The Bitter Taste that Gets You Going: Quinine Mouthrinse Provides Instant 4% Power Boost During 30s All-Out Sprint

The Bitter Taste that Gets You Going: Quinine Mouthrinse Provides Instant 4% Power Boost During 30s All-Out Sprint

ergogenic mean power mouthrinse peak power performance power powerlifting quinine sprinting sprints

Getting ready for an all-out sprint? A bitter mouth rinse W/ quinine will provide instant power boost of 4% in ‘ur 30s cycle sprint more than a sweet mouth rinse could do .

If you're a powerlifter, the idea that rinsing your mouth with a bitter substance can improve your performance is probably no news for you... even though, powerlifters smell, not taste ammonia, smelling and tasting are, after all, more or less two sides of the same coin (Rozin. 1982).

Against that background and in view of the similar brain activation patterns scientists have observed in response to bitter and sweet taste perception, it appears only logical for Sharon Gam et al. to speculate in a 2014 paper, which is still worth its own SuppVersity article (!), that rinsing w/ quinine, a distinctly bitter substance, could produce the same or at least similar power increments as sweet substances.

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Of the latter, previous research has shown that they will elevate both peak power (+22.1 ± 19.5 W; ES, 0.81; p = 0.0667) and mean power (+39.1 ± 26.9 W; ES, 1.08; p = 0.0205 | Beaven, et al. 2013), during all out sprints. The goal of the researchers from the University of Western Australia was thus to elucidate, "whether combining mouth rinsing with the ingestion of a bitter-tasting solution composed of quinine acutely improves mean and peak power during a 30-s maximal cycling sprint effort" (Gam. 2016) would yield similar benefits.

To be able to tell how similar sweet and bitter taste effects on sprinting performance actually are, they scientists compared the effects of 0.36 mL/kg body mass of a 2-mM quinine HCl solution (QUI; Sigma-Aldrich), not just to plain water and a no rinse control (CON), but also to a 0.05% w/v aspartame solution (ASP; Sigma-Aldrich), all of which were used immediately before the 30s all-out sprint on an Exertech EX-10 front access cycle ergometer.

Figure 1: My graphical "illustration" of the study design (based on facts from Gam. 2014).

As the authors explain, the "volume of 0.36 mL/kg was chosen to account for differences in body size, with each participant receiving approximately 25–35 mL of solution per session" (Gam. 2014) and the "[p]articipants were instructed to rinse their mouth for 10 s and then ingest the solution", a practice that was prescribed to ensure "that bitter receptors at the back of the tongue were activated because there is evidence that the strongest sensation of bitterness occurs in that area of the oral cavity" (Gam. 2014).

Bitter perception (Mennella. 2013).

Have you ever asked yourself how "bitter works"? Here is the answer from a 2013 paper by Mennella, et al. → "The generation of bitter taste starts when a bitter compound enters the oral cavity, where the ligand binds to a T2R G-protein coupled receptor expressed in the apical membrane of receptor cells found in taste buds, triggering a cascade of signaling events, leading to the release of neurotransmitter that activates an afferent nerve fiber that transmits the signal via the cranial nerve to the brain. Taste buds are distributed in distinct fields in the oral, pharyngeal, and laryngeal epithelia, with each field innervated by a different cranial nerve branch. Only the taste buds on the tongue are depicted in the figure."

As you can see in the selected performance markers I've plotted for you in Figure 2, the fourteen competitive male cyclists, who performed a 30-s maximal cycling sprint immediately after rinsing their mouth for 10 s and then ingesting the aforementioned solutions (QUI, water, ASP, CON), experienced significant increases in both mean power output by 2.4%–3.9% [P < 0.021, effect size (ES) = 0.81–0.85] and peak power output in the quinine condition.

Figure 2: Relative changes in mean & peak power (%) + effects sizes for quinine vs. CON, WAT or ASP (Gam. 2014).

