Abstract
Taste is a homeostatic function that conveys valuable information, such as energy density, readiness to eat, or toxicity of foodstuffs. Taste is not limited to the oral cavity but affects multiple physiological systems. In this review, we outline the ergogenic potential of substances that impart bitter, sweet, hot and cold tastes administered prior to and during exercise performance and whether the ergogenic benefits of taste are attributable to the placebo effect. Carbohydrate mouth rinsing seemingly improves endurance performance, along with a potentially ergogenic effect of oral exposure to both bitter tastants and caffeine although subsequent ingestion of bitter mouth rinses is likely required to enhance performance. Hot and cold tastes may prove beneficial in circumstances where athletes’ thermal state may be challenged. Efficacy is not limited to taste, but extends to the stimulation of targeted receptors in the oral cavity and throughout the digestive tract, relaying signals pertaining to energy availability and temperature to appropriate neural centres. Dose, frequency and timing of tastant application likely require personalisation to be most effective, and can be enhanced or confounded by factors that relate to the placebo effect, highlighting taste as a critical factor in designing and administering applied sports science interventions.
Similar content being viewed by others
References
Breslin PAS (2013) An evolutionary perspective on food review and human taste. Curr Biol 23:R409–R418
Bachmanov AA, Bosak NP, Lin C, Matsumoto I, Ohmoto M, Reed DR et al (2014) Genetics of taste receptors. Curr Pharm Des 20:2669–2683
Reed DR, Knaapila A (2010) Genetics of taste and smell. Genes Obesity 94:213–240
Devillier P, Naline E, Grassin-Delyle S (2015) The pharmacology of bitter taste receptors and their role in human airways. Pharmacol Ther 155:11–21
Freund JR, Lee RJ (2018) Taste receptors in the upper airway. World J Otorhinolaryngol Head Neck Surg 4:67–76
Spence C (2015) On the psychological impact of food colour. Flavour 4:21
Skinner M, Eldeghaidy S, Ford R, Giesbrecht T, Thomas A, Francis S et al (2018) Variation in thermally induced taste response across thermal tasters. Physiol Behav 188:67–78
Spence C (2015) Just how much of what we taste derives from the sense of smell? Flavour 4:1–10
Small DM (2012) Flavor is in the brain. Physiol Behav 107:540–552
Frasnelli J, Albrecht J, Bryant B, Lundström JN (2011) Perception of specific trigeminal chemosensory agonists. Neuroscience 189:377–383
Stevens CJ, Best R (2017) Menthol: a fresh ergogenic aid for athletic performance. Sports Med 47:1035–1042
Gibson OR, Wrightson JG, Hayes M (2018) Intermittent sprint performance in the heat is not altered by augmenting thermal perception via l-menthol or capsaicin mouth rinses. Eur J Appl Physiol 46:936–1012
de Freitas MC, Cholewa JM, Freire RV, Carmo BA, Bottan J, Bratfich M et al (2017) Acute capsaicin supplementation improves resistance training performance in trained men. J Strength Cond Res 32:1–21
Burke LM, Maughan RJ (2014) The governor has a sweet tooth–mouth sensing of nutrients to enhance sports performance. Eur J Sport Sci 15:29–40
Pickering C (2019) Are caffeine’s performance-enhancing effects partially driven by its bitter taste? Med Hypotheses 131:109301
Fares EJM, Kayser B (2011) Carbohydrate mouth rinse effects on exercise capacity in pre- and postprandial states. J Nutr Metab 2011:385962
