerged as a important to note that these effects may nausea in some participants. strategy to improve performance in the early be more pronounced when undertaking This suggests that stimulating solely 2000’s following seminal work by James fasted exercise. This has implications for oral bitter receptors may not surpass a Carter and Asker Jeukendrup7. This work, the athlete and practitioner, and points currently undetermined receptor threshold which demonstrated improvements in 1-hr to a periodised and targeted approach to required to confer a meaningful effect upon cycling performance, led to the notion that carbohydrate swilling across the training performance, independent of bitterness some of carbohydrate’s ergogenic effects are cycle. intensity/ solution concentration. Hence, mediated by central pathways, stimulating Of further interest are the differential due to the location and density of bitter areas of the brain associated with reward effects seen when non-sweet carbohydrates WRIST AND HAND INJURIES TARGETED TOPIC 42 NOVEL PERFORMANCE SOLUTIONS 1. Carbohydrate signals incoming energy 2. Areas associated with pleasure and energy availability stimulated 3. Improved 4. Improved time to performance at the exhaustion and time muscle trial performance; most apparent when fasted Figure 3: An overview of carbohydrate tastes and their stimulatory and performance enhancing effects. and artificial sweeteners are compared. and assessed 1500m running performance, capsaicin mouth swill may directly target Non-sweet carbohydrates appear to improve four sets of 70% 1RM repeated squats to TRPV1 receptors but bypass the gut, performance and stimulate similar brain failure, and time to exhaustion during a hopefully alleviating symptoms. Whilst this regions to the same extent as sweet tasting repeated sprint protocol 15 second at velocity strategy did not improve repeated sprint carbohydrates, when swilled. However, equating to 120% VO2Peak with 15-second performance, it did not worsen it either, artificial sweeteners provide comparatively recoveries. Capsaicin supplementation and interestingly did not worsen sensations lower levels of brain stimulation, than their improved performance by 1.1 %, 23.2 % and of thermal sensation or comfort. Secondly, carbohydrate containing counterparts. This 14.0 % compared to placebo, respectively. capsiate, a non-pungent analogue of points to the potential for unidentified Concomitant significant reductions in capsaicin, has also been shown to stimulate carbohydrate receptors within the RPE were also seen, alluding to capsaicin’s TRPV1 receptors and elicit similar biological oral cavity9, and further supports the analgesic effect. Increased endurance may effects to capsaicin in humans and rodent evolutionary perspective that a function of also be a product of increased lipolysis models, but notably does not confer a taste, is to simply confer energy availability and or increased calcium release at warming sensation. Further work on and prime one’s system for its imminent the sarcoplasmic reticulum by TRP-V1 capsiate is required to confirm its ergogenic ingestion (Figure 3). stimulation. potential in sports, but like carbohydrate These promising results suggests that swilling, it may be the stimulation of Feeling hot: Capsaicin ingesting capsaicin may be ergogenic across targeted receptors that is of importance, as The hot sensation we experience when a range of sporting scenarios. However, when opposed to taste, when it comes to running eating chilli comes from capsaicin capsaicin is consumed in foods, the potential faster, lifting more, or lasting longer. stimulating transient receptor potential side effects may outweigh its ergogenic vanilloid-1 proteins (TRPV1). TRPV1 are also potential. TRPV1 receptors are found along Fresh perspective: Menthol stimulated during hot temperatures (>35ºC), the entire digestive tract, thus the possibility Menthol is familiar for its minty flavour, hence capsaicin containing foods feel and of gastrointestinal discomfort is increased feeling and tasting cool, and almost taste hot10. This perceptual heat extends following capsaicin induced stimulation of ubiquitous in everyday oral hygiene to topical application; most sports medics these receptors, in doses from as low as 1mg. products, confectionary etc. Menthol will be familiar with warming topical Opheim & Rankin’s11 participants reported achieves the cooling part of its flavour ointments, patches and sprays as targeted gastrointestinal symptoms increased 6.3 profile via stimulating transient receptor analgesic treatments. times compared to placebo and