Wednesday, April 12, 2017

Study Puts Taurine Back in the Limelight - Sprint Cycling in Trained Athletes Benefits from Taurine, not Caffeine!?

More evidence that the often high taurine content in your energy drinks is more than a mere marketing gag.
You will probably remember my recent article about the potentially underestimated contribution of taurine to the performance enhancing effects of Red Bull™ and co. (read it again). Now, a new study from the School of Sport, Health and Applied Science at the St Mary’s University in Great (soon small) Britain shows: Only taurine, yet not caffeine boosts the sprint cycling performance in trained athletes. And as if that wasn't enough, yet, the study also proves another benefit of taurine I've written about in the past: it reduces the typical (negative) side effects of high(er)-dose caffeine.
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For their study, the researchers from the UK who were supported by colleagues from Australia recruited seven male team sports players (age 20.8 ± 0.9 years; stature 1.76 ± 0.11 m; body mass 86.3 ± 10.2 kg). Despite the small sample size, the scientists' a priori calculation indicated that a sample size of seven was sufficient to identify differences between groups with a statistical power of 0.80.

The subjects were randomized, in a single-blind design to perform three Wingate tests, each separated by 2-min, an hour after ingesting
  • caffeine (C) at a dosage of  5 mg/kg body mass,
  • taurine (T) at a dosage of 50 mg/kg BM, 
  • caffeine and taurine (C+T) at dosages of 5 mg/kg BM + 50 mg/kg, respectively, or 
  • placebo capsules (P) with an identical look and weight
before being crossed over three follow-up experiment in which the subjects would consume one of the other treatments.
Figure 1: Taurine turns out to be the great fatigue modulator - if it's consumed w/out caffeine (Warnock 2017).
The subjects' performance was measured on an ergometer, whilst blood lactate, perceived exertion, heart rate (HR), mean arterial pressure (MAP) and rate pressure product (RPP) were measured at rest (pre-supplement), baseline (1-h post-supplement) and during and after exercise; and the results I plotted in Figure 1 speak for themselves.
A 2004 study by Miyazaki et al found dose-dependent increases in endurance w/ human eq. doses of ~0.25g, ~1,25g and ~6.25g of taurine.
You probably need more taurine, bro: The top dog in the energy drink market contains 2g taurine, which is more than you will find in many of the cheap copy cats, but less 50mg/kg for most of you. Accordingly, the study at hand the previously discussed meta-analysis of the ergogenic prowess of energy drinks and an older rodent study by Miyazaki et al (2004 | see Figure on the left) indicate that "more helps more" and thus suggest that many of the previously conducted studies, as well as your own efforts, could have failed to yield results because you didn't get to the ergogenic threshold which may be at 4-5g+.
In view of the relatively small study group, the scientists conducted a magnitude-based inference analysis to get to the bottom of the relevance of the effects they observed and found that...
  • all of the supplements increased (small to moderate, likely to very likely) mean peak power (MPP), peak power (PP) and mean power (MP) compared to P, with greater MPP, PP and MP in T compared to C (small, possible)
  • intra-sprint fatigue index (%FIIntra) was greater in the taurine (T) compared to placebo (P) and control (C) group - the practical relevance of this difference does yet appear to be smaller than that of the albeit likewise small decreased inter-sprint fatigue index (%FIInter) in the taurine (T) compared to the caffeine (C) group
  • C and C+T increased HR, MAP and RPP compared to P and T at baseline (moderate to very large, likely to most likely); however, these only remained higher in C compared to all conditions in the final sprint.
What? Ok, let's simplify that a bit by taking a look at the plot of the fatigue and performance data in Figure 1 & 2 again. These graphs clearly reveal that (A) there was a sign. performance increase with all three supplements (Figure 2). Only the taurine (only) trial, however, (B) reduced the inter-sprint fatigue index (Figure 1) which appears to be the fatigue marker with greater relevance for most sports that require intermittent sprints.
Figure 2: The performance increases were virtually identical in all three supplement groups (Warncock 2017).
Accordingly, the practical implication is that using taurine, alone, may be the better choice for cyclists and other athletes whose sports involve short all-out sprints - the overall inter-group differences however are small and further research is warranted before one could make any definitive recommendations with respect to the combined or individual use of caffeine and taurine.