For the latter, it is yet important to point out that a significant performance enhancement in terms of the peak power output was recorded only in comparison to the water (3.7%, P = 0.013, ES = 0.71) and the control (3.5% P = 0.021, ES = 0.84) conditions, yet not compared to the aspartame condition (1.9%, P = 0.114, ES = 0.47), in which the scientists observed a non-significant increase in performance compared to the water and control trial. Differences in heart rate, perceived exertion, or blood variables between any of the conditions were not observed.

Bitter taste increases ghrelin, ghrelin rapidly increases noradrenaline and adrenaline - if that's what explains the effects of quinine will yet have to be elucided in future studies.

So what's the mechanism, here? Unfortunately, the researchers don't speculate about the mechanism behind this, for sprinters and power athletes highly relevant effect of quinine (or other bitter tastants). My brief research of the existing research on bitter taste receptors, however, suggests various possible mechanisms with the release of ghrelin in response to bitter taste sensing (Janssen. 2011) and its effects on gluconeogenesis, noradrenaline and adrenaline (Enomoto. 2003 | see Figure on the right) being a candidate that would usually have us expect to see more pronounced increases in heart rate than they were observed in the study at hand, where quinine raised the heart rate only in the absence of exercise (by ~3-4 bpm).

It is thus questionable, whether the ghrelin => (nor-)adrenaline hypothesis provides the correct explanation - not just, but also because previous research suggests that the benefits of rinsing your mouth with bitter substances before sprinting may have the same origin as those that occur in response to carbohydrate mouth-rinsing, the triggers of which are likewise believed to "reside in the central nervous system" (Jeukendrup. 2010) and thus to be of non-metabolic origin.

Since the quinine solution was also swallowed, effects that were triggered by bitter taste receptors (ghrelin remains the most likely candidate) in endocrine cells along the gut (figure from Depoortere. 2014) could also explain the performance increases.

Speaking of carbohydrate / sweet mouth rinses, it should be mentioned that the lack of significant performance differences (1.9%, P = 0.114, ES = 0.47) between the aspartame and the quinine trial in the study at hand appears to suggest that sweet and bitter mouth rinses work by the same, still to be elucidated mechanism (it should be said, though that structural analogues of aspartame have been found to active the bitter taste receptor, as well | Benedetti. 1995).

In view of the fact that this hypothesis is, as Gam et al. point out, in line with the results of "studies based on functional magnetic resonance imaging [, which] have shown that the brain areas activated in response to the bitter tastant, quinine, overlap to a great extent" with those brain areas that are stimulated when you rinse with CHOs / sweet solutions (Zald. 2002; Small. 2003), finding mechanistic explanations for one of these performance enhancer (e.g. the sweet mouthrinse) may also yield explanations for the performance enhancing effects of the other one. Whether that's the actual reason for the preformance increases does yet appear questionable. After all, a 2015 follow up study by the same researchers showed that that mouth rinsing with the same bitter quinine solution without ingesting it won't improve young athletes' sprint cycling performance (Gam. 2015) - in view of the presence of ghrelin producing cells in the digestive tract (see Figure in this bottom line), this does not falsify the "ghrelin" => (nor-)adrenaline hypothesis, which would also be in line with the increases in corticomotor excitability Gam et al. observed in yet another follow up study in male competitive cyclists (Gam. 2015b), in which the quinine was ingested, too | Comment!

References:

• Beaven, C. Martyn, et al. "Effects of caffeine and carbohydrate mouth rinses on repeated sprint performance." Applied Physiology, Nutrition, and Metabolism 38.6 (2013): 633-637.
• Benedetti, Ettore, et al. "Sweet and bitter taste: Structure and conformations of two aspartame dipeptide analogues." Journal of Peptide Science 1.6 (1995): 349-359.
• Depoortere, Inge. "Taste receptors of the gut: emerging roles in health and disease." Gut 63.1 (2014): 179-190.
• Enomoto, Mitsunobu, et al. "Cardiovascular and hormonal effects of subcutaneous administration of ghrelin, a novel growth hormone-releasing peptide, in healthy humans." Clinical Science 105.4 (2003): 431-435.
• Gam, Sharon, Kym J. Guelfi, and Paul A. Fournier. "Mouth rinsing and ingesting a bitter solution improves sprint cycling performance." Medicine and science in sports and exercise 46.8 (2014): 1648-1657.
• Gam, Sharon, et al. "Mouth rinsing with a bitter solution without ingestion does not improve sprint cycling performance." European journal of applied physiology 115.1 (2015a): 129-138.
• Gam, Sharon, et al. "Mouth rinsing and ingestion of a bitter-tasting solution increases corticomotor excitability in male competitive cyclists." European journal of applied physiology 115.10 (2015b): 2199-2204.
• Janssen, Sara, et al. "Bitter taste receptors and α-gustducin regulate the secretion of ghrelin with functional effects on food intake and gastric emptying." Proceedings of the National Academy of Sciences 108.5 (2011): 2094-2099.
• Jeukendrup, Asker E., and Edward S. Chambers. "Oral carbohydrate sensing and exercise performance." Current Opinion in Clinical Nutrition & Metabolic Care 13.4 (2010): 447-451.
• Rozin, Paul. "“Taste-smell confusions” and the duality of the olfactory sense." Attention, Perception, & Psychophysics 31.4 (1982): 397-401.
• Small, Dana M., et al. "Dissociation of neural representation of intensity and affective valuation in human gustation." Neuron 39.4 (2003): 701-711.
• Zald, David H., Mathew C. Hagen, and José V. Pardo. "Neural correlates of tasting concentrated quinine and sugar solutions." Journal of Neurophysiology 87.2 (2002): 1068-1075.

Mo, We, Fr - Sequence of Hypertrophy, Power & Strength Will Up Your Gains on the Big Three (Squat, Bench, Deadlift)

Mo, We, Fr - Sequence of Hypertrophy, Power & Strength Will Up Your Gains on the Big Three (Squat, Bench, Deadlift)

ADP athletes bench press build strength deadlift DUP performance periodization powerlifting resistance training squat training programming training programs UDP

Squat, bench press, deadlift - All major three benefit from the right order in your daily undulating periodization program (DUP) - This is how it works...

As a SuppVersity reader you are familiar with the term "undulating periodization". In contrast to regular periodization schemes, undulating schemes will have you train in different rep ranges on a weekly or - as in the latest study by Zourdos et al. (2016), even daily (as in every workout) basis.

As Zourdos, et al. point out, the available research shows mixed results with the respect to the efficacy of regular linear vs. undulating periodization schemes. While some studies report no differences among training models (Baker. 1994; Buford. 2007; Kok. 2009), others suggest that the more frequent changes of the rep ranges in an undulating periodization scheme are more advantageous for strength development (Miranda. 2011; Monteiro. 2009; Peterson. 2008; Prestes. 2009; Rhea. 2002).

The method used int he study is an alternative to classic periodization schemes.

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When you take a closer look at the data, one of the potential confounding factors that emerges is the subjects' training experience with no significantly distinct advantages in untrained or recreationally trained individuals (Baker. 1994; Buford. 2007; Herrick. 1999; Kok. 2009) and a significantly greater degree of muscular strength development when using a DUP design compared with LP (Miranda. 2011; Monteiro. 2009; Peterson. 2008; Prestes. 2009; Rhea. 2002). An alternative difference, the effects of which have not been investigated yet, are programming variations within the daily undulating periodization (DUP) framework in experienced athletes. More specifically, ...