resulted in melastatin 8 (TRP-M8) receptors, this Four studies have investigated capsaicin’s the withdrawal of three participants, thus mimics a cold temperature range of 8-28ºC, ergogenic properties via ingestion or mouth capsaicin induced GI discomfort may even and so reduces thermal sensation (how swilling. Three of these studies employed impair performance. hot am I?) and improves thermal comfort a consistent dose and timing (12mg Two possible solutions exist at present, (how comfortable am I in the heat?). These administered 45-minutes pre-performance), firstly as proposed by Gibson et al.,12, a effects are particularly powerful when 43 menthol is swilled or ingested because Despite menthol’s ability to impart used to desensitise the mouth prior to menthol’s effects are greater when skin is subjective improvements, no changes in dental procedures, suggesting that their thinner, hence lower concentrations can body temperature have been reported to administration prior to exercise may confer be used than when applying menthol to date when menthol is applied exclusively. an analgesic effect too. Preliminary work the skin13. Of further relevance to sport, is Physiological cooling strategies such as ice has shown that repeatedly swilling a 6% that TRP-M8 activity can be increased with slurries may make an effective partner to salt solution during a 30min cycle, preserved airflow. Whilst this can be engineered in menthol’s subjective cooling effects, but maximal voluntary contractile ability in the laboratory through manipulating wind- anecdotally there is an increased risk for comparison to a water only control16 ­ these – speed and air density, it is likely that this is of “brain freeze” in some individuals, which effects were comparable to glucose swilling. greater importance when applying menthol obviously detracts from performance. An Extrapolating these findings hints at a in the field, as athletes typically experience emerging secondary effect of menthol use potential alternative swill either for athletes faster wind and performance velocities. is its ability to reduce thirst, however the who don’t have a sweet tooth, or later in To date menthol’s effects upon potential importance of this to improve events when flavour fatigue may occur. intermittent and time to exhaustion cycling, or impair performance is unknown; Pickle juice has also been shown to as well as running time trial performance highlighting that menthol should be applied affect the central nervous system when have been assessed in hot conditions (all to sport cautiously15, especially if water taken during exercise, reportedly having >30ºC). Intermittent performance did not intake is limited due to event demands e.g. anti-cramping effects17. This evidence is improve, however time to exhaustion ultramarathon, or in athletes with high preliminary, but has strong anecdotal and time trial performance showed sweat rates (Figure 4). backing from endurance athletes and trivial-moderate improvements (Hedge’s supporting practitioners that warrants g: 0.40; 0.04 – 0.7614) following menthol The future of food engineering? further exploration. Pickle juice also mouth swilling. As mentioned above, Whilst we have focused upon those tastes represents the first strategy that could improvements in thermal comfort and with a somewhat established body of be described as a ‘composite taste’, thermal sensation were reported across research, there are emerging tastes that also incorporating elements of acid, bitter, sweet these studies, with an increase in ventilation may prove ergogenic in the future. and warmth. Teasing out the ergogenic also commonly seen. Salt (NaCl) solutions are commonly effects attributable to each taste would 1. Thermal tastant binds to targeted receptor 2. Stimulation mimics cold or hot temperature range 3. Alterations in perception TR of factors such as: PM 8 (M Rec • Pain sensitivity ent ept h o or • Respiratory drive l) • Thermal comfort • Thermal sensation • Thirst TR (Cap PV sa 1 R icin ec ) ep tor Figure 4: Thermal tastants and their potential perceptual effects. Note that these tastes are probably the best demonstration we have within taste of evolutionary economy, whereby a thermal taste can infer similar responses to that of real changes in temperature/thermal strain and the accompanying perceptual responses too. The reader is also reminded that when these chemical compounds (menthol and capsaicin) are applied topically, we see similar perceptual responses to those listed here, but differing physiological responses. Readers are directed to references (x) and (y), for menthol and