Chambers ES, Bridge MW, Jones DA (2009) Carbohydrate sensing in the human mouth: effects on exercise performance and brain activity. J Phys 587:1779–1794
Jeffries O, Waldron M (2019) The effects of menthol on exercise performance and thermal sensation: a meta-analysis. J Sci Med Sport 22:707–715
Gam S, Guelfi KJ, Fournier PA (2016) New insights into enhancing maximal exercise performance through the use of a bitter tastant. Sports Med 46:1385–1390
Rousmans S, Robin O, Dittmar A, Vernet-Maury E (2000) Autonomic nervous system responses associated with primary tastes. Chem Senses 25:709–718
Leterme A, Brun L, Dittmar A, Robin O (2008) Autonomic nervous system responses to sweet taste: evidence for habituation rather than pleasure. Physiol Behav 93:994–999
Michlig S, Merlini JM, Beaumont M, Ledda M, Tavenard A, Mukherjee R et al (2016) Effects of TRP channel agonist ingestion on metabolism and autonomic nervous system in a randomized clinical trial of healthy subjects. Nature 6:1–12
Eccles R (2000) Role of cold receptors and menthol in thirst, the drive to breathe and arousal. Appetite 34:29–35
Eccles R, Du-Plessis L, Dommels Y, Wilkinson JE (2013) Cold pleasure. Why we like ice drinks, ice-lollies and ice cream. Appetite 71:357–360
Flood TR, Waldron M, Jeffries O (2017) Oral l-menthol reduces thermal sensation, increases work-rate and extends time to exhaustion, in the heat at a fixed rating of perceived exertion. Eur J Appl Physiol 117:1501–1512
Mündel T, Jones DA (2009) The effects of swilling an l (−)-menthol solution during exercise in the heat. Eur J Appl Physiol 109:59–65
Stevens CJ, Thoseby B, Sculley DV, Callister R, Taylor L, Dascombe BJ (2016) Running performance and thermal sensation in the heat are improved with menthol mouth rinse but not ice slurry ingestion. J Appl Physiolo 26:1209–1216
Beedie C, Benedetti F, Barbiani D, Camerone E, Cohen E, Coleman D et al (2018) Consensus statement on placebo effects in sports and exercise: the need for conceptual clarity, methodological rigour, and the elucidation of neurobiological mechanisms. Eur J Sport Sci 18:1383–1389
Best R, Spears I, Hurst P, Berger N (2018) The development of a menthol solution for use during sport and exercise. Beverages 4:44–10
Stellingwerff T, Cox GR (2014) Systematic review: carbohydrate supplementation on exercise performance or capacity of varying durations 1. Appl Physiol Nutr Metab 39:998–1011
McConell GK, Canny BJ, Daddo MC, Nance MJ, Snow RJ (2000) Effect of carbohydrate ingestion on glucose kinetics and muscle metabolism during intense endurance exercise. J Appl Physiol 89:1690–1698
Carter JM, Jeukendrup AE, Mann CH, Jones DA (2004) The effect of glucose infusion on glucose kinetics during a 1-h time trial. Med Sci Sports Exerc 36:1543–1550
Rollo DI, Williams C (2011) Effect of mouth-rinsing carbohydrate solutions on endurance performance. Sports Med 41:449–461
Jeukendrup AE, Chambers ES (2010) Oral carbohydrate sensing and exercise performance. Current Opinion Clinic Nutr Metab Care 13:447–451
de Ataide e Silva T, de DiCavalcanti AlvesSouza ME, de Amorim JF, Stathis CG, Leandro CG, Lim-Silva AE (2013) Can carbohydrate mouth rinse improve performance during exercise? a systematic review. Nutrients 6:1–10
Brietzke C, Franco-Alvarenga PE, Coelho-Júnior HJ, Silveira R, Asano RY, Pires FO (2019) Effects of carbohydrate mouth rinse on cycling time trial performance: a systematic review and meta-analysis. Sports Med 49:57–66
