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The Science Behind The Turbo+ Range


Indoor turbo training sessions are typically characterised by hard, intense intervals interspersed with short duration rest periods. The nature of such sessions places a high demand on the need for adequate carbohydrate availability and result in a rapid rise in the production of lactate and subsequent increase in the acidity within the muscle itself(1). Furthermore, exercise capacity and performance are often reduced when exercising in hot conditions due to both elevated physiological strain and feelings of thermal discomfort(2-4). In fact, one of the main contributors to the early onset of fatigue in hot environments is enhanced feelings of discomfort and a perception of being hot and uncomfortable(2).


Menthol acts to target thermoreceptors within the mouth to evoke pleasant and refreshing sensations and subsequently improves the ability to tolerate hot environments by reducing thermal perception(5,6) whilst also making it easier to breathe(7). Through these mechanisms, menthol consumption during exercise results in reduced perception of effort and improvements in both time trial and time to exhaustion exercise performance(5-10).

Exercise in the heat also increases the reliance on carbohydrate as a fuel(11) and, as such, the combination of menthol and carbohydrate within Turbo+ Powder provide both a cooling and energy benefit. Turbo+ Powder is also designed to be used as a mouth rinse and drink strategy as carbohydrate has the ability to stimulate receptors within the mouth(12) which have a stimulatory effect on the central nervous system (CNS) and ultimately enhance exercise performance(12-14).

Furthermore, given that indoor turbo sessions are synonymous with high-intensity intervals, Turbo+ Gel is formulated with a blend of caffeine, beta-alanine and L-carnitine so as to enhance performance. Caffeine enhances performance through its stimulatory effects on the central nervous system (CNS), whereas beta-alanine and L-carnitine facilitate improved muscle buffering, given the rapid rise in lactate accumulation and subsequent increase in muscle acidity associated with high-intensity efforts(1). Collectively, all three ingredients have the ability to enhance exercise performance(15-17).


The SiS Turbo+ range has been formulated to collectively meet the in-session fuelling and hydration requirements of high-intensity efforts whilst helping to combat the increased thermal stress that occurs with performing such sessions indoors. Furthermore, the pre-session Turbo+ Gel delivers key ingredients to maximise focus and performance as well as buffering against fatigue.

Pre-session Turbo+ Gel: 22g Carbohydrate, 150mg Caffeine

In Session Turbo+ Powder: 60g Carbohydrate, Isotonic & pH Neutral, Menthol flavouring




  • Stepto NK, Martin DT, Fallon KE, Hawley JA (2001). Metabolic demands of intense aerobic interval training in competitive cyclists. Med Sci Sports Exerc 33: 303-310.
  • Schlader ZJ, Simmons SE, Stannard SR, Mundel T (2011). The independent roles of temperature and thermal perception in the control of human thermoregulatory behaviour. Physiol Behav 103: 217-224.
  • Galloway SD, Maughan RJ (1997). Effects of ambient temperature on the capacity to perform prolonged cycle exercise in man. Med Sci Sports Exerc 29:1240–1249.
  • Tatterson AJ, Hahn AG, Martin DT, Febbraio MA (2000). Effects of heat stress on physiological responses and exercise performance in elite cyclists. J Sci Med Sport 3:186–193.
  • 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.
  • 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 notice slurry ingestion. Scand J Med Sci Sports 26: 1209-1216.e
  • Mundell T, Jones DA (2010). The effects of swilling an L(-)-menthol solution during exercise in the heat. Eur J Appl Physiol 109: 59-65.
  • Stevens CJ, Bennett, KJM, Sculley DV, Callister R, Taylor L, Dascombe BJ (2017). A comparison of mixed-method cooling interventions on preloaded running performance in the heat. J Strength Cond Res 31: 620-629.
  • 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.
  • Riera F, Trong TT, Sinnaph S, Hue O (2014). Physical and perceptual cooling with beverages to increase cycle performance in a tropical climate. PLoS One 9: e103713.
  • Febbraio MA, Snow RJ, Stathis CG, Hargreaves M, Carey MF (1994). Effect of heat stress on muscle energy metabolism. J Appl Physiol 77: 2827-2831.
  • Chambers ES, Bridge MW, Jones DA (2009). Carbohydrate sensing in the human mouth: effects on exercise performance and brain activity. J Physiol 587: 1779-1794.
  • Carter JM, Jeukendrup AE, Jones DA (2004). The effect of carbohydrate mouth rinse on 1-h cycling time trial performance. Med Sci Sports Exerc 36: 2107-2111.
  • Rollo I, Williams C, Gant N, Nute M (2008). The influence of carbohydrate mouth rinse on self-selected speeds during a 30-min treadmill run. Int J Sport Nutr Exerc Metab 18: 585-600.
  • Lane SC, Areta JL, Bird SR, Coffey VG, Burke LM, Desbrow B, Karagounis LG, Hawley JA (2013). Caffeine ingestion and cycling power output in a low or normal muscle glycogen state. Med Sci Sports Exerc 48: 1577-1584.
  • Van Thienen R, Van Proeyen K, Eynde BV, Puype J, Lefere T, Hespel P (2009). Beta-alanine improves sprint performance in endurance cycling. Med Sci Sports Exerc 41: 898-903.
  • Wall BT, Stephens FB, Constantin-Teodosiu D, Marimuthu K, Macdonald IA, Greenhaff PL (2011). Chronic oral ingestion of L-carnitine and carbohydrate increases muscle carnitine content and alters muscle fuel metabolism during exercise in humans. J Physiol 589: 963-973.
Written By

Professor James Morton

A professor of Exercise Metabolism at Liverpool John Moores University (LJMU) and a Registered Sports and Exercise Nutrition Practitioner with the British Dietetic Association’s UK Sport and Exercise Nutrition Register (SENr), James is responsible for research and innovation at Science in Sport, overseeing the Performance Solutions Team.