capsaicin, respectively. WRIST AND HAND INJURIES TARGETED TOPIC 44 NOVEL PERFORMANCE SOLUTIONS Carbohydrate – range of activities where glycogen availability may limit performance; consideration of an athlete’s nutritional status and purpose(s) of training session(s) is required. Bitter tastes – power type activities of a short duration; anhydrous caffeine or quinine may not always be available to athletes, so products containing these ingredients whilst retaining bitterness should be considered. Menthol – short to moderate endurance events, ~15 - 60 minutes long, especially in the heat. Hydration needs of the athlete also need to be considered, as does pairing with other cooling Tastant strategies. Strength Power Repeated Sprint Endurance Capsaicin – short duration, anaerobic and aerobic power events ≤ 5 minutes long. It is recommended that this be ingested in a capsule as opposed to * real food form to avoid GI distress and performance impairment * Figure 5: Overview of main tastants detailed in the * Ingestion may be required to see beneficial effects from these tastants present article. be a substantial undertaking, but it is Placebo: a potential problem or performance Extending upon these interactions, encouraging that real foodstuffs, that are enhancer? taste may confer a placebo effect either readily available and affordable to many Placebo effects are a common topic of by manipulating perceptions of resource may prove mechanistically beneficial to discussion in sports science literature and allocation, or affecting the endogenous performance. practice, but whilst experimentally they opioid system. As evidenced above, Even established sports nutrition should be controlled for, in practice they carbohydrate solutions may impart strategies may improve performance may enhance performance by similar sensations of fuel availability and thus by mechanisms indirectly related to magnitudes to nutritional or mechanical direct resources in favour of a greater energy taste. Beetroot juice, a source of dietary strategies (d = 0.35 – 0.47;19) and so present output, whereas capsaicin or salt may confer nitrate, which has been shown to another strategy in the applied sports analgesic effects. This is not to say that these improve endurance performance via the scientist’s toolbox. responses are entirely the result of a placebo nitrate ? nitrite ? nitric oxide pathway, is Placebo effects have been attributed to effect, but that the placebo effect may be activated via enzymes in the oral cavity18. a range of psychological and physiological partly responsible, and likely responds to Furthermore, interindividual differences in mechanisms but in the context of sports similar neurobiological pathways, that are response to beetroot juice supplementation performance, it may be the psychosocial being stimulated by these tastants1. may partially be explained by the oral relationship between athletes, practitioners microbiome of those consuming it18. and the environment in which a strategy Which taste, when? Not only is the oral microbiome altered is implemented that manifest in improved Much like matching wine and food, the by dietary nitrate consumption, but the performance1. These effects may be further evidence points to pairing specific tastes physiological response to it also correlates enhanced through manipulation of with certain sporting scenarios, but to microbial abundance. This presents an strategy-specific factors such as colour20, individual preference will trump evidence exciting avenue for the future intersection dose, form and language used to describe if these tastants are not administered in a of ‘omics’, taste research and sports science. the strategy19. manner that is practical and/ or tolerable 45 bitter taste? Medical Hypotheses. 2019 2019 Jun;22(6):707–15. and is meaningful to the athlete and their Oct;131:109301. 15. Barwood MJ, Gibson OR, Gillis DJ, Jeffries performance. The potential for deleterious 4. Gam S, Guelfi KJ, Fournier PA. Mouth O, Morris NB, Pearce J, et al. Menthol gastrointestinal side effects when most rinsing and ingesting a bitter solution as an Ergogenic Aid for the Tokyo 2021 tastants are improperly administered is improves sprint cycling performance. Olympic Games: An Expert-Led Consensus likely due to an overstimulation of pertinent Medicine & Science in Sports & Exercise. Statement Using the Modified Delphi receptors, so thorough trials in key training 2014 Aug;46(8):1648–57. Method. Sports Medicine. 