Berthoud H-R (2003) Neural systems controlling food intake and energy balance in the modern world. Current Opinion Clinic Nutr Metab Care 6:615–620
de Araujo IE, Ren X, Ferreira JG (2010) Metabolic sensing in brain dopamine systems. In: Meyerhof W, Beisiegel U, Joost H-G (eds) Sensory and metabolic control of energy balance. Springer, Heidelberg, pp 69–86
Noakes TD (2007) The central governor model of exercise regulation applied to the marathon. Sports Med 37:374–377
Marcora S (2009) Perception of effort during exercise is independent of afferent feedback from skeletal muscles, heart, and lungs. J Appl Physiol 106:2060–2062
Frank GKW, Oberndorfer TA, Simmons AN, Paulus MP, Fudge JL, Yang TT et al (2008) Sucrose activates human taste pathways differently from artificial sweetener. NeuroImage 39:1559–1569
Zald DH, Hagen MC, Pardo JV (2002) Neural correlates of tasting concentrated quinine and sugar solutions. J Neurophysiol 87:1068–1075
Gam S, Guelfi KJ, Fournier PA (2014) Mouth rinsing and ingesting a bitter solution improves sprint cycling performance. Med Sci Sports Exerc 46:1648–1657
Gam S, Tan M, Guelfi KJ, Fournier PA (2015) Mouth rinsing with a bitter solution without ingestion does not improve sprint cycling performance. Eur J Appl Physiol 115:129–138
Behrens M, Foerster S, Staehler F, Raguse J-D, Meyerhof W (2007) Gustatory expression pattern of the human TAS2R bitter receptor gene family reveals a heterogenous population of bitter responsive taste receptor cells. J Neurosci Soc Neurosci 27:12630–12640
Gam S, Guelfi KJ, Hammond G, Fournier PA (2015) Mouth rinsing and ingestion of a bitter-tasting solution increases corticomotor excitability in male competitive cyclists. Eur J Appl Physiol 115:2199–2204
Poole RL, Tordoff MG (2017) The taste of caffeine. J Caffeine Res 7:39–52
Meyerhof W, Batram C, Kuhn C, Brockhoff A, Chudoba E, Bufe B et al (2010) The molecular receptive ranges of human TAS2R bitter taste receptors. Chem Senses 35:157–170
Grgic J, Grgic I, Pickering C, Schoenfeld BJ, Bishop DJ, Pedisic Z (2019) Wake up and smell the coffee: caffeine supplementation and exercise performance—an umbrella review of 21 published meta-analyses. British J Sports Med 2018:100278
Beaven CM, Maulder P, Pooley A, Kilduff L, Cook C (2013) Effects of caffeine and carbohydrate mouth rinses on repeated sprint performance. Appl Physiol Nutr Metab 38:633–637
Doering TM, Fell JW, Leveritt MD, Desbrow B, Shing CM (2014) The effect of a caffeinated mouth-rinse on endurance cycling time-trial performance. Int J Sport Nutr Exerc Metab 24:90–97
Clarke ND, Kornilios E, Richardson DL (2015) Carbohydrate and caffeine mouth rinses do not affect maximum strength and muscular endurance performance. J Strength Cond Res 29:2926–2931
Kizzi J, Sum A, Houston FE, Hayes LD (2016) Influence of a caffeine mouth rinse on sprint cycling following glycogen depletion. Eur J Sport Sci 16:1–8
Pataky MW, Womack CJ, Saunders MJ, Goffe JL, D'Lugos AC, El-Sohemy A et al (2016) Caffeine and 3-km cycling performance: effects of mouth rinsing, genotype, and time of day. J Appl Physiol 26:613–619
Dolan P, Witherbee KE, Peterson KM, Kerksick CM (2017) Effect of carbohydrate, caffeine, and carbohydrate + caffeine mouth rinsing on intermittent running performance in collegiate male lacrosse athletes. J Strength Cond Res 31:2473–2479
