3g Taurine Improve Post-Workout Glycogen Resynthesis, Protect the Testes of Doping Sinners & Battles Alzheimer's

Taurine - A useful supplement for chemical, natural athletes and even sedentary slobs who are afraid of diabetes.

Taurine, or 2-aminoethanesulfonic acid, as Wikipedia says, is an organic acid widely distributed in animal tissues. It is a major constituent of bile and can be found in the large intestine, and accounts for up to 0.1% of total human body weight. That does not sound like much, but taurine has many fundamental biological roles, such as conjugation of bile acids, antioxidation, osmoregulation, membrane stabilization, and modulation of calcium signaling. It is essential for cardiovascular function, and development and function of skeletal muscle, the retina, and the central nervous system and you were thus probably not too surprised, when you've recently read on the SuppVersity Facebook Page that taurine may help with Alzheimer's disease.
In the corresponding paper that was published only recently in the ScientificReports on Nature.com Kim et al. report that orally administered taurine via drinking water rescued the cognitive deficits in a standard rodent model of Alzheimer's (APP/PS1 mice) and brought them back up to age-matching wild-type mice.

Figure 1: Improvement in spatial and hippocampal learning behaviours in taurine-treated transgenic mice. 7-month old wild-type (Wt) and agematched APP/PS1 transgenic (Tg) male mice were orally administered water or taurine (1,000 mg/kg/day) for 6 weeks (n 5 8–10 per group). After 6 weeks, behavioural tests were administered to the 8.5-month old mice. (Left) Y-maze. Average alternation (%) of each group of mice was calculated. (Right) Passive avoidance. Average latency time in seconds for each group of mice was measured (Kim. 2014).

That's unquestionably impressive, but what's more impressive is that this is by far not the first study to report that taurine exhibits a plethora of physiological functions in the central nervous system.
In a recent review in the scientific journal Amino Acids review, Janet Menzie et al. describe the mode of action of taurine and its clinical application in the neurological diseases: Alzheimer’s disease, Parkinson’s disease and Huntington’s disease and conclude that taurine...

"[...] functions through multiple neuroprotective mechanisms: regulation of cellular osmolarity , anti-oxidant, neuromodulator of GABAergic transmission, maintenance of calcium homeostasis, inhibition of glutamate excitotoxicity, attenuation of endoplasmic reticulum stress, modulation of mitochondrial pore permeability, downregulation of a range of proapoptotic proteins while upregulating anti-apoptotic proteins and downregulation of inflammatory mediators." (Menzie. 2014)

Moroever, Menzie et al. believe that there is "strong evidence" of the existence of a specific taurine receptor, which is activated exclusively by taurine, but not by structurally similar amino acids such as glutamate, GABA and glycine and could be responsible for many of the beneficial effects taurine exerts in the context of central nervous system disorders. More specifically existing evidence clearly suggests protective effects in Alzheimer’s, Parkinson and Huntington diseases. Three pathologies that share a number of broad mechanisms: Oxidative stress, mitochondrial dysfunction, excitotoxicity, calcium imbalance, inflammatory changes apoptosis - and *tadaa* a reduced level of (Arai. 1985; Alom. 1991; Molina. 1997).

Enough of the health stuff, what about the post-workout goodness?

I know, as long as we are healthy we don't really care about debilitating central nervous system disorders... well, ok. I will spare you my moral pointing finger and get straight to the similarly unsurprising results of a recent study from the University of Tokyo. A study which clearly indicates that the provision of taurine after workouts can lead to a significant enhancement of the already elevated glycogen synthesis after your workouts.

Figure 2: Muscle and liver glycogen and serum free fatty acids (FFA) before and after the workout (Takahashi. 2014).

In two rodent studies, the Japanese researchers tested whether the oral administered of taurine  at a dosage of 0.5 g/kg body weight (for human beings that's 0.04g/kg or approximately 3g total | the SuppVersity suggested dose from previous articles, by the way) immediately after treadmill running at 25 m/ min for 90 min would alter the metabolic response and glycogen synthesis after workouts when it was (A) administered alone or (B) as part of a glucose solution containing taurine and glucose at a ratio of 1:2 - in this case 0.5g/kg taurine and 1.0g/kg glucose.

Figure 3: AUC for glucose after for 60min and 120min after the ingestion of the taurine + glucose solution. As the data indicates taurine helped to "clear" the sugar from the blood stream (Takahashi. 2014).

As the scientists point out, their "results show that post-exercise taurine administration enhances glycogen repletion in skeletal muscle" (Takahashi. 2014). The underling cause, however, is still speculative. Takahashi et al. believe that it is triggered by

1. Figure 4: Changes in general oxidative damage (TBARs), protein damage and exercise performance in response to taurine vs. placebo vs. bet alanine supplementation; expressed relative to untrained control (Dawson. 2002).

   an acceleration of glucose uptake, and
2. an increase in fat oxidation

of which the latter will have a carbohydrate sparing effect and will thus leave a higher amount of carbs for glycogen repletion. In conjunction with previously established benefits of taurine, such as

• the attenuation of exercise-induced DNA damage during workouts (young men | Zhang. 2004),
• the amelioration of cytotoxic (cell damaging) effects of exercise (rodents | Dawson. 2002),
• an increase in exercise performance (specifically endurance ex. | Dawson. 2002; Miyazaki. 2004),
• additional effects on the benefits of BCAA intake for the delayed-onset muscle soreness and muscle damage induced by high-intensity eccentric exercise (Ra. 2013),
• an improvement in osmoregulation (water balance) of the muscle (Cuisinier. 2002), and
• decreases in oxidative stress during eccentric exercises (Silva. 2011)

The optimal dosing for performance increments, by the way, is between 1.2-6.0g for 2 weeks (other timing has not been tested, so it's possible that one week will suffice, too). That's at least what the only hitherto published study that investigated the effects of different doses of taurine as a means to improve the endurance performance (Miyazaki. 2004). If you want the nutrient partitioning effects, though, you would have to consume CHO + taurine after the workout - 3g of taurine should suffice. Judged by the hitherto published studies this should automatically help you to increase your workout performance after 2 weeks (the beneficial effects will, just as it is the case for creatine, accumulate until the levels are saturated).