"[i]t is reasonable to speculate that the program design and practical implementation of DUP can be further optimized. A possible area of improvement in the DUP design is the temporal configuration of hypertrophy-centric, strength-centric, and power/speedcentric sessions within a given week. Previous research demonstrating the effectiveness of DUP over LP implemented a weekly training order of hypertrophy-centric, strength-centric, and power-centric bouts (e.g., hypertrophy training on Monday, strength training on Wednesday, and power training on Friday) (Peterson. 2008). However, this design calls for a strength-centric bout to be performed just 48–72 hours after a hypertrophy-centric bout each week. Hypertrophy training is characterized by sessions of high volume of exercise, a condition shown to result in heightened muscle damage, and compromised neuromuscular performance for up to 48-hour postexercise (Flann. 2011; Rhea. 2002b). In the context of traditional DUP formatting, this may conceivably hinder performance (i.e., total volume [TV] performed) during the subsequent strength-centric bout, thereby precluding strength athletes from maximizing their training potential" (Zourdos. 2016).

To investigate the potential negative effects of hypertrophy training induced muscle damage on the subsequent strength training bout, Zourdos et al. (2016) compared the effects of a modified DUP format with a weekly training order of hypertrophy-centric (H), power-centric (P), and strength-centric bouts (S | H-P-S) on total training volume (i.e., sets 3 reps 3 weightlifted) and muscular strength in comparison with a traditional DUP model (i.e., HSP) in resistance-trained men for 6 weeks (see Figure 1).

Table 1: Experimental training periodization - Traditional Daily Undulating Periodization (DUP) involves a weekly training order of hypertrophy, strength, and then power focused bouts (HSP). Modified DUP involves a weekly training order of hypertrophy, power, and then strength focused bouts. Each protocol spans 6 weeks and consists of three exercises: back squat, bench press, and deadlift (only performed during strength-centric bouts | Zourdos. 2016).

In order to find out what could be responsible for any potentially observable differences in their study, the authors also tested the total training volume as measured by the total poundage the subjects moved during the strength sessions, in which the subjects trained to failure, and the temporal secretion patterns of testosterone and cortisol in response to both DUP training programs.

Understanding the benefits: Since I've already received questions about how the benefits came about, let me briefly elaborate on the idea of HPS vs. HSP. The notion was that <48h of recovery, from Monday to Wednesday, after a higher volume hypertophy (H) training program would not be enough to hit personal bests on the strength day on which - and that's important - the subjects had to perform each set to full failure. If you train to failure, recovery is a crucial determinant of the number of reps you will master and thus the total volume. The latter, in turn, appears to be one of the central determinants of the strength / hypertrophy response to resistance training, which in turn makes you stronger and will allow you to lift even more weight. So, postponing the strength (S) day to Friday instead of Wednesday will have both, direct and indirect beneficial effects on your gains.

In that, Zourdos, et al. hypothesized that "HPS (i.e., modified DUP) would yield greater volume and strength gains in the 3 exercises performed during training" (Zourdos. 2016).

Figure 1: Rel. change in strength and abs. Cohen’s d effect size in HSP and HPS groups (N = 9 for both; Zourdos. 2016).

As you can see in Figure 1, the scientists were right, the effects of the otherwise identical training protocols, which involved 3 exercises (squats + bench presses in every, deadlifts only in the strength sessions) during training, of which the subjects did ..

• 5 sets of 8 reps at 75% 1RM during H = hypertrophy,
• 5 sets of 1 rep at 80%-90% increased every 2 weeks during P = power and
• 3 sets to failure at 85% during S = strength raining

differed significantly, with a statistical significant advantage on the bench and meaningfully higher effect sizes for all three exercises in the HPS group - an effect that could be mediated by the increased total volume and Wilk's coefficient, a measure that can be used to measure the strength of a powerlifter against other powerlifters despite the different weights of the lifters (see Figure 2).

Figure 2: Rel. change in powerlifting volume and Will's coefficient + effect sizes in HSP and HPS groups (Zourdos. 2016).

An alternative explanation of which previous studies do yet not confirm that it may explain the difference is the differential cortisol / testosterone response (learn more) - in view of the fact that the difference you see in Table 2 is not statistically significant, though, it is even more unlikely that the meager difference in testosterone and cortisol the scientists observed had any effect.