Bottoms L, Hurst H, Scriven A, Lynch F, Bolton J, Vercoe L et al (2014) The effect of caffeine mouth rinse on self-paced cycling performance. Comp Exerc Physiol 10:239–245
Pomportes L, Brisswalter J, Casini L, Hays A, Davranche K (2017) Cognitive performance enhancement induced by caffeine, carbohydrate and guarana mouth rinsing during submaximal exercise. Nutrients 9:589
Van Cutsem J, De Pauw K, Marcora S, Meeusen R, Roelands B (2018) A caffeine-maltodextrin mouth rinse counters mental fatigue. Psychopharmacology 235:947–958
Rozengurt E (2006) Taste receptors in the gastrointestinal tract. I. Bitter taste receptors and alpha-gustducin in the mammalian gut. Am J Physiol Gastrointest Liver Physiol 291:G171–G177
Macneish RS (1964) Ancient Mesoamerican civilization. Science 143:531–537
Fattori V, Hohmann MSN, Rossaneis AC, Pinho-Ribeiro FA, Verri WA (2016) Capsaicin: current understanding of its mechanisms and therapy of pain and other pre-clinical and clinical uses. Molecules 21:844
Simon SA, de Araujo IE (2005) The salty and burning taste of capsaicin. J Gen Physiol 125:531–534
Caterina MJ, Schumacher MA, Tominaga M, Rosen TA, Levine JD, Julius D (1997) The capsaicin receptor: a heat-activated ion channel in the pain pathway. Nature 389:816–824
Opheim MN, Rankin JW (2012) Effect of capsaicin supplementation on repeated sprinting performance. J Strength Cond Res 26:319–326
de Freitas MC, Cholewa JM, Gobbo LA, de Oliveira JVNS, Lira FS, Rossi FE (2018) Acute capsaicin supplementation improves 1,500-m running time-trial performance and rate of perceived exertion in physically active adults. J Strength Cond Res 32:572–577
de Freitas MC, Billaut F, Panissa VLG, Rossi FE, Figueiredo C, Caperuto EC et al (2019) Capsaicin supplementation increases time to exhaustion in high-intensity intermittent exercise without modifying metabolic responses in physically active men. Eur J Appl Physiol 119:971–979
Lotteau S, Ducreux S, Romestaing C, Legrand C, Van Coppenolle F (2013) Characterization of functional TRPV1 channels in the sarcoplasmic reticulum of mouse skeletal muscle. PLoS ONE 8:e58673
Glickman-Weiss EL, Hearon CM, Nelson AG, Day R (1998) Does capsaicin affect physiologic and thermal responses of males during immersion in 22 degrees C? Aviat Space Environ Med 69:1095–1099
Haramizu S, Mizunoya W, Masuda Y, Ohnuki K, Watanabe T, Yazawa S et al (2006) Capsiate, a nonpungent capsaicin analog, increases endurance swimming capacity of mice by stimulation of vanilloid receptors. Biosci Biotechnol Biochem 70:774–781
Shin KO, Yeo NH, Kang S (2010) Autonomic nervous activity and lipid oxidation postexercise with capsaicin in the humans. J Sports Sci Med 9:253–261
Lim K, Yoshioka M, Kikuzato S, Kiyonaga A, Tanaka H, Shindo M et al (1997) Dietary red pepper ingestion increases carbohydrate oxidation at rest and during exercise in runners. Med Sci Sports Exerc 29:355–361
Oh T-W, Ohta F (2003) Dose-dependent effect of capsaicin on endurance capacity in rats. Br J Nutr 90:515–520
Kim KM, Kawada T, Ishihara K, Inoue K, Fushiki T (1997) Increase in swimming endurance capacity of mice by capsaicin-induced adrenal catecholamine secretion. Biosci Biotechnol Biochem 61:1718–1723
Kim KM, Kawada T, Ishihara K, Inoue K, Fushiki T (1998) Swimming capacity of mice is increased by oral administration of a nonpungent capsaicin analog, stearoyl vanillylamide. J Nutr 128:1978–1983
Yu X, Yu M, Liu Y, Yu S (2015) TRP channel functions in the gastrointestinal tract. Semin Immunopathol 38:385–396