And there are more benefits - health benefits, for juicers and non-juicers

The former, i.e. the juicers will probably be happy to hear that taurine does not just have liver protective effects (Miyazaki. 2005), but will also reverse the nandrolone decanoate induced perturbations in sperm characteristics, normalize the serum testosterone level, and restore the activities of the key steroidogenic enzymes in rodents that are treated with nandrolone and taurine (at a dosage equivalent to only 1.3g/day | Ahmed. 2014).

In spite of the fact that the administration of taurine did also prevent the nandrolone decanoate-induced testicular toxicity and DNA damage by virtue of its antioxidant, anti-inflammatory, and anti-apoptotic effects, I would like to point out that this article is not intended as an incentive for nandrolone doping.
References:

• Ahmed, Maha AE. "Amelioration of Nandrolone Decanoate-Induced Testicular and Sperm Toxicity in Rats by Taurine: Effects on Steroidogenesis, Redox and Inflammatory Cascades, and Intrinsic Apoptotic Pathway." Toxicology and Applied Pharmacology (2014).
• Alom, J., et al. "Cerebrospinal fluid taurine in Alzheimer's disease." Annals of neurology 30.5 (1991): 735-735.
• Arai, Heii, et al. "A preliminary study of free amino acids in the postmorten temporal cortex from Alzheimer-type dementia patients." Neurobiology of aging 5.4 (1985): 319-321. 
• Carneiro, Everardo M., et al. "Taurine supplementation modulates glucose homeostasis and islet function." The Journal of nutritional biochemistry 20.7 (2009): 503-511.
• Cuisinier, Claire, et al. "Role of taurine in osmoregulation during endurance exercise." European journal of applied physiology 87.6 (2002): 489-495.
• Dawson Jr, R., et al. "The cytoprotective role of taurine in exercise-induced muscle injury." Amino acids 22.4 (2002): 309-324. 
• Franconi, Flavia, et al. "Taurine supplementation and diabetes mellitus." Current Opinion in Clinical Nutrition & Metabolic Care 9.1 (2006): 32-36.
• Haber, C. Andrew, et al. "N-acetylcysteine and taurine prevent hyperglycemia-induced insulin resistance in vivo: possible role of oxidative stress." American Journal of Physiology-Endocrinology and Metabolism 285.4 (2003): E744-E753.
• Han, Jin, et al. "Taurine increases glucose sensitivity of UCP2-overexpressing β-cells by ameliorating mitochondrial metabolism." American Journal of Physiology-Endocrinology and Metabolism 287.5 (2004): E1008-E1018. 
• Kim, Hye Yun, et al. "Taurine in drinking water recovers learning and memory in the adult APP/PS1 mouse model of Alzheimer's disease." Scientific Reports 4 (2014).
• Menzie, Janet, et al. "Taurine and central nervous system disorders." Amino acids 46.1 (2014): 31-46.
• Miyazaki, T., et al. "Optimal and effective oral dose of taurine to prolong exercise performance in rat." Amino Acids 27.3-4 (2004): 291-298.
• Miyazaki, Teruo, et al. "Taurine inhibits oxidative damage and prevents fibrosis in carbon tetrachloride-induced hepatic fibrosis." Journal of hepatology 43.1 (2005): 117-125.
• Molina, José A., et al. "Decreased cerebrospinal fluid levels of neutral and basic amino acids in patients with Parkinson's disease." Journal of the neurological sciences 150.2 (1997): 123-127.
• Nakaya, Yutaka, et al. "Taurine improves insulin sensitivity in the Otsuka Long-Evans Tokushima Fatty rat, a model of spontaneous type 2 diabetes." The American journal of clinical nutrition 71.1 (2000): 54-58.
• Oudit, Gavin Y., et al. "Taurine supplementation reduces oxidative stress and improves cardiovascular function in an iron-overload murine model." Circulation 109.15 (2004): 1877-1885.
• Rahman, Mizanur M., et al. "Taurine prevents hypertension and increases exercise capacity in rats with fructose-induced hypertension." American journal of hypertension 24.5 (2011): 574-581.
• Saad, Sherif Y., and Ammar C. Al-Rikabi. "Protection effects of taurine supplementation against cisplatin-induced nephrotoxicity in rats." Chemotherapy 48.1 (2010): 42-48.
• 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. 
• Takahashi, Yumiko, et al. "Post-exercise taurine administration enhances glycogen repletion in tibialis anterior muscle." The Journal of Physical Fitness and Sports Medicine 3.5 (2014): 531-537.
• Zhang, M., et al. "Role of taurine supplementation to prevent exercise-induced oxidative stress in healthy young men." Amino acids 26.2 (2004): 203-207.