Taurine is probably at least as much a health as performance supplement

Figure 3: Possible mechanisms responsible for beneficial effect of taurine in prevention and amelioration of metabolic syndrome (Murakami 2013).
What I would like to repeat, though, is that taurine has not just been found to have (a) cytoprotective effects against exercise-induced muscle injury (Dawson 2002; da Silva 2013), (b) limit oxidative stress in skeletal muscle (Silva 2011).

Taurine (supplementation) has also been found to have sign. health benefits (Militante 2004) in obesity-induced hyperlipidemia (Zhang 2004), to keep homocysteine and thus heart disease risk in check (Ahn 2009), to reverse endothelial dysfunction in high risk groups, like young type I diabetics (Moloney 2010) or to be useful in the treatment of non-alcoholic fatty-liver disease (Gentile 2011).

Furthermore, many scientists believe that its supplementation or high dietary intakes could be usfeful in the prevention of diabetes and metabolic syndrome (Murakami 2013; Imae 2014).
A recent meta-analysis of all studies that investigate the performance enhancing effects of energy drinks supports the notion that taurine is much more important for their beneficial effects on your performance than caffeine | read more
So, taurine only it is? If that's the take home message you remember, you have a problem... at least if your sport does not require only short bursts of all out sprinting. Caffeine has previously been shown to excel in long(er) duration exercise (Denadai 1998; Ganio 2009); and while further research is clearly indicated these observations imply that a combination of both taurine and caffeine may be the best choice for all athletes whose sports involve long(er) and/or low(er) intensity intervals of physical activity, where the beneficial effects of taurine on the subjects' heart rate, mean arterial pressure and pressure product may come handy especially but not exclusively for people with cardiovascular problems | Comment on the SuppVersity Facebook Page!
References:
  • Ahn, Chang Soon. "Effect of taurine supplementation on plasma homocysteine levels of the middle-aged Korean women." Taurine 7. Springer New York, 2009. 415-422.
  • Dawson, Jr, R., et al. "The cytoprotective role of taurine in exercise-induced muscle injury." Amino acids 22.4 (2002): 309-324.
  • Denadai, B. S., and M. L. D. R. Denadai. "Effects of caffeine on time to exhaustion in exercise performed below and above the anaerobic threshold." Brazilian journal of medical and biological research 31.4 (1998): 581-585.
  • Ganio, Matthew S., et al. "Effect of caffeine on sport-specific endurance performance: a systematic review." The Journal of Strength & Conditioning Research 23.1 (2009): 315-324.
  • Gentile, Christopher L., et al. "Experimental evidence for therapeutic potential of taurine in the treatment of nonalcoholic fatty liver disease." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 301.6 (2011): R1710-R1722.
  • Imae, Masato, Toshiki Asano, and Shigeru Murakami. "Potential role of taurine in the prevention of diabetes and metabolic syndrome." Amino Acids 46.1 (2014): 81-88.
  • Moloney, Michael A., et al. "Two weeks taurine supplementation reverses endothelial dysfunction in young male type 1 diabetics." Diabetes and Vascular Disease Research 7.4 (2010): 300-310.
  • Militante, Julius D., and John B. Lombardini. "Dietary taurine supplementation: hypolipidemic and antiatherogenic effects." Nutrition Research 24.10 (2004): 787-801.
  • Miyazaki, T., et al. "Optimal and effective oral dose of taurine to prolong exercise performance in rat." Amino acids 27.3 (2004): 291-298.
  • Murakami, S., and Y. Yamori. "Taurine and Longevity–Preventive Effect of Taurine on Metabolic Syndrome." Bioactive Food as Dietary Interventions for the Aging Population (2013): 159.
  • Silva, Luciano A., et al. "Taurine supplementation decreases oxidative stress in skeletal muscle after eccentric exercise." Cell biochemistry and function 29.1 (2011): 43-49.
  • da Silva, Luciano A., et al. "Effects of taurine supplementation following eccentric exercise in young adults." Applied Physiology, Nutrition, and Metabolism 39.1 (2013): 101-104.
  • Warnock, Rory, et al. "The Effects of Caffeine, Taurine or Caffeine-Taurine Co-Ingestion on Repeat-Sprint Cycling Performance and Physiological Responses." International Journal of Sports Physiology and Performance (2017): 1-24.
  • Zhang, M., et al. "Beneficial effects of taurine on serum lipids in overweight or obese non-diabetic subjects." Amino acids 26.3 (2004): 267-271.