Li X, Cao Y, Wong RKM, Ho KY, Wilder-Smith CH (2013) Visceral and somatic sensory function in functional dyspepsia. Neurogastroenterol Motil 25(3):246–e165
Iida T, Moriyama T, Kobata K, Morita A, Murayama N, Hashizume S et al (2003) TRPV1 activation and induction of nociceptive response by a non-pungent capsaicin-like compound, capsiate. Neuropharmacology 44:958–967
Patel T, Ishiuji Y, Yosipovitch G (2007) Menthol: a refreshing look at this ancient compound. J Am Acad Dermatol 57:873–878
Watson HR, Hems R, Rowsell DG, Spring DJ (1978) New compounds with the menthol cooling effect. J Soc Cosmet Chem 29:185–200
Best R, Payton S, Spears I, Riera F, Berger N (2018) Topical and ingested cooling methodologies for endurance exercise performance in the heat. Sports 6:11–21
Cometto-Muñiz JE, Cain WS (1990) Thresholds for odor and nasal pungency. Physiol Behav 48:719–725
Viana F (2011) Chemosensory properties of the trigeminal system. ACS Chem Neurosci 2:38–50
Kollndorfer K, Kowalczyk K, Frasnelli J, Hoche E, Unger E, Mueller CA et al (2015) Same same but different. different trigeminal chemoreceptors share the same central pathway. PLoS ONE 10:e0121091–e121112
Murphy C (1983) Age-related effects on the threshold, psychophysical function, and pleasantness of menthol. J Gerontol 38:217–222
Saint-Eve A, Déléris I, Feron G, Ibarra D, Guichard E, Souchon I (2010) How trigeminal, taste and aroma perceptions are affected in mint-flavored carbonated beverages. Food Qual Prefer 21:1026–1033
Riera F, Trong TT, Sinnapah S, Hue O (2014) Physical and perceptual cooling with beverages to increase cycle performance in a tropical climate. PLoS ONE 9:e103718–e103727
Riera F, Trong T, Rinaldi K, Hue O (2016) precooling does not enhance the effect on performance of midcooling with ice-slush/menthol. Int J Sports Med 37:1025–1031
Tran Trong T, Riera F, Rinaldi K, Briki W, Hue O (2015) Ingestion of a cold temperature/menthol beverage increases outdoor exercise performance in a hot, humid environment. PLoS ONE 10:e0123815
Siegel R, Laursen PB (2012) Keeping your cool. Sports Med 42:89–98
Mages S, Hensel O, Zierz AM, Kraya T, Zierz S (2017) Experimental provocation of “ice-cream headache” by ice cubes and ice water. Cephalalgia 37:464–469
Hulihan J (1997) Ice cream headache. BMJ 314:1364
Jeffries O, Goldsmith M, Waldron M (2018) L-Menthol mouth rinse or ice slurry ingestion during the latter stages of exercise in the heat provide a novel stimulus to enhance performance despite elevation in mean body temperature. Eur J Appl Physiol 118:2435–2442
Stevens CJ, Bennett KJM, Sculley DV, Callister R, Taylor L, Dascombe BJ (2016) A comparison of mixed-method cooling interventions on pre-loaded running performance in the heat. J Strength Cond Res 1:28
Kupari J, Häring M, Agirre E, Castelo-Branco G, Ernfors P (2019) An atlas of vagal sensory neurons and their molecular specialization. Cell Reports 27(2508–2523):e4
Kaczyńska K, Szereda-Przestaszewska M (2013) Nodose ganglia-modulatory effects on respiration. Physiol Res 62:227–235
Baraniuk JN, Merck SJ (2008) Nasal reflexes: implications for exercise, breathing, and sex. Curr Allergy Asthma Rep 8:147–153
Naito K, Komori M, Kondo Y, Takeuchi M, Iwata S (1997) The effect of l-menthol stimulation of the major palatine nerve on subjective and objective nasal patency. Auris Nasus Larynx 24:159–162
Eccles R (2003) Menthol: effects on nasal sensation of airflow and the drive to breathe. Curr Allergy Asthma Rep 3:210–214