2020 Jul 1;1–19. sessions are warranted. In the field, where winning matters more than the smallest 5. Gam S, Tan M, Guelfi KJ, Fournier PA. 16. Khong TK, Selvanayagam VS, Yusof A. Mouth rinsing with a bitter solution Effect of glucose and sodium chloride worthwhile change, placebo effects may without ingestion does not improve sprint mouth rinses on neuromuscular fatigue: also be maximised with a view to further cycling performance. European Journal of a preliminary study. European Journal of enhancing these strategies. In summary, the Applied Physiology. 2015 Jan;115(1):129–38. Sport Science. 2020 Feb 14;0(0):1–17. following taste and activity pairings provide a starting point: 6. Gam S, Guelfi KJ, Hammond G, Fournier PA. 17. Nelson NL, Churilla JR. A narrative review Mouth rinsing and ingestion of a bitter- of exercise-associated muscle cramps: • Bitter tastes – power type activities of tasting solution increases corticomotor Factors that contribute to neuromuscular a short duration; anhydrous caffeine or excitability in male competitive cyclists. fatigue and management implications. European Journal of Applied Physiology. Muscle & Nerve [Internet]. 2016 May quinine may not always be available to 2015 Oct;115(10):2199–204. 27;54(2):177–85. athletes, so products containing these ingredients whilst retaining bitterness 7. Carter JM, Jeukendrup AE. The effect of 18. Vanhatalo A, Blackwell JR, L’Heureux JE, should be considered. carbohydrate mouth rinse on 1-h cycle Williams DW, Smith A, Giezen M van der, • Carbohydrate – range of activities time trial performance. Medicine & et al. Nitrate-responsive oral microbiome where glycogen availability may Science in Sports & Exercise. 2004 Dec modulates nitric oxide homeostasis and limit performance; consideration of 1;36(12):2107-11 blood pressure in humans. Free Radic an athlete’s nutritional status and 8. Beaven CM, Maulder P, Pooley A, Biology Medicine. 2018;124:21–30. purpose(s) of training session(s) is Kilduff L, Cook C. Effects of caffeine and 19. Hurst P, Schipof-Godart L, Szabo A, Raglin required. carbohydrate mouth rinses on repeated J, Hettinga F, Roelands B, et al. The Placebo • Capsaicin – short duration, anaerobic sprint performance. Applied Physiology, and Nocebo effect on sports performance: and aerobic power events ≤ 5 minutes Nutrition, and Metabolism. 2013 A systematic review. European Journal of long. It is recommended that this be Jun;38(6):633–7. Sport Science. 2019 Aug 20;46(1):1–14. ingested in a capsule as opposed to 9. Burke LM, Maughan RJ. The Governor 20. Best R, Spears I, Hurst P, Berger N. The real food form to avoid GI distress and has a sweet tooth – Mouth sensing of Development of a Menthol Solution for performance impairment. nutrients to enhance sports performance. Use during Sport and Exercise. Beverages. • Menthol – short to moderate endurance European Journal of Sport Science. 2014 2018 Jun;4(2):44–10. events, ~15 - 60 minutes long, especially Oct 23;15(1):29–40. in the heat. Hydration needs of the 10. Simon SA, Araujo IE de. The salty and athlete also need to be considered, burning taste of capsaicin. The Journal of as does pairing with other cooling general physiology. 2005 Jun;125(6):531–4. strategies (Figure 5). 11. Opheim MN, Rankin JW. Effect of capsaicin supplementation on repeated sprinting performance. Journal of strength Images in this article were created using and conditioning research / National unsplash.com (Smart servier medical art) Strength & Conditioning Association. under CC Attribution 3.0 license. 2012 Feb;26(2):319–26. 12. Gibson OR, Wrightson JG, Hayes M. Russ Best TITLE Intermittent sprint performance in the heat is not altered by augmenting POSITION References thermal perception via L-menthol Centre for Sport Science and Human 1. Best R, McDonald K, Hurst P, Pickering C. or capsaicin mouth rinses. European Performance, Waikato Institute of Can taste be ergogenic? European Journal Journal of Applied Physiology. 2018 Dec Technology, of Nutrition. 2020 May 17;1–10. 22;46(Suppl 1):936–12. Hamilton, New Zealand 2. Gam S, Guelfi KJ, Fournier PA. New 13. Stevens CJ, Best R. Menthol: A Fresh Centre for Health and Social Practice, Insights into Enhancing Maximal Ergogenic Aid for Athletic Performance. Teesside University, Exercise Performance Through the Use Sports Medicine. 2017 Jun;47(6):1035–42. Middlesbrough, United Kingdom of a Bitter Tastant. Sports Medicine. 2016 14. Jeffries O, Waldron M. The effects of Mar 21;46(10):1385–90. menthol on exercise performance and Contact: russell.best@wintec.ac.nz 3. Pickering C. Are caffeine’s performance- thermal sensation: A meta-analysis. enhancing effects partially driven by its Journal of Science and Medicine in Sport. WRIST AND HAND INJURIES TARGETED TOPIC 46