Table 1: Pre- and post-training serum testosterone and cortisol level (Zourdos. 2016).

Against that background, we're back to the "usual" subject, when it comes to determinants of the degree of adaptation to resistance training: volume - the same parameter reviews and studies by Schoenfeld et al. (2010; 2011; 2014) have previously singled out as the (most important) determinant of training success.

Again: The differences in the cortisol / testosterone levels were not just statistically non-significant. At least the latter has also been shown to have no effect on your gains, anyways | more.

Bottom line: As the authors point out, "[t]hese findings demonstrate 2 important factors in accordance with the previous literature: (a). Total training volume seems to be a determinant of increased strength performance, and (b). Daily undulating periodization is an effective model to
enhance 1RM strength during short-term training protocols in well-trained men" (Zourdos. 2016).

Zourdos et al. are yet also right to point out that few training studies exist regarding various training designs. This alone warrants further "research examining further DUP configurations is necessary" - studies in less trained individuals, and studies investigating the size gains, too could after all both yield different results for the same H-S-P to H-P-S comparison | Comment on Facebook!

References:

• Baker, Daniel, Greg Wilson, and Robert Carlyon. "Periodization: The Effect on Strength of Manipulating Volume and Intensity." The Journal of Strength & Conditioning Research 8.4 (1994): 235-242.
• Buford, Thomas W., et al. "A comparison of periodization models during nine weeks with equated volume and intensity for strength." The Journal of Strength & Conditioning Research 21.4 (2007): 1245-1250.
• Flann, Kyle L., et al. "Muscle damage and muscle remodeling: no pain, no gain?." The Journal of experimental biology 214.4 (2011): 674-679.
• Herrick, Andrew B., and William J. Stone. "The Effects of Periodization Versus Progressive Resistance Exercise on Upper and Lower Body Strength in Women." The Journal of Strength & Conditioning Research 10.2 (1996): 72-76.
• Kok, Lian-Yee, Peter W. Hamer, and David J. Bishop. "Enhancing muscular qualities in untrained women: linear versus undulating periodization." Med Sci Sports Exerc 41.9 (2009): 1797-807.
• Miranda, Fabrício, et al. "Effects of linear vs. daily undulatory periodized resistance training on maximal and submaximal strength gains." The Journal of Strength & Conditioning Research 25.7 (2011): 1824-1830.
• Monteiro, Artur G., et al. "Nonlinear periodization maximizes strength gains in split resistance training routines." The Journal of Strength & Conditioning Research 23.4 (2009): 1321-1326.
• Peterson, Mark D., et al. "Undulation training for development of hierarchical fitness and improved firefighter job performance." The Journal of Strength & Conditioning Research 22.5 (2008): 1683-1695.
• Prestes, Jonato, et al. "Comparison of linear and reverse linear periodization effects on maximal strength and body composition." The Journal of Strength & Conditioning Research 23.1 (2009): 266-274.
• Rhea, Matthew R., et al. "A comparison of linear and daily undulating periodized programs with equated volume and intensity for strength." The Journal of Strength & Conditioning Research 16.2 (2002a): 250-255.
• Rhea, Matthew R., et al. "Three sets of weight training superior to 1 set with equal intensity for eliciting strength." The Journal of Strength & Conditioning Research 16.4 (2002b): 525-529.
• Schoenfeld, Brad J. "The mechanisms of muscle hypertrophy and their application to resistance training." The Journal of Strength & Conditioning Research 24.10 (2010): 2857-2872.
• Schoenfeld, Brad. "The use of specialized training techniques to maximize muscle hypertrophy." Strength & Conditioning Journal 33.4 (2011): 60-65.
• Schoenfeld, Brad J., et al. "Effects of different volume-equated resistance training loading strategies on muscular adaptations in well-trained men." The Journal of Strength & Conditioning Research 28.10 (2014): 2909-2918.