Thornton SN (2010) Thirst and hydration: physiology and consequences of dysfunction. Physiol Behav 100:15–21
van Belzen L, Postma EM, Boesveldt S (2017) How to quench your thirst. The effect of water-based products varying in temperature and texture, flavour, and sugar content on thirst. Physiol Behav 180:45–52
Peyrot des Gachons C, Avrillier J, Gleason M, Algarra L, Zhang S, Mura E et al (2016) Oral cooling and carbonation increase the perception of drinking and thirst quenching in thirsty adults. PLoS ONE 1:e0162261–e162312
Mündel T, King J, Collacott E, Jones DA (2006) Drink temperature influences fluid intake and endurance capacity in men during exercise in a hot, dry environment. Exp Physiol 91:925–933
Lee JKW, Shirreffs SM (2007) The influence of drink temperature on thermoregulatory responses during prolonged exercise in a moderate environment. J Sports Sci 25:975–985
Labbe D, Almiron-Roig E, Hudry J, Leathwood P, Schifferstein HNJ, Martin N (2009) Sensory basis of refreshing perception: role of psychophysiological factors and food experience. Physiol Behav 98:1–9
Labbe D, Gilbert F, Antille N, Martin N (2009) Sensory determinants of refreshing. Food Qual Prefer 20:100–109
Fenko A, Schifferstein HNJ, Huang T-C, Hekkert P (2009) What makes products fresh: the smell or the colour? Food Qual Prefer 20:372–379
Best R, Barwick B, Best A, Berger N, Harrison C, Wright M et al (2018) Changes in pain and nutritional intake modulate ultra-running performance: a case report. Sports 6:111–113
Hoffman MD, Stellingwerff T, Costa RJS (2018) Considerations for ultra-endurance activities: part 2 – hydration. Res Sports Med 00:1–13
Armstrong LE, Hubbard RW, Jones BH, Daniels JT (2016) Preparing alberto salazar for the heat of the 1984 olympic marathon. Phys Sports Med 14:73–81
Shepherd K, Peart DJ (2017) Aerobic capacity is not improved following 10-day supplementation with peppermint essential oil. Appl Physiol Nutr Metab 42:558–561
Hurst P, Foad A, Coleman D, Beedie C (2017) Athletes intending to use sports supplements are more likely to respond to a placebo. Med Sci Sports Exerc 49:1877–1883
Hurst P, Schiphof-Godart L, Hettinga F, Roelands B, Beedie C (2019) Improved 1000-m running performance and pacing strategy with caffeine and placebo effect: a balanced placebo design study. Int J Physiol Perf 9(1):1–6
Ross R, Gray CM, Gill JMR (2015) Effects of an injected placebo on endurance running performance. Med Sci Sports Exerc 47:1672–1681
Hurst P, Schipof-Godart L, Szabo A, Raglin J, Hettinga F, Roelands B et al (2019) The placebo and nocebo effect on sports performance: a systematic review. Eur J Sport Sci 46:1–14
Beedie C, Benedetti F, Barbiani D, Camerone E, Lindheimer J, Roelands B (2019) Incorporating methods and findings from neuroscience to better understand placebo and nocebo effects in sport. Eur J Sport Sci 7:1–13
Humphrey N (2002) Great expectations: the evolutionary psychology of faith-healing and the placebo effect. Psychol Turn Millenn 225:246
Miller FG, Colloca L, Kaptchuk TJ (2009) The placebo effect: illness and interpersonal healing. Perspect Biol Med 52:518–539
Ader R, Cohen N (1975) Behaviorally conditioned immunosuppression. Psychosom Med 37:333–340
Olness K, Ader R (1992) Conditioning as an adjunct in the pharmacotherapy of lupus erythematosus. J Dev Behav Pediatr 13:124–125
Smits RM, Veldhuijzen DS, Wulffraat NM, Evers AWM (2018) The role of placebo effects in immune-related conditions: mechanisms and clinical considerations. Expert Rev Clin Immunol 14:761–770
Benedetti F (2013) Placebo and the new physiology of the doctor–patient relationship. Physiol Rev 93:1207–1246
Colloca L (2019) The placebo effect in pain therapies. Annu Rev Pharmacol Toxicol 59:191–211
Amanzio M, Benedetti F (1999) Neuropharmacological dissection of placebo analgesia: expectation-activated opioid systems versus conditioning-activated specific subsystems. J Neurosci 19:484–494
Wager TD, Scott DJ, Zubieta J-K (2007) Placebo effects on human μ-opioid activity during pain. Proc Natl Acad Sci USA 104:11056–11061
Zubieta J-K, Bueller JA, Jackson LR, Scott DJ, Xu Y, Koeppe RA et al (2005) Placebo effects mediated by endogenous opioid activity on μ-opioid receptors. J Neurosci Soc Neurosci 25:7754–7762
Jain R, Mukherjee K, Singh R (2004) Influence of sweet tasting solutions on opioid withdrawal. Brain Res Bull 64:319–322
Lewkowski MD, Young SN, Ghosh S, Ditto B (2008) Effects of opioid blockade on the modulation of pain and mood by sweet taste and blood pressure in young adults. Pain 135:75–81
Wise PM, Breslin PAS, Dalton P (2014) Effect of taste sensation on cough reflex sensitivity. Lung 192:9–13
Pelchat ML (2002) Of human bondage: food craving, obsession, compulsion, and addiction. Physiol Behav 76:347–352
Ramenghi LA, Evans DJ, Levene MI (1999) “Sucrose analgesia”: absorptive mechanism or taste perception? Arch Dis Child Fetal Neonatal Ed 80:F146–F147
Beedie CJ, Stuart EM, Coleman DA, Foad AJ (2006) Placebo effects of caffeine on cycling performance. Med Sci Sports Exerc 38:2159–2164
Benedetti F, Dogue S (2015) Different placebos, different mechanisms, different outcomes: lessons for clinical trials. PLoS ONE 10:e0140967
Beedie C, Foad A, Hurst P (2015) Capitalizing on the Placebo Component of Treatments. Current Sports Med Rep 14:284–7
Halson SL, Martin DT (2013) Lying to win-placebos and sport science. Int J Sports Physiol Perform 8:597–599
Gaskell SK, Snipe RMJ, Costa RJS (2019) Test re-test reliability of a modified visual analogue scale assessment tool for determining incidence and severity of gastrointestinal symptoms in response to exercise stress. Int J Sports Nutr Exerc Metab 29:411–419
Newcomb RD, Xia MB, Reed DR (2012) Heritable differences in chemosensory ability among humans. Flavour 1:9. https://doi.org/10.1186/2044-7248-1-9
Pickering C, Kiely J (2018) What should we do about habitual caffeine use in athletes? Sports Med 49(6):833–842. https://doi.org/10.1007/s40279-018-0980-7
Guest N, Corey P, Vescovi J, El-Sohemy A (2018) Caffeine, CYP1A2 genotype, and endurance performance in athletes. Med Sci Sports Exerc 50:1570–1578
Loy BD, O'Connor PJ, Lindheimer JB, Covert SF (2015) Caffeine is ergogenic for adenosine a 2AReceptor gene (ADORA2A) T Allele homozygotes: a pilot study. J Caff Res 5:73–81
Søberg S, Sandholt CH, Jespersen NZ, Toft U, Madsen AL, von Holstein-Rathlou S et al (2017) FGF21 is a sugar-induced hormone associated with sweet intake and preference in humans. Cell Metab 25:1045–1046
Han P, Keast RSJ, Roura E (2017) Salivary leptin and TAS1R2/TAS1R3 polymorphisms are related to sweet taste sensitivity and carbohydrate intake from a buffet meal in healthy young adults. Br J Nutr 118:763–770
Key FM, Abdul-Aziz MA, Mundry R, Peter BM, Sekar A, D’Amato M et al (2018) Human local adaptation of the TRPM8 cold receptor along a latitudinal cline. PLoS Genet 14:e1007298–e1007322